bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic heterogeneity according to age at onset in bipolar disorder: A combined positional cloning and candidate gene approach
Authors: Dizier Marie‐Hélène , Etain Bruno , Lajnef Mohamed , Lathrop Mark , Grozeva Detelina , Craddock Nick , Henry Chantal , Gard Sébastien , Jamain Stéphane , Leboyer Marion , Bellivier Frank , Mathieu Flavie 
Published: May 2012

AbstractThis study is the first that formally tests for genetic heterogeneity of bipolar disorder (BD) according to age at onset (AAO) sub‐groups by combining positional cloning and candidate gene approaches. Our previous genome‐wide linkage‐scan identified five genomic regions linked to early‐onset form of BD. The present study uses association analysis to test genetic heterogeneity of candidate genes located in these five regions in a sample of 443 unrelated bipolar patients and 1,731 controls. The study involved the following steps: (1) test of heterogeneity by comparing early‐onset BD patients versus later‐onset BD patients; and (2) for significant results in step 1, comparison of early‐onset BD patients and later‐onset BD patients separately to controls. Two types of analyses were used: the single SNP test and the gene‐based association test. We provide evidence for genetic heterogeneity within the ADRB2 (beta‐2adrenoreceptor) gene region that is specifically associated with the early onset form of BD with an OR of 1.8. Unfortunately, the genotyping coverage of ADRB2 in the Wellcome Trust Case Control Consortium sample meant undermined our efforts to undertake a replication. However, as the ADRB2 gene product directly interacts with the CACNA1C gene product, and is known to be implicated in BD susceptibility, we conclude that further exploration of the relationships between ADRB2 and BD needs to be undertaken. © 2012 Wiley Periodicals, Inc.
Amidoxime copolymer beads containing Cu/Cu2O microparticles as a biocidal material for water disinfection
Authors: Gangadharan D. , Dixit Dhara , Popat Kiritkumar Mangaldas , Anand Pritpal Singh 
Published: May 2012

AbstractMacroporous crosslinked acrylonitrile‐divinylbenzene copolymer beads were synthesized by suspension polymerization technique. The beads were chemically modified to have amidoxime functional group, which was used as a solid support for anchoring copper microparticles. The copper ions loaded on the copolymer beads were reduced using strong reducing agent to have copper microparticles on the amidoxime copolymer beads. The size of copper particles formed depends upon the amount of copper ions loaded on the beads. The formation of copper microparticles on the copolymer was confirmed by instrumental analysis. The copper containing amidoxime copolymer beads were investigated for the biocidal activity. The size and the distribution of copper particles on the amidoxime copolymer beads influenced their biocidal activity. The biocidal activity was tested against two Gram‐positive bacteria, Bacillus subtilis and Staphylococcus aureus, and against two Gram‐negative bacteria, Pseudomonas aeruginosa and Escherichia coli. The beads containing copper particles showed better biocidal activity against the Gram‐negative bacteria when compared with the Gram‐positive organisms. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Gold deposition on Fe3O4/(co)Poly(N‐octadecyl methacrylate) hybrid particles to obtain nanocomposites With ternary intrinsic features
Authors: Yang Yuzhen , Mahdavian Ali Reza , Daniels Eric S. , Klein Andrew , El‐Aasser Mohamed S. 
Published: May 2012

AbstractHere, nanocomposite particles with three domains including magnetite nanoparticles, poly(N‐octadecyl methacrylate) (PODMA) or poly(N‐octadecyl methacrylate‐co‐1‐vinylimidazole) (P(ODMA‐co‐VIMZ)), and gold nanoparticles were prepared. Fe3O4 nanoparticles with narrow particle size distribution were prepared through a synthetic route in an organic phase in order to achieve good control of the size and size distribution and prevent their aggregation during their preparation. These magnetite nanoparticles, ∼ 5 nm in size, were then encapsulated and well‐dispersed in PODMA and P(ODMA‐co‐VIMZ) matrices via a miniemulsion polymerization process to obtain the corresponding nanocomposite particles. The results revealed that Fe3O4 nanoparticles were encapsulated and did not migrate towards the monomer/water interface during polymerization. The resulting latex was used as a precursor for the adsorption of Au3+ ions on the surface of the polymeric particles and subsequent reduction to produce Fe3O4/P(ODMA‐co‐VIMZ)/Au nanocomposite particles. The morphology of the particles from each step was fully characterized by TEM and AFM, and the results of DLS analysis showed their size and size distribution. Measurement of magnetic properties illustrated the superparamagnetic characteristic of the products and it was observed that the encapsulation process and deposition of gold had no effect on the magnetic properties of the resulting particles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis, properties and self‐assembly of intelligent core‐shell nanoparticles based on chitosan with different molecular weight and N‐isopropylacrylamide
Authors: Wang Yajing , Wang Jiu , Ge Liang , Liu Qi , Jiang Liqun , Zhu Jiabi , Zhou Jianping , Xiong Fei 
Published: May 2012

AbstractIn this study, a series of chitosan‐graft‐poly(N‐isopropylacrylamide) (CTS‐g‐PNIPAAm) copolymers based on different molecular weight (Mw) of CTS and NIPAAm were synthesized through the polymerization of NIPAAm in an acid aqueous solution. The structures were verified by Fourier transform infrared and nuclear magnetic resonance. The influence of the CTS Mw on the properties of the resulting copolymers and self‐assembled nanoparticles was fully examined. The grafting ratio and grafting efficiency of the copolymers increased with the CTS Mw. All the copolymers have a similar low critical solution temperature of 33.5°C, which was independent of the CTS Mw. Furthermore, the copolymers were less temperature sensitive, when CTS Mw increased to 200 kDa. Besides, once the CTS Mw increased to 700 kDa, the copolymers were less pH sensitive near the tumor site (from pH 7.4 to 6.8). The copolymers could form uniform nanoparticles once the temperature increased to 34°C, which was reversible. After crosslinking by N,N‐methylenebisacrylamide (MBA), structurally stable nanoparticles could be obtained. The results from Transmission electron microscope (TEM) and Atomic force microscopy (AFM) showed that the MBA crosslinked nanoparticles were uniformly spherical with a loose structure. Surface tension method indicated that the critical aggregate concentrations were 0.045, 0.042, 0.037, and 0.036 mg mL−1 prepared from CTS 50, 100, 200, and 700 kDa, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and characterization of in situ polymerized poly(methyl methacrylate)–cerium molybdate nanocomposite for electroanalytical application
Authors: Khan Asif Ali , Paquiza Leena 
Published: May 2012

AbstractIn the present study, a new technique to synthesize composites of poly(methyl methacrylate) cerium molybdate (PMMA–CeMoO4) is reported. The study concerns the characterization of poly(methyl methacrylate; PMMA) and PMMA–CeMoO4 nanocomposites are also discussed. The physical properties of the material were described using TGA–DTA, FTIR, X‐ray, TEM, and SEM studies. The adsorption efficiency towards heavy metal ions was determined by distribution studies and material was found to be highly selective for lead, a heavy toxic metal ion, indicating the utility of the synthesized material for the removal of this ion from the waste stream. The material was used as electroactive component for the construction of an ion‐selective membrane electrode. The membrane electrode was mechanically stable, having wide dynamic range, with quick response time and could be operated for at least 5 months without any considerable divergence in the potential response characteristics. The electrode was successfully used as indicator electrode in complexation titrations. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Analysis of the dielectric spectroscopy of an epoxy‐ZnO nanocomposite using the universal relaxation law
Authors: Yang Wenhu , Yi Ran , Hui Sisi , Xu Yang , Cao Xiaolong 
Published: May 2012

AbstractThere is currently no unified theory that explains the role of nanofillers in polymeric insulation. Consequently, different methods such as dielectric spectroscopy analysis are used to understand this role. The existence of a strong interaction between nanoparticles and a polymer is widely accepted. However, the interaction between dipoles has been taken into consideration in Jonscher's Universal Relaxation Law (URL) but not in the Debye theory. Hence, the URL was used in this article as a method to analyze the spectra of epoxy‐ZnO nanocomposites and to try to determine the nanoeffect mechanism. At 160°C above Tg (116°C), the typical phenomenon of low‐frequency dispersion occurs in the epoxy‐ZnO nanocomposites, and with filler loading increased up to 5 wt %, the value of n (calculated from the εr″ spectrum of the nanocomposites) increases both at high and low frequencies. This result indicates that higher loadings correspond to lower dielectric losses changing per radian. Moreover, the decrease in quasi‐direction conduction indicates that the gross dielectric losses of the nanocomposites are also less than pure epoxy resin (EP) at low frequencies. This finding may be attributed to the strong bonding between the nanofillers and the EP, which limits the movement of some macromolecular chains. The URL provides an analytical method for determining the mechanism of the effect of nanofillers on polymers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Thermal and flammability studies of poly(vinyl alcohol) composites filled with sodium hydroxide
Authors: Arora Sanjiv , Kumar Mahender , Kumar Mahesh 
Published: May 2012

AbstractPoly(vinyl alcohol) (PVA) is a polymer of great value due to its wide spread applications. The present article describes the effect of sodium hydroxide on the flammability, thermal degradation, and tensile strength properties of PVA. The PVA/sodium hydroxide composite films at different loading levels of sodium hydroxide, i.e., 0.5, 1, 2, 3, and 4.5 wt % were prepared by solution casting technique. Dynamic thermogravimetry was used to study the thermal degradation behavior of samples at four different linear heating rates, i.e., 2.5, 5, 10, and 20 °C min−1under nitrogen atmosphere. The degradation activation energy values were calculated using reliable and preferred multiple‐heating rate methods. Limiting oxygen index (LOI) and UL 94 tests were carried out to check the flammability behavior of the samples. The presence of sodium hydroxide in PVA brought significant changes in the thermal and flammability performance. PVA/sodium hydroxide samples though showed lower initial decomposition temperature, but overall more thermal stability results as evidenced from the higher activation energy and char residue values. LOI and UL 94 tests indicate that sodium hydroxide greatly enhanced the flame retardancy of PVA/sodium hydroxide films. Based on the thermal and flammability level, the optimum concentration of sodium hydroxide is worked out. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Ring opening metathesis copolymerization of norbornene with norbornadiene from solutions with different mole fractions of the comonomers catalyzed by Ru‐amine complexes
Authors: Silva Sá José L. , Nascimento Eduardo S. P. , Fonseca Larissa R. , Lima‐Neto Benedito S. 
Published: May 2012

AbstractCopolymers from norbornene (NBE) with norbornadiene (NBD) were synthesized via ring opening metathesis copolymerization varying the mole fractions of the comonomers (0.8 : 0.2; 0.6 : 0.4; 0.4 : 0.6; 0.2 : 0.8) for a total monomer quantity of 5000 equivalents/[Ru]. The batch reactions were performed with [RuCl2(PPh3)2(amine)] complex types as precatalysts, where amine is perhydroazepine (1) or piperidine (2), in CHCl3 (2 mL) in the presence of ethyl diazoacetate (5 μL) for different intervals of times (5, 30, 60, and 120 min) at 40°C. The copolymers were characterized by 13C NMR. Quantitative yields of isolated materials were obtained from solutions with NBD : NBE 0.8 : 0.2 mole fraction in the presence of 1, decreasing to 70% for NBD : NBE 0.2 : 0.8 solutions. Concerning 2, the yields were 70% at most. Polymeric materials obtained with 1 were less soluble in CHCl3 than those synthesized with 2. The dependence of the reaction yields and occurrence of crosslinking on the starting NBE : NBD proportion related to reactivity of the complexes 1 and 2 were discussed. A few differences in the amines such as ancillary ligands were sufficient to change the reactivity of the {RuCl2(PPh3)} moiety complex to provide copolymers with different compositions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Ultrastructural and Spectrophotometric Study on the Effects of Putative Triggers on Aortic Valve Interstitial Cells in In Vitro Models Simulating Metastatic Calcification
Authors: Bonetti Antonella , Mora Alberto Della , Contin Magali , Tubaro Franco , Marchini Maurizio , Ortolani Fulvia 
Published: May 2012

AbstractMetastatic calcification of cardiac valves is a common complication in patients affected by chronic renal failure. In this study, primary bovine aortic valve interstitial cells (AVICs) were subjected to pro‐calcific treatments consisting in cell stimulation with (i) elevated inorganic phosphate (Pi = 3 mM), to simulate hyperphosphatemic conditions; (ii) bacterial endotoxin lipopolysaccharide (LPS), simulating direct effects by microbial agents; and (iii) conditioned media (CM) derived from cultures of either LPS‐stimulated heterogenic macrophages (commercial murine RAW264.7 cells) or LPS‐stimulated fresh allogenic monocytes/macrophages (bCM), simulating consequent inflammatory responses, alone or combined. Compared to control cultures, spectrophotometric assays revealed shared treatment‐dependent higher values of both calcium amounts and alkaline phosphatase activity for cultures involving the presence of elevated Pi. Ultrastructurally, shared peculiar pro‐calcific degeneration patterns were exhibited by AVICs from these latter cultures irrespectively of the additional treatments. Disappearance of all cytomembranes and concurrent formation of material showing positivity to Cuprolinic Blue and co‐localizing with silver precipitation were followed by the outcropping of such a material, which transformed in layers outlining the dead cells. Subsequent budding of these layers resulted in the formation of bubbling bodies and concentrically laminated calcospherulae mirroring those in actual soft tissue calcification. In conclusion, the in vitro models employed appear to be reliable tools for simulating metastatic calcification and indicate that hyperphosphatemic‐like conditions could trigger valve calcification per se, with LPS and allogenic macrophage‐derived secretory products acting as possible calcific enhancers via inflammatory responses. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Albumin 3′untranslated region facilitates increased recombinant protein production from Chinese hamster ovary cells
Authors: Pearson Mark J. , Khazaipoul Siavash , Optun Asta , Pryme Ian F. , Stern Beate , Hesketh John E. 
Published: May 2012

AbstractChinese hamster ovary (CHO) cells are used for recombinant protein production in the pharmaceutical industry but there is a need to improve expression levels. In the present work experiments were carried out to test the effectiveness of different 3′untranslated regions (3′UTRs) in promoting production of a naturally secreted luciferase. Seamless cloning was used to produce expression vectors in which Gaussia princeps luciferase coding sequences were linked to the human albumin, immunoglobulin or chymotrypsinogen 3′UTR. Stably transfected CHO cells expressing these constructs were selected. Luciferase activity in the culture medium was increased 2–3‐fold by replacing the endogenous 3′UTR with the albumin 3′UTR and decreased by replacement with immunoglobulin or chymotrypsinogen 3′UTR. Replacement of the native 3′UTR with the albumin 3′UTR led to a 10‐fold increase in luciferase mRNA levels. Deletion analysis of the albumin 3′UTR showed that loss of nucleotides 1–50, which removed an AU‐rich complex stem loop region, caused significant reductions in both luciferase protein expression and luciferase mRNA levels. The results suggest that recombinant protein expression and yield could be improved by the careful selection of appropriate 3′UTR sequences.
A revisited folding reporter for quantitative assay of protein misfolding and aggregation in mammalian cells
Authors: Gregoire Simpson , Kwon Inchan 
Published: May 2012

AbstractProtein misfolding and aggregation play important roles in many physiological processes. These include pathological protein aggregation in neurodegenerative diseases and biopharmaceutical protein aggregation during production in mammalian cells. To develop a simple non‐invasive assay for protein misfolding and aggregation in mammalian cells, the folding reporter green fluorescent protein (GFP) system, originally developed for bacterial cells, was evaluated. As a folding reporter, GFP was fused to the C‐terminus of a panel of human copper/zinc superoxide dismutase (SOD1) mutants with varying misfolding/aggregation propensities. Flow cytometric analysis of transfected HEK293T and NSC‐34 cells revealed that the mean fluorescence intensities of the cells expressing GFP fusion of SOD1 variants exhibited an inverse correlation with the misfolding/aggregation propensities of the four SOD1 variants. Our results support the hypothesis that the extent of misfolding/aggregation of a target protein in mammalian cells can be quantitatively estimated by measuring the mean fluorescence intensity of the cells expressing GFP fusion. The assay method developed herein will facilitate the understanding of aggregation process of SOD1 variants and the identification of aggregation inhibitors. The method also has great promise for misfolding/aggregation studies of other proteins in mammalian cells.
Improving piezoelectric cell printing accuracy and reliability through neutral buoyancy of suspensions
Authors: Chahal Daljeet , Ahmadi Ali , Cheung Karen C. 
Published: May 2012

AbstractThe sedimentation and aggregation of cells within inkjet printing systems has been hypothesized to negatively impact printer performance. The purpose of this study was to investigate this influence through the use of neutral buoyancy. Ficoll PM400 was used to create neutrally buoyant MCF‐7 breast cancer cell suspensions, which were ejected using a piezoelectric drop‐on‐demand inkjet printing system. It was found that using a neutrally buoyant suspension greatly increased the reproducibility of consistent cell counts, and eliminated nozzle clogging. Moreover, the use of Ficoll PM400 was shown to not affect cellular viability. This is the first demonstration of such scale and accuracy achieved using a piezoelectric inkjet printing system for cellular dispensing. Biotechnol. Bioeng. 2012; 109: 2932–2940. © 2012 Wiley Periodicals, Inc.
Quantitative methods to characterize morphological properties of cell lines
Authors: Mancia Annalaura , Elliott John T. , Halter Michael , Bhadriraju Kiran , Tona Alessandro , Spurlin Tighe A. , Middlebrooks Bobby L. , Baatz John E. , Warr Gregory W. , Plant Anne L. 
Published: May 2012

AbstractDescriptive terms are often used to characterize cells in culture, but the use of nonquantitative and poorly defined terms can lead to ambiguities when comparing data from different laboratories. Although recently there has been a good deal of interest in unambiguous identification of cell lines via their genetic markers, it is also critical to have definitive, quantitative metrics to describe cell phenotypic characteristics. Quantitative metrics of cell phenotype will aid the comparison of data from experiments performed at different times and in different laboratories where influences such as the age of the population and differences in culture conditions or protocols can potentially affect cellular metabolic state and gene expression in the absence of changes in the genetic profile. Here, we present examples of robust methodologies for quantitatively assessing characteristics of cell morphology and cell–cell interactions, and of growth rates of cells within the population. We performed these analyses with endothelial cell lines derived from dolphin, bovine and human, and with a mouse fibroblast cell line. These metrics quantify some characteristics of these cells lines that clearly distinguish them from one another, and provide quantitative information on phenotypic changes in one of the cell lines over large number of passages. Published 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 1069–1078, 2012
Purification of IgG and albumin from human plasma by aqueous two phase system fractionation
Authors: Vargas Mariángela , Segura Álvaro , Herrera María , Villalta Mauren , Angulo Yamileth , Gutiérrez José María , León Guillermo , Burnouf Thierry 
Published: May 2012

AbstractThe current shortages in human plasma products at global levels justify the development of new, cost effective plasma fractionation methods. We have developed a fractionation process to obtain immunoglobulin G (IgG) and albumin‐enriched fractions based on polymer‐salt aqueous two phase system (ATPS). A small‐scale (0.02 L) ATPS composed of polyethyleneglycol 3350 (PEG), potassium phosphate and sodium chloride, at pH 6.1, was evaluated and subjected to 50‐fold scale‐up (1 L). Further purification of the fractions was performed using caprylic acid precipitation and ion exchange chromatography. Similar yield and purity were obtained at both small and large scales. IgG precipitated in the PEG rich upper phase at 83% recovery and 2.75‐fold purification factor. An 81% pure albumin fraction was obtained in the salt rich bottom phase with a 91% yield. After polishing, IgG was obtained at a recovery of 70% and a purity of 92%. Corresponding values for albumin were 91% and 90%. This IgG and albumin fractionation technology deserves further evaluation as it may represent a potential alternative to conventional plasma fractionation methods. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 1005–1011, 2012
Structural Characterization and Computer‐Aided Optimization of a Small‐Molecule Inhibitor of the Arp2/3 Complex, a Key Regulator of the Actin Cytoskeleton
Authors: Baggett Andrew W. , Cournia Zoe , Han Min Suk , Patargias George , Glass Adam C. , Liu Shih‐Yuan , Nolen Brad J. 
Published: May 2012

AbstractCK‐666 (1) is a recently discovered small‐molecule inhibitor of the actin‐related protein 2/3 (Arp2/3) complex, a key actin cytoskeleton regulator with roles in bacterial pathogenesis and cancer cell motility. Although 1 is commercially available, the crystal structure of Arp2/3 complex with 1 bound has not been reported, making its mechanism of action uncertain. Furthermore, its relatively low potency increases its potential for off‐target effects in vivo, complicating interpretation of its influence in cell biological studies and precluding its clinical use. Herein we report the crystal structure of 1 bound to Arp2/3 complex, which reveals that 1 binds between the Arp2 and Arp3 subunits to stabilize the inactive conformation of the complex. Based on the crystal structure, we used computational docking and free‐energy perturbation calculations of monosubstituted derivatives of 1 to guide optimization efforts. Biochemical assays of ten newly synthesized compounds led to the identification of compound 2, which exhibits a threefold increase in inhibitory activity in vitro relative to 1. In addition, our computational analyses unveiled a surface groove at the interface of the Arp2 and Arp3 subunits that can be exploited for additional structure‐based optimization.