No abstract

No abstract

No abstract

Background Magnesium oxide nanoparticles are characterized with a wide variety of applications and are mass-produced throughout the world. However, questions remain regarding their safety. There has been paucity of toxicology research on their side effects, especially under in vivo conditions. Objectives The present paper aims at evaluating the toxicity of administering 10–15 nm magnesium oxide nanoparticles to Wistar rat under in vivo conditions. In addition, hematology, biochemistry, and histopathology of the rats are examined at various concentrations (62.5-125-250-500 μg.mL -1 ) over 28-days period. Materials and Methods In this study, 35 male Wistar rats were randomly divided into five groups, comprising one control group and four experimental groups, assigned to various doses of MgO nanoparticles by intraperitoneal injection. Eventually, blood samples were collected, and all animals were sacrificed for liver and kidney tissue investigation. Results The findings showed that high concentrations of Magnesium oxide nanoparticles (250 and 500 μg.mL -1 ) significantly increased white blood cells, red blood cells, hemoglobin, and hematocrit compared with the control group (P < 0.05). Moreover, the nanoparticles elevated the levels of aspartate aminotransferase and alkaline phosphatase, whereas no significant difference in levels of alanine aminotransferase, gamma-glutamyl transpeptidase, urea, and creatinine were recorded in comparison with the control group (P < 0.05). Histopathological examinations in the rat’s liver showed proliferation of bile ductules, congestion in some regions of the liver sinusoids, and apoptotic cells (probably) in high-dose groups, but no histological changes were found in the kidney functions. Conclusions The results from the present study showed that the magnesium oxide nanoparticles in concentrations lower than 250 μg.mL -1 are safe for desired applications.

Vanadium polyoxometalate (PVMo) supported on mesoporous MCM-41, MCM-41-NH(2), as efficient and heterogeneous catalysts, with large surface area, for hydrocarbon oxidation with hydrogen peroxide is reported. Oxidation of the alkenes and alkanes gave product selectivities, which are similar to those observed for corresponding homogeneous catalyst. PVMo-MCM was prepared by introduction of PVMo into the mesoporous molecule sieves of MCM-41 by impregnation and adsorption techniques. The samples were characterized by X-ray diffraction (XRD), thermal gravimetric-differential thermal analysis (TG-DTA), FT-IR, scanning electron microscopy (SEM), UV-Vis and cyclic voltametry (CV). Ultrasonic irradiation has a particular effect on MCM-41 structural uniformity and reduced the reaction times and improved the product yields. In addition, the solid catalysts could be recovered and reused several times without loss of its activity.

No abstract

Polyoxometalates (POM) supported on zirconia, H(3)PW(12)O(40)/ZrO2, were prepared by incorporating polyphosphotungstate into a zirconia matrix via sol-gel technique that involving the hydrolysis of zirconium (IV) n-butoxide, Zr (n-OBu)(4), as the ZrO(2) source. This insoluble and readily separable catalyst was characterized by using XRD, FT-IR, SEM, and UV diffuse reflectance spectroscopy (UV-DRS), indicating that the polyphosphotungstate was chemically attached to the zirconia supports, and primary Keggin structure remained intact. The photocatalytic and sonocatalytic activity of the supported polyphosphotungstate was tested via degradation of different dyes in aqueous solutions. The POM-ZrO(2) nanocomposite showed higher photocatalytic and sonocatalytic activity than pure polyoxometalate or pure ZrO(2).

No abstract