Oxidative Stress and Disease

Typically in aerobic metabolism, organic compounds such as nucleic acids, proteins and lipids can undergo structural damage by oxidative reactions. This damage caused by reactive oxygen/nitrogen species has been recognized as “oxidative stress”. Despite the biological systems present efficient enzymatic and nonenzymatic antioxidant systems, oxidative stress indicates a pro-oxidant/antioxidant imbalance in favor of excessive generation of free radicals or decrease in the removal rate. Various diseases such as cancer, diabetes, cardiovascular diseases and neurodegenerative clearly exemplify the chronic oxidative stress. Therefore, it is important to consider that at low and moderate ROS levels, it can, for example, act as signaling molecules that support cell proliferation and differentiation and activate survival pathways in response to stress. Correlations between oxidative stress and disease should be carefully investigated in order to understand whether oxidative stress actually increases susceptibility to a particular disease or opposite

A LEGISLAÇÃO BRASILEIRA E SUA ADEQUAÇÃO A REALIDADE NA PROTEÇÃO AMBIENTAL DAS CHAPADAS: REFLEXÕES INICIAIS

A vegetação em áreas de borda de chapada é de grande importância ambiental, sendo consideradas como Área de Preservação Permanente. Este trabalho se baseou em revisão bibliográfica e objetivou verificar se o conceito legal de chapada é coerente com o científico. Os resultados apontam que a legislação não é clara quanto à classificação deste tipo de relevo e as características exigidas fazem com que as geoformas que cientificamente poderiam ser consideradas como chapadas, legalmente não o seja

Determination of 5-fluorouracil in surface samples using SPE combined with HPLC- DAD

A simple and rapid SPE-HPLC-DAD method was developed for the determination of 5-fluorouracil (5-FU) in surface samples. A C18 column (250 x 4.6 mm i.d., 5 µm) and a similar pre-column were used for the separation at 25 ºC, using 20 mM ammonium acetate buffer solution pH 4.7: methanol (95:5, v/v) as mobile phase at a flow rate of 1.2 mL/min. Under optimal conditions, the linearity was 0.9993, in a range of 25-100 µg/mL. The limits of detection and quantification were 5 and 25 µg/mL, respectively. The relative standard deviation (%) was below 15 % for the evaluation of precision and the mean recovery was 77 %. The extracting procedure followed HPLC analysis showed their applicability in order to examine 5- FU in surfaces samples. Moreover, it could be suggested that the developed method is an alternative in the monitoring of the occupational exposure to antineoplastic agents, once the analyte in question is considered an indicator for this purpose.Colegio de Farmacéuticos de la Provincia de Buenos Aire

A review of the multicriteria decision analysis applied to oil and gas decommissioning problems

Regardless of the economic activity, decommissioning decisions are often highly complex. This is due to the diversity of operational and local parameters, as well as the multitude of stakeholders involved, who generally have conflicting interests. This sets up a challenging multi-criteria decision problem on the activities to be carried out during the decommissioning process. This paper aims to present an overview of decision-support tools applied to decommissioning, and covers many economic sectors, with a focus on the oil and gas sector and on multi-criteria decision analysis (MCDA) methods. The paper delves deep into the aspects to be considered before reaching a decision, examining the experiences and methods found both in industrial reports and in academic papers