Design, optimization and optical performance study of tripod heliostat for solar power tower plant

Heliostats account for about 50% of the capital cost of power towers. In conventional heliostats with vertical pedestals and azimuth-elevation drives, the support structure contributes 40-50% of this cost due to heavy cantilever arms required by the large spanning structures. Additional costs are imposed by costly, difficult to maintain drive mechanisms. Here we show that a tripod heliostat can substantially address these shortcomings. We have presented the protocol and results of systematic structural analysis of heliostats with aperture areas of 62 and 100 m(2). We have included effects of shape on load reaction and structure cost. An in-house ray-tracing software is incorporated to estimate the performance penalties due to deformation under gravity and wind loads. The analysis shows that the additional energy collection by a less-stiff, larger heliostat more than offsets the spillage due to the greater deformation of the same. We have demonstrated that the economics of power towers are strongly governed by the structural cost of the heliostats rather than by their optical performance. We have brought down the cost of a tripod heliostat to $ 72/m(2) which is less than half that of the conventional systems and meets the target set by the US National Academy of Engineering. (C) 2017 Elsevier Ltd. All rights reserved

Circulating secretory IgA antibodies against cyclic citrullinated peptides in early rheumatoid arthritis associate with inflammatory activity and smoking

Background: A possible association between mucosal immunization and inflammation, as well as the initiation and propagation of rheumatoid arthritis (RA), is attracting renewed interest. The aim of this study was to evaluate the possible occurrence and clinical correlations of circulating secretory immunoglobulin A (SIgA) antibodies against the second-generation cyclic citrullinated peptides (CCP) among patients with recent-onset RA followed prospectively over 3 years. Methods: Baseline serum samples from 636 patients with recent-onset RA were analyzed for SIgA anti-CCP antibodies by using an enzyme-linked immunosorbent assay with a secondary antibody directed against secretory component. SIgA anti-CCP status at baseline was analyzed in relation to smoking, HLA-DRB1/shared epitope (SE), and the disease course over 3 years. Significant findings were evaluated in regression analysis that included age, sex, smoking, and SE. Results: Seventeen percent of the patients tested positive for circulating SIgA anti-CCP, and the occurrence was confirmed by detection of secretory component in an affinity-purified IgA anti-CCP fraction. SIgA anti-CCP positivity at baseline was associated with slightly higher baseline erythrocyte sedimentation rate (ESR) (mean 38 vs. 31 mm/first hour, p = 0.004) and C-reactive protein (CRP) (mean 30 vs. 23 mg/L, p = 0.047). During follow-up, SIgA anti-CCP-positive patients had a higher mean AUC regarding ESR (adjusted p = 0.003), although there were no significant differences regarding CRP, tender and swollen joint counts, or radiological joint damage (median Larsen progression 1.0 vs. 1.0, p = 0.22). SIgA anti-CCP was associated significantly with smoking (79 % ever smokers among SIgA anti-CCP-positive patients vs. 59 % in SIgA anti-CCP-negative patients, adjusted OR 2.19, 95 % CI 1.01-4.37, p = 0.027) but not with carriage of the SE (80 % vs. 73 %, p = 0.62). Conclusions: Circulating SIgA anti-CCP, which is present in a subgroup of patients with early RA, is not related to SE, but it is environmentally linked to cigarette smoking. This finding strengthens the hypothesis that immunization against citrullinated peptides and/or proteins may occur at mucosal surfaces of the airways. Analysis of SIgA antibodies in serum may be a convenient and more versatile means to investigate the "mucosal connection" in RA compared with analyses in mucosal fluid samples.Funding Agencies|King Gustav Vs 80-year Foundation; Swedish Medical Society; Reinhold Sund Foundation; Ostergotland County Council</p

Two years after pandemic influenza A/2009/H1N1: What have we learned?

The world had been anticipating another influenza pandemic since the last one in 1968. The pandemic influenza A H1N1 2009 virus (A/2009/H1N1) finally arrived, causing the first pandemic influenza of the new millennium, which has affected over 214 countries and caused over 18,449 deaths. Because of the persistent threat from the A/H5N1 virus since 1997 and the outbreak of the severe acute respiratory syndrome (SARS) coronavirus in 2003, medical and scientific communities have been more prepared in mindset and infrastructure. This preparedness has allowed for rapid and effective research on the epidemiological, clinical, pathological, immunological, virological, and other basic scientific aspects of the disease, with impacts on its control. A PubMed search using the keywords "pandemic influenza virus H1N1 2009" yielded over 2,500 publications, which markedly exceeded the number published on previous pandemics. Only representative works with relevance to clinical microbiology and infectious diseases are reviewed in this article. A significant increase in the understanding of this virus and the disease within such a short amount of time has allowed for the timely development of diagnostic tests, treatments, and preventive measures. These findings could prove useful for future randomized controlled clinical trials and the epidemiological control of future pandemics. © 2012, American Society for Microbiology. All Rights Reserved.link_to_subscribed_fulltex

The Role of Alliums and Their Sulfur and Selenium Constituents in Cancer Prevention

Garlic and its sulfur and selenium-containing components are widely known for their cancer preventive activities primarily in preclinical in vitro and in vivo model systems. Most of our common foods including garlic contain very low levels of selenium compounds relative to those of sulfur. Humans consume a substantial portion of their dietary sulfur and selenium in organic forms. Selenium-enriched foods such as garlic, broccoli and wheat are more effective chemopreventive agents than the corresponding regular dietary items. Naturally occurring and synthetic organoselenium compounds are superior cancer chemopreventive agents compared to their corresponding sulfur analogs. Mechanistic studies demonstrate that sulfur and selenium compounds are capable of cell growth inhibition, cell cycle arrest, induction of apoptosis, alterations of phase I and phase II enzyme activities, and histone deacetylase (HDAC) inhibition. The fact that organosulfur and organoselenium compounds can target multiple pathways suggests that these agents can be used directly as chemopreventive and/or therapeutic agents or in combination with other medicinal compounds. The effect of these agents on the aforementioned parameters varies depending on the dose and form (structure) and whether cells are normal or transformed. Whether the protective effects observed in animals and in cell cultures can be applicable to humans remain to be determined. Thus, studies using genomic, proteomic, and metabolomic techniques in well designed small-scale clinical trials are needed to unequivocally evaluate the potential of allium vegetable constituents on biomarkers of risk for specific cancers prior to entering into long-term expensive phase III clinical chemoprevention trials