bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cofactors of mitochondrial enzymes attenuate copper‐induced death in vitro and in vivo
Authors: Sheline Christian T. , Choi Eric H. , Kim‐Han Jeong‐Sook , Dugan Laura L. , Choi Dennis W. 
Published: October 2002

AbstractCopper toxicity contributes to neuronal death in Wilson's disease and has been speculatively linked to the pathogenesis of Alzheimer's and prion diseases. We examined copper‐induced neuronal death with the goal of developing neuroprotective strategies. Copper catalyzed an increase in hydroxyl radical generation in solution, and the addition of 20μM copper for 22 hours to murine neocortical cell cultures induced a decrease in ATP levels and neuronal death without glial death. This selective neuronal death was associated with activation of caspase‐3 and was reduced by free radical scavengers and Z‐Val‐Ala‐Asp fluoromethylketone, consistent with free radical–mediated injury leading to apoptosis. Pyruvate dehydrogenase is especially vulnerable to inhibition by oxygen free radicals, and the upstream metabolites, pyruvate, phosphoenolpyruvate, and 2‐phosphoglycerate were elevated in cortical cells after toxic exposure to copper. One approach to protecting pyruvate dehydrogenase from oxidative attack might be to enhance binding to cofactors. Addition of thiamine, dihydrolipoic acid, or pyruvate reduced copper‐induced neuronal death. To test efficacy in vivo, we added 1% thiamine to the drinking water of Long Evans Cinnamon rats, an animal model of Wilson's disease. This thiamine therapy markedly extended life span from 6.0 ± 1.6 months to greater than 16 months.
Electrical and mechanical characteristics of composites consisting of fractionated poly(3‐hexylthiophene) and conducting particles
Authors: Miyauchi Shinnosuke , Kondo Takamitsu , Oshima Kenji , Yamauchi Takeshi , Shimomura Masato , Mitomo Hiroshi 
Published: October 2002

AbstractThe dynamic viscoelasticity of fractionated poly(3‐ hexylthiophene)titanium carbide (P3HT/TiC) composites was examined with regard to their electrical characteristics. The elastic modulus (E′) at 0°C [i.e., near the glass‐transition temperature (Tg) of P3HT] increased with increasing TiC content of the composite. In particular, composites whose TiC content exceeded the threshold concentration showed a high E′. This was caused by the high E′ of TiC and the strong interaction between TiC and P3HT. When the sample was heated above the Tg, E′ decreased rapidly and an increase in the loss tangent appeared near the Tg of P3HT. Mechanical loss was caused by friction between TiC and P3HT. The change in mechanical characteristics affected the electrical conductivity. When the TiC content of the composite approximated to the threshold concentration, a significant change in mechanical characteristics took place, so that a large positive temperature coefficient (PTC) effect was observed near the Tg. To explain the PTC phenomenon, we propose a model of conductive pathway for P3HT/TiC. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1429– 1433, 2002
Polyion complex composite membranes for the separation of methyl t‐butyl ether/methanol mixtures: Separation behaviors of these membranes
Authors: Kim Sang‐Gyun , Kim Yong‐Il , Lim Gyun‐Taek , Jegal Jonggeon , Lee Kew‐Ho 
Published: October 2002

AbstractFor the pervaporation separation of methyl t‐butyl ether (MTBE)/methanol mixtures, polyion complex (PIC) composite membranes, composed of sodium alginate (SA) and chitosan, were prepared by alternating electrostatic adsorption of SA and chitosan on polysulfone‐supporting membrane. The pervaporation experiments were carried out under various preparation and operating conditions. The results showed that the prepared membranes strongly exhibited a methanol permselectivity for the MTBE/methanol mixtures, and moreover, through certain of these membranes, only methanol was permeated. Also, by increasing the chitosan content in the reaction solution, the permeation rates and MTBE concentrations in the permeate decreased gradually because of an increase in the ionic complexation between SA and chitosan. Furthermore, raising the pervaporation temperature led to an increase in both the permeation rate and the separation factor. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1832–1842, 2002
Pervaporation separation of water–ethanol mixtures using metal‐ion‐exchanged poly(vinyl alcohol) (PVA)/sulfosuccinic acid (SSA) membranes
Authors: Rhim Ji‐Won , Lee Sun‐Wha , Kim Youn‐Kook 
Published: October 2002

AbstractPoly(vinyl alcohol)/sulfosuccinic acid (PVA/SSA) membranes in the hydrogen form were converted to monovalent metal ion forms Li+, Na+, and K+. The effect of exchange with metal ions was investigated by measuring the swelling of water–ethanol (10/90) mixtures at 30 °C and by the pervaporative dehydration performance test for aqueous ethanol solutions with various ethanol concentrations at 30, 40, and 50 °C. In addition, electron spectroscopy for chemical analysis (ESCA) analysis was carried out to study the quantity of metal ions in membranes. From the ESCA analysis, the lithium ion quantity in the resulting membranes is greater than that of any other metal ions in question because of the easy diffusion of a smaller metal ion into the membrane matrix. The swelling ratio was in the following order: PVA/SSA‐Li+ > PVA/SSA‐Na+ > PVA/SSA‐K+ membranes. For pervaporation, the PVA/SSA‐Na+ membrane showed the lowest flux and highest separation factor for all aqueous ethanol solutions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1867–1873, 2002
The use of polymers as sequestering agents for toxic metal ions
Authors: Eboatu A. N. , Diete‐Spiff S. T. , Ezenweke L. O. , Omalu F. 
Published: October 2002

AbstractPolymer‐metal complexes were formed by nonsolvent precipitation technique for the metals Co, Pb, Ni, Cr, and Fe, and polystyrene (Pst), Poly(vinyl chloride) (PVC), and Nylon 66. By means of Fourier transform Infrared studies, it was established that chemical bonds actually do exist between the metal ions and the polymers (i.e., that the metal ions are not simply adsorbed on the surface of the polymers). It was observed also that the degrees of metal‐polymer interaction vary from polymer, from metal ion to metal ion, and depend on the metal ion concentration. These observations are explained in terms of the atomic radii and charges on the transition metal ions. The number and type of interaction sites/ligands on the substrates are also considered relevant. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2781–2786, 2002
Preparation and properties of conductive polyaniline/poly‐ω‐aminoundecanoyle fibers
Authors: Zhang Qinghua , Wang Xianhong , Chen Dajun , Jing Xiabin 
Published: October 2002

AbstractHistorically, polyaniline (PANI) had been considered an intractable material, but it can be dissolved in some solvents. Therefore, it could be processed into films or fibers. A process of preparing a blend of conductive fibers of PANI/poly‐ω‐aminoundecanoyle (PA11) is described in this paper. PANI in the emeraldine base was blended with PA11 in concentrated sulfuric acid (c‐H2SO4) to form a spinning dope solution. This solution was used to spin conductive PANI / PA11 fibers by wet‐spinning technology. As‐spun fibers were obtained by spinning the dopes into coagulation bath water or diluted acid and drawn fibers were obtained by drawing the as‐spun fibers in warm drawing bath water. A scanning electron microscope was employed to study the effect of the acid concentration in the coagulation bath on the microstructure of as‐spun fibers. The results showed that the coagulating rate of as‐spun fibers was reduced and the size of pore shrank with an increase in the acid concentration in the coagulation bath. The weight fraction of PANI in the dope solution also had an influence on the microstructure of as‐spun fibers. The microstructure of as‐spun fibers had an influence on the drawing process and on the mechanical properties of the drawn fibers. Meanwhile, the electrically conductive property of the drawn fibers with different percentage of PANI was measured. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1458–1464, 2002
Solid‐state nuclear magnetic resonance study of polyurethane/natural fibers composites
Authors: Tavares Maria Inês B. , Mothé Cheila G. , Araújo Carla R. 
Published: October 2002

AbstractIn the present study, fiber‐reinforced plastics (FRP) were prepared with sisal and the sugarcane waste material. The composites of these fibers with polyurethanes were obtained by processing these materials in a Haake plastograph, and their homogeneity was characterized by nuclear magnetic resonance (NMR) measurements. The results are discussed in terms of composites interaction, homogeneity, and compatibility. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1465–1468, 2002
Acoustic properties of nitrile butadiene rubber for underwater applications
Authors: Jung Kyung‐Il , Yoon Suk Wang , Cho Kuk Young , Park Jung‐Ki 
Published: October 2002

AbstractAcoustic properties of nitrile butadiene rubber (NBR) specimens with carbon black as filler were investigated with different sulfur contents in the frequency range of 300‐1000 kHz. Their mechanical properties, such as density, hardness, tensile strength, were conventionally measured and correlated with their acoustic properties. Sound speeds in the specimens were increased with an increase in the sulfur content. The variation of sound speed was about 2–5% in the specimens, whereas the variation of density was less than 0.4%. Enhanced acoustic transmission was also observed with increasing sulfur content. It may be due to the hardness change from the increase of crosslinking density in the specimens. These results show that the mechanical properties of NBR can be nondestructively and accurately determined with the acoustic property measurements. By use of the desired mechanical and acoustic properties, the utilization of the NBR for underwater applications becomes less d
ficult. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2764–2771, 2002
Photosensitive barrier rib paste for plasma display panel and photolithographic process
Authors: Jeong Seung Won , Kim Woo Sik , Lee Dong Ho , Min Kyung Eun , Seo Kwan Ho , Kang Inn Kyu , Park Lee Soon 
Published: October 2002

AbstractBarrier ribs in color plasma display panels (PDPs) function to maintain the discharge space between two glass plates as well as to prevent optical crosstalk. Patterning of barrier ribs is one of the unique processes for making PDPs. In this work, photosensitive barrier rib pastes were prepared by incorporating binder polymer, solvent, functional monomers, photoinitiator, and barrier rib powder. Studies of the function of the materials for the barrier rib paste were undertaken. After optimization of the paste formulation and photolithographic process, the barrier rib could be obtained with good resolution up to 110–120 μm height and 80–90 μm width. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2092–2099, 2002
Pervaporation separation of water‐isopropyl alcohol mixtures with blend membranes of sodium alginate and poly(acrylamide)‐grafted guar gum
Authors: Toti Udaya S. , Aminabhavi Tejraj M. 
Published: October 2002

AbstractThe blend membranes of sodium alginate (Na‐Alg) and poly(acrylamide)‐grafted guar gum (PAAm‐g‐GG) in the ratios of 3:1 and 1:1 were prepared and studied for the pervaporation separation of water–isopropyl alcohol mixtures over the entire range of mixture composition at 30°C. Membranes prepared from neat Na‐Alg (M‐1) and the 1:1 blend of Na‐Alg and PAAm‐g‐GG (M‐3) showed the highest separation selectivity for 10 mass % water in the feed mixture, whereas membranes prepared with the 3:1 blend ratio of Na‐Alg to PAAm‐g‐GG showed the highest separation selectivity of 20 mass % water in the feed. Selectivity decreased with increasing amount of water in the feed for all the membranes, but these values show an increase with increasing amount of grafted copolymer in the blend mixture. Flux increased with increasing amount of water in the mixture, but the flux values did not change markedly with the PAAm‐g‐GG content in the blend membrane at the lower mass % water. At higher mass % of water, the flux values of the blends increase systematically with increasing amount of PAAm‐g‐GG in the blend polymer. For the 10 mass %‐containing binary mixtures, the pervaporation separation experiments were performed at 30, 40, and 50°C, and the resulting data were used to calculate the Arrhenius activation parameters. These data indicated activated pore‐type diffusion of the permeants in the membranes. Dynamic sorption studies were also performed on up to 40 mass % water–isopropyl alcohol mixtures at 30°C. These results, when analyzed by the empirical equation, indicated Fickian transport in all the cases. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2014–2024, 2002
Synthesis and characterization of nonionic 1‐vinyl‐2‐pyrrolidinone/methacryloxy silicone copolymers: Effects of molecular weight of silicone and crosslinking density
Authors: Kim Jin‐Chul , Song Myung‐Eon , Park Seung‐Kyu , Lee Eun‐Joo , Rang Moon‐Jeong , Ahn Ho‐Jeong 
Published: October 2002

AbstractNonionic 1‐vinyl‐2‐pyrrolidinone/methacryloxy silicone copolymers (VP/VS copolymers) were prepared and characterized as functions of molecular weight of silicone and crosslinking density. Fourier transform infrared spectroscopy, 13C‐NMR, and pyrolysis gas chromatography–mass spectrometry study showed that those copolymers were successfully synthesized. Also, the gel‐permeation chromatography spectrum exhibited a fairly narrow distribution of the molecular weight of the polymer. It was found that the turbidity in ethanol (EtOH) and the glass‐transition temperature of crosslinked VP/VS copolymers are influenced by the amount of crosslinking agent. However, in the case of branched VP/VS copolymers, a transparent solution was obtained, regardless of the molecular weight of silicone. SEM/EDS study revealed that silicone is more abundant on the coating surface than on the interface of coating/glass. This is probably because Si‐containing chains have lower surface energy than that of vinylpyrrolidinone‐containing chains. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2244–2253, 2002
Polypropylene/metallocene ethylene‐octene copolymer blends with a bimodal particle size distribution: Mechanical properties and their controlling factors
Authors: Premphet K. , Paecharoenchai W. 
Published: October 2002

AbstractBlends of polypropylene homopolymer (PP) and metallocene produced ethylene‐octene copolymer (EOR) with a bimodal particle size distribution were investigated. The aim of the work was to study the influences of EOR characteristics and its concentration on the tensile and impact properties of the blends. The matrix ligament thickness between rubber particles was measured and compared to those predicted using the theoretical models. The relationships between blend morphology and impact property were reported. It was found that the content of comonomer and molecular weight of the EOR as well as its concentration in the blends were the major factors controlling the tensile and impact properties of the blends. These factors became ineffective to impact property when the ligament thickness of the matrix was larger than the critical value (T ∼0.3–0.4 μm). To achieve blends of high impact strength, the ligament thickness between rubber particles should be smaller than the critical value, and for a certain ligament thickness, EOR with high octene content and high molecular weight was preferred. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2412–2418, 2002
Photopolymerization of N,N‐dimethylaminoethylmethacrylate studied by photocalorimetry
Authors: Pamedytytė V. , Abadie M. J. M. , Makuška R. 
Published: October 2002

AbstractPhotopolymerization of dimethylaminoethylmethacrylate (DMAEMA) is studied in bulk and in solutions in the presence of different photoinitiators using differential photocalorimetry (DPC). The rate of DMAEMA photopolymerization is slow compared to that of alkylmethacrylates. Bimodal DPC curves of DMAEMA photopolymerization in bulk are obtained. The type I photoinitiators (IRGACURE® 651 and IRGACURE® 1700), which produce free radicals by homolytic fragmentation of photoexcited molecules, are more effective in promoting photopolymerization of DMAEMA. The type II photoinitiators (benzophenone and IRGACURE® 500), which initiate DMAEMA photopolymerization through an H‐abstraction mechanism involving an amino group from the monomer (polymer), are less efficient and favor the formation of partly crosslinked products. The effects of the photoinitiator concentration, temperature, and solvent on the kinetic data are evaluated and discussed. A scheme of photopolymerization of DMAEMA, including the formation of intermediate DMAEMA based macromonomers, is proposed. The main point of the suggested scheme is a high chain transfer to the DMAEMA monomer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 579–588, 2002
Polymer distribution during bicomponent melt blowing of poly(propylene)/poly(ethylene terephthalate) and its improvement
Authors: Zhao Ron (Rongguo) , Wadsworth Larry C. , Zhang Dong , Sun Christine 
Published: October 2002

AbstractBicomponent melt blown (MB) microfiber nonwovens of poly(propylene) (PP) and poly(ethylene terephthalate) (PET) were produced in this study. It is interesting to analyze the polymer distribution uniformity across the web because it affects many end‐use properties. By utilizing the technique of differential scanning calorimetry (DSC), a standard working line between heat of fusion and weight percentage was constructed for mixtures of PP and PET components. The fitted equations were used for determination of a component percentage in a certain position across the MB web. Measurements were conducted from DSC re‐heating curves to achieve accurate results. The distribution of polymer varies with polymer mass ratio and processing conditions. The overall uniformity increased with the percentage of PP. When PP is the minor component in the polymer pair, it exhibits notably higher percentage in edge areas across the MB web. These results suggest the phase interface distortion of the polymer melt occurred at the entrance of the MB coat‐hanger die tip. The polymer distribution uniformity is improved by adjusting temperature profile of the MB die. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2885–2889, 2002
Whole‐genome linkage analysis of rheumatoid arthritis susceptibility loci in 252 affected sibling pairs in the United Kingdom
Authors: MacKay Kirsten , Eyre Stephen , Myerscough Anne , Milicic Anita , Barton Anne , Laval Steven , Barrett Jenny , Lee Dorothea , White Sarah , John Sally , Brown Matthew A. , Bell John , Silman Alan , Ollier William , Wordsworth Paul , Worthington Jane 
Published: October 2002

AbstractObjectiveTo undertake a systematic whole‐genome screen to identify regions exhibiting genetic linkage to rheumatoid arthritis (RA).MethodsTwo hundred fifty‐two RA‐affected sibling pairs from 182 UK families were genotyped using 365 highly informative microsatellite markers. Microsatellite genotyping was performed using fluorescent polymerase chain reaction primers and semiautomated DNA sequencing technology. Linkage analysis was undertaken using MAPMAKER/SIBS for single‐point and multipoint analysis.ResultsSignificant linkage (maximum logarithm of odds score 4.7 [P = 0.000003] at marker D6S276, 1 cM from HLA–DRB1) was identified around the major histocompatibility complex (MHC) region on chromosome 6. Suggestive linkage (P < 7.4 × 10−4) was identified on chromosome 6q by single‐ and multipoint analysis. Ten other sites of nominal linkage (P < 0.05) were identified on chromosomes 3p, 4q, 7p, 2 regions of 10q, 2 regions of 14q, 16p, 21q, and Xq by single‐point analysis and on 3 sites (1q, 14q, and 14q) by multipoint analysis.ConclusionLinkage to the MHC region was confirmed. Eleven non‐HLA regions demonstrated evidence of suggestive or nominal linkage, but none reached the genome‐wide threshold for significant linkage (P = 2.2 × 10−5). Results of previous genome screens have suggested that 6 of these regions may be involved in RA susceptibility.
Autoantibody to hLSm4 and the heptameric LSm complex in anti‐Sm sera
Authors: Eystathioy Theophany , Peebles Carol L. , Hamel John C. , Vaughn John H. , Chan Edward K. L. 
Published: October 2002

AbstractObjectiveTo characterize the 15‐kd human SmD‐like autoantigen and its associated proteins previously shown to be recognized by IgM antibodies in patients with Epstein‐Barr virus (EBV)‐induced infectious mononucleosis.MethodsThe full‐length complementary DNA for the 15‐kd protein was expressed as recombinant protein and analyzed for reactivity using biochemical analysis and immunoprecipitation (IP).ResultsThe 15‐kd protein was determined to be the human like‐Sm protein LSm4 (hLSm4). Rabbit antibody raised against the C‐terminal polypeptide immunoprecipitated a 68‐kd complex composed of LSm4 together with a group of smaller proteins ranging in size from 6.5 to 14 kd, consistent with the reported heptameric LSm complexes involved in U4/U6 duplex formation and messenger RNA (mRNA) decapping/degradation. About 80% of all anti‐Sm sera from patients with systemic lupus erythematosus (SLE) recognized the hLSm4 in vitro translated product, while 6.7% (29 of 434) immunoprecipitated from cell extracts hLSm4 together with the other members of the hLSm complex. Four sera (0.92%) showed apparently exclusive reactivity to the hLSm complex in the absence of reactivity to Sm core proteins in the IP assay.ConclusionThese findings document that while IgM, but not IgG, autoantibodies to LSm4 were found in sera from patients with EBV infection, IgG autoantibodies to hLSm4 are detected in a large number of anti‐Sm‐positive sera from patients with SLE. Importantly, in a small number of anti‐Sm sera the LSm complex can be recognized independently of the Sm core protein antigens. Our data introduce the concept that “Sm” autoantigens include Sm as well as LSm complexes involved in the maturation and degradation of mRNA.
Cost‐effectiveness analysis of the Lyme disease vaccine
Authors: Hsia Elizabeth C. , Chung James B. , Schwartz J. Sanford , Albert Daniel A. 
Published: October 2002

AbstractObjectiveA vaccine for Lyme disease was approved in 1998 for use in the US. Given the high cost of the vaccine, the low risk of Lyme disease in many areas, and the largely curable nature of the disease, the cost‐effectiveness of the vaccine in various risk groups is uncertain. This study was undertaken to examine the cost‐effectiveness of the Lyme disease vaccine and the factors that influence its cost‐effectiveness.MethodsWe constructed a Markov decision‐analysis model to evaluate the clinical effectiveness and cost‐effectiveness of the Lyme disease vaccine in populations at various levels of risk for the disease. The probabilities of clinical events and costs were estimated from reports in the literature. Sensitivity analyses assessed the impact of potential variations of parameters on model results.ResultsAt the average national incidence of Lyme disease (0.0067%), the incremental cost‐effectiveness of vaccination was ∼$1,600,000 per case averted when a yearly booster was given for 10 years after the standard initial vaccination regimen of 3 inoculations at 0, 1, and 12 months. For populations with an annual Lyme disease incidence of 1% (the incidence in several well‐defined geographical areas of the US), the incremental cost‐effectiveness was ∼$9,900 per case averted. Disease incidence had to exceed 10% before vaccination with yearly boosters became both more effective and more cost saving than no vaccination.ConclusionThe Lyme disease vaccine is cost‐effective only for individuals who live in areas where Lyme disease is endemic and who are frequently exposed to ticks.