Toxic effects of dietary of Al3+ ions in tilapias (Oreochromis niloticus) and protective effect of Zn2+ ion

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The lethal effects of aluminum ion (Al3+) in tilapia (Oreochromis niloticus) raised in concrete tanks were investigated. Tilapias were fed daily with commercial feed enriched with known concentrations of Al3+ and analyzed by differential pulse anodic stripping voltammetry (DPASV). The concentrations of Al3+ in feces, water, muscle tissue, viscera, and heads were determined every 3 months for a period of 365 days. The Tilapia head was the most affected tissue by Al3+. In general, Al3+ bioaccumulation reached the lethal dose (LD50) after 335 days of experiment as follows: 34.9 mg kg(-1) (muscle tissue), 88.2 mg kg(-1) (viscera), and 126.9 mg kg(-1) (head without gills). After determining Cu2+, Zn2+, and Ca2+ by absorption spectrometry, a decrease in the Ca2+ concentration was noted in the head during the experimental period. These observations were associated with the occurrence of a decalcification in the bone tissue in the presence of Al3+. In contrast, it was found that Zn2+ ions may act as a protective agent against Al3+-induced contamination.93192101Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effect of magnetite on the adsorption behavior of Pb(II), Cd(II), and Cu(II) in chitosan-based hydrogels

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)In the present investigation, a chitosan-based hydrogel, graft-copolymerized with methylenebisacrylamide and poly(acrylic acid), (i.e., CS-co-MMB-co-PAA), was employed in studies on the adsorption kinetics of Pb (II), Cd(II), and Cu(II) ions in aqueous solution. Swelling studies performed using the Fickian diffusion model inferred that the mass transfer mechanism of water in hydrogels was governed by diffusion and macromolecular structural relaxation, modified by the presence of magnetite. The best parameters for the removal of metals were pH between 4.5 and 5.5, initial metal concentration of 300 mg dm(-3) and 100 mg of dried hydrogel mass. Isotherm models of Langmuir, Freundlich and Redlich-Peterson suggest that there may be variation in the physicochemical phenomena involving metal adsorption. These isotherms reveal that the adsorption efficiency decreased in the presence of magnetite. Hydrogels with magnetite and the metal ions adsorbed on them may be recovered after the application of an external magnetic field, as opposed to the hydrogels without magnetite, which are frequently recovered using a chemical solvent. The recovery of adsorbents by applying external ac or dc magnetic fields in the absence of solvent is an environmentally clean alternative, with no production of a secondary waste. (C) 2011 Elsevier By. All rights reserved.27541699187196Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [2008/00285-7]CAPES [5267/09-9

Medication report reduces number of medication errors when elderly patients are discharged from hospital

Objective To investigate whether a Medication Report can reduce the number of medication errors when elderly patients are discharged from hospital. Method We conducted a prospective intervention with retrospective controls on patients at three departments at Lund University Hospital, Sweden that where transferred to primary care. The intervention group, where patients received a Medication Report at discharge, was compared with a control group with patients of the same age, who were not given a Medication Report when discharged from the same ward one year earlier. Main outcome measures The main outcome measure was the number of medication errors when elderly patients were discharged from hospital. Results Among 248 patients in the intervention group 79 (32%) had at least one medication error as compared with 118 (66%) among the 179 patients in the control group. In the intervention group 15% of the patients had errors that were considered to have moderate or high risk of clinical consequences compared with 32% in the control group. The differences were statistically significant (P < 0.001). Conclusion Medication errors are common when elderly patients are discharged from hospital. The Medication Report is a simple tool that reduces the number of medication errors

Internal and external restructuring over the cycle: a firm-based analysis of gross flows and productivity growth in Portugal

Cleansing, Active and passive learning, Internal restructuring, External restructuring, Productivity growth, L60, L11, O47, O12,