bluuebunny/crossref_metadata_2025_split huggingface dataset:
Free radical oxidative copolymerization of indene with vinyl acetate and isopropenyl acetate: Synthesis and characterization
Authors: De Priyadarsi , Sathyanarayana D. N. 
Published: October 2002

AbstractCopolyperoxides of different compositions of indene with vinyl acetate and isopropenyl acetate were synthesized by the free radical‐initiated oxidative copolymerization. The compositions of copolyperoxides obtained from 1H‐ and 13C‐NMR spectra have been used to determine the reactivity ratio of the monomers. The reactivity ratios reveal that the copolyperoxides contain a larger proportion of the indene units in random placement. The NMR studies further suggest irregularities in the copolyperoxide chain possibly due to the cleavage reactions of the propagating peroxide radical. The thermal analysis by differential scanning calorimetry (DSC) supports the alternating peroxide units in the copolymer chain. The activation energy for the thermal degradation suggests that the degradation is dependent on the dissociation of the peroxide (OO) bonds in the copolyperoxide chain. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86:639–646, 2002
Use of novel hydrogels based on modified cellulosics and methacrylamide for separation of metal ions from water systems
Authors: Chauhan Ghanshyam S. , Mahajan Swati 
Published: October 2002

AbstractInterpenetrating networks (IPNs) based on extracted cellulose and its derivatives such as hydroxypropyl cellulose (HPC), cyanoethylcellulose, hydroxyethylcellulose, hydrazinodeoxycellulose, cellulosephosphate with methacrylamide (MAAm), and N,N‐methylene bisacrylamide were synthesized at reaction conditions evaluated for optimum network yield as a function of irradiation dose, concentrations of monomer and crosslinker, and amount of water. These networks were used in sorption of Fe2+, Cu2+, and Cr6+ ions. The networks were further functionlized by means of partial hydrolysis with 0.5N NaOH and metal ion sorption studies were carried out. Appreciable amount of all the three ions was sorbed and partial functionalization of the hydrogels results in selectivity in ion sorption with enhanced affinity for Fe2+ ions and total rejection of Cr6+ ions. These results are of interest for the development of low‐cost technologies based on smart hydrogels. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 667–671, 2002
Photoreactivity of vinyl ether/oxirane‐based resin systems
Authors: Chappelow C. C. , Pinzino C. S. , Power M. D. , Holder A. J. , Morrill J. A. , Jeang L. , Eick J. D. 
Published: October 2002

AbstractWe evaluated the reactivity in homopolymerization and as comonomers in dioxirane/polyol visible‐light curable systems the following vinyl ethers (VEs): mono‐, di‐, and tri(ethylene glycol) divinyl ethers (EGDVE, DEGDVE, and TEGDVE, respectively); 1,6‐hexanediol divinyl ether (HDDVE); cyclohexanedimethanol divinyl ether (CHDMDVE); glycidyl vinyl ether (GVE); 4‐(1‐propenyloxymethyl)‐1,3‐dioxolan‐2‐one (POMDO); and 1,4‐butanediol vinyl ether (BDVE). The dioxirane/polyols (80/20) were Cyracure UVR 6105 or ERL 4206 dioxiranes with polytetrahydrofuran [PTHF; number‐average molecular weight (Mn) = 250]. Reactivities were evaluated by photodifferential scanning calorimetry with visible light. For VE homopolymerization, the relative reactivity ranking (based on exotherm peak maximum time) was TEGDVE > EGDVE > DEGDVE > HDDVE > CHDMDVE > BDVE > GVE ≫ POMDO. For VEs in UVR 6105/PTHF, the ranking was GVE > TEGDVE > CHDMDVE > BDVE > EGDVE ≫ DEGDVE = HDDVE = POMDO. In ERL 4206/PTHF, the ranking was: GVE > TEGDVE > BDVE > DEGDVE ≫ HDDVE > EDGDVE ≫ CHDMDVE = POMDO. The incorporation of an electron‐donating reaction promoter, ethyl‐4‐dimethylaminobenzoate, generally shortened induction times and exotherm peak maximum times and increased rate constants for homopolymerizations and ternary polymerizations. Experimentally determined polymerization reactivities were compared with previously reported semiempirical quantum mechanical calculations of activation energies and heats of reaction. The results of laboratory and computational studies for selected compounds were in general agreement. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 314–326, 2002
Polyphosphazene/low‐density polyethylene blends: Miscibility and flame‐retardance studies
Authors: Chen Donghua , Cui Yanjun , Wang Xinlin , Tang Xiaozhen 
Published: October 2002

AbstractThe effect of poly(dianilinephosphazene) (PDAP) on the processability, thermal behavior, crystallinity, morphology, mechanical properties, and flammability behavior of low‐density polyethylene (LDPE) was studied. Plasticorder traces of PDAP/LDPE blends implied good processability and miscibility. Thermogravimetric analysis showed that PDAP improved the thermal stability of LDPE. X‐ray diffraction results indicated that PDAP was a semicrystalline polymer, and the crystallinity of the blends decreased with increasing PDAP content. A new reflection at 2θ = 23.15° was found in wide‐angle X‐ray diffraction spectra of the blends, indicating that these two components interacted with one another. The scanning electron microscopy microstructures of the blends also supported these findings. Moreover, PDAP substantially enhanced the limited oxygen index and elongation at break of LDPE. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 709–714, 2002
Thermal analysis of high‐density polyethylene and low‐density polyethylene with enhanced biodegradability
Authors: Contat‐Rodrigo L. , Ribes‐Greus A. , Imrie C. T. 
Published: October 2002

AbstractThe thermal properties of high‐density polyethylene (HDPE) and low‐density polyethylene (LDPE) filled with different biodegradable additives (Mater‐Bi AF05H, Cornplast, and Bioefect 72000) were investigated with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The DSC traces of the additives indicated that they did not undergo any significant phase change or transition in the temperature region typically encountered by a commercial composting system. The TGA results showed that the presence of the additive led to a thermally less stable matrix and higher residue percentages. The products obtained during the thermodegradation of these degradable polyolefins were similar to those from pure polyethylenes. The LDPE blends were thermally less stable than the HDPE blends. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 764–772, 2002
Thermal aging of undoped polyaniline: Effect of chemical degradation on electrical properties
Authors: Kieffel Yannick , Travers Jean Pierre , Ermolieff Anne , Rouchon Denis 
Published: October 2002

AbstractAging experiments, with a special emphasis on the atmosphere effect, have been carried out on undoped polyaniline, in its half‐oxidized state, namely emeraldine base (EB). The polymer has been aged under vacuum and in air atmosphere. The chemical degradation has been analyzed by several complementary techniques such as viscosity measurements, FTIR, XPS, and UV‐Vis‐nIR spectroscopy. We show that emeraldine base exhibits two different degradation mechanisms. The first one is intrinsic to the polymer and occurs independently on aging conditions (vacuum or air). It consists of crosslinking via tertiary amine groups created from imine nitrogen via double‐bond breaking. The second mechanism is extrinsic and occurs concomitantly with the first one upon aging in air. It consists of oxygen incorporation in a form of carbonyl groups and chain scission. Both degradation pathways result in a decrease of the electrical conductivity of the polymer due to the lowering of the average conjugation length. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 395–404, 2002
Extrudate swell and texture of PS, LDPE, ABS, PVC melts and their blends in extrusion capillary flow using a magnetic die
Authors: Sombatsompop N. 
Published: October 2002

AbstractThe extrudate swell behavior and extrudate texture of various thermoplastic melts, namely, polystyrene (PS), low‐density polyethylene (LDPE), acrylonitrile‐butadiene styrene (ABS) copolymer, poly(vinyl chloride) (PVC), and their blends, were examined weith a magnetic die system in a constant‐shear‐rate capillary rheometer at a shear rate range 5–28 s−1 and a temperature range 170–230 °C. The extrudate swell results obtained from the magnetic die were then compared with those produced by a nonmagnetic die. The results showed that the extrudate swell increased with shear rate, but decreased with temperature. In a pure polymer system, up to 25% increase in the extrudate swell was observed with the application of the magnetic field to the PS melt, and the effect decreased in the order ABS > LDPE > PVC. The extrudate swell changes were associated with the changes in rheological properties of the melts. The extrudate textures of the ABS and PVC melts were improved by the magnetic field. In PS/LDPE or PS/ABS blend, it was found that the magnetic die resulted in higher values of the extrudate swell than the nonmagnetic die for all blends, the magnetic effect being less as the LDPE or ABS content was increased. For PS/LDPE system, the extrudate swell of the PS melt did not change much with addition of 20% LDPE, but slightly decreased at the LDPE loading of 40%. At higher LDPE loadings, the extrudate swell increased towards the value of the pure LDPE melt. For PS/ABS system, the extrudate swell ratio progressively decreased with increasing ABS content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 509–517, 2002
The value of contrast‐enhanced color doppler ultrasound in the detection of vascularization of finger joints in patients with rheumatoid arthritis
Authors: Klauser Andrea , Frauscher Ferdinand , Schirmer Michael , Halpern Ethan , Pallwein Leo , Herold Manfred , Helweg Gernot , ZurNedden Dieter 
Published: October 2002

AbstractObjectiveA prospective study was performed to assess the usefulness of contrast‐enhanced color Doppler ultrasound (CDUS) in the evaluation of intraarticular vascularization of finger joints in patients with rheumatoid arthritis (RA).MethodsWe investigated 198 finger joints in 46 patients with RA, and 80 finger joints in 10 healthy volunteers. Joints with varying levels of clinical activity of inflammation were classified as being active, moderately active, or inactive. CDUS was performed with a high‐frequency multi‐D linear array transducer. A microbubble‐based ultrasound (US) contrast agent (Levovist; Schering, Berlin, Germany) was intravenously infused. Doppler findings were rated on the basis of both unenhanced and contrast‐enhanced CDUS images.ResultsHealthy joints showed no intraarticular vascularization on either unenhanced or contrast‐enhanced CDUS. Unenhanced CDUS detected intraarticular vascularization in 7 (8%) of 83 inactive joints, in 31 (52%) of 60 moderately active joints, and in 32 (58%) of 55 active joints. Contrast‐enhanced CDUS detected intraarticular vascularization in 41 (49%) of 83 joints with inactive RA, in 59 (98%) of 60 joints with moderately active RA, and in all 55 joints with active RA. Detection of intraarticular vascularization was improved by administration of the microbubble‐based US contrast agent (P < 0.001). Contrast‐enhanced CDUS demonstrated differences in intraarticular vascularization between joints with inactive RA and those with active RA (P < 0.001), between joints with inactive RA and those with moderately active RA (P < 0.001), and between joints with moderately active RA and those with active RA (P < 0.001).ConclusionThe use of a microbubble‐based US contrast agent significantly improved the detection of intraarticular vascularization in the finger joints of patients with RA. This technique seems to be a useful adjunct in the assessment of disease activity.
Smoking and disease severity in rheumatoid arthritis: Association with polymorphism at the glutathione S‐transferase M1 locus
Authors: Mattey Derek L. , Hutchinson David , Dawes Peter T. , Nixon Nicola B. , Clarke Sheila , Fisher June , Brownfield Ann , Alldersea Julie , Fryer Anthony A. , Strange Richard C. 
Published: October 2002

AbstractObjectiveTo determine whether the relationship between smoking and disease severity in women with rheumatoid arthritis (RA) is associated with polymorphism at the glutathione S‐transferase (GST) M1 locus.MethodsGenotyping for GSTM1 was carried out using polymerase chain reaction methodology on 164 women with established RA. Smoking history was obtained on each patient. Radiographic damage was measured by the Larsen score, and functional outcome was assessed by the Health Assessment Questionnaire (HAQ). Data were analyzed by multiple regression analyses, with correction for age and disease duration.ResultsEver having smoked was associated with a worse radiographic and functional outcome than was never having smoked. Both past and current smoking were associated with increased disease severity. Stratification by GSTM1 status revealed that polymorphism at this locus affected the relationship between smoking and disease outcome measures. Patients who lacked the GSTM1 gene and had ever smoked had significantly higher Larsen and HAQ scores than did those who lacked the gene and had never smoked. Radiographic outcome in these patients was worse than that in patients who had the GSTM1 gene and who had smoked. The associations were not affected by correction for socioeconomic status. Rheumatoid factor (RF) production was found to be associated with smoking in only the GSTM1‐null patients.ConclusionOur data suggest that disease outcome in female RA patients with a history of smoking is significantly worse than in those who have never smoked. Smoking was associated with the most severe disease in patients who carried the GSTM1‐null polymorphism. This association may be due in part to a relationship between the GSTM1 polymorphism and RF production in smokers.
Impaired growth hormone secretion in fibromyalgia patients: Evidence for augmented hypothalamic somatostatin tone
Authors: Paiva Eduardo S. , Deodhar Atul , Jones Kim D. , Bennett Robert 
Published: October 2002

AbstractObjectiveTo determine whether female fibromyalgia (FM) patients exhibit a normal growth hormone (GH) response to an acute exercise stressor, and to assess the importance of somatostatin tone in the generation of this GH response.MethodsTwenty female FM patients were compared with 10 healthy female controls. All subjects exercised to volitional exhaustion on a treadmill. A standard metabolic cart was used to monitor pulse, blood pressure, electrocardiography, oxygen uptake, carbon dioxide output, anaerobic threshold, and maximal workload. Blood was drawn for GH and cortisol measurements 1 hour before exercise, immediately before exercise, immediately after exercise, and 1 hour after exercise. One month later, testing that was exactly similar was performed, except all subjects were given pyridostigmine bromide (Mestinon; 30 mg orally) 1 hour before exercise.ResultsCompared with controls, FM patients failed to exhibit a GH or cortisol response to acute exercise (P = 0.003). After administration of pyridostigmine, 1 hour before exercise, the GH levels of FM patients increased 8‐fold (P = 0.001), to a value comparable with that of controls. Pyridostigmine did not increase the cortisol response to exercise in FM patients. Pyridostigmine alone did not stimulate GH secretion in FM patients, nor did it improve exercise‐induced GH secretion in controls. FM patients with normal insulin‐like growth factor 1 (IGF‐1) levels had an impaired GH response to exercise.ConclusionThree new findings are reported: 1) FM patients have a reduced GH response to exercise, 2) pyridostigmine reverses this impaired response, and 3) defective GH secretion in FM can occur in patients with normal IGF‐1 levels. Because pyridostigmine is known to reduce somatostatin tone, it is surmised that the defective GH response to exercise in FM patients probably results from increased levels of somatostatin, a hypothalamic hormone that inhibits GH secretion.
Differential role of neutrophil Fcγ receptor IIIB (CD16) in phagocytosis, bacterial killing, and responses to immune complexes
Authors: Fossati Gianluca , Moots Robert J. , Bucknall Roger C. , Edwards Steven W. 
Published: October 2002

AbstractObjectiveTo determine the roles played by the neutrophil Fcγ receptor type II (FcγRII) (CD32) and FcγRIIIb (CD16) in phagocytosis, bacterial killing, and activation by immune complexes (ICs) and to test the hypothesis that inhibition of pathologic effector neutrophil function is possible without compromising host defense.MethodsReceptor function was probed by enzymic removal of FcγRIIIb from the cell surface and by use of Fab/F(ab‘)2 fragments of monoclonal antibodies to block receptor‐ligand binding. Cells were challenged with (a) serum‐opsonized Staphylococcus aureus, (b) serum‐ and IgG‐opsonized latex particles, and (c) synthetic soluble and insoluble ICs to mimic bacterial and inflammatory stimuli.ResultsPhosphatidylinositol‐phospholipase C treatment removed >97% of surface FcγRIIIb from neutrophils previously treated with tumor necrosis factor α to mobilize intracellular stores of receptor. This treatment profoundly inhibited activation of primed neutrophils by soluble ICs of the type found in diseased rheumatoid joints, but had no effect on phagocytosis and killing of serum‐opsonized S aureus.ConclusionFcγRIIIb plays a major role in the secretion of toxic products in response to ICs, but little or no role in the phagocytosis and killing of serum‐opsonized bacteria. The selective suppression of effector neutrophil function is therefore possible. FcγRIIIb, or its intracellular signaling pathway, is a potential therapeutic target in inflammatory diseases such as rheumatoid arthritis, because disruption of its function should decrease inflammatory tissue damage, but not jeopardize host protection against infection.
Anti‐La/SSB antibodies transported across the placenta bind apoptotic cells in fetal organs targeted in neonatal lupus
Authors: Tran Hai B. , Macardle Peter J. , Hiscock Jenny , Cavill Dana , Bradley John , Buyon Jill P. , Gordon Tom P. 
Published: October 2002

AbstractObjectiveTo determine whether La and/or Ro epitopes on apoptotic cells in fetal organs that are targeted in neonatal lupus syndrome (NLS) are accessible for binding by autoantibodies in vivo, we traced the fate of transplacental autoantibodies in a murine passive transfer model.MethodsPregnant mice at day 15 of gestation (E15) were injected intraperitoneally with human anti‐Ro/La–positive sera or control sera, and transplacental transfer of human autoantibodies was tested by enzyme‐linked immunosorbent assay with recombinant antigens. Multiple cryostat sections at the level of the heart of E17 fetuses were visualized simultaneously for human IgG binding and apoptosis (TUNEL) under confocal microscopy. Serial paraffin sections of E17 and E19 fetuses were examined for histologic evidence of inflammation.ResultsHuman IgG anti–52‐kd Ro, anti–60‐kd Ro, and anti‐La autoantibodies were transported efficiently into the fetal circulation. Human IgG–apoptotic cell complexes were detected in the heart (atrial trabeculae and atrioventricular node), skin, liver, and newly forming bone of fetuses from mothers injected with anti‐Ro/La sera but not control sera. The IgG binding was fetal‐specific and organ‐specific; transplacental autoantibodies did not bind to apoptotic cells in the fetal thymus, lung, brain, or gut. The complexes were not associated with an inflammatory reaction. Injection of mothers with affinity‐purified anti‐La autoantibodies (but not anti‐Ro/La Ig depleted of anti‐La) revealed an identical location of IgG binding to apoptotic cells in the fetuses.ConclusionThis is the first study to demonstrate that transplacental anti‐La autoantibodies bind specifically to apoptotic cells in selected fetal organs in vivo, similar to the organ involvement in NLS. We hypothesize that additional factors are required to promote proinflammatory clearance of IgG–apoptotic cell complexes and subsequent tissue damage.
Regional quantification of cartilage type II collagen and aggrecan messenger RNA in joints with early experimental osteoarthritis
Authors: Matyas John Robert , Huang Dingqiu , Chung May , Adams Mark E. 
Published: October 2002

AbstractObjectiveAccurate assessment of chondrocyte metabolism is a potentially valuable indicator of cartilage health in osteoarthritis (OA). This study was conducted to explore the anabolic metabolism of chondrocytes early in the natural history of an experimental canine model of OA.MethodsCompetitive reverse transcription–polymerase chain reaction was used to calculate the copy number of type II collagen and the messenger RNA (mRNA) levels of aggrecan core protein in articular cartilage samples obtained from different regions of the femorotibial joint 12 and 39 weeks after cruciate transection.ResultsGene expression of both type II collagen and aggrecan in cartilage samples obtained from experimental joints at both intervals after surgery was elevated significantly compared with that in samples from contralateral control joints. The number of mRNA copies per microgram of DNA of aggrecan exceeded that of type II collagen in control cartilage, but the copy number of type II collagen mRNA exceeded that of aggrecan in OA cartilage. Thus, the ratio of type II collagen–to‐aggrecan mRNA copy number (normalized to DNA) was shown to be characteristically altered in cartilage with experimental OA.ConclusionAccurate assessment of multiple gene products in small samples of cartilage taken from focal areas of a joint can be used diagnostically for monitoring chondrocyte metabolism and possibly for staging at least the early phases of this joint disease.
Knee cartilage of spinal cord–injured patients displays progressive thinning in the absence of normal joint loading and movement
Authors: Vanwanseele B. , Eckstein F. , Knecht H. , Stüssi E. , Spaepen A. 
Published: October 2002

AbstractObjectiveAlterations in the morphologic, biochemical, and mechanical properties of cartilage occur after unloading and immobilization in animals. However, the findings have been inconsistent and it is unclear whether such changes also take place in humans. This study tested the hypothesis that progressive thinning of knee joint cartilage is observed after spinal cord injury.MethodsIn this in vivo study, knee cartilage was assessed in patients with complete, traumatic spinal cord injury at 6 (n = 9), 12 (n = 11), and 24 months (n = 6) after injury. Morphologic parameters of the knee cartilage (mean and maximum thickness as well as surface area) were computed from magnetic resonance imaging (MRI) data, and results were compared with those in young, healthy volunteers (n = 9).ResultsAfter 6 months of injury, the mean articular‐cartilage thickness was significantly less in the patella and medial tibia (decrease of 10% and 16%, respectively; P < 0.05), but not in the lateral tibia (decrease of 10%), compared with the MRI findings in healthy volunteers. After 12 and 24 months of injury, the differences amounted to a reduction of 21% and 23%, respectively, in the patella, 24% and 25%, respectively, in the medial tibia, and 16% and 19%, respectively, in the lateral tibia. The changes were significant in all 3 surfaces of the spinal cord–injured joint cartilage (P < 0.05–0.01).ConclusionOur data show, for the first time, that progressive thinning (atrophy) of human cartilage occurs in the absence of normal joint loading and movement. This may have important implications for patient management, in particular for spinal cord–injured patients and patients who are immobilized after surgery.