Mohamed Zaki

Corrosion behavior of AZ91E alloy was investigated in oxalate solution using potentiodynamic polarization and electrochemical impedance measurements (EIS). The effect of oxalate concentration was studied, where the corrosion rate increases with increasing oxalate concentration. The effect of added ions (Br-, Cl- or SiO ) on the electrochemical behavior of magnesium alloy in 0.1 M Na2C2O4 solution at 298 K, was investigated. It was found that the corrosion rate of 0.1 M oxalate solution containing silicate ion is lower than the blank (0.1 M Na2C2O4). This was confirmed by scanning electron microscope (SEM) observations. However, for the other added ions Br- or Cl-, the corrosion rate is higher than the blank. Keywords: AZ91E; Oxalate; EIS; Polarization; SEM.

Corrosion inhibition of mild steel in H3PO4 containing chloride or sulphate ions have been studied using different electrochemical techniques. The corrosion and hydrogen evolution of mild steel alloy in 2M H3PO4 acid containing 0.5M NaCl can be effectively inhibited by addition of natural product compound, Thymol (IPMP), of different concentrations. However, in 2M H3PO4 containing 0.5M Na2SO4 corrosion cannot be effectively inhibited. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements confirm the synergistic effects which describe the increase in the effectiveness of a corrosion inhibitor in the presence of Cl? ions in the corrosive medium. At any temperature, an increase in it leads to an increase of the corrosion rate and hydrogen evolution on mild steel. Polarization and EIS results are in good agreement with each other. The obtained results were confirmed by surface examination using scanning electron.

n/a

Eichhornia crassipes (Water hyacinth) is a hydrophyte which invaded all Egyptian water bodies causing serious problems of navigation and water quality deterioration. Known weight of the sample was successively extracted with hexane (E1), ethyl acetate (E2) and methanol ( E3). Antioxidant activity of extracts was performed by two complementary test system , 2.2'diphenyl-1- picryl hydrazyl (DPPH) and 2,2'- azino-bis (ethylbenzthiazoline-6- sulfonic acid (ABTS) methods which revealed the highest activity of E3 followed in descending order by E2 and E1. Fractionation of the promising methanol extract E3, produced five antioxidantly active fractions (a-e). Identification of the five fractions was performed using chromatographic and spectroscopic methods. Electrochemical impedance spectroscopy (EIS) experiments were carried out in artificial sea water (3.5% NaCl) to study the corrosion inhibition effect of Eichhornia crassipes (Water hyacinth) extracts (E1, E2, E3) and E3 fractions (a-e) on extruded AZ31E

Background$ Pneumonia is the most common cause of community-acquired infection requiring ICU admission'/+&U/ S/VHU/of patients with severe community acquired pneumonia; CAPD/admitted to the ICU develops respiratory failure and require mechanical ventilation ;MVD'/Objectives$ To assess the efficacy and safety of adjunctive low dose hydrocortisone infusion treatment in Egyptian ICU patients with CAP' Methods$ Hospitalized patientsK clinically and radiologically diagnosed with CAPK were randomized to receive hydrocortisone %)'W mg,h IV infusion for H/days or placeboK/along with antibiotics' The end-points of the study were improvement in PaO)$FIO) ;PaO)$FIO)/X/*&&/":/!%&& increase from study entryD and SOFA score by study day V and the development of delayed septic shock' Results$/V& patients were recruitedK/ (& of them received hydrocortisone and the remaining (& received placebo' By study day VK hydrocortisone treated patients showed a significant improvement in PaO)$FIO) and chest radiograph scoreK and a significant reduction in C-reactive protein ;CRPD levelsK Sepsis-related Organ Failure Assessment ;SOFAD/ scoreK and

The purpose of the present work was to investigate the effect of marine crustacean extract (MCE) from marine mantis shrimp Erugosquilla massavensis and silymarin on oxidative stress induced by carbon tetrachloride (CCl4) in rat liver and erythrocytes.
MATERIALS AND METHODS:
Male rats were randomly divided into 3 main groups, (1) control group which administered olive oil orally for 2 days, followed by distilled water for 7 consecutive days, (2) MCE group in which rats administered orally MCE, 250 mg/kg body weight for 9 consecutive days and (3) CCl4-treated group in which rats given CCl4 orally (2.5 ml/kg body weight) for 2 days. This group then subdivided into 5 subgroups. All subgroups treated orally for 7 consecutive days with distilled water (subgroup I), silymarin, 150 mg/kg body weight (subgroup II) and MCE at three tested doses 50, 100 and 250 mg/kg body weight (subgroups III, IV and V).
RESULTS:
The MCE and silymarin produced significant hepatoprotective effect by decreasing the activity of serum aminotransferases (ASAT and ALAT) and alkaline phosphatase (ALP) as well as malondialdehyde (MDA) level, and increasing the serum total protein, glutathione reduced (GSH) levels and the activities of glutathione-S-transferase (GST) and catalase (CAT). The MCE and silymarin also showed the same antioxidant effect on erythrocytes.
CONCLUSIONS:
The results of the present study, suggested that, the MCE could protect the liver and erythrocytes injuries perhaps, by its antioxidative effect, hence eliminating the deleterious effect of toxic metabolites from CCl4.