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ObjectiveTo examine perfluorooctanoic acid （PFOA）-induced DNA damage using a combined in vivo and in vitro experiment.MethodsAcellular nuclear DNA damage was used as a model to test the damage induced by exposure to 0.00， 0.13， 0.25， and 0.50 mmol/L PFOA for 1 h. The YAC-1 cell was used as the research model. In the cytotoxicity study， the effects of different dosages on cell activity were determined via CCK-8 assay. The final PFOA concentrations were 0， 1.0×10-8， 1.0×10-7， and 1.0×10-6 mol/L. DNA damage was detected after 3 d of exposure. Rats were gavage with 0， 10， 20， 40 mg/kg·BW PFOA twice. The liver， bone marrow， and peripheral blood of rats were removed 6 h after the last administration. Alkaline and neutral comet assay were performed to measure DNA damage. The micronucleus test was performed to measure bone marrow chromosome breakage.ResultsCompared with the control group， acellular and cell alkaline DNA comet assay result showed that the tail DNA% of acellular nuclear DNA increased significantly in each dose group （P0.05）. The tail DNA% of each dose group in the alkaline comet assay was significantly higher than that of the control group （P0.05）. Compared with the control group， the alkaline and neutral comet assay results showed that the tail DNA% of bone marrow， liver， and peripheral blood cells group showed no DNA breakage in each dose group （P>0.05）. Compared with the control group， the test of bone marrow micronucleus was negative （P>0.05）.ConclusionPFOA can cause DNA single-strand breakage at the subcellular level in vitro， and exposure does not induce DNA and chromosome breakage in rats after oral exposure.

CuO/TiO2 composites were prepared by the impregnation method, in which TiO2 nanosheets and nanorods are used as the precursors, respectively. We investigated the effect of the TiO2 surface structure on the activity and recyclability of the photocatalysts. The hydrogen production activities were tested in a 3 mol L−1 methanol aqueous solution under UV-light irradiation. After deposition of Pt, both Pt@CuO/TiO2 samples displayed higher hydrogen production activities than the Pt/TiO2 samples. The results reveal that the TiO2 sheet-based samples display higher hydrogen production activities and stability than the TiO2 rod-based ones. It is proposed that a more stable p-n heterojunction form at the interface between CuO and TiO2 nanosheets owing to the strong interaction of CuO with the {0 0 1} facets of the TiO2 sheets, which significantly refrains the recombination rate of electrons and holes. [ABSTRACT FROM AUTHOR]

Abstract: Highly crystalline orthorhombic Bi2MoO6 particles with high visible-light photocatalytic activity have been controllably synthesized via a facile hydrothermal process without adding any surfactant. The morphologies of Bi2MoO6 with nanosheet and microrod can be selectively obtained by adjusting the pH value of the reactant. The formation mechanisms of nanosheet and microrod structures were then discussed based on the H+ cations adsorption abilities on different crystal faces. The Bi2MoO6 samples prepared at acidic condition showed 12 times higher photocatalytic activity than that prepared at basic condition under visible-light irradiation. The reason for the big difference in the photocatalytic activities for the Bi2MoO6 samples obtained at different pH values were systematically studied based on their shape, size and the variation of local structure. [Copyright &y& Elsevier]