2,856 research outputs found

    Pressure effects on the superconducting thin film Ba1x_{1-x}Kx_{x}Fe2_{2}As2_{2}

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    We report electrical resistivity measurements on a high-quality Ba1x_{1-x}Kx_{x}Fe2_{2}As2_{2} thin film (x=0.4x=0.4) under pressure. The superconducting transition temperature (=39.95 K) of the optimally-doped thin film shows a dome shape with pressure, reaching a maximal value 40.8 K at 11.8 kbar. The unusually high superconducting transition temperature and its anomalous pressure dependence are ascribed to a lattice mismatch between the LaAlO3_3 substrate and the thin film. The local temperature exponent of the resistivity (n=dlnΔρ/dlnTn=d\text{ln}\Delta\rho/d\text{ln}T) shows a funnel shape around the optimal pressure, suggesting that fluctuations associated with the anomalous normal state are responsible for high-temperature superconductivity.Comment: To appear in Appl. Phys. Let

    An investigation of the role the donor moiety plays in modulating the efficiency of ‘donor-π-acceptor-π-acceptor’ organic DSSCs

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    Three ‘D-π-A-π-A’ based dyes have been synthesized featuring MeO-, MeS- and Me2N- as donor residues and benzothiadiazole and cyanoacrylic acid residues as acceptor units. UV–vis spectroscopy, solution electrochemistry and DFT modelling indicated that the Me2N- residue has the most significant effect on optical and redox properties of a photosensitizer. DSSCs with the Me2N- functionalized dye gave the highest power conversion efficiency of the series (η = 5.61%), presumably due to the better donor ability of this unit, which promotes more effective intramolecular charge transfer (ICT) characteristics

    Bioinformatics challenges in molecular epidemiology of cancers

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    Molecular epidemiology is the integration of molecular biologic techniques into epidemiologic study. With the advances in understanding of carcinogenesis and the human genome, there has been an evolution in the field of cancer epidemiology. However, traditional analyses of single genetic variants often fail to identify susceptibility genes for cancer risk. In particular, recent technological evolution has enabled high-throughput analyses for a number of genetic variants and driven accumulation of unprecedentedly large genome data, imposing bioinformatics challenges. These studies aim to integrate the genetic basis of complex diseases including cancers in which the interplay of multiple genetic and environmental risk factors may play an important role. Here we outline currently available approaches for detecting variants of cancer risk. We also review upcoming bioinformatics challenges and technical aspects in the field of molecular epidemiology, and discuss their future impact on the understanding of carcinogenesis and personalized strategies for cancer prevention and therapy
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