Properties of SnO2-based ceramics

Some SnO₂-based ceramics of the ternary and binary systems SnO₂-Sb₂O₃-CuO have been prepared and some of their properties have been measured. It was observed that most of their properties, which include density, porosity, d.c. electrical conductivity, as well as the crystal occurrence, were dependent on the presence of CuO. Crystal phase occurrence was investigated using the X-ray diffraction technique and it was found that the phases were predominantly SnO₂ and Sb₂O₄ crystals. The d.c. conductivity at different sintering temperatures was found to be enhanced by the simultaneous presence of Sb₂O₃ and CuO.     

Mechanisms of antioxidant action: Intermediates involved in the formation of sulphur acids from nickel dialkyl dithiophosphates

The oxidation of nickel dibutyl dithiophosphate by cumene hydroperoxide is shown to involve the formation of unstable sulphur acids which break down to give ionic catalysts for the decomposition of hydroperoxides.     

Some Properties of Methyl Diphenyl Phosphate

The physicochemical properties of methyl diphenyl phosphate (MDPP), alone or in binary and tertiary systems which include water, are presented. The data included are: melting point, boiling point, viscosity, surface tension, dipole moment, IR and UV spectra of MDPP, mutual solubilities of MDPP and water, viscosities, and solubilities of MDPP in several aqueous chlorides.     

Recent advances in nanostructured Sn−Ln mixed-metal oxides as sunlight-activated nanophotocatalyst for high-efficient removal of environmental pollutants

Environmental contaminants are toxic and undesirable compounds that can endanger the health and survivorship of human society. Thus, their removal from the environment has become a hot subject of research. Photocatalysis is accepted as a beneficial and environmentally friendly solution for the removal of undesirable contaminants. Its most substantial advantage is the capability to mineralize a wide variety of contaminants. Among various nanoscale compounds, mixed-metal oxides of tin (Sn) and lanthanide (Ln) with unique features and high reactivity have been demonstrated to be promising photocatalysts for removing undesirable contaminants. This review is aimed to give a comprehensive overview of current research progress concerning solar photocatalytic applications utilizing mixed-metal oxides of tin (Sn) and lanthanide (Ln). Diverse techniques for fabrication of mixed-metal oxides of tin (Sn) and lanthanide (Ln) and comprehensive experimental outcomes revealing their application in solar photocatalysis for removing undesirable pollutants are summarized. Besides, factors influencing the solar photocatalytic process have been briefly discussed. Ultimately, inspiring outlooks on this area of research are offered with the purpose of prevailing challenges.     

Diosmin Mitigates Cyclophosphamide Induced Premature Ovarian Insufficiency in Rat Model

The current study was designed to investigate the protective role of diosmin against cyclophosphamide-induced premature ovarian insufficiency (POI). Female Swiss albino rats received a single intraperitoneal dose of cyclophosphamide (200 mg/kg) followed by 8 mg/kg/day for the next 15 consecutive days either alone or in combination with oral diosmin at 50 or 100 mg/kg. Histopathological examination of ovarian tissues, hormonal assays for follicle stimulating hormone (FSH), estradiol (E2), and anti-Mullerian hormone (AMH), assessment of the oxidative stress status, as well as measurement of the relative expression of miRNA-145 and its target genes [vascular endothelial growth factor B (VEGF-B) and regulator of cell cycle (RGC32)] were performed. Diosmin treatment ameliorated the levels of E2, AMH, and oxidative stress markers. Additionally, both low and high diosmin doses significantly reduced the histopathological alterations and nearly preserved the normal ovarian reserve. MiRNA-145 expression was upregulated after treatment with diosmin high dose. miRNA-145 target genes were over-expressed after both low and high diosmin administration. Based on our findings, diosmin has a dose-dependent protective effect against cyclophosphamide-induced ovarian toxicity in rats.     

Surface and catalytic properties of Cr2O3/MgO system doped with manganese and cobalt oxides

The effects of cobalt and manganese oxides-doping on surface and catalytic properties of Cr₂O₃/MgO system have been investigated. The dopant concentration was changed between 1 and 5 mol% cobalt and manganese oxides. Pure and variously doped solids were subjected to heat treatment at 400 and 700 °C. The techniques employed were X-ray diffraction (XRD), nitrogen adsorption at –196 °C, catalytic conversion of iso-propanol at 200–400 °C using flow technique and catalytic decomposition of H₂O₂ at 20–40 °C. The results revealed that the doping process of the system investigated followed by calcinations at 400 or 700 °C, enhanced the solid–solid interactions between catalyst constituents yielding (-MgCrO₄, β-MgCrO₄) and MgCr₂O₄, respectively. Furthermore, manganese and cobalt oxide-doping for Cr₂O₃/MgO system increased its catalytic activity much towards H₂O₂-decomposition. The increase was, however, more pronounced in the case of manganese-doping. Opposite results have been observed in the case of iso-propanol conversion, which proceeds via dehydrogenation and dehydration reaction. The S_BET of the investigated system was found to decrease by increasing the dopant concentration. The doping process did not modify the activation energy of the catalyzed reaction, but rather changed the concentration of the catalytically active constituents without changing their energetic nature.     

Synthesis and Characterization of PVAc-b-PDMS-b-PVAc Triblock Copolymers by Atom Transfer Radical Polymerization Initiated by PDMS Macroinitiator

Poly(dimethylsiloxane) based triblock copolymer was synthesized from bis(bromoalkyl)-terminated PDMS macroinitiator (Br-PDMS-Br) and vinyl acetat telomers. Vinyl acetate telomers prepared from radical and controlled radical telomerization with Co(acac)₂/DMF catalyst and ligand, were used in atom transfer radical polymerization to synthesize Poly(vinylacetate-b-dimethylsiloxane-b-vinylcetate) triblock copolymer. The PDMS based triblock copolymers revealed a significant effect of Co(acac)₂/DMF on PVAc telomere which was used in the synthesis of highly ordered triblock copolymer on a well-defined microstructure. The results were confirmed by ¹H NMR and DSC indicating that a low T_g of PDMS in the microstructure of triblock copolymer has made the block copolymer flexible for new applications.