Electronic properties of mixed uranium-thorium monosulphides (U xTh1-x)S

We have measured bulk magnetization, neutron magnetic scattering and specific heat between 1.5 and 300 K of mixed uranium-thorium monosulphides (U xTh1-x)S with large uranium concentrations (x ≽ 0.20). Long-range ferromagnetic order is observed at low temperature for 0.43 < x ≤ 1, but no long-range magnetic order occurs for x < 0.43. Magnetization and Curie temperature decrease linearly with uranium content. The electronic specific heat is maximum at the critical concentration xc = 0.43. Our experiments failed to reveal Schottky anomalies in specific heat or crystal-field levels by inelastic neutron scattering. Our results favour a band description rather than a localised description for uranium 5f electrons.Nous avons mesuré l'aimantation, la diffusion magnétique des neutrons et la chaleur spécifique entre 1,5 et 300 K de monosulfures mixtes d'uranium et de thorium (UxTh1-x)S contenant une proportion importante d'uranium (x ≽ 0,20). L'ordre ferromagnétique à grande distance est observé à basse température pour 0,43 < x ≤ 1, mais pour x < 0,43, il n'y a pas d'ordre magnétique à grande distance. L'aimantation spontanée et la température de Curie décroissent linéairement avec la concentration en uranium. La chaleur spécifique électronique est maximale à la concentration critique xc = 0,43. Nos mesures de chaleur spécifique n'ont pas montré d'anomalies de Schottky et nous n'avons pas observé de niveaux de champ cristallin en diffusion inélastique de neutrons. L'ensemble de nos résultats suggère une description de bande plutôt qu'une description localisée pour les électrons 5f de l'uranium

Milk fermented with yogurt cultures and Lactobacillus casei compared with yogurt and gelled milk : influence on intestinal microflora in healthy infants.

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Development of a Heterologous Model in Germfree Suckling Rats for Studies of Rotavirus Diarrhea

Germfree suckling rats were infected with an SA11 rotavirus strain. Infected pups developed diarrhea associated with histopathological changes. The virus was detected in feces and in the small intestine. Cellular vacuolation was observed in the villi of the jejunum. These results provide a new model for further investigations of group A rotavirus infection

Selected commensal-related bacteria and Toll-like receptor 3 agonist combinatorial codes synergistically induce interleukin-12 production by dendritic cells to trigger a T helper type 1 polarizing programme

Enteric infections remain a major health problem causing millions of deaths in developing countries. The interplay among the host intestinal epithelium, the mucosa-associated immune system and microbiota performs an essential role in gut homeostasis and protection against infectious diseases. Dendritic cells (DCs) play a key role in orchestrating protective immunity and tolerance in the gut. The mechanisms by which DCs adapt their responses and discriminate between virulent microbes and trillions of innocuous bacteria remain ill-defined. Here we investigated the effect of cross-talk between commensal-related bacteria (CB) and Toll-like receptor (TLR) agonists on DC activation and the outcome of the in vitro T helper response. Human monocyte-derived DCs were exposed to eight different Gram-positive or Gram-negative CB strains prior to activation with five different TLR agonists. The key polarizing cytokines interleukin (IL)-12p70, IL-10, IL-1β and IL-6 were quantified and the fate of naïve T-cell differentiation was evaluated. We identified a unique combination of Lactobacillus casei and TLR3 signals that acted in synergy to selectively increase IL-12p70 secretion. Exposure to poly(I:C) converted L. casei-treated DCs into potent promoters of T helper type 1 (Th1) responses. We propose that DCs can integrate harmless and dangerous non-self signals delivered by viral products, to mount robust Th1 responses. Thus, in vivo DC targeting with selective probiotics may improve strategies for the management of enteric diseases