Risk factors associated with the antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis.

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Sisal Fibers Treated with NaOH and Benzophenonetetracarboxylic Dianhydride as Reinforcement of Phenolic Matrix

In this work, composites based on a phenolic matrix and untreated- and treated sisal fibers were prepared. The treated sisal fibers used were those reacted with NaOH 2% solution and esterified using benzophenonetetracarboxylic dianhydride (BTDA). These treated fibers were modified with the objective of improving the adhesion of the fiber-matrix interface, which in turn influences the properties of the composites. BTDA was chosen as the esterifying agent to take advantage of the possibility of introducing; the polar and aromatic groups that are also present in the matrix structure into the surface of the fiber, which could then intensify the interactions occurring in the fiber-matrix interface. The fibers were then analyzed by SEM and FTIR to ascertain their chemical composition. The results showed that the fibers had been successfully modified. The composites (reinforced with 15%, w/w of 3.0 cm length sisal fiber randomly distributed) were characterized by SEM, impact strength, and water absorption capacity. In the tests conducted, the response of the composites was affected both by properties of the matrix and the fibers, besides the interfacial properties of the fiber-matrix. Overall, the results showed that the fiber treatment resulted in a composite that was less hygroscopic although with somewhat lower impact strength, when compared with the composite reinforced with untreated sisal fibers. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 269-276, 2010CNPq (National Research Council, Brazil)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP (The State of Sao Paulo Research Foundation, Brazil

Mercury levels in feed and muscle of farmed tilapia.

Background Fish consumption is considered the most important source of contaminant exposure for humans beings, and farmed fish can be exposed to contaminants via feed supply. Methods Total mercury concentrations (THg) were determined in the muscle, liver, and feed of farmed Nile tilapia (juveniles and adults) from four different fish farms in Brazil (net cages and intensive tanks systems), by a flow injection mercury system. Results Mercury concentrations observed in fish muscle were markedly lower (13.530.5?mu g?kg-1) than the values recommended by ANVISA/MAPA for edible part of fish (500?mu g?kg-1), and in the liver the concentrations found were higher than in the muscle. Conclusions These low levels of THg in farmed tilapia may be due to the low THg concentrations found in the analyzed fish feed, that ranged from 5.2 to 33.2?mu g?kg-1, below the limit of 100?mu g?kg-1 established by the European Commission