bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mutations in potassium channel kcnd3 cause spinocerebellar ataxia type 19
Authors: Duarri Anna , Jezierska Justyna , Fokkens Michiel , Meijer Michel , Schelhaas Helenius J. , den Dunnen Wilfred F. A. , van Dijk Freerk , Verschuuren‐Bemelmans Corien , Hageman Gerard , van de Vlies Pieter , Küsters Benno , van de Warrenburg Bart P. , Kremer Berry , Wijmenga Cisca , Sinke Richard J. , Swertz Morris A. , Kampinga Harm H. , Boddeke Erik , Verbeek Dineke S. 
Published: July 2012

AbstractObjective:To identify the causative gene for the neurodegenerative disorder spinocerebellar ataxia type 19 (SCA19) located on chromosomal region 1p21‐q21.Methods:Exome sequencing was used to identify the causal mutation in a large SCA19 family. We then screened 230 ataxia families for mutations located in the same gene (KCND3, also known as Kv4.3) using high‐resolution melting. SCA19 brain autopsy material was evaluated, and in vitro experiments using ectopic expression of wild‐type and mutant Kv4.3 were used to study protein localization, stability, and channel activity by patch‐clamping.Results:We detected a T352P mutation in the third extracellular loop of the voltage‐gated potassium channel KCND3 that cosegregated with the disease phenotype in our original family. We identified 2 more novel missense mutations in the channel pore (M373I) and the S6 transmembrane domain (S390N) in 2 other ataxia families. T352P cerebellar autopsy material showed severe Purkinje cell degeneration, with abnormal intracellular accumulation and reduced protein levels of Kv4.3 in their soma. Ectopic expression of all mutant proteins in HeLa cells revealed retention in the endoplasmic reticulum and enhanced protein instability, in contrast to wild‐type Kv4.3 that was localized on the plasma membrane. The regulatory β subunit Kv channel interacting protein 2 was able to rescue the membrane localization and the stability of 2 of the 3 mutant Kv4.3 complexes. However, this either did not restore the channel function of the membrane‐located mutant Kv4.3 complexes or restored it only partially.Interpretation:KCND3 mutations cause SCA19 by impaired protein maturation and/or reduced channel function. ANN NEUROL 2012;72:870–880
Bayesian approach to electron correlation in density functional theory
Authors: Tsekov R. , Vayssilov G.N. 
Published: July 2012

AbstractIn the present communication we applied the Bayesian conditional probability approach to the wave function of a many‐electron system that resulted in the appearance of a quantum vector potential in the DFT Schrödinger equation due to electron correlation, apart from the correlation energy term. Mathematically, the effect of this vector potential is equivalent to a magnetic field that corresponds in particular to a conservative irrotational one if it is considered in connection with the correlation potential. An analysis of the effect of the correlation momentum on the electronic transitions suggested that the electron correlation increases the transition probability.
Preparation and characterization of TiO2 nanofibers via using polylactic acid as template
Authors: Liu Mengzhu , Cheng Zhiqiang , Yan Juntao , Qiang Linhui , Ru Xin , Liu Fei , Ding Dawei , Li Junfeng 
Published: July 2012

AbstractA simple procedure is reported for the fabrication of TiO2 nanofibers via electrospinning technique using polylactic acid (PLA), tetrabutyl titanate, and hexafluoroisopropanol as a spinning solution. TiO2 nanofibers (600–700 nm in diameter), with bundled nanofibrils align in the fiber direction, are obtained from the calcination of the as‐spun TiO2/PLA composite nanofibers at 550°C. The structure and physicochemical property of generated nanofibers are elucidated by Fourier transform‐Infrared radiation spectrometer, X‐ray diffraction, scanning electron microscope, and Thermogravimetric‐differential thermal analysis, respectively. The photocatalytical activity of the TiO2 nanofibers is testified by quantifying the degradation of methylene orange. The result indicates that the TiO2 nanofibers with pure anatase phase, which are prepared at 550°C, shows an excellent photocatalytic activity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Peering into polypyrrole–SDS nanodispersions: Rheological view
Authors: Gangopadhyay Rupali 
Published: July 2012

AbstractSynthesis and rheological properties of a series of polypyrrole (PPy) nanodispersions stabilized by sodium dodecyl sulfate (SDS) are described here. Changes in particle size, morphology, spectroscopy (UV–vis), and rheological properties (steady and dynamic) of the dispersions with variation in PPy fraction were studied. PPy nanoparticles (20–50 nm) incorporated within large micellar entanglements (>700 nm) were identified from transmission electron micrograph and dynamic light scattering studies. On standing the dispersions, electrostatic interaction among the micelles via Fe3+ comes into play and the dispersion is gradually crosslinked to form a soft gel. Shear thinning generally observed for steady rheology measurements (1–500 s−1) on freshly prepared dispersion is accounted for the breakdown of larger entanglements under high shear. The aged dispersion (before gelling), however, exhibits a viscosity plateau, characteristic of the crosslinked systems. The dispersion [with loss (G″) moduli > storage (G′) moduli] behaves like a viscous liquid and resembles to semidilute polymeric solutions. Zimm model is roughly followed by the system as revealed from the respective slopes of G′ and G″ curves. The partially crosslinked system (aged by 7 days) partly follows Maxwell model, and a crossover of G′ and G″ corresponding to a single relaxation time is obtained. Stability of the dispersion, nanoscopic particle size, moderate conductivity, and shear thinning behavior encourage its prospect as conducting ink/paint. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Essential work of fracture of low‐filled poly(methyl methacrylate)/starch composites
Authors: Ali S. Mohammad , Unnikrishnan G. , Joseph M. A. 
Published: July 2012

AbstractIn this study, poly(methyl methacrylate) (PMMA)/starch composites were prepared by a simple solvent casting method. The morphologies of the PMMA/starch composites were studied by scanning electron microscopy. The intermolecular interaction between PMMA and starch was investigated with Fourier transform infrared spectroscopy. The thermal properties of the PMMA/starch composites were compared with those of the pure PMMA sample. Thermogravimetric analysis showed that the thermal stability increased as the starch content increased in the composites. The biodegradability of the PMMA/starch composites was studied with a soil burial test. The degradability was measured in terms of mechanical strength, which increased as the starch content increased. The essential work of fracture (EWF) of the PMMA/starch composite films was investigated by the application of EWF theory under in‐plane (mode I) conditions, and we found that the toughness, in terms of the EWF of composites, increased compared to that of pure PMMA. The fracture of the composites was also evaluated by ANSYS software, and the results were compared to the experimental output. The increased toughness of these PMMA/starch composites may enable their application in the automobile and packaging industries. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis, characterization, and application of novel amphiphilic poly(D‐gluconamidoethyl methacrylate)‐b‐polyurethane‐b‐ poly(D‐gluconamidoethyl methacrylate) triblock copolymers
Authors: Vishwakarma Niraj Kumar , Mishra Avnish Kumar , Mishra Abhinay , Paira Tapas , Patel Vijay Kumar , Biswas Chandra Sekhar , Mandal Tarun Kumar , Maiti Pralay , Ray Biswajit 
Published: July 2012

AbstractNovel amphiphilic ABA‐type poly(D‐gluconamidoethyl methacrylate)‐b‐polyurethane‐b‐poly(D‐gluconamidoethyl methacrylate) (PGAMA‐b‐PU‐b‐PGAMA) tri‐block copolymers were successfully synthesized via the combination of the step‐growth and copper‐catalyzed atom transfer radical polymerization (ATRP). Dihydroxy polyurethane (HO‐PU‐OH) was synthesized by the step‐growth polymerization of hexamethylene diisocyanate with poly(tetramethylene glycol). PGAMA‐b‐PU‐b‐PGAMA block copolymers were synthesized via copper‐catalyzed ATRP of GAMA in N, N‐dimethyl formamide at 20°C in the presence of 2, 2′‐bipyridyl using Br‐PU‐Br as macroinitiator and characterized by 1H‐NMR spectroscopy and GPC. The resulting block copolymer forms spherical micelles in water as observed in TEM study, and also supported by 1H NMR spectroscopy and light scattering. Miceller size increases with increase in hydrophilic PGAMA chain length as revealed by DLS study. The critical micellar concentration values of the resulting block copolymers increased with the increase of the chain length of the PGAMA block. Thermal properties of these block copolymers were studied by thermo‐gravimetric analysis, and differential scanning calorimetric study. Spherical Ag‐nanoparticles were successfully synthesized using these block copolymers as stabilizer. The dimension of Ag nanoparticle was tailored by altering the chain length of the hydrophilic block of the copolymer. A mechanism has been proposed for the formation of stable and regulated Ag nanoparticle using various chain length of hydrophilic PGAMA block of the tri‐block copolymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Radiolytic introduction of multiple functional groups to multiwalled carbon nanotubes and their application as biosensor supports
Authors: Kim Kyo‐Il , Kim Beom‐Ju , Kim Ki‐Chul , Choi Seong‐Ho 
Published: July 2012

AbstractTyrosinase was immobilized on multiwalled carbon nanotube (MWNT) supports that were functionalized with multiple groups. It was then used for the detection of phenolic compounds. The radiation‐induced graft polymerization of 1‐[(4‐ethenylphenyl)methyl]‐3‐buthyl‐imidazolium chloride and vinyl ferrocene introduced functional groups derived from both species onto the nanotubes' surfaces: imidazolium salts that contained sites for the enzyme's immobilization via ionic bonding and ferrocene compounds that acted as electron transfer mediators via redox reactions. Using these additives at a 1 : 4 molar ratio resulted in an electrode with optimized current. The multifunctionalized nanotube supports were characterized by X‐ray photoelectron spectroscopy, transmission electron microscopy, and thermogravimetric analysis. The prepared tyrosinase‐immobilized biosensor showed a sensing range of 1.0 × 10−4
M to 7.0 × 10−4
M and was used for the detection of phenolic compounds in red wines. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Improving filtration performance of electrospun nanofiber mats by a bimodal method
Authors: Mei Yan , Wang Zhiming , Li Xinsong 
Published: July 2012

AbstractNanofiber filtration is drawing an ever‐increasing attention nowadays because of its high filtration efficiency as well as low basic weight. The objective of this study is to investigate the effect of structural characteristics on filtration performance with a single nanofiber mat between two pieces of nonwoven membranes. The filtration performance of nanofiber mats was evaluated by quality factor, the ratio of aerosol filtration efficiency to pressure drop. It was found that the quality factor dropped rapidly when the average fiber diameter (df) increased from 358 to 425 nm and decreased slowly from df = 425 nm to df = 1250 nm. This proved that gas‐slip effect occurred on nanofibers with smaller diameters. Similarly, the quality factor of unimodal nanofiber mat declined as the packing density increased. Meanwhile, these data were compared with corresponding prediction of ideal mats predominantly from theoretical equations. Nanofiber mats with bimodal fiber size distributions were tested at the same condition. When compared with the unimodal nanofiber mats having the same weight‐averaged fiber diameter and similar packing density, the bimodal nanofiber mats exhibited higher quality factors. Hence, the bimodal method is an effective method for the improvement of filtration performance. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Tunicamycin Inhibits PDGF‐BB‐Induced Proliferation and Migration of Vascular Smooth Muscle Cells Through Induction of HO‐1
Authors: Yi Nan , Chen Si‐yu , Ma Ai , Chen Peng‐sheng , Yao Bing , Liang Ting‐ming , Liu Chang 
Published: July 2012

AbstractThe abnormal proliferation and migration of vascular smooth muscle cell (VSMC), which is triggered by various external stimuli, contributes importantly to the pathogenesis of atherosclerosis and restenosis. Recent studies indicate that the endoplasmic reticulum (ER) stress is intensively involved in the pathophysiological changes of VSMCs by various stimuli. However, the direct effects of ER stress on VSMC proliferation and migration remain unknown. In this study, we found that pretreatment with tunicamycin (Tm), an ER stress inducer, significantly inhibited platelet‐derived growth factor (PDGF)‐BB‐induced VSMC proliferation and migration in a dose‐dependent manner without causing significant apoptosis. Tm stimulated the expression of the antioxidant gene heme oxygenase‐1 (HO‐1) both at the transcriptional and translational levels, while reducing phosphorylation and activation of mitogen‐activated protein (MAP) kinases. The negative regulative effects of Tm were associated with a decrease in cyclins and cyclin‐dependent kinases (CDKs) activation. More importantly, HO‐1 siRNA partially abolished the beneficial effects of Tm on VSMCs. These results indicate that Tm‐induced ER stress provides protection against the abnormal VSMC activation by PDGF‐BB, which may be mediated by the induction of HO‐1 and blockade of cell cycle reentry. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Association between maternal age and birth defects of unknown etiology ― United States, 1997–2007
Authors: Gill Simerpal K. , Broussard Cheryl , Devine Owen , Green Ridgely Fisk , Rasmussen Sonja A. , Reefhuis Jennita ,   and the National Birth Defects Prevention Study
Published: July 2012

AbstractBACKGROUND: Birth defects affect 3% of babies born, and are one of the leading causes of infant mortality. Both younger and older maternal age may pose increased risks for certain birth defects. This study assessed the relationship between maternal age at the estimated delivery date and the risk for birth defects. METHODS: Data were obtained from the National Birth Defects Prevention Study, a population‐based case‐control study including mothers across 10 states. Maternal age was stratified into six categories: <20, 20 to 24, 25 to 29, 30 to 34, 35 to 39, and ≥40 years, and also analyzed as a continuous variable. Logistic regression models adjusted formaternal race/ethnicity, education, body mass index (BMI), folic acid use, smoking, gravidity, and parental age difference were used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). RESULTS: For maternal age <20 years, associations with total anomalous pulmonary venous return (aOR, 2.3; 95% CI, 1.3–4.0), amniotic band sequence (aOR, 2.4; 95% CI, 1.5–3.8), and gastroschisis (aOR, 6.1; 95% CI, 4.8–8.0) were observed. For the ≥40 year age group, associations with several cardiac defects, esophageal atresia (aOR, 2.9; 95% CI, 1.7–4.9), hypospadias (aOR, 2.0; 95% CI, 1.4–3.0), and craniosynostosis (aOR, 1.6; 95% CI, 1.1–2.4) were observed. Results using maternal age as a continuous variable were consistent with those that used categorized maternal age. CONCLUSION: Elucidating risk factors specific to women ateither extreme of maternal age may offer prevention opportunities. All women should be made aware of prevention opportunities, such as folic acid supplementation, to reduce the occurrence of birth defects. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.
COX‐2 in the neurodegenerative process of Parkinson's disease
Authors: Teismann Peter 
Published: July 2012

AbstractThe enzyme cyclooxygenase‐2 (COX‐2), responsible for the first committed step in the synthesis of several important mediators which are involved in both initiation and resolution of inflammation, and the subsequent generation of prostaglandins (PGs) upon activation has been shown to participate in the neurodegenerative processes of a variety of diseases. This review looks particular at the role of COX‐2 in the pathogenesis of Parkinson's disease, involving the generation of PGs and the role of the two different parts of the cyclooxygenase—cyclooxygenase and peroxidase activity. © 2012 International Union of Biochemistry and Molecular Biology, Inc.
Arteriotomy closure device safety after percutaneous coronary intervention in the direct thrombin inhibitor era: A comparative study
Authors: Theodos Gus , Raymond Chad , Becker Matthew C. , Thornton Julie , Ellis Stephen G. , Bhatt Deepak L. , Raymond Russell E. 
Published: July 2012

ObjectivesTo investigate the safety and risk of vascular complications of arteriotomy closure devices (ACD) with the direct thrombin inhibitor bivalirudin in patients undergoing percutaneous coronary intervention (PCI).BackgroundACDs and manual compression have been shown to have a similar risk of complications in the setting of PCI with heparin ± glycoprotein (GP) IIb/IIIa inhibitor usage. In many centers bivalirudin is becoming the most frequent type of anticoagulation used during PCI. We sought to determine the risk of vascular complications using Angio‐Seal, Perclose, and manual compression for groin hemostasis using predominantly bivalirudin.MethodsOur institution's interventional database retrospectively identified 14,354 consecutive patients undergoing PCI from 2000 to 2008. Patients were grouped by the adjunctive anticoagulation used (bivalirudin vs. heparin + GP IIb/IIIa inhibitors) as well as ACD employed. The incidence of complications was evaluated using multivariable analysis to account for baseline differences between groups.ResultsPatients undergoing PCI with adjunctive bivalirudin had significantly fewer complications overall, regardless of closure method (2.9% vs. 8.7%, P < 0.001). The Perclose group had significantly fewer complications than the Angio‐Seal and manual compression groups (3.9% vs. 5.6% vs. 9.0%, P < 0.001) respectively; the Angio‐Seal group had significantly fewer complications than manual compression. Multivariable analysis also identified age ≥65, female gender, BMI ≤ 26, and operator as independent predictors of complications.ConclusionsThe use of adjunctive bivalirudin during PCI was associated with fewer vascular complications. In addition, the Perclose and Angio‐Seal devices had significantly fewer complications than manual compression and women ≥65 are at highest risk. © 2012 Wiley Periodicals, Inc.
DOTAM‐type ligands possessing arginine pendant groups for use in PARACEST MRI
Authors: Suchý Mojmír , Li Alex X. , Milne Mark , Bartha Robert , Hudson Robert H. E. 
Published: July 2012

ABSTRACTA synthetic methodology was developed for the preparation of metal‐chelating ligands that possess arginine pendant groups relying on the alkylation of 1,4,7,10‐tetraazacyclododecane (cyclen) with arginine‐containing electrophiles. Conditions for the selective trialkylation or peralkylation of cyclen are described, the outcome being dependent on the nature of the arginine‐derived electrophile and the solvent used for the reaction. Lanthanide metal complexes of the ligands prepared by the described route were evaluated for their suitability as PARACEST contrast agents for use in magnetic resonance imaging. The Dy3+ and Tm3+ complexes display CEST effects that are associated with the amide protons proximate to the metal center. These signals exhibit pH dependence in the range of 6.0–8.0 and thus may have the potential for pH measurement in physiological range. Copyright © 2012 John Wiley & Sons, Ltd.
Hyperpolarized 13C‐labelled anhydrides as DNP precursors of metabolic MRI agents
Authors: Colombo Serra Sonia , Karlsson Magnus , Giovenzana Giovanni Battista , Cavallotti Camilla , Tedoldi Fabio , Aime Silvio 
Published: July 2012

ABSTRACTThe extraordinary enhancement of the nuclear magnetic resonance (NMR) signal that can be obtained by dynamic nuclear polarization (DNP) techniques is prompting new avenues of research based on the in vivo detection of metabolic abnormalities associated with the onset and progression of human diseases. 13C‐labelled short‐chain fatty acids appear to be interesting candidates for this novel class of metabolic‐active contrast agents (MCAs), as they have been shown to report on metabolic differences between healthy and ischaemic tissues in mice. In spite of their promising biological efficacy, the formulations of short‐chain fatty acids that fulfil the many technical constraints of the DNP procedure, as it is today, may limit their clinical potential. New solutions have been sought to circumvent technology‐related challenges and facilitate clinical translation of these molecules. In particular, it has been shown that, by using symmetric anhydrides as chemical precursors for short‐chain fatty acids, no glass‐forming additives are needed in the DNP formulations. Furthermore, novel esterified trityl radicals and lipophilic gadolinium complexes allow easy removal of the polarization‐promoting additives at the end of the DNP process. By applying the three concepts reported, we have succeeded in preparing aqueous formulations of short‐chain fatty acids for pharmaceutical use that have favourable properties compared with those obtained from current procedures. The use of organic derivatives as chemical precursors of the MCA of interest appears to be a generally valid concept, not restricted to symmetric anhydrides of fatty acids, which can markedly improve the clinical potential of other 13C‐labelled compounds. Copyright © 2012 John Wiley & Sons, Ltd.
Nonuniform distribution of contacts from noradrenergic and serotonergic boutons on the dendrites of cat splenius motoneurons
Authors: Montague Steven J. , Fenrich Keith K. , Mayer‐Macaulay Colin , Maratta Robert , Neuber‐Hess Monica S. , Rose P. Ken 
Published: July 2012

AbstractThe input‐output properties of motoneurons are dynamically regulated. This regulation depends, in part, on the relative location of excitatory and inhibitory synapses, voltage‐dependent and ‐independent channels, and neuromodulatory synapses on the dendritic tree. The goal of the present study was to quantify the number and distribution of synapses from two powerful neuromodulatory systems that originate from noradrenergic (NA) and serotonergic (5‐HT) neurons. Here we show that the dendritic trees of motoneurons innervating a dorsal neck extensor muscle, splenius, in the adult cat are densely, but not uniformly innervated by both NA and 5‐HT boutons. Identified splenius motoneurons were intracellularly stained with Neurobiotin. Using 3D reconstruction techniques we mapped the distributions of contacts formed by NA and 5‐HT boutons on the reconstructed dendritic trees of these motoneurons. Splenius motoneurons received an average of 1,230 NA contacts (range = 647–1,507) and 1,582 5‐HT contacts (range = 1,234–2,143). The densities of these contacts were 10 (NA) to 6 (5‐HT)‐fold higher on small compared to large‐diameter dendrites. This relationship largely accounts for the bias of NA and 5‐HT contacts on distal dendrites and is partially responsible for the higher density of NA contacts on dendrites located more than 200 μm dorsal to the soma. These results suggest that the neuromodulatory actions of NA and 5‐HT are compartmentalized and regulate the input‐output properties of motoneurons according to precisely arranged interactions with voltage‐dependent and ‐independent channels that are primarily located on small‐diameter dendrites. J. Comp. Neurol. 521:638–656, 2013. © 2012 Wiley Periodicals, Inc.