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Find video protocols related to scientific articles indexed in Pubmed.
Molecular charge transfer by adsorbing TCNQ/TTF molecules via ?-? interaction: a simple and effective strategy to modulate the electronic and magnetic behaviors of zigzag SiC nanoribbons.
Phys Chem Chem Phys
PUBLISHED: 11-20-2014
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By means of first-principles computations, we first propose a simple and effective strategy through the molecular charge transfer via noncovalent ?-? interaction to modulate the electronic and magnetic properties of zigzag SiC nanoribbons (zSiCNRs). This charge transfer is induced by adsorbing the electron-withdrawing/donating tetracyanoquinodimethane (TCNQ) or tetrathiafulvalene (TTF) molecules on the surface of the pristine zSiCNR. It is revealed that all the TCNQ- and TTF-modified zSiCNR-systems can exhibit considerable adsorption energies in the range from -137.2 to -184.0 kJ mol(-1) and from -71.3 to -76.9 kJ mol(-1), respectively, indicating that these zSiCNR-complexes possess high structure stabilities. This kind of a molecular charge transfer via ?-? interaction can break the magnetic degeneracy of zSiCNRs, and the sole ferromagnetic (FM) metallicity and even antiferromagnetic (AFM) half-metallicity can be achieved. These intriguing findings will be advantageous for promoting SiC-based nanomaterials in the application of spintronics and multifunctional nanodevices in the near future.
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Space-bound optical source for satellite-ground decoy-state quantum key distribution.
Opt Express
PUBLISHED: 11-18-2014
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Satellite-ground quantum key distribution has embarked on the stage of engineering implementation, and a global quantum-secured network is imminent in the foreseeable future. As one payload of the quantum-science satellite which will be ready before the end of 2015, we report our recent work of the space-bound decoy-state optical source. Specialized 850 nm laser diodes have been manufactured and the integrated optical source has gotten accomplished based on these LDs. The weak coherent pulses produced by our optical source feature a high clock rate of 100 MHz, intensity stability of 99.5%, high polarization fidelity of 99.7% and phase randomization. A series of space environment tests have been conducted to verify the optical source's performance and the results are satisfactory. The emulated final secure keys are about 120 kbits during one usable pass of the low Earth orbit satellite. This work takes a significant step forward towards satellite-ground QKD and the global quantum-secured network.
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[The significance of non invasive cardiac output monitoring system on evaluating circulatory and respiratory function in pig with acute respiratory distress syndrome].
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue
PUBLISHED: 11-18-2014
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To investigate the effect of non invasive cardiac output monitoring (NICO) system in pig model with acute respiratory distress syndrome (ARDS), and to provide experimental basis for clinical application.
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[Risk factors of the occurence and death of acute respiratory distress syndrome: a prospective multicenter cohort study].
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue
PUBLISHED: 11-18-2014
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To explore the risk factors of the occurence and 28-day death of acute respiratory distress syndrome (ARDS) in intensive care unit (ICU).
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Co-transplantation of Hematopoietic Stem Cells and Cxcr4 Gene-Transduced Mesenchymal Stem Cells Promotes Hematopoiesis.
Cell Biochem. Biophys.
PUBLISHED: 11-14-2014
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Mesenchymal stem cells (MSCs) are a promising candidate for cellular therapies. Co-transplantation of MSCs and hematopoietic stem cells (HSCs) promotes successful engraftment and improves hematopoietic recovery. In this study, the effects of co-transplantation of HSCs and mouse bone marrow (BM)-derived MSCs overexpressing CXCR4 (CXCR4-MSC) on CXCR4-MSC homing capacity and the reconstitution potential in lethally irradiated mice were evaluated. Recovery of donor-derived peripheral blood leukocytes and platelets was accelerated when CXCR4-MSCs were co-transplanted with BM cells. The frequency of c-kit(+)Sca(+)Lin(-) HSCs was higher in recipient BM following co-transplantation of CXCR4-MSCs compared with the EGFP-MSC control and the BMT only groups. Surprisingly, the rate of early engraftment of donor-derived BM cells in recipients co-transplanted with CXCR4-MSCs was slightly lower than in the absence of MSCs on day 7. Moreover, co-transplantation of CXCR4-MSCs regulated the balance of T helper cells subsets. Hematopoietic tissue reconstitution was evaluated by histopathological analysis of BM and spleen. Co-transplantation of CXCR4-MSCs was shown to promote the recovery of hematopoietic organs. These findings indicate that co-transplantation of CXCR4-MSCs promotes the early phase of hematopoietic recovery and sustained hematopoiesis.
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Unusual role of epilayer-substrate interactions in determining orientational relations in van der Waals epitaxy.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 11-12-2014
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Using selected-area low-energy electron diffraction analysis, we showed strict orientational alignment of monolayer hexagonal boron nitride (h-BN) crystallites with Cu(100) surface lattices of Cu foil substrates during atmospheric pressure chemical vapor deposition. In sharp contrast, the graphene-Cu(100) system is well-known to assume a wide range of rotations despite graphene's crystallographic similarity to h-BN. Our density functional theory calculations uncovered the origin of this surprising difference: The crystallite orientation is determined during nucleation by interactions between the cluster's edges and the substrate. Unlike the weaker B- and N-Cu interactions, strong C-Cu interactions rearrange surface Cu atoms, resulting in the aligned geometry not being a distinct minimum in total energy. The discovery made in this specific case runs counter to the conventional wisdom that strong epilayer-substrate interactions enhance orientational alignment in epitaxy and sheds light on the factors that determine orientational relation in van der Waals epitaxy of 2D materials.
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Selective oral ROCK2 inhibitor down-regulates IL-21 and IL-17 secretion in human T cells via STAT3-dependent mechanism.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 11-12-2014
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Rho-associated kinase 2 (ROCK2) regulates the secretion of proinflammatory cytokines and the development of autoimmunity in mice. Data from a phase 1 clinical trial demonstrate that oral administration of KD025, a selective ROCK2 inhibitor, to healthy human subjects down-regulates the ability of T cells to secrete IL-21 and IL-17 by 90% and 60%, respectively, but not IFN-? in response to T-cell receptor stimulation in vitro. Pharmacological inhibition with KD025 or siRNA-mediated inhibition of ROCK2, but not ROCK1, significantly diminished STAT3 phosphorylation and binding to IL-17 and IL-21 promoters and reduced IFN regulatory factor 4 and nuclear hormone RAR-related orphan receptor ?t protein levels in T cells derived from healthy subjects or rheumatoid arthritis patients. Simultaneously, treatment with KD025 also promotes the suppressive function of regulatory T cells through up-regulation of STAT5 phosphorylation and positive regulation of forkhead box p3 expression. The administration of KD025 in vivo down-regulates the progression of collagen-induced arthritis in mice via targeting of the Th17-mediated pathway. Thus, ROCK2 signaling appears to be instrumental in regulating the balance between proinflammatory and regulatory T-cell subsets. Targeting of ROCK2 in man may therefore restore disrupted immune homeostasis and have a role in the treatment of autoimmunity.
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Tobacco smoking strengthens the association of elevated blood pressure with arterial stiffness: the Bogalusa Heart Study.
J. Hypertens.
PUBLISHED: 11-08-2014
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The study assessed the hypothesis that smoking strengthens the association of adult arterial stiffness with long-term cumulative burden of blood pressure (BP) from childhood to adulthood.
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Rhizobium yantingense sp. nov., a mineral-weathering bacterium.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 11-08-2014
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A Gram negative, rod-shaped bacterial strain, H66T, was isolated from the surfaces of weathered rock (purple siltstone) which was found in Yanting, Sichuan Province of China. Cells of strain H66T were motile with peritrichous flagella. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain H66T belongs to the genus Rhizobium. It closely relates to Rhizobium huautlense SO2T (98.1 %), Rhizobium alkalisoli CCBAU 01393T (98.0 %), and Rhizobium cellulosilyticum ALA10B2T (98.0 %). Analysis of housekeeping genes recA, glnII and atpD showed low levels of sequence similarity (<92.0 %) between strain H66T and other recognized Rhizobium species. The predominant components of cellular fatty acids were summed feature 8 (C18:1 ?7c and/or C18:1 ?6c) and C16:0. The G + C content of strain H66T was 60.3 mol%. Strain H66T is described as a novel species of the genus Rhizobium based on the low level of DNA-DNA relatedness (ranging from 14.3 % to 40.0 %) to these type strains of species of the genus Rhizobium and unique phenotypic characteristics. The name Rhizobium yantingense sp. nov. is proposed for this novel species. The type strain is H66T (=CCTCCAB 2014007T= LMG 28229T).
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Racial diversity of actionable mutations in non-small cell lung cancer.
J Thorac Oncol
PUBLISHED: 11-08-2014
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Lung cancer is the leading cause of cancer-related deaths in the United States. The reasons for higher incidence and poorer survival rates among black compared to white lung cancer patients have not been defined. We hypothesized that differential incidence of somatic cancer gene mutations may be a contributing factor. Previous genomic studies of non-small cell lung cancer (NSCLC) have not adequately represented black patients.
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[Adult Sturge-Weber syndrome without facial hemangioma?report of one case].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 11-06-2014
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Sturge-Weber syndrome (SWS) is characterized by angiomas affecting the ophthalmic division of the trigeminal nerve, epilepsy, intellectual impairment, hemiplegia and glaucoma. We report a patient who developed SWS without facial hemangioma (SWS type ?) in his adulthood. The patient presented with repeated episodes of headache since age 37 year. He manifested first attack of seizure at the age 47 year followed by aphasia and right upper limb palsy. Brain CT scan revealed right parietal-occipital calcification, brain CT angiography showed right temporal lobe and occipital lobe vascular malformation, and MRI showed leptomeningeal enhancement in the riht cerebral piamater. The seizure was controlled with antiepileptic drugs and reviewed in routine follow up.
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A cobalt-nitrogen complex on N-doped three-dimensional graphene framework as a highly efficient electrocatalyst for oxygen reduction reaction.
Nanoscale
PUBLISHED: 11-04-2014
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The high cost and limited natural abundance of platinum hinder its widespread applications as the oxygen reduction reaction (ORR) electrocatalyst for fuel cells. Carbon-supported materials containing metals such as Fe or Co as well as nitrogen have been proposed to reduce the cost without obvious lowering the performance compared to Pt-based electrocatalysts. In this work, based on the pyrolyzed corrin structure of vitamin B12 on the simultaneously reduced graphene support (g-VB12), we construct an efficient oxygen reduction electrocatalyst with very positive half-wave potential (only ?30 mV deviation from Pt/C), high selectivity (electron transfer number close to 4) and excellent durability (only 11 mV shift of the half-wave potential after 10?000 potential cycles). The admirable performance of this electrocatalyst can be attributed to the homogeneous distribution of abundant Co-Nx active sites, and a well-defined three-dimensional mesoporous structure of the N-doped graphene support. The high activity and long-term stability of the low cost g-VB12 make it a promising ORR electrocatalyst in alkaline fuel cells.
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In vitro fermentation of lactulose by human gut bacteria.
J. Agric. Food Chem.
PUBLISHED: 11-03-2014
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Lactulose has been known as a prebiotic that can selectively stimulate the growth of beneficial bifidobacteria and lactobacilli. Recent studies have indicated that Streptococcus mutans, Clostridium perfringens, and Faecalibacterium prausnitzii are also able to utilize lactulose. However, the previous studies mainly focused on the utilization of lactulose by individual strains, and few studies were designed to identify the species that could utilize lactulose among gut microbiota. This study aimed to identify lactulose-metabolizing bacteria in the human gut, using in silico and traditional culture methods. The prediction results suggested that genes for the transporters and glycosidases of lactulose are well distributed in the genomes of 222 of 453 strains of gastrointestinal-tract bacteria. The screening assays identified 35 species with the ability to utilize lactulose, of which Cronobacter sakazakii, Enterococcus faecium, Klebsiella pneumoniae, and Pseudomonas putida were reported for the first time to be capable of utilizing lactulose. In addition, significant correlations between lactulose and galactooligosaccharide metabolism were found. Thus, more attention should be paid to bacteria besides bifidobacteria and lactobacilli to further investigate the relationship between functional oligosaccharides and gut bacteria.
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iPro54-PseKNC: a sequence-based predictor for identifying sigma-54 promoters in prokaryote with pseudo k-tuple nucleotide composition.
Nucleic Acids Res.
PUBLISHED: 11-02-2014
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The ?(54) promoters are unique in prokaryotic genome and responsible for transcripting carbon and nitrogen-related genes. With the avalanche of genome sequences generated in the postgenomic age, it is highly desired to develop automated methods for rapidly and effectively identifying the ?(54) promoters. Here, a predictor called 'iPro54-PseKNC' was developed. In the predictor, the samples of DNA sequences were formulated by a novel feature vector called 'pseudo k-tuple nucleotide composition', which was further optimized by the incremental feature selection procedure. The performance of iPro54-PseKNC was examined by the rigorous jackknife cross-validation tests on a stringent benchmark data set. As a user-friendly web-server, iPro54-PseKNC is freely accessible at http://lin.uestc.edu.cn/server/iPro54-PseKNC. For the convenience of the vast majority of experimental scientists, a step-by-step protocol guide was provided on how to use the web-server to get the desired results without the need to follow the complicated mathematics that were presented in this paper just for its integrity. Meanwhile, we also discovered through an in-depth statistical analysis that the distribution of distances between the transcription start sites and the translation initiation sites were governed by the gamma distribution, which may provide a fundamental physical principle for studying the ?(54) promoters.
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Luminescence of La0.2Y1.8O3 nanostructured scintillators.
Opt Lett
PUBLISHED: 11-01-2014
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For the first time, transparent La0.2Y1.8O3 nanostructured polycrystalline scintillators were fabricated by sintering nanoparticle powders at high temperatures and their scintillation properties are reported. La0.2Y1.8O3 is a host material that has never been investigated as scintillators for radiation detection. Our observations found that La0.2Y1.8O3 has an intense scintillation luminescence, a detection efficiency higher than that of YAG:Ce and a comparable energy resolution to NaI and CsI scintillators. In addition, La0.2Y1.8O3 is stable and has luminescence decay lifetime in the picosecond range which is favorable for radiation detection. The luminescence of La0.2Y1.8O3 has a large Stokes-shift and a large emission bandwidth, and the luminescence is highly temperature dependent. Different from most doped scintillators, the luminescence of La0.2Y1.8O3 is most likely from the self-trapped excitons. The discovery of La0.2Y1.8O3 scintillators opens a new door for the research of new materials for radiation detection.
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Laminar Shear Stress Inhibits Endothelial Cell Metabolism via Krüppel-Like Factor 2-Mediated Repression of 6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase-3.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 11-01-2014
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Cellular metabolism was recently shown to regulate endothelial cell phenotype profoundly. Whether the atheroprotective biomechanical stimulus elicited by laminar shear stress modulates endothelial cell metabolism is not known.
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Citrate-capped platinum nanoparticle as a smart probe for ultrasensitive mercury sensing.
Anal. Chem.
PUBLISHED: 10-27-2014
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An easily prepared platinum nanoparticle (PtNP) probe for the sensitive and selective detection of Hg(2+) ions is developed here. The PtNPs with an average size of approximately 2.5 nm were prepared by a reduction method with sodium borohydride and trisodium citrate serving as reductant and stabilizer, respectively. The resulting PtNPs could catalyze the reduction of Hg(2+) by surface-capping citrate. The effect of Hg(2+) uptake implies amalgam formation, which leads to remarkable inhibition of the peroxidase-like activity of citrate-capped PtNPs. On the basis of this effect, a colorimetric mercury sensor was established through the use of citrate-capped PtNPs to catalyze the colorimetric system of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2. The high specificity of the Hg-Pt interaction provides the excellent selectivity for Hg(2+) over interfering metal ions. The sensitivity of this smart probe to Hg(2+) is extremely excellent with a limit of detection (LOD) as low as 8.5 pM. In view of these advantages, as well as the cost-effectiveness, minimized working steps, and naked-eye observation, we expect that this colorimetric sensor will be a promising candidate for the field detection of toxic Hg(2+) ions in environmental, biological, and food samples.
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[Effect of lentiviral vector mediated CXCR4 gene overexpressed mesenchymal stem cell on the protection of mice against graft-versus-host disease].
Zhonghua Xue Ye Xue Za Zhi
PUBLISHED: 10-24-2014
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To investigate the effect of the lentiviral vector mediated CXCR4 overexpressed mesenchymal stem cell (MSCs) on graft-versus-host disease (GVHD).
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Current Evidence on the Association between rs3757318 of C6orf97 and Breast Cancer Risk: a Meta-Analysis.
Asian Pac. J. Cancer Prev.
PUBLISHED: 10-24-2014
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A common genetic variant rs3757318, located in intron of C6orf97, was firstly identified to be associated with breast cancer (BC) risk by a genome-wide association (GWA) study. However, subsequent validation studies with different ethnicities have yielded conflicting results.
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[Establishment of mouse mesenchymal stem cells overexpressing CXCR4 gene and evaluation of their functions].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 10-24-2014
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This study was purposed to establish the mesenchymal stem cells (MSCs) stably overexpressing mouse CXC chemokine receptor type 4 (CXCR4) gene and to explore their function. The recombinant lentiviral vector LV-CXCR4-IRES-EGFP with packaging plasmid pSPAX2 and envelope plasmid pMD.2G were co-transfected into 293FT packaging cell line using lipofectamine 2000 to produce the recombinant lentiviral vectors. The recombinant viruses were harvested and concentrated by using ultracentrifugation. Mouse bone marrow MSC were infected with the viral supernatants. Variable methods were used to optimize the transduction condition. EGFP expression was visualized using fluorescence microscope and efficiency of infection was determined by flow cytometry (FCM). Proliferation and apoptosis were detected by proliferation curve and FCM, respectively. Migration capacity was assessed by a chemotaxis assay using transwell. Expression of EGFP were detected by fluorescence microscopy in MSCs after infection. The results showed that through optimization of infection condition, the recombination lentiviral vectors had higher infection efficacy; after infection for 72 h, the higher expression of EGFP could be observed under fluorescence microscope; the expression of CXCR4 protein on MSC surface in CXCR4-MSC group significantly increased compared with those in the control group. Meanwhile, over-expression of CXCR4 had no effect on their capacity of proliferation and did not induce apoptosis. Moreover, CXCR4 enhanced the migration of cells in the transwell induced by SDF-1 gradient compared with the EGFP control group. It is concluded that the lentiviral vector can not only infect mouse MSCs efficiently, but also can make CXCR4 express stably in MSC.
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A Novel Anaerobic Electrochemical Membrane Bioreactor (AnEMBR) with Conductive Hollow-fiber Membrane for Treatment of Low-Organic Strength Solutions.
Environ. Sci. Technol.
PUBLISHED: 10-22-2014
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A new anaerobic treatment system that combined a microbial electrolysis cell (MEC) with membrane filtration using electrically conductive, porous, nickel-based hollow-fiber membranes (Ni-HFMs) was developed to treat low organic strength solution and recover energy in the form of biogas. This new system is called an anaerobic electrochemical membrane bioreactor (AnEMBR). The Ni-HFM served the dual function as the cathode for hydrogen evolution reaction (HER) and the membrane for filtration of the effluent. The AnEMBR system was operated for 70 days with synthetic acetate solution having a chemical oxygen demand (COD) of 320 mg/L. Removal of COD was >95% at all applied voltages tested. Up to 71% of the substrate energy was recovered at an applied voltage of 0.7 V as methane rich biogas (83% CH4; < 1% H2) due to biological conversion of the hydrogen evolved at the cathode to methane. A combination of factors (hydrogen bubble formation, low cathode potential and localized high pH at the cathode surface) contributed to reduced membrane fouling in the AnEMBR compared to the control reactor (open circuit voltage). The net energy required to operate the AnEMBR system at an applied voltage of 0.7 V was significantly less (0.27 kWh/m(3)) than that typically needed for wastewater treatment using aerobic membrane bioreactors (1-2 kWh/m(3)).
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Low threshold mid-infrared supercontinuum generation in short fluoride-chalcogenide multimaterial fibers.
Opt Express
PUBLISHED: 10-17-2014
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Mid-infrared supercontinuum generation (SCG) is mostly studied in fluoride glass fibers in which long fibers and high power pump sources are needed. Taking advantages of high nonlinearity and transparency, chalcogenide glass is also applied for SCG in mid-infrared region, where specific strategy is needed to compensate large normal material dispersion. We investigate multimaterial fibers (MMFs) combined with fluoride and chalcogenide glasses for SCG. The high refraction contrast allows the zero dispersion point of the fiber to shift to below 2 ?m without air holes. These two materials have similar glass transition temperatures and thermal expansion coefficients. They are possible to be drawn together. Both step-index MMFs and microstructured MMFs (MS-MMFs) are considered. The chromatic dispersions and supercontinuum spectra are studied. A 20 dB bandwidth of over one octave SCG with high coherence can be obtained from a 1 cm MS-MMF at 1.95 ?m with a pumping peak power of 175 W. As the pump power increased, the spectrum can extend to 5 ?m. In this scheme the fiber is so short that the high level of loss, which is the feature of MMFs, will not cause problems.
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Field and long-term demonstration of a wide area quantum key distribution network.
Opt Express
PUBLISHED: 10-17-2014
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A wide area quantum key distribution (QKD) network deployed on communication infrastructures provided by China Mobile Ltd. is demonstrated. Three cities and two metropolitan area QKD networks were linked up to form the Hefei-Chaohu-Wuhu wide area QKD network with over 150 kilometers coverage area, in which Hefei metropolitan area QKD network was a typical full-mesh core network to offer all-to-all interconnections, and Wuhu metropolitan area QKD network was a representative quantum access network with point-to-multipoint configuration. The whole wide area QKD network ran for more than 5000 hours, from 21 December 2011 to 19 July 2012, and part of the network stopped until last December. To adapt to the complex and volatile field environment, the Faraday-Michelson QKD system with several stability measures was adopted when we designed QKD devices. Through standardized design of QKD devices, resolution of symmetry problem of QKD devices, and seamless switching in dynamic QKD network, we realized the effective integration between point-to-point QKD techniques and networking schemes.
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Relationship between Sucrose Metabolism and Anthocyanin Biosynthesis During Ripening in Chinese Bayberry Fruit.
J. Agric. Food Chem.
PUBLISHED: 10-15-2014
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Two cultivars of Chinese bayberry fruit cvs 'Dongkui' and 'Biqi' with five different ripening stages were used to investigate the relationship between anthocyanin biosynthesis and sugar metabolism during fruit development. The results showed that anthocynin accumulated with the increased ripening stage in both of the two cultivars of bayberries. As compared to 'Biqi' fruit, a higher level of anthocyanin content was observed in 'Dongkui' fruit due to the increased expression of anthocyanin biosynthetic and regulatory genes especially MrCHI, MrDFR1, MrANS, and MrMYB1. Meanwhile, 'Dongkui' fruit also experienced higher levels of soluble sugars including sucrose, glucose, and fructose and expression of genes such as MrSPS1, MrSPS2, MrSPS3, MrINV1, MrINV2, and MrINV3 involved in sugar metabolism. Correlation analysis showed anthocyanin content had a significant relationship with all the three soluble sugars in bayberry fruit. Therefore, our results suggested that the higher anthocyanin content in 'Dongkui' fruit might be associated with its increased levels of soluble sugars.
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Vascular Endothelial Growth Factor Accelerates Establishment of a Model of Hepatic Metastasis in Walker-256 Tumor-Bearing Rats.
Am. J. Med. Sci.
PUBLISHED: 10-14-2014
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Animal models of secondary liver cancer are limited by the time required for the development of hepatic metastases. The authors administered vascular endothelial growth factor (VEGF) to stimulate tumor growth in a model of hepatic metastasis.
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Recent development and application of constant pH molecular dynamics.
Mol Simul
PUBLISHED: 10-14-2014
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Solution pH is a critical environmental factor for chemical and biological processes. Over the last decade, significant efforts have been made in the development of constant pH molecular dynamics (pHMD) techniques for gaining detailed insights into pH-coupled dynamical phenomena. In this article we review the advancement of this field in the past five years, placing a special emphasis on the development of the all-atom continuous pHMD technique. We discuss various applications, including the prediction of pK a shifts for proteins, nucleic acids and surfactant assemblies, elucidation of pH-dependent population shifts, protein-protein and protein-RNA binding, as well as the mechanisms of pH-dependent self-assembly and phase transitions of surfactants and peptides. We also discuss future directions for the further improvement of the pHMD techniques.
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Correlation of Macular Choroidal Thickness with Concentrations of Aqueous Vascular Endothelial Growth Factor in High Myopia.
Curr. Eye Res.
PUBLISHED: 10-10-2014
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Abstract Purpose: To investigate the association of both aqueous and serum vascular endothelial growth factor (VEGF) levels and macular choroidal thickness in high myopia. Materials and methods: VEGF concentrations were measured in aqueous and serum samples via enzyme-linked immunosorbent assay (ELISA) and compared between high myopia (n?=?36 eyes, 36 patients) and normal control (n?=?42 eyes, 42 patients) eyes. Macular choroidal thickness, the distance from the retinal pigment epithelium (RPE) to the scleral interface, was determined via enhanced depth-imaging optical coherence tomography (EDI-OCT). Axial length was measured using the intraocular (IOL) lens Master. Results: Aqueous levels of VEGF from high myopia patients were significantly lower compared with those from control persons (61.4?±?27.6 versus 122.6?±?52.4?pg/ml; p?
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Two-dimensional inverse opal hydrogel for pH sensing.
Analyst
PUBLISHED: 10-09-2014
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A novel hydrogel film with a highly ordered macropore monolayer on its surface was prepared by templated photo-polymerization of hydrogel monomers on a two-dimensional (2D) polystyrene colloidal array. The 2D inverse opal hydrogel has prominent advantages over traditional three-dimensional (3D) inverse opal hydrogels. First, the formation of the 2D array template through a self-assembly method is considerably faster and simpler. Second, the stable ordering structure of the 2D array template makes it easier to introduce the polymerization solution into the template. Third, a simple measurement, a Debye diffraction ring, is utilized to characterize the neighboring pore spacing of the 2D inverse opal hydrogel. Acrylic acid was copolymerized into the hydrogel; thus, the hydrogel responded to pH through volume change, which resulted from the formation of the Donnan potential. The 2D inverse opal hydrogel showed that the neighboring pore spacing increased by about 150 nm and diffracted color red-shifted from blue to red as the pH increased from pH 2 to 7. In addition, the pH response kinetics and ionic strength effect of this 2D mesoporous polymer film were also investigated.
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Stereoselective Synthesis of ?-Linked 2-Deoxy Glycosides Enabled by Visible-Light-Mediated Reductive Deiodination.
Chemistry
PUBLISHED: 10-03-2014
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2-Deoxy sugars and their derivatives occur abundantly in many pharmaceutically important natural products. However, the construction of specific 2-deoxy-glycosidic bonds remains as a challenge. Herein, we report an efficient way to prepare 2-deoxy-?-glycosides by glycosylation of 2-iodo-glycosyl acetate and subsequent visible-light-mediated tin-free reductive deiodination. We have successfully applied the postglycosylational-deiodination strategy in the synthesis of more than 30 mono-, di-, tri-, tetra- and pentadeoxysaccharides with excellent stereoselectivity and efficiency. This method has also been applied to the synthesis of a 2-deoxy-tetrasaccharide containing four ?-linkages.
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Spatio-temporal distribution of phenolamides and the genetics of natural variation of hydroxycinnamoyl spermidine in rice.
Mol Plant
PUBLISHED: 10-01-2014
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Phenolamides constitute a diverse class of secondary metabolites that are found ubiquitously in plants and have been implicated to play important role in a wide range of biological processes such as plant development and defense. However, spatio-temporal accumulation patterns of phenolamides in rice, one of the most important crops, are not available so far, and no gene responsible for the phenolamides biosynthesis has been identified in this species. In this report, we report here the comprehensive metabolic profiling and natural variation analysis of phenolamides in a collection of rice germplasm using an LC-MS-based targeted metabolomics method. Spatio-temporal controlled accumulations were observed for most phenolamides, together with their differential accumulations between the two major subspecies of rice. Further metabolic genome-wide association study (mGWAS) in rice leaf and the in vivo metabolic analysis of the transgenic plants identified Os12g27200 and Os12g27254 as two spermidine hydroxycinnamoyl transferases that might be underlying the natural variation of levels of spermidine conjugates in rice. Our work demonstrates 'gene-to-metabolite' analysis by mGWAS provides a useful tool for functional gene identification and omics-based crop genetic improvement.
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Vasoprotective effect of PDGF-CC mediated by HMOX1 rescues retinal degeneration.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 09-29-2014
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Blood vessel degeneration is critically involved in nearly all types of degenerative diseases. Therefore strategies to enhance blood vessel protection and survival are highly needed. In this study, using different animal models and cultured cells, we show that PDGF-CC is a potent vascular protective and survival factor. PDGF-CC deficiency by genetic deletion exacerbated blood vessel regression/degeneration in various animal models. Importantly, treatment with PDGF-CC protein not only increased the survival of retinal blood vessels in a model of oxygen-induced blood vessel regression but also markedly rescued retinal and blood vessel degeneration in a disease model of retinitis pigmentosa. Mechanistically, we revealed that heme oxygenase-1 (HMOX1) activity is critically required for the vascular protective/survival effect of PDGF-CC, because blockade of HMOX1 completely abolished the protective effect of PDGF-CC in vitro and in vivo. We further found that both PDGF receptors, PDGFR-? and PDGFR-?, are required for the vasoprotective effect of PDGF-CC. Thus our data show that PDGF-CC plays a pivotal role in maintaining blood vessel survival and may be of therapeutic value in treating various types of degenerative diseases.
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Two-Dimensional Correlation Spectroscopic Analysis on the Interaction between Humic Acids and TiO2 Nanoparticles.
Environ. Sci. Technol.
PUBLISHED: 09-26-2014
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The elucidation of the interaction between TiO2 nanoparticles (NPs) and natural organic matter (NOM) can help one to better understand the fates, features, and environmental impacts of NPs. In this work, two-dimensional (2D) Fourier transformation infrared (FTIR) correlation spectroscopy (CoS) assisted by the fluorescence excitation-emission matrix (EEM) method is used to explore the interaction mechanism of humic acid (HA) with TiO2 NPs at a molecular level. The results show that the C?O bonds (carboxylate, amide, quinone, or ketone) and C-O bonds (phenol, aliphatic C-OH, and polysaccharide) of HA play important roles in their interaction with TiO2 NPs. The adsorption process of HA onto the surface of TiO2 NPs is different from the bonding process of the two species in solution. The forms of the relevant groups of HA and their consequent reaction with TiO2 NPs are affected to a great extent by the solution pH and the surface charge of NPs. The 2D-FTIR-CoS method is found to be able to construct a comprehensive picture about the NOM-TiO2 NPs interaction process. This 2D-FTIR-CoS approach might also be used to probe other complicated interaction processes in natural and engineered environments.
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Ginsenoside 20(S)?Rg3 inhibits the Warburg effect through STAT3 pathways in ovarian cancer cells.
Int. J. Oncol.
PUBLISHED: 09-24-2014
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Cancer cells prefer to metabolize glucose through aerobic glycolysis, known as the Warburg effect. It plays a crucial role in proliferation and progression of cancer cells. However, the complete mechanism remains elusive. In recent studies, the signal transducer and activator of transcription 3 (STAT3) signaling has been discovered to have roles in cancer?associated changes in metabolism. In this study, we find that the ginsenoside 20(S)?Rg3, a pharmacologically active component of the traditional Chinese herb Panax ginseng, inhibits glycolysis in ovarian cancer cells by regulating hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). We also show that 20(S)?Rg3 regulates HK2 through downregulation of p?STAT3 (Tyr705). Furthermore, overexpression of STAT3 in ovarian cancer cells weakened the suppression of Warburg effect induced by 20(S)?Rg3. Importantly, 20(S)?Rg3 treatment represses HK2 expression in nude mouse xenograft models of ovarian cancer. Taken together, our results show that 20(S)?Rg3 inhibits the Warburg effect by targeting STAT3/HK2 pathway in ovarian cancer cells, highlighting the potentiality of 20(S)?Rg3 to be used as a therapeutic agent for ovarian cancer.
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Prevalence and Risk Factors of Dry Eye Disease Among a Hospital-Based Population in Southeast China.
Eye Contact Lens
PUBLISHED: 09-19-2014
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To investigate the prevalence of dry eye disease (DED) and distribution of associated risk factors among a hospital-based population.
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Limnoithona sinensis as refuge for bacteria: protection from UV radiation and chlorine disinfection in drinking water treatment.
Can. J. Microbiol.
PUBLISHED: 09-18-2014
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In this study, we tested the potential of Limnoithona sinensis to provide its attached bacteria refuge against disinfection. The experimental results indicated that in water devoid of zooplankton, both UV radiation and chlorine disinfection significantly decreased the viability of free-living bacteria. In the presence of L. sinensis, however, the attached bacteria could survive and rapidly recover from disinfection. This demonstrated that L. sinensis provided protection from external damage to various aquatic bacteria that were attached to its body. The surviving bacteria remained on L. sinensis after disinfection exposure, which enabled a rapid increase in the bacterial population followed by their subsequent release into the surrounding water. Compared with UV radiation, chlorine disinfection was more effective in terms of inactivating attached bacteria. Both UV radiation and chlorine disinfection had little effect in terms of preventing the spread of undesirable bacteria, due to the incomplete inactivation of the bacteria associated with L. sinensis.
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Predictors of poor sleep quality and excessive daytime sleepiness in peritoneal dialysis patients.
Ren Fail
PUBLISHED: 09-17-2014
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Abstract To explore the possible impact factors on daytime sleepiness among peritoneal patients from a single center in China. A cross-sectional study was conducted in 98 prevalent peritoneal dialysis (PD) patients using both the Pittsburgh Sleep Quality Index (PSQI) questionnaire of sleep quality and the Epworth Sleepiness Scale (ESS) questionnaire of excessive daytime sleepiness (EDS). Biochemical differences between daytime sleepiness and non-daytime sleepiness population were evaluated, following univariate and multivariable analysis to find the risk factors on sleep disturbance. The prevalence of "poor sleep quality" (PSQI?>?5) was 74.49%, while daytime sleepiness (ESS???9) occurred in 22.45%. Mean PSQI was 9.06?±?4.60 and EES was 6.31?±?4.98. Compared to non-EDS cases, patients with ESS???9 had worse residual renal function (RRF), higher serum creatinine, higher serum magnesium and elevated serum ferritin. In univariate analysis, ESS correlated with serum albumin (r?=?0.346, p?=?0.015), phosphate (r?=?0.313, p?=?0.029), magnesium (r?=?0.376, p?=?0.008) and urinary Kt/V (r?=?-0.341, p?=?0.029). Finally, multivariable linear regression indicated that urinary Kt/V, PSQI and magnesium were independent predictors of ESS score. EDS does exist in PD patients and is associated both with poor nighttime sleep quality and lower RRF. Hypermagnesemia may be a treatable risk factor to improve daytime tiredness.
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PseKNC-General: a cross-platform package for generating various modes of pseudo nucleotide compositions.
Bioinformatics
PUBLISHED: 09-16-2014
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The avalanche of genomic sequences generated in the post-genomic age requires efficient computational methods for rapidly and accurately identifying biological features from sequence information. Towards this goal, we developed a freely available and open-source package, called PseKNC-General (the general form of pseudo k-tuple nucleotide composition), that allows for fast and accurate computation of all the widely used nucleotide structural and physicochemical properties of both DNA and RNA sequences. PseKNC-General can generate several modes of pseudo nucleotide compositions, including conventional k-tuple nucleotide compositions, Moreau-Broto autocorrelation coefficient, Moran autocorrelation coefficient, Geary autocorrelation coefficient, Type I PseKNC and Type II PseKNC. In every mode, >100 physicochemical properties are available for choosing. Moreover, it is flexible enough to allow the users to calculate PseKNC with user-defined properties. The package can be run on Linux, Mac and Windows systems and also provides a graphical user interface. Availability and implementation: The package is freely available at: http://lin.uestc.edu.cn/server/pseknc.
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A spongy graphene based bimorph actuator with ultra-large displacement towards biomimetic application.
Nanoscale
PUBLISHED: 09-16-2014
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Bimorph actuators, consisting of two layers with asymmetric expansion and generating bending displacement, have been widely researched. Their actuation performances greatly rely on the difference of coefficients of thermal expansion (CTE) between the two material layers. Here, by introducing a spongy graphene (sG) paper with a large negative CTE as well as high electrical-to-thermal properties, an electromechanical sG/PDMS bimorph actuator is designed and fabricated, showing an ultra-large bending displacement output under low voltage stimulation (curvature of about 1.2 cm(-1) at 10 V for 3 s), a high displacement-to-length ratio (?0.79), and vibration motion at AC voltage (up to 10 Hz), which is much larger and faster than that of the other electromechanical bimorph actuators. Based on the sG/PDMS bimorph serving as the "finger", a mechanical gripper is constructed to realize the fast manipulation of the objects under 0.1 Hz square wave voltage stimulation (0-8 V). The designed bimorph actuator coupled with ultra-large bending displacement, low driven voltage, and the ease of fabrication may open up substantial possibilities for the utilization of electromechanical actuators in practical biomimetic device applications.
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Effects of volumetric load in an anaerobic sequencing batch biofilm treating industrial saline wastewater.
Environ Technol
PUBLISHED: 09-16-2014
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Mustard tuber wastewater is of high salinity ([Cl(-1)]?=?18?23?g?L(-1)), high organic content (chemical oxygen demand, COD?=?4000?±?100?L(-1)) and biodegradability (BOD5/COD???0.5). The anaerobic sequencing batch biofilm reactor (ASBBR) pre-treatment, an important step to meet national discharge standard, was applied to reduce much of the organics in mustard tuber wastewater. The experiment for the effect of the volumetric load on ASBBR treating mustard tuber wastewater was conducted at different hydraulic retention times (HRTs) and volumetric exchange ratios (?). The ASBBR operating at 50% biomass density, 30?°C, influent COD concentration of 4000?±?100?mg?L(-1) and pH value of 7.0?±?0.2, the effluent COD concentration increased from 0.22 to 4?kgCOD?m(-3)d(-1) when the volumetric load increased from 100 to 1520?mg?L(-1). The effluent COD concentration differed when adopted different HRT and ? under the same volumetric load. And given certain influent levels, a higher performance of ASBBR could be achieved at a lower value of HRT and ?. The optimal operational load could be determined by limiting the COD concentration under different discharge conditions, based on the results obtained in experiments.
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Prediction of protein structural classes based on feature selection technique.
Interdiscip Sci
PUBLISHED: 09-11-2014
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The prediction of protein structural classes is beneficial to understanding folding patterns, functions and interactions of proteins. In this study, we proposed a feature selection-based method to accurately predict protein structural classes. Three datasets with sequence identity lower than 25% were used to test the prediction performance of the method. Through jackknife cross-validation, we have verified that the overall accuracies of these three datasets are 92.1%, 89.7% and 84.0%, respectively. The proposed method is more efficient and accurate than other existing methods. The present study will offer an excellent alternative to other methods for predicting protein structural classes.
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[Prevalence and influencing factors of dyslipidemia among the elderly in Changsha: a community-based study].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 09-10-2014
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To study the prevalence and influencing factors of dyslipidemia in the elderly in Changsha.
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TiCl4 promoted formal [3 + 3] cycloaddition of cyclopropane 1,1-diesters with azides: synthesis of highly functionalized triazinines and azetidines.
Org. Lett.
PUBLISHED: 09-05-2014
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A TiCl4 promoted formal [3 + 3] cycloaddition of cyclopropane 1,1-diesters with azides has been developed for the synthesis of highly functionalized triazinines. Both stoichiometric and substoichiometric versions of this reaction were accomplished dependent on the choice of solvent. It is noteworthy that the corresponding products could be easily converted to biologically important azetidines by simple thermolysis.
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Mechanism of pretreatment using magnetic poly(glycidyl methacrylate) resin in an ultrafiltration membrane system used in algae-rich water treatment.
Environ Technol
PUBLISHED: 09-03-2014
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Ultrafiltration (UF) membrane fouling brought by algae-rich water controlling has been the research focus in recent years. The pretreatment of magnetic poly(glycidyl methacrylate) (m-PGMA) for sedimental tank effluent was investigated as well as its performance in combined UF processes. The optimal dose of m-PGMA was found to be 5?mL/L, which can bring a significant improvement to the removal efficiency of natural organic matter. With regards to membrane fouling, the use of m-PGMA also resulted in lowered irreversible and reversible membrane resistances in comparison with results obtained when operating without m-PGMA. In addition, four classic filtration models were introduced to analyse the fouling mechanisms. The proportion of standard blocking of pores has been weakened in the mechanism of membrane fouling when the pretreatment of m-PGMA exists. A very loose cake layer and relieved pore blockage were observed by scanning electron microscopy during m-PGMA/UF process.
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Transport of graphene oxide nanoparticles in saturated sandy soil.
Environ Sci Process Impacts
PUBLISHED: 09-02-2014
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We examined the transport properties of graphene oxide nanoparticles (GONPs) in saturated sandy soil, under different solution chemistry conditions and flow velocities. GONPs exhibited high mobility in soil, even at 50 mM NaCl. While at relatively high ionic strength GONPs were less mobile in soil than in quartz sand, the differences were not significant. At a concentration of 0.5 mM, Ca(2+) significantly inhibited the transport of GONPs in soil, but only slightly inhibited the transport in quartz sand. This was because by complexing with the surface O-functionalities of both GONPs and soil components, Ca(2+) could enhance the aggregation of GONPs and bridge GONPs and soil grains. Increasing pH from 4 to 9 only slightly enhanced the transport of GONPs in soil, probably because the mobility of GONPs was already high at low pH. The presence of 10 mg L(-1) Suwannee River humic acid significantly enhanced the transport of GONPs in quartz sand at 35 mM, but only had a small effect for the transport in soil. This was possibly linked to the much smaller grain sizes and much more heterogeneous nature of the soil. Flow velocity had marked effects on the transport in soil, but essentially no effects on the transport in quartz sand. A two-site transport model incorporating both the blocking-affected attachment process and straining effects can effectively model the transport of GONPs. The high mobility of GONPs may have important implications for their environmental fate and effects.
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Anti-neurotoxicity effects of oxoisoaporphine-lipoic acid hybrids.
Chem. Biol. Interact.
PUBLISHED: 09-01-2014
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Four oxoisoaporphine-lipoic acid hybrids were designed, synthesized, and investigated in this study. To develop the hybrids, the oxoisoaporphine fragment was used for its inhibition of cholinesterases and ?-amyloid (A?) aggregation, while the unit of lipoic acid was used for its radical-capturing and neuroprotective effects. The hybrids exhibited moderate inhibitory effects on the activity of acetylcholinesterase (AChE), with IC50 values in the micromolar range and low toxicity in SH-SY5Y cells. Moreover, the learning and memory abilities, climbing capability, and average life expectancy of the A?42 transgenic Drosophila were all significantly improved by the hybrids. They also enhanced the intracephalic antioxidant activity, the metabolism, and the activity cholinesterase in the flies. More strikingly, A?42 aggregation in the hybrids-treated Drosophila was attenuated with effective neuroprotection. Our results indicate the potential of using these oxoisoaporphine-lipoic acid hybrids in AD treatments.
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High-resolution mapping and characterization of qRgls2, a major quantitative trait locus involved in maize resistance to gray leaf spot.
BMC Plant Biol.
PUBLISHED: 08-31-2014
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Gray leaf spot (GLS) caused by Cercospora zeae-maydis (Czm) or Cercospora zeina (Cz) is a devastating maize disease and results in substantial yield reductions worldwide. GLS resistance is a quantitatively inherited trait. The development and cultivation of GLS-resistant maize hybrids are the most cost-effective and efficient ways to control this disease.
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WWP2: a multifunctional ubiquitin ligase gene.
Pathol. Oncol. Res.
PUBLISHED: 08-29-2014
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The ubiquitin-proteasome system plays an important role in various celluar processes. WWP2, a recently identified ubiquitin E3 ligase, has been proved a multifunctional gene by degradation a series of targets via ubiquitin-dependent proteasome system, including PETN, Smads, Oct4, EGR2, TIRF and so. Hereafter, we reviewed the recent research process about the function of WWP2.
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Prediction of CpG island methylation status by integrating DNA physicochemical properties.
Genomics
PUBLISHED: 08-27-2014
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As an inheritable epigenetic modification, DNA methylation plays important roles in many biological processes. The non-uniform distribution of DNA methylation across the genome implies that characterizing genome-wide DNA methylation patterns is necessary to better understand the regulatory mechanisms of DNA methylation. Although a series of experimental technologies have been proposed, they are cost-ineffective for DNA methylation status detection. As complements to experimental techniques, computational methods will facilitate the identification of DNA methylation status. In the present study, we proposed a Naïve Bayes model to predict CpG island methylation status. In this model, DNA sequences are formulated by "pseudo trinucleotide composition" into which three DNA physicochemical properties were incorporated. It was observed by the jack-knife test that the overall success rate achieved by the proposed model in predicting the DNA methylation status was 88.22%. This result indicates that the proposed model is a useful tool for DNA methylation status prediction.
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An UV-vis spectroelectrochemical approach for rapid detection of phenazines and exploration of their redox characteristics.
Biosens Bioelectron
PUBLISHED: 08-21-2014
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Phenazines are widely distributed in the environment and play an important role in various biological processes to facilitate microbial metabolism and electron transfer. In this work, an efficient and reliable spectroelectrochemical method is developed to quantitatively detect 1-hydroxyphenazine (1-OHPZ), a representative phenazine, and explore its redox characteristics. This approach is based on the sensitive absorption change of 1-OHPZ in response to its changes under redox state in rapid electrochemical reduction. The redox reaction of 1-OHPZ in aqueous solution is a proton-coupled electron transfer process, with a reversible one-step 2e(-)/2H(+) transfer reaction. This spectroelectrochemical approach exhibits good linear response covering two magnitudes to 1-OHPZ with a detection limit of 0.48µM, and is successfully applied to detect 1-OHPZ from a mixture of phenazines produced by Pseudomonas aeruginosa cultures. This method might also be applicable in exploring the abundance and redox processes of a wide range of other redox-active molecules in natural and engineered environments.
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Guanosine exerts neuroprotective effects by reversing mitochondrial dysfunction in a cellular model of Parkinson's disease.
Int. J. Mol. Med.
PUBLISHED: 08-19-2014
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The mitochondria are the most important cytoplasmic organelles in determining cell survival and death. Mitochondrial dysfunction leads to a wide range of disorders, including neurodegenerative diseases. The central events in the mitochondrial?dependent cell death pathway are the activation of the mitochodrial permeability transition pore (mPTP) and the disruption of mitochondrial membrane potential, which cause the release of apoptogenic molecules and finally lead to cell death. This is thought to be at least partly responsible for the loss of dopaminergic neurons in Parkinson's disease (PD); thus, the attenuation of mitochondrial dysfunction may contribute to alleviating the severity and progression of this disease. Guanosine is a pleiotropic molecule affecting multiple cellular processes, including cellular growth, differentiation and survival. Its protective effects on the central nervous system and and on several cell types by inhibiting apoptosis have been shown in a number of pathological conditions. This study aimed to analyze the ability of guanosine to protect neuronal PC12 cells from the toxicity induced by 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which mediates selective damage to dopaminergic neurons and causes irreversible Parkinson-like symptoms in humans and primates. Our results demonstrated that the apoptosis of PC12 cells induced by MPP+ was significantly prevented by pre-treatment for 3 h with guanosine. In addition, guanosine attenuated the MPP+-induced collapse of mitochondrial transmembrane potential and prevented the sebsequent activation of caspase-3, thereby protecting dopaminergic neurons against mitochondrial stress-induced damage.
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Evolution of a gastric carcinoma cell-specific DNA aptamer by live cell-SELEX.
Oncol. Rep.
PUBLISHED: 08-18-2014
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Aptamers have emerged as promising molecular probes for disease diagnosis and therapy. In the present study, the entire live cell-SELEX method was used to generate gastric cancer cell?specific aptamers. Human gastric carcinoma AGS cells were used as target cells for positive selections and human normal gastric epithelial GES-1 cells as the negative cells for counter selections. The selection procedure was monitored by gel electrophoresis and flow cytometric analysis. By successive in vitro evolutions and subsequent cloning and sequencing, a gastric carcinoma cell?specific DNA aptamer termed cy-apt 20 with minimal recognition to the controls was identified from the final enriched ssDNA pool. Flow cytometry binding assays revealed that cy-apt 20 had a >70% binding rate to AGS cells and <30% binding affinity to non-gastric cancer cells. Furthermore, the targeting recognition of AGS cells was established by using minimal doses of FITC-cy-apt 20 that continued for a long period of time. As visualized by fluorescence imaging, the majority of AGS cells were stained by FITC-cy-apt 20. The fluorescence intensity of AGS cells was ~6-fold over that of non-AGS cells. The present study demonstrated that the entire live cell-SELEX was simple, but effective in generating gastric cancer cell?specific aptamers, and that the aptamer cy-apt 20 has great potential to be used for the study and diagnosis of gastric cancer.
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Sleep Apnea and the Risk of Chronic Kidney Disease: A Nationwide Population-Based Cohort Study.
Sleep
PUBLISHED: 08-06-2014
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Sleep apnea (SA) is characterized by apnea during sleep and is associated with cardiovascular diseases and an increase in all-cause mortality. Chronic kidney disease (CKD) is a global health problem that has placed a substantial burden on healthcare resources. However, the relationship between SA and the incidence of CKD is not clear. This study aimed to determine whether SA is an independent risk factor for the development of CKD.
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Transoral robotic surgery for treatment of obstructive sleep apnea: Factors predicting surgical response.
Laryngoscope
PUBLISHED: 08-04-2014
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We reviewed our experience with the use of transoral robotic surgery (TORS) for base of tongue (BOT) reduction either alone or as part of multilevel strategy in the treatment of obstructive sleep apnea/hypopnea syndrome (OSAHS) in order to identify clinical characteristics that may be associated with surgical response.
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Oligoclonal CD8+ T Cells Play a Critical Role in the Development of Hypertension.
Hypertension
PUBLISHED: 08-04-2014
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Recent studies have emphasized a role of adaptive immunity, and particularly T cells, in the genesis of hypertension. We sought to determine the T-cell subtypes that contribute to hypertension and renal inflammation in angiotensin II-induced hypertension. Using T-cell receptor spectratyping to examine T-cell receptor usage, we demonstrated that CD8(+) cells, but not CD4(+) cells, in the kidney exhibited altered T-cell receptor transcript lengths in V?3, 8.1, and 17 families in response to angiotensin II-induced hypertension. Clonality was not observed in other organs. The hypertension caused by angiotensin II in CD4(-/-) and MHCII(-/-) mice was similar to that observed in wild-type mice, whereas CD8(-/-) mice and OT1xRAG-1(-/-) mice, which have only 1 T-cell receptor, exhibited a blunted hypertensive response to angiotensin II. Adoptive transfer of pan T cells and CD8(+) T cells but not CD4(+)/CD25(-) cells conferred hypertension to RAG-1(-/-) mice. In contrast, transfer of CD4(+)/CD25(+) cells to wild-type mice receiving angiotensin II decreased blood pressure. Mice treated with angiotensin II exhibited increased numbers of kidney CD4(+) and CD8(+) T cells. In response to a sodium/volume challenge, wild-type and CD4(-/-) mice infused with angiotensin II retained water and sodium, whereas CD8(-/-) mice did not. CD8(-/-) mice were also protected against angiotensin-induced endothelial dysfunction and vascular remodeling in the kidney. These data suggest that in the development of hypertension, an oligoclonal population of CD8(+) cells accumulates in the kidney and likely contributes to hypertension by contributing to sodium and volume retention and vascular rarefaction.
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DC isoketal-modified proteins activate T cells and promote hypertension.
J. Clin. Invest.
PUBLISHED: 08-04-2014
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Oxidative damage and inflammation are both implicated in the genesis of hypertension; however, the mechanisms by which these stimuli promote hypertension are not fully understood. Here, we have described a pathway in which hypertensive stimuli promote dendritic cell (DC) activation of T cells, ultimately leading to hypertension. Using multiple murine models of hypertension, we determined that proteins oxidatively modified by highly reactive ?-ketoaldehydes (isoketals) are formed in hypertension and accumulate in DCs. Isoketal accumulation was associated with DC production of IL-6, IL-1?, and IL-23 and an increase in costimulatory proteins CD80 and CD86. These activated DCs promoted T cell, particularly CD8+ T cell, proliferation; production of IFN-? and IL-17A; and hypertension. Moreover, isoketal scavengers prevented these hypertension-associated events. Plasma F2-isoprostanes, which are formed in concert with isoketals, were found to be elevated in humans with treated hypertension and were markedly elevated in patients with resistant hypertension. Isoketal-modified proteins were also markedly elevated in circulating monocytes and DCs from humans with hypertension. Our data reveal that hypertension activates DCs, in large part by promoting the formation of isoketals, and suggest that reducing isoketals has potential as a treatment strategy for this disease.
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Inhibition of protein phosphatase 2A sensitizes pancreatic cancer to chemotherapy by increasing drug perfusion via HIF-1?-VEGF mediated angiogenesis.
Cancer Lett.
PUBLISHED: 07-11-2014
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Pancreatic cancer is a malignant disease without efficient treatment. Improved treatments are urgently needed to enhance or replace chemotherapy. Here we used a small molecular compound LB-100 to assess the effect of pharmacological inhibition of protein phosphatase 2A (PP2A) in combination with doxorubicin on the proliferation of pancreatic cancer in cell lines and a xenograft model. LB-100 moderately reduced PP2A activity and the growth of the cell lines but did not show chemosensitization in vitro. In vivo, however, LB-100 synergistically enhanced the activity of doxorubicin. This effect was associated with increased microvessel density, blood perfusion, and doxorubicin concentrations within the xenografts. Mechanically, LB-100 induced expression of hypoxia-induced factor-1? (HIF-1?) and vascular endothelial growth factor (VEGF). In an umbilical vein endothelial cell monolayer model for measuring changes in vascular permeability, increased VEGF secretion following exposure to LB-100 and doxorubicin was accompanied by increased amounts of doxorubicin penetrating the endothelial barrier. In conclusion, PP2A inhibition by LB-100 enhanced the cytotoxicity of doxorubicin in vivo but not in vitro potentially via HIF-1?-VEGF mediated angiogenesis. Combining inhibition of PP2A with chemotherapeutic regimens may enhance their effectiveness against pancreatic cancer.
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Epidemiological characteristics and outcome in elderly patients sustaining non-simultaneous bilateral hip fracture: A systematic review and meta-analysis.
Geriatr Gerontol Int
PUBLISHED: 07-09-2014
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The present study aimed to quantitatively and comprehensively conclude the epidemiological characteristics and outcome in elderly patients with non-simultaneous bilateral hip fractures.
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Transcriptional repression by the BRG1-SWI/SNF complex affects the pluripotency of human embryonic stem cells.
Stem Cell Reports
PUBLISHED: 07-08-2014
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The SWI/SNF complex plays an important role in mouse embryonic stem cells (mESCs), but it remains to be determined whether this complex is required for the pluripotency of human ESCs (hESCs). Using RNAi, we demonstrated that depletion of BRG1, the catalytic subunit of the SWI/SNF complex, led to impaired self-renewing ability and dysregulated lineage specification of hESCs. A unique composition of the BRG1-SWI/SNF complex in hESCs was further defined by the presence of BRG1, BAF250A, BAF170, BAF155, BAF53A, and BAF47. Genome-wide expression analyses revealed that BRG1 participated in a broad range of biological processes in hESCs through pathways different from those in mESCs. In addition, chromatin immunoprecipitation sequencing (ChIP-seq) demonstrated that BRG1 played a repressive role in transcriptional regulation by modulating the acetylation levels of H3K27 at the enhancers of lineage-specific genes. Our data thus provide valuable insights into molecular mechanisms by which transcriptional repression affects the self-renewal and differentiation of hESCs.
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The CCL2/CCR2 axis enhances IL-6-induced epithelial-mesenchymal transition by cooperatively activating STAT3-Twist signaling.
Tumour Biol.
PUBLISHED: 07-03-2014
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The pattern of secreted factors in the tumor microenvironment has been shown to initiate tumor epithelial-mesenchymal transition (EMT); however, little is known about their interplay undergoing this phenotypic switch. In this study, we revealed obvious coactions of cytokine IL-6 and chemokine CCL2 during EMT induction. We found that IL-6 effectively induced EMT and promoted tumor cell invasion, which could be markedly enhanced by addition of CCL2 in a CCR2-dependent manner. IL-6 and CCL2 induced each other and cooperatively elicited STAT3 phosphorylation; conversely, STAT3 regulated the production of IL-6 and CCL2, thus constituting a positive feedback loop to maintain and amplify STAT3 signaling, consequently promoting additional EMT events. Furthermore, CCL2 greatly enhanced IL-6-induced EMT events mainly by upregulating the expression of Twist. Genetic or pharmacological inhibition of STAT3 disrupted STAT3-centered loop and markedly suppressed Twist expression as well as IL-6/CCL2-mediated EMT induction. Thus, our findings highlighted the synergy of the two secreted factors of tumor microenvironment, in regulating transformed properties of non-small cell lung cancer (NSCLC).
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L312, a novel PPAR? ligand with potent anti-diabetic activity by selective regulation.
Biochim. Biophys. Acta
PUBLISHED: 06-24-2014
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Selective PPAR? modulators (sPPAR?M) retains insulin sensitizing activity but with minimal side effects compared to traditional TZD agents, is thought as a promising strategy for development of safer insulin sensitizer.
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The A395T Mutation in ERG11 Gene Confers Fluconazole Resistance in Candida tropicalis Causing Candidemia.
Mycopathologia
PUBLISHED: 06-17-2014
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The mechanism of fluconazole resistance in Candida tropicalis is still unclear. Recently, we isolated a fluconazole-resistant strain of C. tropicalis from the blood specimen of a patient with candidemia in China. In vitro antifungal susceptibility of the isolate was determined by using CLSI M27-A3 and E-test methods. The sequence of ERG11 gene was then analyzed, and the three-dimensional model of Erg11p encoded by ERG11 gene was also investigated. The sequencing of ERG11 gene revealed the mutation of A395T in this fluconazole-resistant isolate of C. tropicalis, resulting in the Y132F substitution in Erg11p. Sequence alignment and three-dimensional model comparison of Erg11ps showed high similarity between fluconazole-susceptible isolates of C. tropicalis and Candida albicans. The comparison of the three-dimensional models of Erg11ps demonstrated that the position of the Y132F substitution in this isolate of C. tropicalis is identical to the isolate of C. albicans with fluconazole resistance resulting from Y132F substitution in Erg11p. Hence, we ascertain that the Y132F substitution of Erg11p caused by A395T mutation in ERG11 gene confers the fluconazole resistance in C. tropicalis.
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Docetaxel with or without zoledronic acid for castration-resistant prostate cancer.
Int Urol Nephrol
PUBLISHED: 06-17-2014
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The aim of this study was to evaluate the efficacy and safety of zoledronic acid (ZA) in the combination of docetaxel-based chemotherapy for castration-resistant prostate cancer with bone metastases.
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Rational design of translational pausing without altering the amino acid sequence dramatically promotes soluble protein expression: A strategic demonstration.
J. Biotechnol.
PUBLISHED: 06-16-2014
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The production of many pharmaceutical and industrial proteins in prokaryotic hosts is hindered by the insolubility of industrial expression products resulting from misfolding. Even with a correct primary sequence, an improper translation elongation rate in a heterologous expression system is an important cause of misfolding. In silico analysis revealed that most of the endogenous Escherichia coli genes display translational pausing sites that promote correct folding, and almost 1/5 genes have pausing sites at the 3'-termini of their coding sequence. Therefore, we established a novel strategy to efficiently promote the expression of soluble and active proteins without altering the amino acid sequence or expression conditions. This strategy uses the rational design of translational pausing based on structural information solely through synonymous substitutions, i.e. no change on the amino acids sequence. We demonstrated this strategy on a promising antiviral candidate, Cyanovirin-N (CVN), which could not be efficiently expressed in any previously reported system. By introducing silent mutations, we increased the soluble expression level in E. coli by 2000-fold without altering the CVN protein sequence, and the specific activity was slightly higher for the optimized CVN than for the wild-type variant. This strategy introduces new possibilities for the production of bioactive recombinant proteins.
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The use of chlorine dioxide for the inactivation of copepod zooplankton in drinking water treatment.
Environ Technol
PUBLISHED: 06-10-2014
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The presence of zooplankton in drinking water treatment system may cause a negative effect on the aesthetic value of drinking water and may also increase the threat to human health due to they being the carriers of bacteria. Very little research has been done on the effects of copepod inactivation and the mechanisms involved in this process. In a series of bench-scale experiments we used a response surface method to assess the sensitivity of copepod to inactivation when chlorine dioxide (ClO2) was used as a disinfectant. We also assessed the effects of the ClO2 dosage, exposure time, organic matter concentration and temperature. Results indicated that the inactivation rate improved with increasing dosage, exposure time and temperature, whereas it decreased with increasing organic matter concentration. Copepod inactivation was more sensitive to the ClO2 dose than that to the exposure time, while being maintained at the same Ct-value conditions. The activation energy at different temperatures revealed that the inactivation of copepods with ClO2 was temperature-dependent. The presence of organic matter resulted in a lower available dose as well as a shorter available exposure time, which resulted in a decrease in inactivation efficiency.
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Synthesis of {100} Facet Dominant Anatase TiO2 Nanobelts and the Origin of Facet-Dependent Photoreactivity.
Chemistry
PUBLISHED: 06-07-2014
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Sword-like anatase TiO2 nanobelts exposed with 78?% clean {100} facets were synthesized and the facet-dependent photoreactivity of anatase TiO2 was investigated. By quantitative comparison with the reference {001} facets, the {100} facets possessed about ten-times higher active sites density than that on {001} facets, resulting in higher photoreaction efficiency. After the active sites density normalization, the {100} and {001} facets exhibited distinct wavelength-dependent photocatalytic performance, attributed to the anisotropic electronic structures in TiO2 crystals.
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Androgen receptor splice variants contribute to prostate cancer aggressiveness through induction of EMT and expression of stem cell marker genes.
Prostate
PUBLISHED: 06-06-2014
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The mechanism(s) by which androgen receptor (AR) splice variants contribute to castration-resistant prostate cancer (CRPC) is still lacking.
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Combined immunodeficiency develops with age in Immunodeficiency-centromeric instability-facial anomalies syndrome 2 (ICF2).
Orphanet J Rare Dis
PUBLISHED: 05-29-2014
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The autosomal recessive immunodeficiency-centromeric instability-facial anomalies syndrome (ICF) is characterized by immunodeficiency, developmental delay, and facial anomalies. ICF2, caused by biallelic ZBTB24 gene mutations, is acknowledged primarily as an isolated B-cell defect. Here, we extend the phenotype spectrum by describing, in particular, for the first time the development of a combined immune defect throughout the disease course as well as putative autoimmune phenomena such as granulomatous hepatitis and nephritis. We also demonstrate impaired cell-proliferation and increased cell death of immune and non-immune cells as well as data suggesting a chromosome separation defect in addition to the known chromosome condensation defect.
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A wheat 1-FEH w3 variant underlies enzyme activity for stem WSC remobilization to grain under drought.
New Phytol.
PUBLISHED: 05-22-2014
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In wheat stems, the levels of fructan-dominated water-soluble carbohydrates (WSC) do not always correlate well with grain yield. Field drought experiments were carried out to further explain this lack of correlation. Wheat (Triticum aestivum) varieties, Westonia, Kauz and c. 20 genetically diverse double haploid (DH) lines derived from them were investigated. Substantial genotypic differences in fructan remobilization were found and the 1-FEH w3 gene was shown to be the major contributor in the stem fructan remobilization process based on enzyme activity and gene expression results. A single nucleotide polymorphism (SNP) was detected in an auxin response element in the 1-FEH w3 promoter region, therefore we speculated that the mutated Westonia allele might affect gene expression and enzyme activity levels. A cleaved amplified polymorphic (CAP) marker was generated from the SNP. The harvested results showed that the mutated Westonia 1-FEH w3 allele was associated with a higher thousand grain weight (TGW) under drought conditions in 2011 and 2012. These results indicated that higher gene expression of 1-FEH w3 and 1-FEH w3 mediated enzyme activities that favoured stem WSC remobilization to the grains. The CAP marker residing in the 1-FEH w3 promoter region may facilitate wheat breeding by selecting lines with high stem fructan remobilization capacity under terminal drought.
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Predictive factors for acute proximal junctional failure after adult deformity surgery with upper instrumented vertebrae in the thoracolumbar spine.
Evid Based Spine Care J
PUBLISHED: 05-15-2014
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Study Type?Retrospective cohort study. Introduction?Acute proximal junctional failure (APJF) was recently defined by the International Spine Study Group as: postoperative fracture of the upper instrumented vertebrae (UIV) or UIV?+?1; UIV implant failure; proximal junctional kyphosis (PJK) increase?>?15 degrees; or need for proximal extension of the fusion within 6 months of surgery.1 The incidence and revision rates of APJF have been reported to be higher when the UIV is located in the lower thoracolumbar (TL) spine mostly because of high incidence of UIV or UIV?+?1 fractures.2 Sagittal deformity overcorrection has been considered as a potential risk factor.34 Objective?The purpose of this study is to assess independent predictive factors and timing for revisions of APJF in adult deformity patients with UIV in the TL (T9-L2) spine. Methods?Retrospective review of 135 consecutive patients with minimum 2-year follow-up, treated at a single institution for adult spinal deformity, all with UIV in the TL spine (T9-L2). Fusions were divided into three cohorts based on the UIV location (T9-T10 vs. T11-T12 vs. L1-L2). Demographic data were reviewed and radiographic parameters were measured preoperatively, immediately postoperatively, at 6 months and at the final follow-up. Incidence and failure modes of APJF, as well as timing for APJF revision are reported. Risk factors for APJF were assessed with univariate and multivariate regression analysis models. Results?A total of 135 consecutive patients were reviewed, with mean follow-up 42 months (24-126). Mean age was 66 years (24-86). There were no differences in the preoperative radiographic parameters between patients in any of the three cohorts with APJF. The incidence of APJF was 38.5%, with a trend toward higher APJF in the T9-T10 group (p?=?0.07) (Table 1). When UIV was at T10, the incidence of APJF was 57.1%, significantly higher than the adjacent vertebrae, T9 and T11 (p?=?0.03 and p?=?0.01, respectively). The overall revision rate for APJF was 17%, most often for UIV fracture, while PJK?>?15 degrees alone had the highest 2 and 5 years survival (100%) (Fig. 1). Univariate analysis revealed preoperative sagittal vertical axis?>?5 cm, postoperative PJA?>?5 degrees and thoracic kyphosis?>?30 degrees, and instrumentation to the pelvis as risk factors for APJF (Table 2). Multivariate regression analysis confirmed postoperative PJA?>?5 degrees, and greater correction of lumbar lordosis (LL) as independent risk factors for APJF (Table 3). Conclusion?The incidence of APJF in adult deformity patients is high if the UIV is in the lower thoracic or lumbar spine, with a trend toward higher rates when the UIV is at T10. Fracture at the UIV lead to the highest revision rate, while PJK?>?15 degrees without fracture or hardware failure had the longest revision-free survival. Postoperative PJA?>?5 degrees and greater correction of LL are independent risk factors for APJF.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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