Mohsen Mohammadi

Methoxy VO-salen complex: in vitro antioxidant activity, cytotoxicity evaluation and protective effect on CCl4-induced oxidative stress in rats.

Reactive oxygen species (ROS) play crucial roles in normal physiological processes. However, the overproduction of ROS is involved in the onset of many degenerative diseases. Regarding this fact, discovery of new antioxidants is interesting for many research groups. In this study, we evaluated the antioxidant properties of a methoxy VO-salen (MetVO-salen) complex employing various in vitro systems. In addition, the cytotoxic effect of MetVO-salen was assessed based on MTT in treated K562 cells. In an in vivo approach, the protective effect of MetVO-salen against CCl(4)-induced oxidative stress in rats was also investigated in terms of superoxide dismutase (SOD) and catalase (CAT) activities, as well as in terms of the levels of malondialdehyde (MDA) and glutathione (GSH). Our results indicated that MetVO-salen has an effective capability in scavenging superoxide (O*2-) and hydrogen peroxide (H(2)O(2)) radicals in a dose-dependent manner. In vivo results also showed that the administration of MetVO-salen to the CCl(4)-treated rats caused a significant (222%) increase in SOD activity, a 59% enhancement in GSH content and a 31% decrease in the level of MDA compared to the CCl(4)-treated control rats. Overall, MetVO-salen appears to be an effective antioxidant and is quite suitable for further biological evaluation.

Modulation of H2O2-induced mitogen-activated protein kinases activation and cell death in SK-N-MC cells by EUK134, a salen derivative.

Alzheimers disease is a neurodegenerative disorder that is characterized by the accumulation of senile plaques containing amyloid β (Aβ) and neurofibrillary tangles composed of hyperphosphorylated tau protein in the brain. Oxidative stress has been proposed to mediate Aβ-induced neurotoxicity. In that regard, we evaluated the ability of EUK134, a superoxide dismutase and catalase mimics, to protect human neuroblastoma cell line SK-N-MC against H(2)O(2) -induced oxidative stress. Our data clearly indicated that cell death induced by H(2)O(2) was reversed by EUK134. Likewise, lipid peroxidation, caspase-3 activation and intracellular reactive oxygen species formation all returned to control levels following pre-treatments with EUK134. Elevated phosphorylation of mitogen-activated protein kinases (MAPK) induced by H(2)O(2) in SK-N-MC cells was lowered by EUK134 in a dose-dependent manner. In addition, EUK134 decreased expression of pro-apoptotic genes p53 and Bax and enhanced expression of anti-apoptotic Bcl-2 gene. Taken together, these results suggest that EUK134 protects neuronal cells against H(2)O(2) toxicity by attenuating oxidative stress through inhibition of MAPK phosphorylation cascade.

A Coupled Wellbore/Reservoir Simulator to Model Temperature Distribution and Inflow Rate Profile in Wells With Multiple Pay Zones

abstract Interest in production logs is on the rise. The goal of this article is to point out one application of temperature logs; that is, inflow rate estimation. In this article a novel model is presented to simulate the temperature and pressure distribution in wells with multiple pay zones. This model accounts for nonhomogeneous multiphase flow with phase change, which has largely been ignored in the literature. The new model can be used as a tool to determine the inflow rate in each pay zone. The predicted inflow profile from our model was compared with spinner results. The error was between 10 and 15%, which is reasonable.

Inhibition effect of CO2 on asphaltene precipitation for an Iranian crude oil and comparison with N2 and CH4

The effects of N2, CH4 and CO2 injection on asphaltene precipitation have been experimentally investigated using a reservoir oil fluid from south of Iran, making use of light transmission method. The results are compared and the effects of injected gases on reducing asphaltene colloidal stability in oil are found in the following order: CH4> N2>CO2. It is observed that CO2 can act like an inhibitor and can increase the solubility of asphaltene, decreasing the asphaltene precipitation onset. A thermodynamic discussion explains the effect of CO2 on the solubility of asphaltene based on the solubility parameters of recombined oil and CO2, calculated from Peng-Robinson equation of state along with an empirical correlation for volumetric properties of CO2.