68 research outputs found

    Raman characterization of human skin aging

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    Skin aging is a complex biological process mixing intrinsic and extrinsic factors, such as sun exposure. At the molecular level, skin aging affects in particular the extracellular matrix proteins. Materials and Methods: Using Raman imaging, which is a nondestructive approach appropriate for studying biological samples, we analyzed how aging modifies the matrix proteins of the papillary and reticular dermis. Biopsies from the buttock and dorsal forearm of volunteers younger than 30 and older than 60 were analyzed in order to identify chronological and photoaging processes. Analyses were performed on skin section, and Raman spectra were acquired separately on the different dermal layers. Results: We observed differences in dermal matrix structure and hydration state with skin aging. Chronological aging alters in particular the collagen of the papillary dermis, while photoaging causes a decrease in collagen stability by altering proline and hydroxyproline residues in the reticular dermis. Moreover, chronological aging alters glycosaminoglycan content in both dermal compartments. Conclusion: Alterations of the papillary and reticular dermal matrix structures during photo-and chronological aging were clearly depicted by Raman spectroscopy

    EMA - A R package for Easy Microarray data analysis

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    <p>Abstract</p> <p>Background</p> <p>The increasing number of methodologies and tools currently available to analyse gene expression microarray data can be confusing for non specialist users.</p> <p>Findings</p> <p>Based on the experience of biostatisticians of Institut Curie, we propose both a clear analysis strategy and a selection of tools to investigate microarray gene expression data. The most usual and relevant existing R functions were discussed, validated and gathered in an easy-to-use R package (EMA) devoted to gene expression microarray analysis. These functions were improved for ease of use, enhanced visualisation and better interpretation of results.</p> <p>Conclusions</p> <p>Strategy and tools proposed in the EMA R package could provide a useful starting point for many microarrays users. EMA is part of Comprehensive R Archive Network and is freely available at <url>http://bioinfo.curie.fr/projects/ema/</url>.</p

    Cimetières et pluralisme : les lieux de sépultures juifs en France.: "L'hospitalité à l'oeuvre : desseins et dérives (Reid Hall, Paris 2004)".

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    Fonds audiovisuel du programme "ESCoM-AAR" (Equipe Sémiotique Cognitive et nouveaux Médias - Archives Audiovisuelles de la Recherche. Paris, France, 2000 - 2016).Colloque consacré à la notion, au sens de l'hospitalité comprise ici comme une pratique sociale qui relève de la vie quotidienne

    High-frequency magnetocaloric modules with heat gates operating with the Peltier effect

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    Magnetic heat pumps, refrigerators and energy conversion prototypes, with an operation based on the magnetocaloric effect, usually show a restriction in their frequency of operation to a few Hertz. In 2010 it was proposed to apply thermal switches to overcome this barrier. In this article thermal switches built with Ni-nanowire Peltier elements are presented and the performance of such elements is discussed on a theoretical and experimental basis. Finally an approximate estimate of the performance of a magnetic refrigerator of the types built up to present is compared to that of a magnetic refrigerator applying nanowire thermal switches
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