RESUMO
Room temperature depositions of barium on a thermal silicon oxide layer were performed in ultra high vacuum (UHV). In-situ X-ray photoelectron spectroscopy (XPS) analyses were carried out as well after exposure to air as after subsequent annealings. These analyses were ex-situ completed by secondary ion mass spectrometry (SIMS) profiles and transmission electron microscopy (TEM) cross-sectional images. The results showed that after air exposure, the barium went carbonated. Annealing at sufficient temperature permitted to decompose the carbonate to benefit of a barium silicate. The silicate layer was formed by interdiffusion of barium with the initial SiO2 layer.
RESUMO
1. Histamine was detected in the abdominal aorta and the femoral arteries of normotensive and also DOCA-hypertensive rats. 2. Levels of total histamine (mast cell and non-mast cell histamine) were significantly reduced in both abdominal aorta and the femoral artery of the DOCA-hypertensive rats, relative to the normotensive controls. 3. It is suggested that the diminished level of vascular histamine may be related to the development and/or maintenance of the hypertensive state and is also related to the reduced magnitude of active reflex vasodilatation.