Phosphate uptake and phosphate transporter expression during immune cell proliferation in in vitro and ex vivo leukemic murine models

Dissertação de Mestrado, Ciências Biomédicas, Departamento de Medicina e Ciências Biomédicas, Universidade do Algarve, 2015

Anti-oxidative and anti-neuroinflammatory effects of ethyl acetate extract fractions of Suaeda asparagoides MIq

Purpose: To evaluate the in vitro antioxidant and anti-neuroinflammatory effects of Suaeda asparagoides ethylacetate extract (SAE) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Methods: The antioxidative activity of SAE was evaluated by measuring 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity spectrometrometrically. Cell viability was evaluated by 3-(4, 5dimethylthiazol-2-yl)-2, 5- diphenyl-tetrazolium bromide (MTT) assay, while LPS-stimulated BV-2 microglia were used to study the expression and production of inflammatory mediators, including nitric oxide (NO), inducible NO synthase (iNOS) and tumor necrosis alpha (TNF-α). Results: Pretreatment with SAE prior to LPS treatment significantly inhibited excessive production of NO (p < 0.001 at 20, 40, 80 and 100 μg/mL) in a dose-dependent manner, and was associated with down-regulation of expression of inducible nitric oxide synthase (iNOS). SAE also suppressed the LPSinduced increase in TNF-α level (p < 0.01at concentrations of 40 and 80 μg/mL) in BV-2 cells. Furthermore, DPPH-generated free radicals were inhibited by SAE in a concentration-dependent manner. Conclusion: These results indicate that SAE possesses strong anti-oxidant properties, and inhibits excessive production of pro-inflammatory mediators, including NO, iNOS and TNF-α, in LPS-stimulated BV-2 cells

Kinetic modeling for the synthesis of ethyl levulinate

This work is focused on studying the kinetics of esterification of levulinic acid in an isothermal batch reactor using ethanol as a reactant and as a protic polar solvent at the same time and in the presence of an acid catalyst (sulfuric acid). The choice of solvent is important as it affects the kinetics and thermodynamics of the reaction system moreover, the knowledge of the reaction kinetics plays an important role in the design of the process. This work is divided into two stages; The first stage is the experimental part in which the experimental matrix was developed by changing the process variables one at a time (temperature, molar ratio between reactants, and catalyst concentration) in order to study their influence on the kinetics; the second stage is using the obtained data from the experiments to build the modeling part in order to estimate the thermodynamics parameters.