Low Temperature Heat Capacity of PuPO4

PuPO4 was prepared successfully by coprecipitation and its heat capacity measured between 5 K and 300 K by a hybrid adiabatic relaxation calorimeter. The standard entropy S0 (298.15 K) of PuPO4 was derived and a semiempirical method was used to describe the total entropy as the sum of the lattice entropy Slat and the excess entropy Sexs as verified for the iso-electronic lanthanide orthophosphates. Thus the standard entropies of some actinide (III) orthophosphates were estimated.JRC.E.6-Actinides researc

Low-temperature Study of Magnetic Ordering in Gadolinium Orthophosphate

The zero-field heat capacity shows an antiferromagnetic ordering of Gd3C in gadolinium orthophosphate at 0.8 K. The application of the external magnetic field leads to the splitting of the Gd3C ground-state multiplet. The antiferromagnetic ordering becomes gradually suppressed with increasing field, and the loss of the long-range magnetic ordering with a threshold field between 0.2 and 0.5 T is indicated by heat-capacity data. Estimated entropy of the anomaly due to magnetic ordering or the Schottky-type anomaly (above 0.5 T) is close to Rln8 as expected for Gd3C ground-state multiplet. Magnetization measurements above 2 K corroborate this magnetic behaviour.JRC.E.4-Nuclear fuel

The High-temperature Heat Capacity of LnPO4(Ln = La, Ce, Gd) by Drop Calorimetry

The high-temperature heat capacity of three lanthanide orthophosphates of monazite structure have been measured in the temperature range (450 to 1570) K. The data have been analysed in terms of a lattice term, represented by the 4f0 and 4f7 compounds LaPO4 and GdPO4, and an electronic term for CePO4. The calculated excess heat capacity thus obtained is in reasonable agreement with that calculated from the crystal field energies.JRC.E.4-Nuclear fuel

Explorer le potentiel thérapeutique des coliphages : approche curative des infections causées par <em>Escherichia coli</em> chez les oiseaux

National audienceAvian pathogenic Escherichia coli strains (APEC) are the causative agent of avian colibacillosis. This extraintestinal disease is multifactorial and is the most common pathology in poultry farming. The control of the disease is currently based on a narrow-spectrum vaccine and antibiotic therapy. However, the appearance of APEC strains that are resistant to antibiotics requires the development of alternative or complementary therapeutic strategies. Among these alternatives, the therapeutic use of bacteriophages appears feasible and is currently being reassessed in Western countries. This work aims to study the feasibility of phagotherapy for the control of avian colibacillosis. The evaluation of phagotherapy in a context of avian colibacillosis has been addressed in a few studies. In the Infectious Diseases and Public Health unit of INRA Val de Loire, eleven different coliphages have been isolated from environmental samples. Among them, five are closely related to coliphage phAPEC8 whose therapeutic efficacy has been demonstrated in the treatment of infections in humans. We have shown that two of these phages were able to reduce embryo chicken mortality infected with an APEC strain. This result confirms the therapeutic potential of this phage family in veterinary and human medicine.Les Escherichia coli pathogènes aviaires (APEC) sont l’agent étiologique de la colibacillose, pathologie extra intestinale multifactorielle la plus commune en élevage avicole. La lutte contre cette pathologie est à l’heure actuelle basée sur un vaccin à spectre étroit et l’antibiothérapie. Cependant l’apparition de souches APEC résistantes aux antibiotiques nécessite la mise en place de stratégies thérapeutiques alternatives ou complémentaires. Parmi ces alternatives, l’utilisation thérapeutique des bactériophages apparait comme crédible et est actuellement en pleine réévaluation dans les pays occidentaux. Ce travail se propose d’étudier la faisabilité de la phagothérapie pour la prise en charge de la colibacillose L’évaluation de thérapie phagique dans un contexte de colibacillose aviaire a été abordée dans quelques études. Au sein de l’unité infectiologie et Santé Publique de l’INRA Val de Loire, onze coliphages différents ont été isolés d’échantillons environnementaux. Parmi eux, cinq sont très fortement apparentés au coliphage phAPEC8 dont l’efficacité thérapeutique a été démontrée dans le traitement d’infections chez l’homme. Nous avons montré que deux de ces phages étaient capables de diminuer la mortalité embryonnaire de poulet infecté par une souche APEC. Ceci renforce le potentiel thérapeutique de cette famille de phages en médecine vétérinaire et humaine

The Low Temperature Heat Capacity of LaPO4 and GdPO4, the Thermodynamic Functions of the Monazite-type LnPO4 Series

See abstract in the article attachedJRC.E.4-Nuclear fuel

Multiscale study of different types of interface of a buffer material in powder-based directed energy deposition: Example of Ti6Al4V/Ti6Al4V - Mo/Mo -Inconel 718

International audienceWhen it is difficult to deposit a material A on a material B, it is possible to create a Functionally Graded Material (FGM) using a buffer material between them to avoid the appearance of defects. The literature shows that it is very difficult, nay impossible, to have an efficient metallurgical bond between Ti6Al4V and Inconel-Mo alloys without cracks, porosities or delamination. A buffer material is therefore needed (here 25% Ti6Al4V-75% Mo) and the fine analysis of the two interfaces thus created makes it possible to define the relevance of the choice of the buffer. Moreover, the understanding of the phenomena taking place at the interface allows the preservation of the structural integrity of a FGM made by additive manufacturing. CLAD® powder-based directed energy deposition allows the building of parts containing FGM and/or buffer materials directly during the process. The study of the interfaces at both sides of the buffer material is essential. In this paper, the first interface 100 Ti6Al4V / 25 Ti6Al4V-75 Mo (in wt%) is smooth, suggesting that there has been diffusion between both alloys. The second one, 25 Ti6Al4V-75 Mo / 30 Inconel 718-70 Mo, contains numerous exotic structures between both alloys. For such a sharp interface, we show in this paper that a microscopic study is not sufficient, but a finer scale is necessary to have a good metallurgical insight. Thus, EDS, TKD and X-ray crystallography were performed right on this interface and revealed three main structures: a hexagonal matrix, a cubic structure and an ordered hexagonal one. The hexagonal matrix appears to consist of Ni 3 Ti and the ordered hexagonal one of NiMo

Efficacy of coliphages to prevent chicken embryo mortality

International audienc

Medial vascular calcification revisited: review and perspectives

International audienceVascular calcifications (VCs) are actively regulated biological processes associated with crystallization of hydroxyapatite in the extracellular matrix and in cells of the media (VCm) or intima (VCi) of the arterial wall. Both patterns of VC often coincide and occur in patients with type II diabetes, chronic kidney disease, and other less frequent disorders; VCs are also typical in senile degeneration. In this article, we review the current state of knowledge about the pathology, molecular biology, and nosology of VCm, expand on potential mechanisms responsible for poor prognosis, and expose some of the directions for future research in this area