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Hydroxyapatite (HAP) was synthesized by sol– gel method. Different ratios of molybdenum oxide (1–15 % w/w) supported on HAP were prepared by the impregnation method and calcined at 400 C in a static air atmosphere. The catalysts were characterized by thermogravimetry, differential thermal analysis, X-ray diffraction, FTIR spectroscopy and nitrogen sorption measurements. The surface acidity of the catalysts was investigated by the dehydration of isopropyl alcohol and the adsorption of pyridine (PY) and 2,6-dimethyl pyridine (DMPY). The gas–phase oxidation of methanol to formaldehyde was carried out in a conventional fixed-bed flow type reactor using N2 as a carrier gas. The obtained results clearly revealed that HAP–MoO3 systems were active and selective towards the formation of formaldehyde. The maximum yield of formaldehyde (97 %) was achieved on the catalyst containing 5 wt% MoO3/HAP. The generation of Mo6?as Lewis together with Brønsted acid sites play the main role in the formation of formaldehyde.

Hydroxyapatite (HAP) was synthesized by sol– gel method. Different ratios of molybdenum oxide (1–15 % w/w) supported on HAP were prepared by the impregnation method and calcined at 400 C in a static air atmosphere. The catalysts were characterized by thermogravimetry, differential thermal analysis, X-ray diffraction, FTIR spectroscopy and nitrogen sorption measurements. The surface acidity of the catalysts was investigated by the dehydration of isopropyl alcohol and the adsorption of pyridine (PY) and 2,6-dimethyl pyridine (DMPY). The gas–phase oxidation of methanol to formaldehyde was carried out in a conventional fixed-bed flow type reactor using N2 as a carrier gas. The obtained results clearly revealed that HAP–MoO3 systems were active and selective towards the formation of formaldehyde. The maximum yield of formaldehyde (97 %) was achieved on the catalyst containing 5 wt% MoO3/HAP. The generation of Mo6?as Lewis together with Brønsted acid sites play the main role in the formation of formaldehyde.

The bulk Ge20Se50Te30 glasses were prepared by the melt-quenching method and the studied films of different thicknesses 100, 130, 160, and 200 nm were synthesized on glass substrates from the bulk glasses by the thermal evaporation technique under high vacuum. The stoichiometry of the studied thin films was determined by energy dispersive X-ray diffraction (EDX). The structure of the investigated bulk glasses as well as thin films was determined by X-ray diffraction (XRD). The XRD data confirmed the amorphous state of the bulk Ge20Se50Te30 glasses. However, the prepared films exhibit a mainly amorphous structure with some crystallites which are related to Se and GeSe2-phases. These crystalline particles were identified by scanning electron microscopy (SEM). The effect of thickness on the optical parameters of Ge20Se50Te30 films was investigated. The optical transmittance and reflectance spectra were recorded using a double beam spectrophotometer in the photon wavelength range of 190–900 nm. The values of some important optical constants such as the absorption coefficient, energy gap, refractive index, and extinction coefficient were calculated. The optical absorption measurements showed that the fundamental absorption edge is a function of film thickness. The indirect band-gap was found to decrease from 1.78 to 1.53 eV as the film thickness increased from 100 to 200 nm.

The bulk Ge20Se50Te30 glasses were prepared by the melt-quenching method and the studied films of different thicknesses 100, 130, 160, and 200 nm were synthesized on glass substrates from the bulk glasses by the thermal evaporation technique under high vacuum. The stoichiometry of the studied thin films was determined by energy dispersive X-ray diffraction (EDX). The structure of the investigated bulk glasses as well as thin films was determined by X-ray diffraction (XRD). The XRD data confirmed the amorphous state of the bulk Ge20Se50Te30 glasses. However, the prepared films exhibit a mainly amorphous structure with some crystallites which are related to Se and GeSe2-phases. These crystalline particles were identified by scanning electron microscopy (SEM). The effect of thickness on the optical parameters of Ge20Se50Te30 films was investigated. The optical transmittance and reflectance spectra were recorded using a double beam spectrophotometer in the photon wavelength range of 190–900 nm. The values of some important optical constants such as the absorption coefficient, energy gap, refractive index, and extinction coefficient were calculated. The optical absorption measurements showed that the fundamental absorption edge is a function of film thickness. The indirect band-gap was found to decrease from 1.78 to 1.53 eV as the film thickness increased from 100 to 200 nm.

The valuable effects of antioxidants supplemen- tation on lithium-induced nephrotoxicity has not been understood yet. The purpose of this study was to evaluate the renoprotective effect of zinc sulfate (Zn) and/or vitamin E (Vit. E) against lithium chloride (Li)-induced nephrotoxicity in rats. Forty male rats were divided into five groups. The first worked as controls and the other were treated with Li (20 mg/kg daily for 4 weeks). Group I of Li- treated was left without treatment, however, group II, III and IV were treated with Zn (10 mg/kg daily for 4 weeks), Vit. E (10 mg/kg, twice a week for 4 weeks), and the combination of Zn and Vit. E, respectively. Rats were killed for collection of blood and kidneys for biochemical and histological studies. The results showed a significant increase in Li in kidney tissue in all treated groups with Li, however, Zn was only increased in the groups treated with Zn, whereas Cu was similar in all treated and control groups. Plasma levels of creatinine, urea and glucose showed differences among the treated groups. The levels of lipid peroxidation, nitric oxide, glutathione, superoxide dismutase and catalase in renal tissue were significantly increased in Li-treated groups in comparison with the control and ameliorated by treatment with Zn and the combination of Zn and Vit. E. Histological observation showed perivascular edema and interstitial lymphocytic cell reaction in kidney of rats treated with Li, however co-treatment with Zn and/or Vit. E resulted in improvement of the histological changes. In conclu- sion Li-exposure causes a histological and biochemical changes mediated by oxidative stress and Li accumulation and co-treatment with Zn and/or Vit. E may protect against Li toxicity.

The valuable effects of antioxidants supplemen- tation on lithium-induced nephrotoxicity has not been understood yet. The purpose of this study was to evaluate the renoprotective effect of zinc sulfate (Zn) and/or vitamin E (Vit. E) against lithium chloride (Li)-induced nephrotoxicity in rats. Forty male rats were divided into five groups. The first worked as controls and the other were treated with Li (20 mg/kg daily for 4 weeks). Group I of Li- treated was left without treatment, however, group II, III and IV were treated with Zn (10 mg/kg daily for 4 weeks), Vit. E (10 mg/kg, twice a week for 4 weeks), and the combination of Zn and Vit. E, respectively. Rats were killed for collection of blood and kidneys for biochemical and histological studies. The results showed a significant increase in Li in kidney tissue in all treated groups with Li, however, Zn was only increased in the groups treated with Zn, whereas Cu was similar in all treated and control groups. Plasma levels of creatinine, urea and glucose showed differences among the treated groups. The levels of lipid peroxidation, nitric oxide, glutathione, superoxide dismutase and catalase in renal tissue were significantly increased in Li-treated groups in comparison with the control and ameliorated by treatment with Zn and the combination of Zn and Vit. E. Histological observation showed perivascular edema and interstitial lymphocytic cell reaction in kidney of rats treated with Li, however co-treatment with Zn and/or Vit. E resulted in improvement of the histological changes. In conclu- sion Li-exposure causes a histological and biochemical changes mediated by oxidative stress and Li accumulation and co-treatment with Zn and/or Vit. E may protect against Li toxicity.