720 resultados para Evelyn Silvennan


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA), Epidermal Growth Factor (EGF), and FSH. To evaluate ultrastructure of primordial follicles cultured in MEM (control) or in MEM containing IAA, EGF, and FSH, fragments of cultured tissue were processes for transmission electron microscopy. Except in the control, primordial follicles cultured in supplemented media for 6d were ultrastructurally normal. They had oocyte with intact nucleus and the cytoplasm contained heterogeneous-sized lipid droplets and numerous round or elongated mitochondria with intact parallel cristae were observed. Rough endoplasmic reticulum (RER) was rarely found. The granulosa cells cytoplasm contained a great number of mitochondria and abundant RER. In conclusion, the presence of IAA, EGF, and FSH helped to maintain ultrastructural integrity of sheep primordial follicles cultured in vitro. © 2011 Evelyn Rabelo Andrade et al.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The objective of this study was to evaluate the effects of adding ascorbic acid to the media for in vitro culture of cattle ovarian fragments and to determine their effects on growth activation and viability of early-stage follicles. The ovarian cortex was divided into small fragments; one fragment was immediately fixed (control) and the other fragments were cultured in minimum essential medium (MEM) supplemented or not with various doses of ascorbic acid. Ovarian tissue was processed for histology, transmission electron microscopy (TEM) and immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA). Compared with control fragments, the percentage of primordial follicles was reduced (p < 0.05) and the percentage of growing follicles had increased (p < 0.05) in cultured cortical fragments, independent of the tested medium or incubation time. Furthermore, compared with control tissue, culture of ovarian cortex for 8 days reduced the percentages of healthy, viable follicles (p < 0.05), but not when cultures were supplemented with 25, 50 or 100 μg/ml of ascorbic acid. Ultrastructural and immunohistochemical analysis of 8 day cultured ovarian cortical fragments, however, showed the integrity and viability of follicles only when fragments were cultured in presence of 50 μg/ml of ascorbic acid. In conclusion, this study demonstrated that addition of ascorbic acid to MEM at a concentration of 50 μg/ml not only stimulates the activation of 8 day in vitro cultured cattle primordial follicles and subsequent growth of activated follicles, but also safeguards the viability of these early-stage follicles. © 2012 Copyright Cambridge University Press.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Incluye Bibliografía

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

En este documento se dan a conocer algunos elementos que han surgido en el debate acerca de los derechos humanos de las personas mayores en el ámbito interamericano, y que seguramente también forman parte de la agenda internacional sobre el tema. La intención es comunicar a un público amplio la labor que la Organización de los Estados Americanos (OEA) está realizando para incrementar la protección y la promoción de los derechos de este grupo social.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Número especial por los 40 años de la Revista CEPAL

Relevância:

10.00% 10.00%

Publicador:

Resumo:

En el presente artículo se invita a discutir el marco conceptual y metodológico de un indicador de bienestar multidimensional, que incluye una dimensión de uso del tiempo junto con dimensiones de condiciones de vida usualmente incorporadas en este tipo de análisis. Las carencias identificadas mediante los componentes de este indicador se entienden como un obstáculo para el desarrollo de las capacidades humanas. El objetivo último es mirar más allá de las métricas monetarias e identificar los indicadores que mejor explican cómo la población, en lugar de las economías, se está desarrollando. En este análisis se emplea la metodología de identificación y agregación de Alkire y Foster (2007 y 2013) y se muestran los resultados para cuatro países de la región (Colombia, Ecuador, México y Uruguay) utilizando encuestas sobre el uso del tiempo y distinguiendo, además, por tipo de hogar.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Pós-graduação em Educação - FFC

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The leaves and thin branches of Lippia grandis Schauer, Verbenaceae, are used for flavoring of food in the Brazilian Amazon, as substitute for oregano. In this study the constituents of the essential oil were identified and the antioxidant capacity and larvicidal activity of the oil and methanol extract and its sub-fractions were evaluated. A sensory evaluation was determined in view of absence of toxicity. The oil showed a yield of 2.1% and its main constituents were thymol (45.8%), p-cymene (14.3%), γ-terpinene (10.5%), carvacrol (9.9%) and thymol methyl ether (4.8%), totalizing 85%. The DPPH radical scavenging activity showed values for the EC50 between 9.0 and 130.5 µg mL-1 and the TEAC/ABTS values varied from 131.1 to 336.0 mg TE/g, indicating significant antioxidant activity for the plant. The total phenolic content ranged from 223.0 to 761.4 mg GAE/g, contributing to the antioxidant activity observed. The crude extracts inhibited the bleaching of β-carotene and the oil showed the greatest inhibition (42.5%). The oil (LgO, 7.6±2.4 µg mL-1) showed strong larvicidal activity against the brine shrimp bioassay. The sensory evaluation was highly satisfactory in comparison to oregano. The results are very promising for the use of L. grandis in seasoning and antioxidant products.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este artigo tem como objetivo apresentar ao leitor a síntese de um estudo que compara a realidade de escolas do ensino fundamental, verificando as determinações da lei n.º 9394/96 e suas condições de aplicação envolvendo análise de dados teóricos e observações em campo empírico referentes a aspectos como aplicação de recursos financeiros, implementação de novas propostas pedagógicas, atuação de organismos multilaterais e formação profissional dos professores.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Pós-graduação em Biopatologia Bucal - ICT

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Structural health monitoring (SHM) refers to the procedure of assessing the structure conditions continuously so it is an alternative to conventional nondestructive evaluation (NDE) techniques [1]. With the growing developments in sensor technology acoustic emission (AE) technology has been attracting attention in SHM applications. AE are characterized by waves produced by the sudden internal stress redistribution caused by the changes in the internal structure, such as fatigue, crack growth, corrosion, etc. Piezoelectric materials such as Lead Zirconate Titanate (PZT) ceramic have been widely used as sensor due to its high electromechanical coupling factor and piezoelectric d coefficients. Because of the poor mechanical characteristic and the lack in the formability of the ceramic, polymer matrix-based piezoelectric composites have been studied in the last decade in order to obtain better properties in comparison with a single phase material. In this study a composite film made of polyurethane (PU) and PZT ceramic particles partially recovered with polyaniline (PAni) was characterized and used as sensor for AE detection. Preliminary results indicate that the presence of a semiconductor polymer (PAni) recovering the ceramic particles, make the poling process easier and less time consuming. Also, it is possible to observe that there is a great potential to use such type of composite as sensor for structure health monitoring.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)