11 research outputs found

    Questioning the structure of Sr

    No full text
    The stable structures of argon clusters doped with a strontium cation were computationally determined using a many-body polarizable potential fitted to reproduce highly accurate electronic structure calculations at the coupled cluster level of theory. The basin-hopping global optimization method was employed to locate putative lowest energy structures of Sr+Arn clusters with n < 160, and the effects of zero-point energy corrections and of possible entropy-driven structural transitions were accounted for in the (quantum) harmonic approximation. The results suggest an overall icosahedral growth pattern over the investigated size range, with the strontium cation being generally twelvefold coordinated by argon atoms also arranged into an icosahedron. However, the strain between the first coordination shell and the remaining cluster is significant, with the cation not always residing at the center of the cluster despite being much more strongly bound. As a result, non-icosahedral coordination shells are also occasionally found with local decahedral or cubic arrangements. This structural diversity could explain the relative discrepancies with existing mass spectrometry abundances

    Enhancement of fermentative hydrogen production by Thermotoga maritima through hyperthermophilic anaerobic co-digestion of fruit-vegetable and fish wastes

    No full text
    International audienceIn this work, different proportions of model fruit and vegetable wastes (MFVW) and acid hydrolyzed fish wastes (AHFW) were used for hydrogen production in a minimum culture medium based on seawater. Experiments were performed in pH-controlled Stirred Tank Reactor (STR) with or without the addition of nitrogen and sulfur sources. The total H2 production and the maximum hydrogen productivity of T. maritima in the culture medium, containing MFVW and AHFW (45 mmol L−1 carbohydrates) at a C/N ratio of 12, were 132 mmol L−1 and 15 mmol h−1 L−1, respectively. However, tripling the concentration of carbohydrates to reach a C/N ratio of 22, has increased two times the maximum H2 productivity (28 mmol h−1 L−1) due to the improvement in nutrient balance. The cumulative H2 production was 285 mmol L−1, yielding a potential energy generation of 0.12103 MJ ton−1 wastes, which could be an interesting alternative for energy recovery

    A simple gas pressure manometer for measuring hydrogen production by hydrogenogenic cultures in serum bottles

    No full text
    International audienceThis study investigated the determination of hydrogen production by three H2-producing microorganisms (Thermotoga maritima, Thermococcus kodakarensis KOD1 and Enterobacter cloacae) cultured in 116-mL serum bottles. A gas pressure manometer was used to measure total pressure in the serum-bottle headspace. It was demonstrated that total pressure is the sum of the saturation pressure of water, the pressure expansion of gases, and the partial pressures of H2 () and CO2 (). A linear relationship was established between the partial pressure of H2 measured by gas chromatography and the sum of the partial pressures of H2 and CO2 measured by the manometer. When pH of culture medium was not controlled (pH decreased from 7 to 5), the ratio was close to stoichiometric H2/CO2 yield ratio of the most plausible metabolic pathways of each strain. values were 1.7, 1.9 and 0.9 for T. maritima, T. kodakarensis and E. cloacae, respectively. In these experimental conditions, can be deduced from total pressure measured by manometer

    A regionally based precision medicine implementation initiative in North Africa:The PerMediNA consortium

    No full text
    International audiencePrecision Medicine is being increasingly used in the developed world to improve health care. While several Precision Medicine (PM) initiatives have been launched worldwide, their implementations have proven to be more challenging particularly in low- and middle-income countries. To address this issue, the “Personalized Medicine in North Africa” initiative (PerMediNA) was launched in three North African countries namely Tunisia, Algeria and Morocco. PerMediNA is coordinated by Institut Pasteur de Tunis together with the French Ministry for Europe and Foreign Affairs, with the support of Institut Pasteur in France. The project is carried out along with Institut Pasteur d’AlgĂ©rie and Institut Pasteur du Maroc in collaboration with national and international leading institutions in the field of PM including Institut Gustave Roussy in Paris. PerMediNA aims to assess the readiness level of PM implementation in North Africa, to strengthen PM infrastructure, to provide workforce training, to generate genomic data on North African populations, to implement cost effective, affordable and sustainable genetic testing for cancer patients and to inform policy makers on how to translate research knowledge into health products and services. Gender equity and involvement of young scientists in this implementation process are other key goals of the PerMediNA project.In this paper, we are describing PerMediNA as the first PM implementation initiative in North Africa. Such initiatives contribute significantly in shortening existing health disparities and inequities between developed and developing countries and accelerate access to innovative treatments for global health
    corecore