9 research outputs found

    Fonctionnalisations et caractérisations de surfaces par des films polythiophÚnes et dépÎts de particules composites

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    L objectif de cette thĂšse est de rĂ©aliser des matĂ©riaux composites constituĂ©s d un assemblage de polymĂšres et de particules sur un substrat conducteur. L association de deux Ă©lĂ©ments de nature diffĂ©rente permet alors de confĂ©rer des propriĂ©tĂ©s spĂ©cifiques Ă  ce nouveau matĂ©riau dont les applications potentielles concernent diffĂ©rents secteurs industriels tels que les microtechniques, l optique, l Ă©lectronique Dans un premier temps, la surface de substrats d or Ă  Ă©tĂ© fonctionnalisĂ©e par des films de polymĂšre (polybithiophĂšnes et polytris) [5-(2,2 -bithiophĂšne)] mĂ©thanol), obtenus par Ă©lectropolymĂ©risation. L influence de plusieurs paramĂštres sur la formation des films Ă©lĂ©ctropolymĂ©risĂ©s a Ă©tĂ© Ă©tudiĂ©e : nature et concentration du monomĂšre, composition de la solution (sel de fond), vitesse de formation du film DiffĂ©rentes techniques de caractĂ©risation des films obtenus (microscopies optique et Ă©lectronique, ellipsomĂ©trie spectroscopique, AFM) ont Ă©tĂ© employĂ©es afin de caractĂ©riser la morphologie et l Ă©paisseur de ces films. Le suivi in situ de la formation de films Ă©lectropolymĂ©risĂ©s a Ă©galement Ă©tĂ© Ă©tudiĂ© par rĂ©flectomĂ©trie laser Ă  angle fixe couplĂ©e Ă  la voltamĂ©trie cyclique. Ainsi une corrĂ©lation entre les morphologies des films obtenus et les signaux rĂ©flectomĂ©triques a pu ĂȘtre rĂ©alisĂ©e. Les rĂ©sultats obtenus ont Ă©tĂ© appuyĂ©s par la dĂ©termination des indices de rĂ©fraction et des Ă©paisseurs par ellipsomĂ©trie spectroscopique ainsi que par des mesures d absorbance par spectrophotomĂ©trie UV-Visible des nanoparticules inorganiques (silice) absorbĂ©es sur des microparticules organiques (latex) a Ă©tĂ© rĂ©alisĂ© sur une surface mĂ©tallique non fonctionnalisĂ©e. Les particules de latex de taille micromĂ©trique permettent de contrĂŽler leur transport sur la surface et les particules nanomĂ©triques apportent la fonctionnalitĂ© souhaitĂ©e. Le dĂ©pĂŽt Ă©lectrophorĂ©tique des particules a Ă©tĂ© Ă©tudiĂ© en fonction de diffĂ©rents paramĂštres physico-chimiques (Ph, concentration et nature d additifs organiques, polarisation ) Selon les conditions expĂ©rimentales, le dĂ©pĂŽt des particules composites peut ĂȘtre rĂ©versible ou irrĂ©versible. De plus la dĂ©sorption des nanoparticules est observĂ©e dans certains cas. AprĂšs avoir sĂ©lectionnĂ© les conditions expĂ©rimentales afin d avoir un dĂ©pĂŽt optimal de particules composites (sans dĂ©sorption des nanoparticules), l assemblage des particules composites sur le substrat mĂ©tallique fonctionnalisĂ© par le film de polymĂšre a Ă©tĂ© Ă©tudiĂ©. Lors de leur dĂ©pĂŽt Ă©lectrophorĂ©tique, les particules s absorbent prĂ©fĂ©rentiellement autour des agrĂ©gats de films polymĂšres.The objective of this study was to synthesize composite materials made of polymer and particles on a conductive substrates. The combination of two elements of different nature allowed to obtain specific properties of the new material. This application for composite material are of potential interest to various industrial sectors :micro-engineering, optics, electronics Initially, the surface of gold substrates was functionalized with polymer films (polybithiophene and polytris [5-(2,2 -bithiophĂšne)] mĂ©thanol]), obtained by electropolymerization. The influence of different parameters on the formation of electropolymerized films was studied : the nature and concentration of the monomer, composition of electrolyte, scan rate of film formation Different techniques (optical and scanning electron microscopy, spectroscopic ellipsometry, AFM) were used to characterize the morphology and thickness of these films. The in situ formation of electropolymerized films was also studied, using a fixed angle laser reflectometer coupled with cyclic voltammetry. A correlation between the morphologies of the films and reflectometry signals was achieved. The results obtained were supported by measuring the refractive index and thickness of the films by spectroscopic ellipsometry and absorbance by UV-Visible spectrophotometry. Secondly, the assembly of composites particles, consisting of inorganic nanoparticles (silica) absorbed onto organic microparticles (latex) was performed on a metal surface. Micrometer-sized latex particles allowed to control their transport to the surface and the nanoparticles provided the desired functionality. The electrophoretic deposition of particles was studied as a function of different physicochemical parameters (pH, concentration and nature of organic additives, polarization ). The deposition of the composite particles may be reversible or irreversible, depending on experimental conditions. Furthermore, desorption of nanoparticles is observed in some cases. After selecting the experimental conditions for optimum deposition of composites particles (without desorption of nanoparticles), the assembly of these particles on the functionalized metal substrate by polymer film was studied. During their electrophoretic deposition, the particles absord mainly around clusters of polymer films.BESANCON-BU Sciences Staps (250562103) / SudocSudocFranceF

    CorHAL une voie pour les chercheurs : simplifier le dépÎt des publications pour accroßtre le taux de texte intégral dans HAL

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    International audienceLancĂ© au printemps 2021 et soutenu par le MESRI, corHAL proposera ses services Ă  la fin de l’annĂ©e. PortĂ© par l’Inist et le CCSD, ce projet permet de collecter des mĂ©tadonnĂ©es de publications scientifiques françaises issues de plusieurs rĂ©servoirs. Ces donnĂ©es sont homogĂ©nĂ©isĂ©es et enrichies Ă  l’aide d’alignements. Un repĂ©rage de doublons assure la crĂ©ation de notices unifiĂ©es combinant les informations des diffĂ©rentes sources. GrĂące Ă  un systĂšme d’alertes (mode push ou pull), le service propose au chercheur ses publications absentes de HAL. Ce dernier choisit d’importer automatiquement aucun, un, plusieurs ou tous les textes intĂ©graux de ses publications dans l’archive ouverte nationale.CorHAL, un outil au service du chercheur et de la science ouverte

    Electrodeposition and characterisation of polythiophene films on gold substrates

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    International audienceStar-shaped oligothiophenes are interesting to use in building super-structured materials. We have already used them to improve particle adhesion and assembly onto conductive substrates in an aqueous medium. In this study, electropolymerization of two different monomers, tris(2,2”- dithienyl)methylcarbinol (TMC) and bithiophene (BT), was carried out on gold film, which was deposited by PVD on silicon wafers. The numbers of cycles and the scan rate have been changed to modify the morphology of the deposit. The polymer films were then characterised by cyclic voltammetry, classical microscopy, atomic force microscopy and scanning electronic microscopy. Polytris(2,2”- dithienyl)methylcarbinol (PTMC) film was flatter, thicker and more uniform than polybithiophene (PBT) film. Finally electrophoretic deposition of composite particles has been carried out on PBT and PTMC films

    Metostem : ouvrir les monographies STM !

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    International audienceÉvolution du projet MetoTaxa (laurĂ©at FNSO-2019), destinĂ© Ă  des revues en taxonomie, Metostem (laurĂ©at FNSO-2021) se dĂ©finit comme une chaĂźne de publication adaptĂ©e aux monographies dĂ©diĂ©es aux STM. Ce projet vise Ă  transformer les outils et les mĂ©thodes de production de l'ensemble des collections de monographies, jusqu'alors rĂ©alisĂ©es uniquement en version papier, afin de crĂ©er un modĂšle Ă©conomique double, papier et numĂ©rique. Le fichier XML pivot sera enrichi dans un environnement d'Ă©dition structurĂ©e MĂ©topes spĂ©cifique dotĂ© de dispositifs d'appel Ă  des API vers des catalogues comme Zoobank, CrossRef ou encore GBIF et Treatment Bank avec GoldenGate (outil de la sociĂ©tĂ© Plazi), qui permet de structurer finement les taxons, les matĂ©riels examinĂ©s et les rĂ©fĂ©rences bibliographiques. Metostem intĂ©grera ainsi un maximum de donnĂ©es sĂ©mantisĂ©es et liĂ©es. DĂšs publication de l'imprimĂ©, Metostem permettra la diffusion de versions numĂ©riques augmentĂ©es et dĂ©tachables (ePub et pdf) ainsi qu'un accĂšs freemium de la version HTML.Metostem participera activement Ă  la science ouverte et en conformitĂ© avec les principes « FAIR », en permettant de structurer et dissĂ©miner des contenus et des donnĂ©es issus de la recherche en biodiversitĂ© et Ă©cologie au sens large (inventaires, atlas, registres d'identification...), qui sont pour l'heure insuffisamment utilisĂ©s, faute d'accessibilitĂ© et d'interopĂ©rabilitĂ©.Metostem mutualise les compĂ©tences propres Ă  chaque partenaire : en tant qu'Ă©diteur scientifique en taxonomie, biodiversitĂ© et Ă©cologie, le MusĂ©um est chargĂ© de la crĂ©ation du cahier des charges et la gestion du projet, qui porte sur trois collections pilotes (Faune et flore tropicales, Stratotypes et Patrimoines naturels) ; l'INIST apporte ses compĂ©tences techniques dans la structuration des contenus Ă©ditoriaux et l'export des fichiers finaux pour publication ; MĂ©topes assure l'adaptation technique de l'outil de production selon les spĂ©cifications Ă©laborĂ©es ensemble. Ce projet, commencĂ© en avril 2022, s'achĂšvera en 2023 et pourra ĂȘtre Ă©tendu Ă  d'autres Ă©diteurs institutionnels

    High Risk of Anal and Rectal Cancer in Patients With Anal and/or Perianal Crohn’s Disease

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    International audienceBackground & AimsLittle is known about the magnitude of the risk of anal and rectal cancer in patients with anal and/or perineal Crohn’s disease. We aimed to assess the risk of anal and rectal cancer in patients with Crohn’s perianal disease followed up in the Cancers Et Surrisque AssociĂ© aux Maladies Inflammatoires Intestinales En France (CESAME) cohort.MethodsWe collected data from 19,486 patients with inflammatory bowel disease (IBD) enrolled in the observational CESAME study in France, from May 2004 through June 2005; 14.9% of participants had past or current anal and/or perianal Crohn’s disease. Subjects were followed up for a median time of 35 months (interquartile range, 29–40 mo). To identify risk factors for anal cancer in the total CESAME population, we performed a case-control study in which participants were matched for age and sex.ResultsAmong the total IBD population, 8 patients developed anal cancer and 14 patients developed rectal cancer. In the subgroup of 2911 patients with past or current anal and/or perianal Crohn’s lesions at cohort entry, 2 developed anal squamous-cell carcinoma, 3 developed perianal fistula–related adenocarcinoma, and 6 developed rectal cancer. The corresponding incidence rates were 0.26 per 1000 patient-years for anal squamous-cell carcinoma, 0.38 per 1000 patient-years for perianal fistula–related adenocarcinoma, and 0.77 per 1000 patient-years for rectal cancer. Among the 16,575 patients with ulcerative colitis or Crohn’s disease without anal or perianal lesions, the incidence rate of anal cancer was 0.08 per 1000 patient-years and of rectal cancer was 0.21 per 1000 patient-years. Among factors tested by univariate conditional regression (IBD subtype, disease duration, exposure to immune-suppressive therapy, presence of past or current anal and/or perianal lesions), the presence of past or current anal and/or perianal lesions at cohort entry was the only factor significantly associated with development of anal cancer (odds ratio, 11.2; 95% CI, 1.18-551.51; P = .03).ConclusionsIn an analysis of data from the CESAME cohort in France, patients with anal and/or perianal Crohn’s disease have a high risk of anal cancer, including perianal fistula–related cancer, and a high risk of rectal cancer
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