bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical investigation of the performance and transport phenomena of a proton‐exchange membrane fuel cell with a wavelike gas flow channel design
Authors: Kuo Jenn‐Kun , Chang‐Jian Cai‐Wan , Chen Cha'O‐Kuang 
Published: October 2008

AbstractThis article investigates the performance of a proton‐exchange membrane fuel cell (PEMFC) with a novel wavelike gas flow channel. Numerical simulations have been performed to investigate the effect of the wavelike channel profile on the gas flow characteristics, temperature distribution, electrochemical reaction efficiency, and electrical performance. The simulation results show that compared to a conventional straight gas flow channel, the wavelike channel increases the fuel flow velocity, enhances the transport through the porous layer, and improves the temperature distribution. As a result, the PEMFC has improved fuel utilization efficiency and superior heat‐transfer characteristics. Furthermore, the results show that the wavelike gas flow channel yields a higher PEMFC output voltage and improves the maximum power density by approximately 32.5%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of a positive thermoresponsive hydrogel for drug loading and release
Authors: Wang Qifang , Li Sanming , Wang Zhongyan , Liu Hongzhuo , Li Chaojie 
Published: October 2008

AbstractA positive thermoresponsive hydrogel composed of poly(acrylic acid)‐graft‐β‐cyclodextrin (PAAc‐g‐β‐CD) and polyacrylamide (PAAm) was synthesized with the sequential interpenetrating polymer network (IPN) method for the purpose of improving its loading and release of drugs. The structure and properties of the PAAc‐g‐β‐CD/PAAm hydrogel (IPN hydrogel) were characterized with Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and swelling measurements. FTIR studies showed that the IPN hydrogel was primarily composed of an IPN of PAAc‐g‐β‐CD and PAAm. The data from DSC and swelling measurements indicated that the phase‐transition temperature or upper critical solution temperature (UCST) of the IPN hydrogel was approximately 35°C. Through the measurement of the temperature dependence of the swelling, increases in the UCST and non‐sensitivity to changes in the salt concentration were observed for the IPN hydrogel versus the normal IPN hydrogel poly(acrylic acid)/PAAm (without β‐cyclodextrin). Furthermore, the swelling/deswelling kinetics of the IPN hydrogel also exhibited an improved controllable response rate versus the normal IPN hydrogel. Ibuprofen (IBU) was chosen as the model drug for examining loading and release from the IPN hydrogel. The experimental data proved that the IPN hydrogel provided a positive drug release pattern; the IBU released faster at 37°C than at 25°C, and improved drug loading and controlled release were achieved by the IPN hydrogel versus the normal IPN hydrogel. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Cracking in poly(trimethylene terephthalate) spherulites
Authors: Yao Chenguang , Yang Guisheng 
Published: October 2008

AbstractThe crack behavior of poly(trimethylene terephthalate) spherulites was studied mainly by polarizing optical microscopy, along with scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition to the effects of temperature and constraining substrate, another important factor, film thickness, on the formation of crack was first put forward and investigated. The emergence of the first crack occurred at 120°C during cooling after crystallization at 190°C for the sample with a thickness of 31.0 μm. For the spherulites growing between glass sheets, it was interesting that the sample with a thickness of 26.0 μm exhibited the largest number of cracks measured per 200 μm of radius, whereas samples thicker than 100 μm or thinner than 1 μm did not induce the formation of crack. Also, spherulites growing between two polyimide and two Teflon sheets showed no crack. Glass sheets lubricated with silicon oil restrained the number of cracks but did not eliminate cracks. SEM revealed that the cracking was about 900 nm in width. In addition, the AFM results suggest that the cracks had a depth of at least 150 nm. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Kinetic analysis and improvement of the Williamson reaction for the synthesis of poly(ethylene glycol) propionaldehyde
Authors: Zhao Yong‐Jiang , Zhai Yan‐Qin , Ma Guang‐Hui , Su Zhi‐Guo 
Published: October 2008

AbstractPoly(ethylene glycol) (PEG) propionaldehyde is an important polymer derivative used in protein modification; it is usually synthesized by the Williamson reaction of 3‐chloropropionaldehyde diethyl acetal (CPADA) with PEG alkoxide followed by hydrolysis to deprotect the aldehyde group. However, the side reaction of the Williamson reaction has been a severe drawback leading to a low‐aldehyde‐content product. In this study, we established a kinetic model to depict the competition of the Williamson reaction and its side reaction. Based on a kinetic analysis, experiments were performed to systemically investigate the influence of the process parameters on the yield of PEG aldehyde, including the reaction solvents, reaction temperature, and molar equivalents of CPADA. The best reaction solvent was determined to be dioxane because the conversion of methoxy pol(ethylene glycol) in dioxane was higher than that in other solvents and because dioxane has low toxicity and is easily handled. The reaction temperature was set as the refluxing point of dioxane to effectively convert PEG into its alkoxide. The equivalents of CPADA were optimized to be 15 to obtain a quantitative yield of mPEG propionaldehyde and avoid wasting the reagent. The quantitative yield of mPEG propionaldehyde was achieved under these optimum conditions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Fouling reduction of a poly(ether sulfone) hollow‐fiber membrane with a hydrophilic surfactant prepared via non‐solvent‐induced phase separation
Authors: Arahman Nasrul , Maruyama Tatsuo , Sotani Tomohiro , Matsuyama Hideto 
Published: October 2008

AbstractMembrane fouling is still a crucial problem, especially in applications for water treatment. When fouling takes place on membrane surfaces, it causes flux decline, leading to an increase in production cost due to increased energy demand. The selection of the right membrane material and a special treatment of the membrane are required to avoid membrane fouling. This article reports the fouling resistance of a poly(ether sulfone) (PES) hollow‐fiber membrane modified with hydrophilic surfactant Tetronic 1307. Experiments on several methods of fouling were carried out to investigate the effect of the addition of nonionic surfactant Tetronic 1307 on membrane fouling. The effectiveness of a chemical agent [sodium hypochlorite (NaClO)] in the reduction of bovine serum albumin (BSA) deposition on the membrane surface was also evaluated. Permeation results showed that the fouling of a PES blend membrane with Tetronic 1307 was lower than that of the original PES membrane in the case of BSA filtration. A treatment with a 100 ppm NaClO solution was capable of removing BSA cake formation and effective at improving the relative permeability. The permeability of a PES blend membrane with Tetronic 1307 was almost 2 times higher than the original permeability when the membrane was treated with a 100 ppm NaClO solution because both BSA and Tetronic 1307 could be decomposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A comparative study of polypropylene nucleated by individual and compounding nucleating agents. I. Melting and isothermal crystallization
Authors: Bai Hongwei , Wang Yong , Zhang Qin , Liu Li , Zhou Zuowan 
Published: October 2008

AbstractIn this study, melting and isothermal crystallization behaviors of polypropylene (PP) nucleated with different nucleating agents (NAs) have been comparatively studied. α‐phase NA 1,3 : 2,4‐bis (3,4‐dimethylbenzylidene) sorbitol (DMDBS, Millad 3988), β‐phase NA aryl amides compound (TMB‐5), and their compounds were introduced into PP matrix, respectively. The crystallization and melting characteristics as well as the crystallization structures and morphologies of nucleated PP were studied by differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXD), and polarized light microscopy (PLM). As indicated by previous work that a few amounts of α‐phase NA (DMDBS) or β‐phase NA (TMB‐5) has apparent nucleation effect for PP crystallization. However, the crystallization of PP nucleated with compounding NAs is dependent on the content of each NA. In the sample of PP with 0.1 wt % DMDBS and 0.1 wt % TMB‐5, the nucleation efficiency of TMB‐5 is much higher than that of DMDBS and PP crystallization is mainly nucleated by TMB‐5, and in this condition, β‐phase PP is the main crystallization structure. For the sample of PP with 0.2 wt % DMDBS and 0.2 wt % TMB‐5, 0.2 wt % DMDBS has higher nucleation efficiency than 0.2 wt % TMB5, and α‐phase is the main crystalline structure in this sample. The isothermal crystallization kinetics and crystallization structure have been analyzed in detail in this work. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Interleukin‐1 drives pathogenic Th17 cells during spontaneous arthritis in interleukin‐1 receptor antagonist–deficient mice
Authors: Koenders Marije I. , Devesa Isabel , Marijnissen Renoud J. , Abdollahi‐Roodsaz Shahla , Boots Annemieke M. H. , Walgreen Birgitte , di Padova Franco E. , Nicklin Martin J. H. , Joosten Leo A. B. , van den Berg Wim B. 
Published: October 2008

AbstractObjectiveInterleukin‐1 receptor antagonist–deficient (IL‐1Ra−/−) mice spontaneously develop an inflammatory and destructive arthritis due to unopposed excess IL‐1 signaling. In this study, the role of Th17 cells and the effect of neutralization of IL‐17, IL‐1, and tumor necrosis factor α (TNFα) were investigated in this IL‐1–driven murine arthritis model.MethodsT cells isolated from IL‐1Ra−/−and wild‐type (WT) mice were stained for IL‐17 and interferon‐γ, with results assessed by fluorescence‐activated cell sorting analysis. To investigate the contribution of IL‐1 and IL‐17 in further progression of arthritis in this model, mice were treated with neutralizing antibodies after the onset of arthritis.ResultsCompared with WT mice, IL‐1Ra−/−mice had similar levels of Th1 cells but clearly enhanced levels of Th17 cells; this increase in the number of Th17 cells was evident even before the onset of arthritis, in young, nonarthritic IL‐1Ra−/−mice. The percentage of Th17 cells increased even more after the onset of arthritis and, similar to the serum levels and local messenger RNA levels of IL‐17, the percentage of IL‐17+ Th17 cells clearly correlated with the severity of arthritis. Anti–IL‐17 treatment prevented any further increase in inflammation and bone erosion, whereas blocking of TNFα after the onset of arthritis had no effect. In contrast, neutralization of IL‐1 resulted in a complete suppression of arthritis. Interestingly, this anti–IL‐1 treatment also significantly reduced the percentage of IL‐17+ Th17 cells in the draining lymph nodes of these arthritic mice.ConclusionIncreased levels of Th17 cells can be detected in IL‐1Ra−/−mice even preceding the onset of arthritis. In addition, the results of cytokine‐blocking studies demonstrated that IL‐17 contributes to the inflammation and bone erosion in this model, which suggests that IL‐1 is the driving force behind the IL‐17–producing Th17 cells.
Predicting the course of juvenile dermatomyositis: Significance of early clinical and laboratory features
Authors: Stringer Elizabeth , Singh‐Grewal Davinder , Feldman Brian M. 
Published: October 2008

AbstractObjectiveJuvenile dermatomyositis (DM) is a rare chronic inflammatory disease of childhood. The clinical course of juvenile DM appears to be variable, and little is known about predictors of the disease course. The aims of this study were to describe the clinical course of juvenile DM and to determine whether early clinical and laboratory features can be used to predict the time to remission and/or the disease course.MethodsClinical and laboratory data from a cohort of 84 patients with juvenile DM were prospectively entered into a database (1990–2005). Remission was defined as a clinical state of no active skin rash, weakness, or elevated muscle enzyme levels for 6 months off medication. The disease course was defined as monophasic, polyphasic, or chronic. Data were reviewed at the time of diagnosis and at 3 months and 6 months after the diagnosis to determine predictors of the time to remission and/or the disease course.ResultsThe median time to remission was 4.67 years. Sixty percent of patients had a chronic course, 37% a monophasic course, and 3% a polyphasic course. The presence of rash (most strongly indicated by Gottron's papules) at 3 months was the earliest predictor of a longer time to remission (relative risk [RR] 0.55 [95% confidence interval (95% CI) 0.37–0.81], P = 0.002). At 6 months, the presence of nailfold abnormalities and rash also predicted a longer time to remission (RR 0.35 [95% CI 0.14–0.74], P = 0.003). We were unable to determine a prediction model of disease course.ConclusionThe majority of patients in our cohort had a chronic disease course. The persistence of Gottron's papules and nailfold abnormalities early in the disease course was associated with a longer time to remission.
Gene expression in systemic lupus erythematosus: Bone marrow analysis differentiates active from inactive disease and reveals apoptosis and granulopoiesis signatures
Authors: Nakou Magdalene , Knowlton Nicholas , Frank Mark B. , Bertsias George , Osban Jeanette , Sandel Clayton E. , Papadaki Helen , Raptopoulou Amalia , Sidiropoulos Prodromos , Kritikos Iraklis , Tassiulas Ioannis , Centola Michael , Boumpas Dimitrios T. 
Published: October 2008

AbstractObjectiveThe cells of the immune system originate from the bone marrow, where many of them also mature. This study was undertaken to examine gene expression in the bone marrow of patients with systemic lupus erythematosus (SLE), in order to better understand the aberrant immune response in this disease.MethodsBone marrow mononuclear cells (BMMCs) from 20 SLE patients (11 with active disease and 9 with inactive disease) and peripheral blood mononuclear cells (PBMCs) from 27 patients (16 with active disease and 11 with inactive disease) were studied; BMMCs and PBMCs from 7 healthy individuals and 3 osteoarthritis patients were studied as controls. Samples were analyzed on genome‐scale DNA microarrays, with 21,329 genes represented.ResultsWe identified 102 genes involved in various biologic processes that were differentially expressed between patient and control BMMCs; 53 of them are genes that are involved in major networks, including cell death, growth, signaling, and proliferation. Comparative analysis revealed 88 genes that were differentially expressed between bone marrow and blood, the majority of which are involved in cell growth and differentiation, cellular movement and morphology, immune response, and other hematopoietic cell functions. Unsupervised clustering of highly expressed genes revealed 2 major SLE patient clusters (active disease and inactive disease) based on gene expression in bone marrow, but not in peripheral blood. The up‐regulated genes in the bone marrow of patients with active disease included genes involved in cell death and granulopoiesis.ConclusionMicroarray analysis of the bone marrow differentiated active from inactive SLE and provided further evidence of the role of apoptosis and granulocytes in the pathogenesis of the disease.
Efficacy and safety of golimumab in patients with ankylosing spondylitis: Results of a randomized, double‐blind, placebo‐controlled, phase III trial
Authors: Inman Robert D. , Davis John C. , Heijde Désirée Van Der , Diekman Laura , Sieper Joachim , Kim Sung Il , Mack Michael , Han John , Visvanathan Sudha , Xu Zhenhua , Hsu Benjamin , Beutler Anna , Braun Jürgen 
Published: October 2008

AbstractObjectiveTo evaluate the efficacy and safety of golimumab in patients with ankylosing spondylitis (AS) in the GO‐RAISE study.MethodsPatients with active AS, a Bath AS Disease Activity Index (BASDAI) score ≥4, and a back pain score of ≥4 were randomly assigned in a 1.8:1.8:1 ratio to receive subcutaneous injections of golimumab (50 mg or 100 mg) or placebo every 4 weeks. The primary end point was the proportion of patients with at least 20% improvement in the ASsessment in AS (ASAS20) criteria at week 14.ResultsAt randomization, 138, 140, and 78 patients were assigned to the 50‐mg, 100‐mg, and placebo groups, respectively. After 14 weeks, 59.4%, 60.0%, and 21.8% of patients, respectively, were ASAS20 responders (P < 0.001). A 40% improvement in the ASAS criteria at week 24 occurred in 43.5%, 54.3%, and 15.4% of patients, respectively. Patients receiving golimumab also showed significant improvement in the physical and mental component summary scores of the Short Form 36 Health Survey, the Jenkins Sleep Evaluation Questionnaire score, the BASDAI score, and the Bath AS Functional Index score, but not the Bath AS Metrology Index score. Through week 24, 85.6% of golimumab‐treated patients and 76.6% of patients in the placebo group had ≥1 adverse event, and 5.4% and 6.5% of patients, respectively, had ≥1 serious adverse event. Eight golimumab‐treated patients and 1 placebo‐treated patient had markedly abnormal liver enzyme values (≥100% increase from baseline and a value >150 IU/liter), which were transient.ConclusionGolimumab was effective and well tolerated in a large cohort of patients with AS during a 24‐week study period.
Novel detection of in vivo HLA–B27 conformations correlates with ankylosing spondylitis association
Authors: Fussell Helen , Nesbeth Darren , Lenart Izabela , Campbell Elaine C. , Lynch Sarah , Santos Susana , Gould Keith , Powis Simon J. , Antoniou Antony N. 
Published: October 2008

AbstractObjectiveThe class I major histocompatibility complex (MHC) molecule HLA–B27 exhibits a strong association with the autoimmune inflammatory arthritis disorder ankylosing spondylitis (AS) and with other related spondylarthropathies. In the absence of both a defined autoimmune response and a target autoantigen(s), the propensity of HLA–B27 to misfold has been hypothesized to be a major parameter in disease pathogenesis. We undertook this study to test the hypothesis that HLA–B27 misfolding is due to exposure of cysteine residues within the heavy chain to the oxidizing environment of the endoplasmic reticulum.MethodsA rapid acidification and alkylation modification method was used to examine cysteine residue exposure and accessibility within AS‐associated and non‐AS–associated HLA–B27 subtypes.ResultsThis novel approach to probing in vivo class I MHC structure revealed that the HLA–B27 heavy chain adopts conformations not previously described. Furthermore, amino acid residues specific to subtypes HLA–B*2706, B*2709, and B*2704 can have an impact on these novel conformations and on cysteine residue exposure.ConclusionHLA–B27 can adopt novel conformations, resulting in differential accessibility of cysteine residues, which can explain the propensity to misfold. Cysteine exposure in the HLA–B27 heavy chain is also affected by residues within the 114 and 116 regions, thereby providing a potential biochemical basis for the association of HLA–B27 subtypes with AS.
CD19 regulates the development of bleomycin‐induced pulmonary fibrosis in a mouse model
Authors: Komura Kazuhiro , Yanaba Koichi , Horikawa Mayuka , Ogawa Fumihide , Fujimoto Manabu , Tedder Thomas F. , Sato Shinichi 
Published: October 2008

AbstractObjectiveThe contribution of CD19 and B lymphocytes to pulmonary fibrosis is controversial. The aim of this study was to address the role of CD19 during the development of pulmonary fibrosis.MethodsMice lacking or overexpressing the B cell surface molecule CD19, which is known as a positive regulator of B cell activation, were used in a model of bleomycin‐induced pulmonary fibrosis. Ten or sixteen days after intratracheal injection of bleomycin, lung sections from mice were evaluated by histologic analysis. Seven days after instillation, the total leukocyte count and the number of B cells in bronchoalveolar lavage fluid (BALF) were determined, using a hemocytometer and flow cytometry. Bleomycin was also administered into selectin‐deficient or intercellular adhesion molecule 1–deficient mouse strains. The level of CXCR3 expression on B cells was determined by flow cytometry.ResultsCD19 deficiency significantly reduced susceptibility to intratracheal bleomycin challenge on day 16, while CD19 overexpression augmented fibrosis even on day 10. Furthermore, the survival rate and number of B cells in BALF also correlated with CD19 expression levels. The accumulation of B cells in BALF was dependent on CD19 levels, whereas there was no association with the levels of selectins or intercellular adhesion molecule 1. Additionally, CXCR3 was up‐regulated in BALF B cells, while it was rarely expressed on circulating B cells. Furthermore, CD19 signaling facilitated B cell CXCR3 up‐regulation in response to stimulation in vitro.ConclusionThese results suggest that CD19 signaling is associated with the development of pulmonary fibrosis by controlling B cell infiltration into lung tissue, which may be associated with CXCR3 up‐regulation.
Patterns of femorotibial cartilage loss in knees with neutral, varus, and valgus alignment
Authors: Eckstein Felix , Wirth Wolfgang , Hudelmaier Martin , Stein Verena , Lengfelder Verena , Cahue September , Marshall Meredith , Prasad Pottumarthi , Sharma Leena 
Published: October 2008

AbstractObjectiveMalalignment is known to alter medial‐to‐lateral femorotibial load distribution and to affect osteoarthritis (OA) progression in the mechanically stressed compartment. We investigated the pattern of cartilage loss in neutral, varus, and valgus knees.MethodsAlignment was measured from full‐limb radiographs in 174 participants with symptomatic knee OA. Coronal magnetic resonance images were acquired at baseline and a mean ± SD of 26.6 ± 5.4 months later. The weight‐bearing femorotibial cartilages were segmented from paired images. Cartilage volume, surface area, and thickness were determined in total cartilage plates and defined subregions using proprietary software.ResultsThe medial‐to‐lateral ratio of femorotibial cartilage loss was 1.4:1 in neutral knees (n = 74), 3.7:1 in varus knees (n = 57), and 1:6.0 in valgus knees (n = 43). The relative contribution of cartilage thickness change tended to be greater in knees with mild cartilage loss, whereas the increase of denuded area was greater in knees with accelerated cartilage loss. In both varus and neutral knees, the greatest changes were observed in the same subregions of the medial femorotibial compartment (central and external medial tibia, and central medial femur). In valgus and neutral knees, the subregions with the greatest changes in the lateral femorotibial compartment were also similar (internal and central lateral tibia, external lateral femur).ConclusionThe medial‐to‐lateral rate of femorotibial cartilage loss strongly depended on alignment. Subregions of greater‐than‐average cartilage loss within the stressed compartment were, however, similar in neutral, varus, and valgus knees. This indicates that the medial‐to‐lateral loading pattern is different, but that the (sub)regional loading pattern may not differ substantially between neutral and malaligned knees.