Enhanced Removal of Arsenic from Water by Synthetic Nanocrystalline Iowaite.

Nanocrystalline iowaite, a Mg/Fe-based layered double hydroxide (LDH) intercalated with chloride, was synthesized to evaluate its performance for arsenic removal from water and to investigate the contributing dearsenication mechanisms. It is characterized by fast arsenic sorption rates and has a much higher arsenic uptake capacity than other LDHs that are commonly used for water dearsenication. The surface adsorption of the solution arsenic onto the iowaite samples and the anion exchange of the arsenic in solution with chloride, which is originally in the iowaite interlayers, are the primary mechanisms for the uptake of arsenic by iowaite. In addition to the Coulombic attraction between arsenate/arsenite and positively charged layers of iowaite, the inner-sphere complexation of arsenic with Fe (instead of Mg) in the iowaite layers is responsible for the formation of more stable and stronger arsenic bonds, as indicated by both XPS and EXAFS analyses. Specifically, bidentate-binuclear and monodentate-mononuclear As-Fe complexes were detected in the arsenate removal experiments, whereas bidentate-mononuclear, bidentate-binuclear, and monodentate-mononuclear As-Fe complexes were present for the arsenite-treated iowaite samples. This study shows that nanocrystalline iowaite is a promising, low-cost material for arsenic removal from natural arsenic-rich waters or contaminated high-arsenic waters.

Effect of hyperoxia on the viability and proliferation of the primary type II alveolar epithelial cells.

To observe the effect of hyperoxia on the growth of type II alveolar epithelial cells (AEC II). The lungs of 19-day gestation fetal rats were primary cultured and the AEC II were purified by differential adhesion method. The cells were divided into control (normoxia) group and hyperoxia group. The cell growth, cell viability, cell apoptosis, and cell cycle were examined at 2, 4, 6, and 8 days of normoxia or hyperoxia exposure. The number of cells in hyperoxia-exposed group significantly decreased as compared to those of air control group. Number of cells in hyperoxia group was the highest at day 2 of exposure and gradually decreased with time. The viability of cells exposed to hyperoxia was substantially reduced compared with cells exposed to air. Percentage of cells in G1 phase and S phase in hyperoxia group increased gradually with increase in exposure duration and significant differences were seen at day 4 and day 6 compared with either the preceding time points and also with corresponding air-exposed cells. The percentage of both early apoptotic cells (Annexin-V(+)/PI(-)) and late apoptotic cells and necrotic cells (Annexin-V(+)/PI(+)) increased significantly in cells exposed to hyperoxia compared with cells exposed to air. Hyperoxia inhibits proliferation, viability and growth of AEC II and promotes apoptosis.

The effect of biweekly CHOP and standard CHOP in different subgroups of diffuse large B-cell lymphoma.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma. Conventional chemotherapy (CHOP: cyclophosphamide, doxorubicin, vincristine, prednisone) seems unsatisfactory, so modifications of CHOP are used to improve the efficacy. DLBCL is a highly variable tumor, with different responses to therapy. The aim of this study is to explore the association between immunophenotype and treatment response. PATIENTS AND METHODS: We analyzed the expression of Bcl-6, CD10, and MUM1 in 130 cases of DLBCL using immunohistochemistry. The cases were subdivided into germinal center B-cell-like (GCB) and non-GCB subtypes, and were randomly assigned to receive either 6-8 cycles of CHOP every 2 weeks or standard CHOP every 3 weeks. RESULTS: After a median followup duration of 40 months, 3-year overall survival of biweekly CHOP was better than standard CHOP in the non-GCB group (58.3 vs. 38.6%, p < 0.05). However, the therapeutic effect of biweekly CHOP and standard CHOP was not different in the GCB group (64.8 vs. 57.5%, p > 0.05). CONCLUSIONS: Immunohistochemistry analysis of different subgroups is useful to find the suitable therapy. Biweekly CHOP showed higher efficacy than standard treatment in the non-GCB subgroup.