817 research outputs found

    BCAS: A Web-enabled and GIS-based Decision Support System for the Diagnosis and Treatment of Breast Cancer

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    For decades, geographical variations in cancer rates have been observed but the precise determinants of such geographic differences in breast cancer development are unclear. Various statistical models have been proposed. Applications of these models, however, require that the data be assembled from a variety of sources, converted into the statistical models’ parameters and delivered effectively to researchers and policy makers. A web-enabled and GIS-based system can be developed to provide the needed functionality. This article overviews the conceptual web-enabled and GIS-based system (BCAS), illustrates the system’s use in diagnosing and treating breast cancer and examines the potential benefits and implications for breast cancer research and practice

    Polyfluorene as a model system for space-charge-limited conduction

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    Ethyl-hexyl substituted polyfluorene (PF) with its high level of molecular disorder can be described very well by one-carrier space-charge-limited conduction for a discrete set of trap levels with energy \sim 0.5 eV above the valence band edge. Sweeping the bias above the trap-filling limit in the as-is polymer generates a new set of exponential traps, which is clearly seen in the density of states calculations. The trapped charges in the new set of traps have very long lifetimes and can be detrapped by photoexcitation. Thermal cycling the PF film to a crystalline phase prevents creation of additional traps at higher voltages.Comment: 13 pages, 4 figures. Physical Review B (accepted, 2007

    Pressure-induced Superconductivity in CaLi2

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    A search for superconductivity has been carried out on the hexagonal polymorph of Laves-phase CaLi2, a compound for which Feng, Ashcroft, and Hoffmann predict highly anomalous behavior under pressure. No superconductivity is observed above 1.10 K at ambient pressure. However, high-pressure ac susceptibility and electrical resistivity studies to 81 GPa reveal bulk superconductivity in CaLi2 at temperatures as high as 13 K. The normal-state resistivity shows a dramatic increase with pressure.Comment: bulk superconductivity in CaLi2 now confirme

    Demagnetization Borne Microscale Skyrmions

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    Magnetic systems are an exciting realm of study that is being explored on smaller and smaller scales. One extremely interesting magnetic state that has gained momentum in recent years is the skyrmionic state. It is characterized by a vortex where the edge magnetic moments point opposite to the core. Although skyrmions have many possible realizations, in practice, creating them in a lab is a difficult task to accomplish. In this work, new methods for skyrmion generation and customization are suggested. Skyrmionic behavior was numerically observed in minimally customized simulations of spheres, hemisphere, ellipsoids, and hemi-ellipsoids, for typ- ical Cobalt parameters, in a range from approximately 40 nm to 120 nm in diameter simply by applying a field

    Room temperature ageing of Al–Ni–RE (RE = La, Gd, Er) metallic glasses

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    The effect of long-term ageing of Al–TM–RE (TM = Ni, Ag, Cu; RE = rare earth) amorphous alloys under ambient conditions, and at a slightly elevated temperature (100 °C), has been studied. The phase evolution and devitrification kinetics were studied using differential scanning calorimetry, X-ray diffraction and transmission electron microscopy techniques. Partial crystallization was observed in Al89Ni6La5, Al87Ni6La7, Al87Ni5(Ag/Cu)1La7 alloys after several years under ambient conditions (20–50 °C), and in Al88Ni4La8, Al88Ni4Gd2Er6 and Al88Ni4Er8 alloys following a 90 h anneal at 100 °C