TROUBLES DE VIGILANCE DES INTERNES A L'ISSUE DE LEUR GARDE (CAUSES ET CONSEQUENCES)

PARIS7-Villemin (751102101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Allaitement maternel (connaissances et conduites pratique : enquête auprès de 30 médecins généralistes du Nord-Finistère)

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Rhodium-and cobalt-based cathodes with low metal loading for electrocatalytic hydrogen evolution under neutral pH conditions

International audienceRhodium- and cobalt-based cathodes with low metal loading for electrocatalytic hydrogen evolution under neutral pH conditionsChristophe Orain,a Lucia Alvarez-Miguel,a Aymeric Garnier,a Nolwenn Cabon,a andFrédéric Gloaguen aa CEMCA, UMR 6521, CNRS, Univ Brest, 29200 Brest, FranceEmail: [email protected] the increasing availability of electricity produced from renewable energy sources (e.g. sun and wind), water electrolysis has emerged as a viable technology for the clean production of hydrogen (H2).1 Electrocatalysis of the H2 evolution reaction (HER) at both noble metal and noble metal-free cathodes has been extensively investigated under strongly acidic or alkaline pH conditions, where it is the most efficient. However, the setting-up of H2 production systems working at very low or very high pH entails several practical drawbacks, especially those linked to corrosion.On the other hand, HER electrocatalysts able to work under kinetically unfavorable neutral/near-neutral pH conditions have been scarcely investigated.2 Importantly, such electrocatalysts might be suitable for integration into hybrid biological inorganic (HBI) systems, which have the potential to overcome the challenges facing “pure” biological or inorganic systems for carbon dioxide (CO2) and nitrogen (N2) fixation.3In this context, we report here preliminary results on the HER at neutral pH by rhodium and cobalt-based cathodes with low metal loading. The electrodes were prepared by reacting a solution of pentamethylcyclopentadienide 1,10-phenanthroline-5,6-diamine complex of Rh or Co with an oxidized carbon surface leading to the attachment of the metal complex through covalent and conjugated bonds.4 This approach, related to that of Surface Organometallic Catalysis (SOMCat),5 offers the prospect of synthesizing electrocatalysts in which the chemical environment of dispersed single metal sites is well-controlled and remains well-defined. A rhodium-based cathode prepared by this method with metal loading as low as 6.6 103 mg cm2 has already shown its efficiency and stability for the HER under strongly acidic pH conditions.6References(1) Grigoriev, S.A.; Fateev, V.N.; Bessarabov, D.G.; Millet, P. Int. J. Hydrogen Energy 2020, 45 (49), 26036–26058.(2) Zhou, Z.; Pei, Z.; Wei, L.; Zhao, S.; Jian, X.; Chen, Y. Energy Environ. Sci. 2020, 13(10), 3185–3206.(3) Nangle, S.N.; Sakimoto, K.K.; Silver, P.A.; Nocera, D.G. Curr. Opin. Chem. Biol. 2017, 41, 107–113.(4) Jackson, N.; Kaminsky, C.J.; Oh, S.; Melville, F.; Surendranath, Y. J. Am. Chem. Soc. 2019, 141, 14160.(5) Samantaray, M.K.; D’Elia, V.; Pump, E.; Falivene, L.; Harb, M.; Ould Chikh, S.; Cavallo, L.; Basset, J.-M. Chem. Rev. 2020, 120 (2), 734–813.(6) Pérez, G.; Diaz-Sainz, G.; Gómez-Coma, L.; Álvarez-Miguel, L.; Garnier, A.; Cabon, N., Ortiz, A.; Gloaguen, F.; Ortiz, I. J. Environ. Chem. Eng. 2022, 10, 107682

Body stores of emergent aquatic insects are associated with body size, sex, swarming behaviour and dispersal strategies

Dispersal is a determining step in the life cycle of insects and a key factor of their energy budget. If the body stores of terrestrial insects are relatively well-documented, those of merolimnic insects (i.e., with aquatic larvae and terrestrial winged adults) remain poorly investigated. We assayed the body stores (protein, carbohydrate and lipid contents) of 18 families of merolimnic insects, encompassing a wide diversity of biological and ecological traits. We highlighted allometry between body stores and mass. The proportion of triglyceride and free carbohydrate relatively decreases with an increase in absolute insect mass, whereas protein and glycogen contents are proportional. We found a significant effect of insect order, Diptera having relatively more proteins than Trichoptera. For swarming taxa, males have relatively more triglycerides than their conspecific female. Passive dispersers are characterised by higher protein and glycogen contents Each body store was associated with specific life-history traits, emphasising the importance of considering each body store independently to better understand the associated functions. Dispersal strategies seem to be the main structuring factor underlying body store patterns of merolimnic insects, being significantly associated with the variation in adjusted triglycerides (30%), proteins (21%), glycogen (29%) and free carbohydrates (17%). However, our study estimated the role of flight only indirectly through the biological traits of insects. Future works should focus on identifying which substrates are used for flight, by comparing the proportion of body stores before and after flight, as well as protein identification to distinguish proteins associated with flight or reproduction. These further studies will help researchers in understanding the link between body stores of emerging merolimnic insects and the various facets of their ecology

Electrodes modified with Rhodium or Cobalt organometallic complexes for hydrogen production in aqueous electrolyte

International audienceWe are currently engaged in a project [1] aimed at demonstrating the fixation of dinitrogen (N2, a very stable molecule) to ammonium (NH4+, an essential fertilizer) by a cathode colonized by a mixed biofilm accepting electrons directly from the electrode or in the form of dihydrogen (H2) electrogenerated at the electrode.In this context, our primary objective is to elaborate electrodes that are biocompatible and can produce H2 under biological conditions, i.e. in aqueous electrolyte at neutral pH. Here we report preliminary results on electrodes modified by [Cp*RhCl(phendiamine)]+ or [Cp*Co(CH3CN)(phendiamine)]2+ (scheme 1). The diamine moiety allows the grafting of these organometallic complexes on oxidized carbon surfaces through covalent and conjugatedbonds [2]. The rhodium complex grafted on oxidized carbon black powder (Vulcan) has already shown its efficiency and stability under strongly acidic conditions [3]. Herein, we scrutinize its electrochemical behaviour in less acidic electrolytes and compare them to those of the cobalt related complex, which could represent an abundant transition metal alternative.[1] CATHOMIX, Projet n° ANR-19-CE43-0013-02.[2] M.N. Jackson, C.J. Kaminsky, S. Oh, J.F. Melville, Y. Surendranath, J. Am. Chem. Soc., 2019, 141, 14160.[3] G. Pérez, G. Diaz-Sainz, L. Gómez-Coma, L. Álvarez-Miguel, A. Garnier, N. Cabon, A. Ortiz, F. Gloaguen, I. Ortiz, J. Environ. Chem. Eng., 2022, 10, 107682

Radio-over-Fiber Transport for the Support of Broadband Services

Some of the work carried out within the EU Network of Excellence ISIS on radio-over-fiber systems for the support of current and emerging wireless networks is reviewed. Direct laser modulation and externally modulated links have been investigated, and demonstrations of single-mode fiber and multimode fiber systems are presented. The wireless networks studied range from personal area networks (such as ZigBee and ultrawideband) through wireless local area networks to wireless metropolitan area networks (WiMAX) and third-generation mobile communications systems. The performance of the radio-over-fiber transmission is referenced to the specifications of the relevant standard, protocol operation is verified, and complete network demonstrations are implemented

Mitochondrial AIF Loss Causes Metabolic Reprogramming, Caspase-Independent Cell Death Blockade, Embryonic Lethality, and Perinatal Hydrocephalus

International audienceObjectives: Apoptosis-Inducing Factor (AIF) is a protein involved in mitochondrial electron transport chain assembly/stability and in programmed cell death. The relevant role of this protein is underlined by the fact that mutations altering mitochondrial AIF properties result in acute pediatric mitochondriopathies and tumor metastasis. By generating an original AIF-deficient mouse strain, the present study sought to analyze, in a single paradigm, the cellular and developmental metabolic consequences of AIF loss and the subsequent oxidative phosphorylation (OXPHOS) dysfunction.Methods: We developed a novel AIF-deficient mouse strain and assessed, by molecular and cell biology approaches, the cellular, embryonic, and adult mice phenotypic alterations. Additionally, we carried out ex vivo assays with primary and immortalized AIF knockout mouse embryonic fibroblasts (MEFs) to establish the cell death characteristics and the metabolic adaptive responses provoked by the mitochondrial electron transport chain (ETC) breakdown.Results: AIF deficiency destabilized mitochondrial ETC and provoked supercomplex disorganization, mitochondrial transmembrane potential loss, and high generation of mitochondrial reactive oxygen species (ROS). AIF-/Y MEFs counterbalanced these OXPHOS alterations by mitochondrial network reorganization and a metabolic reprogramming towards anaerobic glycolysis illustrated by the AMPK phosphorylation at Thr172, the overexpression of the glucose assimilation transporter GLUT-4, the subsequent enhancement of glucose uptake, and the anaerobic lactate generation. A late phenotype was characterized by the activation of P53/P21-mediated senescence. Interestingly, about 2% of AIF-/Y MEFs diminished both mitochondrial mass and ROS levels and spontaneously proliferated. These cycling AIF-/Y MEFs were resistant to caspase-independent cell death inducers. The AIF-deficient mouse strain was embryonic lethal between E11.5 and E13.5 with energy loss, proliferation arrest, and increased apoptotic levels. Contrary to AIF-/Y MEFs, the AIF KO embryos were unable to reprogram their metabolism towards anaerobic glycolysis. Heterozygous AIF-/+ females displayed a progressive bone marrow, thymus, and spleen cellular loss. In addition, about 10% of AIF-/+ females developed perinatal hydrocephaly characterized by brain development impairment, meningeal fibrosis, and medullar hemorrhages; those mice died around 5 weeks of age. AIF-/+ with hydrocephaly exhibited loss of ciliated epithelium in the ependymal layer. This phenotype seemed triggered by the ROS excess. Accordingly, it was possible to diminish the occurrence of hydrocephalus AIF-/+ females by supplying dams and newborns with an antioxidant in drinking water.Conclusion: In a single knockout model and at three different levels (cell, embryo, and adult mice) we demonstrated that, by controlling the mitochondrial OXPHOS/metabolism, AIF is a key factor regulating cell differentiation and fate. Additionally, by shedding new light on the pathological consequences of mitochondrial OXPHOS dysfunction, our new findings pave the way for novel pharmacological strategies

Factors Associated with Asthma Severity in Children: Data from the French COBRAPed Cohort

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Mitochondrial inhibitors circumvent adaptive resistance to venetoclax and cytarabine combination therapy in acute myeloid leukemia

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