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In this paper, we bring forward an effective strategy, solvothermal postsynthesis, to prepare ordered mesoporous silica materials with highly branched channels. Structural characterizations indicate that the titled mesoporous materials basically have the cubic double gyroidal (space group Ia-3d) structure with small fraction of distortions. The mesopore sizes and surface areas can be up to 8.8 nm and 540 m2/g, respectively, when microwave digestion is employed to remove the organic templates. A phase transition model is proposed, and possible explanations for the successful phase transition are elucidated. The results show that the flexible inorganic framework, high content of organic matrix, and nonpenetration of poly(ethylene oxide) segments may facilitate the structural evolution. This new synthetic strategy can also be extended to the preparation of other double gyroidal silica-based mesoporous materials, such as metal and nonmetal ions doped silica and organo-functionalized silica materials. The prepared 3D mesoporous silica can be further utilized to fabricate various ordered crystalline gyroidal metal oxide "negatives". The mesorelief "negatives" (Co3O4 and In2O3 are detailed here) prepared by impregnation and thermolysis procedures exhibit undisplaced, displaced, and uncoupled enantiomeric gyroidal subframeworks. It has been found that the amount of metal oxide precursors (hydrated metal nitrates) greatly influence the (sub)framework structure and single crystallinity of the mesorelief metal oxide particles. The single crystalline gyroidal metal oxides are ordered both at mesoscale and atomic scale. However, these orders are not commensurate with each other.

The 1−2 nm SiQDs can photocatalyze CO2 reduction and dye (methyl red) degradation, while 3−4 nm SiQDs can photocatalyze selective oxidation of benzene to phenol, owing to tunable band gap and excellent photoconductive properties of SiQDs.

Si quantum dots, nanoparticles, nanowires, and ordered Si complex micro-/nanostructures can be obtained directly from silicon wafer by a polyoxometalate-assisted electrochemical method.

Mesoporous silica with Ia3̄d structure has been successfully prepared by using mixed surfactants of commercially available nonionic block copolymer P123 (EO20PO70EO20) and anionic sodium dodecyl sulfate (SDS) as structure-directing agents through an acid-catalyzed silica sol−gel process. XRD, TEM, and N2 sorption measurements show that the products have highly ordered bicontinuous cubic mesostructure with high surface area (∼770 m2/g), large pore volume (∼1.5 cm3/g), and uniform pore size (∼10 nm). Effects of preparation parameters on the formation of the mesostructure have been extensively investigated. It is found that the molar ratios of SDS/P123 between 2.1 and 2.5 and that of silicic species to P123 in the range from 40 to 75 are favorable for the formation of highly ordered Ia3̄d mesostructure. Prolonging hydrothermal treatment time leads to almost unchanged cell parameters of the products, whereas there is obvious increase of the pore sizes and pore volume. The results show that resultant template-free mesoporous silica products have excellent thermal stability, and they are more stable in N2 atmosphere than in air. Morphologies of the resultant materials can be further controlled by adding inorganic salt (such as Na2SO4) into the mixed surfactants system. Coral- and petaline-like mesoporous silica with continuous skeletons can be obtained. Understanding this synthesis system might be useful for economical and large-scale production of mesoporous materials with controllable structures.

Methylenetetrahydrofolate reductase (MTHFR) catalyzes the metabolism of folate and nucleotides needed for DNA synthesis and repair. Variations in MTHFR functions likely play roles in the etiology of lung cancer. The MTHFR gene has three nonsynonymous single nucleotide polymorphisms (i.e., C677T, A1298C, and G1793A) that have a minor allele frequency of >5%. We investigated the associations between the frequencies of MTHFR variant genotypes and risk of lung cancer in a hospital-based case-control study of 1,051 lung cancer patients and 1,141 cancer-free controls in a nonHispanic White population. We found that compared with the MTHFR 1298AA genotype, the 1298CC genotype was associated with a significantly increased risk of lung cancer in women [(odds ratio (OR), 2.09; 95% confidence interval (95% CI), 1.32-3.29)] but not in men (OR, 0.95; 95% CI, 0.62-1.45). The MTHFR 677TT genotype was associated with a significantly decreased risk of lung cancer in women (OR, 0.60; 95% CI, 0.40-0.92) but not in men. No association was found between the MTHFR G1793A polymorphism and risk of lung cancer. Further analysis suggested evidence of genedietary interactions between the MTHFR C677T polymorphism and dietary intake of vitamin B 6 , vitamin B 12 , and methionine in women and evidence of gene-environment interactions between the MTHFR C677T and A1298C polymorphisms and tobacco smoking in men. In conclusion, the polymorphisms of MTHFR may contribute to the risk of lung cancer in non-Hispanic Whites and modify the risk associated with the dietary and environmental exposure in a sex-specific manner. (Cancer Epidemiol Biomarkers Prev 2005;14(6):1477 -84)

Ce1−xBixO2−δand Au/Ce1−xBixO2−δexhibited superior catalytic performance towards 5-hydroxymethylfurfural conversion.

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