Rapid and Selective Uptake of Radioactive Cesium from Water by a Microporous Zeolitic-like Sulfide.

The fast and efficient removal of 137Cs+ ions from water is of great significance for the further treatment and disposal of highly active nuclear waste. Hitherto, although many layered metal sulfides have been proven to be very effective in capturing aqueous cesium, three-dimensional (3D) microporous examples have rarely been explored, especially compounds that are systematically used to study cesium ion exchange behaviors. In this paper, we present detailed Cs+ ion exchange properties of a 3D, microporous, zeolitic-like sulfide, namely K@GaSnS-1, in different conditions. Isotherm studies indicate that K@GaSnS-1 has a high cesium saturation capacity of 249.3 mg/g. In addition, it exhibits rapid sorption kinetics, with an equilibrium time of only 2 min. Further studies show that K@GaSnS-1 also displays a strong preference and good selectivity for cesium, with the highest distribution coefficient Kd value up to 3.53 × 104 mL/g. Also noteworthy is that the excellent cesium ion exchange properties are well-maintained despite acidic, basic, and competitive multiple-component environments. More importantly, the Cs+-exchanged products can be easily eluted and regenerated by a low-cost and eco-friendly method. These merits demonstrated by K@GaSnS-1 render it very promising in the effective and efficient separation of radioactive cesium from nuclear waste.

Pheophorbide a based photodynamic therapy induces apoptosis via mitochondrial-mediated pathway in human uterine carcinosarcoma.

Uterine carcinosarcoma is an aggressive neoplasm with low survival rates because of the lack of very effective chemotherapy protocol. Photodynamic therapy (PDT) is recently suggested to be an efficient protocol for this cancer. Pheophorbide a (Pa) is a chlorophyll degradation product in the green plant cells, its antitumor effect was reported on a number of human cancer cells with PDT approach. This study demonstrated that using Pa in PDT (Pa-PDT) significantly inhibited the human uterine sarcoma cell line MES-SA with an IC50 value of 0.5 µM at 24 h. Induction of apoptosis was found on the Pa-PDT treated cells according to the results of propidium iodide (PI) staining, annexin-V staining and DNA fragmentation assay. Pa was found to be localized in the mitochondria that lead to the depolarization of mitochondrial membrane potential by the rapid generation of singlet oxygen during light irradiation, where release of cytochrome c was detected and lead to the activation of intrinsic apoptotic pathway in MES-SA cells. Our findings revealed the therapeutic potential of Pa-PDT on the human uterine cancer.