A different distribution of corticotropin releasing factor and arginine vasopressin contents in the hypothalamic nuclei after estrogen administration.

The distribution of corticotropin releasing factor (CRF) and arginine vasopressin (AVP) in hypothalamic nuclei were examined in control and estrogen-treated female rats. CRF activity was measured using monolayer cultured rat anterior pituitary cells and AVP by radioimmunoassay. Hypothalamic nuclei were punched out according to the method of Palkovits. The distribution of CRF activity in 5 different hypothalamic nuclei was similar to that of AVP in intact female rats. CRF activity in hypothalamic nuclei, pituitary ACTH content and plasma ACTH levels in estrogen-treated rats were not significantly different from those in control rats. However, significant elevation of AVP content was observed in the supraoptic and paraventricular nuclei of estrogen-treated rats. These results indicate that CRF and AVP are distributed in similar hypothalamic nuclei, but that they are not identical.</p

Spectroscopie d'absorption appliquée à l'étude de la formation des oxydes d'azote dans une chambre de combustion à volume constant

POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Structure and growth behavior of centimeter-sized helical oleate assemblies formed with assistance of medium-length carboxylic acids

The nonequilibrium organization of self-assemblies from small building-block molecules offers an attractive and essential means to develop advanced functional materials and to understand the intrinsic nature of life systems. Fatty acids are well-known amphiphiles that form self-assemblies of several shapes. Here, we found that the lengths of helical structures of oleic acid formed in a buffered aqueous solution are dramatically different by the presence or absence of certain amphiphilic carboxylic acids. For example, under the coexistence of a small amount of N-decanoyl-L-alanine, we observed the formation of over 1 centimeter-long helical assemblies of oleate with a regular pitch and radius, whereas mainly less than 100 μm-long helices formed without this additive. Such long helical assemblies are unique in terms of their highly dimensional helical structure and growth dynamics. Results from the real-time observation of self-assembly formation, site-selective small-angle X-ray scattering, high-performance liquid chromatography analysis, and pH titration experiments suggested that the coexisting carboxylates assist in elongation by supplying oleate molecules to a scaffold for oleate helical assembly

Etude expérimentale de la combustion d'un mélange méthane-air hétérogène globalement pauvre

POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Etude expérimentale de la combustion de mélanges stratifiés globalement pauvres en chambre à volume constant

POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Interactions entre une combustion turbulente et la paroi dans une enceinte fermée

Au cours de ce travail, nous étudions expérimentalement les interactions d'une flamme prémélangée avec une paroi dans une enceinte fermée. Une première approche bibliographique permet d'identifier les différentes grandeurs caractéristiques de l'interaction. Des diagnostics sont spécialement mis en place pour mesurer deux de ces grandeurs : la distance de coincement dQ et la densité de flux pariétal échangée à l'instant de coincement qw. L'étude en régime laminaire montre que dQ, mesurée par visualisation directe, décroît avec la pression et la température de paroi et que qw croît avec la pression. L'équation, généralement utilisée dans la littérature pour lier dQ à qw, est mise en défaut. L'étude en régime turbulent montre que qw ne dépend pas de la turbulence sur la plage étudiée (100<Ret<2000), laissant supposer que l'interaction entre une flamme turbulente et une paroi est assimilable à une interaction laminaire.Premixed flame-wall interaction is experimentally studied inside a closed vessel. Interaction features are first investigated through a literature review. Specific diagnostics are then developed to measure two of these features: flame quenching distance dQ and wall heat flux density qw during quenching phenomena. For laminar flames dQ is found to decrease when pressure and wall temperature increase. In the same configuration qw is found to increase with pressure. The formula usually linking qw to dQ is found to be wrong. Then, the investigation of the turbulent regime shows that qw is not dependent on turbulence for Reynolds numbers between 100 and 2000. This result suggests that the turbulent flame interaction may be assumed to be similar to the laminar interaction.POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Macroscopic motion of supramolecular assemblies actuated by photoisomerization of azobenzene derivatives

Submillimetre size self-assemblies composed of oleate and azobenzene derivatives show forceful motions such as screw-type coiling-recoiling motion by photoirradiation