964 resultados para acidification
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The zero-valent iron (ZVI) mediated degradation of the antibiotic ciprofloxacin (CIP) was studied under oxic condition. Operational parameters such as ZVI concentration and initial pH value were evaluated. Increase of the ZVI concentration from 1 to 5 g L−1 resulted in a sharp increase of the observed pseudo-first order rate constant of CIP degradation, reaching a plateau at around 10 g L−1. The contribution of adsorption to the overall removal of CIP and dissolved organic carbon (DOC) was evaluated after a procedure of acidification to pH 2.5 with sulfuric acid and sonication for 2 min. Adsorption increased as pH increased, while degradation decreased, showing that adsorption is not important for degradation. Contribution of adsorption was much more important for DOC removal than for CIP. Degradation of CIP resulted in partial defluorination since the fluoride measured corresponded to 34% of the theoretical value after 120 min of reaction. Analysis by liquid chromatography coupled to mass spectrometry showed the presence of products of hydroxylation on both piperazine and quinolonic rings generating fluorinated and defluorinated compounds as well as a product of the piperazine ring cleavage.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Medicina Veterinária - FMVZ
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The objective of this study was to evaluate the prevalence of urinary metabolic abnormalities in patients with urolithiasis and their potential risk factors.A total of 905 stone patients were evaluated in a prospective trial from February 2000 to January 2012. Inclusion criteria were as follows: history and/or imaging tests confirming at least 2 separate or concurrent stone episodes; creatinine clearance a parts per thousand yen60 mL/min; and negative proteinuria and urine culture. Metabolic study consisted of two 24-h urine collections separated by a period of 3 months for dosing Ca, P, uric acid, Na, K, Mg, oxalate, and citrate. Serum levels of Ca, P, uric acid, Na, K, Cl, Mg, creatinine, and glucose were assessed. Urinary pH and urinary acidification tests were also performed.A total of 735 patients were included, with a mean age of the 40 +/- A 1.0 year; 96.8 % of patients presented diagnosis of one or more urinary metabolic abnormalities. The most prevalent metabolic abnormalities were hypercalciuria (50.8 %), hypomagnesuria (50.1 %), hypocitraturia (35.4 %), and hyperuricosuria (30.7 %). Body weight was significantly higher in patients with hyperuricosuria (81.20 +/- A 15.67 kg vs. 70.17 +/- A 14.13 kg, respectively, p = 0.001). Urinary sodium was significantly higher in patients with hypercalciuria than without (246.97 +/- A 103.9 mEq/24 h vs. 200.31 +/- A 91.6 mEq/24 h, p = 0.001) and hyperuricosuria compared to without (283.24 +/- A 107.95 mEq/24 h vs. 198.57 +/- A 85.3 mEq/24 h, p = 0.001).Urinary metabolic disturbances were diagnosed in 96.8 % of patients in the study. These results warrant metabolic study and follow-up in patients with recurrent lithiasis in order to decrease recurrence rate through specific treatments, modification in alimentary, and behavioral habits.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Engenharia Civil e Ambiental - FEB
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Calcium carbonate production by marine organisms is an essential process in the global budget of CO32-, and coralline reefs are the most important benthic carbonate producers. Crustose coralline algae (CCA) are well recognized as the most important carbonate builders in the tropical Brazilian continental shelf, forming structural reefs and extensive rhodolith beds. However, the distribution of CCA beds, as well as their role in CO32- mineralization in mesophotic communities and isolated carbonate banks, is still poorly known. To characterize the bottom features of several seamount summits in the Southwestern Atlantic (SWA), side-scan sonar records, remotely operated vehicle imagery, and benthic samples with mixed-gas scuba diving were acquired during two recent research cruises (March 2009 and February 2011). The tops of several seamounts within this region are relatively shallow (similar to 60 m), flat, and dominated by rhodolith beds (Vitoria, Almirante Saldanha, Davis, and Jaseur seamounts, as well as the Trindade Island shelf). On the basis of abundance, dimensions, vitality, and growth rates of CCA nodules, a mean CaCO3 production was estimated, ranging from 0.4 to 1.8 kg m(-2) y(-1) with a total production reaching 1.5 x 10(-3) Gt y(-1). Our results indicate that these SWA seamount summits provide extensive areas of shallow reef area and represent 0.3% of the world's carbonate banks. The importance of this habitat has been highly neglected, and immediate management needs must be fulfilled in the short term to ensure long-term persistence of the ecosystem services provided by these offshore carbonate realms.
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The jucara's palm (Euterpe edulis), native to the Atlantic Forest is one of the palms most exploited for the removal of heart palm and the tree was removed in large areas. The aim of this study was to examine the feasibility of the methodology of "minimally processed" in jucara's palm. The raw material was obtained by COOPERAGUA, Sete Barras (SP) through a Sustainable Management Plan culminating in a permit issued by IBAMA, Forestry Foundation and DPRN. The process began with the withdrawal of external sheaths and cut, with subsequent immersion in a solution of sodium metabisulphite (Na2S2O5 - 200 ppm), sanitize with a chlorine solution and soak in brine acidified to wait until the filling. The cuttings were placed in polyethylene bags containing acidified solution at concentrations A 0.225%, B 0.375%, C 0.6%, D 0.825% determined by titration curve. The staining became clearer in treatments C and D, due to more acidity, resulting in higher inactivation of enzymes. Even with these positive results, were concluded that minimal processing of jucara is not effective due to the blackout, preventing its commercialization. To stop it requires the bleaching step, which does not characterize it as minimally processed.