Modelización de la fusión parcial en equilibrio en una fuente mantélica metasomatizada. El volcanismo Cuaternario de La Garrotxa (Cataluña)

Trace element modelling together with the use of radiogenic and stable isotopic ratios, is a widely used tool to constrain the characteristics of the mantle sources of basaltic series. However, as the composition of the volcanic rocks may be the result of several combined magmatic processes, it is necessary to identify them before any attempt to their quantitative modelling. On the other hand, the information provided by partial melting modelling is limited to the final composition of the mantle source whereas some characteristics, like the presence of minor phases, can be cloaked if those minerals have not remained in the residue. A good example to illustrate the problems of this method is found in the Quaternary primitive basaltic rocks of La Garrotxa (ME Volcanic Region of Spain) which, according to a combined study o f trace element modelling and Sr-Nd-Pb isotopic ratios, can be interpreted as the result of the melting of a previously enriched lithospheric source which has been subsequently pervaded by basaltic melts derived from a common European sublithospheric reservoir

Microparticles are new biomarkers of septic shock-induced disseminated intravascular coagulopathy

PURPOSE: Septic shock-induced disseminated intravascular coagulopathy (DIC) contributes to multiple organ failure. Mechanisms governing vascular responses to open occurrence of DIC have not yet been established. Circulating plasma microparticles (MPs), released upon cell stress, constitute a catalytic procoagulant surface and are surrogates of vascular cell activation/injury. Herein, MPs were assessed as possible markers of haemostatic and vascular dysfunction in the DIC time course. METHODS: One hundred patients with septic shock from three ICUs were enrolled and their haemostatic status evaluated at admission (D1), D2, D3 and D7. Circulating procoagulant MPs were isolated, quantified by prothrombinase assay and their cellular origin determined. DIC diagnosis was made according to the JAAM 2006 score. RESULTS: Ninety-two patients were analysed and 40 had DIC during the first 24 h. Routine clotting times and factor/inhibitor activity did not allow assessing vascular cell involvement. At admission, thrombin generation and fibrinolysis were observed in both groups while impaired fibrin polymerisation was evidenced only in DIC patients. Sustained thrombin generation persisted over time in both groups at D7. While total microparticle concentrations were in the same range regardless of DIC diagnosis, specific phenotypes were already detected at admission in DIC patients. Endothelial- and leucocyte-derived MPs were higher in DIC while an increased soluble glycoprotein V/platelet ratio was delayed, underscoring the first involvement of endothelial cells and leucocytes whereas platelet activation was delayed. Endothelium-derived CD105-MPs (OR 6.55) and CD31-MPs (OR 0.49) were strongly associated with early DIC in multivariate analysis. CONCLUSION: Endothelial-derived microparticles are relevant biomarkers of septic shock-induced DIC and could be used to evaluate early vascular injury

Cannabis sativa terpenes are cannabimimetic and selectively enhance cannabinoid activity

Limited evidence has suggested that terpenes found in Cannabis sativa are analgesic, and could produce an “entourage effect” whereby they modulate cannabinoids to result in improved outcomes. However this hypothesis is controversial, with limited evidence. We thus investigated Cannabis sativa terpenes alone and with the cannabinoid agonist WIN55,212 using in vitro and in vivo approaches. We found that the terpenes α-humulene, geraniol, linalool, and β-pinene produced cannabinoid tetrad behaviors in mice, suggesting cannabimimetic activity. Some behaviors could be blocked by cannabinoid or adenosine receptor antagonists, suggesting a mixed mechanism of action. These behavioral effects were selectively additive with WIN55,212, suggesting terpenes can boost cannabinoid activity. In vitro experiments showed that all terpenes activated the CB1R, while some activated other targets. Our findings suggest that these Cannabis terpenes are multifunctional cannabimimetic ligands that provide conceptual support for the entourage effect hypothesis and could be used to enhance the therapeutic properties of cannabinoids. © 2021, The Author(s).Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Performance and Degradation Mechanisms of Thermal Barrier Coatings for Turbine Blades: a Review of ONERA Activities

International audienceThermal barrier coatings are used to protect blades and vanes in the hot sections of gas turbines. They consist of a thick porous ceramic layer deposited on an alumina forming metallic bond coat in contact with the nickel-based superalloy substrate. They are designed to prolong the components lifetimes or to increase gas temperature, and therefore efficiency. In service the structure and composition of the various layers evolve, due to sintering of the ceramic layer, oxidation of the bond coat, and interdiffusion phenomena with the substrate. As a result the properties of each layer are affected, as well as interfacial toughness. These evolutions, combined with applied external stresses may lead to bond coat rumpling, crack formation at the bond coat/ceramic interface and eventually the ceramic layer may spall off. In addition to these intrinsic degradation modes, interactions with environment can accelerate the system degradation. The present paper reviews the ageing phenomena occurring in thermal barrier coatings at high temperature and describe their degradation mechanisms, with illustrations taken from service experience and laboratory tests

10 Years-Activities at ONERA on Advanced Thermal Barrier Coatings

International audienceDeveloping thermal barrier coatings operating at higher temperature and/or for very long durations (commercial aircraft applications) is one of the technological and economical challenges for engine manufacturers. This includes the search for (i) low thermal conductivity, high thermal stability and CMAS resistant ceramic top coat, and (ii) alternative low cost bond coat with improved oxidation resistance and chemical compatibility with the substrate. This paper reviews the rationale sustaining the choice of new materials for each layer and presents some recommendations to develop more robust and more efficient systems with increased lifetime

Oxidation model for carbon-carbon composites

Tire de :'AIAA 4th International Aerospace Planes Conference', Orlando, FL (USA), December 1-4, 1992SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1992 n.210 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Multifunctional enkephalin analogs with a new biological profile: Mor/dor agonism and kor antagonism

In our previous studies, we developed a series of mixed MOR/DOR agonists that are enkephalin-like tetrapeptide analogs with an N-phenyl-N-piperidin-4-ylpropionamide (Ppp) moiety at the C-terminus. Further SAR study on the analogs, initiated by the findings from off-target screening, resulted in the discovery of LYS744 (6, Dmt-DNle-Gly-Phe(p-Cl)-Ppp), a multifunctional ligand with MOR/DOR agonist and KOR antagonist activity (GTPS assay: IC50 = 52 nM, Imax = 122% cf. IC50 = 59 nM, Imax = 100% for naloxone) with nanomolar range of binding affinity (Ki = 1.3 nM cf.Ki = 2.4 nM for salvinorin A). Based on its unique biological profile, 6 is considered to possess high therapeutic potential for the treatment of chronic pain by modulating pathological KOR activation while retaining analgesic efficacy attributed to its MOR/DOR agonist activity. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]