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1.
Environ Sci Technol ; 53(24): 14528-14537, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31730354

RESUMO

This study investigated the degradation of perfluorooctanesulfonate (PFOS) in a reactive electrochemical membrane (REM) system in which a porous Magnéli phase titanium suboxide ceramic membrane served simultaneously as the anode and the membrane. Near complete removal (98.30 ± 0.51%) of PFOS was achieved under a cross-flow filtration mode at the anodic potential of 3.15 V vs standard hydrogen electrode (SHE). PFOS removal efficiency during the REM operation is much greater than that of the batch operation mode under the same anodic potential. A systematic reaction rate analysis in combination with electrochemical characterizations quantitatively elucidated the enhancement of PFOS removal in REM operation in relation to the increased electroactive surface area and improved interphase mass transfer. PFOS appeared to undergo rapid mineralization to CO2 and F-, with only trace levels of short-chain perfluorocarboxylic acids (PFCAs, C4-C8) identified as intermediate products. Density functional theory (DFT) simulations and experiments involving free radical scavengers indicated that PFOS degradation was initiated by direct electron transfer (DET) on anode to yield PFOS free radicals (PFOS•), which further react with hydroxyl radicals that were generated by water oxidation and adsorbed on the anode surface (•OHads). The attack of •OHads is essential to PFOS degradation, because, otherwise, PFOS• may react with water and revert to PFOS.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Poluentes Químicos da Água , Técnicas Eletroquímicas , Eletrodos , Oxirredução , Titânio
2.
Nutr Cancer ; 52(2): 121-9, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16201843

RESUMO

We present a case of a 78-yr-old man with malignant fibrous histiocytoma with multiple lesions in both lungs. Following diagnosis, he declined conventional chemotherapy and elected nutritional intervention by increasing intake of omega-3 fatty acids and lowering intake of omega-6 fatty acids. We estimated that he consumed 15 g of the long-chain omega-3 fatty acids eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) per day, and the ratio of linoleic acid/long-chain omega-3 fatty acids in his diet was 0.81. Serial computed tomography scans and pulmonary x-rays revealed remarkably a slow and steady decrease in the size and number of bilateral nodules. He has no apparent side effects from consuming large quantities of fish and algae oils rich in DHA and EPA and he remains asymptomatic.


Assuntos
Ácidos Graxos Ômega-3/uso terapêutico , Histiocitoma Fibroso Maligno/dietoterapia , Neoplasias Pulmonares/dietoterapia , Idoso , Progressão da Doença , Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácido Eicosapentaenoico/uso terapêutico , Óleos de Peixe , Histiocitoma Fibroso Maligno/patologia , Humanos , Neoplasias Pulmonares/patologia , Masculino
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