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We investigated the anisotropic electrical transport and magnetic properties of FeSe0.5Te0.5 single crystals grown by the self-flux method. The in-plane resistivity shows a metallic-like temperature dependence, while the out-of-plane resistivity shows a broad hump with a maximum at around 64 K. The magnetization loops for H // c -axis and H // ab -plane are also different, for example, there is a typical second peak for H // c -axis. The in-plane critical current density is larger than the out-of-plane one. The coherence length and penetration depth were estimated by the Ginzburgâ€"Landau theory. The anisotropic parameter Îł depends on the applied magnetic field and the temperature. The coupling of superconducting FeSe(Te) layers and the flux pinning mechanism relevant to anisotropy are also discussed. [ABSTRACT FROM AUTHOR]

Objective: To investigate the cleavage of telomerase RNA component (hTR) by two DNAzymes and their effects on the expression of two apoptosis-related genes in a human mammary cancer cell line (MCF-7)., Methods: Two "10-23" DNAzymes (DzT and DzTi) targeted against hTR RNA and their analogues (DzT' and DzTi') were synthesized and used to cleave hTR RNA in vitro and in MCF-7 cells. Reverse transcriptional (RT) PCR amplification of a hTR DNA fragment and telomerase activity assay by PCR-enzyme-linked immunosorbent assay (ELISA) were performed to assess the cleavage efficiency. The biological effect of the DNAzymes was evaluated by measuring the expression of two apoptosis-related genes (bax-2 and bax)., Results: The unmodified DNAzyme, DzT, and its modified form, DzTi, which had an 3'-inverted thymidine added, could effectively cleave hTR mRNA in vitro. After transfection into MCF-7 cells, DzTi exhibited more powerful cleavage ability than DzT, and down-regulated the activity of telomerase (P<0.05). However, neither DzTi nor DzT displayed significant effect on the growth of the cells (P>0.05) and the expression of bax-2 and bax (P>0.05). DzT' and DzTi', derived from DzT and DzTi respectively with a base displacement in the conserved catalytic motif, did not exhibit notable cleavage effect on hTR RNA either in vitro or in the cells., Conclusions: The synthesized DNAzymes can effectively and specifically cleave hTR RNA and decrease the telomerase activity. As a newly found catalytic nucleic acid, DNAzymes will play an important role in gene therapy studies of tumors.

Aim: To investigate the characteristics of PPAR gamma ligands induced apoptosis in liver cancer cells., Methods: The effects of ligands for each of the PPAR gamma ligands on DNA synthesis and cell viability were examined in BEL-7402 liver cancer cells. Apoptosis was characterized by Hochest33258 staining, DNA fragmentation, TUNEL and ELISA, and cell cycle kinetics by FACS. Modulation of apoptosis related caspases expression by PPAR gamma ligands was examined by Western blot., Results: PPARgamma ligands, 15-deoxy-(12), (14)-prostaglandin J2 (15d-PGJ2) and troglitazone (TGZ), suppressed DNA synthesis of BEL-7402 cells. Both 15d-PGJ2 and TGZ induced BEL-7402 cell death in a dose dependent manner, which was associated with an increase in fragmented DNA and TUNEL-positive cells. At concentrations of 10 and 30 microM, 15d-PGJ(2) or troglitazone increased the proportion of cells with G(0)/G(1) phase DNA content and decreased those with S phase DNA content. There was no significant change in the proportion of cells with G(2)/M DNA content. The activities of Caspases-3, -6, -7 and -9 were increased by 15d-PGJ2 and TGZ treatment, while the activity of Caspase 8 had not significantly changed., Conclusion: The present results suggest the potential usefulness of PPAR gamma ligands for chemoprevention and treatment of liver cancers.

Aim: To investigate whether troglitazone (TGZ), the peroxisome proliferator-activated receptor (PPAR) gamma ligand, can induce apoptosis and inhibit cell proliferation in human liver cancer cell line HepG2 and to explore the molecular mechanisms., Methods: (3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), ((3)H) Thymidine incorporation, Hochest33258 staining, DNA ladder, enzyme-linked immunosorbent assay (ELISA), RT-PCR, Northern and Western blotting analyses were employed to investigate the effect of TGZ on HepG2 cells and related molecular mechanisms., Results: TGZ was found to inhibit the growth of HepG2 cells and to induce apoptosis. During the process, the expression of COX-2 mRNA and protein and Bcl-2 protein was down-regulated, while that of Bax and Bak proteins was up-regulated, and the activity of caspase-3 was elevated. Furthermore, the level of PGE(2) was decreased transiently after 12 h of treatment with 30 microM troglitazone., Conclusion: TGZ inhibits cell proliferation and induces apoptosis in HepG2 cells, which may be associated with the activation of caspase-3-like proteases, down-regulation of the expression of COX-2 mRNA and protein, Bcl-2 protein, the elevation of PGE2 levels, and up-regulation of the expressions of Bax and Bak proteins.