Catalytic Activity of Maghnite-H+ in the Synthesis of Polyphenylmethylsiloxane under Mild and Solvent-free Conditions

In this study, a new and easy strategy was discussed for the purpose of synthesizing of a polymer of phenylmethylcyclosiloxane type (PPMS). The cationic ring opening polymerization of triphenyltrimethylcyclotrisiloxane (D3Ph,Me) was initiated by a solid, efficient and environmentally-friendly catalyst called Maghnite-H+. Maghnite-H+ is a natural clay composed essentially of montmorillonite, it is activated with an acid treatment by replacing the interlayer ions by protons, that results to the increase of the basal space, this may be confirmed by XRD analysis. The reaction was carried out without solvent at different temperatures and for different periods of time, using also several catalyst contents. Subsequently, the operating conditions were opted in order to obtain a maximum yield of the linear polymer and a high average molecular mass as well. The structure of polymers obtained was confirmed by IR analysis. 1H NMR and 13C NMR analyzes were used to follow the crosslinking of polymer chains over time. The thermal behavior was investigated by DSC analysis. The average molecular mass and the polydispersity indices were determined by GPC

TSH Isoforms: About a Case of Hypothyroidism in a Down's Syndrome Young Adult

Background. For unknown reasons, the prevalence of thyroid autoimmune disorders is higher in patients with Down's syndrome than in the general population. The present case strongly supports a recent evaluation of propagating screening for thyroid disease in this group of patients to assure early diagnosis of hypothyroidism. Methods. In a 25-year-old man diagnosed with Down's syndrome, clinical manifestations of hypothyroidism were lacking, but profound biochemical abnormalities were found with particularly high levels of thyroid stimulating hormone (TSH). Antigenic properties of TSH were characterized using a panel of anti-TSH antibodies. Results. Technical problems not infrequently associated with TSH measurements are convincingly ruled out. Antigenic characterization of the patient's circulating TSH revealed circulating forms of TSH different from pituitary TSH which closely resembled TSH recombinant human hormone. Conclusions. It appears counterintuitive that the bioactivity of TSH decreases in the hypothyroid state as higher bioactivity of TSH is anticipated in hypothyroidism promoted by an increased hypothalamic TRH drive. In contrast, diminished negative thyroid hormone feedback will enhance posttranslational glycosylation of TSH subunits and increase sialylation of the carbohydrate side chains. Both exert a negative effect on TSH bioactivity, only compensated by the very high levels of the hormone as in the present case

Analyses des intéractions non-spécifiques au sein de la phase de développement d'un test de "point-of-care" de la troponine I cardiaque

LYON1-BU Santé (693882101) / SudocSudocFranceF

Maladie de Niemann-Pick type C (caractérisation moléculaire et approche topologique et fonctionnelle de la protéine NPC2)

La maladie de Niemann-Pick type C est une neurolipidose à transmission autosomique récessive caractérisée par une séquestration de cholestérol libre et de glycolipides dans le système endo/lysosomal. Deux gènes sont impliqués : soit NPC1, soit NPC2. La protéine NPC2 (132 aa) est soluble, possède 3 sites potentiels de N-glycosylation et lie le cholestérol libre de manière spécifique. Après l'identification des mutations causales chez 12 familles, la localisation intracellulaire de la protéine NPC2, l'importance fonctionnelle des sites potentiels de N-glycosylation et l'impact des six mutations faux-sens identifiées chez les malades ont été étudiés. La protéine NPC2 est majoritairement lysosomale. Deux sites sont N-glycosylés (N58 et N135) et seule la chaîne fixée en N58 est importante pour la localisation et la fonction de la protéine NPC2. Un impact sur la fonction et la localisation de la protéine NPC2 a été retrouvé uniquement avec les mutations C47F, S67P, C93F et C99RLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Caractérisation moléculaire de la maladie de Niemann-Pick type C

LYON1-BU Santé (693882101) / SudocSudocFranceF

A Reference Model for Educational Adaptive Web Applications

International audienceThe adaptive hypermedia systems or adaptive web applications is a research area between hypermedia and user modeling. It can customize hyperspace to different users. The existing reference models are generic and are not dedicated to educational systems. This chapter presents in the first part, a reference model that is specific to adaptive educational hypermedia systems. This model is called ALEM (Adaptive Learning Environment Model). It consists of a domain model, a learner model, a course structuring model and an adaptation model. The main contribution of this model is modeling the adaptive learning curriculum. Furthermore, we develop the UML Tutor application which is an educational adaptive hypermedia system based on our reference model

ALEM: Un Modèle de Référence pour les Applications Web Adaptatif Educatif

International audienceLes systèmes hypermédias adaptatifs (SHA) ou les applications Web adaptatifs sont un axe de recherche entre les hypermédias et la modélisation de l’utilisateur. Les SHA permettent de personnaliser l’hyperespace aux différents utilisateurs. Les modèles de référence existants sont génériques et ne sont pas dédiés aux systèmes éducatifs. Cet article présente un modèle de référence qui est spécifique aux systèmes hypermédias adaptatifs éducatifs. Ce modèle est baptisé ALEM (Adaptive Learning Environment Model). Il est composé d’un modèle de domaine, d’un modèle d’apprenant, d’un modèle de structuration de cours et d’un modèle d’adaptation. L’apport principal de ce modèle est la modélisation du parcours personnalisé de l’apprenant

ALEM: A Reference Model for Educational Adaptive Web Applications

International audienceThe adaptive hypermedia systems or adaptive Web applications is a research area between hypermedia and user modeling. It can customize hyperspace to different users. The existing reference models are generic and are not dedicated to educational systems. This chapter presents in the first part a reference model that is specific to adaptive educational hypermedia systems. This model is called ALEM (Adaptive Learning Environment Model). It consists of a domain model, a learner model, a course structuring model and an adaptation model. The main contribution of this model is modeling the adaptive learning curriculum. Furthermore we develop the UML Tutor application which is an educational adaptive hypermedia system based on our reference model

Social recommender approach for technology-enhanced learning

(Scimago Q3, ATIEF B)International audienceThe present work fits into the context of recommender systems for educational resources, especially systems that use social information. Based on the research results in the field of recommender systems, social networks and technology-enhanced learning, we defined an educational resource recommendation approach. We rely on social relations between learners to improve recommendation accuracy. Our proposal is based on formal models that generate three types of recommendation, namely recommendation of popular resources, useful resources and recently viewed resources. We developed a learning platform which integrates our recommendation models. I