110 research outputs found

    Oxidation of cellulose in pressurized carbon dioxide

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    This work presents first results upon oxidation of type II cellulose by nitrogen dioxide dissolved in carbon dioxide at high pressure. This reaction leads to oxidized cellulose, a natural-based bioresorbable fabric used for biomedical applications. The oxidation reaction takes place in a heterogeneous fluid–solid system. Kinetics of oxidation is presented here and effects of operating conditions such as pressure, temperature and initial moisture content of cellulose are investigated. Results are presented in terms of degree of oxidation of cellulose and quality of the final oxidized cellulose, which has been characterized using liquid-state and solid-state 13C NMR. The experimental results show the existence of possible secondary reactions which may lead to oxidized cellulose with insufficient mechanical strength. An attempt is made to evidence and understand the role of CO2 as a solvent in this system. Indeed, although supercritical CO2 appears to be a suitable candidate as a solvent for oxidation reactions, some inhibiting effect on nitrogen dioxide activity are observed in this case

    AD51B in Familial Breast Cancer

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    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk

    Effects of human footprint and biophysical factors on the body-size structure of fished marine species

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    Marine fisheries in coastal ecosystems in many areas of the world have historically removed large-bodied individuals, potentially impairing ecosystem functioning and the long-term sustainability of fish populations. Reporting on size-based indicators that link to food-web structure can contribute to ecosystem-based management, but the application of these indicators over large (cross-ecosystem) geographical scales has been limited to either fisheries-dependent catch data or diver-based methods restricted to shallow waters (<20 m) that can misrepresent the abundance of large-bodied fished species. We obtained data on the body-size structure of 82 recreationally or commercially targeted marine demersal teleosts from 2904 deployments of baited remote underwater stereo-video (stereo-BRUV). Sampling was at up to 50 m depth and covered approximately 10,000 km of the continental shelf of Australia. Seascape relief, water depth, and human gravity (i.e., a proxy of human impacts) were the strongest predictors of the probability of occurrence of large fishes and the abundance of fishes above the minimum legal size of capture. No-take marine reserves had a positive effect on the abundance of fishes above legal size, although the effect varied across species groups. In contrast, sublegal fishes were best predicted by gradients in sea surface temperature (mean and variance). In areas of low human impact, large fishes were about three times more likely to be encountered and fishes of legal size were approximately five times more abundant. For conspicuous species groups with contrasting habitat, environmental, and biogeographic affinities, abundance of legal-size fishes typically declined as human impact increased. Our large-scale quantitative analyses highlight the combined importance of seascape complexity, regions with low human footprint, and no-take marine reserves in protecting large-bodied fishes across a broad range of species and ecosystem configurations.publishedVersio

    Sulphur oxidation by fungi

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    The Oxford Handbook of Industrial Archaeology

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    Representing the first substantial English-language text on industrial archaeology in a decade, this volume comes at a time when the global impact of industrialization is being reassessed in terms of its legacy of climate change, mechanization, urbanization, the forced migration of peoples, particularly enslaved Africans, and labour relations. Critical debates around the beginning of a new geological era - the Anthropocene - have emerged over the last decade. This approach interrogates the widespread exploitation of natural resources that forged industrialization from its early emergence in eighteenth-century northern Europe to its contemporary ubiquity, environmental impacts, and social legacy within our globalized world. Through a broad international and multi-period set of chapters, this volume explores the complex origins, processes, and development of industrialization through its physical remains and human consequences - both the good and the bad. It provides a diverse material framework for understanding our modern world from its industrial origins through its future paths over the third decade of the twenty-first century

    The Oxford Handbook of Industrial Archaeology

    No full text
    Representing the first substantial English-language text on Industrial Archaeology in a decade, this handbook comes at a time when the global impact of industrialization is being re-assessed in terms of its legacy of climate change, mechanization, urbanization, the forced migration of peoples, and labour relations. Critical debates around the beginning of a new geological era - The Anthropocene - have emerged over the last decade. This approach interrogates the widespread exploitation of natural resources that forged industrialization from its early emergence in 18th century northern Europe to its contemporary ubiquity, environmental impacts, and social legacy within our globalized world. Through a broad international and multi-period set of chapters, this volume explores the complex origins, processes, and development of industrialization through both its physical remains and human consequences - both the good and the bad. It provides a diverse material framework for understanding our modern world, from its industrial origins through its future paths in the 21st century.</p
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