1,810 research outputs found
Scientific complications and controversies noted in the field of CdS/CdTe thin film solar cells and the way forward for further development
Cadmium telluride-based solar cell is the most successfully commercialised thin film solar cell today. The laboratory-scale small devices have achieved ~ 22%, and commercial solar panels have reached ~ 18% conversion efficiencies. However, there are various technical complications and some notable scientific contradictions that appear in the scientific literature published since the early 1970s. This review paper discusses some of these major complications and controversies in order to focus future research on issues of material growth and characterisation, post-growth processing, device architectures and interpretation of the results. Although CdTe can be grown using more than 14 different growth techniques, successful commercialisation has been taken place using close-space sublimation and electrodeposition techniques only. The experimental results presented in this review are mainly based on electrodeposition. Historical trends of research and commercial successes have also been discussed compared to the timeline of novel breakthroughs in this field. Deeper understanding of these issues may lead to further increase in conversion efficiencies of this solar cell. Some novel ideas for further development of thin film solar cells are also discussed towards the end of this paper
An observational prospective study of topical acidified nitrite for killing methicillin-resistant Staphylococcus aureus (MRSA) in contaminated wounds
Background Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Findings Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Conclusions Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue
Allogeneic hematopoietic stem cell transplantation could improve survival of cytogenetically normal adult acute myeloid leukemia patients with DNMT3A mutations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115978/1/ajh24135.pd
A Gene-Based Association Method for Mapping Traits Using Reference Transcriptome Data
Genome-wide association studies (GWAS) have identified thousands of variants robustly associated with complex traits. However, the biological mechanisms underlying these associations are, in general, not well understood. We propose a gene-based association method called PrediXcan that directly tests the molecular mechanisms through which genetic variation affects phenotype. The approach estimates the component of gene expression determined by an individual’s genetic profile and correlates ‘imputed’ gene expression with the phenotype under investigation to identify genes involved in the etiology of the phenotype. Genetically regulated gene expression is estimated using whole-genome tissue-dependent prediction models trained with reference transcriptome data sets. PrediXcan enjoys the benefits of gene-based approaches such as reduced multiple-testing burden and a principled approach to the design of follow-up experiments. Our results demonstrate that PrediXcan can detect known and new genes associated with disease traits and provide insights into the mechanism of these associations
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Impact of Antithrombotic Regimen on Mortality, Ischemic, and Bleeding Outcomes after Transcatheter Aortic Valve Replacement
Introduction: Optimal antithrombotic therapy after transcatheter aortic valve replacement (TAVR) remains unclear. We evaluated the association between antithrombotic regimens and outcomes in TAVR patients. Methods: We retrospectively analyzed consecutive patients who underwent TAVR at a single academic center from April 2009 to March 2014. Antithrombotic regimens were classified as single or dual antiplatelet therapy (AP), single antiplatelet plus anticoagulant (SAC), or triple therapy (TT). The primary endpoint was a composite of death, myocardial infarction (MI), stroke, and major bleeding. Adjusted hazard ratios (HRs) were obtained with best subset variable selection methods using bootstrap resampling. Results: Of 246 patients who underwent TAVR, 241 were eligible for analysis with 133, 88, and 20 patients in the AP, SAC, and TT groups, respectively. During a median 2.1-year follow-up, 53.5% had at least one endpoint—the most common was death (68%), followed by major bleeding (23%), stroke (6%), and MI (3%). At 2 years, the composite outcome occurred in 70% of TT, 42% of SAC, and 31% of AP patients. Compared to AP, adjusted HRs for the composite outcome were 2.88 [95% Confidence intervals (CI) (1.61–5.16); p = 0.0004] and 1.66 (95% CI [1.13-2.42]; p = 0.009) in the TT and SAC groups, respectively. Mortality rates at 2 years were 61% in the TT, 32% in the SAC, and 26% in the AP groups (p = 0.005). Conclusions: The risk of the composite outcome of death, MI, stroke, or major bleeding at 2-year follow-up was significantly higher in TAVR patients treated with TT or SAC versus AP, even after multivariate adjustment
In vitro induction of melanin synthesis and extrusion by tamoxifen
Physical appearance has significant importance psychologically and socially, with skin and hair being of prime relevance. Effective ingredients that modulate melanin synthesis are of growing interest. Tamoxifen, a widely used selective oestrogen receptor modulator, SERM, was described occasionally in medical case reports as causing grey hair repigmentation. This work aimed to study, in vitro, the effect of tamoxifen and 4-hydroxy-tamoxifen, one of its most bioactive derivatives, on melanin production in human melanocytes.Teresa Matam a holds a grant from FCT–Fundação para a Ciência
e a Tecnologia (SFRH/BPD/47555/2008). This work was supported
by FEDER through POFC–COMPETE and by national funds from
FCT through the project PEst-C/BIA/UI4050/2011
Meeting Report: The Dallas Consensus Conference on Liver Transplantation for Alcohol Associated Hepatitis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153137/1/lt25681.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153137/2/lt25681_am.pd
The association between histamine 2 receptor antagonist use and Clostridium difficile infection: a systematic review and meta-analysis.
Background
Clostridium difficile infection (CDI) is a major health problem. Epidemiological evidence suggests that there is an association between acid suppression therapy and development of CDI.
Purpose
We sought to systematically review the literature that examined the association between histamine 2 receptor antagonists (H2RAs) and CDI.
Data source
We searched Medline, Current Contents, Embase, ISI Web of Science and Elsevier Scopus from 1990 to 2012 for all analytical studies that examined the association between H2RAs and CDI.
Study selection
Two authors independently reviewed the studies for eligibility.
Data extraction
Data about studies characteristics, adjusted effect estimates and quality were extracted.
Data synthesis
Thirty-five observations from 33 eligible studies that included 201834 participants were analyzed. Studies were performed in 6 countries and nine of them were multicenter. Most studies did not specify the type or duration of H2RAs therapy. The pooled effect estimate was 1.44, 95% CI (1.22–1.7), I2 = 70.5%. This association was consistent across different subgroups (by study design and country) and there was no evidence of publication bias. The pooled effect estimate for high quality studies was 1.39 (1.15–1.68), I2 = 72.3%. Meta-regression analysis of 10 study-level variables did not identify sources of heterogeneity. In a speculative analysis, the number needed to harm (NNH) with H2RAs at 14 days after hospital admission in patients receiving antibiotics or not was 58, 95% CI (37, 115) and 425, 95% CI (267, 848), respectively. For the general population, the NNH at 1 year was 4549, 95% CI (2860, 9097).
Conclusion
In this rigorous systematic review and meta-analysis, we observed an association between H2RAs and CDI. The absolute risk of CDI associated with H2RAs is highest in hospitalized patients receiving antibiotics
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