Hypovitaminosis D is associated with depression and anxiety in schizophrenia: results from the national FACE-SZ cohort. Running title: hypovitaminosis D, depression and anxiety in schizophrenia

International audienceBackground. Guidelines have been edited for the treatment of schizophrenia (SZ) and bipola

Versatile synthesis of reversible comb-shaped supramolecular polymers

International audienceWe report a modular synthesis method toward precisely defined hydrogen-bonded polyacrylates. Various stickers are built into difunctional ATRP (Atom Transfer Radical Polymerization) initiators, which then allow the formation of polyacrylates with self-complementary stickers in the middle of the chain, the molar mass of which can be tuned within a large range (from 3 to 100 kg mol−1). These self-assembling polymers are characterized by FTIR and SANS in solution, showing that comb-shaped supramolecular polymers with a reversible backbone can be obtained

Situations au travail des personnes homosexuelles exerçant une fonction manuelle, technique ou ouvrière

nrpages: 78status: publishe

Remote analysis using IR glass fibers

International audienc

Recent developments in chemical sensing using infrared glass fibers

International audienceInfrared (IR) optical fibers based on chalcogenides have been investigated to optimize their response when they are used as evanescent wave chemical sensors. The fiber sensing part diameter can be reduced by tapering the fiber during the drawing process or by chemical polishing. The resulting fiber allows the achievement of a detection probe that has been tested in several experimental conditions. Among them, it is verified that these chalcogenide-based fibers are not sensitive to microwave irradiations and give on-line IR spectra from which kinetics and reaction mechanisms inside a microwave oven can be determine

Infrared chalcogen glasses: Chemical polishing and fibre remote spectroscopy

International audienceInorganic vitreous polymers based on the combination of the chalcogen elements Se, Te and As are investigated on account of their unique transparency in the infrared spectral domain leading to applications in night-vision systems as well as in IR remote fibre spectroscopy. An original procedure of chemical polishing using a congruent dissolution process of the glass is developed in order to produce outstanding optical quality surfaces. The same methodology is applied to produce tapered chalcogen glass fibres used as IR evanescent wave chemical sensors. In reducing the fibre diameter by chemical etching, a significant improvement in the sensitivity of the optical sensor operating in the 2 to 12 μm spectral region is observed. This original optical configuration is applied to some in situ chemical or biological analysis

Supramolecular Chemistry for Pressure Sensitive Adhesives ?

International audiencePressure Sensitive Adhesives (PSA) are soft polymer materials which instantly stick on almost any surface. The adhesives properties of these materials are mainly based on their rheological behavior and, thus on the chemical architecture of the polymer chains. Commercial PSAs are usually composed of lightly crosslinked and highly entangled polymer chains, the molecular structure of which is adjusted to get a good peeling and shear resistance (Creton, C. MRS Bulletin, 2003). The specificity of my project is to investigate the rheological and adhesive properties of short polymer chains functionalized by urea groups. The strong hydrogen bonding interactions between these urea moieties increase strongly the dissipative properties upon deformation, while keeping a low viscosity in non polar solvents (Courtois, J. et al, Adv. Funct. Mater., 2010).The viscoelastic and adhesive properties of linear poly(butylacrylate) chains center-functionalized by bis- or tri-urea stickers were systematically studied. The molecular mechanisms, which govern the rheological behavior at small and large deformation, were identified by modifying the chemical structure of the polymer chains in a systematic way. Based on these results, more complex molecular architectures were then synthesized in order to improve the adhesive properties. The promising results from these new systems highlight the high potential of the supramolecular chemistry for the elaboration of new PSAs

Competition Between Steric Hindrance and Hydrogen Bonding in the Formation of Supramolecular Bottle Brush Polymers

International audienceThe formation of supramolecular bottle-brush polymers consisting of a noncovalent backbone assembled through directional hydrogen bonds and of poly(isobutylene) (PIB) side-chains was investigated in cyclohexane by light scattering. Two limiting cases were observed depending on the balance between the favorable formation of hydrogen bonds and the unfavorable stretching of the PIB chains within the supramolecular bottle-brushes, in agreement with a theoretical model developed by Wang et al. On one hand, a bisurea self-assembling unit able to form four cooperative hydrogen bonds per molecule led to relatively short supramolecular bottle-brushes, the length of which could be varied by modifying steric hindrance or by using solvent mixtures. On the other hand, supramolecular bottle-brush polymers exhibiting persistent lengths of more than 300 nm could be obtained by using trisureas that are able to form six hydrogen bonds per molecule. Their easy synthesis and the fact that it is possible to control their self-assembly into long supramolecular bottle-brush polymers make polymer-decorated bisureas and trisureas an attractive alternative to cyclopeptides and shape-persistent rings for the creation of supramolecular nanostructures

Biological tissues infrared analysis by chalcogenide glass optical fiber spectroscopy

International audienc

Atelier transport et énergie

Cours - 86 pages, figures, tableauxLe choix du groupe s'est porté sur un sujet ayant trait au transport, bien qu'aucun d'entre nous n'ait de compétences particulières dans ce domaine. Néanmoins, le thème du transport nous est apparu intéressant, dans la mesure où il nous concerne tous dans notre vie quotidienne. De fait, nous avons décidé de porter notre attention sur un sujet touchant le transport à Paris et après discussion, nous nous sommes accordés sur l'intitulé du sujet suivant : "Quelles alternatives, d'ici 2020, à l'usage individuel de l'automobile à Paris et ses communes limitrophes ?" La définition du sujet étant acquise, nous avons commencé à travailler sur les différentes étapes de l'atelier, énoncées sur notre feuille de route. Nous présenterons, dans ce dossier, les résultats de ces étapes successives, qui ont conduit notre réflexion