600 research outputs found
Quantitative copper measurement in oxidized p-type silicon wafers using microwave photoconductivity decay
We propose a method to measure trace copper contamination in p-type silicon using the microwave photoconductivity decay (μ-PCD) technique. The method is based on the precipitation of interstitial copper, activated by high-intensity light, which results in enhanced minority carrier recombination activity. We show that there is a quantitative correlation between the enhanced recombination rate and the Cu concentration by comparing μ-PCD measurements with transient ion drift and total reflection x-ray fluorescence measurements. The results indicate that the method is capable of measuring Cu concentrations down to 10exp10cm−3. There are no limitations to wafer storage time if corona charge is used on the oxidized wafer surfaces as the charge prevents copper outdiffusion. We briefly discuss the role of oxide precipitates both in the copperprecipitation and in the charge carrier recombination processes.Peer reviewe
Physiological effects of oral glucosamine on joint health: Current status and consensus on future research priorities
The aim of this paper was to provide an overview of the current knowledge and understanding of the potential beneficial physiological effects of glucosamine (GlcN) on joint health. The objective was to reach a consensus on four critical questions and to provide recommendations for future research priorities. To this end, nine scientists from Europe and the United States were selected according to their expertise in this particular field and were invited to participate in the Hohenheim conference held in Aug
Prognostic factors for abatacept retention in patients who received at least one prior biologic agent: an interim analysis from the observational, prospective ACTION study
Background: The emergence of new therapies for the treatment of rheumatoid arthritis (RA), the paucity of head-to-head studies, and the heterogeneous nature of responses to current biologics highlight the need for the identification of prognostic factors for treatment response and retention in clinical practice. Prognostic factors for patient retention have not been explored thoroughly despite data for abatacept and other biologics being available from national registries. Real-world data from the ACTION study may supplement the findings of randomized controlled trials and show how abatacept is used in clinical practice. The aim of this interim analysis was to identify prognostic factors for abatacept retention in patients with RA who received at least one prior biologic agent. Methods: A large, international, non-interventional cohort of patients with moderate-to-severe RA who initiated intravenous abatacept in Canada and Europe (May 2008–January 2011) enrolled in the ACTION study. Potential prognostic factors for retention in this interim analysis (data cut-off February 2012; including patients from Canada, Germany, Greece, and Italy) were baseline demographics and disease characteristics, medical history, and previous and concomitant medication. Clinically relevant variables with p ≤ 0.20 in univariate analysis and no collinearity were entered into a Cox proportional hazards regression model, adjusted for clustered data. Variables with p ≤ 0.10 were retained in the final model (backward selection). Results: The multivariate model included 834 patients. Anti-cyclic citrullinated peptide (CCP) antibody positivity (hazard ratio [95 % confidence interval]: 0.55 [0.40, 0.75], p < 0.001), failure of <2 prior anti-tumor necrosis factors (TNFs) (0.71 [0.56, 0.90], p = 0.005 versus ≥2 prior anti-TNFs), and cardiovascular comorbidity at abatacept initiation (0.48 [0.28, 0.83], p = 0.009) were associated with lower risk of abatacept discontinuation. Patients in Greece and Italy were less likely to discontinue abatacept than patients in Germany and Canada (Greece: 0.30 [0.16, 0.58]; Italy: 0.50 [0.33, 0.76]; Canada: 1.04 [0.78, 1.40], p < 0.001 versus Germany). Conclusions: Real-world prognostic factors for abatacept retention include anti-CCP positivity and fewer prior anti-TNF failures. Differences in retention rates between countries may reflect differences in healthcare systems. The finding that abatacept has potential advantages in patients with cardiovascular comorbidities needs to be confirmed in further research
an interim analysis from the observational, prospective ACTION study
Background The emergence of new therapies for the treatment of rheumatoid
arthritis (RA), the paucity of head-to-head studies, and the heterogeneous
nature of responses to current biologics highlight the need for the
identification of prognostic factors for treatment response and retention in
clinical practice. Prognostic factors for patient retention have not been
explored thoroughly despite data for abatacept and other biologics being
available from national registries. Real-world data from the ACTION study may
supplement the findings of randomized controlled trials and show how abatacept
is used in clinical practice. The aim of this interim analysis was to identify
prognostic factors for abatacept retention in patients with RA who received at
least one prior biologic agent. Methods A large, international, non-
interventional cohort of patients with moderate-to-severe RA who initiated
intravenous abatacept in Canada and Europe (May 2008–January 2011) enrolled in
the ACTION study. Potential prognostic factors for retention in this interim
analysis (data cut-off February 2012; including patients from Canada, Germany,
Greece, and Italy) were baseline demographics and disease characteristics,
medical history, and previous and concomitant medication. Clinically relevant
variables with p ≤ 0.20 in univariate analysis and no collinearity were
entered into a Cox proportional hazards regression model, adjusted for
clustered data. Variables with p ≤ 0.10 were retained in the final model
(backward selection). Results The multivariate model included 834 patients.
Anti-cyclic citrullinated peptide (CCP) antibody positivity (hazard ratio [95
% confidence interval]: 0.55 [0.40, 0.75], p < 0.001), failure of <2 prior
anti-tumor necrosis factors (TNFs) (0.71 [0.56, 0.90], p = 0.005 versus ≥2
prior anti-TNFs), and cardiovascular comorbidity at abatacept initiation (0.48
[0.28, 0.83], p = 0.009) were associated with lower risk of abatacept
discontinuation. Patients in Greece and Italy were less likely to discontinue
abatacept than patients in Germany and Canada (Greece: 0.30 [0.16, 0.58];
Italy: 0.50 [0.33, 0.76]; Canada: 1.04 [0.78, 1.40], p < 0.001 versus
Germany). Conclusions Real-world prognostic factors for abatacept retention
include anti-CCP positivity and fewer prior anti-TNF failures. Differences in
retention rates between countries may reflect differences in healthcare
systems. The finding that abatacept has potential advantages in patients with
cardiovascular comorbidities needs to be confirmed in further research
Smoking and response to rituximab in rheumatoid arthritis : results from an international European collaboration
Objectives: To investigate whether smoking habits predict response to rituximab (RTX) in rheumatoid arthritis (RA). Method: We included patients from the CERERRA international cohort receiving the first treatment cycle with available smoking status (n = 2481, smokers n = 528, non-current smokers n = 1953) and at least one follow-up visit. Outcome measures were change in Disease Activity Score based on 28-joint count (Delta DAS28) and European League Against Rheumatism (EULAR) good response at 6 months, with non-current smokers as the referent group. Results: Compared with non-smokers at baseline, smokers were more often rheumatoid factor (RF)/anti-citrullinated protein antibody (ACPA) positive and males, had shorter disease duration, lower DAS28 and Health Assessment Questionnaire (HAQ) score, a higher number of prior biological disease-modifying anti-rheumatic drugs, and were more likely to receive concomitant conventional synthetic disease-modifying anti-rheumatic drug (csDMARDs). Disease activity had decreased less in smokers at 6 months (Delta DAS28 = 1.5 vs 1.7, p = 0.006), although the difference was no longer significant after correction for baseline DAS28 (p = 0.41). EULAR good response rates did not differ between smokers and non-smokers overall or stratified by RF/ACPA status, although smokers had lower good response rates among seronegative patients (ACPA-negative: 6% vs 14%, RF-negative: 11% vs 18%). Smoking did not predict good response [odds ratio (OR) = 1.04, 95% confidence interval (CI) = 0.76-1.41], while ACPA, DAS28, HAQ, and concomitant csDMARDs were significant predictors for good response. However, when stratified by country, smokers were less likely to achieve good response in Sweden (unadjusted OR = 0.24, 95% CI = 0.07-0.89), and a trend was seen in the Czech Republic (OR = 0.45, 95% CI = 0.16-1.02). Conclusion: In this large, observational, multinational RA cohort, smokers starting RTX differed from non-smokers by having shorter disease duration and lower disease activity, but more previous treatments. The overall results do not support smoking as an important predictor for response to RTX in patients with RA.Peer reviewe
An assessment of false discovery rates and statistical significance in label-free quantitative proteomics with combined filters
Global Research Alliance N2O chamber methodology guidelines: Design considerations
Terrestrial ecosystems, both natural ecosystems and agroecosystems, generate greenhouse gases (GHGs). The chamber method is the most common method to quantify GHG fluxes from soil–plant systems and to better understand factors affecting their generation and mitigation. The objective of this study was to review and synthesize literature on chamber designs (non‐flow‐through, non‐steady‐state chamber) and associated factors that affect GHG nitrous oxide (N2O) flux measurement when using chamber methods. Chamber design requires consideration of many facets that include materials, insulation, sealing, venting, depth of placement, and the need to maintain plant growth and activity. Final designs should be tailored, and bench tested, in order to meet the nuances of the experimental objectives and the ecosystem under study while reducing potential artifacts. Good insulation, to prevent temperature fluctuations and pressure changes, and a high‐quality seal between base and chamber are essential. Elimination of pressure differentials between headspace and atmosphere through venting should be performed, and designs now exist to eliminate Venturi effects of earlier tube‐type vent designs. The use of fans within the chamber headspace increases measurement precision but may alter the flux. To establish best practice recommendations when using fans, further data are required, particularly in systems containing tall plants, to systematically evaluate the effects that fan speed, position, and mixing rate have on soil gas flux.Peer reviewe
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