bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth and aggregation of vaterite in seeded‐batch experiments
Authors: Andreassen Jens‐P. , Hounslow M. J. 
Published: October 2004

AbstractSeeded‐batch crystallization experiments allowing study of the growth and aggregation of the Vaterite modification of calcium carbonate are reported. Results are reported for initial relative supersaturation (σ = S − 1) values in the range 1.66 to 6.70, stirrer speeds in the range 400 and 1200 rpm, and at temperatures of 25 and 40°C. It is found that in all cases the linear rate of growth of the particles is size independent and depends on relative supersaturation squared. The aggregation process is apparently size independent with a rate constant that is directly proportional to the instantaneous growth rate and decreases with increasing stirrer speed. The behavior of the aggregation rate constant is very well described by the model recently proposed by Liew et al., in which the efficiency of the aggregation process is predicted to depend only on the dimensionless strength of the particles and the nature of the flow field. It is concluded that Vaterite forms aggregates with crystalline bridges having an effective strength of approximately 25% of that of calcite or calcium oxalate monohydrate. The fitted parameter Lσ*/M50 takes on a value of 0.18 ± 0.02. The kinetics and associated model are capable of describing the evolving particle size distributions very well. Finally, a hypothesis is advanced to describe the aggregation of small inorganic crystals in supersaturated solutions. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2772–2782, 2004
Methane steam reforming by microporous catalytic membrane reactors
Authors: Tsuru Toshinori , Yamaguchi Koji , Yoshioka Tomohisa , Asaeda Masashi 
Published: October 2004

AbstractMethane steam reforming, with and without added oxygen, was theoretically and experimentally investigated using microporous silica membranes, thus allowing the permeation of hydrogen as well as other gases in reactants and products. A simulation of catalytic membrane reactors was carried out for a cocurrent, isothermal, and plug‐flow–type membrane reactor with the selective permeation of hydrogen through microporous membranes. The effect of operating conditions on the conversion of methane and hydrogen production is discussed with the aid of two dimensionless numbers, the Damköhler number (Da) and the permeation number (θ). Methane conversion, XCH4, has approximately the same dependency on permeation number in terms of the permeability ratios of hydrogen over nitrogen, whereas the purity of hydrogen in the permeate increased with increasing hydrogen selectivity. Catalytic membrane reactors, consisting of a silica microporous layer and a Ni‐catalyst layer, were prepared. The permeability ratio of hydrogen over steam, α(H2/H2O), which ranged from 1 to 20, showed a relatively good correlation with that for helium over hydrogen, α(He/H2). Catalytic membrane reactors showing a hydrogen selectivity over nitrogen of 30–100, with hydrogen permeances of 0.5–3 × 10−7 mol m−2 s−1 Pa−1, were applied to the steam reforming of methane with and without the addition of oxygen. The reaction was carried out at 500°C, and the feed and permeate pressure were maintained at 100 and 20 kPa, respectively. Methane conversion, XCH4, increased up to approximately 0.8 beyond the equilibrium conversion of 0.44 by extracting hydrogen in permeate stream. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2794–2805, 2004
High resolution algorithms for multidimensional population balance equations
Authors: Gunawan Rudiyanto , Fusman Irene , Braatz Richard D. 
Published: October 2004

AbstractPopulation balance equations have been used to model a wide range of processes including polymerization, crystallization, cloud formation, and cell dynamics. Rather than developing new algorithms specific to population balance equations, it is proposed to adapt the high‐resolution finite volume methods developed for compressible gas dynamics, which have been applied to aerodynamics, astrophysics, detonation waves, and related fields where shock waves occur. High‐resolution algorithms are presented for simulating multidimensional population balance equations with nucleation and size‐dependent growth rates. For sharp distributions, these high‐resolution algorithms can achieve improved numerical accuracy with orders‐of‐magnitude lower computational cost than other finite difference and finite volume algorithms. The algorithms are implemented in the ParticleSolver software package, which is applied to batch and continuous processes with one and multiple internal coordinates. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2738–2749, 2004
Modeling for size reduction of agglomerates in nanoparticle fluidization
Authors: Matsuda Satoru , Hatano Hiroyuki , Muramoto Tomoya , Tsutsumi Atsushi 
Published: October 2004

AbstractNanoparticle fluidization was studied in a centrifugal fluidized bed (CenFB) with variable gravitational acceleration (Gg) conditions. Agglomerate size variation in CenFB nanoparticles (7 nm) was examined with G and fluidization time. With increasing fluidization time, the agglomerate size was found to decrease and reach an equilibrium value after several hours. Higher G reduced agglomerate size. To elucidate these phenomena, a comprehensive model was developed based on the energy balance model with respect to energy consumption for disintegration of agglomerates. Experimental results showed good agreement with the proposed model. Effects of high G on agglomerate fluidization are clarified as follows. The critical minimum size of agglomerates, which is the agglomerate size estimated by the force balance model, is reduced by high G. Attainable energy for disintegration of agglomerates is increased, leading to decreased agglomerate size. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2763–2771, 2004
Prediction of rolling bed motion in rotating cylinders
Authors: Mellmann Jochen , Specht Eckehard , Liu Xiaoyan 
Published: October 2004

AbstractA mathematical model for the range of rolling bed motion has been developed to calculate the transverse solids motion in rotating cylinders. It is based on mass and momentum balances with physically specified and hence known initial conditions. The behavior of the bed material need only be described by two measurable parameters, the dynamic angle of repose and the angle of slope at the start of the boundary line (interface between the cascading layer and the plug flow region). The shape of the boundary line, the thickness of the cascading layer, the mass flow rate, and the velocity at the surface can be predicted as a function of rotation speed, filling degree, and cylinder diameter. No fitting parameter is needed for the calculation. To verify the model, experiments were carried out for many bed materials and rotating cylinder conditions. A correlation for the angle of slope at the start of the boundary line is given. The calculated results of the model are then compared to our own measurements and those reported in the literature. It is shown that the model agrees relatively well with the experiments. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2783–2793, 2004
Association between spine disc degeneration and type II collagen degradation in postmenopausal women: The OFELY study
Authors: Garnero Patrick , Sornay‐Rendu Elisabeth , Arlot Monique , Christiansen Claus , Delmas Pierre D. 
Published: October 2004

AbstractObjectiveTo investigate whether radiologic spine disc degeneration is associated with increased type II collagen (CII) degradation products in the urine of postmenopausal women, independently of radiologic knee osteoarthritis (OA) and clinical hand OA.MethodsThe study group comprised 324 postmenopausal women ages 58–94 years who had no treatment or disease that could alter bone metabolism. Lateral radiographs of the thoracic and lumbar spine were obtained in each woman and scored for disc space narrowing (DSN) and osteophytes. Fixed‐flexion posteroanterior radiographs of the knee were obtained to assess femorotibial knee OA. In all women, hand OA was assessed by clinical examination, and the level of urinary C‐terminal crosslinking telopeptide of CII (CTX‐II), a biologic marker of CII degradation, was measured.ResultsThe prevalences of radiographic lumbar and thoracic spine disc degeneration, knee OA, and clinical hand OA were 84%, 88%, 35%, and 58%, respectively. After adjustment for age and body mass index (BMI), patients with lumbar spine DSN grade ≥1 had, on average, 34% higher CTX‐II levels compared with the other women (P = 0.0005), whereas no association was observed with lumbar spine osteophytes. No significant association between thoracic spine DSN or osteophytes and urinary CTX‐II levels was observed. Multivariate analysis of variance showed that, after adjustment for age and BMI, lumbar spine DSN (P = 0.0049), knee OA (P = 0.0055), and clinical hand OA (P = 0.0060) were, independently of each other, associated with CTX‐II levels. Thus, patients with lumbar spine DSN, knee OA, and clinical hand OA had CTX‐II levels 80% higher (P < 0.0001 after adjustment for age and BMI) than those of patients with no lumbar spine DSN, no radiologic knee OA, and no clinical hand OA.ConclusionPostmenopausal women with lumbar spine disc degeneration are characterized by increased CII degradation. The contribution of lumbar spine DSN to CII degradation was similar to, and independent of, the contribution of radiologic knee OA or clinical hand OA. Lumbar spine disc degeneration in elderly patients should be assessed when analyzing levels of CTX‐II in studies of knee, hip, and hand OA.
Work above shoulder level and degenerative alterations of the rotator cuff tendons: A magnetic resonance imaging study
Authors: Svendsen Susanne Wulff , Gelineck John , Mathiassen Svend Erik , Bonde Jens Peter , Frich Lars Henrik , Stengaard‐Pedersen Kristian , Egund Niels 
Published: October 2004

AbstractObjectiveTo determine whether work performed with the arms in a highly elevated position is associated with alterations in the rotator cuff tendons as assessed by magnetic resonance imaging (MRI).MethodsA cross‐sectional study was performed in a historical cohort of male machinists, car mechanics, and house painters. The participants were right‐handed, ages 40–50 years, and had been employed in their trades for not less than 10 years. Seventy‐one percent of invited subjects participated (136 of 192). Lifetime upper arm elevation was assessed by direct measurements combined with individual work histories obtained by questionnaire and from registry data. Supraspinatus tendinopathy was evidenced by MRI signal intensity changes and morphologic alterations. Infraspinatus and subscapularis tendinopathy were also assessed. Additional outcomes were acromioclavicular joint degeneration and humeral head cysts. The MRI findings were evaluated by radiologists who were blinded to exposure status and symptoms.ResultsAn exposure–response relationship was found between lifetime upper arm elevation and supraspinatus tendinopathy, with an age‐adjusted odds ratio of 1.27 (95% confidence interval 1.02–1.60) for a 5‐month increase in the total number of full‐time working months spent with the arm elevated >90°.ConclusionWork with the arms in a highly elevated position is associated with MRI‐diagnosed alterations in the supraspinatus tendon. By demonstrating the first part of a possible biologic pathway, the study corroborates the work‐relatedness of rotator cuff disorders.
Characterization of pristane‐induced arthritis, a murine model of chronic disease: Response to antirheumatic agents, expression of joint cytokines, and immunopathology
Authors: Patten Christopher , Bush Katherine , Rioja Inma , Morgan Rebecca , Wooley Paul , Trill John , Life Paul 
Published: October 2004

AbstractObjectiveTo characterize chronic murine pristane‐induced arthritis (PIA) with regard to the response to antirheumatic agents, expression levels of proinflammatory cytokines, and immunopathologic features.MethodsMale DBA/1 mice were injected intraperitoneally with pristane oil to induce a chronic polyarthritis, which was monitored by visual scoring. Serum antibody and splenocyte responses to a panel of putative joint‐derived autoantigens were measured. Whole paws were evaluated postmortem for changes in the levels of proinflammatory cytokines tumor necrosis factor α (TNFα), interleukin‐1β (IL‐1β), and IL‐6 by enzyme‐linked immunosorbent assay, and standard histopathology techniques were used to determine joint structural changes. Therapeutic studies were performed for up to 8 weeks of dosing with prednisolone, methotrexate, 3 nonsteroidal antiinflammatory drugs (celecoxib, diclofenac, and indomethacin), a p38 MAPK inhibitor, SB242235, and human soluble TNF receptor (sTNFR; etanercept) and murine sTNFR fusion proteins.ResultsAntibody and cellular responses to the putative joint autoantigens revealed a broad extent of autoimmunity in PIA. TNFα, IL‐1β, and IL‐6 were all persistently up‐regulated in PIA joints. Prednisolone, methotrexate, celecoxib, indomethacin, and SB242235 all significantly reduced the arthritis scores. Etanercept was ineffective in reducing the arthritis scores, whereas murine sTNFR produced a significant, but nonsustained, benefit. Only prednisolone significantly reduced the expression of TNFα, IL‐1β, and IL‐6 in the joints. Prednisolone and methotrexate demonstrated the most effective joint protection.ConclusionWe have markedly extended the characterization of PIA as a murine model of chronic inflammatory arthritis by demonstrating cellular and humoral autoantigenicity, elevation of clinically precedented joint cytokines, and variation in the response to several antirheumatic therapies. PIA offers significant potential for the long‐term study of immunopathologic mechanisms and novel therapies in rheumatoid arthritis.
Multisequence magnetic resonance imaging study of neuropsychiatric systemic lupus erythematosus
Authors: Bosma G. P. Th. , Steens S. C. A. , Petropoulos Helen , Admiraal‐Behloul Faiza , van den Haak A. , Doornbos J. , Huizinga T. W. J. , Brooks William M. , Harville Aaron , Sibbitt Wilmer L. , van Buchem M. A. 
Published: October 2004

AbstractObjectiveTo investigate the relationship between magnetization transfer imaging (MTI), diffusion‐weighted imaging (DWI), proton magnetic resonance spectroscopy (H‐MRS), and T2 relaxometry findings in patients with primary neuropsychiatric systemic lupus erythematosus (NPSLE).MethodsThe study group consisted of 24 female patients (mean age 36 years [range 23–65]) who had had a variety of neuropsychiatric symptoms that were judged to be due to NPSLE according to the criteria of the American College of Rheumatology. Patients with current active disease were excluded from participation. Quantitative MTI, DWI, H‐MRS, and T2 relaxometry data were acquired in all patients, and the correlation coefficients were calculated.ResultsMTI results reflecting a decrease in homogeneity of cerebral parenchyma correlated significantly with H‐MRS results representing axonal damage. MTI results also correlated significantly with DWI results reflecting increased diffusivity in the cerebral parenchyma. Finally, MTI results reflecting decreased cerebral homogeneity correlated significantly with increased T2 relaxation time, associated with either edema or gliosis. Increased T2 relaxation time correlated significantly with DWI results reflecting increased diffusivity. With the exception of the correlation between H‐MRS and MTI findings, there was no significant correlation between H‐MRS results and any other parameter.ConclusionThe selected study parameters represent different biologic features in the human brain and can be informative with regard to different pathologic processes in NPSLE. The demonstrated associations between MTI, DWI, H‐MRS, and T2 data in patients with a history of NPSLE suggest that there is one pathogenesis and/or common neuropathologic outcome in NPSLE despite differences in clinical presentation.
Antigen‐specific immunomodulation of collagen‐induced arthritis with tumor necrosis factor–stimulated dendritic cells
Authors: van Duivenvoorde Leonie M. , Louis‐Plence Pascale , Apparailly Florence , van der Voort Ellen I. H. , Huizinga Tom W. J. , Jorgensen Christian , Toes René E. M. 
Published: October 2004

AbstractObjectiveDendritic cells (DCs) are crucial for the initiation of T cell immunity and therefore play an important role in the initiation and regulation of immune responses in arthritis. Full mobilization of effector T cells depends on the proper maturation of DCs. Current evidence indicates that the type of T cell response induced is crucially dependent on the activation status of the DCs. In this study, we explored the immunologic effects of differentially matured DCs on the development of collagen‐induced arthritis (CIA).MethodsBone marrow–derived DCs were cultured in the presence of granulocyte–macrophage colony‐stimulating factor (GM‐CSF). Before immunization with bovine type II collagen (CII) protein, mice were repeatedly injected with DCs that had been pulsed with CII. Immature, semimature, or fully mature DCs were injected. Mice were boosted on day 21 after CII immunization, and the disease course was monitored.ResultsWhile vaccination with immature or lipopolysaccharide‐activated DCs had no significant effect on the disease course, administration of antigen‐loaded, tumor necrosis factor (TNF)–modulated DCs propagated in GM‐CSF with or without interleukin‐4 resulted in a delayed onset of arthritis and a lower clinical score. The response was antigen‐specific, since TNF‐treated DCs pulsed with a control antigen did not modify the disease course. A specific decrease in the collagen‐specific “Th1‐associated” IgG2a response was observed, whereas IgG1 titers were unaffected.ConclusionCIA can be prevented through vaccination with TNF‐matured DCs in an antigen‐specific manner. These findings provide a rationale for immunotherapy using DCs in rheumatoid arthritis.
Direct binding of anti–DNA topoisomerase I autoantibodies to the cell surface of fibroblasts in patients with systemic sclerosis
Authors: Hénault Jill , Tremblay Mélanie , Clément Isabelle , Raymond Yves , Senécal Jean‐Luc 
Published: October 2004

AbstractObjectiveFibroblasts play a crucial role in the development of systemic sclerosis (SSc), and antifibroblast antibodies (AFAs) capable of inducing a proinflammatory phenotype in fibroblasts have been detected in the sera of SSc patients. This study examined the prevalence of AFAs in SSc and other diseases and the possible correlation between AFAs and known antinuclear antibody specificities in SSc patients.MethodsSera from 99 patients with SSc, 123 patients with other autoimmune and nonautoimmune diseases, and 30 age‐ and sex‐matched healthy controls were examined. AFA prevalence was assessed by flow cytometry and further characterized by indirect immunofluorescence, enzyme‐linked immunosorbent assay (ELISA), and immunoblotting. Anti–topoisomerase I (anti–topo I) from SSc sera were purified by affinity chromatography on topo I.ResultsAFAs were more common in SSc patients (26.3%) than in any other disease groups studied. The presence of AFA was significantly associated with pulmonary involvement and death. AFA‐positive sera from SSc patients bound to all human and rodent fibroblasts tested, but not to human primary endothelial cells or smooth muscle cells. All SSc AFAs strongly reacted with topo I by ELISA and immunoblotting. The binding intensity of SSc AFAs correlated strongly with reactivity against topo I on immunoblots of fibroblast extracts and with the immunofluorescence pattern typical of anti–topo I on permeabilized cells. Total IgG and affinity‐purified anti–topo I from AFA‐positive SSc sera were found to react with the surface of unpermeabilized fibroblasts by flow cytometry as well as by immunofluorescence and confocal microscopy.ConclusionThis is the first report establishing that AFAs in SSc are strongly correlated with anti–topo I and, furthermore, that anti–topo I antibodies themselves display AFA activity by reacting with determinants at the fibroblast surface.
Treatment of murine lupus using nucleosomal T cell epitopes identified by bone marrow–derived dendritic cells
Authors: Suen Jau‐Ling , Chuang Ya‐Hui , Tsai Bor‐Yu , Yau Peter M. , Chiang Bor‐Luen 
Published: October 2004

AbstractObjectiveSystemic lupus erythematosus (SLE) is characterized by the existence of a heterogeneous group of autoantibodies directed against intact nuclear structures, such as nucleosomes. The most prominent of these autoantibodies are those directed against double‐stranded DNA (dsDNA) and histones. The majority are of the IgG isotype and show affinity maturation, both of which are known hallmarks of T cell help. Much evidence suggests that the nucleosome is a major candidate autoantigen in SLE. In this study, a novel strategy was used to identify the critical CD4+ T cell autoepitopes in nucleosomes. In addition, peptide‐based therapy was then performed in a lupus animal model.MethodsBone marrow (BM)–derived dendritic cells (DCs) were used to examine the self–T cell responses against nucleosomes and to characterize the T cell epitope(s) of nucleosomes in (NZB × NZW)F1 (BWF1) mice.ResultsSeveral potential auto–T cell epitopes of core histone proteins (H2A, H2B, H3, and H4) were identified. Nucleosome‐pulsed BM‐derived DCs elicited release of interleukin‐4 and interferon‐γ, representing a Th0 (i.e., mixed Th1 and Th2) pattern of cytokine production. In addition, intradermal immunization of BWF1 mice with the H3111–130 peptide not only suppressed the level of anti‐dsDNA and anti–single‐stranded DNA IgG, but also significantly delayed the progress of glomerulonephritis in lupus‐prone BWF1 mice.ConclusionThese results will help in understanding how pathogenic autoimmune responses develop in spontaneous SLE. This may potentially open the way to T cell–based immunotherapy for lupus.
Development and validation of the health assessment questionnaire II: A revised version of the health assessment questionnaire
Authors: Wolfe Frederick , Michaud Kaleb , Pincus Theodore 
Published: October 2004

AbstractObjectiveThe Health Assessment Questionnaire (HAQ) has become the most common tool for measuring functional status in rheumatology. However, the HAQ is long (34 questions, including 20 concerning activities of daily living and 14 relating to the use of aids and devices) and somewhat burdensome to score, has some floor effects, and has psychometric problems relating to linearity and confusing items. We undertook this study to develop and validate a revised version of the HAQ (the HAQ‐II).MethodsUsing Rasch analysis and a 31‐question item bank, including 20 HAQ items, the 10‐item HAQ‐II was developed. Five original items from the HAQ were retained. We studied the HAQ‐II in 14,038 patients with rheumatic disease over a 2‐year period to determine its validity and reliability.ResultsThe HAQ‐II was reliable (reliability of 0.88, compared with 0.83 for the HAQ), measured disability over a longer scale than the HAQ, and had no nonfitting items and no gaps. Compared with the HAQ, modified HAQ, and Medical Outcomes Study Short Form 36 physical function scale, the HAQ‐II was as well correlated or better correlated with clinical and outcome variables. The HAQ‐II performed as well as the HAQ in a clinical trial and in prediction of mortality and work disability. The mean difference between the HAQ and HAQ‐II scores was 0.02 units.ConclusionThe HAQ‐II is a reliable and valid 10‐item questionnaire that performs at least as well as the HAQ and is simpler to administer and score. Conversion from HAQ to HAQ‐II and from HAQ‐II to HAQ for research purposes is simple and reliable. The HAQ‐II can be used in all places where the HAQ is now used, and it may prove to be easier to use in the clinic.