Bismuth tungstate has attracted great attention as a new photocatalyst working under visible irradiation. In this paper, we demonstrate a facile hydrothermal route for controllable synthesis of novel Bi(2)WO(6) hierarchical hollow spheres with an ultrahigh specific surface area in the presence of poly(vinyl pyrrolidone) at a proper C(2)H(5)OH/CH(3)COOH/H(2)O volume ratio. The obtained products are systematically studied by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller (BET) and UV-vis absorption spectroscopy. It is shown that the Bi(2)WO(6) hollow spheres are constructed of numerous nanoplates while the nanoplates consist of a great deal of nanoparticles. UV-vis spectrum is used to estimate the band gap energy (about 2.90 eV) of the Bi(2)WO(6) hollow spheres. The ultrahigh BET specific surface area of ca. 45.0 m(2) g(-1) is displayed for the Bi(2)WO(6) hierarchical hollow spheres, which is much higher than that for all the previously reported Bi(2)WO(6) products. The Bi(2)WO(6) hierarchical hollow spheres are displayed to possess superior photocatalytic activity in the photodegradation of rhodamine B (RhB) under visible light irradiation over other morphological products.

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The size and surface characteristics of a surrogate particle and Cryptosporidium parvum oocysts are important in determining the ability of the particle to mimic the behavior of C. parvum oocysts in filtration and particle transport experiments. The zeta potential, hydrophobicity, and filterability of a surrogate particle, 5 microm carboxylated latex microspheres, and oocysts were compared for a variety of solution conditions. C. pervum oocysts had a slightly negative zeta potential (-1.5 to -12.5 mV) at pH 6.7 over a wide range of calcium concentration (10(-6)-10(-1) M), while the fluorescent microspheres were more negatively charged under the same conditions (-7.4 to -50.2 mV). After exposure to 5 mg of C/L of Suwanee River natural organic matter (NOM), the ; potentials of both particles became significantly more negative, with the microspheres consistently maintaining a more negative zeta potential than the oocysts. Alum was able to neutralize the negative zeta potentials of both particles when in the presence of NOM, but nearly twice the dosage was required for the microspheres. NOM also affected the hydrophobicity of the particles by increasing the hydrophobicity of the relatively hydrophilic oocysts and decreasing the hydrophobicity of the relatively hydrophobic microspheres. A bench-scale filtration system removed less microspheres (40.3 +/- 1.5%) than oocysts (49.7 +/- 2.9%) when 0.01 M CaCl2 was supplied as coagulant. After preexposure to 5 mg of C/L of NOM, the removals of both particles declined significantly, and the removals of microspheres (13.7 +/- 1.5%) and oocysts (16.3 +/- 1.5%) were similar. Finally, the removal efficiencies of microspheres and oocysts in the presence of NOM increased to 69.3 +/- 3.5% and 67.7 +/- 6.4%, respectively, when alum was supplied as coagulant at the optimum dosage needed to destabilize the oocysts. These experimental results suggest that microspheres can be used to provide a conservative estimate of oocyst removal in filters containing hydrophilic negatively charged filter media.

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Catalyzed by Ru(bpy)3(BF4)2, the photoredox coupling of tertiary amines with acrylate derivatives including Baylis-Hillman adducts under visible light irradiation was successfully established. The scope of the substrates was broad, and thus an array of γ-aminobutyric ester derivatives was obtained in moderate to good yields.

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Flowerlike nanostructures of metals or compounds show interesting physical properties. In this article, novel flowerlike BaMoO4 nanostructures were successfully synthesized via a simple hydrothermal route. The as-synthesized products were studied by X-ray powder diffraction, scanning electron microscopy, Brunauer−Emmett−Teller, and transmission electron microscopy. The results showed that the nucleation and growth of the flowerlike nanostructures were governed by a nucleation−dissolution−recrystallization growth mechanism. The formation of the three-dimensional flowerlike BaMoO4 nanostructures was strongly dependent on the concentration of cetyltrimethylammonium bromide (CTAB). Control experiments were carried out to investigate various influencing factors on the morphology of the products. Different morphologies of BaMoO4 nanostructures were synthesized through adjusting CTAB concentration, temperature, and the volume ratio of N,N-dimethylacetamide to H2O. Luminescent properties of the flowerlike and multilayered BaMoO4 nanostructures consisting of nanosheets were studied, and the flowerlike BaMoO4 nanostructures showed a strong green emission, indicating that the flowerlike BaMoO4 nanostructures have great potential to be applied in luminescent areas.

Celastrus orbiculatus is used as a folk medicine in China for the treatment of numerous diseases. The ethyl acetate extract of Celastrus orbiculatus (COE) also displays a wide range of anti-cancer activities in the laboratory. However, the effectiveness of COE-induced autophagy and its mechanism of action in colorectal cancer cells have not been investigated thus far. The present study analyzed the effect of COE on HT-29 cell viability, apoptosis and autophagy using MTT assay, flow cytometry, transmission electron microscopy and western blotting. Additionally, the autophagy inhibitor 3-methyladenine and the autophagy inducer rapamycin were used to further explore the effects of COE-induced autophagy in HT-29 cells. The present study also examined whether the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR)/p70 ribosomal protein S6 kinase (p70S6K) signaling pathway was involved in the regulation of COE-induced autophagy. The results revealed that COE inhibited HT-29 cell proliferation and decreased cell survival in a time- and dose-dependent manner, and that COE possessed the ability to induce both apoptosis and autophagy in HT-29 cells. Furthermore, autophagy and apoptosis induced by COE synergized to inhibit colorectal cancer growth. In addition, COE treatment decreased the phosphorylation of Akt and its downstream effectors mTOR and p70S6K. Taken together, these results demonstrate that both autophagy and apoptosis were activated during COE treatment of HT-29 cells, and that COE-induced autophagy decreases the viability of HT-29 cells via a mechanism that may depend on the PI3K/Akt/mTOR/p70S6K signaling pathway. Furthermore, compounds that induce autophagy administered in combination with COE may be an attractive strategy for enhancing the anti-tumor potency of COE in colorectal cancer.