We provide a unified spectroscopic evidence of efficient energy transfer (ET) from optically excited colloidal nanocrystal quantum dots (NQDs) into Si substrates in a broad range of wavelengths: from visible (545 nm) to near-infrared (800 nm). Chemical grafting of nanocrystals on hydrogenated Si surfaces is achieved via amine-modified carboxy-alkyl chain linkers, thus ensuring complete surface passivation and accurate NQD positioning. Time-resolved photoluminescence (PL) has been measured for a set of CdSe/ZnS and CdSeTe/ZnS NQDs of various sizes and compositions grafted on Si and SiO2 substrates.
View Article and Find Full Text PDFIn vitro contractility of isolated cylindrical segments of chorial arteries and veins from 40 human term placentas was studied. Contractility was recorded by an isometrical and axipetal method. Spontaneous contractility was observed in 75% of the arteries and in 45% of veins.
View Article and Find Full Text PDFActa Diabetol Lat
November 1979
Estriol serum levels, neonatal vitality and stromal villous edema were studied in diabetic pregnancies. The average serum estriol levels in diabetic patients whose placentas had villous edema was 26.45 +/- 9.
View Article and Find Full Text PDFBol Oficina Sanit Panam
December 1976
Acta Diabetol Lat
September 1977
The morphologic characteristics of the chorial villi from normal full-term placentas and from placentas of different clinical types of diabetic women were studied. The latter showed early maturation of the trophoblast, higher percentage of villi with stromal edema, and higher percentage of vessels of the villous trunks with lesions causing partial or total obstruction of the vascular lumen. The fact that the diabetic patients were treated suggests that the metabolic correction of diabetes mellitus prevents the occurrence or development of the multiple disturbances which the disease produces in the evolution of human pregnancy.
View Article and Find Full Text PDFSalbutamol effects upon the fetal vessels of the human placenta were studied in vitro, comparing the changes induced upon the critical closing pressure (CCP) and viscous resistance (R). Four normal full-term placentas were used. In each of them, 4 cotyledonary areas were perfused, thus obtaining a total of 16 measurements for the observation of spontaneous variations (blank), by perfusion with Krebs solution, and the same amount for the variations due to Salbutamol.
View Article and Find Full Text PDFBilateral injections of 30 mug of 6-hydroxydopamine (6-OHDA, as base) into the anterolateral hypothalamic area induced constant vaginal cornification (CVC), polyfollicular ovaries and uterine hypertrophy in cyclic adult female rats. There were no important changes in the vaginal patterns or ovarian and uterine morphology in animals given injections in the same area with the solvent only and in animals given injections with 6-OHDA in the anterior amygdaloid area. It is suggested that the persistent estrus after anterolateral hypothalamic injections of 6-OHDA results from lesions of central catecholaminergic pathways, which are probably involved in gonadotropin secretion.
View Article and Find Full Text PDFTo determine whether central catecholaminergic pathways are involved in the neural contral of gonadotrophin secretion, they were interrupted at the hypothalamic level by microinjections of 6-hydroxydopamine (6-OHDA). The effects on ovulation, estral cycle and ovarian and uterine histology were studied. Microinjections of 50 mug of 6-OHDA hydrobromyde were made bilaterally into the anterolateral hypothalamus in a group of rats.
View Article and Find Full Text PDFThe authors study the total water content in two different areas (parabasal and subchorial), in 40 normal, full-term placentas. The water content is found to be different in these two areas. As an average, it is 0.
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