bluuebunny/crossref_metadata_2025_split huggingface dataset:
Superplastic failure mode in ultrafine grained magnesium alloy AZ31
Authors: Lapovok Rimma , Williams Tim , Estrin Yuri 
Published: April 2009

Abstract
The paper addresses the failure mode of ultrafine grained magnesium alloy AZ31 under superplastic deformation conditions. The ultrafine grain structure and the resulting exceptional superplastic properties were produced by Equal Channel Angular Pressing with an imposed hydrostatic pressure conducted at a relatively low temperature of 150 °C. The mechanism of the superplastic ductility was studied by examining the fracture surfaces and internal cavities in superplastically deformed specimens by scanning electron microscopy. The presence of Mg17Al12 particles was identified as the controlling microstructural feature giving rise to porosity formation and limiting tensile ductility. Fine details of the failure process depending on the particle and precipitate structure as well as textural effects were described.
A model of grain boundary diffusion in polycrystals with evolving microstructure
Authors: Klinger Leonid , Rabkin Eugen 
Published: April 2009

Abstract
We consider grain boundary diffusion in a polycrystal in which normal grain growth occurs simultaneously with diffusion. We assume that any point within the diffusion zone is swept a number of times by migrating grain boundaries, and develop a model which operates with the average concentrations of the diffusant in the planes parallel to diffusion front. We derive analytical expressions describing the diffusion profiles both for constant source and instantaneous source boundary conditions. Finally, we suggest a practical method for extracting the grain boundary diffusion coefficient from experimentally measured diffusion profiles. This method relies on microstructure characterization and requires the grain growth constant and grain growth exponent to be determined in the independent set of experiments.
Comparison of texture evolution in fcc metals predicted by various grain cluster homogenization schemes
Authors: Eisenlohr Philip , Tjahjanto Denny D. , Hochrainer Thomas , Roters Franz , Raabe Dierk 
Published: April 2009

Abstract
We introduce a new material point homogenization scheme – the ‘Relaxed Grain Cluster’ (RGC) – based on a cluster of grains and formulated in the framework of finite deformations. Two variants of this scheme, which allow for different degrees of relaxation, are compared to two variants derived from the infinitesimal-strain grain interaction model regarding the evolution of texture predicted for plane-strain compression of a commercial aluminum alloy. The RGC schemes give the closest match to experimental reference on both the -fiber and the -skeleton line. The intensity of the brass texture component is found to be rather sensitive to the homogenization scheme. However, the observed decrease in texture intensity as a function of the homogenization scheme for the Cu and S component on the -skeleton line can be correlated to the number of degrees of freedom in the cluster which are left unconstrained by the respective scheme. This is in line with the significant dependence of the Cu and S component intensity on boundary conditions reported in earlier studies.
Nanoindentation of Ti50Ni48Fe2 and Ti50Ni40Cu10 shape memory alloys
Authors: Zheng Hongxing , Pfetzing Janine , Frenzel Jan , Eggeler Gunther 
Published: April 2009

Abstract
In the present paper we use nanoindentation to investigate two shape memory alloys, austenitic Ti50Ni48Fe2 and martensitic Ti50Ni40Cu10 which both show two step martensitic transformations on cooling from the high temperature regime. No such two step features were observed during nanoindentation. Load controlled nanoindentation experiments were performed using a Berkovich indenter using maximum loads ranging from 0.5 to 85 mN resulting in maximum indentation depths between 30 and 1350 nm. For small maximum indentation loads below 5 mN, longer indentation times result in larger indentation depths (austenitic Ti50Ni48Fe2). At loads of about 1 mN the indentation curves show an abrupt change in slope which we suggest to be related to an interaction of the deformation and failure of a thin oxide layer and the formation of stress induced martensite (austenitic Ti50Ni48Fe2) or the de-twinning of martensite (martensitic Ti50Ni40Cu10). Nanohardnesses and shape recovery ratios strongly increase with decreasing indentation depths below 400 nm. For larger indentation depths, constant values are observed (austenitic Ti50Ni48Fe2: nanohardness 2.45 GPa/recovery ratio 0.25, martensitic Ti50Ni40Cu10: nanohardness 1.6 GPa/recovery ratio 0.4).
Testing a curvature driven moving finite element grain growth model with the generalized three dimensional von Neumann relation
Authors: Uyar Fatma , Wilson Seth R. , Gruber Jason , Lee Sukbin , Sintay Stephen , Rollett Anthony D. , Srolovitz David J. 
Published: April 2009

Abstract
The von Neumann – Mullins relation has been extended to higher dimensions by MacPherson and Srolovitz. Their exact solution relates the rate of volume change of an individual grain in a 3-dimensional isotropic polycrystal to its mean width and total length of triple lines (assuming isotropic boundaries). The objective of this study is to verify that grains in a moving finite element grain growth model obey this law. Algorithms have been developed in order to calculate mean width of individual grains in digital microstructures for which the grain structure is discretized with both volumetric and surface meshes. Theoretical rate predictions were obtained from the measured mean widths and triple line lengths. Good agreement was found between growth rates measured in the simulations and the predictions of MacPherson – Srolovitz theory for the cases of an isolated shrinking sphere, individual grains in a digitally generated coarse polycrystal, and individual grains in a microstructure reconstructed from serial sectioning of stabilized cubic zirconia. Departures from this relationship appeared to be related to the grain shape.
Interface Migration in Metals (IMM):“Vingt Ans Après” (Twenty Years Later)
Authors: Molodov D. A. , Shvindlerman L. S. 
Published: April 2009

Abstract
The paper represents a comprehensive although rather brief overview of the scientific activity of the Institute of Physical Metallurgy and Metal Physics (IMM), RWTH Aachen University, in the field of grain boundary physics for the past twenty years under the leadership of Professor Günter Gottstein.
Frequency, Risk, and Cost of Gout-related Episodes Among the Elderly: Does Serum Uric Acid Level Matter?
Authors: WU ERIC Q. , PATEL PANKAJ A. , MODY REEMA R. , YU ANDREW P. , CAHILL KEVIN E. , TANG JACKSON , KRISHNAN ESWAR 
Published: April 2009

Objective.We examined the association between serum uric acid (SUA) level and the frequency, risk, and cost of gout flares among the elderly.Methods.Data were extracted from the Integrated Healthcare Information Services claims database (1999–2005). Patients were included if they had gout, were aged 65 years and older and had both medical and pharmacy benefits, and electronic laboratory data. Patients with gout and gouty episodes were identified using algorithms based on ICD-9-CM codes and medications. Logistic regression and negative binomial regressions were used to study the relationship between SUA concentration and the annual frequency and one-year risk of gout episodes. Generalized linear models were used to examine the direct healthcare costs associated with gout episodes in the 30 days following each episode.Results.Elderly patients with gout (n = 2237) with high (6–8.99 mg/dl) and very high (> 9 mg/dl) SUA concentrations were more likely to develop a flare within 12 months compared to patients with normal (< 6 mg/dl) SUA levels (OR 2.1, 95% CI 1.7–2.6; OR 3.4, 95% CI 2.6–4.4, respectively). In multivariate regressions, the average annual number of flares increased by 11.9% (p < 0.001) with each unit-increase in SUA level above 6 mg/dl (p < 0.001). Among patients with very high SUA levels, average adjusted total healthcare and gout-related costs per episode were $2,555 and $356 higher, respectively, than those of patients with normal SUA levels (both p < 0.001).Conclusion.Higher SUA levels are associated with increased frequency and risk of gout episode, and with higher total and gout-related direct healthcare costs per episode.
Contrast-enhanced Coded Phase-inversion Harmonic Sonography of Knee Synovitis Correlates with Histological Vessel Density: 2 Automated Digital Quantifications
Authors: KAISER MARIE-JOËLLE , HAUZEUR JEAN-PHILIPPE , BLACHER SILVIA , FOIDART JEAN-MICHEL , DEPREZ MANUEL , ROSSKNECHT ALEXANDRA , MALAISE MICHEL G. 
Published: April 2009

Objective.To use contrast-enhanced coded phase-inversion harmonic B-mode sonography to assess the acoustic enhancement of the synovial area of the knee; and to compare the data with the histological vessel density.Methods.Eleven patients eligible for a knee arthroscopy were studied. Acoustic quantification was carried out by a digital image analysis program that detects the time-dependent increase [intensity (time) = k × time + C] of gray-level intensity in all the pixels of a specific region of interest (ROI) following intravenous injection of the microbubble contrast agent sulfur hexafluoride. Echo-guided synovial biopsies were carried out in the same ROI. Synovial vessel areas were quantified after Factor VIII immunostaining of synovial biopsies using an automated digital image analysis.Results.Significant (p < 0.05) correlations were observed between histological vessel density and percentage of the synovial area with a k value > 0.01 (r = 0.93) and kmaxvalues (r = 0.79), as well as between the 2 latter parameters (r = 0.72). The histological vessel density and the 2 acoustic parameters were also significantly correlated with the logarithm of erythrocyte sedimentation rate (r = 0.77, r = 0.87, r = 0.67, respectively) and with log C-reactive protein serum concentration (r = 0.69, r = 0.83, r = 0.62, respectively).Conclusion.Contrast-enhanced coded phase-inversion harmonic B-mode sonography coupled with an appropriate data analysis method is a new tool to identify and quantify vessel density in knee synovitis.
Utilization Trends of Tumor Necrosis Factor Inhibitors Among Patients with Rheumatoid Arthritis in a United States Observational Cohort Study
Authors: LEE SUSAN J. , CHANG HONG , YAZICI YUSUF , GREENBERG JEFFREY D. , KREMER JOEL M. , KAVANAUGH ARTHUR 
Published: April 2009

Objective.Studies have suggested that early institution of tumor necrosis factor (TNF) inhibitors improves functional status and slows radiographic progression among patients with rheumatoid arthritis (RA). To determine whether these findings have altered practice patterns, we used the Consortium of Rheumatology Researchers of North America (CORRONA) registry to assess the pattern of TNF inhibitor utilization in the US over time.Methods.Demographics and disease activity data were collected for patients with RA. The trend of TNF inhibitor use during 2002–06 was evaluated prospectively using linear and logistic regression models.Results.Of the 11,397 patients with RA, 66% and 34% had established RA and early RA (disease duration < 3 yrs), respectively. The majority of patients were female and Caucasian. Despite comparable levels of disease activity, more of the patients with established RA were taking TNF inhibitors than those with early RA (40% vs 25%; p < 0.0001). The majority of patients (70%) taking TNF inhibitors were also receiving disease modifying antirheumatic drugs. The use of TNF inhibitors increased at a rate of 2.8% per year in established RA and 1.2% per year in early RA. The mean Clinical Disease Activity Index at the start of TNF inhibitors decreased at a rate of −0.233 per quarter (p = 0.006), while the mean Disease Activity Score decreased at a rate of −0.04 per quarter (p = 0.022).Conclusion.Utilization of TNF inhibitors in this multicenter, observational US cohort is increasing in both early and established RA, although it is more prominent among patients with established RA. The level of disease activity at which TNF inhibitors were initiated decreased over time in patients with both established and early RA.
Conventional Lipid Profile and Lipoprotein(a) Concentrations in Treated Patients with Rheumatoid Arthritis
Authors: GARCÍA-GÓMEZ CARMEN , NOLLA JOAN M. , VALVERDE JOSEP , GÓMEZ-GERIQUE JUAN A. , CASTRO MARÍA J. , PINTÓ XAVIER 
Published: April 2009

Objective.Patients with rheumatoid arthritis (RA) have an increased cardiovascular risk not completely explained by traditional cardiovascular risk factors. If the proatherogenic lipid profile observed in active and untreated RA improves by effectively treating RA without the use of a lipid-lowering agent, other nonconventional cardiovascular lipid risk factors may be implicated. We evaluated conventional lipid risk factors and lipoprotein(a) in treated patients with RA.Methods.This cross-sectional study was conducted in 122 patients with RA. Lipid profiles of patients were compared with a control group, consisting of a population-based study cohort (DRECE study), matched for sex, age, menopausal status, and body mass index. Excess lipoprotein(a) was defined by a serum concentration > 0.3 g/l.Results.High-density lipoprotein cholesterol (HDL-c) concentrations were higher in pre- and postmenopausal women with RA than in controls (p = 0.023 and p ≤ 0.001, respectively). All RA patients had significantly lower levels of apolipoprotein B and apolipoprotein B/apolipoprotein A-I ratio, and postmenopausal women with RA also had significantly lower low-density lipoprotein cholesterol and total cholesterol levels than their respective controls. No differences were observed in serum levels of apolipoprotein A-I and triglyceride. All RA patients had higher lipoprotein(a) values than controls. Fourteen men (56%) and 10 (53%) and 42 (54%) pre- and postmenopausal women with RA, respectively, had hyperlipoproteinemia(a).Conclusion.RA patients undergoing antirheumatic therapy display a nonatherogenic conventional lipid profile, i.e., high HDL-c, low apolipoprotein B concentrations, and low apolipoprotein B/apolipoprotein A-I ratio. This may be counteracted by the high prevalence of hyperlipoproteinemia(a) observed in these patients.
Serum Urate During Acute Gout
Authors: SCHLESINGER NAOMI , NORQUIST JOSEPHINE M. , WATSON DOUGLAS J. 
Published: April 2009

Objective.To study the frequency of normal serum urate (SU) levels during acute gout in the largest studies of acute gout treatment to date.Methods.Data collected from 2 randomized controlled clinical trials assessing the efficacy of etoricoxib or indomethacin for 7 days in acute gout were used to assess SU levels during acute gouty attacks. Efficacy was similar with both agents, so both groups were combined for analysis.Results.A total of 339 patients were enrolled in the 2 studies; 94% were male; mean age was 50.5 years. At baseline, 14% of patients had a “true” normal SU (≤ 6 mg/dl) and 32% had SU ≤ 8 mg/dl during acute gout. Baseline mean SU was 7.1 versus 8.5 mg/dl (p < 0.001) in those taking allopurinol versus nonusers. Patients taking chronic allopurinol were more likely to have lower SU at baseline compared to those not taking chronic allopurinol (p < 0.001) during the acute attack.Conclusion.A normal SU level at presentation does not exclude an acute gouty attack. In the largest studies of acute gout to date, attacks still occurred despite SU levels being below 6.8 mg/dl, the saturation level for urate. This may be attributed to persistence of tophi and an increased body uric acid pool. Additional studies are needed to determine the correlation between SU and the body uric acid pool as well as the relationship to timing of changes during acute gout.
Delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage: Clinical Associations in Obese Adults
Authors: ANANDACOOMARASAMY ANANTHILA , GIUFFRE BRUNO M. , LEIBMAN STEVEN , CATERSON IAN D. , SMITH GARETT S. , FRANSEN MARLENE , SAMBROOK PHILIP N. , MARCH LYN M. 
Published: April 2009

Objective.Delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) is used to assess cartilage glycosaminoglycan distribution. Our aim was to determine the relationships between self-reported pain and disability, clinical variables, and serum leptin, and dGEMRIC indices in obese subjects with and without clinical knee osteoarthritis (OA).Methods.Seventy-seven subjects were recruited from laparoscopic adjustable gastric banding or exercise and diet-weight loss programs. The dGEMRIC index was assessed on MRI according to established protocol. Regression analysis adjusted for age, sex, body mass index (BMI), and presence of clinical knee OA.Results.Mean age and BMI were 51 ± 12.7 years and 39.6 ± 6.2 kg/m2. Twenty-three subjects (30%) had clinical knee OA (American College of Rheumatology criteria). The medial and lateral dGEMRIC indices were 538 ± 80 ms and 539 ± 86 ms. Age correlated negatively with medial (r = −0.40, p < 0.001) and lateral (r = −0.29, p = 0.012) dGEMRIC index. Subjects with clinical knee OA had significantly lower medial dGEMRIC index; however, no association was found for BMI. Varus alignment correlated with lower medial dGEMRIC index (r = −0.43, p < 0.006), while quadriceps strength correlated positively with lateral dGEMRIC index (r = 0.32, p = 0.008). There was also a negative correlation between serum leptin and lateral dGEMRIC index in women (r = −0.39, p = 0.035), with a trend in men (r = −0.52, p = 0.08). There were weak associations with physical disability, as self-reported on the WOMAC questionnaire.Conclusion.In obese subjects, knee dGEMRIC index was associated with age, clinical knee OA, abnormal tibiofemoral alignment, and quadriceps strength. Longitudinal studies are required to assess the potential for improvement in dGEMRIC index with interventions such as strength training.
Spondyloarthritis Is Associated with Poor Function and Physical Health-Related Quality of Life
Authors: SINGH JASVINDER A. , STRAND VIBEKE 
Published: April 2009

Objective.To study physical function and health-related quality of life (HRQOL) in US veterans with spondyloarthritis (SpA).Methods.In a postal survey of 70,334 eligible veterans, demographics, performance of activities of daily living (ADL), and HRQOL, by Veterans Short Form-36, were queried; 58% responded (n = 40,508). Databases providedInternational Classification of Diseases, 9th ed. codes for ankylosing spondylitis (AS), psoriatic (PsA) and reactive arthritis (ReA), comorbidities, and demographics. Multivariable linear/logistic regressions compared ADL limitations and HRQOL in SpA versus non-SpA, and predictors in SpA.Results.Six hundred sixty-four veteran respondents had diagnoses of SpA: AS, n = 100; PsA, n = 551; ReA, n = 13. Veterans with AS, PsA, and ReA had significantly more limitations in dressing (44%, 23%, 24% vs 22%; p = 0.0002), transferring (57%, 42%, 64% vs 39%; p = 0.0006), walking (74%, 57%, 67% vs 54%; p = 0.0005), and overall mean ADL limitations (2.5, 1.7, 2.1 vs 1.6; p < 0.0001) compared to veterans without SpA, after multivariable adjustment. Limitations in each ADL in patients with SpA were 1.3–5.3 times that of an age-matched US cohort. Physical HRQOL was significantly lower compared with non-SpA veterans (p < 0.0001 for physical component summary, physical functioning, role physical, and bodily pain; p = 0.004 for general health) and age-sex-matched US norms; all differences exceeded clinically meaningful threshold of 5–10 units. More limitations in ADL were significantly associated with lower physical component summary scores in patients with AS and with lower physical and mental component summary scores in PsA.Conclusion.After adjustment for differences in demographics and comorbidities, poorer physical function and HRQOL were observed in patients with SpA. Strategies focused to improve/maintain functional status are important for treatment of SpA.
Less Radiographic Progression with Adalimumab Plus Methotrexate Versus Methotrexate Monotherapy Across the Spectrum of Clinical Response in Early Rheumatoid Arthritis
Authors: EMERY PAUL , GENOVESE MARK C. , van VOLLENHOVEN RONALD , SHARP JOHN T. , PATRA KAUSHIK , SASSO ERIC H. 
Published: April 2009

Objective.To determine the relationship between radiographic progression and clinical response for adalimumab plus methotrexate (MTX) versus either monotherapy in patients with early rheumatoid arthritis (RA) in the PREMIER study.Methods.Patients with early RA who received adalimumab plus MTX (n = 240), adalimumab (n = 222), or MTX (n = 216) were grouped by American College of Rheumatology (ACR) response, 28-joint Disease Activity Score (DAS28), or remission-like state [tender joint count (TJC) = 0; DAS28 < 2.6; swollen joint count = 0; ACR100] at 26 and 104 weeks. Radiographic progression was assessed by cumulative probability plots, mean changes in total Sharp score (ΔTSS), and percentages of progressors (ΔTSS > 0.5).Results.Across the spectrum of clinical outcomes, including ACR20 nonresponses and remission-like responses, therapy with adalimumab plus MTX permitted less radiographic progression at Weeks 26 and 104 than MTX monotherapy. Adalimumab monotherapy was generally intermediate. A strong, proportional relationship was observed between clinical response and radiographic efficacy only for MTX monotherapy. The monotherapies approximated the radiographic efficacy of adalimumab plus MTX only among remission-like responders, although progression was significantly greater with MTX monotherapy versus adalimumab plus MTX for patients with TJC = 0. Concurrent clinical (DAS28 < 2.6) and radiographic (ΔTSS ≤ 0.5) remission was significantly more frequent at Week 104 with adalimumab plus MTX (45%) than with adalimumab (25%) or MTX (18%) monotherapy.Conclusion.In patients with early RA, adalimumab plus MTX resulted in less radiographic progression than MTX monotherapy across the spectrum of clinical response, including ACR20 non-responses and remission-like responses.
Psychometric Properties of the EuroQol-5D and Short Form-6D in Patients with Systemic Lupus Erythematosus
Authors: AGGARWAL ROHIT , WILKE CAITLYN T. , PICKARD A. SIMON , VATS VIKRANT , MIKOLAITIS RACHEL , FOGG LEWIS , BLOCK JOEL A. , JOLLY MEENAKSHI 
Published: April 2009

Objective.Health related quality of life (HRQOL) is an important patient-reported outcome in systemic lupus erythematosus (SLE). We evaluated the psychometric properties of 2 widely used preference-based generic HRQOL measures, EuroQol-5D (EQ-5D) and Short Form-6D (SF-6D), among United States patients with SLE.Methods.Patients with SLE enrolled at an academic institution were assessed for self-reported generic HRQOL (EQ-5D, Medical Outcomes Study SF-36), disease activity, and disease damage SF-6D. Physical Component Score (PCS) and Mental Component Score (MCS) were calculated from SF-36. Criterion validity, convergent validity, and known-groups comparisons were evaluated for EQ-5D and SF-6D. Sensitivity to change (t tests, effect size) was evaluated in a subset of the cohort followed longitudinally.Results.One hundred sixty-seven patients with SLE were enrolled. Related domains on the EQ-5D and SF-36 correlated strongly, e.g., mobility and physical functioning (r = 0.60), whereas unrelated domains showed weak to moderate correlation. EQ-5D index, EQ-5D visual analog scale, and SF-6D score correlated strongly among each other as well as with most domains of SF-36. Both EQ-5D and SF-6D indices differentiated among patients of varied disease severity. EQ-5D and SF-6D were found to be sensitive to self-reported change in health but insensitive to change in disease activity longitudinally. Disease activity and damage showed weak correlation with HRQOL measures.Conclusion.The SF-6D and EQ-5D exhibited satisfactory psychometric properties for use among US patients with SLE. Measures of disease activity and damage were weakly correlated with HRQOL, suggesting that HRQOL is an important complementary source of information about patients with SLE.