In JoVE (1)

Other Publications (93)

Articles by Richard G. Dekany in JoVE

 JoVE Engineering

Bringing the Visible Universe into Focus with Robo-AO

1Caltech Optical Observatories, California Institute of Technology, 2Department of Astronomy, California Institute of Technology, 3Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 4Inter-University Centre for Astronomy & Astrophysics, 5Observatories of the Carnegie Institution for Science, 6Benoziyo Center for Astrophysics, Weizmann Institute of Science

JoVE 50021

Other articles by Richard G. Dekany on PubMed

[New Technic of Staining of Fabrics]

Kísérletes Orvostudomány. Mar, 1955  |  Pubmed ID: 13264403

[Isotope Renography in Children with Orthostatic Proteinuria]

Orvosi Hetilap. Nov, 1969  |  Pubmed ID: 5360122

[Isotope Nephrographic Studies in Orthostatis-proteinuric Children]

Monatsschrift Für Kinderheilkunde. Aug, 1969  |  Pubmed ID: 5397060

[Successful Surgical Treatment of Internal Carotid Artery Stenosis. The Role of Physical and Instrumental Examinations in the Early Diagnosis and in the Evaluation of Progress]

Orvosi Hetilap. Feb, 1969  |  Pubmed ID: 5778996

[Primary Renal Arterial Aneurysm Causing Hypertension in a 5-year-old Child]

Orvosi Hetilap. May, 1969  |  Pubmed ID: 5793524

[Heart Sounds Imitating Mitral Stenosis in Certain Clinical Pictures]

Orvosi Hetilap. Jun, 1974  |  Pubmed ID: 4840702

[Determination of Free CPK and CPK/MB Isoenzyme in Myocardial Infarct]

Orvosi Hetilap. Feb, 1980  |  Pubmed ID: 7383681

Inactivation of Pig Muscle 3-phosphoglycerate Kinase by Thiol Modification Depends on Reagent Size

European Journal of Biochemistry / FEBS. Feb, 1984  |  Pubmed ID: 6697999

Two thiol groups (out of the total seven) of pig muscle 3-phosphoglycerate kinase can be alkylated in 0.1 M Tris/Hcl buffer, pH 7.5, at 20 degrees C either with methyl iodide or with iodoacetamide in a second-order reaction with rate constants 0.05 +/- 0.02 M-1S-1 and 0.23 +/- 0.05 M-1S-1 respectively. The slow reaction of the remaining five thiols with Ellman's reagent (Nbs2), which requires the unfolding of the protein, is not affected by the nature of the alkylating reagent. While methylation of the two reactive thiols does not affect either the specific activity of the enzyme or the Km values of the substrates, carboxamidomethylation is accompanied by the loss of enzymic activity. Both the methylated and the carboxamidomethylated enzymes bind 3-phosphoglycerate or MgATP practically with the same binding constants as the native enzyme, as detected by fluorimetric titration of enzymes complexed with 1-anilinonaphthalenesulfonate (ANS). Thus, inactivation during carboxamidomethylation cannot be due to changes in the substrate-binding ability of the enzyme. The substrate-caused changes in the fluorescence emission spectrum of ANS bound to the carboxamidomethylated enzyme are different from the changes observed with the native enzyme. The fluorescence properties of the methylated enzyme do not differ from those of the native enzyme. These differences may reflect the different mode of substrate binding to the carboxamidomethylated enzyme as compared to the native or the methylated one. Thus, the special steric requirements of the enzymic reaction are possibly not fulfilled after carboxamidomethylation. The presence of the equilibrium mixture of substrates lessens the reactivity of the fast-reacting thiols towards both alkylating agents, a finding that indicates the effects of substrates on the local conformation around these groups.

Catheter Perforation of the Heart

Cor Et Vasa. 1986  |  Pubmed ID: 3792007

Out of 11,000 cardiac catheterizations in adult patients, perforation of the heart occurred in four cases (0.036%). Left atrial wall perforation by an NIH catheter occurred in one patient without sequelae. In three patients, right ventricular perforation by a Zucker-type catheter was observed, causing pericardial tamponade. This observation may discourage angiographers from the routine use of this type of catheter.

[Sensitivity and Specificity of ECG-stress Tests in the Diagnosis of Coronary Artery Stenosis]

Orvosi Hetilap. Jan, 1986  |  Pubmed ID: 3951843

Structure of the Chicken Link Protein Gene: Exons Correlate with the Protein Domains

Proceedings of the National Academy of Sciences of the United States of America. Sep, 1987  |  Pubmed ID: 3476955

The structure of the chicken link protein gene has been determined from a series of genomic clones that cover the entire coding region as well as the complete 3'-untranslated region and a small portion of the 5'-untranslated region. The gene is greater than 80 kilobase pairs long and is present in a single copy in the chicken genome. The link protein gene contains at least five exons with four encoding the entire protein. The domain of link protein that has homologies with immunoglobulin-like proteins and the tandemly repeated hyaluronic acid binding domains are each encoded by separate exons. The exon-intron structure indicates that the link protein gene may have arisen by exon duplication and exon shuffling.

Non-invasive Assessment of Elevated Ventricular Diastolic Pressures in Patients with Ischaemic Heart Disease

Cor Et Vasa. 1987  |  Pubmed ID: 3581836

For non-invasive assessment of the diastolic pressures of both ventricles, 50 patients with ischaemic heart disease were studied by combined mechano- and echocardiography. Twenty one patients had pulmonary congestion, eleven had acute mitral regurgitation and 18 had signs of left and right heart failure. All patients had undergone cardiac catheterization. The diastolic parts of apexcardiograms (left and right ACG) and the morphological alterations of mitral and tricuspid valve echograms were analysed. Using the invasive and non-invasive data of three groups a non-invasive diastolic pressure scale for both ventricles could be construed.

Comparative Study on the Short-term Effects of Angiotensin Converting Enzyme Inhibitors (Lopirin, SQUIBB and Tensiomin), and Dihydralazine in Chronic Cardiac Failure

Acta Physiologica Hungarica. 1988  |  Pubmed ID: 3075406

The authors have compared the short-term effect of two captopril (ACE inhibitor) preparations namely the Lopirin (SQUIBB) and Tensiomin (EGIS) and dihydralazine as well as placebo in 15 patients with severe heart failure (NYHA III-IV, class). In case of 8 patients with NYHA IV, functional class the short-term effect of the combined therapy of dihydralazine and Lopirin and dihydralazine and Tensiomin as well dihydralazine and placebo have been compared. The underlying disease was dilated cardiomyopathy (DCM) and ischaemic heart disease (IHD). At the end of the treatment with different drugs and placebo the clinical signs of heart failure (complaints and physical status) and the echo and mechanocardiographic parameters of left ventricular function were assessed. The parameters, apart from the clinical signs, have been evaluated in double blind fashion. Compared to placebo all the three drugs i.e. dihydralazine, Lopirin as well as Tensiomin have decreased significantly the NYHA classes, influenced favorably the non-invasive parameters of left ventricular function and decreased blood pressure. As to the dihydralazine, it improved the left ventricular ejection function and the clinical state of the patients with DCM in a higher degree than the two ACE inhibitors did. The effect of Tensiomin and Lopirin was the same in every respect. Both have influenced more favourable the complaints and physical state of patients with IHD than dihydralazine has. The left ventricular filling pressure, the double product (heart rate x wall tension) indicating the myocardial oxygen demand were more reduced in their effect than in that of dihydralazine. Unlike dihydralazine both decreased the heart rate. Administering one of the two ACE inhibitors to the dihydralazine beneficial additive effects have been experienced; the NYHA classes, the heart rate, the left ventricular wall tension and the double product diminished. The authors, on the bases of the results, consider Tensiomin and Lopirin as equivalent in their effect. In their opinion the administration of these drugs mean a new, efficient way of therapy, first of all in cases of heart failure caused by IHD. In the most severe cases they suggest a trial with the combined dihydralazine-ACE inhibitor therapy.

The Estimation of Left Ventricular Ejection Fraction in Ischaemic Heart Disease by Polycardiographic Ways. Modification of the Antani Method

Acta Cardiologica. 1988  |  Pubmed ID: 3261072

Estimation of Left Atrial Filling Pressure by Apexcardiography, Reliability of New Parameters

Acta Cardiologica. 1990  |  Pubmed ID: 2339585

[Thrombolysis by Tissue Plasminogen Activator in Acute Myocardial Infarct]

Orvosi Hetilap. Sep, 1991  |  Pubmed ID: 1923474

The authors participated in the European multicenter investigation, ESPRIT, organized by the Wellcome Research Laboratories. Thrombolytic treatment by intravenous tissue plasminogen activator was performed in 25 patients with early (less than 6h) myocardial infarction. The efficacy of the treatment was controlled by repeat coronary arteriography at 60 minutes, at 90 minutes and at 24 hours of the tpA treatment. The infarct related artery was reperfused in 9/25 patients at 60 minutes, in 16/25 at 90 minutes and 17/18 at 24 hours. Four patients died after unsuccessful treatment or reocclusion. In two patients significant bleeding occurred at the puncture site but no transfusion was required. No other untoward effect was registered. The left ventricular function did not change significantly during the first day of infarction. It is concluded, that tpA is a safe thrombolytic agent in myocardial infarction. Its thrombolytic efficacy is similar to that of streptokinase.

The Selection of Optimal Vasodilator Drugs in Heart Failure Based on Noninvasive Parameters

Acta Cardiologica. 1991  |  Pubmed ID: 2031430

Correlations Between Maximal Exercise Capacity and Different Noninvasive Parameters of Left Ventricular Function in Dilated Cardiomyopathy

Acta Cardiologica. 1992  |  Pubmed ID: 1523903

Estimation of Left Atrial Filling Pressure in Coronary Artery Disease by Means of Apexcardiographic Parameters

Acta Cardiologica. 1992  |  Pubmed ID: 1523905

Adaptive Optics for Array Telescopes Using Piston-and-tilt Wave-front Sensing

Applied Optics. Oct, 1992  |  Pubmed ID: 20733806

A near-infrared adaptive optics system operating at approximately 50 Hz has been used to control phase errors adaptively between two mirrors of the Multiple Mirror Telescope by stabilizing the position of the interference fringe in the combined unresolved far-field image. The resultant integrated images have angular resolutions of better than 0.1 arcsec and fringe contrasts of >0.6. Measurements of wave-front tilt have confirmed the wavelength independence of image motion. These results show that interferometric sensing of phase errors, when combined with a system for sensing the wave-front tilt of the individual telescopes, will provide a means of achieving a stable diffraction-limited focus with segmented telescopes or arrays of telescopes.

[Thyroid-stimulating Hormone-secreting Pituitary Adenoma]

Orvosi Hetilap. Dec, 1994  |  Pubmed ID: 7991245

A 40-year-old male patient with a 2 years history of recurring hyperthyroidism is presented with clinical hyperthyroidism and diffuse goiter. Despite thyreostatic treatment and surgical thyroid ablation the hyperthyroidism recurred. The patient had laboratory evidence of hyperthyroidism and his serum TSH was persistently and enormously elevated (T4:214 nmol/l, T3:6.9 nmol/l, TSH:218 mIU/l)> Computed tomography and magnetic resonance imaging confirmed a pituitary mass of 7 cm in a-p diameter, with supra-, parasellar and sphenoidal extension. The pituitary adenoma was partially resected by transsphenoidal surgery, which failed to result in a substantial decrease in the serum thyrotropin level. Pituitary irradiation and a long-term somatostatin analog octreotide treatment (300-600 micrograms/die) combined with bromocriptine therapy resulted in a significant, but still incomplete suppression of thyrotropin secretion (TSH level about 15 mIU/l) and persisting mild hyperthyroidism. The size of the adenoma was unchanged during the two years of highdose octreotide treatment period. According to our best knowledge this is the first reported case of a thyrotropin-secreting pituitary adenoma in Hungary.

[The Role of Transesophageal Echocardiography in the Fibrinolytic Treatment of Thrombosis on the Artificial Mitral Valve]

Orvosi Hetilap. May, 1994  |  Pubmed ID: 8190489

Fibrinolytic treatment of mitral mechanical prosthetic valve thrombosis is still controversial. This treatment can only be justified if the incidence and severity of complications is relatively low compared to the expected success-rate. The purpose of this study was to assess the role of transesophageal echocardiography (TEE) in the selection of patients optimally suitable for fibrinolytic therapy. Five patients are reported in whom multiplane TEE revealed mitral prosthetic valve thrombosis. Two patients presented with valve obstruction, one patient with partial obstruction and earlier embolism, one with recent peripheral embolism and in 1 patient the thrombus was an unexpected finding on routine check-up. The oldest thrombus was first seen 5 months before fibrinolysis. There was no left atrial thrombus in any of patients. The thrombus was dissolved in all cases by Streptokinase given in a 200,000 unit bolus, followed by 100,000 unit per hour within 13-72 hours. The result of fibrinolysis was assessed by transthoracic echo-Doppler exam in 2 cases, by TEE in 2, and by both in 1 patient. Transient ischemic attack occurred in one case as the complication of treatment. In conclusion: the fibrinolytic treatment of mitral prosthetic valve thrombosis based on TEE findings is an effective and safe therapeutic modality.

[Prognostic Value of Exercise Parameters and Simple Non-invasive Variables of Left Ventricular Function in Dilated Cardiomyopathy]

Orvosi Hetilap. Aug, 1995  |  Pubmed ID: 7651712

Authors assessed the prognostic value of some simple, routinely used non-invasive parameters in dilated cardiomyopathy. Fifty patients, 43 male and 7 female, mean NYHA class 2.3, treated with digitalis, diuretics and vasodilators, were tested. Mean follow up time was 24 months. The evaluated parameters were as follows: maximal exercise capacity, heart rate, systolic blood pressure, as well as rate-pressure product at peak exercise, their increase during the test, fractional shortening measured by M-mode echocardiography, mean pulmonary capillary wedge pressure estimated by apexcardiography and clinical grade of heart failure (NYHA class). Exercise test was multistage, symptom limited, maximal upright bicycle ergometer test. Both one-way and multivariate analysis showed that except of fractional shortening all of the evaluated parameters related significantly to the survival. According to the one-way analysis maximal exercise capacity, rate-pressure product and systolic blood pressure at peak exercise as well as the estimated value of mean pulmonary capillary wedge pressure proved to be the strongest prognosticators. Multivariate analysis showed that the prognostic value of the rate-pressure product at peak exercise and that of the estimated mean pulmonary capillary wedge pressure proved to be additive, their combined consideration resulted in the highest accuracy of prediction.

[The Role of Echocardiography in Acute Myocardial Infarct]

Orvosi Hetilap. Mar, 1995  |  Pubmed ID: 7708387

Echocardiography performed in acute myocardial infarction helps to make the diagnosis, to detect complications of acute myocardial infarction and to choose adequate therapy. The authors evaluate the echocardiographic results of 47 patients at bedside exam. Wall motion abnormalities were revealed in 16 of 19 Q-infarct cases. Echocardiography performed in 28 suspected cases of myocardial infarction showed segmental wall motion abnormalities in 14 cases, out of them infarction was diagnosed later in 9 patient and non-Q myocardial infarction in 3 cases. Heparin was given in all cases, but thrombolysis was applied in only 9 patients. Left ventricular thrombus was found in 3 patients with anterior myocardial infarction, neither of whom had received thrombolytic therapy. The following mechanical complications were detected: free wall rupture in one patient, ventricular septal defect in three patients, early left ventricular aneurysm in one patients and right ventricular infarction in one patient. 14 patients with decreased left ventricular function were not subsequently given beta receptor blockers.

Prognostic Value of Simple Exercise Test Parameters in Patients with Dilated Cardiomyopathy

Acta Cardiologica. 1995  |  Pubmed ID: 7771174

The prognostic value of maximal exercise capacity as well as that of the simple exercise systolic blood pressure and heart rate variables were evaluated in 50 patients with dilated cardiomyopathy. Patients were treated beside digitalis and/or diuretics with vasodilators aggressively. Exercise was performed on an upright bicycle ergometer. Continuous, multistage, symptom limited, maximal tests were carried out. Patients were followed up for 23.5 +/- 15.2 months. Both one-way and multivariate analyses of data showed, that not only the maximal exercise capacity related significantly to the survival, but the several simple systolic blood pressure and heart rate variables (their values at peak exercise and their increase during the test) did so as well. Considering parameters separately, maximal exercise capacity was found the strongest predictor of survival, though the power of the calculated rate-pressure product at peak exercise, that of the systolic blood pressure at peak exercise as well as that of the increase in heart rate during the test proved nearly as strong as the maximal exercise capacity did. Anyway, the multivariate analysis showed that the former parameters were dependent on maximal exercise capacity. Some parameters with individual prognostic value proved independent from each other. Combined consideration of the systolic blood pressure at peak exercise and the increase of heart rate during exercise resulted in the highest predictive power which exceeded even the power of maximal exercise capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

The Gene Encoding the Elongation Factor P Protein is Essential for Viability and is Required for Protein Synthesis

The Journal of Biological Chemistry. Dec, 1997  |  Pubmed ID: 9405429

Elongation factor P (EFP) is a protein that stimulates the peptidyltransferase activity of fully assembled 70 S prokaryotic ribosomes and enhances the synthesis of certain dipeptides initiated by N-formylmethionine. This reaction appears conserved throughout species and is promoted in eukaryotic cells by a homologous protein, eIF5A. Here we ask whether the Escherichia coli gene encoding EFP is essential for cell viability. A kanamycin resistance (KanR) gene was inserted near the N-terminal end of the efp gene and was cloned into a plasmid, pMAK705, that has a temperature-sensitive origin of replication. After transformation into a recA+ E. coli strain, temperature-sensitive mutants were isolated, and their chromosomal DNA was sequenced. Mutants containing the efp-KanR gene in the chromosome grew at 33 degrees C only in the presence of the wild-type copy of the efp gene in the pMAK705 plasmid and were unable to grow at 44 degrees C. Incorporation of various isotopes in vivo suggests that translation is impaired in the efp mutant at 44 degrees C. At 44 degrees C, mutant cells are severely defective in peptide-bond formation. We conclude that the efp gene is essential for cell viability and is required for protein synthesis.

The Effect of Cadmium Ion Adsorption on the Growth of CdS Nanoparticles at Colloidal Silica Particle Interfaces in Binary Liquids

Journal of Colloid and Interface Science. Nov, 1997  |  Pubmed ID: 9441632

Adsorption isotherms have been determined for the binding of Cd2+ onto the surfaces of hydrophilic A200 SiO2 and hydrophobic R972 SiO2 particles dispersed in ethanol (1>)-cyclohexane (2) mixtures at ethanol mole fractions of x1 = 0.05, 0.10, 0.20, and 0.40. CdS nanoparticles have been generated in situ within the ethanolic nanoreactors at surfaces of SiO2 particles in the different ethanol-cyclohexane binary liquids by the addition of hydrogen sulfide. Absorption spectra of the CdS particles provided information on their quantity, absorption edges, optical band gaps, and mean diameters. Good correlations have been obtained between the adsorption isotherms and size of the CdS particles as well as between the adsorption isotherms and the amount of CdS formed. The smallest CdS particles (ca. 6 nm diameter) have been obtained on the surfaces of SiO2 particles dispersed in ethanol (1>)-cyclohexane (2) mixtures at ethanol mole fractions of x1 = 0.05. More CdS particles have been observed to coat the hydrophilic A200 SiO2 than the hydrophobic R972 particles. In the x1 = 0.10 ethanol (1)-cyclohexane (2) liquid mixtures up to 10% of the SiO2 surface can be covered by CdS nanoparticles. Immersion wetting enthalpy measurements in methanol established the surface of the SiO2 particles to be hydrophilic, which became partially hydrophobic upon and the binding of cadmium ions and hence upon the subsequent formation of CdS. Copyright 1997 Academic Press. Copyright 1997Academic Press

Haemangioma in the Hypopharynx: Necessity to Screen the Larynx and Hypopharynx During Upper GI Endoscopy

Endoscopy. Nov, 1997  |  Pubmed ID: 9476776

Novel Liposaccharide Conjugates for Drug and Peptide Delivery

Journal of Pharmaceutical Sciences. Jan, 1998  |  Pubmed ID: 9452964

Sugar-lipid conjugates with general structure 1-4 were prepared by coupling amino sugars with N-Boc-protected lipoamino acids and oligomers. Conjugates with general structure 5 were also prepared from glucuronic acid and methyl 2-aminohexadecanoate. The physicochemical properties of the conjugates were modified by varying the nature and number of sugars or the number of lipoamino acids or their alkyl chain length. The ability of the liposaccharides to aggregate was examined. These preliminary experiments have demonstrated the ability of the liposaccharides to form particulate systems per se and also their ability to be incorporated into conventional liposomal systems. The structure of the respective liposaccharides and the molar ratio of liposaccharide to dimyristoyl lecithin and cholesterol were found to have a profound effect on the type of colloidal systems produced.

[Experience with Percutaneous Endoscopic Gastrostomy in the Nutrition of a Patient with 3rd and 4th Degree Facial Burns]

Orvosi Hetilap. May, 1998  |  Pubmed ID: 9619045

Recovery after thermal injury depends in great proportion on nutrition. A major problem is accounted in patients with facial burn, because they can not be nourished per vias naturales. Eliminating disadvantages of parenteral nutrition, but utilizing the advantages of enteral nutrition, we have tried a new method of treatment in a patient whose case is presented. On the second day after injury a percutaneous endoscopic gastrostomy was made. On the 7th day after injury and on the 4th day from the beginning of enteral nutrition complete intake of food and liquid was assured through the percutaneous endoscopic gastrostoma. We had no complication related to the gastrostoma. Nutrition through the percutaneous endoscopic gastrostoma at our patient provided a "natural" route to assure liquid, electrolite and energy balance, prevented atrophy of intestinal mucosa and its metabolic and immunologic complications. With the use of percutaneous endoscopic gastrostoma the possible complications of central line catheter were omitted. Our opinion is that percutaneous endoscopic gastrostomy is a safe and effective method for the clinical nutrition of burned patients.

Calculation of the BET Compatible Surface Area from Any Type I Isotherms Measured Below the Critical Temperature

Journal of Colloid and Interface Science. Apr, 1999  |  Pubmed ID: 10092370

It may occur in practice that the nitrogen isotherm should be measured at 77 K only in order to determine the Brunauer-Emmett-Teller (BET) specific surface area [as(N2, 77)]. This fact has given cause for an elaborate method to calculate the value of as(N2, 77) from Type I isotherms measured on any adsorbents at any temperature. Since Type I isotherms are measured most often in practice the proposed method makes it possible to calculate the value of as(N2, 77) from isotherms of adsorptives which are the actual topics of the investigations. Thus, in these cases the determination of nitrogen isotherms at 77 K can be omitted. The proposed method is based on the Tóth (T) equation and on its modified and extended forms. In these equations are present the parameters chim, chio, and t with the following physical meanings: chim and chio are integral constants originating from the Gibbs equation integrated between definite limits of pressure and coverage and t is a parameter characterizing the heterogeneity of the adsorbents. The parameters chim and chio assure the thermodynamic consistence of these relationships. It is proven that the parameters (chim)1/t and (chio)1/t depend only on the structure of adsorbents (micro-, mezoporous, or smooth surfaces). These parameters, calculated from Type I isotherms measured under the critical temperature of the adsorptives, are the bases of the calculation of the BET compatible surface areas. Copyright 1999 Academic Press.

Separation of the First Adsorbed Layer from Others and Calculation of the BET Compatible Surface Area from Type II Isotherms

Journal of Colloid and Interface Science. Apr, 1999  |  Pubmed ID: 10092371

In the previous paper it has been proven that a BET compatible specific surface area, asc(N2, 77), can be calculated from any Type I isotherm measured below the critical temperature. In this paper it is proven that the same calculation can be performed from any Type II isotherms if the isotherm has a pure monolayer domain. In order to distinguish the mono- and multilayer adsorption the relative free energy of the surface as a function of the adsorbed amount, pir(ns), and the functions psi(pr) and psi(ns) are applied, both defined by the differential expression (ns/pr)(dpr/dns). When the multilayer adsorption becomes the dominant process then the function pir(ns) has a point of inflexion and functions psi(pr) and psi(ns) have maximum values. It has been demonstrated that in most of the Type II isotherms the mono- and multilayer domains can be separated, so the monolayer component isotherm can be calculated by the T (Tóth) equation. Therefore, it is possible to calculate the BET compatible specific surface area discussed in detail in the previous paper. It has also been proven that there are Type II isotherms which describe only multilayer adsorption; i.e., the functions psi(pr) and psi(ns) do not have maximum values. In these cases the Harkins-Jura equation should be applied. Copyright 1999 Academic Press.

Cadmium Ion Adsorption Controls the Growth of CdS Nanoparticles on Layered Montmorillonite and Calumit Surfaces

Journal of Colloid and Interface Science. May, 1999  |  Pubmed ID: 10222100

Adsorption isotherms have been determined for the intercalation of cadmium ions (Cd2+) into layered hydrophobized montmorillonite (HDP-M) and calumit (DBS-C) sheets dispersed in ethanol (1)-cyclohexane (2) mixtures. The amount of Cd2+ adsorbed depended strongly on the composition of the binary liquid; at an ethanol mole fraction of 0.05 (x1 = 0.05), 95% of the added Cd2+ is located in the ethanolic nanoreactor at the HDP-M (or DBS-C) surface. CdS nanoparticles have been generated in situ in ethanolic nanoreactors at the HDP-M and DBS-C surfaces. Absorption spectrophotometric measurements provided information on the number of CdS nanoparticles formed and on their absorption edges, bandgaps, and mean diameters. Good correlations have been obtained between the adsorption isotherms and the size (and the amount) of the CdS formed. X-ray diffractometry established that CdS nanoparticles stretched the HDP-M and DBS-C lamellas unevenly upon intercalation. Copyright 1999 Academic Press.

High Prevalence of Factor V Leiden Mutation and 20210A Prothrombin Variant in Hungary

Thrombosis and Haemostasis. Apr, 1999  |  Pubmed ID: 10235459

How the Medical System Manages Patients with Suspected or Confirmed Heart Failure in Hungary

European Journal of Heart Failure. Aug, 1999  |  Pubmed ID: 10935681

Ventriculoatrial Cross-talk Dependent Pacemaker Syndrome

Pacing and Clinical Electrophysiology : PACE. Jun, 2000  |  Pubmed ID: 10879399

A patient with dilated cardiomyopathy and DDD pacemaker experienced paroxysmal returns of her symptoms. IEGM revealed VA cross-talk resulting in functional undersensing of the following P wave that occurred during the PVARP and initiating a pacemaker syndrome with the pacemaker as a bystander.

Prediction of the Effect of Bisoprolol in Dilated Cardiomyopathy

Cardiovascular Drugs and Therapy / Sponsored by the International Society of Cardiovascular Pharmacotherapy. Oct, 2000  |  Pubmed ID: 11101203

Survival improvement by beta-blocker treatment in patients with chronic heart failure appears to be related to the intermediate-term changes in left ventricular function. The therapeutic potential of beta blockade might be increased by early identification of patients in whom left ventricular function would deteriorate. We aimed at predicting the intermediate-term effect of bisoprolol on left ventricular systolic and diastolic function in patients with dilated cardiomyopathy. Twenty-five patients with symptomatic chronic heart failure treated with bisoprolol were investigated. As a background, tailored therapy with digitalis, diuretics and vasodilators was given. Prediction of the 6-month (intermediate-term) effect of bisoprolol was investigated, using baseline values and short-term (1-month) changes of simple, noninvasive parameters obtained at rest and during maximal exercise. Multivariate analysis resulted in reliable predictions, there was close correlation between the observed and predicted changes of left atrial filling pressure (R = 0.87) and left ventricular ejection fraction (R = 0.74). The baseline value of left ventricular ejection fraction, short-term changes of the pulse amplitude and the double product proved independent predictors of intermediate-term changes of left ventricular ejection fraction. The baseline value of mean pulmonary capillary wedge pressure, heart rate, and increase in heart rate during maximal exercise were predictors of the intermediate-term changes in mean pulmonary capillary wedge pressure. In dilated cardiomyopathy, the intermediate-term effects of bisoprolol on left ventricular ejection fraction and mean pulmonary capillary wedge pressure can be predicted reliably by simple noninvasive variables in the early treatment phase.

Long-term Left Ventricular Pacing

Acta Cardiologica. Oct, 2000  |  Pubmed ID: 11103832

A 57-year-old female was implanted with a Biotronik Pikos VVI pulse generator. During her follow-up period right bundle-branch block was observed. Therefore further posteroanterior and lateral chest X-ray and echocardiography were performed. Only the transoesophageal echocardiography showed exactly the abnormal pathway of the electrode through the foramen ovale apertum to the left side of the heart. Abnormal electrode position can create serious complications, however, our patient remained free of symptoms throughout her 5 year follow-up.

Metal Ion Coordination of Macromolecular Bioligands: Formation of Zinc(II) Complex of Hyaluronic Acid

Carbohydrate Research. May, 2001  |  Pubmed ID: 11434378

The coordination of zinc(II) ion to hyaluronate (Hya), a natural copolymer, in aqueous solution at pH 6 was investigated by potentiometric and circular dichroism (CD) spectroscopic methods, and by monitoring the changes in macroscopic properties by high-precision measurements. The zinc(II)-selective electrode, and CD measurements proved the binding of zinc(II) by Hya. A number of Hya fragments (Mr approximately 3.3 x 10(3)-1.4 x 10(6)) were studied to estimate the contributions of the polyelectrolyte effect, the solvation and host-guest interactions to the extra stabilization of the macromolecular zinc(II) complexes as compared with the monomeric unit. The zinc(II) ion activity increase reflected a stability decrease for the fragments with Mr < 4 x 10(4). This molecular weight differs from that where cleavage of the Hya skeleton starts (approximately 5 x 10(5), according to the size-exclusion gel, and anion-exchange chromatographic behavior of the Hya fragments) and from that where the polyelectrolyte effect stops (approximately 6 x 10(3)). The excess volumes and Bingham shear yield values of the solutions revealed the transformation of the coherent random coil structure stabilized by intermolecular association in the NaHya to an intramolecular association producing the globular structure of the ZnHya molecule, with a smaller but more strongly bound solvate water sheet.

[Animation. Maintaining the Aging Memory]

Soins. Gérontologie. May-Jun, 2002  |  Pubmed ID: 12068688

TiO2-based Photocatalytic Degradation of 2-chlorophenol Adsorbed on Hydrophobic Clay

Environmental Science & Technology. Aug, 2002  |  Pubmed ID: 12214657

The combination of adsorption and heterogeneous photocatalysis has been investigated as a promising technology for the removal of organic water pollutants. A laboratory study of the removal and decomposition of 2-chlorophenol (2-CP) as a toxic organic pollutant was carried out under various conditions with an organophilized clay mineral (hexadecylpyridinium chloride-modified montmorillonite; HDPM) as adsorbent and Degussa P25 TiO2 as photocatalyst. Three different oxidation processes leading to the degradation of 2-CP were compared: direct photolysis, heterogeneous photocatalysis in a TiO2 suspension, and the decomposition of substrate adsorbed on HDPM in the presence of TiO2. Both the degradation of 2-CP and the formation of intermediates were analyzed by HPLC, the total organic carbon content and the total organic and inorganic chloride contents were measured to monitor the mineralization process, and X-ray diffraction and thermoanalytical measurements were made to characterize the hydrophobic clay adsorbent. The heterogeneous photocatalytic degradation of dissolved (2-CP/UV/TiO2) and desorbed 2-CP (2-CP/HDPM/UV/TiO2) appeared to be equally efficient, whereas direct photolysis of 2-CP was far less efficient in the oxidative destruction. HDPM proved to be a suitable adsorbent, capable of adsorbing toxic organics from water. It was demonstrated that the adsorbent (at relatively high concentration) did not decrease the rate of mineralization of 2-CP. The results confirmed that the adsorbent retains its structure and composition during the mineralization process, and thus it can be reused without regeneration. The combination of adsorption and heterogeneous photocatalysis studied may be an efficient and economical means of accumulating, removing, and oxidizing organic water contaminants, and its application is in accordance with the growing environmental demands.

[Formation of Crystalline Calcium Phosphate Coating on the Titanium Dioxide Layer of Dental Implants' Surface]

Fogorvosi Szemle. Oct, 2002  |  Pubmed ID: 12434709

Production of octacalcium phosphate crystals on the surface of titanium dioxide particles was achieved at high concentration of titania particles. Optimising the speed of addition of the reagents in the process of crystal growth in heterogeneous nucleation reaction led to reproducible OCP crystal structure on the particle surface. The crystal structure of OCP was investigated by SEM, XRD and FTIR methods. The same crystallization process on the surface of metallic titanium plates did not result in formation of OCP crystals. The evaporated titanium layers on a glass surface and titanium plates without excimer laser treatment did not bond calcium phosphate at any rate. SEM investigations imply that the surface layer of titanium plates changes radically due to laser beam treatment, likely because of oxidation of titanium in the process of evaporation followed by deposition back onto the surface. The calcium phosphate formation on these oxidised titanium plates could be observed by SEM. It can be concluded, that for OCP-formation on titanium metal surface it is necessary to form a thick oxide layer, as the native oxide layer in the case of non-treated titanium substrates did not bound the calcium phosphate, while formation of calcium phosphate could be reached on the laser-treated surface.

[Adsorption of Neutral Polymers on Liposomes: Investigation of the Correlation Between Liposomes and Polymers]

Acta Pharmaceutica Hungarica. 2002  |  Pubmed ID: 12494787

The characteristics of the adsorption process of neutral polymers: poly(vinyl alcohol), poly(vinyl pyrrolidone), and dextrane onto liposomes with three different lipid compositions were investigated as follows. 1 determination of the amount of polymers adsorbed on the surface of liposomes, 2 detection of the changes in the membrane structure brought by the adsorption of polymers with a high precision densimeter, 3 test dye release experiments with membrane diffusion cells after remote loading of liposomes with acridine orange (AO). The amount of polymers adsorbed on the surface of liposomes was expressed with adsorption isotherms at 25 +/- 1 degrees C. Connections were found between the lipid composition influencing the fluidity of liposome membrane, the surface charge density of liposomes, the physical-chemical properties of the polymers and the quantitative adsorption properties of the polymers. Decreasing of the molar excess volume values counted from the results of the high precision densimetric measurements revealed the compression of the membrane structure caused by polymer adsorption. We were able to influence the test dye (AO) release properties of the soy lecithin phospholipid (SLPL)/cholesterol (Chol)/dicethyl phosphate (DCP) = 25:3:2 (mol/mol) liposomes by the changing of the amount of PVA or DEX added to their dispersions.

Binary Solvent Mixture Adsorption As a Characterisation Tool to Determine the Hydrophilic/hydrophobic Properties of Multiwall Carbon Nanotubes

Chemical Communications (Cambridge, England). Nov, 2003  |  Pubmed ID: 14649841

A simple method is offered to quantitatively characterise the hydrophobic/hydrophilic properties of carbon nanotubes by measuring binary solvent mixture adsorption.

[Preparation and Structural Determination of Lyotropic Lamellar Liquid Crystalline Systems of Pharmaceutical Importance]]

Acta Pharmaceutica Hungarica. 2003  |  Pubmed ID: 14702685

Lamellar lyotropic liquid crystalline systems are thermodynamically stable, optically isotropic continuous compositions composed of particles of a few nanometeres in diameter which are formed spontaneously or with a low energy input in the definite proportions of the given components [8, 27]. New possibilities for the development of controlled drug delivery systems are inherent in these systems in consequence of their stability and special, skin friendly structure [3]. The present aim was to formulate and study two- or multicomponent compositions with a relatively low surfactant content, composed of materials official in the pharmacopoeia and suitable for therapeutic purposes. Macroscopic examination of the samples was carried out, together with polarizing light microscopy [5, 28] and transmission electron microscopic observation of replicas produced by the freeze-fractured technique [29-31] for the purpose of demonstrating the presence of lamellar liquid crystalline domains. The interlamellar repeated distance confirming the existence of a regular structure was determined by means of X-ray diffraction [26, 32].

Adam Politzer (1835-1920): His Medical Studies and Publications in Hungarian

Otology & Neurotology : Official Publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. Jan, 2004  |  Pubmed ID: 14724496

Adam Politzer was one of the most well-known otologists of the 19th century. Unfortunately, very little is known about his life during his years as a medical student and about his publications in Hungarian. The aim of this study is to summarize Politzer's student years between 1854 and 1859 and his 13 publications in Hungarian.

Comparison of Measurements of the Outer Scale of Turbulence by Three Different Techniques

Applied Optics. Apr, 2004  |  Pubmed ID: 15098834

We have made simultaneous and nearly simultaneous measurements of L0, the outer scale of turbulence, at the Palomar Observatory by using three techniques: angle-of-arrival covariance measurements with the Generalized Seeing Monitor (GSM), differential-image-motion measurements with the adaptive-optics system on the Hale 5-m telescope, and fringe speed measurements with the Palomar Testbed Interferometer (PTI). The three techniques give consistent results, an outer scale of approximately 10-20 m, despite the fact that the spatial scales of the three instruments vary from 1 m for the GSM to 100 m for the PTI.

Synthesis of ZnO Nanoparticles on a Clay Mineral Surface in Dimethyl Sulfoxide Medium

Langmuir : the ACS Journal of Surfaces and Colloids. Mar, 2004  |  Pubmed ID: 15835163

Nanocrystalline ZnO particles have been prepared with different methods using zinc cyclohexanebutyrate as precursor in dimethyl sulfoxide (DMSO) medium via alkaline hydrolysis. A series of preparations were carried out in the presence of layered silicates (kaolinite and montmorillonite). It was revealed by different measurement techniques that the presence of the clay minerals has a stabilization influence on the size of the ZnO nanocrystals. UV-vis absorption spectra show a blue shift when the nanoparticles are prepared in the presence of the clay minerals. The average particle diameters calculated from the Brus equation ranged from 2.6 to 13.0 nm. The UV-vis spectra of the synthesized nanoparticles did not show any red shift after 2-3 days, demonstrating that stable ZnO nanocrystals are present in the dispersions. The presence of the ZnO nanoparticles was also proven by fluorescence measurements. A number of the nanoparticles are incorporated into the interlamellar space of the clays, and an intercalated structure is formed as proven by X-ray diffraction (XRD) measurements. The size of the nanoparticles in the interlamellar space is in the range of 1-2 nm according to the XRD patterns. Transmission electron microscopy and high-resolution transmission electron microscopy investigations were applied to determine directly the particle size and the size distribution of the nanoparticles.

Fast Wave-front Reconstruction by Solving the Sylvester Equation with the Alternating Direction Implicit Method

Optics Express. Jul, 2004  |  Pubmed ID: 19483853

Large degree-of-freedom real-time adaptive optics (AO) control requires reconstruction algorithms that are computationally efficient and readily parallelized for hardware implementation. In particular, we find the wave-front reconstruction for the Hudgin and Fried geometry can be cast into a form of the well-known Sylvester equation using the Kronecker product properties of matrices. We derive the filters and inverse filtering formulas for wave-front reconstruction in two-dimensional (2-D) Discrete Cosine Transform (DCT) domain for these two geometries using the Hadamard product concept of matrices and the principle of separable variables. We introduce a recursive filtering (RF) method for the wave-front reconstruction on an annular aperture, in which, an imbedding step is used to convert an annular-aperture wave-front reconstruction into a squareaperture wave-front reconstruction, and then solving the Hudgin geometry problem on the square aperture. We apply the Alternating Direction Implicit (ADI) method to this imbedding step of the RF algorithm, to efficiently solve the annular-aperture wave-front reconstruction problem at cost of order of the number of degrees of freedom, O(n). Moreover, the ADI method is better suited for parallel implementation and we describe a practical real-time implementation for AO systems of order 3,000 actuators.

Large-scale Wave-front Reconstruction for Adaptive Optics Systems by Use of a Recursive Filtering Algorithm

Applied Optics. May, 2005  |  Pubmed ID: 15881072

We propose a new recursive filtering algorithm for wave-front reconstruction in a large-scale adaptive optics system. An embedding step is used in this recursive filtering algorithm to permit fast methods to be used for wave-front reconstruction on an annular aperture. This embedding step can be used alone with a direct residual error updating procedure or used with the preconditioned conjugate-gradient method as a preconditioning step. We derive the Hudgin and Fried filters for spectral-domain filtering, using the eigenvalue decomposition method. Using Monte Carlo simulations, we compare the performance of discrete Fourier transform domain filtering, discrete cosine transform domain filtering, multigrid, and alternative-direction-implicit methods in the embedding step of the recursive filtering algorithm. We also simulate the performance of this recursive filtering in a closed-loop adaptive optics system.

Adsorption on Hydrophobized Surfaces: Clusters and Self-organization

Advances in Colloid and Interface Science. Jun, 2005  |  Pubmed ID: 15936292

The arrangement of liquid molecules on surfaces bristling with alkyl chains is deduced from adsorption studies, X-ray powder diffraction data, and microcalorimetric measurements of swelling-type layered materials, especially clay minerals. Small polar molecules such as water, ethanol, formamide, dimethylsulfoxide, and aromatic compounds are clustered between the alkyl chains pointing away from the surface. The energetic contribution related to the movement of the alkyl chains from direct contact with the surface atoms into upright positions is decisive. The importance of the interactions between the liquid molecules on the structure of the adsorption layer is clearly indicated by the changes of the adsorption layer thickness by salt addition. Thermodynamic data are obtained from surface excess adsorption isotherms from binary liquid mixtures combined with microcalorimetric measurements. Long-chain adsorptives such as long-chain alcohols interact with the surface alkyl chains by forming stable bimolecular films. These films undergo a series of higher-order phase transitions into kink- and gauche-block structures as the consequence of rotational isomerization of the alkyl chains. Such transitions are considered elementary processes in self-assembling films (layer-by-layer deposition, fuzzy films, Langmuir-Blodgett technique), and lipid membranes.

Development of Otorhinolaryngology (ORL) in Hungary Between 1880 and 1920

The Journal of Laryngology and Otology. Supplement. Aug, 2005  |  Pubmed ID: 16101060

Deep Impact: Observations from a Worldwide Earth-based Campaign

Science (New York, N.Y.). Oct, 2005  |  Pubmed ID: 16150977

On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass to gas mass in the ejecta was much larger than before impact; (iii) the new activity did not last more than a few days, and by 9 July the comet's behavior was indistinguishable from its pre-impact behavior; and (iv) there were interesting transient phenomena that may be correlated with cratering physics.

Structural Characterization of Self-assembled Polypeptide Films on Titanium and Glass Surfaces by Atomic Force Microscopy

Biomacromolecules. Nov-Dec, 2005  |  Pubmed ID: 16283764

Chemically modified biomaterial surfaces (titanium and glass) covered with polyelectrolyte self-assembled films formed by the alternating adsorption of cationic poly-L-lysine (PLL) and anionic poly-L-glutamic acid (PGA) were structurally characterized by atomic force microscopy. Complementary information concerning the thickness and layer-by-layer growth of the films was provided by optical waveguide light-mode spectroscopy. The frequently used ex situ and the rarely used in situ build-up methods were compared. Important aspects of the industrial applicability of these films, their stability in time, and possible differences in their morphology were investigated. The films revealed a granular pattern, with grain diameters of 270 +/- 87 nm for glass (up to 8 bilayers) and 303 +/- 89 nm for titanium (up to 10 bilayers), independently of the build-up procedure. Both surfaces displayed a rehydration capability, the titanium surface exhibiting a better stability in time. The high roughness values observed at acidic or basic pH are related to the degree of ionization of PGA and PLL.

Characterization of Polypyrrole-silver Nanocomposites Prepared in the Presence of Different Dopants

The Journal of Physical Chemistry. B. Sep, 2005  |  Pubmed ID: 16853234

Conducting polypyrrole (PPy) powder synthesized by using FeCl3 x 6 H2O and/or Fe(NO3)3 oxidants was impregnated in silver salt solutions. The stability and decomposition of the material was followed by thermogravimetric measurements. The total silver content was determined by atom absorption spectroscopy (ICP-AAS). The heat and electric conductivities of the composites were measured and correlated with the silver content. The incorporated silver was speciated and measured by X-ray diffraction (XRD). The spectra proved that the chemical state of the silver incorporated into the composite depends on the anion used in the polymerization process. In the case of the polymerization in a nitrate ion containing solution, the impregnation leads exclusively to the formation of metallic silver. The size distribution of the AgCl and Ag nanoparticles, determined from transmission electron microscopy (TEM) pictures in the different composites, proves the formation of a rather uniform species below 10 and 7 nm, respectively. The observations can be correlated with the different interactions in the PPy-chloride/nitrate-silver systems. The redox type interaction based conclusions can be considered as a guide during the preparation of other metal-conducting polymer composites.

Antioxidant Status of Interval-trained Athletes in Various Sports

International Journal of Sports Medicine. Feb, 2006  |  Pubmed ID: 16475056

Muscular exercise results in an increased production of free radicals and other forms of reactive oxygen species (ROS). Further, developing evidence implicates cytotoxins as an underlying etiology of exercise-induced stimuli in muscle redox status, which could result in muscle fatigue and/or injury. Two major classes of endogenous protective mechanisms (enzymatic and nonenzymatic antioxidants) work together to reduce the harmful effects of oxidants in the cell. This study examined the effects of acute physical exercise on the enzymatic antioxidant systems of different athletes and comparison was made to the mechanism of action of three main antioxidant enzymes in the blood. Handball players (n = 6), water-polo players (n = 20), hockey players (n = 22), basketball players (n = 24), and a sedentary control group (n = 10 female and n = 9 male) served as the subjects of this study. The athletes were divided into two groups according to the observed changes of activity of superoxide dismutase enzyme. The antioxidant enzyme systems were characterized by catalase (CAT), glutathione-peroxidase (GPX), and superoxide-dismutase (SOD) and measured by spectrophotometry. An important finding in the present investigation is that when the activities of SOD increased, the activities of GPX and CAT increased also and this finding related to the physical status of interval-trained athletes. Positive correlation between SOD and GPX activities was observed (r = 0.38 females, r = 0.56 males; p < 0.05). We have observed that the changes in the primary antioxidant enzyme systems of athletes are sport specific, and different from control subjects. Presumably, with interval-trained athletes, hydrogen-peroxide is significantly eliminated by glutathione-peroxidase. From these results it can be concluded that the blood redox status should be taken into consideration when establishing a fitness level for individual athletes.

Secondary Structure Dependent Self-assembly of Beta-peptides into Nanosized Fibrils and Membranes

Angewandte Chemie (International Ed. in English). Apr, 2006  |  Pubmed ID: 16526070

Synthesis of 1,4-anhydro-D-fructose and 1,4-anhydro-D-tagatose

Carbohydrate Research. Jul, 2006  |  Pubmed ID: 16603137

1,4-Anhydro-D-fructose and 1,4-anhydro-D-tagatose were prepared from 1,2-O-isopropylidene-D-glucofuranose via the common intermediate 3,5,6-tri-O-benzyl-D-glucitol. The title compounds may be interesting anti-oxidants and feature activities akin to their natural pyranoid counterpart, 1,5-anhydro-D-fructose.

The Role of Insertion Allele of Angiotensin Converting Enzyme Gene in Higher Endurance Efficiency and Some Aspects of Pathophysiological and Drug Effects

Current Medicinal Chemistry. 2006  |  Pubmed ID: 16918342

None of the genetic markers are selectively associated with elite athletes, but potential candidates are found in the renin-angiotensin system, which plays a key role in the regulation of cardiovascular physiology. The most extensively examined gene in connection with the hemodynamics category is the angiotensin converting enzyme (ACE). This review paper has focused on ACE I/D allele polymorphism regarding the evidence of the effects of physiological and pathophysiological drugs and has completed with an original work in the exercise physiology.

Thallium-201 Myocardial SPECT in Left Bundle Branch Block: Diagnosis of Myocardial Ischemia with a Disease-specific Reference Database

Journal of Nuclear Cardiology : Official Publication of the American Society of Nuclear Cardiology. Jul, 2006  |  Pubmed ID: 16919576

The aim of this study was to assess the value of a myocardial perfusion single photon emission computed tomography (SPECT) reference file for patients with left bundle branch block (LBBB).

Synthesis and Stabilization of Prussian Blue Nanoparticles and Application for Sensors

Journal of Colloid and Interface Science. May, 2007  |  Pubmed ID: 17350030

Prussian blue (PB) nanoparticles were synthesized by two methods from FeCl2 and K3Fe(CN)6 and from FeCl3 and K3Fe(CN)6 based on the method published by Fiorito et al., and stabilized by different polymers like polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyallylamine hydrochloride (PAH), polydiallyl-dimethyldiammonium chloride (PDDA) and polystyrene sulfonate (PSS). The effect of the monomer/Fe3+ ratio was studied regarding the average particle size and zeta-potential. The forming PB structure was checked by X-ray diffraction. The stabilization was successful for every applied polymer, but the average particle size significantly differs. Particle size distributions were determined by Malvern type nanosizer equipment and by transmission electron microscope (TEM) and zeta potential values were determined for the obtained stabile samples. The results revealed that by using FeCl2 and K3Fe(CN)6 for PB preparation particles with narrow size distribution and average diameter of 1.7 nm occurred but stabilization was necessary. By the other method the dispersion was stabile with 182 nm particles but the particle size exponentially decreased to 18 nm with increasing PVP concentration. Ultrathin nanofilms were prepared on glass support by the alternating layer-by-layer (LbL) method from PB particles and PAH. The morphology of the prepared films was investigated also by AFM. The films were immobilized on interdigitated microsensor electrodes (IME) and tested in sensing hydrogen peroxide and different acids like acetic acid, hydrochloric acid vapors.

Neuroscience Letters. May, 2007  |  Pubmed ID: 17367929

1,5-anhydro-D-fructose from D-fructose

Carbohydrate Research. Jul, 2007  |  Pubmed ID: 17368437

1,5-anhydro-D-fructose was efficiently prepared from D-fructose via regiospecific 1,5-anhydro ring formation of 2,3-O-isopropylidene-1-O-methyl(tolyl)sulfonyl-D-fructopyranose and subsequent deprotection.

Photocatalytic Oxidation of Organic Pollutants on Titania-clay Composites

Chemosphere. Jan, 2008  |  Pubmed ID: 17698167

TiO2/Ca-montmorillonite composites were prepared by wet grinding in an agate mill. Positively charged TiO2 nanoparticles are bound to the surface of the negatively charged montmorillonite layers via heterocoagulation; the clay mineral is used as adsorbent and support for the photooxidation process. Aquatic solution of 0.5mM phenol was degraded by irradiation with UV-VIS light (lambda=250-440 and 540-590 nm) in suspensions of TiO2-clay composites and significant photodegradation was observed at 40-60% TiO2/Ca-montmorillonite compositions. Synergistic effect was detected at solid/liquid interface for degradation of phenol and at solid/gas interface in the recycling flow reactors for photooxidation of ethanol and toluene vapors.

Formulation of an Intermediate Product from Human Serum Albumin for the Production of a Solid Dosage Form

European Journal of Pharmaceutics and Biopharmaceutics : Official Journal of Arbeitsgemeinschaft Für Pharmazeutische Verfahrenstechnik E.V. Mar, 2008  |  Pubmed ID: 17870448

The main objective of this study was to evaluate and to increase the processibility of a model protein (human serum albumin (HSA)) for preparation of an intermediate for a solid dosage form. The applicability of the solid forms is easier, and therefore their formulation is a promising method for the application of proteins. The layering of powdered cellulose with HSA solutions of different concentrations in a fluid bed apparatus with the top spray method was applied. The yield of this technique was very good, independently of the concentration of the applied solution. The HSA covered the particles (the HSA layer formed was smooth), but it caused aggregation of the cellulose particles, and spray-dried microparticles also formed. The proportion of optimum-sized particles (200-315 microm) decreased. The largest amount was detected for the samples prepared with liquid containing 15% HSA (about 2 times higher than the second best). Not only the size, but also the shape of the particles was changed. The alteration in this parameter caused a change in the flowability. This was likewise the best for the samples prepared with the liquid containing 15% HSA. The concentration of HSA in the fraction containing smaller particles was higher, because of the abrasion of the particles and the enrichment of the spray-dried HSA. The distribution of HSA in the large particles was uneven. The layering of powder cellulose can be applied to produce an intermediate from HSA for solid dosage forms, but the appropriate concentration of this protein solution must be optimized previously because HSA can act as a binder. The formation of large agglomerates must be eliminated, because the distribution of the active agent in these is very inhomogeneous. The present results indicated that the best value can be achieved with liquid containing between 12.5% (most homogeneous distribution of HSA) and 15% HSA (best flowability).

The Efficacy of Alum-containing Ferrous Thermal Water in the Management of Chronic Inflammatory Gynaecological Disorders--a Randomized Controlled Study

European Journal of Obstetrics, Gynecology, and Reproductive Biology. Oct, 2008  |  Pubmed ID: 18511175

Treatment of gynaecological disorders is a frequent, but only barely substantiated application of balneotherapy. This study investigated potential differences between the clinical symptoms, pelvic blood flow and specific laboratory parameters of patients undergoing balneotherapy with two different types of immersion: alum-containing and tap water.

Magnetically Modified Single and Turbostratic Stacked Graphenes from Tris(2,2'-bipyridyl) Iron(II) Ion-exchanged Graphite Oxide

The Journal of Physical Chemistry. B. Nov, 2008  |  Pubmed ID: 18680337

Loading of graphite oxide (GO) with tris(2,2'-bipyridyl) iron(II) ions and subsequent calcination affords a novel graphene-based composite with magnetic and electrically conductive properties. The pH of the starting aqueous suspension and the washing procedure play a crucial role in the successful immobilization of the iron precursor, which is mainly governed by ion exchange. The complex is intercalated between the graphene oxide layers, where it adopts a distorted conformation. Rapid heating of this solid results in the deflagration of GO and the formation of ultrafine ( d = 2-14 nm) Fe2O3 particles with maghemite as the dominant phase. The superparamagnetic maghemite crystals are dispersed uniformly in the high-surface-area diamagnetic matrix built up from single or turbostratic stacked graphenes.

Colossal Pressure-induced Lattice Expansion of Graphite Oxide in the Presence of Water

Angewandte Chemie (International Ed. in English). 2008  |  Pubmed ID: 18814163

Study of a MEMS-based Shack-Hartmann Wavefront Sensor with Adjustable Pupil Sampling for Astronomical Adaptive Optics

Applied Optics. Oct, 2008  |  Pubmed ID: 18830305

We introduce a Shack-Hartmann wavefront sensor for adaptive optics that enables dynamic control of the spatial sampling of an incoming wavefront using a segmented mirror microelectrical mechanical systems (MEMS) device. Unlike a conventional lenslet array, subapertures are defined by either segments or groups of segments of a mirror array, with the ability to change spatial pupil sampling arbitrarily by redefining the segment grouping. Control over the spatial sampling of the wavefront allows for the minimization of wavefront reconstruction error for different intensities of guide source and different atmospheric conditions, which in turn maximizes an adaptive optics system's delivered Strehl ratio. Requirements for the MEMS devices needed in this Shack-Hartmann wavefront sensor are also presented.

The Antibacterial Substance Taurolidine Exhibits Anti-neoplastic Action Based on a Mixed Type of Programmed Cell Death

Autophagy. Feb, 2009  |  Pubmed ID: 19066471

The antibacterial amino-acid derivative taurolidine (TAU) has been recently shown to exhibit anti-neoplastic activity based on a mechanism, which is still unknown in detail. Cytotoxicity and clonogenic assays were performed and the impact of apoptosis modulators, a radical scavenger, autophagy inhibitors, silencing of apoptosis inducing actor (AIF) and cytochrome-c (Cyt-C) by siRNA, and knockdown of autophagy related genes were evaluated in vitro. The intracellular ATP-content, release of AIF and Cyt-C, and DNA-laddering were investigated. This study could demonstrate cell killing, inhibition of proliferation, and inhibition or prevention of colony formation in human glioma cell lines and ex vivo glioblastoma cells after incubation with TAU. This effect is based on the induction of a mixed type of programmed cell death with the main preference of autophagy, and involvement of senescence, necroptosis and necrosis. This mechanism of action may open a new approach for therapeutic intervention.

Structural, Optical, and Adsorption Properties of ZnO(2)/poly(acrylic Acid) Hybrid Thin Porous Films Prepared by Ionic Strength Controlled Layer-by-layer Method

Journal of Colloid and Interface Science. Apr, 2009  |  Pubmed ID: 19162274

ZnO(2)/poly(acrylic acid) sandwich structures were prepared by layer-by-layer (LbL) self-assembly. The structure and optical behavior of the hybrid films were controlled by changing the surface charge and conformation of the poly(acrylic acid). The buildup of the films was followed by UV-vis absorption and reflection spectroscopy, atomic force microscopy (AFM), X-ray diffraction (XRD), and quartz crystal microbalance (QCM) measurements. It was found that the ionic strength of the polymer solution had a great influence on the film thickness which, in turn, affected the optical properties. The water vapor adsorption isotherms of the films determined by QCM showed an adsorption hysteresis characteristic of porous thin layer structures. The adsorption of water molecules inside the films changed the effective refractive index resulting in a change of the reflection properties. This phenomenon is shown to be exploited for the application of the films as optical sensors. The polarizability of water molecules in the adsorption layer was also determined. It was found that polarization of water molecules in the adsorption layer is much lower than in the liquid water when the surface coverage (Theta) is low.

Synthesis of 4-O-glycosylated 1,5-anhydro-D-fructose and of 1,5-anhydro-D-tagatose from a Common Intermediate 2,3-O-isopropylidene-D-fructose

Carbohydrate Research. May, 2009  |  Pubmed ID: 19349042

Four novel disaccharides of glycosylated 1,5-anhydro-D-ketoses have been prepared: 1,5-anhydro-4-O-beta-D-glucopyranosyl-D-fructose, 1,5-anhydro-4-O-beta-D-galactopyranosyl-D-fructose, 1,5-anhydro-4-O-beta-D-glucopyranosyl-D-tagatose, and 1,5-anhydro-4-O-beta-D-galactopyranosyl-D-tagatose. The common intermediate, 1,5-anhydro-2,3-O-isopropylidene-beta-D-fructopyranose, was prepared from D-fructose and was converted into the D-tagatose derivative by oxidation followed by stereoselective reduction to the 4-epimer. The anhydroketoses thus prepared were glycosylated and deprotected to give the disaccharides.

Comparative Solution and Solid-phase Glycosylations Toward a Disaccharide Library

Carbohydrate Research. Aug, 2009  |  Pubmed ID: 19410240

A comparative study on solution-phase and solid-phase oligosaccharide synthesis was performed. A 16-member library containing all regioisomers of Glc-Glc, Glc-Gal, Gal-Glc, and Gal-Gal disaccharides was synthesized both in solution and on solid phase. The various reaction conditions for different approaches and corresponding yields are analyzed and discussed.

Solid-phase Random Glycosylation

Journal of Combinatorial Chemistry. Sep-Oct, 2009  |  Pubmed ID: 19663453

Two different approaches were employed to study solid phase random glycosylations to obtain oligosaccharide libraries. In approach I, Wang resin esters were attached to the acceptors structures. Following their glycosylation and resin cleavage, the peracetylated components of the oligosaccharide libraries were characterized. In approach II, polymer-linked donor components could be employed and processed correspondingly. Approach I proved to be superior regarding yield and versatility of products and also allowed the formation of higher oligomers.

Acrylamide, Acrylic Acid and N-isopropylacrylamide Hydrogels As Osmotic Tissue Expanders

Skin Pharmacology and Physiology. 2009  |  Pubmed ID: 19786824

Osmotically active tissue expanders allow the harvesting of soft tissue for reconstruction after different injuries. However, their expansion properties could be improved. Thus, our goal was to examine the in vivo applicability of acrylamide (AAm), acrylic acid (AAc) and N- isopropylacrylamide (NIPAAm) hydrogels.

In Vitro Pharmacology of Inosine, with Special Reference to Possible Interactions with Capsaicin-sensitive Mechanisms and Inflammatory Mediators

Methods and Findings in Experimental and Clinical Pharmacology. Jul-Aug, 2009  |  Pubmed ID: 19798450

The in vitro pharmacology of inosine (Ino), a putative anti-inflammatory compound, has been investigated in smooth muscle preparations, with emphasis on its possible interaction with known inflammatory mediators, as well as capsaicin, an inducer of "neurogenic inflammation". The highest concentration of Ino routinely studied was 1 mM, since 10 mM nonspecifically inhibited many types of smooth muscle motor responses. In the guinea pig isolated ileum or trachea, Ino (1 mM) failed to influence the excitatory effect of capsaicin. The nitric oxide (NO)-mediated relaxant effect of capsaicin in the human colonic circular muscle was not influenced by Ino. Ino only weakly reduced the contractile effect of histamine on the guinea pig ileum. Substance P-mediated nonadrenergic, noncholinergic (NANC) contractions evoked by electrical stimulation in the guinea pig ileum were inhibited by half by Ino (1 mM). Ino showed no or only a weak inhibitory effect on NANC relaxation of the rat ileum. Arachidonic acid- or leukotriene D(4)-induced contractions of the guinea pig ileum were only moderately inhibited by Ino. Collectively, these results indicate that Ino (up to 1 mM) shows no major antagonist activity at histamine H(1) receptors, leukotriene CysLT(1) receptors, the transient receptor potential channel TRPV1 or tachykinin NK(1) or NK(2) receptors, or cyclooxygenase-inhibitory activity. Therefore, its anti-inflammatory activity is probably not associated with these mechanisms. The in vitro methods used in this study are capable of detecting a wide range of biological effects and hence may be recommended as a screening procedure for potential drugs or natural products.

Pressure-induced Insertion of Liquid Alcohols into Graphite Oxide Structure

Journal of the American Chemical Society. Dec, 2009  |  Pubmed ID: 19947629

Graphite oxide (GO) immersed in an excess of methanol and ethanol media is found to undergo a phase transformation at about 0.2-0.8 GPa, with an expansion of the unit cell volume by approximately 40%, due to pressure-induced insertion of solvent into interlayer space. The pressure at which the structural expansion occurs does not correlate with the solidification pressure of the alcohol, in contrast to the graphite oxide/water system. The expanded high-pressure phase of GO/ethanol could be quenched back to ambient pressure. Compression of graphite oxide with a 2:1 water/methanol medium revealed a complex anomaly with two steps attributed to insertion of methanol and water at different pressure points.

[Investigation of Surgical Applicability of Acryl-based Tissue Expanders]

Magyar Sebészet. Feb, 2010  |  Pubmed ID: 20156789

Hydrogels made of acrylamide (AAm), acrylic acid (AAc) and N-isopropylacrylamide (NIPAAm) display outstanding ability of swelling in vitro and this property can be influenced by the composition of the polymers. Our objective was to study the in vivo behavior of hydrogels made of acrylics and their potential role in surgery.

Hydrophobization of Bovine Serum Albumin with Cationic Surfactants with Different Hydrophobic Chain Length

Colloids and Surfaces. B, Biointerfaces. Aug, 2010  |  Pubmed ID: 20417078

The interaction between bovine serum albumin (BSA) and cationic surfactants with different chain length was investigated. The hydrodynamic diameters, electrokinetic potentials, as well as the fluorescence emission properties of the protein-surfactant complexes with different hydrophobic character were studied. Dynamic light scattering was applied to determine how the size and electrokinetic potential of the protein aggregates changes due to surfactant loading. It was found that by increasing the chain length of the surfactant the required amount of the surfactant for total aggregation of the system is decreased dramatically, which means that in the course on the aggregation process hydrophobic effects should be considered and it was further proved with fluorescence emission intensity measurements. By changing the pH of the protein solution the contribution of the electrostatic interactions to the aggregation processes was studied. It was showed that both hydrophobic and electrostatic interactions are present in the protein-cationic surfactant interaction.

Optical and Structural Properties of Protein/gold Hybrid Bio-nanofilms Prepared by Layer-by-layer Method

Colloids and Surfaces. B, Biointerfaces. Aug, 2010  |  Pubmed ID: 20451360

Lysozyme/gold thin layers were prepared by layer-by-layer (LbL) self-assembly method. The build-up of the films was followed by UV-vis-absorbance spectra, quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) techniques. The structural property of films was examined by X-ray diffraction (XRD) measurements, while their morphology was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). It was found that gold nanoparticles (NPs) had cubic crystalline structure, the primary particles form aggregates in the thin layer due to the presence of lysozyme molecules. The UV-vis measurements prove change in particle size while the colour of the film changes from wine-red to blue. The layer thickness of films was determined using the above methods and the loose, porous structure of the films explains the difference in the results. The vapour adsorption property of hybrid layers was also studied by QCM using different saturated vapours and ammonia gas. The lysozyme/Au films were most sensitive for ammonia gas among the tested gases/vapours due to the strongest interaction between the functional groups of the protein.

Functionalization of Gold Nanoparticles with Amino Acid, Beta-amyloid Peptides and Fragment

Colloids and Surfaces. B, Biointerfaces. Nov, 2010  |  Pubmed ID: 20674288

Gold nanoparticles (Au NPs) were functionalized by cysteine (Cys), beta-amyloid peptides (Cys(0)Abeta(1-28), Cys(0)Abeta(1-40), Abeta(1-42)) and a pentapeptide fragment (Leu-Pro-Phe-Phe-Asp-OH (LPFFD-OH)). Optical absorption spectra of these systems were recorded and the plasmon resonance maximum values (lambda(max)) of the UV-vis spectra together with the transmission electron microscopy (TEM) images were also analysed. Both TEM images and the appearance of a new absorption band between approximately 720 and 750 nm in the visible spectra of the Au-cysteine and Au-LPFFD-OH systems most probably indicate that upon addition of these molecules to Au NPs-containing aqueous dispersions formation of aggregates is occurred. The wavelength shift between the two observed absorption bands in cysteine- and pentapeptide-modified Au NPs systems are Deltalambda=185 and 193 nm, respectively. These results suggest that the monodisperse spherical gold nanoparticles were arranged to chained structure due to the effect of these molecules. For confirmation of the binding of citrate and cysteine onto the plasmonic metal surface (1)H NMR measurements were also performed. (1)H NMR results may suggest that the citrate layer on the metal surface is replaced by cysteine leading to a formation of organic double layer structure. In the presence of beta-amyloid peptides the aggregation was not observed, especially in the Au-Cys(0)Abeta(1-40) and Au-Abeta(1-42) systems, however compared to the cysteine or LPFFD-OH-containing gold dispersion with Cys(0)Abeta(1-28) measurable less aggregation were occurred. The spectral parameters clearly suggest that Abeta(1-42) can attach or bind to the surface of gold nanoparticles via both the apolar and the N-donors containing side-chains of amino acids and no aggregation in the colloidal gold dispersion was observed.

Unexpected Insensitivity of the Cholinergic Motor Responses to Morphine in the Human Small Intestine

Pharmacology. 2010  |  Pubmed ID: 20699630

morphine is known to inhibit cholinergic contractions of the guinea pig small intestine. This has been compared to the human small intestinal innervated longitudinal muscle in the current study.

Stabilisation of SWNTs by Alkyl-sulfate Chitosan Derivatives of Different Molecular Weight: Towards the Preparation of Hybrids with Anticoagulant Properties

Nanoscale. Mar, 2011  |  Pubmed ID: 21258715

We have previously demonstrated that chitosan derivative N-octyl-O-sulfate chitosan (NOSC), which presents important pharmacological properties, can suspend single walled carbon nanotubes (SWNTs) up to 20 times more effectively than other chitosan derivatives in an aqueous environment. In an attempt to further investigate the impact of different molecular weights of chitosan to the solubilization and anticoagulant properties of these hybrids an array of NOSC derivatives varying their molecular weight (low, medium and high respectively) was synthesised and characterised by means of FT-IR spectroscopy, NMR spectroscopy and thermal gravimetric analysis (TGA). Microwave and nitric acid purified SWNTs, characterised by FT-IR spectroscopy, transmission electron microscopy (TEM) and Raman spectroscopy, were colloidally stabilised by these polymers and their anticoagulant activity was assessed. The results revealed that the low molecular weight NOSC coated SWNTs exhibit the highest activity when 0.5 mg mL(-1) NOSC solutions are used, activity which is similar to that of the free polymer. Preliminary studies by exposure of these hybrids to Brine Shrimp (Artemia) cysts revealed no effect on the viability of sub-adult Artemia. Our findings suggest the possibility of tailoring these nanomaterials to bear the required properties for application as biocompatible building blocks for nanodevices including biosensors and biomaterials.

Determining Air-water Exchange, Spatial and Temporal Trends of Freely Dissolved PAHs in an Urban Estuary Using Passive Polyethylene Samplers

Environmental Science & Technology. Apr, 2011  |  Pubmed ID: 21351793

Passive polyethylene (PE) samplers were deployed at six locations within Narragansett Bay (RI, USA) to determine sources and trends of freely dissolved and gas-phase polycyclic aromatic hydrocarbons (PAHs) from May to November 2006. Freely dissolved aqueous concentrations of PAHs were dominated by fluoranthene, pyrene, and phenanthrene, at concentrations ranging from tens to thousands of pg/L. These were also the dominant PAHs in the gas phase, at hundreds to thousands of pg/m3. All stations mostly followed the same temporal trends, with highest concentrations (up to 7300 pg/L for sum PAHs) during the second of 11 deployments, coinciding with a major rainstorm. Strong correlations of sum PAHs with river flows and wastewater treatment plant discharges highlighted the importance of rainfall in mobilizing PAHs from a combination of runoff and atmospheric washout. PAH concentrations declined through consecutive deployments III to V, which could be explained by an exponential decay due to flushing with cleaner ocean water during tides. The estimated residence time (tres) of the PAH pulse was 24 days, close to an earlier estimate of tres of 26 days for freshwater in the Bay. Air-water exchange gradients indicated net volatilization of most PAHs closest to Providence. Further south in the Bay, gradients had changed to mostly net uptake of the more volatile PAHs, but net volatilization for the less volatile PAHs. Based on characteristic PAH ratios, freely dissolved PAHs at most sites originated from the combustion of fossil fuels; only two sites were at times affected by fuel spill-derived PAHs.

Hydrogen-poor Superluminous Stellar Explosions

Nature. Jun, 2011  |  Pubmed ID: 21654747

Supernovae are stellar explosions driven by gravitational or thermonuclear energy that is observed as electromagnetic radiation emitted over weeks or more. In all known supernovae, this radiation comes from internal energy deposited in the outflowing ejecta by one or more of the following processes: radioactive decay of freshly synthesized elements (typically (56)Ni), the explosion shock in the envelope of a supergiant star, and interaction between the debris and slowly moving, hydrogen-rich circumstellar material. Here we report observations of a class of luminous supernovae whose properties cannot be explained by any of these processes. The class includes four new supernovae that we have discovered and two previously unexplained events (SN 2005ap and SCP 06F6) that we can now identify as members of the same class. These supernovae are all about ten times brighter than most type Ia supernova, do not show any trace of hydrogen, emit significant ultraviolet flux for extended periods of time and have late-time decay rates that are inconsistent with radioactivity. Our data require that the observed radiation be emitted by hydrogen-free material distributed over a large radius (∼10(15) centimetres) and expanding at high speeds (>10(4) kilometres per second). These long-lived, ultraviolet-luminous events can be observed out to redshifts z > 4.

Ecdysteroids from Polypodium Vulgare L

Steroids. Dec, 2011  |  Pubmed ID: 21803067

Three new compounds (3, 7, and 11) together with eight known phytoecdysteroids (1, 2, 4-6, and 8-10) were isolated from the rhizomes of common polypody, Polypodium vulgare L. The structures of compounds were elucidated by spectroscopic methods including 1D and 2D NMR measurements. The (1)H and (13)C NMR assignments of compounds 1, 6, 9 and 10 are included.

Preparation and Properties of Nanoscale Containers for Biomedical Application in Drug Delivery: Preliminary Studies with Kynurenic Acid

Journal of Neural Transmission (Vienna, Austria : 1996). Feb, 2012  |  Pubmed ID: 22065206

The main purpose of this study was to facilitate the delivery of kynurenic acid (KYNA) across the blood-brain barrier (BBB) by applying micelles as nanoscale containers. Non-ionic amphiphilic molecules were used for preparation of spherical micelles for delivery of kynurenic acid in aqueous solution in physiological condition. It was established that Triton X 100 and Lutensol AP 20 non-ionic surfactants are able to produce stable nanocontainers for delivery of kynurenic acid molecules. The incorporation of KYNA molecules was investigated by dynamic light scattering and the size of micelles were calculated between 5 and 10 nm in 150 mM NaCl and pH 7.5-7.6 solutions. Encapsulated kynurenic acid showed a significantly higher blood-brain barrier permeability compared with non-encapsulated kynurenic acid. The in vivo experiments showed that the encapsulated kynurenic acid is able to display effects within the central nervous system, even after its peripheral administration.

Introduction to the Symposium

Advances in Nutrition (Bethesda, Md.). May, 2012  |  Pubmed ID: 22585915

Hydrothermal Synthesis and Humidity Sensing Property of ZnO Nanostructures and ZnO-In(OH)3 Nanocomposites

Journal of Colloid and Interface Science. Jul, 2012  |  Pubmed ID: 22587905

Prism- and raspberry-like ZnO nanoparticles and ZnO-In(OH)(3) nanocomposites were prepared by template free hydrothermal method. XRD investigations and microscopic studies showed that pill-like In(OH)(3) particles with body-centered cubic crystal structure formed on the surface of ZnO nanoparticles resulting in increased specific surface area. TEM-EDX mapping images demonstrated that not only nanocomposite formation took place in the course of the synthesis, but zinc ions were also built into the crystal lattice of the In(OH)(3). However, only undoped In(OH)(3) was found on the surface of the pill-like particle aggregates by XPS analyses. The raspberry- and prism-like ZnO particles exhibit strong visible emission with a maximum at 585 and 595 nm, respectively, whose intensity significantly increase due to nanocomposite formation. Photoelectric investigations revealed that photocurrent intensity decreased with increasing indium ion concentration during UV light excitation, which was explained by increase in visible fluorescence emission. QCM measurements showed that morphology of ZnO and concentration of In(OH)(3) had an influence on the water vapor sensing properties.

Novel Ecdysteroids from Serratula Wolffii

TheScientificWorldJournal. 2012  |  Pubmed ID: 22645442

Two new and one known ecdysteroids were identified in the methanolic extract of the roots of Serratula wolffii. The new compounds isolated were ponasterone A-22-apioside (1) and 3-epi-shidasterone (3), together with the known 3-epi-22-deoxy-20-hydroxyecdysone (2). The structures of compounds 1-3 were determined by extensive spectroscopic techniques, including one- and two-dimensional NMR methods.

Effect of PH on Stability and Plasmonic Properties of Cysteine-functionalized Silver Nanoparticle Dispersion

Colloids and Surfaces. B, Biointerfaces. Oct, 2012  |  Pubmed ID: 22652358

Citrate-stabilized spherical silver nanoparticles (Ag NPs) with d=8.25±1.25 nm diameter were prepared and functionalized with L-cysteine (Cys) in aqueous dispersion. The nanosilver-cysteine interactions have been investigated by Raman and (1)H NMR spectroscopy. The effect of pH on stability of biofunctionalized Ag NPs was investigated. The cysteine-capped nanosilver dispersions remain stable at higher pH (pH>7), while the degree of aggregation increased as the pH decreased. Below pH ~7, the characteristic surface plasmon band of bare silver nanoparticles was back-shifted from λ(measured)(bareAgNP)=391 nm to λ(measured)(1)=387-391 nm, while the presence of a new band at λ(measured)(2)=550-600 nm was also observed depending on pH. Finite element method (FEM) was applied to numerically compute the absorption spectra of aqueous dispersions containing bare and cysteine-functionalized Ag NPs at different pH. Both the dynamic light scattering (DLS) measurements, Zeta potential values and the transmission electron microscopic (TEM) images confirmed our supposition. Namely, electrostatic interaction arose between the deprotonated carboxylate (COO(-)) and protonated amino groups (NH(3)(+)) of the amino acid resulting in cross-linking network of the Ag NPs between pH ~3 and 7. If the pH is measurable lower than ~3, parallel with the protonation of citrate and L-cysteine molecules the connection of the particles via l-cysteine is partly decomposed resulting in decrease of second plasmon band intensity.

The Contractile Effect of Anandamide in the Guinea-Pig Small Intestine is Mediated by Prostanoids but Not TRPV1 Receptors or Capsaicin-Sensitive Nerves

Basic & Clinical Pharmacology & Toxicology. Dec, 2012  |  Pubmed ID: 23216932

Although exogenous and endogenous cannabinoid receptor agonists have well-documented inhibitory effects on gastrointestinal motility, a TRPV1 receptor-mediated excitatory action of anandamide (arachidonoyl ethanolamide, AEA) in the guinea-pig ileum strip has also been described. We used in vitro capsaicin desensitization for assessing the possible participation of sensory neurons in the contractile effect of anandamide on the guinea-pig whole ileum, as well as autonomic drugs and a cyclooxygenase inhibitor for characterizing this response. Isolated organ experiments were used with isotonic recording. Contractions induced by anandamide (1 or 10 μM) were strongly inhibited by tetrodotoxin, indomethacin or atropine plus a tachykinin NK(1) receptor antagonist, but weakly to moderately reduced by atropine alone and partly diminished by the fatty acid amide hydrolase inhibitor URB 597. Neither capsaicin pre-treatment nor the TRPV1 receptor antagonist BCTC, the ganglionic blocking drug hexamethonium or cannabinoid (CB(1) or CB(2) ) receptor antagonists, influenced the effect of anandamide. It is concluded that the capsaicin-insensitive, neuronal excitatory effect of anandamide in the intestine is most probably mediated by cyclooxygenase products. Such a mechanism may also play a role at other sites in the mammalian body.

Comparative Study of the Kinetics and Equilibrium of Phenol Biosorption on Immobilized White-rot Fungus Phanerochaete Chrysosporium from Aqueous Solution

Colloids and Surfaces. B, Biointerfaces. Mar, 2013  |  Pubmed ID: 23247265

In this study the kinetics and equilibrium of phenol biosorption were studied from aqueous solution using batch technique at an initial pH of 5.5. The biosorption was studied on Ca-alginate beads, on non-living mycelial pellets of Phanerochaete chrysosporium immobilized on Ca-alginate, and on free fungal biomass. Ph. chrysosporium was grown in a liquid medium containing mineral and vitamin materials with complex composition. The biosorption process followed pseudo second-order kinetics on all bioadsorbents. The bioadsorption-equilibrium on blank Ca-alginate, free and immobilized fungal biomass can be described by Langmuir, anti-Langmuir and Freundlich isotherm models using nonlinear least-squares estimation.

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