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Ecole doctorale Sciences, technologies, santé (Reims, Marne)

Overview
Works: 309 works in 309 publications in 1 language and 309 library holdings
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Most widely held works by technologies, santé (Reims, Marne) Ecole doctorale Sciences
Etude des méthodes d'ordonnancement sur les réseaux de capteurs sans fil. by Bandar Alghamdi( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

The Wireless Body Area Network (WBAN) is the most critical field when considering Wireless Sensor Networks (WSN). It must be a self-organizing network architecture, meaning that it should be able to efficiently manage all network architecture requirements. The WBAN usually contains at least two or more body sensors. Each body sensor sends packets to or receives packets from the Personal Area Network Coordinator (PANC). The PANC is responsible for scheduling its child nodes' tasks. Scheduling tasks in the WBAN requires a dynamic and an adaptive process in order to handle cases of emergency that can occur with a given patient. To improve the most important parameters of a WBAN, such as quality link, response time, throughput, the duty-cycle, and packet delivery, we propose three scheduling processes: the semi-dynamic, dynamic, and priority-based dynamic scheduling approaches.In this thesis, we propose three task scheduling techniques, Semi-Dynamic Scheduling (SDS), Efficient Dynamic Scheduling (EDS) and High Priority Scheduling (HPS) approaches. Moreover, a comprehensive study has been performed for the WBAN platforms by classifying and evaluating them. We also investigate the mobility model for the WBANs by designing an architecture that describe this model. In addition, we detail a diagnosis procedure by using classification methods in order to solve very sensitive epidemic diseases. Then, our proposals have been validated using two techniques to check out the feasibility of our proposals. These techniques are simulation scenarios using the well-known network simulator OPNET and real implementations over TelosB motes under the TinyOS system
Etude des mécanismes épigénétiques associés au phénomène de résistance aux glucocorticoïdes : implication dans la régulation de l'expression de la MMP-9 by Marwa Hentati( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

L'utilisation chronique des glucocorticoïdes conduit généralement au développement d'une résistance aux glucocorticoïdes impliquant une modulation de l'expression de gènes impliqués dans l'inflammation ou la progression tumorale comme celui codant la MMP-9. L'expression de la MMP-9 est régulée par des mécanismes épigénétiques notamment l'acétylation des histones gouvernée par la balance HDAC/HAT (histone deacetyltransferase/histone acetyltransferase) et les micro-ARNs (miRs), mécanismes également impliqués dans les phénomènes de cortico-résistance. Cependant, les altérations épigénétiques survenant suite à un traitement chronique aux glucocorticoïdes et leurs répercutions sur l'expression de la MMP-9 ne sont pas encore clairement élucidés. L'objectif de notre étude consiste donc à déterminer le rôle des mécanismes épigénétiques dans le phénomène de résistance aux glucocorticoïdes à travers leur implication dans la régulation de l'expression de la MMP-9. Nous avons montré que l'exposition chronique aux glucocorticoïdes a perturbé, à la fois, la balance HDAC/HAT (favorisant une hyperacétylation des histones) et l'expression des miRs conduisant ainsi à une surexpression de la MMP-9. De plus, nous avons montré qu'en inhibant les HDACs par le MS-275 amplifiant ainsi le phénomène d'hyperacétylation des histones, le profil d'expression des miRs a été davantage perturbé, une perturbation qui s'est répercuté sur l'expression et la sécrétion de la MMP-9. En conclusion, nous avons montré que l'acétylation des histones et la modulation de l'expression des miRs pourraient agir en harmonie pour contrôler l'expression de la MMP-9 dans un contexte de résistance aux glucocorticoïdes
Conception et réalisation de cellules photoacoustiques miniaturisées pour la détection de traces de gaz by Justin Rouxel( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

Photoacoustic cells are optical sensors based on the absorption of photons by gas molecules. The pressure wave created by gas relaxation is proportional to the trace gas concentration. Furthermore the photoacoustic signal is inversely proportional to the cell volume. Thus cell miniaturization enables performances improvements. This work consists in designing, realizing and characterizing miniaturized photoacoustic cells, based on the differential Helmholtz resonator (DHR) principle. In a first phase, modeling by the finite element method of millimeter scale cells has shown that the miniaturization of this type of resonator should effectively improve the detection limit. Thus, the ambitious realization of a DHR cell on silicon by the use of microelectronic techniques has been attempted. However, this extreme miniaturization direction encountered design and fabrication difficulties which made the produced devices unusable. To overcome these difficulties, a miniaturization alternative, at the centimeter scale, using commercial MEMS microphones, has been carried out. Three cells have been built by different methods and have been tested for methane detection. The last cell generation can detect around 100 ppb of methane with a commercial interband cascade laser at 3.357 µm of wavelength. Finally, to anticipate the next cell generation fabrication, a geometry optimization has been performed by simulation. This optimization shows that a 43 % signal improvement, compared to the most performant cell already built
Polysaccharides et Lignines Modifiés par Extrusion Réactive. by Romain Milotskyi( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

The project involves developing new chemical modifications methodologies using the ecologically compatible and intensive characteristics of reactive extrusion applied to polymers from biomass. With the prospect of worldwide exhaustion of oil supply, the use of renewable natural polymers as potential substitution candidates for oil based application polymers appears as a sustainable alternative. Natural polymers possess physicochemical properties in the native state, which limit their use in many industrial sectors. Even limited chemical modifications radically change the properties of these macromolecular entities. Chemical modifications commonly performed at industrial level in solution or in batches are often very laborious to implement, control, and in addition suffer from energy and environmental cost problems (co-products, use of reagents posing problems). The project aims at studying and developing the composition parameters (polymers, plasticizers, reagents ...), and secondly examining the operating conditions of the chemical modification carried out in an extruder: hydration rate, pressure and temperature kinetics and other parameters with reactions of specific modifications to meet the requirements of industrial applications. Three families of biopolymers of interest to large sectors of biorefineries will be considered: starch and maltodextrins, thermoplastic lignin and cellulosic derivatives
Proposition d'une méthodologie d'intégration des connaissances métiers dans l'interface homme-machine des applications dédiées à la recherche d'information. by Anthony Subasic( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

Our goal is to develop a methodology to analyse, to implement and to evaluate user-trade oriented information retrieval applications.The first chapter begins with a state of the art about information retrieval models. It presents human computer interaction of informatiion retrieval systems. It helps to understand that user trade context has to be dealt of in information retrieval model and especially during the design of dedicated applications.The second chapter is the core of our methodology to analyse, to implement and to evaluate user-trade oriented information retrieval applications. This methodology is called AROM. The chapter explains how to take into account user trade context by integrating an ontology in the dedicated system. The AROM methodoly is compared with an existing system in order to its validation.The third chapter validates the AROM methodology during the design of two industrial case studies. The first case study has been designed during the first steps of the design of the AROM methodology. It helped us understand which concepts were necessary to our methodology. Thanks to our methodology, the second case study has an innovative interface through a user trade oriented information retrieval tool
Etude des propriétés de transport du CO2 et de l'éthanol en solution hydroalcoolique par dynamique moléculaire classique : Application aux vins de Champagne. by Alexandre Perret( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

The work presented in this manuscript is devoted to the study of the diffusion of dissolved carbon dioxide and ethanol in a hydroalcoholic solution model representing Champagne wines. The first part of this work deals with the different formalisms of molecular diffusion, as well as theoretical and experimental methods used to account for this phenomenon of transport. Particular attention is paid to the classical force field molecular dynamics that is used in this work with the GROMACS software. This theoretical approach provides a new perspective in research on champagne and particularly on the role of each of the main species in CO2 diffusion. NMR spectroscopy, and an experimental method based on the study of the bubbles growth rate, were also used. In the second part, the theoretical and experimental results are presented and compared with each other to validate the protocol of molecular dynamics simulations. The viscosities of the model solution and of the champagne, as well as the hydrodynamic radii of CO2 and ethanol, are also investigated. The last part of the manuscript focuses on the partnership with the Bull company and the study of the GROMACS software performance. The expertise of and the tools developed by the Bull company are used to study the scalability and the parallel behavior of GROMACS for modeling champagne
Suivi par télédétection multi-source du bassin endoréique du Chott El Djérid (Tunisie) entre 1985 et 2015 by Khairat Abbas( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

La dépression du Chott El Djérid constitue l'un des bassins endoréiques salins les plus importants dans le monde. Au cours du stade d'inondation, le Chott est rempli par deux lacs temporaires localisés au centre du Chott et séparés par la digue-route P16, suite à des pluies abondantes et/ou la remontée de la nappe souterraine. Les variations spatiales du cycle inondation-assèchement sont marquées par une inondation et un assèchement plus rapide dans la partie au sud de la digue-route que celle au nord. Les variations temporelles sont illustrées par la comparaison de ce cycle entre les inondations de l'hiver 2009, du printemps 2007 et de juin 2014 au cours de la période sèche. Au cours de ce cycle entre avril et août 2007, les valeurs de réflectance ont varié de 2 à 37 % au sud de la digue-route et de 2 à 31 % au nord. Elles sont donc plus élevées et leur augmentation est en moyenne plus rapide au sud de la digue-route qu'au nord. Les processus évaporitiques du Chott sont contrôlés par les processus hydriques et éoliens. Après l'assèchement du lac, les croûtes évaporitiques du Chott comprennent un assemblage de minéraux dominé par la halite sur la marge méridionale de la digue-route et par le gypse au nord de celle-ci. Les croûtes gypseuses apparaissent dynamiques dans l'espace et le temps et sont distribuées plus largement que les croûtes de halite. Les données LSR (Landsat Surface Reflectance) ont fourni des indications sur la minéralogie des évaporites, même si elles sont à moyenne résolution spectrale. L'étude a apporté également des informations sur les autres unités de paysage telles que les aïoun, la bordure sableuse, etc
Élaboration de nouveaux revêtements prothétiques phosphocalciques par électrodéposition. : caractérisation physico-chimique et structurale by Richard Drevet( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

This manuscript presents an innovative process to produce prosthetic calcium phosphate coatings: electrodeposition. An original protocol is developed, combining pulsed electrodeposition current mode and the incorporation of hydrogen peroxide (H2O2) into the electrolytic solution. This protocol leads to homogeneous and compact calcium phosphate coatings whose chemical composition is controlled. They may consist of a calcium-deficient hydroxyapatite with a variable deficit or of a stoichiometric hydroxyapatite. The morphology of the coatings is observed by SEM and STEM, and their chemical composition is studied by X-ray microanalysis and by a standardized method based on XRD, determining the characteristic Ca/P atomic ratio of these coatings. The study of the thermal behavior of the elaborated samples is performed in order to determine the optimal treatment temperature to obtain a sufficient value of the calcium phosphate coating adhesion onto the metallic substrate. Despite the limitation of this temperature to 550°C when the treatment is carried out in air, the measurement of the coating adhesion to the substrate leads to a value of 16.5 MPa that corresponds to the standardized criteria for the surgical implants. Furthermore, the bioactivity of the elaborated coatings is evaluated in a physiological environment by studying firstly their corrosion behavior using the Tafel representation of the polarization curves and the electrochemical impedance spectroscopy, and secondly by studying the dissolution precipitation reactions that occur during a prolonged immersion. The formation of a “bonelike” apatite layer on the surface of the electrodeposited coating is then observed. The elaboration protocol developed allows the modulation of these behaviors in physiological medium. Finally, the flexibility of the electrodeposition process is used to uniformly incorporate strontium in the calcium phosphate coating that is an active agent whose release in physiological medium can be modulated. A structural study is performed to observe that the incorporation of this element in the coating modifies the proportion of the phases that compose the coating after a suitable thermal treatment. The phase proportion and the uniform distribution of the strontium are also observed at the submicron scale by EELS
Implication de la protéine Zonula Ocludens-2 (ZO-2) dans le processus d'invasion tumorale by Emilie Luczka( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

Lors de l'invasion tumorale, les cellules épithéliales tumorales acquièrent des propriétésmigratoires et invasives impliquant des modifications phénotypiques importantes. Parmi ceschangements, on observe notamment une réorganisation ou une perte des complexes d'adhérenceintercellulaire et une acquisition de la capacité à dégrader la matrice extracellulaire à travers uneaugmentation d'expression des métalloprotéinases matricielles (MMPs). Dans cette étude, nous noussommes plus particulièrement intéressés aux jonctions serrées qui sont constituées de protéinestransmembranaires (occludine, claudines) liées au cytosquelette d'actine par des protéinescytoplasmiques sous-membranaires incluant les Zonula Occludens (ZO-1, -2 et -3). Parmi cesmolécules, nous avons évalué le rôle potentiel de ZO-2 dans l'acquisition de propriétés invasives parles cellules tumorales. In vivo, nous avons montré une diminution d'expression des ZOs dans lescancers broncho-pulmonaires avec une localisation cytoplasmique préférentielle. De plus, in vitro, lalocalisation des ZOs varie en fonction du potentiel invasif des cellules tumorales et leur réorganisationest corrélée à la migration cellulaire. Nous démontrons également que l'inhibition de ZO-2 augmenteles capacités invasives de cellules tumorales invasives et s'accompagne d'une augmentationd'expression des MMP-2 et -14 et du facteur de transcription ZEB-2. Ces résultats suggèrent que ZO-2, composant structural des complexes d'adhérence intercellulaire dans les cellules différenciées,pourrait jouer un rôle clé dans le processus d'invasion tumorale. Sa capacité à transiter de lamembrane au cytoplasme et/ou au noyau lui permettrait d'agir comme une molécule de signalisationen régulant la transcription de gènes. Les données obtenues démontrent un rôle anti-invasif de ZO-2
Contribution au diagnostic des Systèmes à Evénements Discrets par modèles temporels et distributions de probabilité. by Noureddine Malki( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

The work presented in this thesis represents a contribution to the problem of diagnosis in discrete event systems (DES). The objective of our work consists in a proposition for a diagnostic approach by exploiting the temporal aspect which characterizing the occurrence of events. For this, the system is modeled by temporal graphs belonging to the timed automata formwork. The approach is designed according to the decentralized architecture to avoid any combinatorial explosion in the construction of the models. It has allowed the detection and isolation of abrupt faults occurring on equipment by combining the enablement conditions of events and the Boolean functions for the non-occurrence of events.Secondly, gradual faults coming from the process its self are considerate. For this, time constraints expressing the dates of occurrence of events in the Templates and Chronicles are modeled by probability distributions (PDs). These are used to characterize normal, degraded or failed functioning of each subsystem with a degree of certainty. Identification of this functioning mode is represented by the value of a degradation indicator
Interactions entre les granulats de chanvre et les liants à base de ciment et de chaux : Mécanismes de la prise et propriétés des interfaces formées dans les agrobétons. by Youen Diquelou( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

The hemp concretes, combine a plant aggregate, called “shiv” with a mineral binder. They are insulating materials particularly suited to face the new environmental problems of the building sector. However, their development is hampered by the occasional implementation problems and their relatively low mechanical properties that could result from complex interactions between the shiv and the binder. In this context, the objective of the presented work was to clarify the nature of these interactions and to identify the mechanisms by which they can impact the setting of the binder and the final properties of the material. To do so, the evolution of mixtures of the initial components (shiv and binders) differing by their nature was studied by biochemical, spectroscopic, physical chemistry and mechanical techniques. This multi-scale approach enabled us to highlight the powerful set retarding action of shiv-extractable products on hydraulic binders. This delay can even lead to a total failure of the binder setting when this one is coupled to simultaneous degradation of the hemp aggregate, migration of the formed products in the matrix and water evaporation. Finally, it has been demonstrated that the characteristics of the shiv (chemical composition), the nature of the binder (pure cement or lime added), and the curing conditions (presence or absence of CO2) represent factors that may modulate the deleterious effects on the setting and the mechanical properties of the formed material. They hence constitute potential parameters for the optimization of hemp concretes
Etude expérimentale et numérique de l'influence des interactions contenant/contenu sur le comportement élasto-viscoplastique d'emballages en polyéthylène haute densité by Ngoc Giang Tran( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

Dans le cadre de cette thèse, nous avons étudié l'interaction contenant-contenu entre un emballage à base de polyéthylène haute densité (PEHD) et l'acétate d'amyle considéré comme diffusant. Nous nous sommes plus précisément intéressés à l'impact du phénomène de sorption et de diffusion sur les propriétés mécaniques en sollicitations statique et de fluage de flacons en PEHD à différents stades du vieillissement physique. Une campagne expérimentale a été menée et une base de données issue d'essais menés sur des éprouvettes prélevées sur des flacons ainsi que d'essais de structure réalisés sur des flacons a été constituée. L'analyse des différents résultats expérimentaux a notamment mis en évidence la nature fickienne du phénomène de diffusion et la chute de la résistance à la compression verticale des flacons. Nous avons ensuite proposé la modélisation du comportement mécanique du PEHD avec prise en compte du transfert de masse induit par le phénomène de diffusion. Des modèles élastoviscoplastique et de fluage ont été proposés et implémentés dans le code de calcul en éléments finis ABAQUS. Les paramètres de ces modèles ont été identifiés à partir de sollicitations simples par la résolution d'un problème d'optimisation, et les modèles ainsi identifiés ont été validés par la simulation numérique d'essais réalisés sur des flacons. Les résultats numériques obtenus sont en très bonne adéquation avec les mesures expérimentales
Impact de l'infection à Staphylococcus aureus sur le microenvironnement osseux by Jérôme Josse( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Staphylococcus aureus-related bone and joint infections are common diseases whose consequences can range from simple cell damage to delayed bone repair or excessive inflammatory response. To study this phenomenon, we have developed two models of in vitro infection with Staphylococcus aureus and primary bone-forming cells derived from human surgical explants. These cells have been previously cultured in a standard medium or osteogenic medium to obtain two populations at different stages of maturation. The study of Staphylococcus aureus internalization, cell death and production of inflammatory mediators in these 2 populations allowed us to establish whether the impact of Staphylococcus aureus varied depending on cell maturation. We also studied the impact of Staphylococcus aureus on mesenchymal stem cells derived from umbilical cord. In case of bone regeneration in infected site, mesenchymal stem cells may have to interact with Staphylococcus aureus. Therefore, we characterized the ability of these cells to internalize Staphylococcus aureus, to survive against the infection and to produce inflammatory mediators in our in vitro model of acute infection. This project allowed us to validate our in vitro infection models and to characterize the impact of Staphylococcus aureus on different cells in the bone microenvironment, providing new approaches for the development of antibacterial strategies and bone tissue engineering
Thermométrie par photoluminescence, application en micro/nanothermique by Gary Degliame( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

This PhD work focuses on the study of microcrystals photoluminescence in order to design a hybrid probe allowing micro/nano-scales measurements of a sample's temperature and the thermal conductivity. Thus, a Wollaston thermoresistive probe used in thermal microscopy (SThM), was coupled to an Erbium doped microcrystal of Cd0.7Sr0.3F2 (4% Er3+), whose emission spectrum is sensitive to the temperature.At first, for its applications in thermometry, the optical properties of the bulk crystal have been studied. We worked on the interpretation of its luminescence spectrum obtained by up-conversion using a laser diode centered at 655 nm and 4mW. Then, we proposed three methods to determine the fluorescence intensities to access this temperature via the RIF (Fluorescence Intensity Ratio) technique. We have shown that it is possible to determine its temperature using the Stark sub-levels of the thermalized levels emissions intensities.Furthermore, we studied the temperature behavior of the microcrystals individually fixed at the end of thermoresistive probes. The experimental results made it possible to deduce the optimal size of the microcrystal and the most adapted intensity determination method for nano/microthermometry.After validating our microcrystal temperature approach, we focused on the principle of temperature imaging from photoluminescence spectra. We present an application on a microsystem composed of wires with a diameter of 350nm covered by a SiO2 thin film
Enrichissement des Modèles de Classification de Textes Représentés par des Concepts by Jean-Charles Risch( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

Most of text-classification methods use the ``bag of words” paradigm to represent texts. However Bloahdom and Hortho have identified four limits to this representation: (1) some words are polysemics, (2) others can be synonyms and yet differentiated in the analysis, (3) some words are strongly semantically linked without being taken into account in the representation as such and (4) certain words lose their meaning if they are extracted from their nominal group. To overcome these problems, some methods no longer represent texts with words but with concepts extracted from a domain ontology (Bag of Concept), integrating the notion of meaning into the model. Models integrating the bag of concepts remain less used because of the unsatisfactory results, thus several methods have been proposed to enrich text features using new concepts extracted from knowledge bases. My work follows these approaches by proposing a model-enrichment step using a domain ontology, I proposed two measures to estimate to belong to the categories of these new concepts. Using the naive Bayes classifier algorithm, I tested and compared my contributions on the Ohsumed corpus using the domain ontology ``Disease Ontology”. The satisfactory results led me to analyse more precisely the role of semantic relations in the enrichment step. These new works have been the subject of a second experiment in which we evaluate the contributions of the hierarchical relations of hypernymy and hyponymy
Les allylalanes chiraux en synthèse asymétrique. De la synthèse diastéréosélective au dédoublement cinétique promu par le camphre by Michael Coffinet( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

This thesis deals with the use of chiral allylmetals, allylalanes and allylzincs, in asymmetric synthesis. Strategies adapted to the intrinsic configurational stability of these two species have been developed and applied to the synthesis of enantio-enriched homoallylic alcohols and amines.The first part of this manuscript is devoted to the generation of cycloalkylen-1-yl-zinc from the corresponding alanes via a titanium-catalyzed hydroalumination of conjugated dienes / transmetallation sequence. These allylzines, involved in the allylmetallation of non-racemic imines, provided the corresponding homoallylamines with good diastereoselectivity according to a dynamic kinetic resolution process.The first part of this memory discusses the generation of cycloalkylen-1-ylzincs from the corresponding alanes via a titanium-catalysed hydroalumination of cyclic conjugated dienes/transmetallation sequence. These allylzincs, involved in the allylmetallation of non-racemic imines, provided homoallylic amines with good diastereoselectivity according to a dynamic kinetic resolution process.The second part of this work aims at studying the influence of transmetallation co-products on the stereochemical course of the imine allylation reaction. The alternative use of allylzirconiums, which delivers a inert Lewis acid, was proven to benefit to the streoselectivity of the imine allylation.The last part of this work concerns the direct use of chiral allylalanes. Based on the configuration stability of these alanes, a kinetic resolution of the two enantiomers, using camphor as a "chiral trap", allowed to enrich the reaction medium with an enantiomer. The subsequent addition of prochiral electrophiles gives access to enantio-enriched homoallylic alcohols and amines
Etude des propriétés anti-tumorales in vitro de stilbènes issus de suspension cellulaire de vigne (Vitis labrusca) by Laetitia Nivelle( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

Resveratrol, a natural stilbene found in the grapevine, exhibits pleiotropic antitumor activities. This molecule has been shown to inhibit the cancerogenesis processes at different levels. Its impact in tumor growth, in vitro, is generally associate with a disruption in cell cycle and an apoptosis induction. Various resveratrol derivatives appear also efficient to modulate tumor growth. We have studied, during this work, biological activities of stilbenes produced by grapevine cell cutures. Our results show a decrease in melanoma human growth, in vitro, for bioproduced resveratrol oligomers as well as resveratrol itself. Our experiments underline distinct effects between resveratrol and its derivatives. Indeed, all compounds disrupt cell cycle, but resveratrol induces S-phase arrest while resveratrol oligomers failed to induce a clearly phase arrest. Moreover, only resveratrol oligomers only have the ability to counteract invasive and migratory properties of melanoma cells. Finally, experiments performed in normal human fibroblasts study show that resveratrol oligomers present a similar potential to reduce viability of cancer as well as normal cells contrary to resveratrol which is less efficient in normal cells. However the cytotoxicity of resveratrol and its derivatives is significantly reduced on normal cells
Mesure de la température par photoluminescence : application en microscopie thermique à sonde locale. by Adel Sayoud( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

The work presented in this thesis is a contribution to progress towards more quantitative thermal measurements. This is to measure the temperature by RIF technique green emission. The work in this thesis is divided into three stages. Initially we measured the temperature rise of a massive crystal Sr0.3Cd0.7F2 codoped Er3 + / Yb3 + 0.3 mm thick. The heat induced by the excitation of Yb3 + ions to 974.4 nm was measured at a distance (d) at the edge of crystal, the green emission of the Er3 + ions excited by red laser (652 nm) at the edge of the crystal.The second step was designed to measure the temperature of the heating of the same previous crystal, but in microscopic dimensions. These fluorescent microparticles were attached to the end of a thermal probe Wollaston. The temperature rise of the microparticles is by a red laser excitation at 652 nm or by Joule effect through an electric current in the probe thermorésistive.The third step was the main aim of measuring the temperature using a micrometric scale atomic force microscope (AFM) on which is mounted at its end provided with one of a fluorescent microparticle thermorésistive probe Sr0.3Cd0.7F2 codoped Er 3 + / Yb 3 + 15 microns used as a temperature sensor. The technique is based on the change in fluorescence intensity of the microparticle in contact with a hot surface. This new technique allowed us to obtain a map image of the temperature of a microsystem consisting of submicron heating lines, heated by Joule effect
VIPEBCO - Rôle du vieillissement et des peptides d'élastine sur la réponse immune adaptative au cours de la BPCO by Alexandre Pierre( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

La BPCO est une affection de l'appareil respiratoire associée à une réponse inflammatoire chronique. La BPCO associe une bronchite chronique, avec obstruction des voies aériennes, et un emphysème caractérisé par la destruction du parenchyme pulmonaire. Si l'exposition au tabac est le facteur de risque principal de la BPCO, plusieurs observations cliniques sont en faveur du rôle du vieillissement dans la pathogénèse de la maladie. La dégradation des fibres élastiques du poumon en peptides solubles d'élastine (PE) est une caractéristique constante de la BPCO, et le vieillissement physiologique du poumon est associé à une augmentation de son activité élastinolytique. Nous avons montré dans un travail précédent que l'instillation de PE à des souris induit un emphysème aigu. La relation existant entre l'élastolyse et le vieillissement conforte l'hypothèse que le vieillissement pourrait représenter un risque majeur de la BPCO par le biais de production de PE. Le travail de thèse présenté dans ce manuscrit a porté sur l'étude comparative des paramètres histologiques, inflammatoires et immunitaires liés à l'emphysème induit par les PE dans des souris jeunes et des souris âgées. Les résultats obtenus montrent que l'emphysème est d'apparition plus précoce chez les souris âgées et que cette précocité s'accompagne d'une augmentation de la production de PE et de clones T CD28- mémoires spécifiques des PE et du processus d'immunosénescence
Elaboration et caractérisation de matériaux issus des agro-ressources. Applications en emballage souple by Sophie Risse( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

This PhD thesis deals with the elaboration of flexible tubes for cosmetics, made from agro-resources. Nowadays, flexible tubes for cosmetic applications are made with PE for its good mechanical properties and its very low water vapor permeability. What can limit the development of polyesters made from agro-resources in the packaging area is precisely their bad water vapor barrier properties. Now incorporating nanoclays in a polymer matrix is one of the most promising techniques to decrease the permeability of the matrix.Then PLA/PBS/clay and PHA/PBS/clay were studied. Two organoclays, with two different organic modifiers, were used: the Dellite® 67G (D67G) and the Cloisite® 30B (Cl30B). The nanocomposites were prepared by melt mixing in a laboratory scale twin screw extruder. XRD and rheological measurements indicated a mixed partial intercalated and exfoliated structure. The exfoliation level was shown to increase with Cl30B content but had an optimum using D67G. The Young's modulus increased when increasing clay content and the presence of residual large clay aggregates leads to brittle blends for the high clay content. Even if the incorporation of Cl30B enhances significantly the water vapor barrier properties of PLA/PBS and PHA/PLA blends (up to 50%), it could not yet concurrence PE. An accelerated ageing test (specific for PE tubes) on our tubes filled with cream showed very important weight loss (16%) compared to the PE tubes (<1%)
 
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ED 358

EDSTS

Université de Reims Champagne-Ardenne. Ecole doctorale Sciences, technologies, santé

Université de Reims Champagne-Ardenne. ED 358

Université de Reims Champagne-Ardenne. EDSTS

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French (20)