1,737 research outputs found

    Optimisation de substituts de tissus urologiques entiÚrement humains reconstruits par génie tissulaire avec les cellules isolées du tissu adipeux

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    La vessie est un organe qui est sujet Ă  diverses maladies ou malformations nĂ©cessitant parfois des chirurgies pour remĂ©dier aux problĂšmes. Ces chirurgies ont souvent pour but d’augmenter le volume utile de la vessie pour protĂ©ger les reins. Plusieurs substituts de tissu urologique existent, mais aucun ne possĂšde les qualitĂ©s suffisantes pour rĂ©pondre aux conditions physiologiques auxquelles ces tissus seront soumis. L’objectif du projet consiste Ă  crĂ©er un substitut entiĂšrement humain par la mĂ©thode d’auto-assemblage et Ă  caractĂ©riser ce tissu. De plus, la possibilitĂ© de produire ce substitut Ă  l’aide des cellules stromales isolĂ©es du tissu adipeux a Ă©tĂ© Ă©tudiĂ©e. Le potentiel de ces cellules pourrait permettre d’optimiser la greffe de ces substituts. Nos rĂ©sultats montrent qu’il est possible de reconstruire un substitut entiĂšrement humain par la mĂ©thode d’auto-assemblage et que les cellules stromales isolĂ©es du tissu adipeux peuvent ĂȘtre utilisĂ©es pour participer Ă  la reconstruction d’un substitut vĂ©sical

    Quantum metamaterials in the microwave and optical ranges

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    Quantum metamaterials generalize the concept of metamaterials (artificial optical media) to the case when their optical properties are determined by the interplay of quantum effects in the constituent 'artificial atoms' with the electromagnetic field modes in the system. The theoretical investigation of these structures demonstrated that a number of new effects (such as quantum birefringence, strongly nonclassical states of light, etc) are to be expected, prompting the efforts on their fabrication and experimental investigation. Here we provide a summary of the principal features of quantum metamaterials and review the current state of research in this quickly developing field, which bridges quantum optics, quantum condensed matter theory and quantum information processing

    Pyqcm: An open-source Python library for quantum cluster methods

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    Pyqcm is a Python/C++ library that implements a few quantum cluster methods with an exact diagonalization impurity solver. Quantum cluster methods are used in the study of strongly correlated electrons to provide an approximate solution to Hubbard-like models. The methods covered by this library are Cluster Perturbation Theory (CPT), the Variational Cluster Approach (VCA) and Cellular (or Cluster) Dynamical Mean Field Theory (CDMFT). The impurity solver (the technique used to compute the cluster's interacting Green function) is exact diagonalization from sparse matrices, using the Lanczos algorithm and variants thereof. The core library is written in C++ for performance, but the interface is in Python, for ease of use and inter-operability with the numerical Python ecosystem. The library is distributed under the GPL license.Comment: Submission to SciPost. arXiv admin note: substantial text overlap with arXiv:0806.269

    Quantum metamaterials in the microwave and optical ranges

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    Quantum metamaterials generalize the concept of metamaterials (artificial optical media) to the case when their optical properties are determined by the interplay of quantum effects in the constituent 'artificial atoms' with the electromagnetic field modes in the system. The theoretical investigation of these structures demonstrated that a number of new effects (such as quantum birefringence, strongly nonclassical states of light, etc) are to be expected, prompting the efforts on their fabrication and experimental investigation. Here we provide a summary of the principal features of quantum metamaterials and review the current state of research in this quickly developing field, which bridges quantum optics, quantum condensed matter theory and quantum information processing

    Lecture automatique d'un ticket de caisse par vision embarquée sur un téléphone mobile

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    Travaux rĂ©alisĂ©s dans le cadre d'une thĂšse CIFRENational audienceThis work addresses the automatic reading of sale receipts acquired with a smartphone's camera and the extraction of essential informations like the store brands, all the purchased products , their price etc. It is divided into two major tasks : the optical character recognition that is made complex due to the nature of the document often damaged, crumpled or torned and the semantic data analysis to identify purchased product without ambiguity. In this paper, we introduce a solution that enables a "guided" capture on smartphone and a receipt decoding on remote server.L'objectif de ces travaux est de crĂ©er un systĂšme capable, Ă  partir d'une simple vue prise par un smartphone, d'exploiter le contenu d'un ticket de caisse, et d'en extraire des informations telles que le point de vente, les produits ache-tĂ©s, leurs prix etc. On distingue deux Ă©tapes majeures : la reconnaissance optique de caractĂšres sur des tickets qui peuvent ĂȘtre froissĂ©s, dĂ©chirĂ©s... et l'analyse sĂ©mantique afin d'identifier les produits achetĂ©s sans ambiguĂŻtĂ©. Dans ce papier, nous prĂ©sentons une solution qui effectue une acquisition "guidĂ©e" d'une image sur smartphone et une lecture du contenu sur un serveur distant

    Study of overland flow with uncertain infiltration using stochastic tools

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    The saturated hydraulic conductivity is one of the key parameters in the modelling of overland flow water fluxes. In this study, this parameter is defined as a stochastic parameter, idealized as a piecewise constant random field with uniform distribution. This paper aims at investigating the effects of the spatial and temporal scales in uncertainty propagation within overland flow models, and at identifying the localization of the most influential saturated hydraulic conductivity using sensitivity analysis. The results show that the influence of saturated hydraulic conductivity depends on the soil saturation and its spatial localization. For instance, in case of low saturated soils, the most influent parameter is the one located downslope, whereas in case of high saturated soils, the most influent one is either the most infiltrating or the intermediate one. The results indicate where efforts should be concentrate when collecting input parameters to reduce modelling uncertainties

    Speciation Success of Polyploid Plants Closely Relates to the Regulation of Meiotic Recombination

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    Polyploidization is a widespread phenomenon, especially in flowering plants that have all undergone at least one event of whole genome duplication during their evolutionary history. Consequently, a large range of plants, including many of the world’s crops, combines more than two sets of chromosomes originating from the same (autopolyploids) or related species (allopolyploids). Depending on the polyploid formation pathway, different patterns of recombination will be promoted, conditioning the level of heterozygosity. A polyploid population harboring a high level of heterozygosity will produce more genetically diverse progenies. Some of these individuals may show a better adaptability to different ecological niches, increasing their chance for successful establishment through natural selection. Another condition for young polyploids to survive corresponds to the formation of well-balanced gametes, assuring a sufficient level of fertility. In this review, we discuss the consequences of polyploid formation pathways, meiotic behavior and recombination regulation on the speciation success and maintenance of polyploid species

    N-Phenyl-N’-(2-chloroethyl)ureas (CEUs) as potential antineoplastic agents. part 3 : role of carbonyl group

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    n the course of the development of N-phenyl-Nâ€Č-(2-chloroethyl)ureas (CEUs) as potential antineoplastic agents, we investigated the effect of carbonylated substituting chains of the aromatic ring of CEU on their covalent binding to the colchicine-binding site (C-BS). In this study, we found that CEU, 5e, 5f, 8e, and 8f substituted by either a methyl ester or a methyl ketyl group at the ω-position exhibited a significant antiproliferative activity on HT-29, M21, and MCF-7 tumor cells. SDS–PAGE assays and cell cycle analysis confirmed that 5e, 5f, 8e, and 8f covalently bind to the C-BS and arrest the cell division in G2/M phase. Surprisingly, the presence of ω-carboxyl, ω-ethyl esters or ω-amides decreased significantly both the antiproliferative activity and the specificity toward ÎČ-tubulin
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