RESUMO
The impact of human activity on the sediments of Todos os Santos Bay in Brazil was evaluated by elemental analysis and 13C Nuclear Magnetic Resonance (13C NMR). This article reports a study of six sediment cores collected at different depths and regions of Todos os Santos Bay. The elemental profiles of cores collected on the eastern side of Frades Island suggest an abrupt change in the sedimentation regime. Autoregressive Integrated Moving Average (ARIMA) analysis corroborates this result. The range of depths of the cores corresponds to about 50 years ago, coinciding with the implantation of major onshore industrial projects in the region. Principal Component Analysis of the 13C NMR spectra clearly differentiates sediment samples closer to the Subaé estuary, which have high contents of terrestrial organic matter, from those closer to a local oil refinery. The results presented in this article illustrate several important aspects of environmental impact of human activity on this bay.
Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Espectroscopia de Ressonância Magnética/métodos , Compostos Orgânicos/análise , Poluentes Químicos da Água/análise , Brasil , Carbono/análise , Sedimentos Geológicos/química , Humanos , Nitrogênio/análise , Água do Mar/análise , Água do Mar/química , Enxofre/análiseRESUMO
In this work we report on a study of the morphological changes of LDL induced in vitro by metallic ions (Cu(2+) and Fe(3+)). These modifications were characterized by transmission electron microscopy, nuclear magnetic resonance and the Z-scan technique. The degree of oxidative modification of LDL was determined by the TBARS and lipid hydroperoxides assays. It is shown that distinct pathways for modifying lipoproteins lead to different morphological transformations of the particles characterized by changes in size and/or shape of the resulting particles, and by the tendency to induce aggregation of the particles. There were no evidence of melting of particles promoted by oxidative processes with Cu and Fe.
Assuntos
Cobre/química , Ferro/química , Lipoproteínas LDL/química , Cátions/química , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Oxirredução , Substâncias Reativas com Ácido Tiobarbitúrico/químicaRESUMO
In this work we report on a study of the morphological changes of LDL induced in vitro by metallic ions (Cu2+ and Fe3+). These modifications were characterized by transmission electron microscopy, nuclear magnetic resonance and the Z-scan technique. The degree of oxidative modification of LDL was determined by the TBARS and lipid hydroperoxides assays. It is shown that distinct pathways for modifying lipoproteins lead to different morphological transformations of the particles characterized by changes in size and/or shape of the resulting particles, and by the tendency to induce aggregation of the particles. There were no evidence of melting of particles promoted by oxidative processes with Cu and Fe.
