bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave Hybrid Post‐Heat Treatment of Reaction Sintered Alumina/Lanthanum Hexaaluminate Composite Ceramics
Authors: Negahdari Zahra , Willert‐Porada Monika 
Published: March 2010

AbstractOne of the main problems in development of in situ reaction sintered alumina/lanthanum hexaaluminate composite ceramics is achievement of simultaneous densification and in situ formation of lanthanum hexaaluminate (LHA) platelets inside the matrix. Microwave hybrid post‐sintering was investigated as a method to enhance the solid‐state reaction of LHA formation and the densification of composite ceramics with 2.8–80 vol% LHA. Comparison of the conventionally and microwave assisted sintered alumina/lanthanum hexaaluminate composite ceramics revealed that utilization of microwave heating in second stage of sintering could enhance the solid‐state reaction, the densification, and the anisotropic grain growth of the LHA platelets in ceramics containing more than 20 vol% LHA and for heat treatment at 1500 °C.
Nanomorphology and Charge Generation in Bulk Heterojunctions Based on Low‐Bandgap Dithiophene Polymers with Different Bridging Atoms
Authors: Morana Mauro , Azimi Hamed , Dennler Gilles , Egelhaaf Hans‐Joachim , Scharber Markus , Forberich Karen , Hauch Jens , Gaudiana Russell , Waller David , Zhu Zenghuo , Hingerl Kurt , van Bavel Svetlana S. , Loos Joachim , Brabec Christoph J. 
Published: March 2010

AbstractCarbon bridged (C‐PCPDTBT) and silicon‐bridged (Si‐PCPDTBT) dithiophene donor–acceptor copolymers belong to a promising class of low bandgap materials. Their higher field‐effect mobility, as high as 10−2 cm2 V−1 s−1 in pristine films, and their more balanced charge transport in blends with fullerenes make silicon‐bridged materials better candidates for use in photovoltaic devices. Striking morphological changes are observed in polymer:fullerene bulk heterojunctions upon the substitution of the bridging atom. XRD investigation indicates increased π–π stacking in Si‐PCPDTBT compared to the carbon‐bridged analogue. The fluorescence of this polymer and that of its counterpart C‐PCPDTBT indicates that the higher photogeneration achieved in Si‐PCPDTBT:fullerene films (with either [C60]PCBM or [C70]PCBM) can be correlated to the inactivation of a charge‐transfer complex and to a favorable length of the donor–acceptor phase separation. TEM studies of Si‐PCPDTBT:fullerene blended films suggest the formation of an interpenetrating network whose phase distribution is comparable to the one achieved in C‐PCPDTBT:fullerene using 1,8‐octanedithiol as an additive. In order to achieve a balanced hole and electron transport, Si‐PCPDTBT requires a lower fullerene content (between 50 to 60 wt%) than C‐PCPDTBT (more than 70 wt%). The Si‐PCPDTBT:[C70]PCBM OBHJ solar cells deliver power conversion efficiencies of over 5%.
Universal Behavior and Electric‐Field‐Induced Structural Transition in Rare‐Earth‐Substituted BiFeO3
Authors: Kan Daisuke , Pálová Lucia , Anbusathaiah Varatharajan , Cheng Ching Jung , Fujino Shigehiro , Nagarajan Valanoor , Rabe Karin M. , Takeuchi Ichiro 
Published: March 2010

AbstractThe discovery of a universal behavior in rare‐earth (RE)‐substituted perovskite BiFeO3 is reported. The structural transition from the ferroelectric rhombohedral phase to an orthorhombic phase exhibiting a double‐polarization hysteresis loop and substantially enhanced electromechanical properties is found to occur independent of the RE dopant species. The structural transition can be universally achieved by controlling the average ionic radius of the A‐site cation. Using calculations based on first principles, the energy landscape of BiFeO3 is explored, and it is proposed that the origin of the double hysteresis loop and the concomitant enhancement in the piezoelectric coefficient is an electric‐field‐induced transformation from a paraelectric orthorhombic phase to the polar rhombohedral phase.
Bottom‐Up Engineering of Subnanometer Copper Diffusion Barriers Using NH2‐Derived Self‐Assembled Monolayers
Authors: Caro Arantxa Maestre , Armini Silvia , Richard Olivier , Maes Guido , Borghs Gustaaf , Whelan Caroline M. , Travaly Youssef 
Published: March 2010

AbstractA 3‐aminopropyltrimethoxysilane‐derived self‐assembled monolayer (NH2SAM) is investigated as a barrier against copper diffusion for application in back‐end‐of‐line (BEOL) technology. The essential characteristics studied include thermal stability to BEOL processing, inhibition of copper diffusion, and adhesion to both the underlying SiO2 dielectric substrate and the Cu over‐layer. Time‐of‐flight secondary ion mass spectrometry and X‐ray spectroscopy (XPS) analysis reveal that the copper over‐layer closes at 1–2‐nm thickness, comparable with the 1.3‐nm closure of state‐of‐the‐art Ta/TaN Cu diffusion barriers. That the NH2SAM remains intact upon Cu deposition and subsequent annealing is unambiguously revealed by energy‐filtered transmission electron microscopy supported by XPS. The SAM forms a well‐defined carbon‐rich interface with the Cu over‐layer and electron energy loss spectroscopy shows no evidence of Cu penetration into the SAM. Interestingly, the adhesion of the Cu/NH2SAM/SiO2 system increases with annealing temperature up to 7.2 J m−2 at 400 °C, comparable to Ta/TaN (7.5 J m−2 at room temperature). The corresponding fracture analysis shows that when failure does occur it is located at the Cu/SAM interface. Overall, these results demonstrate that NH2SAM is a suitable candidate for subnanometer‐scale diffusion barrier application in a selective coating for copper advanced interconnects.
CFD simulation of transverse vibration effects on radial temperature profile and thermal entrance length in laminar flow
Authors: Eesa Muhammad , Barigou Mostafa 
Published: March 2010

AbstractRadial heat transfer in laminar pipe flow is characterized by a wide temperature distribution over the pipe cross‐section. We use a validated Computational Fluid Dynamics (CFD) model to show that the superimposition of a transverse vibration on the steady laminar flow of a Newtonian fluid moving in a pipe with an isothermal wall, generates considerable chaotic flow and radial mixing which result in a large enhancement in wall heat transfer as well as a considerably more uniform radial temperature field. Transverse vibration also causes the temperature profile to develop very rapidly in the axial direction reducing the thermal entrance length by a large factor. These effects are dependent on vibration amplitude and frequency, and fluid viscosity. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Implementation of new working methods in the floor‐laying trade: Long‐term effects on knee load and knee complaints
Authors: Jensen Lilli Kirkeskov , Friche Claus 
Published: March 2010

AbstractBackgroundThis study compared floor laying using new working methods involving standing up, to the traditional methods involving working on one's knees.MethodsThe study group, 216 subjects, completed a training class in the use of the new floor‐laying methods, and received free tools and advice in their use. The control group, 454 subjects, did not get any training, but were free to use the new methods if they wished. In a 2‐year‐follow‐up the effects were evaluated by questionnaires and by in‐depth interviews of industry representatives. Regression analysis was used to control for age, body mass index (BMI), and self‐reported stress. The quality of the work and time used to perform it comparing the new methods and the traditional methods was evaluated.ResultsTwo years after the training, 38% of participants in the study group used the new working methods weekly or daily compared with 16% of the control group. The risk was at least double for serious knee complaints among floor layers who had not used the new working methods. There were no increased risks for other musculoskeletal complaints involving any other part of the body associated with the use of the new method.ConclusionsWithin a 2‐year time period, the introduction of new working methods in the floor‐laying trade has succeeded. More efforts are needed to sustain the use of the methods among those workers who have been trained and to introduce the methods to those workers who do not yet use them. Am. J. Ind. Med. 53: 615–627, 2010. © 2010 Wiley‐Liss, Inc.
Ethical issues faced by field primatologists: asking the relevant questions
Authors: Fedigan Linda Marie 
Published: March 2010

AbstractField primatologists face unusual ethical issues. We study animals rather than people and receive research approval from animal care rather than ethics committees. However, animal care evaluation forms are developed from concerns about laboratory animal research and are based on the “Three R's” for humane treatment of captive experimental subjects (replacement, reduction and refinement), which are only debatably relevant to field research. Scientists who study wild, free‐ranging primates in host countries experience many ethical dilemmas seldom dealt with in animal care forms. This paper reviews the ethical issues many field primatologists say they face and how these might be better addressed by animal care forms. The ethical issues arising for field researchers are divided into three categories: “Presence, Protocols and People” and for each the most frequent issues are described. The most commonly mentioned ethical concern arising from our presence in the field is the possibility of disease transmission. Although most primate field studies employ only observational protocols, the practice of habituating our study animals to close human presence is an ethical concern for many since it can lessen the animals' fear of all humans, thereby facilitating undesirable behaviors (e.g., crop‐raiding) and rendering them vulnerable to harm. Field primatologists who work in host countries must observe national laws and local traditions. As conservationists, primatologists must often negotiate between the resource needs and cultural practices of local people and the interests of the nonhuman primates. Many say they face more ethical dilemmas arising from human interactions than from research on the animals per se. This review concludes with suggestions for relevant questions to ask on animal care forms, and actions that field primatologists can take to better inform animal care committees about the common ethical issues we experience as well as how to develop guidelines for addressing them. Am. J. Primatol. 72:754–771, 2010. © 2010 Wiley‐Liss, Inc.
Adipocytokines, insulin resistance, and coronary atherosclerosis in rheumatoid arthritis
Authors: Rho Young Hee , Chung Cecilia P. , Solus Joseph F. , Raggi Paolo , Oeser Annette , Gebretsadik Tebeb , Shintani Ayumi , Stein C. Michael 
Published: March 2010

AbstractObjectiveThe prevalence of subclinical coronary atherosclerosis is increased in patients with rheumatoid arthritis (RA), and the increased risk is associated with insulin resistance. Adipocytokines have been linked to obesity, insulin resistance, inflammation, and coronary heart disease in the general population. This study was undertaken to examine the hypothesis that adipocytokines affect insulin resistance and coronary atherosclerosis among patients with RA.MethodsThe coronary calcium score, homeostatic model assessment for insulin resistance (HOMA‐IR) index, and serum adipocytokine (leptin, adiponectin, resistin, and visfatin) concentrations were determined in 169 patients with RA. The independent effect of each adipocytokine on insulin resistance according to the HOMA‐IR index and on coronary artery calcification determined by electron beam computed tomography was assessed in models adjusted for age, race, sex, body mass index (BMI), traditional cardiovascular risk factors, and inflammation mediators. In addition, an interaction analysis was performed to evaluate whether the effect of the HOMA‐IR index on the coronary calcium score is moderated by adipocytokines.ResultsIncreased concentrations of leptin were associated with a higher HOMA‐IR index, even after adjustment for age, race, sex, BMI, traditional cardiovascular risk factors, and inflammation mediators (P < 0.001), but concentrations of visfatin (P = 0.06), adiponectin (P = 0.55), and resistin (P = 0.98) showed no association with the HOMA‐IR index. None of the adipocytokines was independently associated with the coronary calcium score (all P > 0.05). Serum leptin concentrations showed a significant interaction with the HOMA‐IR index (P for multivariate interaction = 0.02). Increasing leptin concentrations attenuated the increased risk of coronary calcification related to insulin resistance. Serum concentrations of the other adipocytokines showed no significant interactions with the HOMA‐IR index (each P > 0.05).ConclusionLeptin is associated with insulin resistance in patients with RA but, paradoxically, attenuates the effects of insulin resistance on coronary calcification.
Frequency of varus and valgus thrust and factors associated with thrust presence in persons with or at higher risk of developing knee osteoarthritis
Authors: Chang Alison , Hochberg Marc , Song Jing , Dunlop Dorothy , Chmiel Joan S. , Nevitt Michael , Hayes Karen , Eaton Charles , Bathon Joan , Jackson Rebecca , Kwoh C. Kent , Sharma Leena 
Published: March 2010

AbstractObjectiveVarus thrust observed during gait has been shown to be associated with a 4‐fold increase in the risk of medial knee osteoarthritis (OA) progression. Valgus thrust is believed to be less common than varus thrust; the prevalence of each is uncertain. Racial differences in risk factors may help explain variations in the natural history of knee OA. We undertook this study to determine the frequency of varus and valgus thrust in African Americans and Caucasians and to identify factors associated with thrust presence.MethodsThe Osteoarthritis Initiative cohort includes men and women who have knee OA or are at increased risk of developing it. Trained examiners assessed thrust presence by gait observation. Logistic regression with generalized estimating equations was used to identify factors associated with thrust presence, and odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated.ResultsCompared with Caucasians, African Americans had lower odds of varus thrust, controlling for age, sex, body mass index (BMI), injury, surgery, disease severity, strength, pain, and alignment in persons without knee OA (adjusted OR 0.50 [95% CI 0.36, 0.72]) and in those with knee OA (adjusted OR 0.46 [95% CI 0.34, 0.61]). Also independently associated with varus thrust were age, sex, BMI, disease severity, strength, and alignment. The odds of valgus thrust were greater for African Americans than for Caucasians in persons without knee OA (adjusted OR 1.69 [95% CI 1.02, 2.80]) and in those with knee OA (adjusted OR 1.98 [95% CI 1.35, 2.91]). Also independently associated with valgus thrust were disease severity and malalignment.ConclusionCompared with Caucasians, African Americans had lower odds of varus thrust and greater odds of valgus thrust. These findings may help explain the difference between these groups in the pattern of OA involvement at the knee.
Association of normal nailfold end row loop numbers with a shorter duration of untreated disease in children with juvenile dermatomyositis
Authors: Ostrowski Rochella A. , Sullivan Christine L. , Seshadri Roopa , Morgan Gabrielle A. , Pachman Lauren M. 
Published: March 2010

AbstractObjectiveTo determine the association of normal numbers of end row loops (ERLs) in nailfold capillaries at the time of diagnosis of juvenile dermatomyositis (DM) with clinical findings in untreated children with the disease and to identify predictors of the development of decreased numbers of ERLs.MethodsClinical and laboratory data from 80 untreated children with juvenile DM were collected. ERL numbers were recorded at the time of diagnosis and at 24 months and 36 months thereafter. The 12 children who had normal ERLs at diagnosis were compared with the remaining 68 children. Outcomes included the duration of untreated disease, the duration of treatment with immunosuppressive medications, family medical history, Disease Activity Score (DAS) for juvenile DM, creatinine phosphokinase level, aldolase level, absolute number of CD3–CD56+/16+ natural killer cells, and von Willebrand factor antigen level. Cross‐sectional and longitudinal analyses were performed.ResultsAt diagnosis, children with normal ERLs had a shorter duration of untreated disease (P = 0.03) and a lower skin DAS (P = 0.045). Over time, an increased likelihood of having decreased numbers of ERLs was associated with a longer duration of untreated disease and with a higher skin DAS.ConclusionThe presence of a normal number of ERLs in juvenile DM appears to be associated with a shorter duration of symptoms and may be a useful indicator of disease chronicity in the newly diagnosed child. Normal ERLs is also associated with a lower skin DAS. The lack of association between normal ERLs and other variables indicates that normal findings on nailfold capillaroscopy should not be used as justification to delay immunosuppressive therapy in children with typical symptoms of juvenile DM.
Involvement of the renin–angiotensin system in the development of vascular damage in a rat model of arthritis: Effect of angiotensin receptor blockers
Authors: Sakuta Takeo , Morita Yoshitaka , Satoh Minoru , Fox David A. , Kashihara Naoki 
Published: March 2010

AbstractObjectiveTo explore the involvement of the renin–angiotensin system (RAS) in the development of vascular damage in adjuvant‐induced arthritis (AIA) in rats.MethodsAngiotensin II (Ang II; 0.25 or 1.0 mg/kg/day) was infused in control rats and rats with AIA for 21 days, and the impact of systemic inflammation on Ang II–induced hypertension, endothelial dysfunction, and vascular hypertrophy was evaluated. Expression of angiotensin II type 1 receptor (AT1R) and angiotensin‐converting enzyme (ACE) in the aortas of rats with AIA were examined by real‐time polymerase chain reaction (PCR) and Western blot analyses. Losartan (3 mg/kg/day) or irbesartan (5 mg/kg/day), both of which are AT1R blockers, was administered orally to rats with AIA for 21 days. In situ superoxide production in aortas was assessed according to the fluorogenic oxidation of dihydroethidium to ethidium. The expression and activity of NAD(P)H oxidases in aortas were examined by real‐time PCR analysis and lucigenin chemiluminescence assay. Endothelial function in rats with AIA treated in vivo or ex vivo with AT1R blockers was also determined.ResultsThe Ang II–induced hypertensive response, endothelial dysfunction, and vascular hypertrophy were exacerbated in rats with AIA. Expression of AT1R and ACE was increased in the aortas of rats with AIA. Both losartan and irbesartan decreased the levels of superoxide and the expression and activity NAD(P)H oxidases in the aortas of rats with AIA. The endothelial dysfunction in AIA was improved by the in vivo or ex vivo treatment with AT1R blockers.ConclusionThe locally activated RAS is involved in the increased vascular oxidative stress and endothelial dysfunction in AIA. Our findings have important implications for clinical approaches to the reduction of cardiovascular risk in patients with rheumatoid arthritis.
Expression of CD44 variant isoforms CD44v3 and CD44v6 is increased on T cells from patients with systemic lupus erythematosus and is correlated with disease activity
Authors: Crispín José C. , Keenan Brendan T. , Finnell Michele D. , Bermas Bonnie L. , Schur Peter , Massarotti Elena , Karlson Elizabeth W. , Fitzgerald Lisa M. , Ergin Sukran , Kyttaris Vasileios C. , Tsokos George C. , Costenbader Karen H. 
Published: March 2010

AbstractObjectiveTo quantify the expression of CD44 and variant isoforms CD44v3 and CD44v6 on T cells from patients with systemic lupus erythematosus (SLE), and to assess correlations of the level of expression of these molecules with disease manifestations.MethodsInformation on clinical and demographic characteristics was collected, and blood samples were obtained from 72 patients with SLE and 32 healthy control subjects matched to the patients by sex, race, and age. Expression of CD44 and variants CD44v3 and v6 on T cell subsets was determined by flow cytometry, and Pearson's correlations of their expression levels with clinical variables, SLE Disease Activity Index (SLEDAI) scores, and presence of lupus nephritis were determined. Wilcoxon's rank sum tests and conditional multivariable regression analyses were applied to identify differences in the expression of CD44 between patients with SLE and healthy controls.ResultsExpression of CD44 was higher on CD4+ and CD8+ T cells from SLE patients compared with controls (P ≤ 0.03). Expression of CD44v3 and CD44v6 was also higher on total T cells and CD4+ and CD8+ T cells from SLE patients compared with controls (P ≤ 0.03). Cell surface levels of CD44v3 on total T cells, CD4+ T cells, and CD8+ T cells as well as cell surface expression of CD44v6 on total T cells and CD4+ T cells were correlated with the SLEDAI score (P < 0.05). The presence of lupus nephritis was associated with the expression of CD44v6 on total T cells, CD4+ T cells, and CD4−CD8− T cells (P < 0.05). Positivity for anti–double‐stranded DNA antibodies was associated with the expression levels of CD44v6 on T cells (P < 0.05).ConclusionThese results indicate that expression levels of CD44v3 and CD44v6 on T cells may represent useful biomarkers of SLE activity.
ADAM15 exerts an antiapoptotic effect on osteoarthritic chondrocytes via up‐regulation of the X‐linked inhibitor of apoptosis
Authors: Böhm Beate , Hess Sandra , Krause Kristin , Schirner Andrea , Ewald Werner , Aigner Thomas , Burkhardt Harald 
Published: March 2010

AbstractObjectiveTo investigate the capacity of ADAM15, a disintegrin metalloproteinase that is up‐regulated in osteoarthritic (OA) cartilage, to protect chondrocytes against apoptosis induced by growth factor deprivation and genotoxic stress.MethodsCaspase 3/7 activity was determined in primary OA and ADAM15‐transfected T/C28a4 chondrocytes upon exposure to the DNA‐damaging agent camptothecin or serum withdrawal. Camptothecin‐induced cytotoxicity was determined by measuring cellular ATP content. (Anti‐)apoptotic proteins were analyzed by immunoblotting, and levels of messenger RNA (mRNA) for X‐linked inhibitor of apoptosis (XIAP) were determined using real‐time polymerase chain reaction. RNA interference was applied for down‐regulation of ADAM15 and XIAP expression. Immunohistochemistry analysis of normal and OA cartilage samples was performed using XIAP‐ and ADAM15‐specific antibodies.ResultsADAM15‐transfected chondrocytes cultured on a collagen matrix displayed significantly reduced caspase 3/7 activity upon serum or intermittent matrix withdrawal, compared with vector‐transfected control cells. Apoptosis induction by camptothecin exposure also led to significantly elevated caspase 3/7 activity and reduced cell viability of the vector‐transfected compared with ADAM15‐transfected chondrocytes. Increased levels of activated caspase 3 and cleaved poly(ADP‐ribose) polymerase were detected in the vector controls. XIAP, an inhibitor of activated caspase 3, was significantly up‐regulated (∼3‐fold) at the protein and mRNA levels in ADAM15‐transfected chondrocytes upon camptothecin treatment. Specific down‐regulation of either ADAM15 or XIAP in OA chondrocytes led to significant sensitization to camptothecin‐induced caspase 3/7 activity. Immunohistochemical analysis revealed low to moderate XIAP expression in normal specimens and markedly increased XIAP staining, colocalizing with ADAM15, in OA cartilage.ConclusionADAM15 conveys antiapoptotic properties to OA chondrocytes that might sustain their potential to better resist the influence of death‐inducing stimuli under pathophysiologic conditions.