bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of cholesteric thermotropic liquid crystalline polyesters
Authors: Jadhav Sushilkumar A. , Chougule Rahul R. , Shinde Yogesh A. , Chavan N. N. 
Published: October 2006

AbstractCholesteric liquid crystalline polyesters were successfully synthesized from isosorbide, methyl hydroquinone, and isophthaloyl chloride. Homo/copolyesters were synthesized by the solution polycondensation method, for which a mild organic base such as pyridine was employed. Inherent viscosities of polyesters P‐3–P‐5 were in the range of 0.31–0.39 dL/g at 25°C in chloroform, and polyesters P‐1 and P‐2 were insoluble in chloroform. Homo/copolyesters based on isosorbide, methyl hydroquinone, and isophthalic acid had thermal stability at more than 300°C on the basis of 10% weight loss. The thermotropic liquid crystalline properties were examined by differential scanning calorimetry and polarizing optical microscopy. Wide‐angle X‐ray diffraction study demonstrated that polyesters P‐1, P‐2, and P‐3 were semicrystalline, whereas the degree of crystallinity of polyesters P‐4 and P‐5 was less than 5%. Copolyester P‐4 showed formation of a yellow iridescent streak at 209°C on heating and development of a Grandjean texture at 270°C on heating. These are typical textures of the cholesteric liquid crystalline phase. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1232–1237, 2007
New approach for the preparation of nanoporous polyorganosilicate low‐k films
Authors: Xi Kai , Guo Rui , Weng Yangyang , He Hui , Shao Qiang , Cai Jie , Chen Qingmin , Yu Xuehai , Jia Xudong 
Published: October 2006

AbstractThe distribution of pores and the mechanical properties of materials are the key factors in preparing satisfactory low‐k films. In the present study, a kind of silsesquioxane‐polyethylene glycol (SSQ‐PEG) was synthesized and used as a template to make the distribution of pores more even in the low‐k films. The crosslinking density of films could be adjusted by the sol‐gel of tetramethoxysilane/dimethoxydimethylsilane with various proportions. The porosity of films could also be adjusted with different proportions of pendant PEG chains introduced. A dielectric constant as low as 2.1 had been achieved for nanoporous polyorganosilicate films with good tenacity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1238–1243, 2007
Effects of thermal aging on fatigue of carbon black–reinforced EPDM rubber
Authors: Chou Hsoung‐Wei , Huang Jong‐Shin , Lin Shih‐Ting 
Published: October 2006

AbstractDeterioration of the parameters measuring the fatigue of rubber compounds as a result of thermal aging was investigated. The energy to break, tear strength, fatigue life, and fatigue crack propagation rate of EPDM rubber compounds reinforced with three different types of carbon black before and after different periods of thermal aging were measured and compared through a series of static and cyclic loading tests. The experimental results indicated that the fatigue resistance of EPDM rubber compounds with different types of carbon black was consistently reduced because of changes in the molecular structure and crosslink density as a result of thermal aging. Meanwhile, the intrinsic flaws of carbon black–reinforced EPDM rubber compounds after 6 months of thermal aging were smaller, regardless of the type of carbon black. Therefore, the effects of thermal aging on the fatigue of rubber compounds are significant and should be taken into account in designing rubber components. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1244–1251, 2007
Analysis of network structure formed in styrene–butadiene rubber cured with sulfur/TBBS system
Authors: Marzocca A. J. , Mansilla M. A. 
Published: October 2006

AbstractSeveral styrene–butadiene rubber (SBR) compounds were prepared with different cure systems based on sulfur and TBBS (N‐t‐butyl‐2‐benzothiazole sulfenamide), varying the amount of sulfur and accelerator between 0.5 and 2.5 phr in the formulation. Torque curves, measured with a moving die rheometer at temperatures at 433 K, were used to characterize the vulcanization. The time to achieve the maximum torque, t100%, was evaluated for each sample, and this time was set to vulcanize sheets at 433 K. The density and type of elastically active crosslinks of each cured sample were evaluated by means of swelling measurements and were related to the vulcanizing system. Finally, the rheometer data were analyzed considering the network structure formed during vulcanization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1105–1112, 2007
Solid‐state polymerization of poly(ethylene 2,6‐naphthalate)
Authors: Duh Ben 
Published: October 2006

AbstractThe solid‐state polymerization (SSP) of poly (ethylene 2,6‐naphthalate) (PEN) was studied and compared with that of poly(ethylene terephthalate) (PET). The SSP of PEN, like that of PET, could be satisfactorily described with a modified second‐order kinetic model, which was based on the assumptions that part of the end groups were inactive during SSP and that the overall SSP followed second‐order kinetics with respect to the active end‐group concentration. The proposed rate equation fit the data of the SSP of PEN quite well under various conditions. PEN prepolymers in pellet and cube forms with intrinsic viscosities (IVs) ranging from 0.375 to 0.515 dL/g, various particle sizes, and various carboxyl concentrations were solid‐state polymerized at temperatures ranging from 240 to 260°C to study the effects of various factors. The SSP data obtained in this study could be readily applied to the design of commercial PEN SSP processes. Because PEN and PET share the same SSP mechanism, in general, the SSP behaviors of PEN are similar to those of PET. Thus, the SSP rate of PEN increased with increasing temperature, increasing prepolymer IV, and decreasing prepolymer particle size. However, because of the much higher barrier properties of PEN, the prepolymer particle size and carboxyl concentration had much greater effects on the SSP of PEN than on the SSP of PET. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1075–1084, 2007
Miscibility behavior of blend of polyesteramides of linseed oil and dehydrated castor oil with poly(methacrylic acid)
Authors: Ashraf S. M. , Ahmad Sharif , Riaz Ufana , Alam Manawwer , Sharma H. O. 
Published: October 2006

AbstractBlending of two polymers in solution is a simple and cost‐effective technique to improve upon the physical and mechanical properties of the component polymers through synergism. To obtain maximum synergy in their properties, the component polymers should be miscible with each other on molecular scale. Polymer blends of complex physicomechanical properties are being actively investigated. Poly(methacrylic acid) (PMAA), a commercial polymer, yields transparent, hard, brittle, and water‐sensitive films. It has been blended with natural polymers like dextran, collagen, and gelatin to obtain films with improved physical and mechanical characteristics. Polyesteramides, which are easily synthesized from vegetable seeds oil, a sustainable resource, have found application in surface coatings. These oligomeric products do not make free standing films in the ambient condition. The polyesteramides from vegetable seeds oil can be used to obtain blend with PMMA of improved mechanical and water absorption properties. In this study, linseed oil polyesteramide (LOPEA) and dehydrated castor oil polyesteramide (DCPEA), the source oils with different unsaturation in their fatty acid chains, were blended with PMAA through mixing in solution in the ratio DCPEA/LOPEA: PMAA as 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, and 20/80. In the first instance, the miscibility of the two components was investigated in solution by viscosity and ultrasonic measurements and in solid phase through differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Moisture absorption by the blend was also studied. DCPEA and LOPEA show immiscibility with PMAA in solution phase while LOPEA with more unsaturation in the fatty acid chain of the oil was found more immiscible than DCPEA. DCPEA shows a narrow miscibility window in the solid phase while LOPEA was found immiscible with PMAA in the solid phase too. Uptake of moisture was found to be markedly reduced in the blends of DCPEA/LOPEA with PMAA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1367–1374, 2007:
Human cranial anatomy and the differential preservation of population history and climate signatures
Authors: Harvati Katerina , Weaver Timothy D. 
Published: October 2006

AbstractCranial morphology is widely used to reconstruct evolutionary relationships, but its reliability in reflecting phylogeny and population history has been questioned. Some cranial regions, particularly the face and neurocranium, are believed to be influenced by the environment and prone to convergence. Others, such as the temporal bone, are thought to reflect more accurately phylogenetic relationships. Direct testing of these hypotheses was not possible until the advent of large genetic data sets. The few relevant studies in human populations have had intriguing but possibly conflicting results, probably partly due to methodological differences and to the small numbers of populations used. Here we use three‐dimensional (3D) geometric morphometrics methods to test explicitly the ability of cranial shape, size, and relative position/orientation of cranial regions to track population history and climate. Morphological distances among 13 recent human populations were calculated from four 3D landmark data sets, respectively reflecting facial, neurocranial, and temporal bone shape; shape and relative position; overall cranial shape; and centroid sizes. These distances were compared to neutral genetic and climatic distances among the same, or closely matched, populations. Results indicate that neurocranial and temporal bone shape track neutral genetic distances, while facial shape reflects climate; centroid size shows a weak association with climatic variables; and relative position/orientation of cranial regions does not appear correlated with any of these factors. Because different cranial regions preserve population history and climate signatures differentially, caution is suggested when using cranial anatomy for phylogenetic reconstruction. Anat Rec Part A, 2006. © 2006 Wiley‐Liss, Inc.
Risedronate decreases biochemical markers of cartilage degradation but does not decrease symptoms or slow radiographic progression in patients with medial compartment osteoarthritis of the knee: Results of the two‐year multinational knee osteoarthritis structural arthritis study
Authors: Bingham Clifton O. , Buckland‐Wright J. Chris , Garnero Patrick , Cohen Stanley B. , Dougados Maxime , Adami Silvano , Clauw Daniel J. , Spector Timothy D. , Pelletier Jean‐Pierre , Raynauld Jean‐Pierre , Strand Vibeke , Simon Lee S. , Meyer Joan M. , Cline Gary A. , Beary John F. 
Published: October 2006

AbstractObjectiveBisphosphonates have slowed the progression of osteoarthritis (OA) in animal models and have decreased pain in states of high bone turnover. The Knee OA Structural Arthritis (KOSTAR) study, which is the largest study to date investigating a potential structure‐modifying OA drug, tested the efficacy of risedronate in providing symptom relief and slowing disease progression in patients with knee OA.MethodsThe study group comprised 2,483 patients with medial compartment knee OA and 2–4 mm of joint space width (JSW), as determined using fluoroscopically positioned, semiflexed‐view radiography. Patients were enrolled in 2 parallel 2‐year studies in North America and the European Union. These studies evaluated the efficacy of risedronate at dosages of 5 mg/day, 15 mg/day, 35 mg/week (in Europe), and 50 mg/week (in North America) compared with placebo in reducing signs and symptoms, as measured by the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and patient global assessment (PGA) scores, and in slowing radiographic progression.ResultsA reduction of ∼20% in signs and symptoms, as measured by WOMAC subscales and PGA scores, was observed in all groups, with no treatment effect of risedronate demonstrated. Risedronate did not significantly reduce radiographic progression as measured by decreased JSW or using a dichotomous definition of progression (joint space loss of ≥0.6 mm). Thirteen percent of patients receiving placebo demonstrated significant disease progression over 2 years. A dose‐dependent reduction in the level of C‐terminal crosslinking telopeptide of type II collagen, a cartilage degradation marker associated with progressive OA, was seen in patients who received risedronate. No increase in the number of adverse events was demonstrated for risedronate compared with placebo.ConclusionAlthough risedronate (compared with placebo) did not improve signs or symptoms of OA, nor did it alter progression of OA, a reduction in the level of a marker of cartilage degradation was observed. A sustained clinically relevant improvement in signs and symptoms was observed in all treatment and placebo groups.
Antiviral therapy for hepatitis C virus–associated mixed cryoglobulinemia vasculitis: A long‐term followup study
Authors: Saadoun David , Resche‐Rigon Mathieu , Thibault Vincent , Piette Jean‐Charles , Cacoub Patrice 
Published: October 2006

AbstractObjectiveTo evaluate the long‐term efficacy of anti–hepatitis C virus (HCV) therapy in patients with HCV‐associated mixed cryoglobulinemia (HCV‐MC) vasculitis and to assess the factors associated with clinical remission of MC.MethodsThis was a single‐center study of 72 consecutive patients who received treatment with IFN alfa‐2b (3 million IU 3 times a week; n = 32 patients) or PEGylated IFN alfa‐2b (PEG–IFN alfa‐2b) (1.5 μg/kg/week; n = 40 patients), both in combination with oral ribavirin (600–1,200 mg/day), for at least 6 months. Logistic regression was used to assess factors associated with clinical remission of MC.ResultsThe mean ± SD duration of followup after discontinuation of antiviral therapy was 39.7 ± 24.4 months. Eight deaths (11.1% of patients) occurred during the study, primarily as a result of cardiovascular disease, liver disease, or infection. A complete clinical response of the MC occurred in 45 patients (62.5%), a sustained virologic response occurred in 58.3%, and cryoglobulins cleared in 45.8%. Compared with patients treated with IFN alfa‐2b plus ribavirin, those receiving PEG–IFN alfa‐2b plus ribavirin had a higher sustained clinical (67.5% versus 56.3%), virologic (62.5% versus 53.1%), and immunologic (57.5% versus 31.3%) response, regardless of HCV genotype and viral load. In multivariate analyses, an early virologic response (odds ratio 3.53 [95% confidence interval 1.18–10.59]) was independently associated with a complete clinical response of MC. A glomerular filtration rate ≤70 ml/minute (odds ratio 0.18 [95% confidence interval 0.05–0.67]) was negatively associated with a complete clinical response of MC.ConclusionPEG–IFN alfa‐2b plus ribavirin should be considered as induction therapy for HCV‐MC vasculitis. An early virologic response and the absence of renal insufficiency are the key factors in the clinical response.
RhoA‐mediated, tumor necrosis factor α–induced activation of NF‐κB in rheumatoid synoviocytes: Inhibitory effect of simvastatin
Authors: Xu Hanshi , Liu Peng , Liang Liuqin , Danesh Farhad R. , Yang Xiuyan , Ye Yijin , Zhan Zhongping , Yu Xueqing , Peng Hui , Sun Lin 
Published: October 2006

AbstractObjectiveIncreasing evidence indicates that RhoA may play a central role in the inflammatory response. This study was conducted to examine the role of RhoA in mediating the activation of NF‐κB in tumor necrosis factor α (TNFα)–stimulated rheumatoid synoviocytes, and to evaluate the modulatory effects of statins on the TNFα‐induced activation of RhoA and NF‐κB and the secretion of proinflammatory cytokines by rheumatoid synoviocytes.MethodsRheumatoid synoviocytes obtained from patients with active rheumatoid arthritis were stimulated with TNFα and incubated with simvastatin (SMV) (1 μM). RhoA activity was assessed by a pull‐down assay. NF‐κB DNA binding activity and nuclear translocation of NF‐κB were measured by a sensitive multiwell colorimetric assay and confocal fluorescence microscopy, respectively.ResultsTNFα stimulation elicited a robust increase in RhoA activity in a dose‐dependent manner, and SMV mitigated this increase. TNFα also hastened NF‐κB nuclear translocation of subunit p65 and increased DNA binding activity, luciferase reporter gene expression, degradation of IκB, and secretion of interleukin‐1β (IL‐1β) and IL‐6. SMV prevented the increase in NF‐κB activation and rise in IL‐1β and IL‐6 levels induced by TNFα, whereas mevalonate and geranylgeranyl pyrophosphate reversed the inhibitory effects of SMV on activation of NF‐κB and RhoA. Furthermore, cotransfection with a dominant‐negative mutant of RhoA demonstrated that the TNFα‐induced signaling pathway involved sequential activation of RhoA, leading to NF‐κB activation and, ultimately, to secretion of cytokines.ConclusionThis study identifies RhoA as the key regulator of TNFα‐induced NF‐κB activation, which ultimately results in the secretion of proinflammatory cytokines in rheumatoid synoviocytes. The findings provide a new rationale for the antiinflammatory effects of statins in inflammatory arthritis.
Glycan analysis of monoclonal antibodies secreted in deposition disorders indicates that subsets of plasma cells differentially process IgG glycans
Authors: Omtvedt Lone A. , Royle Louise , Husby Gunnar , Sletten Knut , Radcliffe Catherine M. , Harvey David J. , Dwek Raymond A. , Rudd Pauline M. 
Published: October 2006

AbstractObjectiveTo compare the glycosylation of polyclonal serum IgG heavy chains in a patient with rheumatoid arthritis (RA) with that of monoclonal serum IgG heavy chains in the same patient during an episode of heavy‐chain deposition disease (HCDD), to establish whether glycosylation processing is specific for subsets of B cells.MethodsSerum IgG was purified using a HiTrap protein G column. Immunoglobulins were run on sodium dodecyl sulfate–polyacrylamide gel electrophoresis gels, and IgG glycans were isolated from gel bands and fluorescently labeled. Glycans were analyzed by normal‐phase high‐performance liquid chromatography and by liquid chromatography–electrospray ionization–mass spectrometry.ResultsThe glycosylation of serum immunoglobulins from a patient with seronegative RA and HCDD was analyzed. The predominant immunoglobulin was a truncated glycosylated γ3 heavy chain, and a small amount of polyclonal IgG was also present. The glycan profile showed that the monoclonal γ3 heavy chain contained fully galactosylated biantennary glycans with significantly less fucose but more sialic acid than in IgG3 from healthy controls. In contrast, the polyclonal IgG showed an RA‐like profile, with a predominance of fucosylated biantennary glycans and low levels of galactosylation. The glycan profile of serum IgG obtained from the same patient during disease remission resembled a typical RA profile.ConclusionThese data indicate that different types of B cells process a particular set of IgG glycoforms.
Impaired skeletal development in interleukin‐6–transgenic mice: A model for the impact of chronic inflammation on the growing skeletal system
Authors: De Benedetti Fabrizio , Rucci Nadia , Del Fattore Andrea , Peruzzi Barbara , Paro Rita , Longo Maurizio , Vivarelli Marina , Muratori Flaminia , Berni Silvia , Ballanti Paola , Ferrari Serge , Teti Anna 
Published: October 2006

AbstractObjectiveTo identify the mediator responsible for the impact of chronic inflammation on skeletal development in children (bone loss, defective peak bone mass accrual, stunted growth), we evaluated the effects of chronic interleukin‐6 (IL‐6) overexpression on the skeletons of growing prepubertal mice.MethodsWe studied IL‐6–transgenic mice that had high circulating IL‐6 levels since birth. Trabecular and cortical bone structure were analyzed by microcomputed tomography. Epiphyseal ossification, growth plates, and calvariae were studied by histology/histomorphometry. Osteoclastogenesis, osteoblast function/differentiation, and the effects of IL‐6 on bone cells were studied in vitro. Osteoblast gene expression was evaluated by reverse transcriptase–polymerase chain reaction. The mineral apposition rate was evaluated dynamically in cortical bone by in vivo double fluorescence labeling.ResultsIn prepubertal IL‐6–transgenic mice, we observed osteopenia, with severe alterations in cortical and trabecular bone microarchitecture, as well as uncoupling of bone formation from resorption, with decreased osteoblast and increased osteoclast number and activity. Increased osteoclastogenesis and reduced osteoblast activity, secondary to decreased precursor proliferation and osteoblast function, were present. IL‐6–transgenic mice also showed impaired development of growth plates and epiphyseal ossification centers. Intramembranous and endochondral ossification and the mineral apposition rate were markedly affected, showing the presence of defective ossification.ConclusionChronic overexpression of IL‐6 alone induces a skeletal phenotype closely resembling growth and skeletal abnormalities observed in children with chronic inflammatory diseases, pointing to IL‐6 as a pivotal mediator of the impact of chronic inflammation on postnatal skeletal development. We hypothesize that IL‐6–modifying drugs may reduce skeletal defects and prevent the growth retardation associated with these diseases.
Efficacy and mechanism of action of turmeric supplements in the treatment of experimental arthritis
Authors: Funk Janet L. , Frye Jennifer B. , Oyarzo Janice N. , Kuscuoglu Nesrin , Wilson Jonathan , McCaffrey Gwen , Stafford Gregory , Chen Guanjie , Lantz R. Clark , Jolad Shivanand D. , Sólyom Aniko M. , Kiela Pawel R. , Timmermann Barbara N. 
Published: October 2006

AbstractObjectiveScientific evidence is lacking for the antiarthritic efficacy of turmeric dietary supplements that are being promoted for arthritis treatment. Therefore, we undertook studies to determine the antiarthritic efficacy and mechanism of action of a well‐characterized turmeric extract using an animal model of rheumatoid arthritis (RA).MethodsThe composition of commercial turmeric dietary supplements was determined by high‐performance liquid chromatography. A curcuminoid‐containing turmeric extract similar in composition to these supplements was isolated and administered intraperitoneally to female Lewis rats prior to or after the onset of streptococcal cell wall–induced arthritis. Efficacy in preventing joint swelling and destruction was determined clinically, histologically, and by measurement of bone mineral density. Mechanism of action was elucidated by analysis of turmeric's effect on articular transcription factor activation, microarray analysis of articular gene expression, and verification of the physiologic effects of alterations in gene expression.ResultsA turmeric fraction depleted of essential oils profoundly inhibited joint inflammation and periarticular joint destruction in a dose‐dependent manner. In vivo treatment prevented local activation of NF‐κB and the subsequent expression of NF‐κB–regulated genes mediating joint inflammation and destruction, including chemokines, cyclooxygenase 2, and RANKL. Consistent with these findings, inflammatory cell influx, joint levels of prostaglandin E2, and periarticular osteoclast formation were inhibited by turmeric extract treatment.ConclusionThese translational studies demonstrate in vivo efficacy and identify a mechanism of action for a well‐characterized turmeric extract that supports further clinical evaluation of turmeric dietary supplements in the treatment of RA.