Microstructure of organometallic derived PLZT ceramics

The PLZT powders with the formula Pb0.905La0.095(Zr0.65Ti0.35)(0.976)O-3+3.5 wt.% PbO were prepared by the organometallic precursor method (Pechini and partial oxalate processes). The microstructure of sintered 9.5/65/35 PLZT ceramics obtained from a partial oxalate procedure shows that the outstanding feature of this microstructure is its fairly uniform grains of about 1.8 mum. The microstructure of sintered PLZT ceramics obtained by the Pechini process consists of uniform small randomly- oriented grains tightly bonded together in the central part of the sample with,a grain size of about 1.2 mum. Cubic and elongated grains are formed at the sample's border. The microstructures of hot pressed PLZT ceramics obtained from both processes are dense and rather uniform. After a double stage of hot pressing (2 plus 20 h) the microstructure of PLZT is fully dense, uniform and homogeneous with a grain size of approximately 2.5 mum. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Central nifedipine-induced alterations in salivary flow and compounds: Role of nitric oxide

The aim of this study was to examine the role of nifedipine and Nitric Oxide (NO) on salivary flow and compounds (salivary amylase, saliva total proteins, saliva calcium, sodium and potassium). Male Holtzman rats weighting 200-250 g were anesthetized with zoletil 50 mg kg -1 (tiletamine chloridrate 125.0 mg and zolazepan chloridrate 125.0 mg) into quadriceps muscle and stainless steel cannulas were implanted into their lateral ventricle of the brain (LV). Animals in divided group were injected with nifedipine (50 μg μL -1) alone and in combination with 7-nitroindazol (7-NIT) (40 μg μL -1), neuronal NO Sinthase Inhibitor (nNOSI) and Sodium Nitroprussate (SNP) (30 μg μL -1) NO donor agent. As a secretory stimuli, pilocarpine dissolved in isotonic was administered intraperitoneally (ip) at a dosage of 10 mg kg -1 body weight. Saliva was collected for 7 min with four cotton balls weighing approximately 20 mg each, two of which were placed on either side of the oral cavity, with the other two placed under the tongue. Nifedipine treatment induced a reduction in saliva secretion rate and concentration of amylase, total protein and calcium without changes in sodium and potassium concentration in comparison with controls. Co-treatment of animals with nifedipine and SNP retained flow rate and concentration of amylase, total protein and calcium in normal levels. Co-treatment of animals with nifedipine and 7-NIT potentiated the effect of nifedipine on the reduction of saliva secretion and concentrations of amylase, total protein and calcium. Nifedipine (dihydroperidine) calcium-channel blocker widely in use is associated with salivary dysfunction acting in the central nervous system structures. NO might be the mechanism for protective effect against the nifedipine-induce salivary dysfunction, acting in the CNS. © 2006 Asian Network for Scientific Information.

Committees for ethics in research involving human subjects

In Brazil since October 1996 there have been guidelines for research involving human subjects. Now human subjects know when their treatment is part of research. Deceit is no longer tolerated. But is not enough to say we offer an explanation to the potential subject and we offer a choice before he or she is confronted with an informed consent form. As in all professional activity, scientific investigation needs social controls. In Brazil, the ultimate responsibility of an investigation lies on the investigator, but in every institution where research is carried out there is a Committee for Ethics in Research. All Committees are subordinated to the National Commission of Ethics in Research, which is submitted to the Brazilian Institute of Health. During 2005 around 17,000 protocols involving 700,000 human subjects were revised by 475 Committees distributed all over the country. Approximately 7,000 people are now working in these Committees.

Agricultural incentives, growth and poverty in Latin America and the Caribbean: cross-country evidence for the period 1960-2005. Did trade liberalization increase the incomes of the poorest?

Includes bibliography

Guatemala, censo experimental de 1970: aplicacion de las tecnicas del profesor William Brass para estimar la fecundidad y la mortalidad

Incluye Bibliografía

Costa Rica (Canton Grecia) 1968 y Chile 1960: algunas consideraciones del metodo del profesor William Brass para estimar fecundidad

Incluye Bibliografía

Cuatro lecciones de William Brass

Conferencias dictadas por el profesor Brass en visita a CELADE, 2-5 noviembre 1975

Aplicaciones de los metodos para estimar la cabalidad de los registros a partir de la distribucion por edades de las muertes: a).de William Brass; b).de Samuel Preston; resumen del estudio

A la informacion sobre la distribucion por edades en las muertes registradas a partir de la edad de 5 anos en Chile, Costa Rica, Guatemala, Panama y Peru, se aplican los dos metodos propuestos para evaluar la cabalidad de los registros de defunciones. Los resultados obtenidos de aplicar estos metodos se presentan en graficos y cuadros, con aplicaciones hechas en los 5 paises

Bolivia: estimacion de la mortalidad a partir de la distribucion por edades de las muertes, 1951. Metodo de William Brass

Incluye Bibliografía

Costa Rica: estimacion de la mortalidad masculina adulta a partir de la orfandad de padre por medio de tecnicas de William Brass

Incluye Bibliografía

Determinacion de la mortalidad por medio de las tecnicas de William Brass, con especial referencia al sistema logito

Incluye Bibliografía

Peru: comprobacion del metodo de William Brass sobre la estimacion del nivel de la mortalidad en 1940, a partir de la proporcion: hijos sobrevivientes

Incluye Bibliografía

Dissolução e aleatoriedade: a estética do romance na obra Almoço nu de William S. Burroughs. -

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)