Redox properties of the carbonate molten salt Li2_2CO3_3Na2_2CO3_3-K2_2CO3_3

International audienceThe objective of this work is to study the Li2CO3Na2CO3-K2CO3 (29.5–31.1–39.4 mol%) molten salt and the behaviour of several metals (Au, Pt, C, Ni and W) by electrochemical measurements in the salt under three atmospheres (Ar, CO2 and O2/N2). Thermodynamic calculations show that the molten salt anodic and cathodic limits correspond to the carbonate ions oxidation and reduction to dioxygen and carbon respectively. An internal reference electrode has been defined based on the redox system Na+/Au2Na, which is independent of the lithium oxide activity. The widths of the electroactivity domain have been measured on gold working electrode by cyclic voltammetry: 2.21 V under Ar and O2/N2 and 2.41 V under CO2, which are larger than the values obtained by thermodynamic calculations (1.280 V and 1.025 V respectively). Gas chromatographic (GC) analysis during electrolysis at potentials ranging in the anodic limit allowed to conclude that the electrochemical domain of the carbonate molten salt is limited anodically by the oxidation of carbonate ions to dioxygen, possibly peroxide ions, and carbon dioxide. The characterisation by XRD of a platinum electrode after electrolysis at the cathodic limit has shown that the electroactivity domain of the molten salt is defined by the carbonate ions reduction into carbon, indicating that CO32−/C is an irreversible system. A carbonate ions decomposition rate of 1 × 10-3 mmol.h-1.cm−2 has been determined by GC and thermogravimetric analysis (TGA) under inert gas. A stabilization of the CO2 pressure is observed after the melting of the salt

Contribution à l'évaluation stratégique de la recherche par l'étude des temps de premières citations

National audienceL'objectif principal de cette étude était de rechercher la durée moyenne ou médiane que mettait un article de recherche pour être cité par un autre auteur. C'est pourquoi, nous avons relevé les données temporelles correspondant à la durée entre la publication de l'article et la publication du premier article le citant. Sachant que certains articles n'ont pas encore reçu de citation, nous avons donc constitué une base de données temporelles incluant des données censurées. A partir de ce moment, nous avons recherché un modèle mathématique qui correspond à la distribution de ces données en fonction de la quantité d'articles de l'ensemble. En utilisant la loi de hasard, (en particulier la fonction de hasard), il est possible de traiter ces données graphiquement. Très vite nous nous sommes aperçus que ces ensembles semblent suivre une distribution Log-Normal à partir de laquelle il est possible de relever 2 coefficients suffisamment significatifs pour caractériser la distribution. Le coefficient > qui montre l'immédiateté de l'apparition de la première citation : plus il est petit et plus la probabilité instantanée d'apparition de cette citation est forte, ce qui signifie que si > est petit la probabilité d'apparition de première citation d'un article encore non-cité est très forte dans un futur proche. Le coefficient > qui indique le temps médian (pour 50% des articles) de première citation de la base de données étudiées

An innovative floating gastro retentive dosage system: Formulation and in vitro evaluation

International audienceOver the years, different formulation technologies intended for gastro retentive dosage delivery were investigated and patented. The aim of this study was to develop an innovative floating gastro retentive dosage form (GRDF). The developed technology induces a low-density dosage form containing high active pharmaceutical ingredient (API) concentration by using a hydrophobic dusty powder excipient under specific conditions. The new dosage form was obtained by state of the art wet granulation manufacturing process. An experimental design using a discrete variable and four mixture variables was conducted in order to optimize API concentration and buoyancy of the new dosage form. An apparatus was developed to measure the apparent density of floating tablet. The GRDF was characterized for apparent density, buoyancy, porosity and dissolution using in vitro experimentations

In Vitro Cocktail Effects of PCB-DL (PCB118) and Bulky PCB (PCB153) with BaP on Adipogenesis and on Expression of Genes Involved in the Establishment of a Pro-Inflammatory State

(1) Objective: Highlight the in vitro effects of 3T3-L1 cell exposure to polychlorinated biphenyls (PCB118 and 153) or benzo(a)pyrene (BaP) alone or as a cocktail on adipogenesis (ADG) by focusing on changes in lipid metabolism and inflammatory-related genes expression (INFG) and ADG-related genes expression (ADGG); (2) Results: Treatment from the early stage of cell differentiation by BaP alone or in combination with PCBs decreased the expression of some of the ADGG (PPARγ Glut-4, FAS, Lipin-1a, Leptin, and Adiponectin). BaP enhanced the INFG, especially MCP-1 and TNFα. Co-exposure to BaP and PCB153 showed a synergistic effect on TNFα and IL6 expression. Treatment with BaP and PCBs during only the maturation period up-regulated the INFG (IL6, TNFα, CXCL-10 & MCP-1). PCB118 alone also enhanced TNFα, CXCL-10, and PAI-1 expression. The change in MCP-1 protein expression was in agreement with that of the gene. Finally, the BaP-induced up-regulation of the xenobiotic responsive element (XRE)-controlled luciferase activity was impaired by PCB153 but not by PCB118; (3) Conclusion: BaP and PCBs down-regulate a part of ADGG and enhance INFG. The direct regulatory effect of PCBs on both ADGG and INFG is usually rather lower than that of BaP and synergistic or antagonistic cocktail effects are clearly observed

Stability of a highly concentrated solution of epirubicin for conventional transcatheter arterial chemoembolization

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Thermodynamic study of the interaction between calcium and zoledronic acid by calorimetry

International audienceBisphosphonates (BPs) are widely used to treat calcium disorders because of their structural and functional similarities with the organic pyrophosphates present in plasma and urine. BPs are well known for their strong interactions with calcium, and they have been shown to bind to hydroxyapatite or bone; however, no model exists for studying in greater detail how BPs and particularly amino-bisphosphonates (N-BPs) such as zolendronate (Zol) bind to free calcium. The aim of this work was to determine the effect of pH on Ca2+/Zol complex formation using isothermal titration calorimetry (ITC) because these effects might have important implications for the future development of a solid dosage form. In this study, using a predictive model, we can observe, the existence of three Ca2+/Zol complexes. Knowledge of the binding constant for each complex is helpful for predicting the predominance of the different species at different Ca2+/Zol ratios. Binding is due to ionic interaction between Ca2+ and the negative charges formed by dissociated Zol as a function of the pKa. Ca2+ fixation induces a strong rearrangement of the surrounding water molecules and causes proton release or uptake. The pH-dependent affinity of calcium for each site based on the model used in this work is proposed in detail, which might facilitate the development of new bisphosphonates and enable further elucidation of their mode of action. (C) 2016 Elsevier Ltd. All rights reserved

Evidence for Multiple B- and T-Cell Epitopes in Plasmodium falciparum Liver-Stage Antigen 3▿

Liver-stage antigen 3 (LSA-3) is a new vaccine candidate that can induce protection against Plasmodium falciparum sporozoite challenge. Using a series of long synthetic peptides (LSP) encompassing most of the 210-kDa LSA-3 protein, a study of the antigenicity of this protein was carried out in 203 inhabitants from the villages of Dielmo (n = 143) and Ndiop (n = 60) in Senegal (the level of malaria transmission differs in these two villages). Lymphocyte responses to each individual LSA-3 peptide were recorded, some at high prevalences (up to 43%). Antibodies were also detected to each of the 20 peptides, many at high prevalence (up to 84% of responders), and were directed to both nonrepeat and repeat regions. Immune responses to LSA-3 were detectable even in individuals of less than 5 years of age and increased with age and hence exposure to malaria, although they were not directly related to the level of malaria transmission. Thus, several valuable T- and B-cell epitopes were characterized all along the LSA-3 protein, supporting the antigenicity of this P. falciparum vaccine candidate. Finally, antibodies specific for peptide LSP10 located in a nonrepeat region of LSA-3 were found significantly associated with a lower risk of malaria attack over 1 year of daily clinical follow-up in children between the ages of 7 and 15 years, but not in older individuals

The Transcriptional Effects of PCB118 and PCB153 on the Liver, Adipose Tissue, Muscle and Colon of Mice: Highlighting of Glut4 and Lipin1 as Main Target Genes for PCB Induced Metabolic Disorders.

Epidemiological studies have associated environmental exposure to polychlorinated biphenyls (PCBs) with an increased risk of type 2 diabetes; however, little is known about the underlying mechanisms involved in the metabolic side-effects of PCB. Our study evaluated the transcriptional effects of a subchronic exposure (gavage at Day 0 and Day 15 with 10 or 100 μmol/Kg bw) to PCB118 (dioxin-like PCB), PCB153 (non-dioxin-like PCB), or an equimolar mixture of PCB118 and PCB153 on various tissues (liver, visceral adipose tissue, muscle, and colon) in mice. Our results showed that a short-term exposure to PCB118 and/or PCB153 enhanced circulating triglyceride levels but did not affect glycemia. Among the studied tissues, we did not observe any modification of the expression of inflammation-related genes, such as cytokines or chemokines. The main transcriptional effects were observed in visceral adipose and liver tissues. We found a downregulation of lipin1 and glut4 expression in these two target organs. In adipose tissue, we also showed a downregulation of Agpat2, Slc25a1, and Fasn. All of these genes are involved in lipid metabolism and insulin resistance. In muscles, we observed an induction of CnR1 and Foxo3 expression, which may be partly involved in PCB metabolic effects. In summary, our results suggest that lipin1 and glut4, notably in adipose tissue, are the main targeted genes in PCB-induced metabolic disorders, however, further studies are required to fully elucidate the mechanisms involved

Primers used for real-time qRT-PCR experiments.

<p>Primers used for real-time qRT-PCR experiments.</p