National Nuclear Energy Commission

About: National Nuclear Energy Commission is a government organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Dosimetry & Laser. The organization has 3816 authors who have published 4694 publications receiving 59951 citations.

GeO2–PbO–Bi2O3 glasses doped with Yb3+ for laser applications

Abstract: Glasses of heavy metal oxide GeO2–PbO–Bi2O3 doped with different concentrations of Yb3+ were prepared as materials for IR emission. Absorption and fluorescence emission spectra were measured. The spectroscopic properties and laser parameters are calculated; the disagreement between the reciprocity method and Fuchtbauer–Ladenburg formula in calculations of Yb3+ emission cross-sections is discussed using the radiation trapping effect. GeO2–PbO–Bi2O3 glass doped with Yb3+ is a promising material for laser action at 1021 nm, with properties similar to other known glasses (phosphate and tellurite laser glasses) used as active laser media; the high absorption cross-section (of 1.5 × 10−20 cm2) and the large emission bandwidth (of 70 nm) are properties appropriate for short pulse generation.

Gabaergic–Benzodiazepine System is Involved in the Crotoxin-Induced Anxiogenic Effect

Abstract: The behavioral effects of crotoxin (CTX), the major component of Crotalus durissus terrificus venom, were studied in rats submitted to the open field, holeboard, and social interaction tests CTX (100, 250, and 500 μg/kg, IP) was administered 2 h before the tests In the open field, CTX reduced ambulation (250 μg/kg) and rearing (250 and 500 μg/kg) and increased grooming (100 and 250 μg/kg) and freezing (250 μg/kg) In the holeboard and social interaction, all the CTX doses evaluated decreased, respectively, head dip and head dipping, and social interaction time The CTX-induced behavioral alterations could be attributed to its neuromuscular transmission blockade, but this possibility was ruled out because CTX (250 and 500 μg/kg, IP, 2 h before the rotarod test) was unable to modify the rotarod performance of rats The involvement of the benzodiazepine receptor in the CTX-induced behavioral alterations was investigated through the pretreatment (30 min before the tests, IP) of the animals with diazepam (12 mg/kg), or flumazenil (4 and 10 mg/kg) Both diazepam and flumazenil antagonized the CTX-induced behavioral alterations in the open field, holeboard, and social interaction tests This study demonstrated that: (1) CTX is an anxiogenic compound; and (2) the gabaergic–benzodiazepine system may play a role in the CTX-induced anxiogenic effect

Metals in playground soils of São Paulo city, Brazil

Abstract: Sao Paulo is a megacity, with a population of over 20 million inhabitants. Soils have an impact on human health in many ways and young children are especially vulnerable. The concentration of As, Ba, Cr and Zn, were determined in surface soil samples from playgrounds of Sao Paulo public parks by neutron activation analysis. The results obtained in this study indicated concentration levels higher than the values considered as reference values for soils in Sao Paulo. The concentrations obtained suggest an anthropogenic source and indicate a potential damage to children's wellbeing.