216 research outputs found

    Layer-Resolved Ultrafast XUV Measurement of Hole Transport in a Ni-TiO2-Si Photoanode

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    Metal-oxide-semiconductor junctions are central to most electronic and optoelectronic devices. Here, the element-specificity of broadband extreme ultraviolet (XUV) ultrafast pulses is used to measure the charge transport and recombination kinetics in each layer of a Ni-TiO2-Si junction. After photoexcitation of silicon, holes are inferred to transport from Si to Ni ballistically in ~100 fs, resulting in spectral shifts in the Ni M2,3 XUV edge that are characteristic of holes and the absence of holes initially in TiO2. Meanwhile, the electrons are observed to remain on Si. After picoseconds, the transient hole population on Ni is observed to back-diffuse through the TiO2, shifting the Ti spectrum to higher oxidation state, followed by electron-hole recombination at the Si-TiO2 interface and in the Si bulk. Electrical properties, such as the hole diffusion constant in TiO2 and the initial hole mobility in Si, are fit from these transient spectra and match well with values reported previously

    Effect of Trailing-Edge Bevel Angle on the Sound Generation of a Flat Plate

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    Entangled light-matter interactions and spectroscopy

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    Entangled photons exhibit non-classical light–matter interactions that create new opportunities in materials and molecular science. Notably, in entangled two-photon absorption, the intensity-dependence scales linearly as if only one photon was present. The entangled two-photon absorption cross section approaches but does not match the one-photon absorption cross section. The entangled two-photon cross section also does not follow classical two-photon molecular design motifs. Questions such as these seed the rich but nascent field of entangled light–matter interactions. In this perspective, we use the experimental developments in entangled photon spectroscopy to outline the current status of the field. Now that the fundamental tools are outlined, it is time to start the exploration of how materials, molecules, and devices can control or utilize interactions with entangled photons

    Layer-resolved ultrafast extreme ultraviolet measurement of hole transport in a Ni-TiOâ‚‚-Si photoanode

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    Metal oxide semiconductor junctions are central to most electronic and optoelectronic devices, but ultrafast measurements of carrier transport have been limited to device-average measurements. Here, charge transport and recombination kinetics in each layer of a Ni-TiOâ‚‚-Si junction is measured using the element specificity of broadband extreme ultraviolet (XUV) ultrafast pulses. After silicon photoexcitation, holes are inferred to transport from Si to Ni ballistically in ~100 fs, resulting in characteristic spectral shifts in the XUV edges. Meanwhile, the electrons remain on Si. After picoseconds, the transient hole population on Ni is observed to back-diffuse through the TiOâ‚‚, shifting the Ti spectrum to a higher oxidation state, followed by electron-hole recombination at the Si-TiOâ‚‚ interface and in the Si bulk. Electrical properties, such as the hole diffusion constant in TiOâ‚‚ and the initial hole mobility in Si, are fit from these transient spectra and match well with values reported previously

    Familiáris myelodysplasiás szindróma és akut myeloid leukaemia klinikai és genetikai háttere

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    Myelodysplastic syndrome and acute myeloid leukaemia are mainly sporadic diseases, however, rare familial cases exist. These disorders are considered rare, but are likely to be more common than currently appreciated, and are characterized by the autosomal dominant mutations of hematopoietic transcription factors. These syndromes have typical phenotypic features and are associated with an increased risk for developing overt malignancy. Currently, four recognized syndromes could be separated: familial acute myeloid leukemia with mutated CEBPA, familial myelodysplastic syndrome/acute myeloid leukemia with mutated GATA2, familial platelet disorder with propensity to myeloid malignancy with RUNX1 mutations, and telomere biology disorders due to mutations of TERC or TERT. Furthermore, there are new, emerging syndromes associated with germline mutations in novel genes including ANKRD26, ETV6, SRP72 or DDX41. This review will discuss the current understanding of the genetic basis and clinical presentation of familial leukemia and myelodysplasia. Orv. Hetil., 2016, 157(8), 283-289

    A novel knockout mouse for the small EDRK-rich factor 2 (Serf2) showing developmental and other deficits

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    The small EDRK-rich factor 2 (SERF2) is a highly conserved protein that modifies amyloid fibre assembly in vitro and promotes protein misfolding. However, the role of SERF2 in regulating age-related proteotoxicity remains largely unexplored due to a lack of in vivo models. Here, we report the generation of Serf2 knockout mice using an ES cell targeting approach, with Serf2 knockout alleles being bred onto different defined genetic backgrounds. We highlight phenotyping data from heterozygous Serf2^{+/-} mice, including unexpected male-specific phenotypes in startle response and pre-pulse inhibition. We report embryonic lethality in Serf2^{-/-} null animals when bred onto a C57BL/6 N background. However, homozygous null animals were viable on a mixed genetic background and, remarkably, developed without obvious abnormalities. The Serf2 knockout mice provide a powerful tool to further investigate the role of SERF2 protein in previously unexplored pathophysiological pathways in the context of a whole organism
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