[Disturbances in the Function of Cardiomyocyte Ryanodine Receptors of Spontaneously Hypertensive Rats Revealed by 4-chloro-m-cresol]

Biofizika. Nov-Dec, 2008  |  Pubmed ID: 19137689

The rates of Ca2+ release from sarcoplasmic reticulum in response to the activation of ryanodine receptors by 4-chloro-m-cresol in cardiomyocytes of three rat lines: spontaneously hypertensive (SHR) and normotensive WKY, and Wistar rats during five weeks of their growth and development have been studied to reveal differences in the function of ryanodine receptors at different stages of hypertension. Whereas the efflux of Ca2+ from sarcoplasmic reticulum in Wistar and WKY rat cardiomyocytes decreased in response to 4-chloro-m-cresol, an abrupt rise in the rate of [Ca2+]i increase was observed in myocytes of spontaneously hypertensive rats after 17 days of development. A correlation between this phenomenon and the occurrence of genetic defect of ryanodine receptors in SHR seems improbable because we did not register any differences in the rates of Ca2+ release from sarcoplasmic reticulum by the action of 4-chloro-m-cresol in concentrations 0.5-2.0 mM in the cardiomyocytes of newborn WKY and spontaneously hypertensive rats. On the other hand, pathological changes in the function of ryanodine receptors may become apparent later during ontogenesis. The connection of this phenomenon with an increase in the role of ryanodine receptors during the excitation-contraction coupling in muscle cell and an increase in the calpain expression by the age of 3 weeks in spontaneously hypertensive, but not in WKY rats, is discussed. It is supposed that the disintegration of the subunit of ryanodine receptors by calpain notably intensifies the Ca2+ release from sarcoplasmic reticulum after the activation of ryanodine receptors without affecting the characteristics of receptor binding.

[Extended Indications for Percutaneous Coronary Interventions After Successful Thrombolysis]

Angiologii͡a I Sosudistai͡a Khirurgii͡a = Angiology and Vascular Surgery. 2008  |  Pubmed ID: 19156030

The study compared the efficiency of percutaneous coronary interventions (PCI) into infarction-related coronary artery (IRCA) in high-risk patients with acute myocardial infarction (AMI), that were fulfilled 12-24 hours since the pain syndrome onset or during recurrent ischemic episodes 3 days after successful thrombolysis. In the first group (68 patients) invasive restoration of blood flow was fulfilled in 3 days (at average 48 hours) after AMI onset due to recurrent ischemia. In the second group (56 patients) IRCA recanalization was fulfilled in 12-24 hours (at average 20 hours) since pain syndrome onset due to clinical signs of unfavorable outcome high risk. IRCA recanalization was successful in 91% and 97% of cases in the first and second groups, respectively. In all cases injection of contrast media Ultravist 370 was diagnostically significant and visualized coronary arteries free of adverse events. In control group (conservative treatment) IRCA occlusion or subtotal stenosis was diagnosed in 18% and 39% of cases, respectively; stenosis >75% and <75% - in 27% and 16%, respectively. CONCLUSION: in high-risk patients with AMI percutaneous coronary interventions into IRCA can be effective 12-24 hours after successful thrombolytic therapy.

[Peculiarities of Synaptic Vesicle Recycling in Frog and Mouse Motor Nerve Terminals]

Zhurnal Evoliutsionnoĭ Biokhimii I Fiziologii. Nov-Dec, 2008  |  Pubmed ID: 19198161

Using electrophysiology and fluorescence microscopy (dye FM1-43), comparative study of neurotransmitter secretion, synaptic vesicle exo-endocytosis, and recycling has been carried out in frog and mouse motor nerve terminals during a long strong stimulation (3 min; 20 imp/s). The obtained data have revealed three synaptic vesicle pools and two recycling ways existing on motor nerve terminals. The strong stimulation induced consecutive depletion of readily releasable, mobilized, and reserve vesicle pools of frog nerve terminals. The exocytosis rate exceeded the endocytosis rate; predominant was the slow synaptic vesicle recycling that replenished the reserve pool. In mouse nerve endings, vesicles of the readily releasable and mobilized pools were only exocytosed, the pools being replenished by fast recycling. At the same time, exo- and endocytosis occurred nearly in parallel and vesicles of the reserve pool did not participate in the neurotransmitter secretion. In is suggested that evolution of motor nerve terminals was directed to a decrease of the vesicle pool size, economic spending, and effective reuse of synaptic vesicles. This is achieved by an increase of endocytosis and recycling rates. These features can provide a long maintenance of a quite level of neurotransmitter secretion in nerve terminals of homoiothermal animals to preserve reliability of synaptic transmission during the high-frequency activity.

Synthesis and Characterization of Bismuth(III) and Antimony(III) Calixarene Complexes

Inorganic Chemistry. Dec, 2008  |  Pubmed ID: 19228025

A series of calixarene bismuth and antimony complexes have been fully characterized by NMR, X-ray, IR, UV/vis, and elemental analysis. The reactions of SbCl(3) with the monosodium salt of p-tert-butylcalix[4]arene (Bu(t)C4), Bu(t)C4.Na, and the tetralithium salt of para-tert-butylcalix[4]arene, Bu(t)C4.Li(4), afforded two diantimony calix[4]arene complexes Bu(t)C4(SbCl)(2), with different (1)H NMR spectra and different THF coordination, but the same core structures. Other calix[4]arene antimony complexes (HC4(SbCl)(2) 2 and AC4(SbCl)(2) 3, diantimony chloride complexes of calix[4]arene and p-allylcalix[4]arene) and calix[4]arene bismuth complexes (Bu(t)C4(BiCl(2))(2)Li(2) 4, HC4(BiCl(2))(2)Li(2).6DMSO 5, and AC4(BiCl(2))(2)Li(2).4THF 6) were prepared by the reactions of MCl(3) (M = Sb or Bi) with RC4.Li(4) (R = Bu(t), H, or allyl) in a 2:1 molar ratio in THF. The same strategy was applied for Bu(t)C8 (p-tert-butylcalix[8]arene), and the desired bismuth complex [Bu(t)C8(BiCl(2))(4)(mu-Cl)(2)Li(6)][4THF.7DME] 12 was successfully synthesized. Complex 12 contains a planar Bi(4) core with four terminal chlorine atoms, which adopt a syn arrangement with respect to the plane defined by four bismuth atoms, and orient away from each other. A calix[4]arene monobismuth complex 11 was prepared by the reaction of Bi(OBu(t))(3) with the 1,2-disubstituted benzyl ether of calix[4]arene. Complexes 1-6 contain central planar M(2)(mu-O)(2) (M = Sb or Bi) four-membered rings, similar to four-membered rings observed in other calix[4]arene main group metal complexes. Intramolecular bismuth-arene pi interactions are observed in complexes 4-6 and 11 but not 12.

Excretion of Proteins by Rat Kidney During Various Types of Diuresis

Bulletin of Experimental Biology and Medicine. Dec, 2008  |  Pubmed ID: 19513351

Experiments on healthy rats showed that increased diuresis induced by administration of water, polyethylene glycol 400, furosemide, or 1-desamino-arginine-vasotocin is associated with increased protein excretion by the kidneys. The results can be explained by enhanced filtration of plasma proteins in glomeruli during polyuria of various geneses.

[Some Regularities in the Behavior of Radionuclides in Water of the Lakes Situated on the East-Urals Radioactive Trace]

Radiatsionnaia Biologiia, Radioecologiia / Rossiĭskaia Akademiia Nauk. Sep-Oct, 2008  |  Pubmed ID: 19004336

The paper presents the summary and the analysis of the results from a long-term monitoring of 90Sr specific activity in water of the lentic lakes Uruskul, L. Ighish, Kuyanysh and Travyanoye situated in Chelyabinsk Oblast on the East-Urals Radioactive Trace which was formed due to the 1957 accident at the Mayak PA. The data of measurements conducted over a 50-year period were approximated based on a function representing a sum of two (or three) exponents. The results of the analysis allowed us to study the peculiarities of reduction in the specific activity of 90Sr in the lakes of interest, and to obtain prognostic assessment of the development of the radioecological situation in these water reservoirs for the time period up to 2017. Presented in the paper are also data on the current levels of 90Sr and 137Cs specific activity in water of the lakes Uruskul, L. and S. Ighish, Kuyanysh, Travyanoye and Shablish. The estimates of the current reserves of these radionuclides are provided. Was shown that these lakes can be returned to the production use.

[Study of Hydroxyapatite Organic-mineral Complex Influence Upon Experimental Animals White Blood]

Stomatologiia. 2008  |  Pubmed ID: 19008819

Biological activity of newly synthesized organic-mineral complexes of hydroxyapatite with carboxymetilcellulose, carraginan and collagen has been studied by reaction of laboratory male rats white blood. The character of influence of each studied substance on the white blood was counted by the dynamic of general number of leukocyte, single leukocyte forms and morphological modification in them in peripheral blood before and after the intraperitoneal injection of the investigated materials. All of the 3 substances activated mechanisms of nonspecific resistance of organism and they were not allergens, because eozinophyllia didn't develop, and they were not toxic either: morphological modifications typical for pathology were absent in formal elements of white blood.

[Cognitive Disturbances in the Progression of Parkinson's Disease]

Zhurnal Nevrologii I Psikhiatrii Imeni S.S. Korsakova / Ministerstvo Zdravookhraneniia I Meditsinskoĭ Promyshlennosti Rossiĭskoĭ Federatsii, Vserossiĭskoe Obshchestvo Nevrologov [i] Vserossiĭskoe Obshchestvo Psikhiatrov. 2008  |  Pubmed ID: 19008846

Cognitive impairment (CD) have been studied in 88 patients with progressive Parkinson's disease (PD). It has been shown that CD in PD have a progressive character mostly due the increase of intensity of dysregulation and neurodynamic disorders, disturbances of visual-spatial functions and, in some cases, insufficiency of nominative speech function. A 2-5 years follow-up revealed the high frequency of transformation of moderate cognitive dysfunction into dementia. The old age of patients at baseline, late-onset and severity of disease were identified as predictors of CD progression in PD. The highest rate of CD progression was observed in patients with more pronounced premorbid disturbances of regulative and visual-spatial functions.

Fast Soft X-ray Images of Magnetohydrodynamic Phenomena in NSTX

The Review of Scientific Instruments. Oct, 2008  |  Pubmed ID: 19044583

A variety of magnetohydrodynamic (MHD) phenomena have been observed on NSTX. Many of these affect fast particle losses, which are of major concern for future burning plasma experiments. Usual diagnostics for studying these phenomena are arrays of Mirnov coils for magnetic oscillations and p-i-n diode arrays for soft x-ray emission from the plasma core. Data reported here are from a unique fast soft x-ray imaging camera (FSXIC) with a wide-angle (pinhole) tangential view of the entire plasma minor cross section. The camera provides a 64x64 pixel image, on a charge coupled device chip, of light resulting from conversion of soft x rays incident on a phosphor to the visible. We have acquired plasma images at frame rates of 1-500 kHz (300 frames/shot) and have observed a variety of MHD phenomena: disruptions, sawteeth, fishbones, tearing modes, and edge localized modes (ELMs). New data including modes with frequency >90 kHz are also presented. Data analysis and modeling techniques used to interpret the FSXIC data are described and compared, and FSXIC results are compared to Mirnov and p-i-n diode array results.

Magnetic Diagnostics for the Lithium Tokamak Experiment

The Review of Scientific Instruments. Oct, 2008  |  Pubmed ID: 19044600

The lithium tokamak experiment (LTX) is a spherical tokamak with R(0)=0.4 m, a=0.26 m, B(TF) approximately 3.4 kG, I(P) approximately 400 kA, and pulse length approximately 0.25 s. The focus of LTX is to investigate the novel low-recycling lithium wall operating regime for magnetically confined plasmas. This regime is reached by placing an in-vessel shell conformal to the plasma last closed flux surface. The shell is heated and then coated with liquid lithium. An extensive array of magnetic diagnostics is available to characterize the experiment, including 80 Mirnov coils (single and double axis, internal and external to the shell), 34 flux loops, 3 Rogowskii coils, and a diamagnetic loop. Diagnostics are specifically located to account for the presence of a secondary conducting surface and engineered to withstand both high temperatures and incidental contact with liquid lithium. The diagnostic set is therefore fabricated from robust materials with heat and lithium resistance and is designed for electrical isolation from the shell and to provide the data required for highly constrained equilibrium reconstructions.

The Motional Stark Effect Diagnostic for ITER Using a Line-shift Approach

The Review of Scientific Instruments. Oct, 2008  |  Pubmed ID: 19044666

The United States has been tasked with the development and implementation of a motional Stark effect (MSE) system on ITER. In the harsh ITER environment, MSE is particularly susceptible to degradation, as it depends on polarimetry, and the polarization reflection properties of surfaces are highly sensitive to thin film effects due to plasma deposition and erosion of a first mirror. Here we present the results of a comprehensive study considering a new MSE-based approach to internal plasma magnetic field measurements for ITER. The proposed method uses the line shifts in the MSE spectrum (MSE-LS) to provide a radial profile of the magnetic field magnitude. To determine the utility of MSE-LS for equilibrium reconstruction, studies were performed using the ESC-ERV code system. A near-term opportunity to test the use of MSE-LS for equilibrium reconstruction is being pursued in the implementation of MSE with laser-induced fluorescence on NSTX. Though the field values and beam energies are very different from ITER, the use of a laser allows precision spectroscopy with a similar ratio of linewidth to line spacing on NSTX as would be achievable with a passive system on ITER. Simulation results for ITER and NSTX are presented, and the relative merits of the traditional line polarization approach and the new line-shift approach are discussed.

[The First Experience of Using 64-cut Computer-tomography Coronary Angiography for Clinical Examination of Officer Staff]

Voenno-medit͡sinskiĭ Zhurnal. Sep, 2008  |  Pubmed ID: 19048849

The article presents the estimations of capabilities of visualization of coronary arteria using 64-cut multispin computer tomography (MSCTCA) for the purpose of it's using for early detection of coronary atersclerosis. There were examined 50 patients (42 men and 8 women) in the age of 29-78 years old. There was realized an analyze of frequency of occurrence of coronary artersclerosis in dependence of age. By 8 patients data of MSCTCA and KAG were compared. A high frequency of coincidence of results of the researches (88%) was determined. Also were determined evidences for realizing both of these methods. Causes of potential faults of data interpretation were discovered. MSCTCA--a high-effective method of diagnostics of coronary artersclerosis and detection of character and value of stenotic damage of coronary arteria. Received data permit determine practicability of further realization of interventional radiology.

Catalytic Role of Calix[4]hydroquinone in Acetone-water Proton Exchange: a Quantum Chemical Study of Proton Transfer Via Keto-enol Tautomerism

The Journal of Physical Chemistry. A. Oct, 2008  |  Pubmed ID: 18800781

Calix[4]hydroquinone has recently attracted considerable interest since it forms stable tubular aggregates mediated solely by hydrogen bonding and pi-pi-stacking interactions. These aggregates trap specifically various small organic molecules and, in particular, catalyze the proton exchange of water with acetone. Using correlated quantum chemical methods, the mechanism of the observed proton exchange mediated by keto-enol tautomerism of acetone is investigated in detail. Starting with an investigation of keto-enol tautomerism of acetone-water clusters, it appears that four catalytic water molecules are optimal for the catalysis and that additional solvent water molecules lead to a decrease in efficiency. Analyses of the partial charges revealed a decrease of the polarization of the reactive hydrogen bonds due to the additional water molecules. As a next step, hydroquinone-acetone-water complexes were studied as models for the situation in the CHQ moieties. However, the computations revealed that the proton transfer reaction becomes less efficient when one catalytic water molecule is replaced by hydroquinone. Although concerted proton transfer via keto-enol tautomerism of acetone seems to be the predominant mechanism in supercritical water, it is no longer the rate-determining reaction mechanism for the catalyzed acetone-water proton exchange observed in tubular CHQ. Nevertheless, a key feature of the catalytic function of tubular CHQ has been identified to be the stiff hydrogen bonding network and the exclusion of additional solvent water molecules.

[Polymorphism of Yellow Locus in Drosophila Melanogaster from Natural Populations]

Tsitologiia. 2008  |  Pubmed ID: 18822793

We studied molecular characteristics of yellow (y; 1-0.0) locus, which determines the body coloration of phenotypically wild-type and mutant alleles isolated from geographically distant populations of Drosophila melanogaster in different years. According to Southern data, restrictions map of yellow locus of all studied strains differ from each other as well as from that of Oregon stock. FISH analysis shows that in the neighborhood of yellow locus in X chromosome neither P nor hobo elements are found in y1-775 stock, while only hobo is found there in y1-859 and y1-866 stocks, only P element in y+sn849 stock, and both elements in y1-719 stock. Thus, all studied mutant variants of yellow are of independent origin. Yellow locus residing at the very end of X chromosome (region 1A5-8 of cytologic map) carries significantly more transposon than retrotransposon-induced mutations, as compared to white locus (regions 3C2). It is possible that transposons are more active than retrotransposons at the chromosomal ends of D. melanogaster.

Synthesis of Substituted Naphthalenes Via a Catalytic Ring-expansion Rearrangement

Organic Letters. Nov, 2008  |  Pubmed ID: 18834135

A new methodology for the preparation of substituted naphthalenes starting from readily available indenones, organometal reagents, and trimethylsilyldiazomethane via a catalytic rearrangement process is described. Hindered biaryl naphthalenes, including triortho-substituted biaryls, can be accessed through our method. Our results are consistent with a mechanism involving a benzobenzvalene intermediate.

Dynamical Dzyaloshinsky-Moriya Interaction in KCuF3

Physical Review Letters. Oct, 2008  |  Pubmed ID: 18851575

The spin dynamics of the prototypical quasi-one-dimensional antiferromagnetic Heisenberg spin S=1/2 chain KCuF3 is investigated by electron spin resonance spectroscopy. Our analysis shows that the peculiarities of the spin dynamics require a new dynamical form of the antisymmetric anisotropic spin-spin interaction. This dynamical Dzyaloshinsky-Moriya interaction is related to strong oscillations of the bridging fluorine ions perpendicular to the crystallographic c axis. This new mechanism allows us to resolve consistently the controversies in observation of the magnetic and structural properties of this orbitally ordered perovskite compound.

Synthesis of Heterometallic Group 13 Nanoclusters and Inks for Oxide Thin-film Transistors

Angewandte Chemie (International Ed. in English). 2008  |  Pubmed ID: 18973216

Primary Events in the Colicin Translocon: FRET Analysis of Colicin Unfolding Initiated by Binding to BtuB and OmpF

Biochemistry. Dec, 2008  |  Pubmed ID: 18986168

Cellular import of colicin E3 is initiated by high affinity binding of the colicin receptor-binding (R) domain to the vitamin B(12) (BtuB) receptor in the Escherichia coli outer membrane. The BtuB binding site, at the apex of its extended coiled-coil R-domain, is distant from the C-terminal nuclease domain that must be imported for expression of cytotoxicity. Based on genetic analysis and previously determined crystal structures of the R-domain bound to BtuB, and of an N-terminal disordered segment of the translocation (T) domain inserted into the OmpF porin, a translocon model for colicin import has been inferred. Implicit in the model is the requirement for unfolding of the colicin segments inserted into OmpF. FRET analysis was employed to study colicin unfolding upon interaction with BtuB and OmpF. A novel method of Cys-specific dual labeling of a native polypeptide, which allows precise placement of donor and acceptor fluorescent dyes on the same polypeptide chain, was developed. A decrease in FRET efficiency between the translocation and cytotoxic domains of the colicin E3 was observed upon colicin binding in vitro to BtuB or OmpF. The two events were independent and additive. The colicin interactions with BtuB and OmpF have a major electrostatic component. The R-domain Arg399 is responsible for electrostatic interaction with BtuB. It is concluded that free energy for colicin unfolding is provided by binding of the R- domain to BtuB and binding/insertion of the T-domain to/into OmpF.

Comparison of Pharmacokinetic and Pharmacodynamic Profiles of Aspirin Following Oral Gavage and Diet Dosing in Rats

Chemico-biological Interactions. May, 2009  |  Pubmed ID: 18992230

Aspirin is one of the oldest drugs and has been purported to have multiple beneficial effects, including prevention of cardiovascular disease and cancer, in addition to its original indication for treatment of inflammation, fever and pain. In cancer chemoprevention studies using animal models, two methods of aspirin administration have been employed: oral gavage and diet. The untested assumption was that exposure and the resultant pharmacological effects are similar for these two administration methods when dosing is normalized on the basis of mg/kg body weight/day. This study examined and compared time-dependent plasma and colon mucosal concentrations of aspirin metabolite salicylate (aspirin concentrations were below level of quantification), plasma thromboxane B(2) concentrations, and colon mucosal prostaglandin E(2) concentration following these two different dosing paradigms in rats. Diet dosing yielded relatively constant plasma and colon salicylate concentration vs. time profiles. On the other hand, oral gavage dosing led to a rapid peak followed by a fast decline in salicylate concentration in both plasma and colon. Nevertheless, the exposure as measured by the area under plasma or colon concentration-time curve of salicylate was linearly related to dose irrespective of the dosing method. Linear relationships were also observed between colon and plasma salicylate areas under the curve and between colon prostaglandin E(2) and plasma thromboxane B(2) areas under the curve. Therefore, more easily accessible plasma salicylate and thromboxane B(2) concentrations were representative of the salicylate exposure and prostaglandin E(2) pharmacodynamic biomarker in the target colon, respectively.

[About Sensitive of Erythroblastic Islands Bone Marrow of Polycythemic Reds to Erythropoietin]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Nov, 2009  |  Pubmed ID: 20058817

The sensibility to erythropoietin oferythroblastic islands of bone marrow which were made in different terms after the creation of transfusion polycytemia is researched. It turned out that the central macrophags of involuting erythroblastic islands are more sensible to erythropoietin than residual macrophags of bone marrow. The capability of residual macrophags to form erythroblastic islands is opened to the bigger inhibitory influence during the development of transfusion polycytemia than to the central macrjphags of involuting erythroblastic islands.

[The Investigation of Dynamic Changes of Erythropoietin Content of the Erythroblast Island Cultures]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Nov, 2009  |  Pubmed ID: 20058818

Dynamic changes of erythropoietin content on the 6th, 12th, 24 and 48th hours of cultivation in bone marrow erythropoietic island liquid short-term cultures were investigated. The initial doses of 0.25, 0.5, 1 mE/ml oferythropoietin was used, and one series with no erythropoietin as control. In culture with 0.25 mE/ml of erythropoietin, its reduction was registered from the 6th to 48th hours of cultivation with relatively lower number of erythroblast islands in state of involution, and a higher number in the state of reconstruction. In cultures with 0.5 mE/ml oferythropoietin, the same erythropoietin reduction was registered with relatively higher numbers of erythroblast islands in the state of reconstruction, and with an unexpected elevation of erythropoietin concentration on the 48th hour of cultivation. In cultures with 1 mE/ml oferythropoietin, such unexpected rise in erythropoietin content was registered in 24 hours, accompanied by relatively higher number of erythroblast islands in the state of reconstruction.

Photoemission Electron Microscopy Using Extreme Ultraviolet Attosecond Pulse Trains

The Review of Scientific Instruments. Dec, 2009  |  Pubmed ID: 20059146

We report the first experiments carried out on a new imaging setup, which combines the high spatial resolution of a photoemission electron microscope (PEEM) with the temporal resolution of extreme ultraviolet (XUV) attosecond pulse trains. The very short pulses were provided by high-harmonic generation and used to illuminate lithographic structures and Au nanoparticles, which, in turn, were imaged with a PEEM resolving features below 300 nm. We argue that the spatial resolution is limited by the lack of electron energy filtering in this particular demonstration experiment. Problems with extensive space charge effects, which can occur due to the low probe pulse repetition rate and extremely short duration, are solved by reducing peak intensity while maintaining a sufficient average intensity to allow imaging. Finally, a powerful femtosecond infrared (IR) beam was combined with the XUV beam in a pump-probe setup where delays could be varied from subfemtoseconds to picoseconds. The IR pump beam could induce multiphoton electron emission in resonant features on the surface. The interaction between the electrons emitted by the pump and probe pulses could be observed.

Quasi-free-standing Epitaxial Graphene on SiC Obtained by Hydrogen Intercalation

Physical Review Letters. Dec, 2009  |  Pubmed ID: 20366220

Quasi-free-standing epitaxial graphene is obtained on SiC(0001) by hydrogen intercalation. The hydrogen moves between the (6 square root(3) x 6 square root(3))R30 degrees reconstructed initial carbon layer and the SiC substrate. The topmost Si atoms which for epitaxial graphene are covalently bound to this buffer layer, are now saturated by hydrogen bonds. The buffer layer is turned into a quasi-free-standing graphene monolayer with its typical linear pi bands. Similarly, epitaxial monolayer graphene turns into a decoupled bilayer. The intercalation is stable in air and can be reversed by annealing to around 900 degrees C.

New A2/3-xRh2O4 Compounds with the CaFe2O4 Structure Where A is a Rare Earth or Bi

Inorganic Chemistry. Jan, 2009  |  Pubmed ID: 19049419

New compounds of the type R(2/3-x)Rh(2)O(4) with the CaFe(2)O(4) structure have been prepared, where R is a rare earth. For crystals grown in a Bi/V/O flux, the rare earth was partially replaced by Bi. No evidence of ordering of the A cation vacancies is found, but the A cations are displaced from the ideal A cation site by about 0.24 A. Electrical conductivity measurements on crystals suggest that the materials are degenerate semiconductors with Seebeck measurements showing p-type behavior. This is consistent with our observation that x in R(2/3-x)Rh(2)O(4) ranges up to about 0.09. The compounds were also characterized by magnetic susceptibility and diffuse reflectance measurements.

Specific Microsolvation Triggers Dissociation-mediated Anomalous Red-shifted Fluorescence in the Gas Phase

Journal of the American Chemical Society. Jan, 2009  |  Pubmed ID: 19072655

Ion-depletion IR spectroscopy has revealed that at least two water molecules are required in complexes with 4-(dimethylamino)benzoic acid methyl ester (DMABME) for anomalous red-shifted fluorescence to occur in the gas phase. Through the use of high-level quantum-chemical calculations, two experimentally observed isoenergetic isomers are assigned to complexes in which a water dimer is hydrogen-bonded either to the carbonyl oxygen of the ester function or to the amino nitrogen. Surprisingly, computed IR spectra reveal that the N-bonded isomer is responsible for the observed red-shifted fluorescence. For an explanation, the mechanism of twisted intramolecular charge-transfer (TICT) formation and energy dissipation is investigated in detail. In general, for red-shifted fluorescence to occur, the N-bonded complexes must be able to dissipate energy, which in the gas phase can only happen nonradiatively via fragmentation. Arguments are given that only the N-bonded isomer photodissociates rapidly enough into free DMABME and a water dimer as a result of the immediate repulsion between the amino nitrogen and the water dimer in the TICT state. The O-bonded isomer, on the other hand, stays intact because the hydrogen bond is strengthened by additional electrostatic attraction in the ICT state. Furthermore, an experiment to further corroborate that mechanism is suggested.

A Hybrid Organic/inorganic Benzene

Angewandte Chemie (International Ed. in English). 2009  |  Pubmed ID: 19105174

Bismuth Aryloxides

Inorganic Chemistry. Dec, 2009  |  Pubmed ID: 19883110

The synthesis and full characterization (mp, NMR, UV/vis, FTIR, and elemental analysis) of 13 bismuth aryloxides are reported. We have prepared bismuth aryloxides with alkyl, aryl, and allylic substituents on the aryl rings. Eleven of these bismuth aryloxides have been characterized with single crystal X-ray diffraction methods. Bismuth-donor interactions (donor = aryl, methoxy) are observed in several cases. Three unexpected bismuth oxo aryloxides (6c, 9c, 11c) were also isolated. Complex C(77)H(102)Bi(4)Br(6)O(8) (6c) results from apparent C-H activation and Bi-C bond formation as a sideproduct in the synthesis of Bi(O-2,6-(i)Pr(2)-4-BrC(6)H(2))(3) (6). Cluster 9c has a Bi(32)O(56) core, and cluster C(90)H(90)Bi(4)Li(2)O(12) (11c) is the second lithium bismuth oxo cluster reported to date.

Copper(I)/O2 Chemistry with Imidazole Containing Tripodal Tetradentate Ligands Leading to Mu-1,2-peroxo-dicopper(II) Species

Inorganic Chemistry. Dec, 2009  |  Pubmed ID: 19886646

Cuprous and cupric complexes with the new imidazolyl containing tripodal tetradentate ligands {L(MIm), (1H-imidazol-4-yl)-N,N-bis((pyridin-2-yl)methyl)methanamine, and L(EIm), 2-(1H-imidazol-4-yl)-N,N-bis((pyridin-2-yl)methyl)ethanamine}, have been investigated to probe differences in their chemistry, especially in copper(I)-dioxygen chemistry, compared to that already known for the pyridyl analogue TMPA, tris(2-pyridyl)methyl)amine. Infrared (IR) stretching frequencies obtained from carbon monoxide adducts of [(L(MIm))Cu(I)](+) (1a) and [(L(EIm))Cu(I)](+) (2a) show that the imidazolyl donor is stronger than its pyridyl analogue. Electrochemical data suggest differences in the binding constant of Cu(II) to L(EIm) compared to TMPA and L(MIm), reflecting geometric changes. Oxygenation of [(L(MIm))Cu(I)](+) (1a) in 2-methyltetrahydrofuran (MeTHF) solvent at -128 degrees C leads to an intensely purple colored species with a UV-vis spectrum characteristic of an end-on bound peroxodicopper(II) complex [{(L(MIm))Cu(II)}(2)(mu-1,2-O(2)(2-))](2+) (1b(P)) {lambda(max) = 528 nm}, very similar to the previously well characterized complex [{(TMPA)Cu(II)}(2)(mu-1,2-O(2)(2-))](2+) {lambda(max) = 520 nm (epsilon = 12 000 M(-1) cm(-1)), in MeTHF; resonance Raman (rR) spectroscopy: nu(O-O) = 832 (Delta((18)O(2)) = -44) cm(-1)}. In the low-temperature oxygenation of 2a, benchtop (-128 degrees C) and stopped-flow (-90 degrees C) experiments reveal the formation of an initial superoxo-Cu(II) species [(L(EIm))Cu(II)(O(2)(*-))](+) (2b(S)), lambda(max) = 431 nm in THF) . This converts to the low-temperature stable peroxo complex [{(L(EIm))Cu(II)}(2)(mu-1,2-O(2)(2-))](2+) (2b(P)) {rR spectroscopy: nu(O-O) = 822 (Delta((18)O(2)) = -46) cm(-1)}. Complex 2b(P) possess distinctly reduced Cu-O and O-O stretching frequencies and a red-shifted UV-vis feature {to lambda(max) = 535 nm (epsilon = 11 000 M(-1) cm(-1))} compared to the TMPA analogue due to a distortion from trigonal bipyramidal (TBP) to a square pyramidal ligand field. This distortion is supported by the structural characterization of related ligand-copper(II) complexes: A stable tetramer cluster complex [(mu(2)-L(EIm-))(4)(Cu(II))(4)](4+), obtained from thermal decomposition of 2b(P) (with formation of H(2)O(2)), also exhibits a distorted square pyramidal Cu(II) ion geometry as does the copper(II) complex [(L(EIm))Cu(II)(CH(3)CN)](2+) (2c), characterized by X-ray crystallography and solution electron paramagnetic resonance (EPR) spectroscopy.

[Some Problems in Rehabilitating Disabled People with Multiple Sclerosis in Agencies for Social Protection]

Zhurnal Nevrologii I Psikhiatrii Imeni S.S. Korsakova / Ministerstvo Zdravookhraneniia I Meditsinskoĭ Promyshlennosti Rossiĭskoĭ Federatsii, Vserossiĭskoe Obshchestvo Nevrologov [i] Vserossiĭskoe Obshchestvo Psikhiatrov. 2009  |  Pubmed ID: 19891357

The state social policy with regard to disable people in the Russian Federation is developed in accordance with international instruments which include the "Declaration on the Rights of People with Disabilities" adopted by the UN General Assembly, the ILO Convention (No159) "Vocational Rehabilitation and Employment of Disabled Persons", the "Standard Rules on the Equalization of Opportunities for Persons with Disabilities" adopted by the UN General Assembly, the World Program of Action Concerning Disabled Persons etc. All these instruments mainly focus on the issue of social rehabilitation of people with health disabilities in order to offer them "equal opportunities" in different areas of their life. The paper is devoted to research of some backbone arrangements of rehabilitation of people with multiple sclerosis (MS) and major lines of proficiency training and retraining of professionals on issues of social rehabilitation of people with health disabilities as well as methods of rehabilitation of MS patients.

[Influence of Complex Rehabilitation on the Social Adaptability and Quality of Life in People with Multiple Sclerosis]

Zhurnal Nevrologii I Psikhiatrii Imeni S.S. Korsakova / Ministerstvo Zdravookhraneniia I Meditsinskoĭ Promyshlennosti Rossiĭskoĭ Federatsii, Vserossiĭskoe Obshchestvo Nevrologov [i] Vserossiĭskoe Obshchestvo Psikhiatrov. 2009  |  Pubmed ID: 19891359

The article presents results of complex rehabilitation in people with multiple sclerosis. We have studied the effect of rehabilitation measures on quality of life and self-sustenance adaptability of patients with multiple sclerosis as compared to standard therapeutic interventions. Factors influencing the effectiveness of rehabilitation measures are discussed.

Effect of Electric Field and Temperature Gradient on the Orientational Dynamics of Liquid Crystals in a Microvolume Cylindrical Cavity

The Journal of Chemical Physics. Oct, 2009  |  Pubmed ID: 19894973

We have considered a homogeneously aligned liquid crystal (HALC) microvolume confined between two infinitely long horizontal coaxial cylinders and investigated dynamic field pumping, i.e., studied the interactions between director, velocity, and electric E fields as well as a radially applied temperature gradient inverted Delta T, where the inner cylinder is kept at a lower temperature than the outer one. In order to elucidate the role of inverted Delta T in producing hydrodynamic flow u, we have carried out a numerical study of a system of hydrodynamic equations including director reorientation, fluid flow, and temperature redistribution across the HALC cavity. Calculations show that only under the influence of inverted Delta T does the initially quiescent HALC sample settle down to a stationary flow regime with horizontal component of velocity u(eq)(r). The effects of inverted Delta T and of the size of the HALC cavity on magnitude and direction of u(eq)(r) have been investigated for a number of hydrodynamic regimes. Calculations also showed that E influences only the director redistribution across the HALC but not the magnitude of the velocity u(eq)(r).

[On the Erythropoietin Effect on the Cell Proliferative Activity in the Culture of Th Erythroblastic Islands of the Rat Bone Marrow in Transfusion Polycytemia]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Sep, 2009  |  Pubmed ID: 19899711

The effect of experimental inhibition of the erythropoiesis on ability of the erythroide "crown" cells of erythroblast islands of the bone marrow to respond to the erythropoietin by the increase of the proliferative activity was studied. It was discovered that this ability depended on the degree of the erythropoiesis inhibition and on the class of the erythroblast island maturity. In the culture of the erythroblast islands of the bone marrow on the second 24-hour period after transfusion polycytemia reproduction, the proliferative activity of the erythroid cells in response to brining of the erythropoietin to the culture increased more in the erythroblast islands of the first and second maturity classes than in the reconstructing the erythroblast islands. In the culture of the bone marrow erythroblast islands evolved on the fifth 24-hour period after the reproduction transfusion polycytemia, the erythroblast islands of the first and second maturity classes were absent, and the proliferative activity of the erythroid cells of the reconstructing erythroblast islands in response to brining the erythropoietin to the culture increased to a lesser degree than in reconstructing erythroblast islands of the bone marrow evolved on the second 24-hour period after the polycytemia transfusion reproduction.

[On Erythropoietin Level Formation in the Blood Under Conditions of Acute Disturbance of Cardiac Function]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Sep, 2009  |  Pubmed ID: 19899712

The erythropoietin levels in the blood of 50 patients with myocardial infarction were studied. The control group consisted of 33 patients with gastroenterologic diseases. Increased erythropoietin production in patients with myocardial infarction was caused by blood hypoxia under conditions of keeping kidney erythropoietin function. No dependence was found between manifestation of heaviness of acute heart failure caused by acute myocardial ischemic and hormone production in patients without anemia.

Liquid-crystal Pumping in a Cylindrical Capillary with Radial Temperature Gradient

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Sep, 2009  |  Pubmed ID: 19905132

Dynamic field pumping principle has been developed utilizing the interactions of both the director and velocity fields and a temperature gradient inverted deltaT. The orientational dynamics in the hybrid-oriented liquid-crystal (HOLC) microvolume confined between two infinitely long coaxial cylinders under the influence of the radially directed inverted deltaT has been investigated. We have carried out a numerical study of a system of hydrodynamic equations including director reorientation, fluid flow, and temperature redistribution across the HOLC cavity between two cylinders under the influence of inverted deltaT, when the liquid-crystal cavity is heated both from outer (inner) to inner (outer) bounding cylinders. Calculations show that under the influence of inverted deltaT the initially quiescent HOLC drop settles down to a stationary flow regime, with the horizontal u(st)(r) component of velocity. The effects of inverted deltaT , of the character of the preferred anchoring of the average molecular direction to the restricted cylinders, and of the size of the HOLC cavity on magnitude and direction of hydrodynamic flow--for a number of hydrodynamic regimes--has been investigated.

Director Reorientation in a Hybrid-oriented Liquid-crystal Film Induced by Thermomechanical Effect

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Sep, 2009  |  Pubmed ID: 19905135

We have carried out a numerical study of a system of hydrodynamic equations including director reorientation, fluid flow, and temperature redistribution across a two-dimensional (2D) hybrid-oriented liquid-crystal (HOLC) cell under the influence of a heat flow directed normal to the upper bounding surface, whereas on the rest boundaries the temperature is kept constant. Calculations based upon the nonlinear extension of the classical Ericksen-Leslie theory shows that the HOLC material under the influence of the heat flow, after some time, more than the time of relaxation, for instance, of the director field in the HOLC cell, settles down to the rest state regime, where the horizontal and vertical components of the velocity vector are equal to zero, and the temperature field across the LC cell finally reaches the value of temperature on the lower and two lateral bounding surfaces. The role of hydrodynamic flow in the relaxation processes of the temperature field to its equilibrium distribution across the 2D HOLC cell, containing 4-n-pentyl-4'-cyanobiphenyl, has been investigated, for a number of dynamic regimes.

All-fiber Coherent Combining of Er-doped Amplifiers Through Refractive Index Control in Yb-doped Fibers

Optics Letters. Nov, 2009  |  Pubmed ID: 19927215

We propose a simple all-fiber solution for coherent beam combining of Er-doped fiber amplifiers. This method, which we believe to be a new method, employs the effect of refractive index changes in Yb-doped fibers induced at approximately 1.55 microm by optical pumping at approximately 980 nm, which is performed for an active phase control in the fiber configuration. An algorithm based on population inversion in a two-level system supports the straightforward implementation of the effect into a feedback loop. Combining two 500 mW Er-doped amplifiers in a single-mode fiber is successfully demonstrated with control by approximately 120 mW laser diode. The method is shown to operate against the acoustic phase noise within the range of approximately pi rad and with a rate of approximately 2.6 pi rad/ms that potentially serves combining of at least 50 amplifiers similar to those used in practical work.

[Effectiveness of Treatment of Single Cerebral Metastasis Depending on Prognostic Groups (RPA RTOG)]

Voprosy Onkologii. 2009  |  Pubmed ID: 19514377

Our investigation was aimed at establishing a relationship between single metastases in the brain and a set of prognostic factors. It involved 278 patients treated at the Center in 1983-2003. The whole brain was irradiated in 273 while 159 of them (58.2%) received additional local irradiation of the brain. Single dosage of 2-2.5 Gy was administered to 158 (57.9%), 115--3Gy and more (42.1%). Mean total dosage was 36 Gy per metastasis for the whole brain and 46 Gy--for total plus local exposure. Among patients with favorable prognosis (RPA) were those aged up to 65, Karnofsky's index > or = 70%, with cured or controllable tumor and without extracranial metastases; poor prognosis--Karnofsky's index < or = 70%, irrespective of any other prognosticators, and intermediate prognosis--the remaining cases. The following four treatment modalities were used: 1) surgery --> radio- or radiochemotherapy (40); 2) chemotherapy > or = radiotherapy --> chemotherapy successively (56); (3) radiotherapy alone (110) and (4) simultaneous radiochemotherapy (72).

[Efficiency of Retrosternal Lymphotropic Chemotherapy in the Treatment of New Cases of Destructive Pulmonary Tuberculosis]

Problemy Tuberkuleza I Bolezneĭ Legkikh. 2009  |  Pubmed ID: 19514450

The efficiency of treatment was evaluated in 2 groups of new tuberculosis cases discharging drug-resistant Mycobacterium tuberculosis. The authors' method of retrosternal lymphotropic administration of drugs was used in the complex of treatment in a study group of 96 patients; a control group (n = 93) received only combined chemotherapy. The treatment method showed a high efficiency in the treatment of new cases of destructive pulmonary tuberculosis, including acutely progressive forms and caseous pneumonia. Bacterial discharge cessation and decay cavity closure were increased by 26.9% and 27.2%, respectively. The abacillation rate increment was 32.9% for acutely progressive processes and 41.2% for caseous pneumonia. The authors show the efficiency of the method in treating bronchial or laryngeal tuberculosis and the expediency of applying the retrosternal procedure during preoperative preparation.

[Modern Ceramic Materials Used in Prosthetic Stomatology for Dentures Making]

Stomatologiia. 2009  |  Pubmed ID: 19517643

Nonlinear Layered Lattice Model and Generalized Solitary Waves in Imperfectly Bonded Structures

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. May, 2009  |  Pubmed ID: 19518581

We study nonlinear waves in a two-layered imperfectly bonded structure using a nonlinear lattice model. The key element of the model is an anharmonic chain of oscillating dipoles, which can be viewed as a basic lattice analog of a one-dimensional macroscopic waveguide. Long nonlinear longitudinal waves in a layered lattice with a soft middle (or bonding) layer are governed by a system of coupled Boussinesq-type equations. For this system we find conservation laws and show that pure solitary waves, which exist in a single equation and can exist in the coupled system in the symmetric case, are structurally unstable and are replaced with generalized solitary waves.

Protonation Activates Anion Binding and Alters Binding Selectivity in New Inherently Fluorescent 2,6-bis(2-anilinoethynyl)pyridine Bisureas

Chemical Communications (Cambridge, England). May, 2009  |  Pubmed ID: 19532876

A new class of 2,6-bis(2-anilinoethynyl)pyridine-based bisureas forms 1 : 1 complexes with halides; protonation enhances binding by over one order of magnitude, alters the binding selectivity, and provides a colorimetric indication of anion binding.

[Retrosternal Lymphotropic Chemotherapy and Pneumoperitoneum in the Treatment of Drug-resistant Destructive Pulmonary Tuberculosis]

Problemy Tuberkuleza I Bolezneĭ Legkikh. 2009  |  Pubmed ID: 19565808

The efficiency of combined treatment with retrosternal lymphotropic administration of drugs and pneumoperitoneum was comparatively analyzed in 148 new cases of destructive pulmonary tuberculosis. Both methods were applied during combined chemotherapy in a study group of 48 patients. In Group 2 (n = 54), lymphotropic procedure was employed alone during standard chemotherapy; in Group 3 (n = 46), only pneumoperitoneum was used in combination of chemotherapy. In 40 patients, pulmonary tuberculosis was acutely progressive. Drug resistance was identified in 81.7%, including multidrug resistance in 27.7%. With the combined use of retrosternal lymphotropic therapy and pneumoperitoneum, bacterial excretion ceased in 96.2% of new cases of drug-resistant tuberculosis; decay cavity resolved in 80.8%. The proposed therapeutic technology used in patients with persistent bacterial excretion and decay cavities after ineffective 4-9-month treatment could achieve abacillation in 90.9% of patients and resolve decay cavities in 77.3%. Retrosternal drug injection reduces a risk for complications due to bronchial tuberculosis involvement when pneumoperitoneum is applied.

Location of the Beta 4 Transmembrane Helices in the BK Potassium Channel

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience. Jul, 2009  |  Pubmed ID: 19571123

Large-conductance, voltage- and Ca(2+)-gated potassium (BK) channels control excitability in a number of cell types. BK channels are composed of alpha subunits, which contain the voltage-sensor domains and the Ca(2+)- sensor domains and form the pore, and often one of four types of beta subunits, which modulate the channel in a cell-specific manner. beta 4 is expressed in neurons throughout the brain. Deletion of beta 4 in mice causes temporal lobe epilepsy. Compared with channels composed of alpha alone, channels composed of alpha and beta 4 activate and deactivate more slowly. We inferred the locations of the two beta 4 transmembrane (TM) helices TM1 and TM2 relative to the seven alpha TM helices, S0-S6, from the extent of disulfide bond formation between cysteines substituted in the extracellular flanks of these TM helices. We found that beta 4 TM2 is close to alpha S0 and that beta 4 TM1 is close to both alpha S1 and S2. At least at their extracellular ends, TM1 and TM2 are not close to S3-S6. In six of eight of the most highly crosslinked cysteine pairs, four crosslinks from TM2 to S0 and one each from TM1 to S1 and S2 had small effects on the V(50) and on the rates of activation and deactivation. That disulfide crosslinking caused only small functional perturbations is consistent with the proximity of the extracellular ends of TM2 to S0 and of TM1 to S1 and to S2, in both the open and closed states.

Low Temperature Ga Surface Diffusion from Focused Ion Beam Milled Grooves

Nanotechnology. Aug, 2009  |  Pubmed ID: 19620748

Ga diffusion from focused ion beam (FIB) milled grooves has been studied using x-ray photoemission electron microscopy (XPEEM) and mirror electron microscopy (MEM). We analyze the surface chemistry of the FIB structures measuring the Ga presence in the top layers of the milled grooves and morphological defects inside the grooves. The Ga is initially strictly confined to the grooves. However, annealing at temperatures as low as 150 degrees C leads to rapid and significant Ga surface diffusion from the FIB structures. The out-diffused Ga forms a thin layer extending up to several microns laterally in a non-regular pattern. The diffusion is significantly enhanced at small crystallites at the edges of the grooves. We explain the general behavior with an atomic scale model in which interstitial Ga in the milled areas diffuses out and substitutes silanol groups on the surface.

Multiple Origins of Foot-and-mouth Disease Virus Serotype Asia 1 Outbreaks, 2003-2007

Emerging Infectious Diseases. Jul, 2009  |  Pubmed ID: 19624919

We investigated the molecular epidemiology of foot-and-mouth disease virus (FMDV) serotype Asia 1, which caused outbreaks of disease in Asia during 2003-2007. Since 2004, the region affected by outbreaks of this serotype has increased from disease-endemic countries in southern Asia (Afghanistan, India, Iran, Nepal, Pakistan) northward to encompass Kyrgyzstan, Tajikistan, Uzbekistan, several regions of the People's Republic of China, Mongolia, Eastern Russia, and North Korea. Phylogenetic analysis of complete virus capsid protein 1 (VP1) gene sequences demonstrated that the FMDV isolates responsible for these outbreaks belonged to 6 groups within the Asia 1 serotype. Some contemporary strains were genetically closely related to isolates collected historically from the region as far back as 25 years ago. Our analyses also indicated that some viruses have spread large distances between countries in Asia within a short time.

Hidden Chromosome Symmetry: in Silico Transformation Reveals Symmetry in 2D DNA Walk Trajectories of 671 Chromosomes

PloS One. 2009  |  Pubmed ID: 19636424

Maps of 2D DNA walk of 671 examined chromosomes show composition complexity change from symmetrical half-turn in bacteria to pseudo-random trajectories in archaea, fungi and humans. In silico transformation of gene order and strand position returns most of the analyzed chromosomes to a symmetrical bacterial-like state with one transition point. The transformed chromosomal sequences also reveal remarkable segmental compositional symmetry between regions from different strands located equidistantly from the transition point. Despite extensive chromosome rearrangement the relation of gene numbers on opposite strands for chromosomes of different taxa varies in narrow limits around unity with Pearson coefficient r = 0.98. Similar relation is observed for total genes' length (r = 0.86) and cumulative GC (r = 0.95) and AT (r = 0.97) skews. This is also true for human coding sequences (CDS), which comprise only several percent of the entire chromosome length. We found that frequency distributions of the length of gene clusters, continuously located on the same strand, have close values for both strands. Eukaryotic gene distribution is believed to be non-random. Contribution of different subsystems to the noted symmetries and distributions, and evolutionary aspects of symmetry are discussed.

Experimental Equilibrium Structures: Application of Molecular Dynamics Simulations to Vibrational Corrections for Gas Electron Diffraction

The Journal of Physical Chemistry. A. Jul, 2009  |  Pubmed ID: 19645487

A general method is described that allows experimental equilibrium structures to be determined from gas electron diffraction (GED) data. Distance corrections, starting values for amplitudes of vibration and anharmonic "Morse" constants (all required for a GED refinement) have been extracted from molecular dynamics (MD) simulations. For this purpose MD methods have significant advantages over traditional force-field methods, as they can more easily be performed for large molecules, and, as they do not rely on extrapolation from equilibrium geometries, they are highly suitable for molecules with large-amplitude and anharmonic modes of vibration. For the test case Si(8)O(12)Me(8), where the methyl groups rotate and large deformations of the Si(8)O(12) cage are observed, the MD simulations produced results markedly superior to those obtained using force-field methods. The experimental equilibrium structure of Si(8)O(12)H(8) has also been determined, demonstrating the use of empirical potentials rather than DFT methods when such potentials exist. We highlight the one major deficiency associated with classical MD-the absence of quantum effects-which causes some light-atom bonded-pair amplitudes of vibration to be significantly underestimated. However, using C(3)N(3)Cl(3) and C(3)N(3)H(3) as examples, we show that path-integral MD simulations can overcome these problems. The distance corrections and amplitudes of vibration obtained for C(3)N(3)Cl(3) are almost identical to those obtained from force-field methods, as we would expect for such a rigid molecule. In the case of C(3)N(3)H(3), for which an accurate experimental structure exists, the use of path-integral methods more than doubles the C-H amplitude of vibration.

Dynamic Laser Speckle Imaging of Cerebral Blood Flow

Optics Express. Aug, 2009  |  Pubmed ID: 19654798

Laser speckle imaging (LSI) based on the speckle contrast analysis is a simple and robust technique for imaging of heterogeneous dynamics. LSI finds frequent application for dynamical mapping of cerebral blood flow, as it features high spatial and temporal resolution. However, the quantitative interpretation of the acquired data is not straightforward for the common case of a speckle field formed by both by moving and localized scatterers such as blood cells and bone or tissue. Here we present a novel processing scheme, we call dynamic laser speckle imaging (dLSI), that can be used to correctly extract the temporal correlation parameters from the speckle contrast measured in the presence of a static or slow-evolving background. The static light contribution is derived from the measurements by cross-correlating sequential speckle images. In-vivo speckle imaging experiments performed in the rodent brain demonstrate that dLSI leads to improved results. The cerebral hemodynamic response observed through the thinned and intact skull are more pronounced in the dLSI images as compared to the standard speckle contrast analysis. The proposed method also yields benefits with respect to the quality of the speckle images by suppressing contributions of non-uniformly distributed specular reflections.

[Approach for the Recovery of Coronary Blood Flow by the Patients with Acute Myocardial Infarction]

Voenno-medit͡sinskiĭ Zhurnal. May, 2009  |  Pubmed ID: 19663209

A Wearable Diffuse Reflectance Sensor for Continuous Monitoring of Cutaneous Blood Content

Physics in Medicine and Biology. Sep, 2009  |  Pubmed ID: 19687533

An optical diffuse reflectance sensor for characterization of cutaneous blood content and optimized for continuous monitoring has been developed as part of a non-invasive multisensor system for glucose monitoring. A Monte Carlo simulation of the light propagation in the multilayered skin model has been performed in order to estimate the optimal geometrical separation of the light source and detector for skin and underlying tissue. We have observed that the pathlength within the upper vascular plexus of the skin which defines the sensor sensitivity initially grows with increasing source-detector distance (SDD) before reaching a maximum at 3.5 mm and starts to decay with further increase. At the same time, for distances above 2.4 mm, the sensor becomes sensitive to muscle blood content, which decreases the specificity to skin perfusion monitoring. Thus, the SDDs in the range from 1.5 mm to 2.4 mm satisfy the requirements of sensor sensitivity and specificity. The hardware implementation of the system has been realized and tested in laboratory experiments with a venous occlusion procedure and in an outpatient clinical study in 16 patients with type 1 diabetes mellitus. For both testing procedures, the optical sensor demonstrated high sensitivity to perfusion change provoking events. The general build-up of cutaneous blood under the sensor has been observed which can be associated with pressure-induced vasodilation as a response to the sensor application.

[Evolution of Gene Orders in Mycoplasmas (Bacteria, Firmicutes, Mollicutes)]

Genetika. Jul, 2009  |  Pubmed ID: 19705739

Quantitative methods of estimation of similarity between gene orders have been used to compare the genomes of 14 strains of mycoplasmas and 2 strains of phytoplasmas, i.e., all genomes of bacteria of the class Mollicutes deciphered to date. Reconstructions of the mycoplasma phylogeny based on comparisons of (a) gene orders in a chromosome and (b) nucleotide or amino acid sequences have proved to be almost identical, which confirms that quantitative measures of gene order similarity can be used for meaningful phylogenetic reconstructions. Genomic rearrangements have been almost equally frequent in the evolutions of three main groups of mycoplasmas. A gene order changes by 1% approximately every 7 Myr or less (the calculation is based on the assumption that a 1% change in the nucleotide sequence of the 16S rRNA gene requires, on average, 50 Myr). In contrast to another analyzed group of obligately parasitic bacteria (rickettsiae), no distinct tendency towards a decrease in the rate of genomic rearrangements has been found in the evolution of mycoplasmas.

Observation of Reaction Intermediates and Kinetic Mistakes in a Remarkably Slow Self-assembly Reaction

Chemical Communications (Cambridge, England). Oct, 2009  |  Pubmed ID: 19753372

Several intermediates and oligomeric mistakes in a metal-ligand self-assembly reaction are identified by 1H NMR, MALDI-MS, and XRD, providing evidence in support of multiple pathways in the "free-for-all" self-assembly process.

[Evolution of Gene Orders in Genomes of Cyanobacteria]

Genetika. Aug, 2009  |  Pubmed ID: 19769292

Genomes of 23 strains of cyanobacteria were comparatively analyzed using quantitative methods of estimation of gene order similarity. It has been found that reconstructions of phylogenesis of cyanobacteria based on the comparison of the orders of genes in chromosomes and nucleotide sequences appear to be similar. This confirms the applicability of quantitative measures of similarity of gene orders for phylogenetic reconstructions. In the evolution of marine unicellular plankton cyanobacteria, genome rearrangements are fixed with a low rate (about 3% of gene order changes per 1% of 16S rRNA changes), whereas in other groups of cyanobacteria the gene order can change several times more rapidly. The gene orders in genomes of cyanobacteria and chloroplasts preserve a considerable degree of similarity. The closest relatives of chloroplasts among the analyzed cyanobacteria are likely to be strains from hot springs belonging to the genus Synechococcus. Comparative analysis of gene orders and nucleotide sequences strongly suggests that Synechococcus strains from diferent environments (sea, fresh waters, hot springs) are not related and belong to evolutionally distant lines.

Thiadiazole-containing Expanded Heteroazaporphyrinoids: a Gas-phase Electron Diffraction and Computational Structural Study

Physical Chemistry Chemical Physics : PCCP. Oct, 2009  |  Pubmed ID: 19774289

The gas-phase molecular structure of a thiadiazole-containing expanded heteroazaporphyrinoid (C42H39N15S3) has been studied by a synchronous gas electron diffraction and mass spectrometric experiment and density functional theory calculations using the B3LYP hybrid method and cc-pVTZ basis sets. The molecule has an equilibrium structure of C3h symmetry with a planar macrocycle and the thiadiazole rings oriented in such a way that the sulfur atoms point outwards from the inner cavity. The unsubstituted macrocycle (C30H15N15S3) has been studied by DFT computations. An algorithm for building a complete set of internal coordinates, used in the computation of vibrational corrections, is also described.

Turbulent Transfer of Energy by Radiating Pulses

Physical Review Letters. Aug, 2009  |  Pubmed ID: 19792648

We propose a new mechanism for turbulent transport in systems which support radiating nonlinear solitary wave packets or pulses. The direct energy cascade is provided by adiabatically evolving pulses, whose widths and carrier wavelengths decrease. The inverse cascade is due to the excitation of radiation. The spectrum is steeper than the Kolmogorov-Zakharov spectrum of wave turbulence.

Preferential Growth of Single-walled Carbon Nanotubes with Metallic Conductivity

Science (New York, N.Y.). Oct, 2009  |  Pubmed ID: 19797656

Single-walled carbon nanotubes can be classified as either metallic or semiconducting, depending on their conductivity, which is determined by their chirality. Existing synthesis methods cannot controllably grow nanotubes with a specific type of conductivity. By varying the noble gas ambient during thermal annealing of the catalyst, and in combination with oxidative and reductive species, we altered the fraction of tubes with metallic conductivity from one-third of the population to a maximum of 91%. In situ transmission electron microscopy studies reveal that this variation leads to differences in both morphology and coarsening behavior of the nanoparticles that we used to nucleate nanotubes. These catalyst rearrangements demonstrate that there are correlations between catalyst morphology and resulting nanotube electronic structure and indicate that chiral-selective growth may be possible.

The Vesicle Cycle in Motor Nerve Endings of the Mouse Diaphragm

Neuroscience and Behavioral Physiology. Mar, 2009  |  Pubmed ID: 19234803

Experiments on the mouse diaphragm muscle using intracellular microelectrode recordings and fluorescence microscopy were performed to study the dynamics of transmitter secretion and synaptic vesicle recycling processes (the exocytosis-endocytosis cycle) in motor nerve endings (NE) during prolonged rhythmic stimulation (20 impulses/sec). During stimulation, there were triphasic changes in the amplitude of endplate potentials (EPP): an initial rapid reduction, followed by prolonged (1-2 min) stabilization of amplitude, i.e., a plateau, and then a further slow decrease. Restoration of EPP amplitude after stimulation for 3 min occurred over a period of several seconds. Loading of synaptic vesicles with the fluorescent endocytic stain FM1-43 showed that rhythmic stimulation led to a gradual (over 5-6 min) decrease in NE fluorescence, demonstrating exocytosis of synaptic vesicles. Quantum analysis of the electrophysiological data and comparison of these data with results from fluorescence studies suggested that mouse NE have a high rate of endocytosis and reutilization of synaptic vesicles (the mean recycling time was about 50 sec), which may support the maintenance of reliable synaptic transmission during prolonged high-frequency activity. The sizes of the release-ready and recycling pools of synaptic vesicles were determined quantitatively. It is suggested that vesicle recycling in mouse NE occurs via a short, rapid pathway with incorporation into the recycling pool. Vesicles of the reserve pool are not used for transmitter secretion in the stimulation conditions used here.

Aqueous Coordination Chemistry of H2: Why is Coordinated H2 Inert to Substitution by Water in Trans-Ru(P2)2(H2)H+-type Complexes (P2 = a Chelating Phosphine)?

Inorganic Chemistry. Apr, 2009  |  Pubmed ID: 19253994

The reactivity of a series of trans-Ru(P(2))(2)Cl(2) complexes with H(2) was explored. The complexes reacted with H(2) via a stepwise H(2) addition/heterolysis pathway to form the trans-[Ru(P(2))(2)(H(2))H](+) dihydrogen complexes. Some of the resulting eta(2)-H(2) complexes were surprisingly inert to substitution by water, even at concentrations as high as 55 M; however, the identity of the bidentate phosphine ligand greatly influenced the lability of the coordinated eta(2)-H(2) ligand. With less electron-donating phosphine ligands, the H(2) ligand was susceptible to substitution by H(2)O, whereas with more electron-rich phosphine ligands, the H(2) ligand was inert to substitution by water. Density functional theory (DFT) calculations of the ligand substitution reactions showed that the Ru-H(2) and Ru-H(2)O complexes are very close in energy, and therefore slight changes in the donor properties of the bidentate phosphine ligand can inhibit or promote the substitution of H(2)O for H(2).

Orientational Dynamics of the Compressible Nematic Liquid Crystals Induced by a Temperature Gradient

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Jan, 2009  |  Pubmed ID: 19257053

We have carried out a numerical study of a system of hydrodynamic equations including director reorientation, fluid flow, temperature, and density redistribution across a compressible hybrid-oriented liquid crystal (HOLC) cell under the influence of a temperature gradient nablaT directed normal to the restricting surfaces, when the sample is heated both from below and above. Calculations show that under the influence of nablaT the compressible HOLC sample settles down to a stationary flow regime, both with the horizontal u and vertical w components of velocity v, and u is directed in the opposite direction, approximately one order of magnitude less, than the one in the case of an incompressible HOLC cell. The role of hydrodynamic flow in the relaxation processes of the stress tensor components, for a number of dynamic regimes in the compressible HOLC cell containing 4-n-pentyl-4'-cyanobiphenyl, has been investigated.

Introgression As a Likely Cause of MtDNA Paraphyly in Two Allopatric Skippers (Lepidoptera: Hesperiidae)

Heredity. Jun, 2009  |  Pubmed ID: 19293835

Gene transfer between species during interspecific hybridization is a widely accepted reality in plants but is considered a relatively rare phenomenon among animals. Here we describe a unique case of mitochondrial DNA (mtDNA) paraphyly in the skipper genus, Erynnis, that involves well-diverged allopatric species. Using molecular evidence from both mitochondrial and nuclear genomes, we found high levels of intraspecific divergence in the mitochondrial genome within E. propertius (over 4% pair-wise sequence divergence) but no such differentiation in the nuclear genome. Sequence comparisons with related Erynnis suggest that past, but recent and infrequent introgression between E. propertius and E. horatius is the most reasonable explanation for the observed pattern of mtDNA paraphyly. This example of putative introgression highlights the complexity of mtDNA evolution and suggests that similar processes could be operating in other taxa that have not been extensively sampled. Our observations reinforce the importance of involving multiple genes with different modes of inheritance in the analysis of population history of congeneric taxa.

Synthesis and Crystallization of Infinite Indium and Gallium Acetate 1D Chain Structures and Concomitant Ethyl Acetate Hydrolysis

Inorganic Chemistry. Apr, 2009  |  Pubmed ID: 19320471

Two unusual complexes of formula [M(mu-OH)(mu-O(2)CCH(3))(2)](n) [M = In (1) or Ga (2)] were crystallized by diffusion of ethyl acetate into methanolic solutions of the M(NO(3))(3) salts and N-nitrosopyrrolidine. They represent the first examples of such simple group 13 containing structures comprising 1D chains, and their formation results from the surprising hydrolysis of ethyl acetate to provide the bridging acetate ligands.

[Synchronization in a Model of Interacting Inferior Olive Cells with Variable Electrotonic Coupling]

Biofizika. Jan-Feb, 2009  |  Pubmed ID: 19334632

Synchronization processes have been studied within the framework of a model describing the dynamics of two inferior olive cells coupled electrotonically through gap junctions surrounded by synaptic inhibitory terminals that block these couplings. A simple model of a chemical synaptic terminal based on the first-order kinetics has been constructed to describe the coupling break. It was found that different types of synchronous behavior exist in the system, depending on the parameters. These are 1:1 and 1:2 synchronization regimes, spike time binding, and others. It was demonstrated that even small changes in the coupling parameters (coupling strength and coupling break delay) may significantly affect the synchronous regimes of interacting cells. In some cases, the activity of one of inferior olive cells is suppressed due to collective dynamics, whereas the activity of the other cell is conserved.

Self-assembled Growth, Microstructure, and Field-emission High-performance of Ultrathin Diamond Nanorods

ACS Nano. Apr, 2009  |  Pubmed ID: 19344150

We report the growth of ultrathin diamond nanorods (DNRs) by a microwave plasma assisted chemical vapor deposition method using a mixture gas of nitrogen and methane. DNRs have a diameter as thin as 2.1 nm, which is not only smaller than reported one-dimensional diamond nanostructures (4-300 nm) but also smaller than the theoretical value for energetically stable DNRs. The ultrathin DNR is encapsulated in tapered carbon nanotubes (CNTs) with an orientation relation of (111)diamond//(0002)graphite. Together with diamond nanoclusters and multilayer graphene nanowires/nano-onions, DNRs are self-assembled into isolated electron-emitting spherules and exhibit a low-threshold, high current-density (flat panel display threshold: 10 mA/cm2 at 2.9 V/microm) field emission performance, better than that of all other conventional (Mo and Si tips, etc.) and popular nanostructural (ZnO nanostructure and nanodiamond, etc.) field emitters except for oriented CNTs. The forming mechanism of DNRs is suggested based on a heterogeneous self-catalytic vapor-solid process. This novel DNRs-based integrated nanostructure has not only a theoretical significance but also has a potential for use as low-power cold cathodes.

[About Erythropoietin Production in Humans from Different Age Groups]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Feb, 2009  |  Pubmed ID: 19368309

Erythropoietin level was studied in blood plasma of humans from different age groups and in patients with chronic hearts failure of ishemic genesis. It was determined that there was no statistically significant difference of erythropoietin level among the age groups. Erythropoietin level in patients with chronic heart failure was 16-fold greater (102.86 +/- 29.04 mU/ml) than in the studied elder aged groups (6.38 +/- 1.82 mU/ml). The data obtained indicate that elderly (60 to 85 years) persons' organisms retain the ability of response to hypoxia by intensive erythropoietin production.

[Erythropoietin Possible Influence on the Cellular Renovation Processes of Exocervical Epithelium in Norm, in Case of Chronic Cervicitis and Cervical Intraepithelial Neoplasia 1 and 2]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Feb, 2009  |  Pubmed ID: 19368312

The blood plasma erythropoietin content, erythropoietin content, erythropoietin and cellular renovation markers expression in exocervical epithelium in reproductive aged women with normal peripheral red blood values were studied. It was determined that erythropoietin expression increased in exocervical epithelium activity (cervical intraepithelial neoplasia 1 and 2), combined with the increase of blood plasma erythropoietin level, activation of pro- and antiapoptosis programs and cellular proliferation processes in cervical epithelium.

Ex Situ N and P Doping of Vertical Epitaxial Short Silicon Nanowires by Ion Implantation

Nanotechnology. Apr, 2009  |  Pubmed ID: 19420579

Vertical epitaxial short (200-300 nm long) silicon nanowires (Si NWs) grown by molecular beam epitaxy on Si(111) substrates were separately doped p- and n-type ex situ by implanting with B, P and As ions respectively at room temperature. Multi-energy implantations were used for each case, with fluences of the order of 10(13)-10(14) cm(-2), and the NWs were subsequently annealed by rapid thermal annealing (RTA). Transmission electron microscopy showed no residual defect in the volume of the NWs. Electrical measurements of single NWs with a Pt/Ir tip inside a scanning electron microscope (SEM) showed significant increase of electrical conductivity of the implanted NWs compared to that of a nominally undoped NW. The p-type, i.e. B-implanted, NWs showed the conductivity expected from the intended doping level. However, the n-type NWs, i.e. P- and As-implanted ones, showed one to two orders of magnitude lower conductivity. We think that a stronger surface depletion is mainly responsible for this behavior of the n-type NWs.

The Structure of Oxotitanium Phthalocyanine: a Gas-phase Electron Diffraction and Computational Study

Physical Chemistry Chemical Physics : PCCP. May, 2009  |  Pubmed ID: 19421550

The gas-phase molecular structure of oxotitanium phthalocyanine (TiOPc) has been studied by a synchronous gas electron diffraction and mass spectrometric experiment, and density functional theory calculations using the B3LYP hybrid method and cc-pVTZ basis sets. The molecule has an equilibrium structure of C4v symmetry with a convex macrocycle. The titanium atom is out-of-the-plane of the four central nitrogen atoms and forms a square pyramid with them, with the following parameters: r(Ti-N)=2.090(5) A, r(NN)=2.813(9) A (the side of the pyramid base), z(Ti)-z(N)=0.614 A (the height of the pyramid). Compared to solid-state crystal structures, the Ti-O distance in gas-phase TiOPc is shortened and the Ti-N distance is elongated, which can be attributed to significant intermolecular interaction in the crystals.

Exposure and Toxicity of Green Tea Polyphenols in Fasted and Non-fasted Dogs

Toxicology. Jun, 2009  |  Pubmed ID: 19464566

Standardized green tea extract was evaluated for exposure and toxicity in Beagle dogs following oral dosing by capsules. The main component (-)-epigallocatechin gallate (EGCG) accounted for 56-72% of the material. A 9-month chronic study (0, 200, 500, and 1000 mg/kg/day) was done in fasted dogs to take advantage of the reported improved catechin bioavailability with fasting. Extensive morbidity, mortality, and pathology of many major organs led to its early termination at 6.5 months and prevented identification of the toxicity mechanisms. A follow-up 13-week study examined the exposure to and toxicity of the extract. In general, toxicities were less severe than in the chronic study during the same interval. Dosing in a fed state resulted in considerably lower and less variable exposure than found under fasted conditions. Toxicity was less frequent and of lesser severity with lower exposure but limited sample size and large variability prevented reaching that definitive conclusion. Differences in mortality and morbidity between the preliminary terminated chronic and follow-up subchronic studies with the same dose of the same drug lot and similar exposure were not fully resolved as there may be other as yet unclear confounding factors.

[Erythropoietin in Patients with Chronic Heart Failure]

Klinicheskaia Meditsina. 2009  |  Pubmed ID: 19469252

The aim of this work was to elucidate the relationship between the serum erythropoietin level, the degree of heart involvement in patients with chronic cardiac failure (CCF), characteristics of peripheral red blood cells and iron metabolism. A total of 77 patients with ischemic CCF were enrolled in the study. The control group comprised 13 subjects free from cardiovascular disorders. The analyses encompassed peripheral blood, serum iron, iron-binding capacity of serum, creatinine clearance, erythropoietin and TNF-alpha levels, echoCG data. The patients with CCF were divided into three groups based on the level of erythropoietin. Statistical analysis revealed the relationship between anemia, structural-functional changes in myocardium and erythropoietin production. Anemia appeared to be an additional stimulus for biosynthesis of erythropoietin in these patients.

[Influence of Drosophila Melanogaster Genotype on Biological Effects of Endocymbiont Wolbachia (stamm WMelPop)]

Tsitologiia. 2009  |  Pubmed ID: 19505052

Comparative analyses of symbiotic bacteria Wolbachia (stamm wMelPop reducing lifespan of flies) morphology in normal and mutant strains of Drosophila melanogaster as well as the influence of Wolbachia on the host cell ultrastructure have been done. Wolbachia infected D. melanogaster mutation strains Trithorax-like -- Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ have been received by special flies crossing. Uninfected strain D. melanogaster white-1118 (w1118) have been obtained by antibiotic treatment of initially infected strain D. melanogaster [w]w1118. Complex of different methods and approaches let to investigate for the first time the morphology of cell structure before and after bacterial infection of insects and to value the bacterial presence effect on flies viability and reproduction of normal and mutant flies. Morphology af cytoplasmic compartments in early embryos and eggs layed by infected and uninfecyed females Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ have been analyzed. Electron microscopy has shown that D. melanogaster embryos contain typical Wolbachia contacting with different host organelles that verify preservation of their functional activity. Atificial mitochondria and Wolbachia (wMelPop) of unusual morphology with defective bacterial membranes have been visualised in D. melanogaster [w]Trl362/TM3, Sb1 Ser y+. Wolbachia presence in ovarium cells from strains [w]Trl362/TM3, Sb1 Ser y+ and [w]Trlen82/TM3, Sb1 Ser y+ did not influence on eggs quantity layed by females. We have demonstrated for the first time that lifespan of infected and uninfected strains: D. melanogaster Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ were similar. However the lifespan of imago from strain [w]w1118 was lower in comparison to those from strains Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+. It suggests that either chromosomal balancer TM3 or Trl mutation play an importance role in host-symbiotic relationship. Next experiments have revealed that lifespan of homozygotic flies decreased essentially and was close to lifespan of strain [w]w1118. Data obtained confirm that chromosomal balancer TM3 can affect on symbiont-host relationship.

Ordering of the Nanoscale Step Morphology As a Mechanism for Droplet Self-propulsion

Nano Letters. Jul, 2009  |  Pubmed ID: 19507835

We establish a new mechanism for self-propelled motion of droplets, in which ordering of the nanoscale step morphology by sublimation beneath the droplets themselves acts to drive them perpendicular and up the surface steps. The mechanism is demonstrated and explored for Ga droplets on GaP(111)B, using several experimental techniques allowing studies of the structure and dynamics from micrometers to the atomic scale. We argue that the simple assumptions underlying the propulsion mechanism make it relevant for a wide variety of materials systems.

Precursors to Dinitrogen Reduction: Structures and Reactivity of Trans-[Fe(DMeOPrPE)2(eta(2)-H2)H]+ and Trans-[Fe(DMeOPrPE)2(N2)H]+

Dalton Transactions (Cambridge, England : 2003). Nov, 2009  |  Pubmed ID: 20449203

trans-[Fe(DMeOPrPE)(2)(H(2))H](+) and trans-[Fe(DMeOPrPE)(2)(N(2))H](+) (DMeOPrPE = 1,2-bis(dimethoxypropylphosphino)ethane) were synthesized and their structures determined by X-ray crystallography. These complexes are important species in a dinitrogen reduction scheme involving protonation of an iron(0) dinitrogen complex to produce ammonia. The rates of substitution of the coordinated H(2) and N(2) molecules with acetonitrile were monitored in a variety of organic solvents. The coordinated N(2) substituted approximately 6 times faster than H(2), but surprisingly the solvent had little effect on the observed rates. The results suggest that the H(2) molecule in trans-[Fe(DMeOPrPE)(2)(H(2))H](+) does not participate in hydrogen bonding to the bulk solvent, as was previously observed in the analogous Ru complex. The deprotonation of trans-[Fe(DMeOPrPE)(2)(N(2))H](+) to yield Fe(DMeOPrPE)(2)N(2) was investigated in the presence of a variety of anions, and it was found that the anion facilitates the reaction through an ion-pairing interaction in which the anion removes electron density from the hydride ligand.

Expression of AKR1C3 in Renal Cell Carcinoma, Papillary Urothelial Carcinoma, and Wilms' Tumor

International Journal of Clinical and Experimental Pathology. 2009  |  Pubmed ID: 20126582

Human aldo-keto reductase (AKR) 1C3 is a monomeric cytoplasmic multifunctional enzyme that reduces ketosteroids, ketoprostaglandins, and lipid aldehydes. AKR1C3 was initially identified as an enzyme involved in steroid metabolism. However, immunohistochemistry has demonstrated AKR1C3 in normal adult kidneys with expression in Bowman' capsule, the mesangial cells, proximal and distal tubules, as well as mature urothelial epithelium. The significance of its spatial distribution and metabolic activities in the kidney remains undefined. In addition to its ability to catalyze steroid hormones (including androgen, desoxycorticosterone, and progesterone) and involvement in prostaglandins metabolism, we suspect that AKR1C3 may function as a chemical barrier in the renal tubules for normal function in mature kidneys. Moreover, AKR1C3 may represent a developmental marker for some urological epithelial tissues. In this study, we demonstrate widespread expression of AKR1C3 in renal neoplasms with a phenotype recapitulating mature kidney (i.e., renal cell carcinoma) and urothelium also known as transitional epithelium (i.e., papillary urothelial carcinoma), but noted limited AKR1C3 expression in renal neoplasms with a phenotype recapitulating embryonic kidneys (i.e., Wilms' tumor). Our results suggest that AKR1C3 may represent a developmental marker that is related to renal epithelium maturity.

QNA-based 'Star Track' QSAR Approach

SAR and QSAR in Environmental Research. Oct, 2009  |  Pubmed ID: 20024804

In the existing quantitative structure-activity relationship (QSAR) methods any molecule is represented as a single point in a many-dimensional space of molecular descriptors. We propose a new QSAR approach based on Quantitative Neighbourhoods of Atoms (QNA) descriptors, which characterize each atom of a molecule and depend on the whole molecule structure. In the 'Star Track' methodology any molecule is represented as a set of points in a two-dimensional space of QNA descriptors. With our new method the estimate of the target property of a chemical compound is calculated as the average value of the function of QNA descriptors in the points of the atoms of a molecule in QNA descriptor space. Substantially, we propose the use of only two descriptors rather than more than 3000 molecular descriptors that apply in the QSAR method. On the basis of this approach we have developed the computer program GUSAR and compared it with several widely used QSAR methods including CoMFA, CoMSIA, Golpe/GRID, HQSAR and others, using ten data sets representing various chemical series and diverse types of biological activity. We show that in the majority of cases the accuracy and predictivity of GUSAR models appears to be better than those for the reference QSAR methods. High predictive ability and robustness of GUSAR are also shown in the leave-20%-out cross-validation procedure.

In Silico Method for Identification of Promising Anticancer Drug Targets

SAR and QSAR in Environmental Research. Oct, 2009  |  Pubmed ID: 20024808

In recent years, the accumulation of the genomics, proteomics, transcriptomics data for topological and functional organization of regulatory networks in a cell has provided the possibility of identifying the potential targets involved in pathological processes and of selecting the most promising targets for future drug development. We propose an approach for anticancer drug target identification, which, using microarray data, allows discrete modelling of regulatory network behaviour. The effect of drugs inhibiting a particular protein or a combination of proteins in a regulatory network is analysed by simulation of a blockade of single nodes or their combinations. The method was applied to the four groups of breast cancer, HER2/neu-positive breast carcinomas, ductal carcinoma, invasive ductal carcinoma and/or a nodal metastasis, and to generalized breast cancer. As a result, some promising specific molecular targets and their combinations were identified. Inhibitors of some identified targets are known as potential drugs for therapy of malignant diseases; for some other targets we identified hits in the commercially available sample databases.

Trans-Bis(acetonitrile-κN)bis-{1,2-bis-[bis-(3-hydroxy-prop-yl)phosphino]ethane-κP,P'}iron(II) Dichloride

Acta Crystallographica. Section E, Structure Reports Online. 2009  |  Pubmed ID: 21582706

In the title compound, [Fe(CH(3)CN)(2)(C(14)H(32)O(4)P(2))(2)]Cl(2), the Fe(II) atom lies on a crystallographic inversion center and has a distorted trans-FeN(2)P(4) octa-hedral coordination environment arising from two P,P'-bidentate 1,2-bis-[bis-(3-hydroxy-prop-yl)phosphino]ethane ligands in the equatorial plane and two acetonitrile mol-ecules in the axial positions. One of the pendant -(CH(2))(3)OH groups of the ligand is disordered over two sets of sites in a 0.597 (5):0.403 (5) ratio. In the crystal, O-H⋯Cl and O-H⋯O hydrogen bonding helps to establish the packing.

DNA Barcoding Central Asian Butterflies: Increasing Geographical Dimension Does Not Significantly Reduce the Success of Species Identification

Molecular Ecology Resources. Sep, 2009  |  Pubmed ID: 21564901

DNA barcoding employs short, standardized gene regions (5' segment of mitochondrial cytochrome oxidase subunit I for animals) as an internal tag to enable species identification. Prior studies have indicated that it performs this task well, because interspecific variation at cytochrome oxidase subunit I is typically much greater than intraspecific variation. However, most previous studies have focused on local faunas only, and critics have suggested two reasons why barcoding should be less effective in species identification when the geographical coverage is expanded. They suggested that many recently diverged taxa will be excluded from local analyses because they are allopatric. Second, intraspecific variation may be seriously underestimated by local studies, because geographical variation in the barcode region is not considered. In this paper, we analyse how adding a geographical dimension affects barcode resolution, examining 353 butterfly species from Central Asia. Despite predictions, we found that geographically separated and recently diverged allopatric species did not show, on average, less sequence differentiation than recently diverged sympatric taxa. Although expanded geographical coverage did substantially increase intraspecific variation reducing the barcoding gap between species, this did not decrease species identification using neighbour-joining clustering. The inclusion of additional populations increased the number of paraphyletic entities, but did not impede species-level identification, because paraphyletic species were separated from their monophyletic relatives by substantial sequence divergence. Thus, this study demonstrates that DNA barcoding remains an effective identification tool even when taxa are sampled from a large geographical area.

Tetra-carbonyl-bis(η-cyclo-penta-dienyl)bis[(dec-9-en-1-yl)diphenyl-phosphine]dimolybdenum(0)(Mo-Mo) Tetra-hydro-furan Disolvate

Acta Crystallographica. Section E, Structure Reports Online. 2009  |  Pubmed ID: 21578585

The asymmetric unit of the title compound, [Mo(2)(η(5)-C(5)H(5))(2)(C(22)H(29)P)(2)(CO)(4)]·2C(4)H(8)O, contains two half-mol-ecules of the organometallic species and two solvent mol-ecules. Both organometallic mol-ecules are completed by crystallographic inversion symmetry, yielding dimeric units with Mo-Mo single-bond lengths of 3.2703 (6) and 3.2548 (6) Å. Each Mo atom is also coordinated by an η(5)-cyclo-pentdienyl ligand, two carbonyl ligands, and a (dec-9-en-1-yl)diphenyl-phosphine ligand.

Bis{1,2-bis-[bis-(3-hydroxy-prop-yl)phosphino]ethane}dichloridoiron(II)

Acta Crystallographica. Section E, Structure Reports Online. 2010  |  Pubmed ID: 21579318

In the title compound, [FeCl(2)(C(14)H(32)O(4)P(2))(2)], the Fe(II) atom (site symmetry ) adopts a distorted trans-FeCl(2)P(4) octa-hedral geometry with two P,P'-bidentate ligands in the equatorial positions and two chloride ions in the axial positions. In the crystal, mol-ecules are linked by O-H⋯O and O-H⋯Cl hydrogen bonds, generating a three-dimensional network.

Trans-Bis{1,2-bis-[bis-(2-methoxy-ethyl)phosphino]ethane}dichloridoiron(II)

Acta Crystallographica. Section E, Structure Reports Online. 2010  |  Pubmed ID: 21580210

The Fe atom in the title compound, [FeCl(2)(C(14)H(32)O(4)P(2))(2)], has a distorted octa-hedral coordination with four P atoms in equatorial positions and two Cl atoms in apical positions.

Mobility of BtuB and OmpF in the Escherichia Coli Outer Membrane: Implications for Dynamic Formation of a Translocon Complex

Biophysical Journal. Dec, 2010  |  Pubmed ID: 21156129

Diffusion of two Escherichia coli outer membrane proteins-the cobalamin (vitamin B12) receptor (BtuB) and the OmpF porin, which are implicated in the cellular import pathways of colicins and phages-was measured in vivo. The lateral mobility of these proteins is relevant to the mechanism of formation of the translocon for cellular import of colicins such as the rRNase colicin E3. The diffusion coefficient (D) of BtuB, the primary colicin receptor, complexed to fluorescent antibody or colicin, is 0.05±0.01 μm2/s and 0.10±0.02 μm2/s, respectively, over a timescale of 25-150 ms. Mutagenesis of the BtuB TonB box, which eliminates or significantly weakens the interaction between BtuB and the TonB energy-transducing protein that is anchored in the cytoplasmic membrane, resulted in a fivefold larger value of D, 0.27±0.06 μm2/s for antibody-labeled BtuB, indicating a cytoskeletal-like interaction of TonB with BtuB. OmpF has a diffusion coefficient of 0.006±0.002 μm2/s, ∼10-fold smaller than that of BtuB, and is restricted within a domain of diameter 100 nm, showing it to be relatively immobile compared to BtuB. Thus, formation of the outer membrane translocon for cellular import of the nuclease colicins is a demonstrably dynamic process, because it depends on lateral diffusion of BtuB and collisional interaction with relatively immobile OmpF.

[Infusion Therapy in Patients with Cholelithiasis Complicated by Obstructive Jaundice]

Khirurgiia. 2010  |  Pubmed ID: 21370589

[Vinpotropil in the Treatment of Dyscirculatory Encephalopathy with Cognitive Impairment Without Dementia]

Zhurnal Nevrologii I Psikhiatrii Imeni S.S. Korsakova / Ministerstvo Zdravookhraneniia I Meditsinskoĭ Promyshlennosti Rossiĭskoĭ Federatsii, Vserossiĭskoe Obshchestvo Nevrologov [i] Vserossiĭskoe Obshchestvo Psikhiatrov. 2010  |  Pubmed ID: 21183916

The fixed combination containing 5 mg of vinpocetine and 400 mg of pyracetam (vinpotropil) was prescribed to 349 patients with dyscirculatory encephalopathy, I-II stages in dose one capsule three times a day during 3 months. After this treatment, repeated neuropsychological testing showed significant diminishing of dysexecutive cognitive impairment linked with frontal lobes dysfunction. The cognitive improvement was associated with the regress of subjective neurological symptoms like headache, dizziness, tinnitus, fatigue and insomnia. Vinpotropil was safe and well tolerated in elderly patients with chronic cerebral vascular insufficiency.

Orthologs of Meiotic Proteins in Prokaryotic Proteomes

Doklady. Biochemistry and Biophysics. Nov-Dec, 2010  |  Pubmed ID: 21184305

Origin and Post-glacial Dispersal of Mitochondrial DNA Haplogroups C and D in Northern Asia

PloS One. 2010  |  Pubmed ID: 21203537

More than a half of the northern Asian pool of human mitochondrial DNA (mtDNA) is fragmented into a number of subclades of haplogroups C and D, two of the most frequent haplogroups throughout northern, eastern, central Asia and America. While there has been considerable recent progress in studying mitochondrial variation in eastern Asia and America at the complete genome resolution, little comparable data is available for regions such as southern Siberia--the area where most of northern Asian haplogroups, including C and D, likely diversified. This gap in our knowledge causes a serious barrier for progress in understanding the demographic pre-history of northern Eurasia in general. Here we describe the phylogeography of haplogroups C and D in the populations of northern and eastern Asia. We have analyzed 770 samples from haplogroups C and D (174 and 596, respectively) at high resolution, including 182 novel complete mtDNA sequences representing haplogroups C and D (83 and 99, respectively). The present-day variation of haplogroups C and D suggests that these mtDNA clades expanded before the Last Glacial Maximum (LGM), with their oldest lineages being present in the eastern Asia. Unlike in eastern Asia, most of the northern Asian variants of haplogroups C and D began the expansion after the LGM, thus pointing to post-glacial re-colonization of northern Asia. Our results show that both haplogroups were involved in migrations, from eastern Asia and southern Siberia to eastern and northeastern Europe, likely during the middle Holocene.

Transition Entropy, Helmholtz Free Energy, and Heat Capacity of Free-standing Smectic Films Above the Bulk Smectic-A-isotropic Transition Temperature: a Mean-field Treatment

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Oct, 2010  |  Pubmed ID: 21230292

We have carried out a numerical study of both the structural and thermodynamic properties of free-standing smectic films (FSSFs) for two cases of enhanced pair interactions in the bounding layers. Calculations, based upon the extended McMillan's approach with anisotropic forces, shows a stepwise reduction of the value of the heat capacity as the temperature is raised above the bulk smectic A-isotropic transition. The effects of surface "enhanced" pair interactions in the bounding layers and of film thickness on the orientational and translational order parameters, the Helmholtz free energy, and entropy of FSSFs have also been investigated. Reasonable agreement between the theoretically predicted and the experimentally obtained--by means of calorimetric techniques--data on the heat capacity of the partially fluorinated 5-n-alkyl-2-(4-n-(perfluoroalkyl-metheleneoxy)phenyl) (H10F5MOPP) films has been obtained.

[Location of Genes in Chromosomes: Random or Not?]

Genetika. Oct, 2010  |  Pubmed ID: 21254548

The possibility is discussed that the order of genes in chromosomes is not random but determined by natural selection, i.e., is a selectively valuable character. Cases of long-term conservation of gene linkage or synteny in evolution are presented. Examples and possible mechanisms of nonrandom gene localization in prokaryotic and eukaryotic chromosomes are considered.

[Genetic Polymorphism of Microbotryum Violaceum S. I. Isolates Collected from Different Plant Species on the Territory of Russia]

Genetika. Nov, 2010  |  Pubmed ID: 21261069

The present-day studies in the field of systematics and phylogeny of microorganisms, fungi, in particular, are characterized by a wide use of new approaches and methods of molecular biology. The use of a diversity of genetic markers permits a distinct differentiation of closely related species into individual evolutionary independent lines. It is shown in this work that all Microbotryum violaceum s. l. isolates studied by us are divided into five evolutionary groups according to the host plant.

[Erythropoietin Levels in Human Tear Fluid]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Nov, 2010  |  Pubmed ID: 21427970

Erythropoietin level was evaluated in blood plasma and tear fluid of humans with normal functions of eye and normal blood characteristics. We examined 21 patients. Principle ability of erythropoietin level detection in patient's tear fluid ascertained.

[Dynamic Changes of Erythropoietin and Tumor Necrosis Factor-alpha Levels in Peripheral Blood and Their Correlation with Erythropoiesis Changes in Posttransfusion Polycythemia in Animals]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Nov, 2010  |  Pubmed ID: 21427973

Posttransfusion polyglobulia reveals elevated level of the tumor necrosis factor-alpha in peripheral blood, suppresses erythropoiesis in bone marrow erythroblastic islands by diminishing the newly forming erythroblastic islands, and suppresses erythropoietin production in rats.

2,2'-(Propane-2,2-di-yl)dibenzothia-zole

Acta Crystallographica. Section E, Structure Reports Online. 2010  |  Pubmed ID: 21587514

The two symmetry-independent mol-ecules in the asymmetric unit of the title compound, C(17)H(14)N(2)S(2), have similar geometry; the dihedral angles between the least-squares planes of the benzothia-zole groups in the two mol-ecules are 83.93 (3) and 81.26 (3)°.

A Mouse Model of Lethal Synergism Between Influenza Virus and Haemophilus Influenzae

The American Journal of Pathology. Feb, 2010  |  Pubmed ID: 20042666

Secondary bacterial infections that follow infection with influenza virus result in considerable morbidity and mortality in young children, the elderly, and immunocompromised individuals and may also significantly increase mortality in normal healthy adults during influenza pandemics. We herein describe a mouse model for investigating the interaction between influenza virus and the bacterium Haemophilus influenzae. Sequential infection with sublethal doses of influenza and H. influenzae resulted in synergy between the two pathogens and caused mortality in immunocompetent adult wild-type mice. Lethality was dependent on the interval between administration of the bacteria and virus, and bacterial growth was prolonged in the lungs of dual-infected mice, although influenza virus titers were unaffected. Dual infection induced severe damage to the airway epithelium and confluent pneumonia, similar to that observed in victims of the 1918 global influenza pandemic. Increased bronchial epithelial cell death was observed as early as 1 day after bacterial inoculation in the dual-infected mice. Studies using knockout mice indicated that lethality occurs via a mechanism that is not dependent on Fas, CCR2, CXCR3, interleukin-6, tumor necrosis factor, or Toll-like receptor-4 and does not require T or B cells. This model suggests that infection with virulent strains of influenza may predispose even immunocompetent individuals to severe illness on secondary infection with H. influenzae by a mechanism that involves innate immunity, but does not require tumor necrosis factor, interleukin-6, or signaling via Toll-like receptor-4.

The Microrheology of Sickle Hemoglobin Gels

Biophysical Journal. Aug, 2010  |  Pubmed ID: 20712998

Sickle cell disease is a rheological disease, yet no quantitative rheological data exist on microscopic samples at physiological concentrations. We have developed a novel method for measuring the microrheology of sickle hemoglobin gels, based on magnetically driven compression of 5- to 8-microm-thick emulsions containing hemoglobin droplets approximately 80 microm in diameter. Using our method, by observing the expansion of the droplet area as the emulsion is compressed, we were able to resolve changes in thickness of a few nanometers with temporal resolution of milliseconds. Gels were formed at various initial concentrations and temperatures and with different internal domain structure. All behaved as Hookean springs with Young's modulus from 300 to 1500 kPa for gels with polymerized hemoglobin concentration from 6 g/dl to 12 g/dl. For uniform, multidomain gels, Young's modulus mainly depended on the terminal concentration of the gel rather than the conditions of formation. A simple model reproduced the quadratic dependence of the Young's modulus on the concentration of polymerized hemoglobin. Partially desaturated samples also displayed quadratic concentration dependence but with a smaller proportionality coefficient, as did samples that were desaturated in steps; such samples were significantly less rigid than gels formed all at once. The magnitude of the Young's modulus provides quantitative support for the dominant models of sickle pathophysiology.

Phylogeography of the Y-chromosome Haplogroup C in Northern Eurasia

Annals of Human Genetics. Nov, 2010  |  Pubmed ID: 20726964

To reconstruct the phylogenetic structure of Y-chromosome haplogroup (hg) C in populations of northern Eurasia, we have analyzed the diversity of microsatellite (STR) loci in a total sample of 413 males from 18 ethnic groups of Siberia, Eastern Asia and Eastern Europe. Analysis of SNP markers revealed that all Y-chromosomes studied belong to hg C3 and its subhaplogroups C3c and C3d, although some populations (such as Mongols and Koryaks) demonstrate a relatively high input (more than 30%) of yet unidentified C3* haplotypes. Median joining network analysis of STR haplotypes demonstrates that Y-chromosome gene pools of populations studied are characterized by the presence of DNA clusters originating from a limited number of frequent founder haplotypes. These are subhaplogroup C3d characteristic for Mongolic-speaking populations, "star cluster" in C3* paragroup, and a set of DYS19 duplicated C3c Y-chromosomes. All these DNA clusters show relatively recent coalescent times (less than 3000 years), so it is probable that founder effects, including social selection resulting in high male fertility associated with a limited number of paternal lineages, may explain the observed distribution of hg C3 lineages.

Graphene Synthesis on Cubic SiC/Si Wafers. Perspectives for Mass Production of Graphene-based Electronic Devices

Nano Letters. Mar, 2010  |  Pubmed ID: 20141155

The outstanding properties of graphene, a single graphite layer, render it a top candidate for substituting silicon in future electronic devices. The so far exploited synthesis approaches, however, require conditions typically achieved in specialized laboratories and result in graphene sheets whose electronic properties are often altered by interactions with substrate materials. The development of graphene-based technologies requires an economical fabrication method compatible with mass production. Here we demonstrate for the fist time the feasibility of graphene synthesis on commercially available cubic SiC/Si substrates of >300 mm in diameter, which result in graphene flakes electronically decoupled from the substrate. After optimization of the preparation procedure, the proposed synthesis method can represent a further big step toward graphene-based electronic technologies.

Thermal and Flexoelectric Effects on Nematodynamics in a Microvolume Cylindrical Cavity

The Journal of Chemical Physics. Mar, 2010  |  Pubmed ID: 20210410

We have considered a homogeneously aligned liquid crystal (HALC) microvolume, confined between two infinitely long horizontal coaxial cylinders subjected to both a temperature gradient nabla T and radially applied electric field E. We have investigated dynamic field pumping, i.e., studied the interaction between director, velocity, electric fields, as well as, a radially applied temperature gradient, where the inner cylinder is kept at a lower temperature than the outer one. Flexoelectric polarization P has been taken into account as well, and modeled via the classical Meyer treatment. In order to elucidate the role of nabla T, E, and P in producing hydrodynamic flow, we have carried out a numerical study of a system of hydrodynamic equations including director reorientation, fluid flow, and temperature redistribution across the HALC cavity. Calculations show that there exists a range of parameter values (voltage and curvature of the inner cylinder) producing a kinklike orientation process in the system, as well as a nonstandard pumping regime with maximum flow near the hot cylinder.

Hydrogen Storage by Boron-nitrogen Heterocycles: a Simple Route for Spent Fuel Regeneration

Journal of the American Chemical Society. Mar, 2010  |  Pubmed ID: 20214402

We describe a new hydrogen storage platform based on well-defined BN heterocyle materials. Specifically, we demonstrate that regeneration of the spent fuel back to the charged fuel can be accomplished using molecular H(2) and H(-)/H(+) sources. Crystallographic characterization of intermediates along the regeneration pathway confirms our structural assignments and reveals unique bonding changes associated with increasing hydrogen content on boron and nitrogen. Synthetic access to the fully charged BN cyclohexane fuels will now enable investigations of these materials in hydrogen desorption studies.

Spontaneous Symmetry Breaking During Interrupted Crystallization of an Axially Chiral Amino Acid Derivative

Chemical Communications (Cambridge, England). Mar, 2010  |  Pubmed ID: 20221503

High net enantiomeric excess was observed for crystal collections obtained by crystallization of the TFA salt of a configurationally stable yet racemic axially chiral amidoamine in EtOH solution with or without stirring (up to >99% ee at < or = 15% crystallization).

Asymptotic Evaluation of the Pulse Train Radiated by an Angled Beam and Fluid Coupled Rectangular Ultrasonic Transducer

The Journal of the Acoustical Society of America. Mar, 2010  |  Pubmed ID: 20329826

The near field underneath the ultrasonic probe fluid coupled to an isotropic solid is approximated in the frequency domain by a closed form asymptotic solution. The approximation is based on the problem decomposition and uses the stationary phase method evaluating the response to an equivalent surface source. This results in a sum of contributions, each dominating in a specific geometrical region, the main beam or a side lobe. The transitional zones are also described. The pulse trains are computed using the harmonic synthesis and compared with the results obtained by direct calculation of Fourier integrals. It is shown that the asymptotic approach permits us to elucidate the physics of problem and leads to a numerical algorithm which is about 10(4) times faster than the direct computations.

Divergent Syntheses of Copper-indium Bimetallic Single-source Precursors Via Thiolate Ligand Exchange

Inorganic Chemistry. Jun, 2010  |  Pubmed ID: 20459100

Several copper-indium bimetallic single-source precursors (SSPs 2-9) have been prepared efficiently by exchange reactions of (Ph(3)P)(2)CuIn(SEt)(4) (1) with protic ligands. This divergent approach has been successfully applied on multigram scales to produce nearly quantitative yields of known and newly reported SSPs. The former group features the previously difficult target (Ph(3)P)(2)CuIn(SePh)(4) (2), and the latter includes (Ph(3)P)(2)CuIn(SEt)(2)(SePh)(2) (3), the first SSP to incorporate both sulfur and selenium within a single copper-indium bimetallic complex.

The Transition Between Conformal Atomic Layer Epitaxy and Nanowire Growth

Journal of the American Chemical Society. Jun, 2010  |  Pubmed ID: 20469861

Conformal atomic layer deposition of thin Sb(2)S(3) layers takes place epitaxially on suitable substrates at 90 degrees C. More elevated deposition temperatures increase the mobility of the solid and result in the diffusion of Sb(2)S(3) along surface energy gradients. On an Sb(2)Se(3) wire that presents the high-energy c facet at its extremity, this results in the axial elongation of the wire with a Sb(2)S(3) segment. When an Sb(2)S(3) wire whose c planes are exposed on the sides is used as the substrate, the homoepitaxy collects material laterally and yields a nano-object with a rectangular cross section.

Multimodal Study of Secondary Interactions in Cp*Ir Complexes of Imidazolylphosphines Bearing an NH Group

Journal of the American Chemical Society. Jun, 2010  |  Pubmed ID: 20486707

Hydrogen bonding phenomena are explored using a combination of X-ray diffraction, NMR and IR spectroscopy, and DFT calculations. Three imidazolylphosphines R(2)PImH (ImH = imidazol-2-yl, R = t-butyl, i-propyl, phenyl, 1a-1c) and control phosphine (i-Pr)(2)PhP (1d) lacking an imidazole were used to make a series of complexes of the form Cp*Ir(L(1))(L(2))(phosphine). In addition, in order to suppress intermolecular interactions with either imidazole nitrogen, 1e, a di(isopropyl)imidazolyl analogue of 1b was made along with its doubly (15)N-labeled isotopomer to explore bonding interactions at each imidazole nitrogen. A modest enhancement of transfer hydrogenation rate was seen when an imidazolylphosphine ligand 1b was used. Dichloro complexes (L(1) = L(2) = Cl, 2a-2c,2e) showed intramolecular hydrogen bonding as revealed by four X-ray structures and various NMR and IR data. Significantly, hydride chloride complexes [L(1) = H, L(2) = Cl, 3a-3c and 3e-((15)N)(2)] showed stronger hydrogen bonding to chloride than hydride, though the solid-state structure of 3b evinced intramolecular Ir-H...H-N bonding reinforced by intermolecular N...H-N bonding between unhindered imidazoles. These results are compared to literature examples, which show variations in preferred hydrogen bonding to hydride, halide, CO, and NO ligands. Surprising differences were seen between the dichloro complex 2b with isopropyl groups on phosphorus, which appeared to exist as a mixture of two conformers, and related complex 2a with tert-butyl groups on phosphorus, which exists in chlorinated solvents as a mixture of conformer 2a-endo and chelate 5a-Cl, the product of ionization of one chloride ligand. This difference became apparent only through a series of experiments, especially (15)N chemical shift data from 2D (1)H-(15)N correlation. The results highlight the difficulty of characterizing hemilabile, bifunctional complexes and the importance of innocent ligand substituents in determining structure and dynamics.

Functional Classification of Proteins Based on Projection of Amino Acid Sequences: Application for Prediction of Protein Kinase Substrates

BMC Bioinformatics. 2010  |  Pubmed ID: 20537135

The knowledge about proteins with specific interaction capacity to the protein partners is very important for the modeling of cell signaling networks. However, the experimentally-derived data are sufficiently not complete for the reconstruction of signaling pathways. This problem can be solved by the network enrichment with predicted protein interactions. The previously published in silico method PAAS was applied for prediction of interactions between protein kinases and their substrates.

Nonmechanical Pumping Principle in Submicrosized Devices

The Journal of Chemical Physics. Jun, 2010  |  Pubmed ID: 20550418

Dynamic field pumping principle has been developed utilizing the interactions of both the director and velocity fields and temperature-redistribution across a two-dimensional (2D) homogeneously aligned liquid crystal (HALC) film under the influence both of a heat flow directed normal to the upper bounding surface, whereas on the lower bounding surface, the temperature is kept constant, and the normally directed electric field, due to electric double layers, i.e., a shielding layers that is naturally created within the liquid crystal (LC) near a charged surfaces. Calculations, based on the nonlinear extension of the classical Ericksen-Leslie theory, shows that the HALC material under the influence of the heat flow start moving in the horizontal direction. After turning off the heat flow, the HALC drop settles down to the rest, and the temperature field across the LC film is finally downfall to the value of temperature on the lower bounding surface. The role of hydrodynamic flow in the relaxation processes of the temperature field to its equilibrium distribution across the 2D HALC film, containing 4-n-pentyl-4(')-cyanobiphenyl, has been investigated for a number of dynamic regimes.

Synthesis and Structural Characterization of a Fused Bispyrone and Preparation of the First Metal Bispyrylium Complexes

Chemical Communications (Cambridge, England). Aug, 2010  |  Pubmed ID: 20567791

Dehydroacetic acid reacts with acetic anhydride in the presence of perchloric acid to give a salt which upon careful neutralization affords a fused bis-gamma-pyrone. The bis-gamma-pyrone forms stable metal complexes with Li, Mg, Cu(II), Ni(II), Zn, Fe(II), Co(II) and Ba perchlorates whose crystal structures reveal that the ligand possesses significant bispyrylium character while the metal is coordinated at the negatively charged edge of the structure.

Three's Company: Co-crystallization of a Self-assembled S(4) Metallacyclophane with Two Diastereomeric Metallacycle Intermediates

Chemical Communications (Cambridge, England). May, 2010  |  Pubmed ID: 20582349

Three discrete supramolecular self-assembled arsenic(iii) complexes including an unusual S(4)-symmetric tetranuclear [As(4)L(2)Cl(4)] metallacyclophane and two diastereomeric cis/trans-[As(2)LCl(2)] metallacycle intermediates co-crystallize within a single crystal lattice.

[Correlations of Sister Chromatids Cohesion Complexes Distribution with Histones H3 and H4 Modifications]

Tsitologiia. 2010  |  Pubmed ID: 20586273

The formulation of "histone code" theory brings active investigations of the role of histone modifications and other supramolecular factors of DNA condensation in transcription regulation. In this work, we have analyzed the localization of methylated histones on 9, 36 and 79 lysines, hyperacetylated H4 histone, and subunits of cohesion complex DRAD21 relatively of Drosophila melanogaster polytene chromosomes chromatin condensation. We propose the hypotheses of a cascade regulation of transcription activity defined by histone modifications and the adaptive role of sister chromatids cohesion in the transcription of high active and extensive genes.

Noise in Laser Speckle Correlation and Imaging Techniques

Optics Express. Jul, 2010  |  Pubmed ID: 20639937

We study the noise of the intensity variance and of the intensity correlation and structure functions measured in light scattering from a random medium in the case when these quantities are obtained by averaging over a finite number N of pixels of a digital camera. We show that the noise scales as 1/N in all cases and that it is sensitive to correlations of signals corresponding to adjacent pixels as well as to the effective time averaging (due to the finite integration time) and spatial averaging (due to the finite pixel size). Our results provide a guide to estimation of noise levels in such applications as multi-speckle dynamic light scattering, time-resolved correlation spectroscopy, speckle visibility spectroscopy, laser speckle imaging etc.

Suppressed Expression of Type 2 3alpha/type 5 17beta-hydroxysteroid Dehydrogenase (AKR1C3) in Endometrial Hyperplasia and Carcinoma

International Journal of Clinical and Experimental Pathology. 2010  |  Pubmed ID: 20661409

The diagnosis of endometrial hyperplasia and endometrial type adenocarcinoma arising within the uterine cavity has long been rested on morphologic criteria. Although distinction between normal endometrial epithelium from adenocarcinoma is usually straightforward, the separation between normal and hyperplastic endometrium, particularly those cases without atypia, can be a diagnostic challenge. The same is true in separation of hyperplastic endometrium with atypia from endometrial-type endometrial adenocarcinoma. Type 2 3alpha-/type 5 17beta-hydroxysteroid dehydrogenase (HSD) (AKR1C3) is a multifunctional enzyme involved in androgen, estrogen, progesterone, and pros-taglandin metabolism. Its expression has been shown in the epithelium of the renal tubules, urothelial epithelium, and endothelial cells in normal tissues as well as in prostatic adenocarcinoma. The proliferation and maintenance of endometrial epithelium is dependent on both estrogen and progesterone; and AKR1C3-mediated steroid metabolism may play a critical role in the maintenance of viable normal and abnormal endometrial epithelium. We studied the expression of AKR1C3 in 33 endometrial biopsy specimens including 13 cases of normal proliferative endometrium, 8 cases of hyperplastic endometrium with and without atypia, and 12 cases of primary endometrial adenocarcinoma of endometrial type. We demonstrated a uniform, diffuse, and strong expression of AKR1C3 in normal endometrial epithelium but not in endometrial stromal cells. In contrast, the expression of AKR1C3 is reduced in both hyperplastic and carcinomatous endometrial epithelium. These findings suggest that AKR1C3 may play important roles in the physiology of endometrial cells and that suppressed AKR1C3 expression may represent a feature that allows differentiation of hyperplastic and neoplastic endometrial epithelium from normal endometrial epithelium. However, reduced AKR1C3 expression cannot distinguish hyperplastic endometrium from endometrial adenocarcinoma of endometrial type. The biologic and pathological roles of AKR1C3 in endometrial epithelium require further investigation.

Synthesis and Stabilization of a Monomeric Iron(II) Hydroxo Complex Via Intramolecular Hydrogen Bonding in the Secondary Coordination Sphere

Inorganic Chemistry. Oct, 2010  |  Pubmed ID: 20799715

Utilizing the pyridinediimine ligand [(2,6-(i)PrC(6)H(3))N═CMe)(N((i)Pr)(2)C(2)H(4))N═CMe)C(5)H(3)N] (didpa), the iron(II) complexes Fe(didpa)Br(2) (1), [Fe(Hdidpa)Br(2)][PF(6)] (2), and [Fe(Hdidpa)CH(3)CN(OH)][2PF(6)] (3) were synthesized and characterized by X-ray diffraction and spectroscopic methods. The X-ray data show that the didpa scaffold is capable of forming intramolecular hydrogen bonds in the solid state located within the secondary coordination sphere of complexes 2 and 3. These hydrogen bonds are responsible for stabilizing the iron(II) hydroxo ligand in 3, which originates from H(2)O.

Collaborative Development of Predictive Toxicology Applications

Journal of Cheminformatics. 2010  |  Pubmed ID: 20807436

OpenTox provides an interoperable, standards-based Framework for the support of predictive toxicology data management, algorithms, modelling, validation and reporting. It is relevant to satisfying the chemical safety assessment requirements of the REACH legislation as it supports access to experimental data, (Quantitative) Structure-Activity Relationship models, and toxicological information through an integrating platform that adheres to regulatory requirements and OECD validation principles. Initial research defined the essential components of the Framework including the approach to data access, schema and management, use of controlled vocabularies and ontologies, architecture, web service and communications protocols, and selection and integration of algorithms for predictive modelling. OpenTox provides end-user oriented tools to non-computational specialists, risk assessors, and toxicological experts in addition to Application Programming Interfaces (APIs) for developers of new applications. OpenTox actively supports public standards for data representation, interfaces, vocabularies and ontologies, Open Source approaches to core platform components, and community-based collaboration approaches, so as to progress system interoperability goals.The OpenTox Framework includes APIs and services for compounds, datasets, features, algorithms, models, ontologies, tasks, validation, and reporting which may be combined into multiple applications satisfying a variety of different user needs. OpenTox applications are based on a set of distributed, interoperable OpenTox API-compliant REST web services. The OpenTox approach to ontology allows for efficient mapping of complementary data coming from different datasets into a unifying structure having a shared terminology and representation.Two initial OpenTox applications are presented as an illustration of the potential impact of OpenTox for high-quality and consistent structure-activity relationship modelling of REACH-relevant endpoints: ToxPredict which predicts and reports on toxicities for endpoints for an input chemical structure, and ToxCreate which builds and validates a predictive toxicity model based on an input toxicology dataset. Because of the extensible nature of the standardised Framework design, barriers of interoperability between applications and content are removed, as the user may combine data, models and validation from multiple sources in a dependable and time-effective way.

1,2-Azaborine Cations

Angewandte Chemie (International Ed. in English). Oct, 2010  |  Pubmed ID: 20821788

[Percutaneous Coronary Interventions in Patients with Acute Myocardial Infarction After Successful Thrombolysis]

Kardiologiia. 2010  |  Pubmed ID: 20831040

In 259 patients with acute myocardial infarction admitted to N.V. Sklifosofsky Institute of Urgent Aid in 2003-20007 we compared efficacy of 3 strategies of treatment after successful thrombolytic therapy (TLT): percutaneous coronary intervention (PCI) because of recurrent ischemia within 5 days after thrombolytic therapy (n = 66), PCI in patients with elevated risk of death according to TIMI during 12-24 hours after TLT (n = 26); conservative treatment after TLT (n = 167). Differences at comparison of two invasive strategies were related to the state of infarct-related artery and clinical effect. The use of PCI in patients with elevated risk of death in 12-24 hours after TLT was in all cases associated with timely provision of completed reperfusion, improvement of contractility, prevention of development of left ventricular aneurism. The use of both invasive strategies allowed to lessen rate of complications, and achieve several fold lowering of mortality. The data obtained show that for more objective and timely selection of patients for PCI after effective TLT it is expedient to use quantitative estimation of risk according to TIMI. Such approach allows without waiting for ischemia recurrence to detect patients with elevated risk and critical stenoses being in acute need of combined reperfusion.

A Colorimetric Proton Sponge

The Journal of Organic Chemistry. Oct, 2010  |  Pubmed ID: 20857948

1,8-Bis(dimethylamino)naphthalene ("Proton Sponge") and bromomaleic anhydride react quickly at room temperature, generating 3-(4,5-bis(dimethylamino)napthalen-1-yl)furan-2,5-dione (4-maleicanhydridoproton sponge or "MAPS"). MAPS is a deep purple solid that exhibits positive solvatochromism in solution. It is a weaker base than Proton Sponge. When protonated in solution, MAPS loses its color, but the color change can be reversed by deprotonation with a stronger base. MAPS thus acts as a colorimetric version of a proton sponge.

Photoluminescence from Silicon Nanoparticles Embedded in Ammonium Silicon Hexafluoride

Nanotechnology. Oct, 2010  |  Pubmed ID: 20876982

Silicon (Si) nanoparticles (NPs) were synthesized by transforming a Si wafer surface to ammonium silicon hexafluoride (ASH) or (NH(4))(2)SiF(6) under acid vapor treatment. Si-NPs which were found to be embedded within the polycrystalline (ASH) layer exhibit a strong green-orange photoluminescence (PL). Differential PL measurements revealed a major double component spectrum consisting of a broad band associated with the ASH-Si wafer interfacial porous oxide layer and a high energy band attributable to Si-NPs embedded in the ASH. The origin of the latter emission can be explained in terms of quantum/spatial confinement effects probably mediated by oxygen related defects in or around Si-NPs. Although Si-NPs are derived from the interface they are much smaller in size than those embedded within the interfacial porous oxide layer (SiO(x), x > 1.5). Transmission electron microscopy (TEM) combined with Raman scattering and Fourier transformed infrared (FTIR) analysis confirmed the presence of Si-NP and Si-O bondings pointing to the role of oxygen related defects in a porous/amorphous structure. The presence of oxygen of up to 4.5 at.% in the (NH(4))(2)SiF(6) layer was confirmed by energy dispersive spectroscopy (EDS) analysis.

Self-assembled E(2)L(3) Cryptands (E = P, As, Sb, Bi): Transmetalation, Homo- and Heterometallic Assemblies, and Conformational Isomerism

Inorganic Chemistry. Nov, 2010  |  Pubmed ID: 20919726

A series of Group 15-containing homometallic (E(2)L(3), E = P, As, Sb, Bi) and heterometallic (AsSbL(3), AsBiL(3), PSbL(3)) supramolecular cryptands were prepared by the self-assembly of pnictogen halides with dithiolate ligand or by direct transmetalation from a heavier congener. Structural characterization by single crystal X-ray diffraction shows that the E-S bond distances and S-E-S bond angles are significantly affected by the identity of the pnictogen. (1)H NMR spectroscopy reveals that the homometallic cryptands are dynamic in solution: surprisingly one ligand "flips", perturbing the C(3) symmetry of the complex and giving a new asymmetric conformer. Density functional theory calculations were carried out on both the symmetric and the asymmetric conformations of the cryptands, and the energies were compared to those observed by NMR spectroscopy. It was found that the relative stability of the asymmetric cryptand to its symmetric conformer increases with increasing size of the Group 15 element. Finally, it is reported that if two metals are present during the self-assembly process, heterometallic cryptands form. These supramolecular cryptands are reminiscent of their organic analogues, but result from a self-assembly process rather than a stepwise synthesis. Surprisingly, they possess conformational isomerism and exhibit dynamic transmetalation in their reactivity which provides access to otherwise unattainable assemblies.

On the Influence of Strain on Ion Transport: Microstructure and Ionic Conductivity of Nanoscale YSZ|Sc2O3 Multilayers

Physical Chemistry Chemical Physics : PCCP. Nov, 2010  |  Pubmed ID: 20938560

Multilayer samples of the type (YSZ|Sc2O3) × n with layer thicknesses between 8 nm (n=100) and 250 nm (n=5) were prepared on (0001) sapphire substrates by pulsed laser deposition (PLD). The samples were characterised using X-ray diffraction (XRD), scanning electron microscopy (HRSEM) and transmission electron microscopy (TEM/HRTEM, SAED (selected-area electron diffraction) and quantitative EELS (electron energy-loss spectroscopy)). The polycrystalline layers show a columnar microstructure, which is typical for the used preparation technique. The layers are highly textured and only one axial orientation relation is found between yttria-stabilised zirconia (YSZ), scandium oxide and the substrate: (0001) Al2O3‖(111) Sc2O3‖(111) YSZ. A preferred orientation relationship also exists for the azimuthal rotation of the crystallites, which was demonstrated by SAED, XRD pole figure measurements and fast Fourier transformation (FFT) of HRTEM micrographs. The interfaces between YSZ, Sc2O3 and the substrate are sharp and do not contain diffuse transition regions. Dislocations appear not to be arranged in regular arrays. With increasing interface density (thinner individual layers in the multilayer), the conductivity of the multilayers decreases. We relate this to the negative nominal misfit present at the YSZ|Sc2O3 interfaces (compressive stress in YSZ at the phase boundaries). This observation agrees well with the previously investigated case of YSZ|Y2O3 (A. Peters et al., Phys. Chem. Chem. Phys., 2008, 10, 4623), where tensile misfit strain was present in YSZ at the phase boundaries, leading to a conductivity increase.

Growth Mechanism of Self-catalyzed Group III-V Nanowires

Nano Letters. Nov, 2010  |  Pubmed ID: 20939507

Group III-V nanowires offer the exciting possibility of epitaxial growth on a wide variety of substrates, most importantly silicon. To ensure compatibility with Si technology, catalyst-free growth schemes are of particular relevance, to avoid impurities from the catalysts. While this type of growth is well-documented and some aspects are described, no detailed understanding of the nucleation and the growth mechanism has been developed. By combining a series of growth experiments using metal-organic vapor phase epitaxy, as well as detailed in situ surface imaging and spectroscopy, we gain deeper insight into nucleation and growth of self-seeded III-V nanowires. By this mechanism most work available in literature concerning this field can be described.

[Possible Fundamental Unity of Magnetobiological "resonances"]

Biofizika. Jul-Aug, 2010  |  Pubmed ID: 20968073

Organisms exposed to a combination of weak, parallel directed static and alternate magnetic fields show a distinct response when the frequency of the alternate component is formally equal to the cyclotron frequencies for Ca2+ or other biologically important ions. It is impossible to explain the observable phenomenon through a magnetoinduced drift of the ions, as the Lorentz's force is too small to change ionic movements. In similar conditions, a resonance-like response arises when the alternate field is tuned to the Larmor frequency for nuclear-spin magnetic moments. The mechanism of these phenomena is also still unclear. In the report, the arguments are presented to treat both types of effects in a single context for which the existence of ion magnetic dipoles is postulated.

[Quality of Life in Women with Small Pelvic Varicosity]

Angiologii͡a I Sosudistai͡a Khirurgii͡a = Angiology and Vascular Surgery. 2010  |  Pubmed ID: 21032873

We surveyed a total of one hundred and ninety women presenting with small pelvic varicose veins (SPVIV). The chronic pelvic pain syndrome (CPPS) was revealed in nearly a quarter of the examined patients (24.7 %). The women's quality of life was assessed using the SF-36 questionnaire as a more integrative parameter, having demonstrated that women presenting with SPVV had a substantial decrease in all the components of both physical health and mental well-being. The obtained findings have strongly suggested the necessity of carrying out secondary prevention in women suffering from SPVV, even if there are no clinically pronounced manifestations of the disease.

Magnetic Diagnostics for Equilibrium Reconstructions in the Presence of Nonaxisymmetric Eddy Current Distributions in Tokamaks (invited)

The Review of Scientific Instruments. Oct, 2010  |  Pubmed ID: 21033979

The lithium tokamak experiment (LTX) is a modest-sized spherical tokamak (R(0)=0.4 m and a=0.26 m) designed to investigate the low-recycling lithium wall operating regime for magnetically confined plasmas. LTX will reach this regime through a lithium-coated shell internal to the vacuum vessel, conformal to the plasma last-closed-flux surface, and heated to 300-400 °C. This structure is highly conductive and not axisymmetric. The three-dimensional nature of the shell causes the eddy currents and magnetic fields to be three-dimensional as well. In order to analyze the plasma equilibrium in the presence of three-dimensional eddy currents, an extensive array of unique magnetic diagnostics has been implemented. Sensors are designed to survive high temperatures and incidental contact with lithium and provide data on toroidal asymmetries as well as full coverage of the poloidal cross-section. The magnetic array has been utilized to determine the effects of nonaxisymmetric eddy currents and to model the start-up phase of LTX. Measurements from the magnetic array, coupled with two-dimensional field component modeling, have allowed a suitable field null and initial plasma current to be produced. For full magnetic reconstructions, a three-dimensional electromagnetic model of the vacuum vessel and shell is under development.

Electrophilic Aromatic Substitution of a BN Indole

Journal of the American Chemical Society. Nov, 2010  |  Pubmed ID: 21043508

We report the first examples of a "BN-fused" indole, and we demonstrate that this new family of unnatural indole derivatives undergoes electrophilic aromatic substitution (EAS) reactions with the same regioselectivity as its organic analogue. Competition experiments reveal that N-t-Bu-BN-indole is more nucleophilic in EAS reactions than its carbonaceous counterpart. X-ray structural analysis between BN indole and classic indole highlights significant differences in bond distances, in particular for bonds associated with the boron atom.

[A Search for a "Genghis Khan Chromosome"]

Genetika. Sep, 2010  |  Pubmed ID: 21061634

Zerial et al. (2003) have shown that a special variant of the Y chromosome, characterized by a set of microsatellite markers occurs at high frequency in the number of human populations of Central Asia. This variant was attributed to the descendants of Genghis Khan and its accumulation, to social selection. A search of this Y chromosome variant in Russian populations was conducted. The "Genghis Khan Y chromosome" has been found among Altaians, Altai Kazakhs, Buryats, Kalmyks, Nogaits, and Tuvinians. Its highest frequency (13.8%) was observed in Nogaits. In the examined cases the carriers of the "Genghis Khan Y chromosome" possessed no information on their origin.

Photochemical Water Decomposition in the Troposphere: DFT Study with a Symmetrized Kohn-Sham Formalism

Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry. Dec, 2010  |  Pubmed ID: 21080398

Photochemical reaction of the electronically excited NO(2)* species with the water molecule is studied in terms of a new version of density functional theory by selecting the specific (2)A'' symmetry of the whole system, which is different from the ground-state pattern. The excited C(2)A(2) state of the NO(2) molecule is found to be distorted to the equilibrium structure O=N-O(.), which poses the (2)A'' symmetry in the C(s) point group. With the B3LYP functional it is shown that such an electronically excited NO(2)* molecule, generated by visible light (λ=420 nm), can react with water vapor to produce OH+HONO species, an important source of tropospheric hydroxyl radicals. This photochemical process can be considered as a possible mechanism of atmosphere self-cleaning.

Pharmacokinetic and Tissue Distribution Study of [14C]fluasterone in Male Beagle Dogs Following Intravenous, Oral and Subcutaneous Dosing Routes

Chemico-biological Interactions. Jan, 2010  |  Pubmed ID: 19836365

The purpose of this work was to compare the pharmacokinetics (PK) and tissue distribution of [14C]fluasterone following intravenous (iv), subcutaneous (sc) and oral (po) administration in male Beagle dogs. The main goal of the investigation was to discover if non-oral routes would alter parameters observed in this study following the administration of [14C]fluasterone. The oral formulation had a lower bioavailability (47%) compared to the sc formulation (84%). Po and sc administration resulted in a similar t(max); however, the observed C(max) following sc dosing was less than half of that after oral dosing. The sc route had the greatest overall exposure (AUC(0-infinity)). Tissue distribution analysis 2 h post-intravenous dosing showed that connective tissue (adipose and bone), liver, and skeletal muscle accumulated relatively high levels of fluasterone. The majority of the dose was retained during the first 24 h. Elimination of [14C]fluasterone-derived radioactivity following intravenous dosing resulted in urine and feces containing 7.6% and 28%, respectively, of the total dose over the first 24 h. Elimination of [14C]fluasterone-derived radioactivity following subcutaneous dosing resulted in 4.6% in urine and 7.8% in feces of the total dose over the first 24 h. Following oral dosing, elimination resulted in 3.8% in urine and 36% in feces over the first 24h. In conclusion, the sc route of administration offers some advantages to po and iv due to the prolonged release and increased retention through 24 h.

Cognitive Impairments in Progression of Parkinson's Disease

Neuroscience and Behavioral Physiology. Jan, 2010  |  Pubmed ID: 20012495

A total of 88 patients with progression of Parkinson's disease (PD) were studied. Cognitive impairments (CI) in PD were in most cases progressive in nature, predominantly because of increases in the severity of dysregulatory and neurodynamic disorders, impairments to visuospatial functions, and, in some cases, deficits in nominative speech function. A high frequency of transformation of moderate cognitive impairments to dementia was demonstrated over periods of 2-5 years. Predictors of the progression of CI in PD were identified: elderly age, later onset of disease, and the severity of PD. The greatest rate of progression of CI was seen in patients with initially more severe impairments of regulatory and visuospatial functions.

Full-field Optical Coherence Tomography for the Rapid Estimation of Epidermal Thickness: Study of Patients with Diabetes Mellitus Type 1

Physiological Measurement. Feb, 2010  |  Pubmed ID: 20016116

Changes in morphology of the skin are an important factor that can affect non-invasive measurements performed through this organ, in particular for glucose monitoring in e.g. patients with diabetes mellitus. A characterization technique for non-contact in vivo profiling of the superficial skin layers can be beneficial for evaluation of the performance of such measurement systems. We applied a full-field optical coherence tomography (OCT) system followed by the fully automatic processing for this task. With the developed procedure, non-invasive quantification of the skin morphology can be performed within a few minutes. The dorsal skin of the upper arm of 22 patients with Type 1 Diabetes Mellitus was investigated with an OCT system and with a commercially available dermatological laser scanning confocal microscope (CM) as a reference method. The estimates of epidermal thickness from OCT were compared with the results of expert-assisted analysis of confocal images. The highest correlation with the CM measurements has been obtained for the distance from the entrance peak to the first minimum of the OCT reflection profile (R2 = 0.657, p < 0.0001). In this specific patient group, we have observed a statistically significant correlation of the subjects' body mass index with the distance from the entrance peak to the dermal reflection peak in the OCT profile (p = 0.010). Furthermore, the same OCT parameter is negatively correlated with age with marginal statistical significance (p = 0.062). At the same time, no relation of diabetes-related parameters (duration of disease and concentration of glycated haemoglobin) to the skin morphology observed with the OCT and CM was found.

Stepwise Introduction of Thiolates in Copper-indium Binuclear Complexes

Inorganic Chemistry. May, 2010  |  Pubmed ID: 20373801

We report the synthesis and characterization of copper-indium binuclear I-III complexes composing the series (Ph(3)P)(2)CuIn(SEt)(x)Cl(4-x) (1-5; 0 < or = x < or = 4). Members of the series, which are prepared by variations in the stoichiometry, are compared in terms of their solid-state structures, spectroscopic features, and suitability as precursors for CuInS(2) materials. The regiochemistry of thiolate substitution, the preference for monomeric versus dimeric (eight-membered ring) structures, and new synthetic strategies informed by this series are all discussed.

L-NAME-induced Heavy Proteinuria in Healthy Rats

Doklady Biological Sciences : Proceedings of the Academy of Sciences of the USSR, Biological Sciences Sections / Translated from Russian. Jan-Feb, 2010  |  Pubmed ID: 20380173

Location of Modulatory Beta Subunits in BK Potassium Channels

The Journal of General Physiology. May, 2010  |  Pubmed ID: 20385746

Large-conductance voltage- and calcium-activated potassium (BK) channels contain four pore-forming alpha subunits and four modulatory beta subunits. From the extents of disulfide cross-linking in channels on the cell surface between cysteine (Cys) substituted for residues in the first turns in the membrane of the S0 transmembrane (TM) helix, unique to BK alpha, and of the voltage-sensing domain TM helices S1-S4, we infer that S0 is next to S3 and S4, but not to S1 and S2. Furthermore, of the two beta1 TM helices, TM2 is next to S0, and TM1 is next to TM2. Coexpression of alpha with two substituted Cys's, one in S0 and one in S2, and beta1 also with two substituted Cys's, one in TM1 and one in TM2, resulted in two alphas cross-linked by one beta. Thus, each beta lies between and can interact with the voltage-sensing domains of two adjacent alpha subunits.

Morphology of Neuropeptide CNP2 Modulation of Heart Activity in Terrestrial Snail

Peptides. Jul, 2010  |  Pubmed ID: 20399241

A family of neuropeptides called Command Neuron Peptides (CNPs) was described ten years ago as the protein products of the gene HCS2, specifically expressed in the identified interneurons of the nervous system of terrestrial snail (Helix lucorum L. and H. pomatia L.). Recently, the CNP-like peptides have been detected by immunochemistry and immunoblotting in nervous systems of representatives of different invertebrate phyla (Mollusca, Annelida, and Insecta). Still, the function of these peptides remains largely unknown. In Helix it is shown that CNPs: modulate the electrical activity of unidentified central neurons, modulate the pneumostome motoneurons, stimulate neural cones growth in neural cultures. Here, we describe for the first time the CNPs-immunoreactive neural fibers in walls of both auricle and ventricle of the snail heart. We show that application of the synthetic neuropeptide CNP2 (DYPRLamide) in perfusion saline affects heart rate and magnitude of beats in isolated snail heart. The results suggest that in Helix the Command Neuron Peptides could participate in neural modulation of cardiovascular system.

[A Two-compartment Phenomenological Model of a Dopaminergic Neuron]

Biofizika. Mar-Apr, 2010  |  Pubmed ID: 20429283

A two-compartment model of the dopaminergic neuron based on modified FitzHue-Nagumo oscillators for each compartment has been built. The compartments corresponded to the soma and dendrites and differed by the values of small parameters. The influence of stimuli (applied current for the somatic compartment and synaptic activation for the dendritic compartment) on the model has been studied. It has been shown that the activation of AMPA and NMDA synaptic currents lead to the generation of high-frequency bursts by the neuron. The mechanisms underlying the generation of the bursts have been investigated.

Assessment of Oral Toxicity and Safety of Pentamethylchromanol (PMCol), a Potential Chemopreventative Agent, in Rats and Dogs

Toxicology. Jun, 2010  |  Pubmed ID: 20430063

2,2,5,7,8-Pentamethyl-6-chromanol (PMCol) was administered by gavage in rats for 28 days at dose levels of 0, 100, 500, and 2000mg/kg/day. PMCol administration induced decreases in body weight gains and food consumption, hepatotoxicity (increased TBILI, ALB, ALT, TP; increased relative liver weights; increased T4 and TSH), nephrotoxicity (increased BUN and BUN/CREAT, histopathology lesions), effect on lipid metabolism (increased CHOL), anemia, increase in WBC counts (total and differential), coagulation (FBGN upward arrow and PT downward arrow) and hyperkeratosis of the nonglandular stomach in the 2000mg/kg/day dose group (in one or both sexes). In the 500mg/kg/day dose group, toxicity was seen to a lesser extent. In the 100mg/kg/day dose group, only increased CHOL (females) was observed. To assess the toxicity of PMCol in male dogs it was administered orally by capsule administration for 28 days at dose levels of 0, 50, 200 and 800mg/kg/day (four male dogs/dose group). PMCol treatment at 800mg/kg/day resulted in pronounced toxicity to the male dogs. Target organs of toxicity were liver and thymus. Treatment at 200mg/kg/day resulted in toxicity consistent with slight adverse effect on the liver only. The results of the safety pharmacology study indicate that doses of 0, 50, 200 and 800mg/kg administered orally did not have an effect on the QT interval, blood pressures and body temperatures following dosing over a 24-h recording period. Under the conditions of this study, the no-observed-adverse effect level (NOAEL) for daily oral administration of PMCol by gavage for 28 days to male rats was 100mg/kg/day and 50mg/kg in male dogs. In female rats, the NOAEL was not established due to statistically significant and biologically meaningful increases in CHOL level seen in the 100mg/kg/day dose group. The results of these studies indicated that administration of PMCol at higher dose levels resulted in severe toxicity in dogs and moderate toxicity in rats, however, administration at lower levels is considered to be less likely to result in toxicity following 28 days of exposure. Sex-related differences were seen in rats. Male rats appeared to have greater sensitivity to nephrotoxicity, while female animals had a greater incidence of hepatoxicity and changes in hematological parameters evaluated, especially at a dose of 500mg/kg/day, which correlated to the higher plasma drug levels in female rats. It appeared that dogs were generally more sensitive than rats to oral administration of PMCol. Further examination of the potential toxic effects of PMCol in longer term studies is required prior to understanding the full risks of PMCol administration as a chemopreventative agent.

The Gas-phase Structure of Octaphenyloctasilsesquioxane Si8O12Ph8 and the Crystal Structures of Si8O12(p-tolyl)8 and Si8O12(p-ClCH2C6H4)8

Dalton Transactions (Cambridge, England : 2003). Aug, 2010  |  Pubmed ID: 20440427

The equilibrium molecular structure of octaphenyloctasilsesquioxane Si(8)O(12)Ph(8) in the gas phase has been determined by electron diffraction. It was found to have D(4) point-group symmetry, with Si-O bond lengths of 1.634(15)-1.645(19) A, and a narrow range [147.5(45)-149.8(24) degrees] of Si-O-Si angles. The structures of Si(8)O(12)(p-tolyl)(8) and Si(8)O(12)(p-ClCH(2)C(6)H(4))(8) have been determined by X-ray diffraction and are found to have Si(8)O(12) cages significantly distorted from the symmetry found for Si(8)O(12)Ph(8) in the gas phase. Thus, Si-O-Si angles range between 144.2(2)-151.64(16) degrees for Si(8)O(12)(p-tolyl)(8), and between 138.8(2)-164.2(2) degrees for Si(8)O(12)(p-ClCH(2)C(6)H(4))(8). These three structures show how much a Si(8)O(12) cage may be distorted away from an ideal structure, free from intermolecular forces, by packing forces in a crystalline lattice.

Supramolecular "transmetalation" Leads to an Unusual Self-assembled P2L3 Cryptand

Angewandte Chemie (International Ed. in English). Feb, 2010  |  Pubmed ID: 20077454

Cutaneous Blood Perfusion As a Perturbing Factor for Noninvasive Glucose Monitoring

Diabetes Technology & Therapeutics. Jan, 2010  |  Pubmed ID: 20082580

It is widely accepted that noninvasive glucose monitoring (NIGM) has the potential to revolutionize diabetes therapy. However, current approaches to NIGM studied to date have not yet demonstrated a level of acceptable functionality to allow real-time use, beyond restricted fields of application. A number of reviews have been devoted to the subject of NIGM with different focuses related to challenges and a description of the respective underlying problems. This review is aimed at addressing a fundamental topic in the application of NIGM that seems to have received less attention, by describing the perturbations that result in a reduced functionality of NIGM in daily use. Here we provide a short general introduction to glucose monitoring and a basic illustration of the electromagnetic spectrum with a description of the respective physical mechanisms underlying the measurement techniques. This allows for a better understanding of how these perturbing factors affect the measured properties. Cutaneous blood perfusion is one of the major perturbing factors to NIGM, along with variations in temperature, migration of water, and the effect of attachment of the sensor to the skin. An understanding of the mechanisms underlying perfusion variation over time and within the measured human skin tissue matrix is required to enable a discrimination between glucose-induced effects within the tissue and various biophysical impacts to be made. It is suggested that a plurality of probing frequencies is required to discriminate glucose-related changes from the perturbations. A system designed to perform the measurements in different regions of the electromagnetic spectrum with dedicated sensors (multisensor approach) has the potential to more efficiently and reliably discriminate glucose-related information from perturbations. This can be achieved by combining signals related to measurements with different physical underlying mechanisms of the interaction between the probing field propagation and the tissue to help account for the different sources of perturbations.

BN Benzonitrile: an Electron-deficient 1,2-dihydro-1,2-azaborine Featuring Linkage Isomerism

Chemical Communications (Cambridge, England). Feb, 2010  |  Pubmed ID: 20087518

BN Benzonitrile 2, a 1,2-dihydro-1,2-azaborine bearing an electron-withdrawing boron substituent was prepared and characterized, and its coordination chemistry investigated; reactivity studies revealed that BN benzonitrile 2 undergoes BCN-BNC linkage isomerism upon coordination to Cr(CO)(5).

Oligomeric Structure of Brain Abundant Proteins GAP-43 and BASP1

Journal of Structural Biology. Jun, 2010  |  Pubmed ID: 20109554

Brain abundant proteins GAP-43 and BASP1 participate in the regulation of actin cytoskeleton dynamics in neuronal axon terminals. The proposed mechanism suggests that the proteins sequester phosphatidylinositol-4,5-diphosphate (PIP(2)) in the inner leaflet of the plasma membrane. We found that model anionic phospholipid membranes in the form of liposomes induce rapid oligomerization of GAP-43 and BASP1 proteins. Multiply charged phosphoinositides produced the most potent effect. Anionic detergent sodium dodecyl sulfate (SDS) at submicellar concentration stimulated formation of similar oligomers in solution. BASP1, but not GAP-43, also formed oligomers at sufficiently high concentration in the absence of lipids and SDS. Electron microscopy study demonstrated that the oligomers have disk-shaped or annular structure of 10-30nm in diameter. BASP1 also formed higher aggregates of linear rod-like structure, with average length of about 100nm. In outward appearance, the oligomers and linear aggregates are reminiscent of oligomers and protofibrils of amyloid proteins. Both the synthetic N-terminal peptide GAP-43(1-40) and the brain-derived fragment GAP-43-3 preserved the ability to oligomerize under the action of acidic phospholipids and SDS. On the contrary, BASP1 fragment truncated by the short N-terminal myristoylated peptide was unable to form oligomers. GAP-43 and BASP1 oligomerization can be regulated by calmodulin, which disrupts the oligomers and displaces the proteins from the membrane. We suggest that in vivo, the role of membrane-bound GAP-43 and BASP1 oligomers consists in accumulation of PIP(2) in functional clusters, which become accessible for other PIP(2)-binding proteins after dissociation of the oligomers.

The Effect of Blood Content on the Optical and Dielectric Skin Properties

Physiological Measurement. Jan, 2011  |  Pubmed ID: 21149928

A wearable system incorporating sensors for dielectric and optical spectroscopy was used to study skin properties and their dependence on the cutaneous blood content (CBC). Simultaneous measurements with both modalities were carried out on the upper arm during blood perfusion-provoking exercises performed by four subjects in four separate sets of experiments. By relating changes in the attenuation of green (central wavelength λ(c) = 568 nm) and infrared (λ(c) = 798 nm) light, the ratio of mean pathlengths travelled by photons in the skin blood plexus was obtained. The pathlength for infrared light is found to be 3.85 times larger than for green. Combining signals of two wavelengths and accounting for pathlength difference, we quantitatively characterize the CBC as a cumulative optical thickness of red blood cells in the skin plexus. The dielectric spectra of skin in the MHz range were fitted with the Cole-Cole model and the changes of parameters were quantitatively related to the optically derived changes in CBC using a linear regression analysis. The positive correlation with CBC is obtained for the dispersion exponent (R(2) = 0.68), and the negative-for the dispersion time (R(2) = 0.40). Thus dielectric dispersion of the skin gets broader and shifts towards lower frequencies with an increase of CBC.

Ion Channel Activity of Brain Abundant Protein BASP1 in Planar Lipid Bilayers

The FEBS Journal. Feb, 2011  |  Pubmed ID: 21156029

BASP1 (also known as CAP-23 and NAP-22) is a brain abundant myristoylated protein localized at the inner surface of the presynaptic plasma membrane. Emerging evidence suggests that BASP1 is critically involved in various cellular processes, in particular, in the accumulation of phosphatidylinositol-4,5-diphosphate (PIP(2)) in lipid raft microdomains. We have recently shown that BASP1 forms heterogeneously-sized oligomers and higher aggregates with an outward similarity to oligomers and protofibrils of amyloid proteins. However, BASP1 is not known to be related to any amyloid disease. In the present study, we show that BASP1 induces single channel currents across negatively-charged planar lipid bilayers (containing phosphatidylserine or PIP(2)) bathed in 0.1-0.2 M KCl (pH 7.5). By their characteristics, BASP1 channels are similar to amyloid protein channels. BASP1 channels exhibit multiple conductance levels, in the range 10-3000 pS, with the most frequently observed conductance state of approximately 50 pS. The channels demonstrate a linear current-voltage relationship and voltage-independent kinetics of opening and closing. Their K(+) to Cl(-) permeability ratio is approximately 14, indicating that BASP1 channels are cation-selective. The ion channel activity of BASP1 is in accordance with the pore-like structure of BASP1 oligomers observed by electron microscopy on a lipid monolayer. Neuronal protein GAP-43, which is functionally related to BASP1 and also forms oligomers, elicited no ion channel currents under the conditions used in the present study. Elucidation of the physiological or pathological roles of ion channel activity of membrane-bound BASP1 oligomers will help to define the precise mechanism of amyloid protein toxicity.

Complete DNA Barcode Reference Library for a Country's Butterfly Fauna Reveals High Performance for Temperate Europe

Proceedings. Biological Sciences / The Royal Society. Feb, 2011  |  Pubmed ID: 20702462

DNA barcoding aims to accelerate species identification and discovery, but performance tests have shown marked differences in identification success. As a consequence, there remains a great need for comprehensive studies which objectively test the method in groups with a solid taxonomic framework. This study focuses on the 180 species of butterflies in Romania, accounting for about one third of the European butterfly fauna. This country includes five eco-regions, the highest of any in the European Union, and is a good representative for temperate areas. Morphology and DNA barcodes of more than 1300 specimens were carefully studied and compared. Our results indicate that 90 per cent of the species form barcode clusters allowing their reliable identification. The remaining cases involve nine closely related species pairs, some whose taxonomic status is controversial or that hybridize regularly. Interestingly, DNA barcoding was found to be the most effective identification tool, outperforming external morphology, and being slightly better than male genitalia. Romania is now the first country to have a comprehensive DNA barcode reference database for butterflies. Similar barcoding efforts based on comprehensive sampling of specific geographical regions can act as functional modules that will foster the early application of DNA barcoding while a global system is under development.

Pushing the Limits of Steric Demand Around a Biaryl Axis: Synthesis of Tetra-ortho-substituted Biaryl Naphthalenes

Chemical Communications (Cambridge, England). Jan, 2011  |  Pubmed ID: 20730229

The synthesis of tetra-ortho-substituted biaryl naphthalenes, including examples bearing multiple ortho-isopropyl groups, has been developed via a catalytic rearrangement process.

Oxygen-dependent Auto-oscillations of Water Luminescence Triggered by the 1264 Nm Radiation

The Journal of Physical Chemistry. B. Jun, 2011  |  Pubmed ID: 21595433

A 5-min exposure of air-saturated bidistilled water to low-intensity laser infrared radiation at the wavelength of the electronic transition of dissolved oxygen to the singlet state ((3)∑(g)(-)→ (1)Δ(g)) induces, after a long latent period, auto-oscillations of water luminescence in the blue-green region, which last many hours. Laser irradiation causes the accumulation of hydrogen peroxide, which depends on the concentration of dissolved oxygen. The auto-oscillations do not arise if water is irradiated beyond the oxygen absorption band and if the oxygen is removed from water. The wavelet transform analysis of luminescence records indicates that there are two characteristic periods of pulsations of about 300 and 1150 s. The results obtained suggest that auto-oscillations are triggered by photoinduced singlet oxygen (1)Δ(g), and this phenomenon is closely related to formation of hydrogen peroxide.

Dynamics of Coregulator-induced Conformational Perturbations in Androgen Receptor Ligand Binding Domain

Molecular and Cellular Endocrinology. Jul, 2011  |  Pubmed ID: 21605623

Androgen receptor (AR) coregulators modulate ligand-induced gene expression in a tissue specific manner. The molecular events that follow coactivator binding to AR and the mechanisms that govern the sequence-specific effects of AR coregulators are poorly understood. Using consensus coactivator sequence D11-FxxLF and biophysical techniques, we show that coactivator association is followed by conformational rearrangement in AR ligand binding domain (AR-LBD) that is enthalpically and entropically favorable with activation energy of 29.8±4.2 kJ/mol. Further characterization of ARA70 and SRC3-1 based consensus sequences reveal that each coactivator induces a distinct conformational state in the dihydrotestosterone:AR-LBD:coactivator complex. Complementary computational modeling revealed that coactivator induced specific alterations in the backbone flexibility of AR-LBD distant from the site of coactivator binding and that the intramolecular rearrangements in AR-LBD backbone induced by the two coactivator peptides were different. These data suggest that coactivators may impart specificity in the transcriptional machinery by changing the steady-state conformation of AR-LBD. These data provide direct evidence that even in the presence of same ligand, AR-LBD can occupy distinct conformational states depending on its interactions with specific coactivators in the tissues. We posit that this coactivator-specific conformational gating may then dictate subsequent binding partners and interaction/affinity for the DNA-response elements.

[Percutaneous Coronary Interventions in Patients with Acute Myocardial Infarction After Unsuccessful Thrombolysis]

Kardiologiia. 2011  |  Pubmed ID: 21626803

In 176 patients with acute myocardial infarction admitted to N.V. Sklifosofsky institute of urgent aid in 2003-20007 we compared efficacy of 3 strategies of treatment after unsuccessful thrombolytic therapy (TLT): percutaneous coronary intervention (PCI) during first 24 hours (n = 30), PCI on days 2 or 3 (n = 38); conservative treatment (n = 108). The data obtained show that it is expedient to consider absence of 50% reduction of STAsegment elevations in 90 min after start of TLT as indication to urgent late PCI when possibilities for immediate intervention after unsuccessful thrombolysis are lacking. Alternative reperfusion is the only type of effective treatment of patients with failed pharmacological reperfusion. Necessity to perform PCI during first 12 hours after unsuccessful TLT does not exclude possibility of its later fulfillment in acute period of myocardial infarction. Efficacy of the latter is comparable with success rate of rescue PCI. The use of both invasive strategies has allowed to lessen rate of complications and prevent lethal outcomes. Success of late urgent interventions in acute period of infarction after failed thrombolysis opens possibilities for their active use in patients transferred from other hospitals.

Lithium Cation Enhances Anion Binding in a Tripodal Phosphine Oxide-based Ditopic Receptor

Chemical Communications (Cambridge, England). Jul, 2011  |  Pubmed ID: 21655566

A tripodal ditopic receptor presents H-bond donors and a phosphine oxide to potential guests. In the idealized binding conformation, an endohedral P=O functionality provides enhanced halide binding in the presence of lithium with the greatest ΔΔG° observed for bromide, while minimal changes in K(a) are observed in the presence of sodium.

Ancient Links Between Siberians and Native Americans Revealed by Subtyping the Y Chromosome Haplogroup Q1a

Journal of Human Genetics. Aug, 2011  |  Pubmed ID: 21677663

To investigate the structure of Y chromosome haplogroups R-M207 and Q-M242 in human populations of North Asia, we have performed high-resolution genotyping using both single nucleotide polymorphisms and short tandem repeat (STR)-based approaches of 121 M207- and M242-derived samples from 885 males of 16 ethnic groups of Siberia and East Asia. As a result, the following Y chromosome haplogroups were revealed: R1b1b1-M73 (2.0%), R1b1b2-M269 (0.7%), R2-M124 (1.1%), Q1a*-MEH2 (0.5%), Q1a2-M25 (0.1%), Q1a3*-M346 (9.2%) and Q1a3a-M3 (0.2%). Despite the low coalescence age of haplogroup Q1a3*-M346, which is estimated in South Siberia as about 4.5±1.5 thousand years ago (Ka), divergence time between these Q1a3*-M346 haplotypes and Amerindian-specific haplogroup Q1a3a-M3 is equal to 13.8±3.9 Ka, pointing to a relatively recent entry date to America. In addition, unique cluster of haplotypes belonging to Q1a*-MEH2 was found in Koryaks inhabiting the Sea of Okhotsk coast (at a frequency of 10.3%). Although the level of STR diversity associated with Q1a*-MEH2 is very low, this lineage appears to be closest to the extinct Palaeo-Eskimo individuals belonging to the Saqqaq culture arisen in the New World Arctic about 5.5 Ka. This finding suggests that Q1a*-MEH2 likely traces a population migration originating in Northeast Siberia across the Bering Strait.

[Overcoming Resistance of Tuberculosis Infectious Agent by Isoniazid-silver Nanocomposite]

Eksperimental'naia I Klinicheskaia Farmakologiia. 2011  |  Pubmed ID: 21678655

The antituberculous activity of a nanocomposite based on nanoparticulate silver and isoniazid has been studied on the model of drug-resistant tuberculosis in a group of 65 white mice. The possibility of overcoming the resistance of the tuberculosis activator by the proposed nanocomposite of isoniazid and nanoparticulate silver is demonstrated in terms of the survival index, biometric data, bacteriological and pathomorphological parameters. Dose-dependent parameters of the presence of nanoparticulate silver in the composite structure are established. The results of preclinical research scientifically prove good prospects for using nanoparticulate silver in the treatment of drug-resistant tuberculosis.

Monitoring Selected Hydrogen Bonds in Crystal Hydrates of Amino Acid Salts: Combining Variable-temperature Single-crystal X-ray Diffraction and Polarized Raman Spectroscopy

Physical Chemistry Chemical Physics : PCCP. Jul, 2011  |  Pubmed ID: 21687865

Predicting behaviour of hydrogen bonds with varying temperature, in particular-correlating donor-acceptor distances in the O-H···O hydrogen bonds with the frequencies of O-H stretching vibrations is important for understanding dynamics of biomolecules and phase transitions in crystals. A commonly used correlation suggested earlier in the literature is based on statistical analysis of different compounds [A. Novak, Structure and Bonding, 1974, 18, 177; K. Nakamoto, M. Margoshes, R. E. Rundle, J. Am. Chem. Soc., 1955, 77, 6480]. The present study is a rare example when correlations between geometry and energy parameters have been found for selected individual hydrogen bonds in the same crystalline compound at multiple temperatures. The properties of several types of O-H···O hydrogen bonds in bis(DL-serinium) oxalate dihydrate and DL-alaninium semi-oxalate monohydrate have been studied by a combination of variable-temperature single-crystal X-ray diffraction and polarized Raman spectroscopy. The changes in the hydrogen bonds geometry could be compared with the changes of the corresponding spectral modes. The correlation suggested by Novak is roughly followed, better for medium and weak, than for short hydrogen bonds. Fine details of spectral changes differ for individual bonds. The way how H-bonds are affected by cooling depends on their environment in the crystal structure. Short O-H···O hydrogen bonds in bis(DL-serinium) oxalate dihydrate expand or remain almost unchanged on cooling, whereas in DL-alaninium semi-oxalate monohydrate all strong H-bonds are compressed under these conditions. The distortion of individual hydrogen bonds on temperature variations is correlated with the anisotropy of lattice strain.

Synthesis of 7,7'-dihydroxy-8,8'-biquinolyl (azaBINOL) Via Pd-catalyzed Directed Double C-H Functionalization of 8,8'-biquinolyl: Emergence of an Atropos from a Tropos State

Organic Letters. Aug, 2011  |  Pubmed ID: 21714530

7,7'-Dihydroxy-8,8'-biquinolyl (azaBINOL) was prepared from 2-chloroaniline in four steps: (1) the Skraup reaction, (2) Ni-catalyzed reductive coupling of 8-chloroquinoline, (3) Pd(II)-catalyzed double C-H functionalization of 8,8'-biquinolyl mediated by PhI(OAc)(2), and (4) saponification. During the third step, an axially chiral (atropos type) biaryl molecule was directly generated from an essentially achiral (tropos type) biaryl starting material.

Boron in Disguise: the Parent "fused" BN Indole

Journal of the American Chemical Society. Aug, 2011  |  Pubmed ID: 21751771

"Fused" BN indoles are an emerging class of boron-containing indole mimics, featuring geometric structure and electophilic aromatic substitution reactivity similar to those of indoles but exhibiting distinct electronic structure, leading to unique optoelectronic properties. Herein we report the synthesis of the parent N-H BN indole and provide a head-to-head comparison of the structural features, pK(a) values, and optoelectronic properties of this hybrid organic/inorganic indole with the classic natural indole.

1,2-BN Cyclohexane: Synthesis, Structure, Dynamics, and Reactivity

Journal of the American Chemical Society. Aug, 2011  |  Pubmed ID: 21786818

BN/CC isosterism has emerged as a viable strategy to increase the structural diversity of carbon-based compounds. We present the first synthesis and characterization of the parent 1,2-BN cyclohexane, the BN-isostere of cyclohexane. 1,2-BN cyclohexane is an air- and water-stable compound that cleanly forms a trimer with release of dihydrogen when thermally activated. We also demonstrate that 1,2-BN cyclohexane has a lower activation barrier for ring inversion than cyclohexane due to BN/CC isosterism.

Reactions of Coordinated Hydroxymethylphosphines with NH-functional Amines: the Phosphorus Lone Pair is Crucial for the Phosphorus Mannich Reaction

Dalton Transactions (Cambridge, England : 2003). Sep, 2011  |  Pubmed ID: 21789320

Non-coordinated hydroxymethylphosphines react readily with primary and secondary amines by the phosphorus Mannich reaction. To determine if this reactivity can be used to synthesize phosphine macrocycles, trans-Fe(DHMPE)(2)Cl(2) (DHMPE = 1,2-bis(dihydroxymethylphosphino)ethane) was prepared and reacted with various amines. However, no phosphorus Mannich reactivity was observed. In order to understand why no reactions occurred, the Mannich reactivity of the borane-coordinated hydroxymethylphosphines DHMPE·2BH(3) and Ph(2)PCH(2)OH·BH(3) was investigated. These borane-coordinated phosphines also did not undergo the phosphorus Mannich reaction. These results suggest that the lone pair of electrons on the phosphorus atom is essential for the phosphorus Mannich reaction to occur, and therefore it is not possible to use this reaction in a templated synthesis of phosphine macrocycles. It is speculated that the mechanism of the phosphorus Mannich reaction may involve a methylenephosphonium intermediate, analogous to an iminium in the standard Mannich reaction. X-ray crystal structures of trans-Fe(DHMPE)(2)Cl(2) and DHMPE·2BH(3) are also presented. Both crystal structures display an extended hydrogen-bonding network in the solid state.

Design, Synthesis and Characterization of Self-assembled As2L3 and Sb2L3 Cryptands

Dalton Transactions (Cambridge, England : 2003). Dec, 2011  |  Pubmed ID: 21799975

The syntheses and X-ray crystal structures of six new self-assembled supramolecular As and Sb-containing cryptands are described. Analysis in the context of previously reported As(2)L(3) and Sb(2)L(3) cryptands reveals that small differences in ligand geometries result in significant differences in the helicity of the complexes and the stereochemistry of the metal coordination within the assembled complexes. Additionally, a new synthetic route is described which involves exposure of reactants to vacuum to help facilitate self-assembly.

Synthesis, Antifungal Activity and QSAR Study of 2-arylhydroxynitroindoles

European Journal of Medicinal Chemistry. Sep, 2011  |  Pubmed ID: 21802177

A series of 2-arylhydroxynitroindoles were prepared and tested for antifungal activity in vitro. The preliminary bioassays indicated that some compounds are comparable to the commercial fungicide (triadimefon). To further explore the structure-activity relationships, the data set of the seventeen structures and their quantitative values of antifungal activities were used for QSAR modeling. Based on the obtained QSAR models four new chemical compounds were designed, synthesized and tested in fungicidal assays. Reasonable correspondence between the experimental and predicted values of antifungal activity was observed.

Glycinium Semi-malonate and a Glutaric Acid-glycine Cocrystal: New Structures with Short O-H...O Hydrogen Bonds

Acta Crystallographica. Section C, Crystal Structure Communications. Aug, 2011  |  Pubmed ID: 21817796

Glycinium semi-malonate, C(2)H(6)NO(2)(+)·C(3)H(3)O(4)(-), (I), and glutaric acid-glycine (1/1), C(2)H(5)NO(2)·C(5)H(8)O(4), (II), are new examples of two-component crystal structures containing glycine and carboxylic acids. (II) is the first example of a glycine cocrystal which cannot be classified as a salt, as glutaric acid remains completely protonated. In the structure of (I), there are chains formed exclusively by glycinium cations, or exclusively by malonate anions, and these chains are linked with each other. Two types of very short O-H...O hydrogen bonds are present in the structure of (I), one linking glycinium cations with malonate anions, and the other linking malonate anions with each other. In contrast to (I), no direct linkages between molecules of the same type can be found in (II); all the hydrogen-bonded chains are heteromolecular, with molecules of neutral glutaric acid alternating with glycine zwitterions, linked by two types of short O-H...O hydrogen bonds.

Stacking Interaction and Its Role in Kynurenic Acid Binding to Glutamate Ionotropic Receptors

Journal of Molecular Modeling. Aug, 2011  |  Pubmed ID: 21833825

Stacking interaction is known to play an important role in protein folding, enzyme-substrate and ligand-receptor complex formation. It has been shown to make a contribution into the aromatic antagonists binding with glutamate ionotropic receptors (iGluRs), in particular, the complex of NMDA receptor NR1 subunit with the kynurenic acid (KYNA) derivatives. The specificity of KYNA binding to the glutamate receptors subtypes might partially result from the differences in stacking interaction. We have calculated the optimal geometry and binding energy of KYNA dimers with the four types of aromatic amino acid residues in Rattus and Drosophila ionotropic iGluR subunits. All ab initio quantum chemical calculations were performed taking into account electron correlations at MP2 and MP4 perturbation theory levels. We have also investigated the potential energy surfaces (PES) of stacking and hydrogen bonds (HBs) within the receptor binding site and calculated the free energy of the ligand-receptor complex formation. The energy of stacking interaction depends both on the size of aromatic moieties and the electrostatic effects. The distribution of charges was shown to determine the geometry of polar aromatic ring dimers. Presumably, stacking interaction is important at the first stage of ligand binding when HBs are weak. The freedom of ligand movements and rotation within receptor site provides the precise tuning of the HBs pattern, while the incorrect stacking binding prohibits the ligand-receptor complex formation.

Numerical and Asymptotic Approach for Evaluating Complex Wavenumbers of Guided Modes in Viscoelastic Plates

The Journal of the Acoustical Society of America. Aug, 2011  |  Pubmed ID: 21877792

The approximate description of the dispersion curves is obtained using asymptotics of complex wavenumbers for different boundary conditions on the plate surfaces. Their comparison with the exact results shows satisfactory agreement. This approach provides an algorithm to evaluate the infinite spectrum of non-propagating modes more easily and numerically stable even for wavenumbers of big values. Results are verified by the alternative semianalytical finite element method, which also supplies the mode shapes for better identification and classification.

Field-induced Periodic Distortions in a Nematic Liquid Crystal: Deuterium NMR Study and Theoretical Analysis

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics. Aug, 2011  |  Pubmed ID: 21929001

The peculiarities in the dynamic of the director reorientation in a liquid crystal (LC) film under the influence of the electric E field directed at an angle α to the magnetic B field have been investigated both experimentally and theoretically. Time-resolved deuterium NMR spectroscopy is employed to investigate the field-induced director dynamics. Analysis of the experimental results, based on the predictions of hydrodynamic theory including both the director motion and fluid flow, provides an evidence for the appearance of the spatially periodic patterns in 4-n-pentyl-4'-cyanobiphenyl LC film, at the angles α>60∘, in response to the suddenly applied E. These periodic distortions produce a lower effective rotational viscosity. This gives a faster response of the director rotation than for a uniform mode, as observed in our NMR experiment.

Dielectric and Piezoelectric Properties of PbFe1/2Nb1/2O3-PbTiO3 Ceramics from the Morphotropic Phase Boundary Compositional Range

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. Sep, 2011  |  Pubmed ID: 21937325

Dielectric, X-ray, and piezoelectric studies of highly-resistive Li-doped (1-x)PbFe(1/2)Nb(1/2)O(3)-(x)PbTiO(3) (PFN-xPT) ceramics from the 0 ≤ x ≤ 0.2 range fabricated by solid-state synthesis and usual sintering have been carried out. Distinct anomalies of dielectric and piezoelectric parameters, corresponding to the transition between rhombohedral (monoclinic) and tetragonal ferroelectric phases, have been observed in pure PFN and PFN-xPT compositions with PbTiO(3) content up to 8 mol.%. The x,T-phase diagram of the PFN-xPT solid solution system has been constructed using these data.

[Information Technology in the Management of Medical Support NATO's Force]

Voenno-medit͡sinskiĭ Zhurnal. Jul, 2011  |  Pubmed ID: 21938896

The analysis of various control systems of troops (forces) of NATO's force is performed. It is shown that much experience in building automated control systems for operational and strategic level as the rear, and medical services. However, the experience of wars and military conflicts of the last decade has shown convincingly that solutions to complex issues of command and control units, as well as their interaction is possible only through an integrated approach--automation, not only those who first come into the fight, but the forces and means, involved in their welfare. Given direction is implemented in the U.S. Army's development of automation, in particular, telemedicine.

[Effectiveness of Early Invasive Strategy of Treatment of Angina of New Onset]

Kardiologiia. 2011  |  Pubmed ID: 21943004

Aim of the study was to assess effectiveness of early invasive strategy of treatment of angina of new onset (ANO). We conducted comparative assessment on invasive and noninvasive risk estimation in 106 patients admitted to N.V.Sklifosofsky Institute of Urgent Aid in 2003-2007. Percutaneous coronary interventions (PCI) on symptom related artery (SRA) within single procedure were carried out in 74 cases (70%), indications to coronary artery bypass surgery were detected in 16 cases (15%), in 16 more cases conservative treatment was used. The data obtained showed that it is rational to consider ANO as unstable angina in all cases including those without progression. Visualization of coronary arteries gives possibility to define significance of SRA and zone at risk of injury, determine indications to myocardial revascularization, and avoid inadequacy of noninvasive assessment of risk and choice of treatment tactics. The method of choice in the treatment of patients with ANO is PCI performed during single procedure. Detection of indications to coronary artery bypass surgery in low risk patients and in absence of progression confirm necessity of routine use of invasive strategy which provides timely pathogenetic treatment. Absence of indications to myocardial revascularization detected in sporadic cases provides possibility to avoid groundless hospitalizations.

Follow-up of Cortical Activity and Structure After Lesion with Laser Speckle Imaging and Magnetic Resonance Imaging in Nonhuman Primates

Journal of Biomedical Optics. Sep, 2011  |  Pubmed ID: 21950925

The nonhuman primate model is suitable to study mechanisms of functional recovery following lesion of the cerebral cortex (motor cortex), on which therapeutic strategies can be tested. To interpret behavioral data (time course and extent of functional recovery), it is crucial to monitor the properties of the experimental cortical lesion, induced by infusion of the excitotoxin ibotenic acid. In two adult macaque monkeys, ibotenic acid infusions produced a restricted, permanent lesion of the motor cortex. In one monkey, the lesion was monitored over 3.5 weeks, combining laser speckle imaging (LSI) as metabolic readout (cerebral blood flow) and anatomical assessment with magnetic resonance imaging (T2-weighted MRI). The cerebral blood flow, measured online during subsequent injections of the ibotenic acid in the motor cortex, exhibited a dramatic increase, still present after one week, in parallel to a MRI hypersignal. After 3.5 weeks, the cerebral blood flow was strongly reduced (below reference level) and the hypersignal disappeared from the MRI scan, although the lesion was permanent as histologically assessed post-mortem. The MRI data were similar in the second monkey. Our experiments suggest that LSI and MRI, although they reflect different features, vary in parallel during a few weeks following an excitotoxic cortical lesion.

Electron-accepting 6,12-diethynylindeno[1,2-b]fluorenes: Synthesis, Crystal Structures, and Photophysical Properties

Angewandte Chemie (International Ed. in English). Nov, 2011  |  Pubmed ID: 21953794

[The Ants: a Strategy of Population Concentration]

Zhurnal Obshcheĭ Biologii. Jul-Aug, 2011  |  Pubmed ID: 21954628

Ants are provided with a balanced system of reactions either to the original paucity of socia or to their secondary depopulation. This system can be defined as a strategy of population concentration. Both a successful reproduction of workers and queen fertilization are necessary conditions for ant communities' survival and development. Thus, the anthills must be large enough to ensure optimal conditions for reproduction. It is the strategy of population concentration that is directed to an accelerated attainment (or rehabilitation) by a socium of a state of stable development by way of concentrating the existent ant staff in an accessible number of viable nests. This strategy is realized throughout the life of ant communities by way of (a) fusing the starting family cells left by founder females, (b) fusing small anthills during artificial ant migrations, (c) uniting smaller socia or their joining other anthills, (d) reintegrating the secondary anthills (fragmentants) after an exogenous fragmentation of formicaries. Pooling and the attraction of deficient demographic resources from outside form the most efficient and quickest ways of reaching or restoring the threshold density levels. By realizing this strategy, the ants solve their paramount problems of anthill or settlement conservation at any particular time, as well as of providing some prospects for ant existence in the future. These problems are so vital for ant socia that they appear to hold priority over such other characteristics of utmost importance as genetic kinship or even species identity. The priority of social basics over genetic ones is unequivocally supported through mixed formicaries. A necessary condition for the realization of the strategy of population concentration is tolerance of highly developed social systems to the diversity of forms and to deviations from the norm. The use of one and the same mechanism at all stages of the life both of an individual socium and large ant settlements is evidence of the universality of this strategy, as well as of its unconditioned importance to the life of ant communities.

[Correlation of Structurally-functional Cardiac Condition and Levels of Erythropoietin, Tumour Necrosis Factor-alpha in Blood in Heart Failure]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Aug, 2011  |  Pubmed ID: 21961313

Structurally-functional myocardium parameters and their interconnection with erythropoietin and tumour necrosis factor-alpha levels in blood plasma of patients with heart failure were analysed. Prevalence of erythropoietin over tumour necrosis factor-alpha in blood had positive effect on myocardium-contraction ability under acute heart failure. Improvement of pumped cardiac function was not registered under prevalence of erythropoietin over tumour necrosis faetor-a in blood of patients with chronic heart failure.

Inferring the Origin of Populations Introduced from a Genetically Structured Native Range by Approximate Bayesian Computation: Case Study of the Invasive Ladybird Harmonia Axyridis

Molecular Ecology. Nov, 2011  |  Pubmed ID: 22004292

Correct identification of the source population of an invasive species is a prerequisite for testing hypotheses concerning the factors responsible for biological invasions. The native area of invasive species may be large, poorly known and/or genetically structured. Because the actual source population may not have been sampled, studies based on molecular markers may generate incorrect conclusions about the origin of introduced populations. In this study, we characterized the genetic structure of the invasive ladybird Harmonia axyridis in its native area using various population genetic statistics and methods. We found that native area of H. axyridis most probably consisted of two geographically distinct genetic clusters located in eastern and western Asia. We then performed approximate Bayesian computation (ABC) analyses on controlled simulated microsatellite data sets to evaluate (i) the risk of selecting incorrect introduction scenarios, including admixture between sources, when the populations of the native area are genetically structured and sampling is incomplete and (ii) the ability of ABC analysis to minimize such risks by explicitly including unsampled populations in the scenarios compared. Finally, we performed additional ABC analyses on real microsatellite data sets to retrace the origin of biocontrol and invasive populations of H. axyridis, taking into account the possibility that the structured native area may have been incompletely sampled. We found that the invasive population in eastern North America, which has served as the bridgehead for worldwide invasion by H. axyridis, was probably formed by an admixture between the eastern and western native clusters. This admixture may have facilitated adaptation of the bridgehead population.

A Single-component Liquid-phase Hydrogen Storage Material

Journal of the American Chemical Society. Dec, 2011  |  Pubmed ID: 22070729

The current state-of-the-art for hydrogen storage is compressed H(2) at 700 bar. The development of a liquid-phase hydrogen storage material has the potential to take advantage of the existing liquid-based distribution infrastructure. We describe a liquid-phase hydrogen storage material that is a liquid under ambient conditions (i.e., at 20 °C and 1 atm pressure), air- and moisture-stable, and recyclable; releases H(2) controllably and cleanly at temperatures below or at the proton exchange membrane fuel cell waste-heat temperature of 80 °C; utilizes catalysts that are cheap and abundant for H(2) desorption; features reasonable gravimetric and volumetric storage capacity; and does not undergo a phase change upon H(2) desorption.

Analysis of Medication Errors of Health Care Providers on the Basis of Data from the Czech Toxicological Information Centre over an 11-Year Period (2000-2010)

Basic & Clinical Pharmacology & Toxicology. Nov, 2011  |  Pubmed ID: 22077968

  This study aimed to analyse medication errors committed by health care professionals leading to toxicological consultations at the Czech Toxicological Information Centre and to identify the categories of special concern for further interventions of health care quality experts.

Membrane Proteins in Four Acts: Function Precedes Structure Determination

Methods (San Diego, Calif.). Dec, 2011  |  Pubmed ID: 22079407

Studies on four membrane protein systems, which combine information derived from crystal structures and biophysical studies have emphasized, as a precursor to crystallization, demonstration of functional activity. These assays have relied on sensitive spectrophotometric, electrophysiological, and microbiological assays of activity to select purification procedures that lead to functional complexes and with greater likelihood to successful crystallization: (I), Hetero-oligomeric proteins involved in electron transport/proton translocation. (1) Crystal structures of the eight subunit hetero-oligomeric trans-membrane dimeric cytochrome b(6)f complex were obtained from cyanobacteria using a protocol that allowed an analysis of the structure and function of internal lipids at specific intra-membrane, intra-protein sites. Proteolysis and monomerization that inactivated the complex and prevented crystallization was minimized through the use of filamentous cyanobacterial strains that seem to have a different set of membrane-active proteases. (2) An NADPH-quinone oxido-reductase isolated from cyanobacteria contains an expanded set of 17 monotopic and polytopic hetero-subunits. (II) β-Barrel outer membrane proteins (OMPs). High resolution structures of the vitamin B(12) binding protein, BtuB, solved in meso and in surfo, provide the best example of the differences in such structures that were anticipated in the first application of the lipid cubic phase to membrane proteins [1]. A structure of the complex of BtuB with the colicin E3 and E2 receptor binding domain established a "fishing pole" model for outer membrane receptor function in cellular import of nuclease colicins. (III) A modified faster purification procedure contributed to significantly improved resolution (1.83Å) of the universal porin, OmpF, the first membrane protein for which meaningful 3D crystals have been obtained [2]. A crystal structure of the N-terminal translocation domain of colicin E3 complexed to OmpF established the role of OmpF as an import channel for colicin nuclease cytotoxins. (IV) α-Synuclein, associated with the etiology of Parkinson's Disease, is an example of a protein, which is soluble and disordered in solution, but which can assume an ordered predominantly α-helical conformation upon binding to membranes. When subjected in its membrane-bound form to a trans-membrane electrical potential, α-synuclein can form voltage-gated ion channels. Summary of methods to assay functions/activities: (i) sensitive spectrophotometric assay to measure electron transfer activities; (ii) hydrophobic chromatography to deplete lipids, allowing reconstitution with specific lipids for studies on lipid-protein interactions; (iii) microbiological screen to assay high affinity binding of colicin receptor domains to Escherichia coli outer membrane receptors; (iv) electrophysiology/channel analysis (a) to select channel-occluding ligands for co-crystallization with ion channels of OmpF, and (b) to provide a unique description of voltage-gated ion channels of α-synuclein.

A 1,3-dihydro-1,3-azaborine Debuts

Journal of the American Chemical Society. Dec, 2011  |  Pubmed ID: 22091703

We present the first synthesis and characterization of a 1,3-dihydro-1,3-azaborine, a long-sought BN isostere of benzene. 1,3-Dihydro-1,3-azaborine is a stable structural motif with considerable aromatic character as evidenced by structural analysis and its reaction chemistry. Single crystal X-ray analysis indicates bonding consistent with significant electron delocalization. 1,3-Dihydro-1,3-azaborines also undergo nucleophilic substitutions at boron and electrophilic aromatic substitution reactions. In view of the versatility and impact of aromatic compounds in the biomedical field and in materials science, the present study further expands the available chemical space of arenes via BN/CC isosterism.

Molecular Self Assembly: Solvent Guests Tune the Conformation of a Series of 2,6-Bis(2-anilinoethynyl)pyridine-Based Ureas

Crystal Growth & Design. Nov, 2011  |  Pubmed ID: 22102795

The conformations of 2,6-bis(2-anilinoethynyl)pyridine-based urea receptors were studied by single crystal X-ray diffraction methods and revealed a rich conformational flexibility influenced by solvents. Whereas receptor L(1) in DMSO prefers an "S" conformation, receptor L(1) crystallizes in an "O" conformation from DMSO/CH(3)OH binary solvent system, and a "W" conformation in the ternary solvent mixture DMSO/toluene/1,4-dioxane. In the case of L(2), the molecule adopts an "S" conformation where water molecules are sandwiched between two molecules of L(2) to form a dimer. Similar to L(2), L(3) also forms a dimer where water molecules are sandwiched between L(3) molecules, which are capped with two molecules of DMSO. Such a capping DMSO solvate is lacking in the case of L(2). Taken together, these results demonstrate that the conformation of 2,6-bis(2-anilinoethynyl) pyridine-based urea receptors can be dramatically manipulated and tuned by the choice of crystallization solvents.

[Early and Postponed Percutaneous Coronary Interventions in Acute Period of Myocardial Infarction]

Kardiologiia. 2011  |  Pubmed ID: 22117765

Aim of the study was elaboration of indications to the application of postponed percutaneous coronary interventions (PCI) in acute period of myocardial Infarction (Ml) in patients without prior thrombolytic therapy. We fulfilled comparative assessment of efficacy of 3 strategies of treatment of 810 patients admitted to the N.V. Sklifosovsky Institute of Urgent Aid from 2003 to 2007: primary PCI carried out within first 12 hours (n=32), postponed PCI in acute period because of initially elevated risk (n=90), conservative treatment without reperfusion therapy (n=688). Elevated risk of death according to TIMI score was used as the basis for establishment of indications for postponed interventions. Right ventricular involvement and repeat MI were considered as additional predictors. The data obtained indicate that elevated risk of death allows to detect patients with high rate of persisting occlusions and subtotal stenoses in infarct related artery. Reperfusion therapy appears to be the main component of treatment of such patients. Necessity to perform primary PCI within first 12 hours does not exclude possibility of its later use in acute period of MI. Both strategies allow to substantially lower rates of complications and lethal outcomes. Shortening of terms of application of reperfusion therapy gives an opportunity to prevent most of unfavorable outcomes. Success of postponed interventions in acute period of MI opens opportunities of their active use in patients from other hospitals.

Synthesis, Crystal Structures, and Photophysical Properties of Electron-accepting Diethynylindenofluorenediones

Organic Letters. Apr, 2011  |  Pubmed ID: 21428314

A series of 6,12-bis[(trialkylsilyl)ethynyl]indeno[1,2-b]fluorene-5,11-diones has been synthesized. X-ray crystallographic analysis of these compounds reveals that triisopropylsilyl (TIPS) substitution on the alkyne terminus affords the largest number of intermolecular π-π interactions in the solid state. Conversely, use of trialkylsilyl groups smaller or larger than TIPS furnishes a variety of crystal-packing motifs that contain fewer π-π interactions. Electrochemical and photophysical data suggest that these molecules are excellent electron-accepting materials.

Pressure Perturbation Calorimetry of Lipoproteins Reveals an Endothermic Transition Without Detectable Volume Changes. Implications for Adsorption of Apolipoprotein to a Phospholipid Surface

Biochemistry. May, 2011  |  Pubmed ID: 21452855

Plasma lipoproteins are assemblies of lipids and apolipoproteins that mediate lipid transport and metabolism. High-density lipoproteins (HDL) remove excess cell cholesterol and provide protection against atherosclerosis. Important aspects of metabolic HDL remodeling, including apolipoprotein dissociation and lipoprotein fusion, are mimicked in thermal denaturation. We report the first study of the protein-lipid complexes by pressure perturbation calorimetry (PPC) beyond 100 °C. In PPC, volume expansion coefficient α(v)(T) is measured during heating; in proteins, α(v)(T) is dominated by hydration. Calorimetric studies of reconstituted HDL and of human high-density, low-density, and very low-density lipoproteins reveal that apolipoprotein unfolding, dissociation, and lipoprotein fusion are endothermic transitions without detectable volume changes. This may result from the limited applicability of PPC to slow kinetically controlled transitions such as thermal remodeling of lipoproteins and/or from the possibility that this remodeling causes no significant changes in the solvent structure and, hence, may not involve large transient solvent exposure of apolar moieties. Another conclusion is that apolipoprotein A-I in solution adsorbs to the phospholipid surface; protein hydration is preserved upon such adsorption. We posit that adsorption to a phospholipid surface helps recruit free apolipoprotein to the plasma membrane and facilitate HDL biogenesis.

Intermediate and Bragg Acousto-optic Interaction in Elastically Anisotropic Medium

Ultrasonics. Aug, 2011  |  Pubmed ID: 21458017

The Raman-Nath, intermediate and Bragg regimes of acousto-optic interaction in an acoustically anisotropic medium are theoretically examined in the paper. The general model of the interaction is extended over the case of an elastically anisotropic medium. Basic results of computer modeling of diffraction processes taking place in crystals are presented in the paper. The interaction of light and ultrasound is investigated in media with arbitrary elastic anisotropy in a wide range of the Klein-Cook and Raman-Nath parameters. The influence of the acoustic anisotropy on the process of light diffraction, especially on the light intensity in diffraction maxima, is also discussed.

Functional Changes in the Snail Statocyst System Elicited by Microgravity

PloS One. 2011  |  Pubmed ID: 21479267

The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations.

[Expression of the Catalytic Antibodies in Eukaryotic Systems]

Molekuliarnaia Biologiia. Jan-Feb, 2011  |  Pubmed ID: 21485500

Expression of recombinant antibodies in mammalian cells is one of key problems in immunobiotechnology. Alternatively, expression of a broad panel of antibodies and of their fragments may be effectively done in yeast cells. We obtained expression strains of the methylotrophic beast Pichia pastoris producing single chain human catalytic antibody A17 (A.17scFv), Fab-fragment (A.17Fab) and full-size light chain (A.17Lch). These antibodies were characterized in terms of functional activity. The capacity to specifically bind and transform organophosphorus compounds has been demonstrated for A.17scFv and A.17Fab. The loss of activity of the antibody light chain when expressed alone indicates that the active site is formed by both heavy and light chains of the antibody. We determined the reversible constant Kd and the first order constant (k2) of the reaction of the covalent modification of A.17scFv and A.17Fab by irreversible inhibitor of the serine proteases p-nitrophenyl 8-methyl-8-azobicyclo[3.2.1]phosphonate (Phosphonate X). Calculated values indicate that activity of the antibodies expressed in yeast is similar to the full-size antibody A17 and single chain antibody A.17 expressed in CHO and E. coli cells respectively.

Characteristics of a Multisensor System for Non Invasive Glucose Monitoring with External Validation and Prospective Evaluation

Biosensors & Bioelectronics. Apr, 2011  |  Pubmed ID: 21493056

The Multisensor Glucose Monitoring System (MGMS) features non invasive sensors for dielectric characterisation of the skin and underlying tissue in a wide frequency range (1kHz-100MHz, 1 and 2GHz) as well as optical characterisation. In this paper we describe the results of using an MGMS in a miniaturised housing with fully integrated sensors and battery. Six patients with Type I Diabetes Mellitus (age 44±16y; BMI 24.1±1.3kg/m(2), duration of diabetes 27±12y; HbA1c 7.3±1.0%) wore a single Multisensor at the upper arm position and performed a total of 45 in-clinic study days with 7 study days per patient on average (min. 5 and max. 10). Glucose changes were induced either orally or by i.v. glucose administration and the blood glucose was measured routinely. Several prospective data evaluation routines were applied to evaluate the data. The results are shown using one of the restrictive data evaluation routines, where measurements from the first 22 study days were used to train a linear regression model. The global model was then prospectively applied to the data of the remaining 23 study days to allow for an external validation of glucose prediction. The model application yielded a Mean Absolute Relative Difference of 40.8%, a Mean Absolute Difference of 51.9mgdL(-1), and a correlation of 0.84 on average per study day. The Clarke error grid analyses showed 89.0% in A+B, 4.5% in C, 4.6% in D and 1.9% in the E region. Prospective application of a global, purely statistical model, demonstrates that glucose variations can be tracked non invasively by the MGMS in most cases under these conditions.

The Assessment of Expert Testimony Relevance and Admissibility in Medical Malpractice Cases in the Czech Republic. Can American Judicial Practice Help Us?

Medicine and Law. Mar, 2011  |  Pubmed ID: 21528803

The relevance and admissibility of expert medical testimony in relation to medical malpractice suits requires a more successful development of formal criteria and a more intentional compliance with efficient judicial procedures. The American judicial system provides an excellent model for implementation of a critical approach to knowledge collection, the evaluation of the validity of scientifically sound information, and the examination of expert's testimony on the basis of a sound methodology. An analysis of the assessment and application of reliability yields evidence that assuring standards to improve the quality of expert medical testimony will increase the overall probability of a fair outcome during the judicial process. Applying these beneficial strategies in medical malpractice cases will continue to support further considerations of promoting justice and solving problems through sufficient scientific means.

Coarctate Versus Pericyclic Reactivity in Naphthalene-fused Azo-ene-ynes: Synthesis of Benzocinnolines and Benzoisoindazoles

Chemistry (Weinheim an Der Bergstrasse, Germany). Jun, 2011  |  Pubmed ID: 21542030

The cyclization reactions of naphthalene-fused azo-ene-yne compounds are explored both computationally and experimentally. Calculations reveal that naphtho-fusion to an azo-ene-yne scaffold does not significantly alter the transition state energies compared to the benzene-based systems; however, fusing the naphthalene in an angular fashion leads to lower energy intermediates due to the creation of arenes possessing greater aromaticity. Experimentally, the cyclization of the angular systems yields not only the expected monomeric benzocinnolines and benzoisoindazoles, but also several dimeric structures, including one that readily isomerizes in the presence of light and/or trace acid.

Indeno[1,2-b]fluorenes: Fully Conjugated Antiaromatic Analogues of Acenes

Angewandte Chemie (International Ed. in English). Feb, 2011  |  Pubmed ID: 21268210

Cationic 1,2-Azaborine Adducts of Trimethylphosphine, Triphenylphosphine Oxide, and Pyridine-N-oxide

Organometallics. Jan, 2011  |  Pubmed ID: 21278846

The first cationic 1,2-azaborine adducts of neutral phosphorous- and oxygen-based nucleophiles have been synthesized and characterized via spectroscopic and single crystal X-ray diffraction analysis.

Role of the Androgen Receptor CAG Repeat Polymorphism in Prostate Cancer, and Spinal and Bulbar Muscular Atrophy

Life Sciences. Mar, 2011  |  Pubmed ID: 21284948

Androgens are involved in the development of several tissues, including prostate, skeletal muscle, bone marrow, hair follicles, and brain. Most of the biological effects of the androgens are mediated through an intracellular transcription factor, the androgen receptor (AR) at the level of gene regulation. Several types of mutations in the AR gene have been linked to endocrine dysfunctions. The expansion of CAG codon repeat, coding for a polyglutamine (PolyQ) tract in the N-terminal domain is one such mutation. The polyQ chain length impacts AR's ability to interact with critical coregulators, which in turn modulates its transcriptional efficacy. Pathologic manifestations of variations in polyQ chain length have been associated with prostate cancer susceptibility, and the Spinal and Bulbar Muscular Atrophy (SBMA), a neurodegenerative disease. In this review article, we discuss multiple aspects of the role of polyQ chain length in the actions of the AR, their importance in prostate cancer development and progression, and SBMA with an aim to understand the underlying mechanisms involved in these diseases, which can be targeted for future therapeutic approaches.

DL-alaninium Semi-oxalate Monohydrate

Acta Crystallographica. Section C, Crystal Structure Communications. Feb, 2011  |  Pubmed ID: 21285500

The structure of the title compound, C(3)H(8)NO(2)(+)·C(2)HO(4)(-)·H(2)O, is formed by two chiral counterparts (L- and D-alaninium cations), semi-oxalate anions and water molecules, with a 1:1:1 cation-anion-water ratio. The structure is compared with that of the previously known anhydrous DL-alaninium semi-oxalate [Subha Nandhini, Krishnakumar & Natarajan (2001). Acta Cryst. E57, o666-o668] in order to investigate the role of water molecules in the crystal packing. The structure of the hydrate resembles that of anhydrous alaninium semi-oxalate, with the water molecule incorporated into the general three-dimensional network of hydrogen bonds where it forms four hydrogen bonds with neighbours disposed tetrahedrally about it. Although the main structural motifs in the hydrate and in the anhydrous form are topologically similar, the incorporation of water molecules in the network results in significant geometric distortion. There are several types of hydrogen bond in the crystal structure of the hydrate, two of which (O-H···O bonds between the semi-oxalate anions and O-H···O hydrogen bonds between water and alaninium cations) are very short. Such hydrogen bonds between semi-oxalate anions are also present in the anhydrous form of this compound. Short distances between semi-oxalate anions in neighbouring chains in the hydrate alternate with longer ones, whereas in the anhydrous structure they are equidistant. Despite the similarity of these compounds, dehydration of the hydrate on storage is not of a single-crystal to single-crystal type, but gives a polycrystalline pseudomorph, preserving the crystal habit. This transformation proceeds through the formation of an intermediate compound, presumably a hemihydrate.

Complexation Equilibria Involving Salts in Non-Aqueous Solvents: Ion Pairing and Activity Considerations

Chemistry (Weinheim an Der Bergstrasse, Germany). Feb, 2011  |  Pubmed ID: 21308807

Complexation of anions, cations and even ion pairs is now an active area of investigation in supramolecular chemistry; unfortunately it is an area fraught with complications when these processes are examined in low polarity organic media. Using a pseudorotaxane complex as an example, apparent K(a2) values (=[complex]/{[salt](o) -[complex]}{[host](o) -[complex]}) for pseudorotaxane formation from dibenzylammonium salts (2-X) and dibenzo-[24]crown-8 (1, DB24C8) in CDCl(3) /CD(3) CN 3:2 vary with concentration. This is attributable to the fact that the salt is ion paired, but the complex is not. We report an equilibrium model that explicitly includes ion pair dissociation and is based upon activities rather than molar concentrations for study of such processes in non-aqueous media. Proper analysis requires both a dissociation constant, K(ipd) , for the salt and a binding constant for interaction of the free cation 2(+) with the host, K(a5) ; K(a5) for pseudorotaxane complexation is independent of the counterion (500 M(-1) ), a result of the complex existing in solution as a free cation, but K(ipd) values for the salts vary by nearly two orders of magnitude from trifluoroacetate to tosylate to tetrafluoroborate to hexafluorophosphate anions. The activity coefficients depend on the nature of the predominant ions present, whether the pseudorotaxane or the ions from the salt, and also strongly on the molar concentrations; activity coefficients as low as 0.2 are observed, emphasizing the magnitude of their effect. Based on this type of analysis, a method for precise determination of relative binding constants, K(a5) , for multiple hosts with a given guest is described. However, while the incorporation of activity coefficients is clearly necessary, it removes the ability to predict from the equilibrium constants the effects of concentration on the extent of binding, which can only be determined experimentally. This has serious implications for study of all such complexation processes in low polarity media.

Iterative Stereospecific Reagent-controlled Homologation Using a Functionalized α-chloroalkyllithium: Synthesis of Cyclic Targets Related to Epibatidine

Organic Letters. Mar, 2011  |  Pubmed ID: 21338072

Enantioenriched 1-chloro-2-(1,3-dioxolan-2-yl)ethyllithium was generated by PhLi initiated sulfoxide-ligand exchange and deployed in situ for sequential double stereospecific reagent-controlled homologation (StReCH) of B-(2-chloro-pyrid-5-yl) pinacol boronate. This process afforded highly functionalized contiguous stereodiad motifs (typically, % ee ≥ 98%, dr ≥ 85:15) amenable to subsequent annulative transformations as demonstrated by the concise synthesis (5-7 steps) of cyclic adducts related to the analgesic alkaloid epibatidine.

Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas

Physical Review Letters. Feb, 2011  |  Pubmed ID: 21405577

Progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal plasmas is reported. The turbulence-driven intrinsic torque associated with nonlinear residual stress generation due to zonal flow shear induced asymmetry in the parallel wave number spectrum is shown to scale close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing experimental empirical scalings of intrinsic rotation. The origin of current scaling is found to be enhanced k(∥) symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The intrinsic torque is proportional to the pressure gradient because both turbulence intensity and zonal flow shear, which are two key ingredients for driving residual stress, increase with turbulence drive, which is R/L(T(e)) and R/L(n(e)) for the trapped electron mode.

Observation of Free Surface-induced Bending Upon Nanopatterning of Ultrathin Strained Silicon Layer

Nanotechnology. Jan, 2011  |  Pubmed ID: 21157010

We provide evidence of nanopatterning-induced bending of an ultrathin tensile strained silicon layer directly on oxide. This strained layer is achieved through the epitaxial growth of silicon on a Si(0.84)Ge(0.16) virtual substrate and subsequent transfer onto a SiO(2)-capped silicon substrate by combining hydrophilic wafer bonding and the ion-cut process. Using high resolution transmission electron microscopy, we found that the upper face of the strained silicon nanostructures fabricated from the obtained heterostructure using electron beam lithography and dry reactive ion etching displays a concave shape. This bending results from the free-surface-induced strain relaxation, which implies lattice out-of-plane expansion near the edges and concomitant contraction at the center. For a ∼ 110 nm × 400 nm × 20 nm nanostructure, the bending is associated with an angle of 1.5° between the [Formula: see text] vertical atomic planes at the edges of the ∼ 110 nm side. No bending is, however, observed at the strained Si/SiO(2) interface. This phenomenon cannot be explained by the classical Stoney's formula or related formulations developed for nanoscale thin films. Here we employed a continuum mechanical approach to describe these observations using three-dimensional numerical calculations of relaxation-induced lattice displacements.

Guanidinium Chloride-induced Spectral Perturbations of 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic Acid Confound Interpretation of Data on Molten Globule States

Analytical Biochemistry. Sep, 2011  |  Pubmed ID: 21569754

We describe limitations in the use of 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid (bis-ANS) to examine unfolding intermediates associated with guanidinium chloride (GuHCl)-induced protein denaturation. Several studies have used alterations in fluorescence emission of bis-ANS to quantify the population of "molten globule" states. Our findings indicate that the observed changes in bis-ANS spectroscopic properties could originate from the interactions of bis-ANS and GuHCl and the aggregation of the dye at higher GuHCl concentrations. We posit that in the absence of additional complementary structural or spectroscopic measurements, the use of bis-ANS emission alone to monitor protein conformations can be misleading.

Bis{1,2-bis-[bis-(3-meth-oxy-prop-yl)phosphan-yl]ethane-κP,P'}dichlorido-osmium(II)

Acta Crystallographica. Section E, Structure Reports Online. Dec, 2011  |  Pubmed ID: 22199590

In the centrosymmetric title compound, [OsCl(2)(C(18)H(40)O(4)P(2))(2)], the Os(II) atom adopts a trans-OsCl(2)P(4) geometry, arising from its coordination by two chelating diphosphane ligands and two chloride ions. One of the meth-oxy side chains of the ligand is disordered over two orientations in a 0.700 (6):0.300 (6) ratio.

On the Activation of Calcium-dependent Proteolysis in Brain Neurons of Spontaneously Hypertensive Rats (SHR Strain)

Bulletin of Experimental Biology and Medicine. Mar, 2011  |  Pubmed ID: 22235391

Females of spontaneously hypertensive (SHR strain) and normotensive rats (WKY strain and Wistar) received drinking water with normal (80 mg/liter) or reduced concentration of Ca(2+)(8 mg/liter). Activity of calcium-dependent calpain protease in neurons did not differ in 18-day-old rat pups born and suckled by these animals. Our results are consistent with published data on normal metabolism of SHR rats up to the age of 30 days.

The Dynamic Structure of the Estrogen Receptor

Journal of Amino Acids. 2011  |  Pubmed ID: 22312471

The estrogen receptor (ER) mediates most of the biological effects of estrogens at the level of gene regulation by interacting through its site-specific DNA and with other coregulatory proteins. In recent years, new information regarding the dynamic structural nature of ER has emerged. The physiological effects of estrogen are manifested through ER's two isoforms, ER(α) and ER(β). These two isoforms (ER(α) and ER(β)) display distinct regions of sequence homology. The three-dimensional structures of the DNA-binding domain (DBD) and ligand-binding domain (LBD) have been solved, whereas no three-dimensional natively folded structure for the ER N-terminal domain (NTD) is available to date. However, insights about the structural and functional correlations regarding the ER NTD have recently emerged. In this paper, we discuss the knowledge about the structural characteristics of the ER in general and how the structural features of the two isoforms differ, and its subsequent role in gene regulation.

[Regulation of Erythropoiesis in the Erythroblast Islands of the Bone Marrow]

Rossiĭskii Fiziologicheskiĭ Zhurnal Imeni I.M. Sechenova / Rossiĭskaia Akademiia Nauk. Sep, 2011  |  Pubmed ID: 22165209

The review describes the mechanisms of interactions between regulatory systems in regulation of erythropoiesis in the erythroblast islands of the bone marrow.

One-dimensional Corrugation of the H-BN Monolayer on Fe(110)

Langmuir : the ACS Journal of Surfaces and Colloids. Jan, 2012  |  Pubmed ID: 22185488

We report on a new nanopatterned structure represented by a single atomic layer of hexagonal boron nitride (h-BN) forming long periodic waves on the Fe(110) surface. The growth process and the structure of this system are characterized by X-ray absorption (XAS), core-level photoemission spectroscopy (CL PES), low-energy electron microscopy (LEEM), microbeam low-energy electron diffraction (μLEED), and scanning tunneling microscopy (STM). The h-BN monolayer on Fe(110) is periodically corrugated in a wavy fashion with an astonishing degree of long-range order, periodicity of 2.6 nm, and the corrugation amplitude of ∼0.8 Å. The wavy pattern results from a strong chemical bonding between h-BN and Fe in combination with a lattice mismatch in either [111] or [111] direction of the Fe(110) surface. Two primary orientations of h-BN on Fe(110) can be observed corresponding to the possible directions of lattice match between h-BN and Fe(110), with approximately equal area of the boron nitride domains of each orientation.

Complete Mitochondrial DNA Analysis of Eastern Eurasian Haplogroups Rarely Found in Populations of Northern Asia and Eastern Europe

PloS One. 2012  |  Pubmed ID: 22363811

With the aim of uncovering all of the most basal variation in the northern Asian mitochondrial DNA (mtDNA) haplogroups, we have analyzed mtDNA control region and coding region sequence variation in 98 Altaian Kazakhs from southern Siberia and 149 Barghuts from Inner Mongolia, China. Both populations exhibit the prevalence of eastern Eurasian lineages accounting for 91.9% in Barghuts and 60.2% in Altaian Kazakhs. The strong affinity of Altaian Kazakhs and populations of northern and central Asia has been revealed, reflecting both influences of central Asian inhabitants and essential genetic interaction with the Altai region indigenous populations. Statistical analyses data demonstrate a close positioning of all Mongolic-speaking populations (Mongolians, Buryats, Khamnigans, Kalmyks as well as Barghuts studied here) and Turkic-speaking Sojots, thus suggesting their origin from a common maternal ancestral gene pool. In order to achieve a thorough coverage of DNA lineages revealed in the northern Asian matrilineal gene pool, we have completely sequenced the mtDNA of 55 samples representing haplogroups R11b, B4, B5, F2, M9, M10, M11, M13, N9a and R9c1, which were pinpointed from a massive collection (over 5000 individuals) of northern and eastern Asian, as well as European control region mtDNA sequences. Applying the newly updated mtDNA tree to the previously reported northern Asian and eastern Asian mtDNA data sets has resolved the status of the poorly classified mtDNA types and allowed us to obtain the coalescence age estimates of the nodes of interest using different calibrated rates. Our findings confirm our previous conclusion that northern Asian maternal gene pool consists of predominantly post-LGM components of eastern Asian ancestry, though some genetic lineages may have a pre-LGM/LGM origin.

Medication Errors-an Enduring Problem for Children and Elderly Patients

Upsala Journal of Medical Sciences. Feb, 2012  |  Pubmed ID: 22376241

Abstract Objective. To analyze the types and reasons of medication errors, committed by health care professionals, which led to toxicological consultations at the Czech Toxicological Information Centre (TIC). Methods. Inquiries arising from medication errors for 2000-2010 were extracted and evaluated from the database of the TIC, recording the consultations of poisonings due to drugs, household products, plants, and mushrooms. Results. From a total of 44,344 calls concerning pharmaceuticals, 215 (0.5%) were denoted by the caller as medication errors; 130 involved children (90 below 5 years of age) and 85 involved adults (30-60 years of age). The most common errors were: improper dosage (60.9%), wrong medication (19.3%), or erroneous route of administration (12.9%). The most frequent medication errors appeared using drugs affecting the nervous system (psycholeptics and antiepileptics), antibiotics, and drugs affecting the respiratory system. Nurses administering the drugs were responsible for 43.0%, physicians prescribing the drugs for 36.8%, and pharmacists dispensing the drugs for 20.2% of the errors. Of 25 patients with severe drug intoxications, 60.0% were children under 5 years of age treated with pharmaceuticals affecting the CNS, and 28.0% patients over 60 years of age with chronic application of theophylline, digoxin, or lithium. Conclusions. The trend in medication errors has remained relatively stable over the past 11 years. The analysis of medication errors shows two high-risk categories: children of less than 5 years of age, in whom the dose was not correctly adjusted, and elderly people with chronic medication and insufficient control of their medication level. Therefore, the measures for risk reduction should focus primarily on them.

Characterizing the Geometry of InAs Nanowires Using Mirror Electron Microscopy

Nanotechnology. Mar, 2012  |  Pubmed ID: 22397834

Mirror electron microscopy (MEM) imaging of InAs nanowires is a non-destructive electron microscopy technique where the electrons are reflected via an applied electric field before they reach the specimen surface. However strong caustic features are observed that can be non-intuitive and difficult to relate to nanowire geometry and composition. Utilizing caustic imaging theory we can understand and interpret MEM image contrast, relating caustic image features to the properties and parameters of the nanowire. This is applied to obtain quantitative information, including the nanowire width via a through-focus series of MEM images.

The Y-chromosome C3* Star-Cluster Attributed to Genghis Khan's Descendants is Present at High Frequency in the Kerey Clan from Kazakhstan

Human Biology. Feb, 2012  |  Pubmed ID: 22452430

Abstract To verify the possibility that the Y-chromosome C3* star-cluster attributed to Genghis Khan and his patrilineal descendants is relatively frequent in the Kereys, who are the dominant clan in Kazakhstan and in Central Asia as a whole, polymorphism of the Y-chromosome was studied in Kazakhs, represented mostly by members of the Kerey clan. The Kereys showed the highest frequency (76.5%) of individuals carrying the Y-chromosome variant known as C3* star-cluster ascribed to the descendants of Genghis Khan. C3* star-cluster haplotypes were found in two subclans, Abakh-Kereys and Ashmaily-Kereys, diverged about 20-22 generations ago according to the historical data. Median network of the Kerey star-cluster haplotypes at 17 STR loci displays a bipartite structure, with two subclusters defined by the only difference at the DYS448 locus. Noteworthy is a strong correspondence of these subclusters with the Kerey subclans affiliation. The data obtained suggest that the Kerey clan appears to be the largest known clan in the world descending from a common Y-chromosome ancestor. Possible ways of Genghis Khan's relationship to the Kereys are discussed.

Complex Formation, Chemical Exchange, Species Structure, and Stereoselective Effects in the Copper(II)-L/DL-histidine Systems

Dalton Transactions (Cambridge, England : 2003). Jan, 2012  |  Pubmed ID: 22120906

The formation of copper(II) complexes with L- and DL-histidine (HisH) has been studied by means of pH-potentiometry and spectrophotometry over a wide range of pH (2-14), ligand-to-metal ratio (1 : 1-15 : 1), and temperature (15-55 °C) in aqueous solutions with 1.0 mol dm(-3) KNO(3) as background. Formation constants and spectral characteristics of 13 complex types were found. Fine stereoselective effects have been detected with preferential coordination of two ligands with identical configuration in Cu(His)(HisH)(+) and opposite configuration in Cu(His)(2). The stereoselective effect for Cu(His)(HisH)(+) is explained by hydrogen bond formation between the carboxyl and imidazolyl groups of neighboring ligands at cis-arrangement of amino groups (3N(eq)-form). The opposite sign of stereoselective effect for Cu(His)(2) is derived from favourable axial coordination of the imidazole group in meso-form with cis-structure (3N(eq)N(ax)-form). A significant tetrahedral distortion was revealed for the first time in the prevalent cis-isomer of the Cu(L-His)(2) 4N(eq)-form. These findings were confirmed by EPR data and DFT computations at the B3LYP/TZVP level. The prevalence of cis-isomers for these complexes has been assigned to the rather strong trans effect of the amino groups. The structures of other detected complexes are briefly discussed on the basis of spectroscopic data. Chemical exchange reactions in the copper(II)-L/DL-hishidine systems have been investigated by the NMR relaxation of water protons. A unique proton exchange reaction with short-term proton dissociation from the coordinated imidazolyl group catalyzed by hydroxide ion was characterised for the first time. The discovered enantioselective effects in the ligand exchange reactions between Cu(His)(2) and HisH or His(-) species were attributed to the associative substitution mechanism.