PbSrYCaCuO : a new class of superconducting materials. Chemical analyses refined by Energy Dispersive X-rays

A new class of superconducting material - PbSrYCaCuO - has been recently synthesized. Energy Dispersive X-ray analyses of a sample prepared in our laboratory indicate that 80 % of the matrix is constituted by the Pb 2.25Sr1.95Y0.72Ca0.28Cu2.95O 8.5 compound, 12 % represents random compositions and 8 % corresponds to (Ca, Sr) CuOx compounds. Chemical cartography and maps correlation illustrate such conclusions. Some new electron diffraction data are correlated to these analyses

PbSrYCaCuO : a new class of superconducting materials. Chemical analyses refined by Energy Dispersive X-rays

A new class of superconducting material - PbSrYCaCuO - has been recently synthesized. Energy Dispersive X-ray analyses of a sample prepared in our laboratory indicate that 80 % of the matrix is constituted by the Pb 2.25Sr1.95Y0.72Ca0.28Cu2.95O 8.5 compound, 12 % represents random compositions and 8 % corresponds to (Ca, Sr) CuOx compounds. Chemical cartography and maps correlation illustrate such conclusions. Some new electron diffraction data are correlated to these analyses.Une nouvelle génération de matériaux supraconducteurs, de type PbSrYCaCuO, a été récemment synthétisé. Un échantillon préparé dans notre laboratoire a été analysé chimiquement par Dispersion en Energie de rayons-X (EDX). Les résultats montrent que 80 % de la matrice sont constitués par un composé de type Pb2.25Sr1.95Y0.72Ca0.28Cu 2.95O8.5, 12 % par des composés mal définis et 8 % par des composés de type (Ca, Sr) CuOx. Une cartographie chimique et des cartes de corrélation illustrent les conclusions. Quelques nouveaux résultats de diffraction électronique sont associés à ces analyses

Rapamycin Improves Recognition Memory and Normalizes Amino-Acids and Amines Levels in the Hippocampal Dentate Gyrus in Adult Rats Exposed to Ethanol during the Neonatal Period

The mammalian target of rapamycin (mTOR), a serine/ threonine kinase, is implicated in synaptic plasticity by controlling protein synthesis. Research suggests that ethanol exposure during pregnancy alters the mTOR signaling pathway in the fetal hippocampus. Thus, we investigated the influence of pre-treatment with rapamycin, an mTORC1 inhibitor, on the development of recognition memory deficits in adult rats that were neonatally exposed to ethanol. In the study, male and female rat pups received ethanol (5 g/kg/day) by intragastric intubation at postanatal day (PND 4-9), an equivalent to the third trimester of human pregnancy. Rapamycin (3 and 10 mg/kg) was given intraperitoneally before every ethanol administration. Short- and long-term recognition memory was assessed in the novel object recognition (NOR) task in adult (PND 59/60) rats. Locomotor activity and anxiety-like behavior were also evaluated to exclude the influence of such behavior on the outcome of the memory task. Moreover, the effects of rapamycin pre-treatment during neonatal ethanol exposure on the content of amino-acids and amines essential for the proper development of cognitive function in the dentate gyrus (DG) of the hippocampus was evaluated using proton magnetic resonance spectroscopy (1H MRS) in male adult (PND 60) rats. Our results show the deleterious effect of ethanol given to neonatal rats on long-term recognition memory in adults. The effect was more pronounced in male rather than female rats. Rapamycin reversed this ethanol-induced memory impairment and normalized the levels of amino acids and amines in the DG. This suggests the involvement of mTORC1 in the deleterious effect of ethanol on the developing brain

Rapamycin Improves Recognition Memory and Normalizes Amino-Acids and Amines Levels in the Hippocampal Dentate Gyrus in Adult Rats Exposed to Ethanol during the Neonatal Period

The mammalian target of rapamycin (mTOR), a serine/ threonine kinase, is implicated in synaptic plasticity by controlling protein synthesis. Research suggests that ethanol exposure during pregnancy alters the mTOR signaling pathway in the fetal hippocampus. Thus, we investigated the influence of pre-treatment with rapamycin, an mTORC1 inhibitor, on the development of recognition memory deficits in adult rats that were neonatally exposed to ethanol. In the study, male and female rat pups received ethanol (5 g/kg/day) by intragastric intubation at postanatal day (PND 4-9), an equivalent to the third trimester of human pregnancy. Rapamycin (3 and 10 mg/kg) was given intraperitoneally before every ethanol administration. Short- and long-term recognition memory was assessed in the novel object recognition (NOR) task in adult (PND 59/60) rats. Locomotor activity and anxiety-like behavior were also evaluated to exclude the influence of such behavior on the outcome of the memory task. Moreover, the effects of rapamycin pre-treatment during neonatal ethanol exposure on the content of amino-acids and amines essential for the proper development of cognitive function in the dentate gyrus (DG) of the hippocampus was evaluated using proton magnetic resonance spectroscopy (1H MRS) in male adult (PND 60) rats. Our results show the deleterious effect of ethanol given to neonatal rats on long-term recognition memory in adults. The effect was more pronounced in male rather than female rats. Rapamycin reversed this ethanol-induced memory impairment and normalized the levels of amino acids and amines in the DG. This suggests the involvement of mTORC1 in the deleterious effect of ethanol on the developing brain

HIGH TEMPERATURE SUPERCONDUCTIVITY IN Bi-Sm-Sr-Ca-Cu-O

X-ray diffraction, resistivity and magnetic susceptibility for BiSrCaCuO (2224) system and 10 % Sm substituted for Bi in (2223) system are reported. The high temperature transition at 110 K disappears when Sm is substituted while there is no major change in the lattice parameters. The possible role of Bi-O planes in the superconducting mechanism in this system is indicated

XDC AND MAGNETIC MÖSSBAUER SPECTRA OF YBa2 (Cu1-xFex)3 O7-δ

We find the paramagnetic Mössbauer spectra of YBa2 (CuxFe1-x)3 O7-δ can be fitted using symmetric doublets, iron is in high spin Fe3+ state in the oxide, and the present study provides further support to the presence of spin relaxation effects at low temperatures