bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of a polyacrylamidoxime chelating fiber and its efficiency in the retention of palladium ions
Authors: Bilba Nicolae , Bilba Doina , Moroi Gabriela 
Published: April 2004

AbstractA chelating fibrous polymer with metal complexing ability was prepared by partial conversion of the nitrile groups of melana (an acrylonitrile‐based synthetic fiber) into amidoxime groups C(NH2) = NOH using a solution of 3% hydroxylamine in methanol by refluxing at 80°C. The molar ratio of NH2OH/CN and the reaction time were adjusted to values of 0.9 and 2 h, respectively. The amidoximated polyacrylonitrile fiber with a 2.89 meq/g ion‐exchange capacity functions as an efficient chelating adsorbent for palladium ions. The pH dependence, the contact time, and the temperature of palladium ion retention from a model solution on amidoximated acrylic fiber were studied. The fibrous chelating adsorbent exhibited high affinity for palladium ions in acidic solution (pH = 2–6) at high temperature (50–60°C). The values of parametersqmandKL(from the Langmuir equation) determined at different temperatures of adsorption and the thermodynamic quantities ΔG, ΔH,and ΔSwere calculated. The adsorbed palladium ions can be quantitatively desorbed by elution with a 0.3% hydrochloric solution of thiourea. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3730–3735, 2004
Influence of quaternary ammonium salt addition on the surface activity of polyacrylic dispersants
Authors: Pantchev I. , Hunkeler D. J. 
Published: April 2004

AbstractA variety of poly(alkyl methacrylate‐co‐acrylic acid) (PS) copolymers were synthesized under conditions resembling those used in industrial processes. The interfacial tension dependence on the composition, the concentration of the polymers, and the presence of water‐soluble quaternary ammonium salt (octadecyltrimethylammonium chloride) were investigated. The studies reveal that the presence of a quaternary ammonium salt decreases the interfacial tension to a high degree and improves the dispersing properties of the synthesized copolymers. Some examples of using PS copolymer with 15 mol % acrylic acid content as a dispersant in inverse suspension copolymerization process of acrylamide and acrylic acid are presented. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3736–3743, 2004
Thermal and flow property–morphology relationship of sugarcane bagasse fiber‐filled polyamide 6 blends
Authors: Dweiri R. , Azhari C. H. 
Published: April 2004

AbstractThe structure–property relationship of sugarcane bagasse fiber‐filled polyamide 6 blends at different blend compositions has been investigated. Blends were prepared in the composition of wt % PA6/wt % bagasse as follows: 98/2, 95/5, and 90/10 for three fiber length ranges (<100, <250, and <500 μm) using a twin‐screw extruder. Thermal properties were evaluated by measuring the glass transition temperature Tg, enthalpy of fusion ΔHf, crystallinity Xc and thermogravimetry, TG. Results showed that Tg of the composites changed with change in fiber loading and length. The Xc as well as ΔHf of the blends reduced to almost half its value for the neat PA6. The thermogravimetric curves TG showed that the thermal stability of the composites was lower than that of the neat PA6. Rheological properties were studied as a function of fiber loading, fiber length, shear rate, and temperature. The viscosity of composites increased with increasing fiber loading and length at low shear rates but decreased below that of neat PA6 at high shear rates. It was also found to be temperature sensitive, and influenced by fiber lengths particularly at higher temperatures. The morphology of the blends was studied using a Leica laser scanning confocal microscopy at two different regions: at the wall, and the core. The micrographs of the blends showed that fibers present in the form of bundles were found at the wall of the extrudates and increased in volume with increase in both length and concentration, at the same temperature and shear stress. In the core region, there is laminar flow, presenting striation morphology, with the omnipresent bundles of fibers dispersed in the matrix. At higher shear rates, the bundles were pushed to the wall. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3744–3754, 2004
The diffusion of gases in semicrystalline polyethylene and its melt
Authors: Kozlov G. V. , Zaikov G. E. 
Published: April 2004

AbstractThe fractal analysis and the cluster model of the polymer amorphous structure make it possible to account for a change in the diffusion coefficient in polyethylene both above and below the melting temperature. The proposed interpretation explains the diffusivity jump at the melting point as resulting from the disintegration of local‐order regions. The formation of these regions is due to polyethylene crystallization. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3761–3763, 2004
Successful reproduction of the introduced slider turtle (Trachemys scripta elegans) in the South of France
Authors: Cadi Antoine , Delmas Virginie , Prévot‐Julliard Anne‐Caroline , Joly Pierre , Pieau Claude , Girondot Marc 
Published: April 2004

Abstract
Massive importation of slider turtles (Trachemys scripta elegans) as a pet in France over the past few decades has been followed by the release of many of these turtles into natural environments. T. scripta elegans is now widely distributed in France.
This paper reports on the successful reproduction of this species in France, with confirmed production of both sexes from nests incubated in the wild. These results indicate that the turtle T. scripta elegans can reproduce in the wild and that its long‐term persistence is possible in France.
The potential impact of this invasive species in natural ecosystems warrants future study. Meanwhile, authorities are strongly encouraged to educate the public to the potential danger of exotic species introduction for local ecosystems and to capture and remove this species from wetlands in southern Europe.
Copyright © 2004 John Wiley & Sons, Ltd.
Effects of flow variation on channel and floodplain biota and habitats of the Sacramento River, California, USA
Authors: Sommer Ted R. , Harrell William C. , Solger Anke Mueller , Tom Brad , Kimmerer Wim 
Published: April 2004

Abstract
Despite progress in the development of conceptual models of river processes, the validation and application of these models to conservation may be limited by a deficit of tools for intermediate‐scale (1–100km) reaches. A model was developed to examine the effect of variation in flow on the responses of two trophic levels in a large temperate river (Sacramento River) and its seasonal floodplain (Yolo Bypass). Field data and hydrologic simulations were evaluated for three hydrologically diverse years.
The simulations showed much more hydrologic variability in the floodplain than the river, with greater total surface and shallow area, longer hydraulic residence times, and lower water velocities for the floodplain.
Chlorophyll a levels were significantly higher in the floodplain than in the river, and were negatively associated with flow. These results were consistent with longer hydraulic residence times, increased surface area of shallow water, and warmer water temperatures.
Copepods and cladoceran densities were similar in the river and its floodplain, and were mostly negatively associated with flow.
There were significantly higher densities of Diptera and terrestrial invertebrates in the floodplain than the river. Diptera densities in the floodplain were positively associated with flow.
These results provide evidence of the incremental value of floodplain habitat to the conservation of large rivers. In particular, it appears that providing river–floodplain connectivity can enhance production of lower trophic levels at relatively rapid time scales, probably benefitting secondary consumers, including Chinook salmon (Onchyrhynchus tshawytscha).
Copyright © 2004 John Wiley & Sons, Ltd.
Disruption of transforming growth factor β signaling and profibrotic responses in normal skin fibroblasts by peroxisome proliferator–activated receptor γ
Authors: Ghosh Asish K. , Bhattacharyya Swati , Lakos Gabriella , Chen Shu‐Jen , Mori Yasuji , Varga John 
Published: April 2004

AbstractObjectiveIn fibroblasts, transforming growth factor β (TGFβ) stimulates collagen synthesis and myofibroblast transdifferentiation through the Smad intracellular signal transduction pathway. TGFβ‐mediated fibroblast activation is the hallmark of scleroderma and related fibrotic conditions, and disrupting the intracellular TGFβ/Smad signaling may provide a novel approach to controlling fibrosis. Because of its potential role in modulating inflammatory and fibrotic responses, we examined the expression of the nuclear hormone receptor peroxisome proliferator–activated receptor γ (PPARγ) in normal skin fibroblasts and its effect on TGFβ‐induced cellular responses.MethodsThe expression and activity of PPARγ in normal dermal fibroblasts were examined by Northern and Western blot analyses, immunocytochemistry, flow cytometry, and transient transfections with reporter constructs. The same approaches were used to evaluate the effects of PPARγ activation by naturally occurring and synthetic ligands on collagen synthesis and α‐smooth muscle actin (α‐SMA) expression. Modulation of Smad‐mediated transcriptional responses was examined by transient transfection assays using wild‐type and dominant‐negative PPARγ expression constructs.ResultsThe PPARγ receptor was expressed and fully functional in quiescent normal skin fibroblasts. Whereas ligand activation of cellular PPARγ resulted in modest suppression of basal collagen gene expression, it abrogated TGFβ‐induced stimulation in a concentration‐dependent manner. This response was mimicked by overexpressing PPARγ in fibroblasts, and was blocked by a selective antagonist of PPARγ signaling or by transfection of fibroblasts with dominant‐negative PPARγ constructs. Furthermore, PPARγ ligands abrogated TGFβ‐induced expression of α‐SMA, a marker of myofibroblasts. Stimulation of Smad‐dependent transcriptional responses by TGFβ was suppressed by PPARγ despite the absence of a consensus PPARγ‐response element in the targeted promoters. Ligand‐induced activation of fibroblast PPARγ had no effect on protein expression of cellular Smad3 or Smad7.ConclusionBy abrogating of TGFβ‐induced stimulation of collagen gene expression, myofibroblast transdifferentiation, and Smad‐dependent promoter activity in normal fibroblasts, PPARγ may play a physiologic role in the regulation of the profibrotic response. Furthermore, our results suggest that PPARγ activation by pharmacologic agonists may represent a novel approach to the control of fibrosis in scleroderma.
The prevalence, onset, and clinical significance of antiphospholipid antibodies prior to diagnosis of systemic lupus erythematosus
Authors: McClain Micah T. , Arbuckle Melissa R. , Heinlen Latisha D. , Dennis Gregory J. , Roebuck Jon , Rubertone Mark V. , Harley John B. , James Judith A. 
Published: April 2004

AbstractObjectiveTo determine whether antiphospholipid antibodies (aPL) occur before the diagnosis of systemic lupus erythematosus (SLE) and before initial clotting events, and whether their presence early in the disease course influences clinical outcome.MethodsSerum samples obtained from 130 lupus patients before and after SLE diagnosis were screened for IgG and IgM aPL using an anticardiolipin (aCL) enzyme‐linked immunosorbent assay. Medical records of all patients were carefully reviewed for data on the time of onset of SLE features meeting clinical criteria and on disease manifestations.ResultsTwenty‐four patients (18.5%) were positive for IgG and/or IgM aCL prior to SLE diagnosis. Anticardiolipin antibodies appeared from 7.6 years prior to SLE diagnosis to within the same month as SLE diagnosis, with a mean onset occurring 3.0 years before SLE diagnosis. Additionally, aCL presence early in the disease process seemed to predict a more severe clinical outcome; these patients eventually met an average of 6.1 of the 11 classification criteria for SLE, compared with 4.9 criteria for other patients (P < 0.001). The early aCL‐positive population also had more frequent renal disease, central nervous system disease, thrombocytopenia, and clotting events. In this population, aCL preceded initial thrombotic events by a mean of 3.1 years.ConclusionAnticardiolipin antibodies in SLE patients tend to precede initial clotting events by several years. Furthermore, the presence of early, prediagnosis aPL seems to herald a more varied, severe clinical course with earlier onset in patients with SLE.
Comparison of ultrasonographic assessment of synovitis and joint vascularity with radiographic evaluation in a randomized, placebo‐controlled study of infliximab therapy in early rheumatoid arthritis
Authors: Taylor P. C. , Steuer A. , Gruber J. , Cosgrove D. O. , Blomley M. J. K. , Marsters P. A. , Wagner C. L. , McClinton C. , Maini R. N. 
Published: April 2004

AbstractObjectiveTo investigate sensitive ultrasonographic imaging methods for detection of synovial thickness and vascularity to discriminate between patients with early rheumatoid arthritis (RA) receiving infliximab + methotrexate (MTX) versus placebo + MTX over 18 weeks, and to compare the relationship between synovial thickening and vascularity at baseline and radiologic damage to joints of the hands and feet at 54 weeks.MethodsPatients with early RA (duration <3 years) receiving stable dosages of MTX were randomly assigned to receive blinded infusions of 5 mg/kg infliximab (n = 12) or placebo (n = 12) at weeks 0, 2, 6, and then every 8 weeks until week 46. At baseline and week 18, clinical assessments were performed, and metacarpophalangeal joints were assessed by high‐frequency ultrasonography and power Doppler ultrasonography measurements. Radiographs of the hands and feet taken at baseline and at 54 weeks were evaluated using the van der Heijde modification of the Sharp method (vdH‐Sharp score).ResultsUsing changes in the total vdH‐Sharp score over 54 weeks and changes in synovial thickening and joint vascularity at 18 weeks, we were able to distinguish those patients receiving infusions of infliximab + MTX from those receiving placebo + MTX. Sonographic measurements of synovial thickening and vascularity at baseline in the placebo + MTX group demonstrated clear relationships with the magnitude of radiologic joint damage at week 54. Infliximab + MTX treatment abolished these relationships.ConclusionThe delay or reversal of inflammatory and joint‐destructive mechanisms in patients with early RA was already apparent following 18 weeks of treatment with infliximab + MTX and was reflected in radiologic changes at 54 weeks.
The role of subchondral bone remodeling in osteoarthritis: Reduction of cartilage degeneration and prevention of osteophyte formation by alendronate in the rat anterior cruciate ligament transection model
Authors: Hayami Tadashi , Pickarski Maureen , Wesolowski Gregg A. , Mclane Julia , Bone Ashleigh , Destefano James , Rodan Gideon A. , Duong Le T. 
Published: April 2004

AbstractObjectiveIt has been suggested that subchondral bone remodeling plays a role in the progression of osteoarthritis (OA). To test this hypothesis, we characterized the changes in the rat anterior cruciate ligament transection (ACLT) model of OA and evaluated the effects of alendronate (ALN), a potent inhibitor of bone resorption, on cartilage degradation and on osteophyte formation.MethodsMale Sprague‐Dawley rats underwent ACLT or sham operation of the right knee. Animals were then treated with ALN (0.03 and 0.24 μg/kg/week subcutaneously) and necropsied at 2 or 10 weeks postsurgery. OA changes were evaluated. Subchondral bone volume and osteophyte area were measured by histomorphometric analysis. Coimmunostaining for transforming growth factor β (TGFβ), matrix metalloproteinase 9 (MMP‐9), and MMP‐13 was performed to investigate the effect of ALN on local activation of TGFβ.ResultsALN was chondroprotective at both dosages, as determined by histologic criteria and collagen degradation markers. ALN suppressed subchondral bone resorption, which was markedly increased 2 weeks postsurgery, and prevented the subsequent increase in bone formation 10 weeks postsurgery, in the untreated tibial plateau of ACLT joints. Furthermore, ALN reduced the incidence and area of osteophytes in a dose‐dependent manner. ALN also inhibited vascular invasion into the calcified cartilage in rats with OA and blocked osteoclast recruitment to subchondral bone and osteophytes. ALN treatment reduced the local release of active TGFβ, possibly via inhibition of MMP‐13 expression in articular cartilage and MMP‐9 expression in subchondral bone.ConclusionSubchondral bone remodeling plays an important role in the pathogenesis of OA. ALN or other inhibitors of bone resorption could potentially be used as disease‐modifying agents in the treatment of OA.
Monitoring neutrophil activation in juvenile rheumatoid arthritis by S100A12 serum concentrations
Authors: Foell Dirk , Wittkowski Helmut , Hammerschmidt Inga , Wulffraat Nico , Schmeling Heinrike , Frosch Michael , Horneff Gerd , Kuis Wietse , Sorg Clemens , Roth Johannes 
Published: April 2004

AbstractObjectivePhagocytes are extensively involved in the synovial inflammation associated with chronic arthritis. The aim of our study was to determine neutrophil activation in juvenile rheumatoid arthritis (JRA) by analyzing S100A12 (EN‐RAGE; calgranulin C), a proinflammatory protein secreted by human neutrophils.MethodsS100A12 serum concentrations were determined in 124 patients with chronic active polyarticular‐, oligoarticular‐, or systemic‐onset JRA. S100A12 was also analyzed in synovial fluid obtained from 22 patients. Changes in S100A12 levels in response to anti–tumor necrosis factor α (anti‐TNFα) therapy, intraarticular injections of corticosteroids, and methotrexate (MTX) treatment were analyzed. Forty‐five patients were followed up after successful antiinflammatory treatment, for a mean period of 2.8 years.ResultsThe mean serum level of S100A12 was 395 ng/ml in patients with active polyarticular JRA and 325 ng/ml in patients with active oligoarticular JRA (normal <120 ng/ml). The level of S100A12 was ∼10‐fold higher in synovial fluid than in serum, indicating release at sites of local inflammation. In patients with systemic‐onset JRA, the mean level of S100A12 was 3,700 ng/ml. Moreover, serum levels decreased in response to different antiinflammatory therapies (i.e., intraarticular injections of corticosteroids, MTX, or etanercept). S100A12 levels were elevated in 20 patients who experienced disease flares after the initial induction of remission, even weeks before the relapses became clinically apparent.ConclusionS100A12 serum concentrations indicate neutrophil activation in JRA and correlate with disease activity. S100A12 may indicate synovial inflammation even when other signs of arthritis are absent. Its function as a proinflammatory factor secreted by activated neutrophils makes this protein a potential target for future therapies.
Signs of first‐degree heart block occur in one‐third of fetuses of pregnant women with anti–SSA/Ro 52‐kd antibodies
Authors: Sonesson Sven‐Erik , Salomonsson Stina , Jacobsson Lilly‐Ann , Bremme Katarina , Wahren‐Herlenius Marie 
Published: April 2004

AbstractObjectiveTo prospectively investigate the development of fetal heart block in anti–SSA/Ro 52‐kd–positive women, and to evaluate the usefulness of serial Doppler echocardiography in detecting early signs of congenital heart block.MethodsTwenty‐four women with anti–SSA/Ro 52‐kd antibodies and consequently increased risk for fetal heart block were followed up weekly, between 18 and 24 weeks of gestation, with two Doppler echocardiographic methods designed to estimate the time delay between hemodynamic events caused by atrial and ventricular depolarizations. Two hundred eighty‐four women with normal pregnancies served as controls. Anti–Ro 52‐kd, anti–Ro 60‐kd, and anti‐La antibodies were investigated by immunoblotting and enzyme‐linked immunosorbent assay using recombinant proteins.ResultsIn anti–Ro 52‐kd–positive women, fetal atrioventricular (AV) time intervals were longer and heart rates were slightly lower compared with those in controls. Eight of 24 fetuses had signs of first‐degree block. One of these fetuses had progression to complete block, and another showed recovery from second‐degree block to first‐degree block with betamethasone treatment. In the remaining 6 fetuses, spontaneous normalization occurred before or shortly after birth. Fetuses with normal AV time intervals at 18–24 weeks had normal electrocardiographic results at birth.ConclusionAnti–Ro 52‐kd–positive pregnant women frequently carry fetuses with Doppler echocardiographic signs of first‐degree AV block. These blocks revert spontaneously in the majority of fetuses, but progression to a more severe degree of block may occur in some. Serial Doppler echocardiographic measurement of AV time intervals is suggested as a useful method for surveillance of these high‐risk pregnancies.
Musculoskeletal abnormalities of the forearm in patients with juvenile idiopathic arthritis relate mainly to bone geometry
Authors: Roth Johannes , Palm Christian , Scheunemann Ingo , Ranke Michael B. , Schweizer Roland , Dannecker Guenther E. 
Published: April 2004

AbstractObjectiveAlterations of the skeletal system, including reduced bone mineral density, increased frequency of fractures, and changes in markers of bone metabolism, have been described in juvenile idiopathic arthritis (JIA), but measurement of volumetric bone density and bone geometry is not possible with the techniques used in most studies. This study was undertaken to obtain a more detailed understanding of the musculoskeletal system in JIA by analyzing bone density, bone geometry, and muscle force as the most important factor in bone development.MethodsThe technique of peripheral quantitative computed tomography was used in a cross‐sectional study of 57 children with the oligoarticular, polyarticular, or systemic form of JIA. Density of trabecular and cortical bone as well as geometric parameters of bone and muscle were measured at the forearm.ResultsChildren in all subgroups had significantly reduced muscle cross‐sectional area, which was strongly correlated with muscle force and abnormalities in geometric parameters of bone, including a significant reduction in cortical thickness. Trabecular density was affected only in the polyarticular JIA group, and cortical density was normal in all subgroups.ConclusionOur results suggest that an important problem in JIA is the lack of muscle mass and force, together with abnormal bone geometry. The thinned bony cortices might predispose to fractures even though cortical bone density itself is normal. These results might have implications with regard to therapeutic approaches to preserve musculoskeletal integrity in JIA.