There has been intense interest in understanding the self-assembled structure of conductive polymer nanowires due to the potential application in photovoltaics area. In the present study, free-standing poly(3-hexylthiophene) (P3HT) thin films consisting of H-aggregated and recently reported J-aggregated nanowires (NWs) were respectively prepared by the vacuum filtration method. The microstructure differences of both samples were studied in detail by combining the multiple techniques, i.e., synchrotron radiation WAXD, solid-state NMR, and IR spectroscopy. It is found that there is stronger π-π interaction ascribed to the slightly closer interchain stacking in J-aggregates than that in H-aggregates, although both aggregates take the same form I crystal modification. The subtle structural difference in the interchain stacking distance (Δd020 = 0.04 Å) is further manifested in the thermal behavior of both aggregates as indicated by the DSC curves, in which J-aggregates exhibit much higher melting point than that of H-aggregates (ΔT = 14 °C). Meanwhile, in situ synchrotron radiation WAXD study suggests that the low-temperature thermal transitions in both aggregates are associated with the shrinkage of the interchain distance. It is expected that this work will be helpful in understanding the structure-properties relationship of varying P3HT aggregate types.

Quarterthiophenes with long pendant alkyl side‐chains exhibit a unique, hitherto unreported polymorphism arising from side‐chain comformational changes. Those with long backbone structures show two different side‐chain conformationally induced polymorphs, one with a fully extended side‐chain and one with a bent side‐chain conformations. This unique polymorphism is a result of subtle differences in molecular architecture and can be induced by crystallization conditions.

CHP2 (calcineurin B homologous protein 2) was initially identified as a tumor-associated antigen highly expressed in hepatocellular carcinoma. Its biological function remains largely unknown except for a potential role in transmembrane Na ؉ /H ؉ exchange. In the present study, we observed that ectopic expression of CHP2 promoted the proliferation of HEK293 cells, whereas knockdown of endogenous CHP2 expression in HepG2 inhibited cell proliferation. When inoculated into nude mice, CHP2 transfected HEK293 cells displayed markedly increased oncogenic potential. In analysis of the underlying molecular mechanisms, we found that like calcineurin B, CHP2 was able to bind to and stimulate the phosphatase activity of calcineurin A. In accord with this, CHP2-transfected cells showed increased nuclear presence of NFATc3 (nuclear factor of activated T cells) and enhanced NFAT activity. Finally, both accelerated cell proliferation and NFAT activation following CHP2 transfection could be suppressed by the calcineurin inhibitor cyclosporine A, suggesting an intrinsic connection between these events. Taken together, our results highlighted a potential role of CHP2 in tumorigenesis and revealed a novel function of CHP2 as an activator of the calcineurin/NFAT signaling pathway.

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Two new dinuclear Ru(II) polypyridyl complexes containing three and ten methylene chains in their bridging linkers are synthesized and characterized. Their calf thymus DNA-binding and plasmid DNA photocleavage behaviors are comparatively studied with a previously reported, six-methylene-containing analog by absorption and luminescence spectroscopy, steady-state emission quenching by [Fe(CN)6](4-), DNA competitive binding with ethidium bromide, DNA viscosity measurements, DNA thermal denaturation, and agarose gel electrophoresis analyses. Theoretical calculations applying the density functional theory (DFT) method for the three complexes are also performed to understand experimentally observed DNA binding properties. The results show that the two complexes partially intercalate between the base pairs of DNA. Cellular uptake and colocalization studies have demonstrated that the complexes could enter HeLa cells efficiently and localize within lysosomes. The in-vitro antitumor activity against HeLa and MCF-7 tumor cells of the complexes are studied by MTT cytotoxic analysis. A new method, high-content analysis (HCA), is also used to assess cytotoxicity, apoptosis and cell cycle arrest of the three complexes. The results show that the lengths of the alkyl linkers could effectively tune their biological properties and that HCA is suitable for rapidly identifying cytotoxicity and can be substituted for MTT assays to evaluate the cell cytotoxicity of chemotherapeutic agents.