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Journal of Solid State Electrochemistry -  相似文献   

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Basal cell carcinoma (BCC) is the most common skin cancer in white populations with an increasing incidence worldwide, thereby imposing an important public health problem. Its etiology is still unclear, but existing data indicate that the risk for BCC development is of multifactorial origin and results from the interplay of both constitutional and environmental factors. Yet, UV radiation (UVR) is believed to be the predominant causative risk factor in the pathogenesis of BCC. For years, BCC and squamous cell carcinoma (SCC) have been grouped together as “nonmelanoma skin cancer.” However, it seems that there are considerable biologic differences between BCC and SCC, and thus each type of epithelial cancer should be addressed separately. The present review provides an overview of the intriguing etiologic link of BCC with UVR and attempts a comprehensive review of recent epidemiologic and molecular evidence that supports this association.  相似文献   

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The environmental CRMs currently available from NRC Ottawa comprise four natural waters for trace elements, four biological tissues for trace elements and methylmercury, three marine sediments for major and trace elements (one sediment has certified values for butyltins) and one fish tissue for organochlorines (PCBs, dioxins). Although significant effort has been expended to maintain this suite of materials, several new initiatives have also recently been completed or are in progress. The certified value for arsenobetaine in Dogfish Muscle CRM DORM-2 has been established. The certification approaches, as well as the studies to determine extraction efficiency of this organoarsenic compound, are presented. A stability study has been completed for Hg in a natural water sample and plans are underway for production of a CRM. Assessment of micronutrient stability in seawater for the purposes of CRM production is continuing and progress on this initiative is discussed.  相似文献   

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A challenge to the incorporation of 99Tc into a glass matrix is that 99Tc is volatile at vitrification temperatures. Understanding how this volatilization occurs requires knowledge of the multiple chemistries which Tc may take during vitrification. This paper presents an overview of how the localized chemistry of 99Tc has been determined in a series of 99Tc-bearing glasses by chemometric analyses of X-ray absorption near edge spectra (XANES). Linear combination fitting and principal component analysis of the glasses’ XANES spectra suggested that the glasses contained 3–4 chemically distinct Tc environments. The identity of the detected chemistries were pertechnetates, (Tc(VII) as isolated oxyanions, or locally coordinated by Na or K), or isolated Tc(IV) species. The linear combination fitting distribution of local Tc sites agrees with reanalyzed Raman spectra, suggesting that as targeted KTcO4 incorporation increases, a significant ion exchange takes place, and speciation in the glass changes to favor Tc(VII) formation, specifically NaTcO4. Based on the statistical suggestion that not all Tc environments are accounted by the available standards, a new mechanism for the behavior of Tc during vitrification is proposed.  相似文献   

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《Tetrahedron: Asymmetry》2013,24(2-3):viii-ix
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《Tetrahedron letters》2012,53(9):1190
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Kotaro Honda (2/23/1870–2/12/1954) graduated from the Department of Physics, Tokyo Imperial University in 1897. Between 1907 and 1911, he stayed in Europe, and spent the majority of his time at Göttingen University to study physical metallurgy under Professor Gustav Tammann. In 1911, he returned to Japan and was nominated professor of physics at Tohoku Imperial University, Sendai. An university-affiliated institute for research on iron and steel was established on a permanent basis in 1919, and the institute developed to the Research Institute for Iron, Steel, and Other Metals (RIISOM, KINKEN in Japanese) in 1922. Professor Honda served as the Director of the Institute until 1933. The RIISOM was reorganized as a national collaborative research institute named Institute for Materials Research in 2001. Professor Honda and his colleagues achieved distinguished research works of physical metallurgy, in which thermoanalytical techniques such as differential thermal analysis (DTA), thermodilatometry and thermomagnetometry were utilized effectively. Professor Honda also played an important role in the field of thermogravimetry (TG) by means of the first development of the thermobalance. In the present paper, Honda’s original thermobalance, various modifications carried out by his school, the commercialized Honda’s thermobalance and other related matters are briefly summarized.  相似文献   

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Editor’s note     
Journal of Solid State Electrochemistry -  相似文献   

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《Polyhedron》2004,23(1):xiii
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Little information is yet available on the economic viability of the production of bio-based bulk chemicals and intermediates from white biotechnology (WB). This paper details a methodology to systematically evaluate the techno-economic prospects of present and future production routes of bio-based bulk chemicals produced with WB. Current and future technology routes are evaluated for 15 products assuming prices of fermentable sugar between 70 euro/t and 400 euro/t and crude oil prices of US $25/barrel and US $50/barrel. The results are compared to current technology routes of petrochemical equivalents. For current state-of-the-art WB processes and a crude oil price of US $25/barrel, WB-based ethanol, 1,3-propanediol, polytrimethylene terephthalate and succinic acid are economically viable. Only three WB products are economically not viable for future technology: acetic acid, ethylene and PLA. Future-technology ethylene and PLA become economically viable for a higher crude oil price (US $50/barrel). Production costs plus profits of WB products decrease by 20-50% when changing from current to future technology for a crude oil price of US $25 per barrel and across all sugar prices. Technological progress in WB can thus contribute significantly to improved economic viability of WB products. A large-scale introduction of WB-based production of economically viable bulk chemicals would therefore be desirable if the environmental impacts are smaller than those of current petrochemical production routes.  相似文献   

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