The proliferating cell nuclear antigen index in breast carcinomas does not correlate with mitotic index and estrogen receptor immunoreactivity

To investigate the expression of a marker of cell proliferation (PCNA/Cyclin) and its putative relationship with histological grading, mitotic index and estrogen receptor immunoreactivity, we studied twenty-seven cases of invasive breast carcinoma in formalin-fixed, paraffin-embedded tissue sections. The PCNA and estrogen receptor were detected by the PC10 and H222 monoclonal antibodies respectively, using an avidin-biotin-pernxidase method. The median value of PCNA index was 20.9% with a range from 1.4 to 84.2%. We did not find any significant relationship between PCNA index anti the histological grading, mitotic index and estrogen receptor immunoreactivity. We conclude that PCNA detected by the monoclonal antibody PC10 in formalin-fixed material looks at present unrealiable as a proliferation marker in breast carcinoma.

Isolation and chemical characterization of PwTx-II: A novel alkaloid toxin from the venom of the spider Parawixia bistriata (Araneidae, Araneae)

Brazil has many species of spiders belonging to Araneidae family however, very little is known about the composition, chemical structure and mechanisms of action of the main venom components of these spiders. The main objective of this work was to isolate and to perform the chemical characterization of a novel beta-carboline toxin from the venom of the spider Parawixia bistriata, a typical species of the Brazilian 'cerrado'. The toxin was purified by RP-HPLC and structurally elucidated by using a combination of different spectroscopic techniques (UV, ESI-MS/MS and H-1 NMR), which permitted the assignment of the molecular structure of a novel spider venom toxin, identified as 1-4-guanidinobutoxy-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline, and referred to here as PwTx-II. This compound is toxic to insects (LD50 = 12 +/- 3 eta g/mg honeybee), neurotoxic, convulsive and lethal to rats (LD50 = 9.75 mg/kg of male Wistar rat). (c) 2005 Elsevier Ltd. All rights reserved.

Investigation of the cytocidal potential of Rhinella jimi skin methanol extracts

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Introduction: The Brazilian atlantic forest

The year 2000 marks 500 years of massive destruction for the Brazilian Atlantic Forest, as a consequence of the European colonization of Brazil. Today, the Atlantic Forest is restricted to ca 98,800 km2 of remnants, or 7.6 percent of its original extension. The Atlantic Forest continues to suffer under severe anthropogenic pressure, risking imminent extinction of the remaining species. Our current knowledge indicates that this complex biome contains a species diversity higher than most of the Amazon forests, and also has high levels of endemism. The 13 selected articles in this special issue present data on the natural history, ecology, sustainable management, and conservation of the Atlantic Forest. These articles represent a sample of the research conducted to date in the region and suggest avenues of future research, particularly with regard to conservation alternatives for the remaining portions of the Atlantic Forest. This special issue represents one of the first general references pertaining to the Brazilian Atlantic Forest.

Borohidreto complexos de cobre (I) contendo difosfinas. Caracterização espectroscópica e comportamento térmico

Tetrahydroborate complexes of copper (I) with bidentate phosphines, [Cu(η 2-BH 4)(dppm)] (1), [Cu(η 2-BH 4)(dppe)] (2), [Cu(η 2-BH 4)(cis-dppet)] (3) and [Cu(η 2-BH 4)(dppb)] (4) (dppm = bis(diphenylphosphino)methane; dppe = 1,2-bis(diphenylphosphino) ethane; cis-dppet = 1,2-cis(diphenylphosphino)ethene; dppb = 1,4-bis(diphenylphosphino)butane) were prepared and characterized by elemental analysis, infrared spectroscopy, NMR and thermogravimetric analysis. The IR data for 1-4 showed bands typical of a bidentate coordination of BH 4 group to the copper atom and the 31P{ 1H} NMR spectra indicated that the phosphorous atoms are chelating the metal centre. The thermal behavior of the compounds was investigated and suggested that their thermal stability is influenced by the phosphines. Their thermal stability decreased as follows: [Cu(η 2-BH 4)(dppe)] (2) > [Cu(η 2-BH 4)(dppm)] (1) > [Cu(η 2-BH 4)(dppb)] (4) > [Cu(η 2-BH 4)(cis-dppet)] (3). According to thermal analysis and X-ray diffraction patterns all compounds decomposed giving Cu(BO 2) 2, CuO, CuO 2 and Cu as final products.

Estimativa da exigência hídrica do amendoim usando um modelo agrometeorológico

In the experimental area of the Department of Environmental Sciences (21.85° S; 48.43° W; 786 m), in the School of Agronomical Sciences, UNESP, Botucatu, SP, an experiment was carried out using peanut (Arachis hypogaea L), cv. IAC-TATU-ST, to quantify the crop daily water requirements. During the peanut crop cycle, the environmental variables, such as rainfall, air temperature, air relative humidity, soil matric potential, soil heat flux and radiation balance, have been registered continually. These measurements were used to calculate the daily crop evapotranspiration, by the Bowen ratio method. The water replacement required by the peanut crop was done the dripping irrigation system, oriented by a dynamic agrometeorological model that computes the entrance and exit of water in the soil. During the peanut crop cycle, 9.0 mm of water was used from sowing to emergence; 67.0 mm of water, in the growth stage; 166.0 mm, in the flowering stage; 124.0 mm in the final stage and 46.0 mm from physiological maturity to harvest. Oot of 412.0 mm of the total consumption, 246.0 mm of water was supplied by irrigation and 166.0 mm by the rain. The grain yield was 3.15 t ha-1 for 15% of humidity, and the water use efficiency was 0.764 kg m-3.

Competencia y regulación de la banca: el caso de Panamá

Incluye Bibliografía

Tax evasion: causes, estimation methods, and penalties: a focus on Latin America

Includes bibliography

Estimates of hourly diffuse radiation on tilted surfaces in southeast of brazil

The global radiation incident on a tilted surfaces consists of components direct, diffuse and reflected from the ground. On a hourly database, the direct radiation can be calculated by geometric projections (ratio of the incidence angle to the solar zenith angle). The reflected radiation has a small effect on calculations and may be calculated with an isotropic model. Both components presents dependence of measures in incidence or horizontal surface. The great difficulty is to evaluate the diffuse radiation by variations of circumsolar, brightness horizontal, isotropic and anisotropic subcomponents. This study evaluated twenty models to estimate hourly diffuse radiation incident on tilted surfaces at 12.85° (latitude - 10°), 22.85° (latitude) and 32.85° (latitude + 10°) facing to North, under different cloudiness sky conditions, in Botucatu, São Paulo State, Brazil (22°53' S, 48°26' W and 786 m above the mean sea level). In contrast, models for estimating the diffuse component show major differences, which justify the validation for local calibrations. There is a decrease of the maximum total radiation scattered with increasing atmospheric transmissivity and inclination angle. The best results are obtained by anisotropic models: Ma and Iqbal, Hay, Reindl et al. and Willmott; isotropic: Badescu and Koronakis, and the Circumsolar model. The increase of the inclination angle allows for a reduction in the performance of statistical parametric models for estimating the hourly diffuse radiation.

Centroamérica: estadísticas del subsector eléctrico, 2009

Incluye bibliografía

Avaliação da eficiência do amendoim (Arachis hypogaea L.) na utilização da radiação fotossinteticamente ativa para produção de matéria seca

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Propuesta para crear la empresa de promoción y comercialización intrarregional de productos e insumos del sector minero-metalúrgico de América Latina y el Caribe

Incluye Bibliografía

Resistência de genótipos de feijão-caupi Vigna unguiculata a Bemisia tabaci Biótipo B (Hemiptera: Aleyrodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)