Ministry of Agriculture

About: Ministry of Agriculture is a government organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Chemistry & Salmonella. The organization has 1153 authors who have published 1189 publications receiving 14442 citations.

Effects of Space Mission Factors on the Morphology and Function of Endothelial Cells

Abstract: The structure and functions of endothelial cells after space mission were studied by electron and laser confocal microscopy, image analysis, and MTT test. The endothelial cells changed significantly (proliferative activity, size, contours, shape, distribution of mitochondria and microtubules) in comparison with controls on the Earth. These changes indicated injuries in the cytoskeleton and impairment of the barrier function of the cells, which presumably contributed to the development of endothelial dysfunction.

Manual breast pump

Abstract: The invention relates to a breast pump for pumping mother's milk, said pump comprising a cylindrical hollow piston (1) provided with at least one outer peripheral recess (6) on the lower end in relation to the cylindrical envelope surface of the hollow piston, a vacuum extractor (2) which is connected to the upper end of the hollow piston by means of a fluid passage (3), a flexible compensation element (8) arranged between the hollow piston and the abutment surface of the vacuum extractor, at least one peripheral sealing element (14) consisting of a flexible material and inserted into the recess, and a cylinder (18) having a closed lower end in which the hollow piston can move axially. The envelope surface of the hollow piston is guided on an inner wall of the cylinder, the sealing element is arranged between the inner wall of the cylinder and the hollow piston in a sealing manner, and at least the vacuum extractor is arranged outside the cylinder.

Sequential factorial designs for method development of the determination of Cd and Pb in fish and shrimp by GF AAS after sample freeze-drying and tetramethylammonium hydroxide solubilization

Abstract: The development and validation of a simple, reliable and fast method for the determination of cadmium and lead in fish and shrimp by GF AAS, following sample freeze-drying and tetramethylammonium hydroxide (TMAH) solubilization, is presented. The method development was achieved by sequentially applying factorial designs until optimization within the bilinear approximation of the method was accomplished. As such, seven experimental parameters were initially studied, which were considered important for the determination of cadmium and lead in seafood samples using TMAH solubilization. The validation of the method was completed in order to comply with international food regulations and method accreditation under ISO 17025. In this sense, the following parameters were evaluated: linearity, limits of detection and quantification, precision, recovery (trueness), specificity and robustness. Linearity of response was satisfactory for the concentration ranges of both analytes. The residuals for both elements were homoscedastic and independent, with normal distributions. Limits of quantification (LOQ), based on signal standard deviation for low-in-cadmium and lead samples, were 6.25 μg kg−1 and 31.25 μg kg−1, respectively. These figures are in accordance with performance criteria required by the Commission Regulation (EU) no 836/2011. The repeatability of the method, calculated from the analysis of seven sample replicates at two concentration levels of cadmium and lead, by the same analyst, was usually better than 10%. Recovery was estimated from the repeatability evaluation, lying in the range of 84% to 99% for cadmium, and 94% to 107% for lead. Furthermore, a wide evaluation of the method robustness was performed during the method optimization. Thus, the results showed the suitability of the developed method for the determination of Cd and Pb in fish and shrimp by GF AAS, following TMAH solubilization for food control purposes. Additionally, the use of sequential factorial designs in order to achieve bilinear optimization of the method was proven to be a very valuable tool, by sharply reducing optimization time and the number of experiments.

Eficiência de um kit de ELISA na detecção e quantificação de aflatoxina M1 em leite e investigação da ocorrência no estado de Minas Gerais

Abstract: Procedures for intralaboratory validation of an ELISA kit were adopted to verify its efficiency in aflatoxin M1 detection and quantification in milk. Assays were accomplished with standard solutions provided with the kit, spiked samples and naturally contaminated samples. The mean recovery values obtained for the kit standard solutions were between 85.6 and 114.8%, with coefficient of variation ranging from 11.6 to 23.1%. Working with spiked samples, a concentration range for quantitative analysis (0.019 to 0.090µg/L) was defined. The occurrence of aflatoxin M1 in 110 milk samples from the State of Minas Gerais was investigated. Five of the 27 positive samples in the screening for ELISA were confirmed by thin layer chromatography.