bluuebunny/crossref_metadata_2025_split huggingface dataset:
Presence of peripheral arthritis and male sex predicting continuation of anti–tumor necrosis factor therapy in ankylosing spondylitis: An observational prospective cohort study from the South Swedish arthritis treatment group register
Authors: Kristensen L. E. , Karlsson J. A. , Englund M. , Petersson I. F. , Saxne T. , Geborek P. 
Published: May 2010

AbstractObjectiveTo examine clinical characteristics as possible predictors of long‐term treatment continuation with adalimumab, etanercept, and infliximab in ankylosing spondylitis (AS) patients who had never taken biologics treated in clinical practice.MethodsPatients in southern Sweden with active AS starting biologic therapy for the first time between October 1999 and December 2008 (n = 243, 75% men) were included in a structured clinical followup over 2 years. Patients with clinical spondylitis had not responded to at least 2 nonsteroidal antiinflammatory drugs, whereas patients who also had peripheral arthritis (n = 121) had additionally failed at least 1 conventional disease‐modifying antirheumatic drug (DMARD) treatment course. The mean ± SD age at inclusion was 43 ± 12 years, with a mean ± SD disease duration prior to treatment of 16 ± 12 years.ResultsThe 2‐year drug continuation rate was 74%. Male sex (hazard ratio [HR] of premature discontinuation 0.36 [95% confidence interval (95% CI) 0.19–0.68]) and the presence of peripheral arthritis (HR 0.49 [95% CI 0.27–0.88]) were found to be significant predictors of better drug survival. Furthermore, a trend was seen for more favorable drug continuation on treatment with etanercept as compared with infliximab (HR 0.50 [95% CI 0.25–1.04], P = 0.062), whereas no differences were found comparing the 3 anti–tumor necrosis factor agents in other ways. Higher baseline C‐reactive protein level (HR 0.99 [95% CI 0.97–1.00], P = 0.12) and concomitant treatment with nonbiologic DMARDs (HR 0.61 [95% CI 0.34–1.10], P = 0.10) also showed trends to entail better drug adherence.ConclusionAS patients in this study have an excellent 2‐year drug survival rate of 74%. Significant predictors for treatment continuation in this study were male sex and the presence of peripheral arthritis.
Paraoxonase gene mutations in amyotrophic lateral sclerosis
Authors: Ticozzi Nicola , LeClerc Ashley Lyn , Keagle Pamela J. , Glass Jonathan D. , Wills Anne‐Marie , van Blitterswijk Marka , Bosco Daryl A. , Rodriguez‐Leyva Ildefonso , Gellera Cinzia , Ratti Antonia , Taroni Franco , McKenna‐Yasek Diane , Sapp Peter C. , Silani Vincenzo , Furlong Clement E. , Brown Robert H. , Landers John E. 
Published: May 2010

AbstractThree clustered, homologous paraoxonase genes (PON1, PON2, and PON3) have roles in preventing lipid oxidation and detoxifying organophosphates. Recent reports describe a genetic association between the PON genes and sporadic amyotrophic lateral sclerosis (ALS). We now report that in genomic DNA from individuals with familial and sporadic ALS, we have identified at least 7 PON gene mutations that are predicted to alter PON function. ANN NEUROL 2010
Preparation and properties of α‐chitin‐whisker‐reinforced hyaluronan–gelatin nanocomposite scaffolds
Authors: Hariraksapitak Parintorn , Supaphol Pitt 
Published: May 2010

AbstractTissue scaffolds made of naturally derived polymers present poor mechanical properties, which may limit their actual utilization in certain areas where high strength is a key criterion. This study was aimed at developing tissue scaffolds from a 50 : 50 w/w blend of hyaluronan (HA) and gelatin (Gel) that contained different amounts of acid‐hydrolyzed α‐chitin whiskers (CWs) by a freeze‐drying method. The weight ratios of the CWs to the blend were 0–30%. These scaffolds were characterized for their physical, physicochemical, mechanical, and biological properties. Regardless of the CW content, the average pore size of the scaffolds ranged between 139 and 166 μm. The incorporation of 2% CWs in the HA–Gel scaffolds increased their tensile strength by about two times compared to those of the other groups of the scaffolds. Although the addition of 20–30% CWs in the scaffolds improved their thermal stability and resistance to biodegradation, the scaffolds with 10% CWs were the best for supporting the proliferation of cultured human osteosarcoma cells (SaOS‐2). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
The influence of crosslinking agents on the morphology and electro‐optical performances of PDLC films
Authors: Kashima Miki , Cao Hui , Meng Qingyong , Liu Huijing , Wang Ding , Li Fasheng , Yang Huai 
Published: May 2010

AbstractThe morphology of polymer‐dispersed liquid crystal (PDLC) has a major impact on its electro‐optic properties. The PDLC was prepared by photochemical polymerization from UV‐curable monomers/crosslinking agent/initiator/LC mixture. The influences of crosslinking agents on the PDLC system had been studied. The microstructures of the PDLC were strongly influenced by the insertion of polyethylene glycol (600) diacrylate (PEGDA 600) crosslinker, relatively long and flexible branch, and diethylene glycol diacrylate (DEGDA) crosslinker along the network bone. The relative weight ratio of crosslinking agents and polymerization temperature had a significant effect on the LC domain size, and which resulted in influencing the electro‐optic properties of PDLC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
High‐frequency dielectric characterization for liquid crystalline polyimide/SiO2 nanocomposites
Authors: Ho Czung‐Yu , Chang Che‐Chiang , Lee Jiunn‐Yih 
Published: May 2010

AbstractIn this study, we investigated the influence of frequency, film thickness, and SiO2 content on the dielectric constant (K) and loss tangent (tan δ) of liquid crystalline polyimide (LCPi) and liquid crystalline polyimide/SiO2 (LCPi/SiO2) nanocomposites in a high frequency environment. We tested the loss tangent of the LCPi and LCPi/SiO2 nanocomposites within the high frequency 1 MHz to 3 GHz range, and determined its value to be between 0.01 and 0.001. In addition, we found a formant for frequencies ranging from 0.5 GHz to 1 GHz. We also inferred from the dielectric loss graphs of films with different thicknesses that the formants of the loss tangent shifted toward higher frequencies with increasing thicknesses. When measuring the dielectric constant at high frequencies, we found that the dielectric constant decreased markedly with increased SiO2 contents. Using the dielectric constant of high‐frequency circuit board materials as the standard, the dielectric constant of the LCPi/SiO2 nanocomposites at the frequency range from 1 MHz to 3 GHz was found to be as high as 2.2–3.4, thereby confirming the viability of LCPi/SiO2 nanocomposites as candidate materials for high‐frequency circuit board. In addition, the volume resistivity (ρV) of the LCPi and LCPi/SiO2 nanocomposites also increased with increased SiO2 contents. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Studies on α to β phase transformations in mechanically deformed PVDF films
Authors: R. P. Vijayakumar , Khakhar Devang V. , Misra Ashok 
Published: May 2010

AbstractPVDF cast films were drawn at different temperatures to different draw ratios at constant draw rate to understand the mechanism of α to β phase transformation during mechanical deformation. WAXD and FTIR studies were carried out to determine the formation and content of β phase in the drawn films. Lower stretch temperatures gave higher fractions of β phase. The cast PVDF films were also drawn at suitable temperatures below the PVDF ambient melting point to the draw ratio of 6.4. The highest fraction of β phase obtained in these ultra drawn films was 0.98. SALS studies carried out for films at different stretch ratios show the change in spherulitic structure with the stretching parameters and give information for the understanding of phase transformation during stretching of PVDF films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of vinyl pivalate/vinyl acetate comonomer composition on the self‐assembled morphology of poly(vinyl alcohol) prepared by in situ fibrillation: Preparation of PVA with a spherical morphology
Authors: Chirowodza Helen , Zou Mingxuan , Sanderson Ronald D. 
Published: May 2010

AbstractThe photoinitiated copolymerization of vinyl pivalate (VPi) and vinyl acetate (VAc) was carried out in bulk. Varying monomer feed ratios of VPi/VAc (mol %/mol %) of 100/0, 90/10, 60/40, 50/50, and 30/70 were used. Polyvinyl alcohol (PVA) with s‐diad contents ranging from 61.8% to 55.7% was obtained. The morphology and thermal properties of the different PVA samples were investigated. PVA prepared from PVPi homopolymer resulted in PVA with a well‐aligned microfibrillar structure. With a decrease in the VPi content in the precursor polymer, the fibrous morphology was gradually lost, resulting in PVA with mixtures of fibrillar and spherical structures. When the PVPi content was 38.5 mol %, only spherical particles were observed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Electroconductive paper prepared by coating with blends of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonate) and organic solvents
Authors: Montibon Elson , Lestelius Magnus , Järnström Lars 
Published: May 2010

AbstractElectroconductive papers were produced by coating commercial base papers with blends of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonate) (PEDOT:PSS) and organic solvents. The bulk conductivities of the coated papers were measured using a four‐probe technique. One‐sided and two‐sided coating gave comparable conductivity levels. The presence of sorbitol and isopropanol in the PEDOT:PSS blends did not enhance the bulk conductivity of the coated paper, and with increasing concentrations of these solvents, the conductivity decreased due to dilution of the conducting component. Samples coated with PEDOT:PSS blends containing N‐methylpyrrolidone (NMP) or dimethyl sulfoxide (DMSO) exhibited a higher conductivity than those coated with pure PEDOT:PSS because of their plasticizing effect and conformational changes of PEDOT molecules indicated by the red shift and disappearance of the shoulder peak at about 1442 cm−1 in the Raman spectra of the coated samples. EDS imaging showed that PEDOT:PSS is distributed throughout the thickness direction of the paper. Contact angle measurements were made to monitor the hydrophilicity of the paper surface and total sulfur analysis was used to determine the amount of PEDOT:PSS deposited onto the paper. The tensile strength of all the paper samples increased slightly after treatment. Thus, it is demonstrated that enhanced bulk conductivity in the order of 10−3 S/cm can be achieved by using organic conductive materials and surface treatment techniques. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Grafting of polystyrene and poly(p‐chlorostyrene) from the surface of ramie fiber via RAFT polymerization
Authors: Yi Jie , Chen Jing , Liu Zhao‐Tie , Liu Zhong‐Wen 
Published: May 2010

AbstractReversible addition‐fragmentation chain transfer (RAFT) radical polymerization was used for controlled grafting of styrene and p‐chlorostyrene from the surface of ramie fiber. The hydroxyl groups in ramie fiber were first converted to thiocarbonylthio groups as the RAFT chain transfer agent then used to mediate the RAFT polymerization of styrene, and p‐chlorostyrene in tetrahydrofuran using azobis (isobutyronitrile) as initiator at 60°C. The grafted copolymers were analyzed by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetry, and contact angle measurements. The results confirmed that grafting occurred on the surface of the ramie fiber, substantially increasing the water contact angle from 75.31° to 147° for polystyrene grafted ramie fiber (cell‐PS) and 135° for poly(p‐chlorostyrene) (cell‐PSCl), and improving the hydrophobicity of the grafted fiber. The homopolymers formed in the polymerization were analyzed by size exclusion chromatography to estimate the molecular weights and polydispersity indices (PDIs) of chains grafted from the surface of the ramie fiber, as well as showed narrow chain length distributions with a PDI of 1.32–1.70. These materials possess potential applications in many advanced technologies. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Lidocaine release from polycaprolactone threads
Authors: Perale Giuseppe , Casalini Tommaso , Barri Valentina , Müller Michele , Maccagnan Simone , Masi Maurizio 
Published: May 2010

AbstractIn the field of resorbable devices, drug eluting sutures represent an applied research field on which the reliability of both production processes and mathematical prediction modeling were tested. Indeed, poly‐ε‐caprolactone pellets were compounded with lidocaine and then extruded to obtain highly loaded threads. The complete and rapid release demonstrated that the extrusion process does not alter the drug, which is confirmed to be embedded in an open porous matrix, being free to be solvated by uptaken water and to diffuse. Release profile and polymer degradation were simulated through a mathematical model based on conservation laws that allowed to assess release kinetic and to confirm the understanding of involved phenomena, as it fit experimental data. Reliability and robustness of chosen model allow to monitor the overall quality of manufacturing because any discrepancy between experimental and simulated data can be adopted to assess drug distribution uniformity within the device. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and humic acid fouling resistance of poly(vinylidene fluoride)–fabric composite membranes for membrane distillation
Authors: Huo Ruiting , Gu Zhenya , Zuo Kaijie , Zhao Guangming 
Published: May 2010

AbstractA novel, flat‐sheet poly(vinylidene fluoride) (PVDF)–fabric composite membrane used for membrane distillation (MD) was prepared by coating and a wet‐phase inversion process. This is a simple and suitable method for preparing large, flat‐sheet MD membranes with high strengths and better fouling resistance. The PVDF–fabric composite membrane was a double‐layer membrane, containing a PVDF porous membrane layer on the fabric support. The polyester filament woven fabric, which was used as support of the composite membrane, was finished with the water‐and‐oil repellent agent FK‐510 or chitosan before the coating process. The effects of fabric finishing on the preparation and characteristics of the composite membrane were studied. The fouling resistance of the prepared composite membrane was investigated by air‐gap membrane distillation, with a saturated humic acid solution containing NaCl as the feed. The experimental results indicate that the fabric, finished with 2 g/L FK‐510 or 5 g/L chitosan, was suitable for preparing the composite membrane. With the protection of the fabric support, the prepared composite membrane exhibited better humic acid fouling resistance as its fabric support surface was in contact with the feed solution in the MD process, especially when the fabric support was finished with chitosan. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preirradiation‐induced emulsion graft polymerization of glycidyl methacrylate onto poly(vinylidene fluoride) powder
Authors: Yu Ming , Zhang Bowu , Deng Bo , Yang Xuanxuan , Sheng Kanglong , Xie Leidong , Lu Xiaofeng , Li Jingye 
Published: May 2010

AbstractAn epoxy‐group‐containing monomer, glycidyl methacrylate (GMA), was grafted onto poly(vinylidene fluoride) powder via preirradiation‐induced emulsion graft polymerization. The existence of graft chains was proven by chemical structure characterization with Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy analysis. The degree of grafting was calculated by means of fluorine content analysis. A kinetic study indicated that, with the emulsion graft polymerization system, the GMA conversion rate was high, exceeding 80%. The variation in the molecular weight of the grafted polymer was measured by gel permeation chromatography, and its crystallinity was investigated with differential scanning calorimetry. The epoxy groups in graft chains were found to be suitable for further chemical modification. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Ligand‐Exchange Processes on Solvated Zinc Cations: Water Exchange on [Zn(H2O)4(L)]2+⋅2 H2O (L=Heterocyclic Ligand)
Authors: Alzoubi Basam M. , Puchta Ralph , van Eldik Rudi 
Published: May 2010

AbstractThe water‐exchange mechanisms of [Zn(H2O)4(L)]2+⋅2 H2O (L=imidazole, pyrazole, 1,2,4‐triazole, pyridine, 4‐cyanopyridine, 4‐aminopyridine, 2‐azaphosphole, 2‐azafuran, 2‐azathiophene, and 2‐azaselenophene) have been investigated by DFT calculations (RB3LYP/6‐311+G**). The results support limiting associative reaction pathways that involve the formation of six‐coordinate intermediates [Zn(H2O)5(L)]2+⋅H2O. The basicity of the coordinated heterocyclic ligands shows a good correlation with the activation barriers, structural parameters, and stability of the transition and intermediate states.
A Triazacyclononane‐Based Bifunctional Phosphinate Ligand for the Preparation of Multimeric 68Ga Tracers for Positron Emission Tomography
Authors: Notni Johannes , Hermann Petr , Havlíčková Jana , Kotek Jan , Kubíček Vojtěch , Plutnar Jan , Loktionova Natalia , Riss Patrick Johannes , Rösch Frank , Lukeš Ivan 
Published: May 2010

AbstractFor application in positron emission tomography (PET), PrP9, a N,N′,N′′‐trisubstituted triazacyclononane with methyl(2‐carboxyethyl)phosphinic acid pendant arms, was developed as 68Ga3+ complexing agent. The synthesis is short and inexpensive. GaIII and FeIII complexes of PrP9 were characterized by single‐crystal X‐ray diffraction. Stepwise protonation constants and thermodynamic stabilities of metal complexes were determined by potentiometry. The GaIII complex possesses a high thermodynamic stability (log K[GaL]=26.24) and a high degree of kinetic inertness. 68Ga labeling of PrP9 is possible at ambient temperature and in a wide pH range, also at pH values as low as 1. This means that for the first time, the neat eluate of a TiO2‐based 68Ge/68Ga generator (typically consisting of 0.1 M HCl) can be directly used for labeling purposes. The rate of 68Ga activity incorporation at pH 3.3 and 20 °C is higher than for the established chelators DOTA and NOTA. Tris‐amides of PrP9 with amino acid esters were synthesized to act as models for multimeric peptide conjugates. These conjugates exhibit radiolabeling properties similar to those of unsubstituted PrP9.
The “Borrowing Hydrogen Strategy” by Supported Ruthenium Hydroxide Catalysts: Synthetic Scope of Symmetrically and Unsymmetrically Substituted Amines
Authors: Yamaguchi Kazuya , He Jinling , Oishi Takamichi , Mizuno Noritaka 
Published: May 2010

AbstractThe N‐alkylation of ammonia (or its surrogates, such as urea, NH4HCO3, and (NH4)2CO3) and amines with alcohols, including primary and secondary alcohols, was efficiently promoted under anaerobic conditions by the easily prepared and inexpensive supported ruthenium hydroxide catalyst Ru(OH)x/TiO2. Various types of symmetrically and unsymmetrically substituted “tertiary” amines could be synthesized by the N‐alkylation of ammonia (or its surrogates) and amines with “primary” alcohols. On the other hand, the N‐alkylation of ammonia surrogates (i.e., urea and NH4HCO3) with “secondary” alcohols selectively produced the corresponding symmetrically substituted “secondary” amines, even in the presence of excess amounts of alcohols, which is likely due to the steric hindrance of the secondary alcohols and/or secondary amines produced. Under aerobic conditions, nitriles could be synthesized directly from alcohols and ammonia surrogates. The observed catalysis for the present N‐alkylation reactions was intrinsically heterogeneous, and the retrieved catalyst could be reused without any significant loss of catalytic performance. The present catalytic transformation would proceed through consecutive N‐alkylation reactions, in which alcohols act as alkylating reagents. On the basis of deuterium‐labeling experiments, the formation of the ruthenium dihydride species is suggested during the N‐alkylation reactions.
From Surface‐Inspired Oxovanadium Silsesquioxane Models to Active Catalysts for the Oxidation of Alcohols with O2—The Cinnamic Acid/Metavanadate System
Authors: Ohde Christian , Limberg Christian 
Published: May 2010

AbstractSilsesquioxane dioxovanadate(V) complexes were investigated with respect to their potential as a catalyst for the oxidative dehydrogenation of alcohols with O2 as an oxidant. The turnover frequencies determined were comparatively low, but during the oxidation of cinnamic alcohol an increase in activity was observed in the course of the process, which was inspected more closely. It turned out that during the oxidation of cinnamic alcohol, not only was the aldehyde formed but also cinnamic acid, which in turn reacts with the silsesquioxane complex employed to give NBu4[O2V(O2CC2H2Ph)2], which can also be obtained from NBu4VO3 and cinnamic acid and represents a far more active catalyst, not only for cinnamic alcohol but also for other activated alcohols and hydrocarbons. The rate‐determining step of the conversion corresponds to an hydrogen‐atom abstraction from the CH units, as shown by the determination of the kinetic isotope effect in case of 9‐hydroxyfluorene, and the reoxidation of the reduced catalyst proceeds via a peroxo intermediate, which is also capable of oxidizing one alcohol equivalent. Furthermore the influence of the organic residues at the carboxylate ligands on the catalyst performance was investigated, which showed that the activity increases with decreasing pKs value. Moreover, it was found that during the oxidation the catalyst slowly decomposes, but can be regenerated by addition of excessive carboxylic acid.
A Cyclopeptide‐Derived Molecular Cage for Sulfate Ions That Closes with a Click
Authors: Fiehn Thomas , Goddard Richard , Seidel Rüdiger W. , Kubik Stefan 
Published: May 2010

AbstractThe 2:1 sandwich‐type complexes formed between a cyclopeptide with alternating L‐proline and 6‐aminopicolinic acid subunits and inorganic anions can be stabilized by covalently linking a tris‐alkyne and a tris‐azide derivative of this peptide through copper‐catalyzed azide–alkyne cycloaddition. The resulting triply linked bis‐cyclopeptide can interact with anions such as sulfate ions in aqueous solution by including them into the cavity between the two cyclopeptide rings, where they can form hydrogen bonds to amide NH groups, distributed along the inner surface. The binding kinetics of this system differ significantly from those of a bis‐cyclopeptide that contains only one linker because the rate of guest exchange is considerably slower. Thermodynamically, the stability of the sulfate complex of the triply linked bis‐cyclopeptide approaches a log Ka value of 6 in H2O/CH3OH 1:1 (v/v) which is, however, only approximately one order of magnitude larger than affinity of the more flexible monolinked analogue. Titration calorimetry revealed that this behavior is mainly due to the change in the binding enthalpy from exothermic to endothermic upon increasing the number of linkers. Results from NMR spectroscopy and X‐ray crystallography indicate that the mono‐ and triply linked bis‐cyclopeptides adopt similar conformations in their complexes with sulfate ions, but the complex formation is enthalpically unfavorable for the cage. The substantial entropic contribution to sulfate complexation of this receptor more than compensates for this disadvantage, so that the overall sulfate affinity of both bis‐cyclopeptides ends up in the same range. These investigations provide important insight into the structure–property relationships of such receptors, thus leading the way to further structural improvement.