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1.
J Inherit Metab Dis ; 29(2-3): 341-2, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16763897
2.
Waste Manag ; 45: 289-97, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26022338

RESUMO

Technological development and intensive marketing support the growth in demand for electrical and electronic equipment (EEE), for which printed circuit boards (PCBs) are vital components. As these devices become obsolete after short periods, waste PCBs present a problem and require recycling. PCBs are composed of ceramics, polymers, and metals, particularly Cu, which is present in highest percentages. The aim of this study was to develop an innovative method to recover Cu from the PCBs of old mobile phones, obtaining faster reaction kinetics by means of leaching with supercritical CO2 and co-solvents. The PCBs from waste mobile phones were characterized, and evaluation was made of the reaction kinetics during leaching at atmospheric pressure and using supercritical CO2 with H2O2 and H2SO4 as co-solvents. The results showed that the PCBs contained 34.83 wt% of Cu. It was found that the supercritical extraction was 9 times faster, compared to atmospheric pressure extraction. After 20 min of supercritical leaching, approximately 90% of the Cu contained in the PCB was extracted using a 1:20 solid:liquid ratio and 20% of H2O2 and H2SO4 (2.5 M). These results demonstrate the efficiency of the process. Therefore the supercritical CO2 employment in the PCBs recycling is a promising alternative and the CO2 is environmentally acceptable and reusable.


Assuntos
Dióxido de Carbono/química , Telefone Celular , Cobre/química , Resíduo Eletrônico/análise , Reciclagem/métodos , Gerenciamento de Resíduos/métodos , Peróxido de Hidrogênio/análise , Ácidos Sulfúricos/análise
3.
Hum Mol Genet ; 14(18): 2695-703, 2005 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16115821

RESUMO

Inherited defect in very-long-chain acyl-CoA dehydrogenase (VLCAD), a mitochondrial enzyme catalyzing the initial step of long-chain fatty acid beta-oxidation (FAO), is one of the most frequent FAO enzyme defects. VLCAD deficiency is associated with clinical manifestations varying in severity, tissue involvement and age of onset. The molecular basis of VLCAD deficiency has been elucidated but therapeutic approaches are quite limited. In this study, we tested the hypothesis that fibrates, acting as agonist of peroxisome proliferator-activated receptors (PPARs), might stimulate FAO in VLCAD-deficient cells. We demonstrate that addition of bezafibrate or fenofibric acid in the culture medium induced a dose-dependent (up to 3-fold) increase in palmitate oxidation capacities in cells from patients with the myopathic form of VLCAD deficiency, but not in cells from severely affected patients. Complete normalization of cell FAO capacities could be achieved after exposure to 500 microm bezafibrate for 48 h. Cell therapy of VLCAD deficiency was related to drug-induced increases in VLCAD mRNA (+44 to +150%; P<0.001), protein (1.5-2-fold) and residual enzyme activity (up to 7.7-fold) in patient cells. Bezafibrate also diminished the production of toxic long-chain acylcarnitines by 90% in cells harboring moderate VLCAD deficiency. Finally, real-time PCR studies indicated that bezafibrate potentially stimulated gene expression of other enzymes in the beta-oxidation pathway. These data highlight the potential of fibrates in the correction of inborn FAO defects, as most mutations associated with these defects are compatible with the synthesis of a mutant protein with variable levels of residual enzyme activity.


Assuntos
Acil-CoA Desidrogenase de Cadeia Longa/deficiência , Acil-CoA Desidrogenase de Cadeia Longa/metabolismo , Bezafibrato/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Erros Inatos do Metabolismo Lipídico/tratamento farmacológico , RNA Mensageiro/metabolismo , Acil-CoA Desidrogenase de Cadeia Longa/genética , Bezafibrato/uso terapêutico , Western Blotting , Carnitina/análogos & derivados , Carnitina/metabolismo , Primers do DNA , Relação Dose-Resposta a Droga , Fibroblastos , Humanos , Erros Inatos do Metabolismo Lipídico/genética , Erros Inatos do Metabolismo Lipídico/metabolismo , Mitocôndrias/enzimologia , Mutação de Sentido Incorreto/genética , Palmitatos/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/antagonistas & inibidores , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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