Dust in Supernovae and Supernova Remnants II: Processing and survival

Observations have recently shown that supernovae are efficient dust factories, as predicted for a long time by theoretical models. The rapid evolution of their stellar progenitors combined with their efficiency in precipitating refractory elements from the gas phase into dust grains make supernovae the major potential suppliers of dust in the early Universe, where more conventional sources like Asymptotic Giant Branch (AGB) stars did not have time to evolve. However, dust yields inferred from observations of young supernovae or derived from models do not reflect the net amount of supernova-condensed dust able to be expelled from the remnants and reach the interstellar medium. The cavity where the dust is formed and initially resides is crossed by the high velocity reverse shock which is generated by the pressure of the circumstellar material shocked by the expanding supernova blast wave. Depending on grain composition and initial size, processing by the reverse shock may lead to substantial dust erosion and even complete destruction. The goal of this review is to present the state of the art about processing and survival of dust inside supernova remnants, in terms of theoretical modelling and comparison to observations

Regulation of expression of thyroid hormone receptor isoforms and coactivators in liver and heart by thyroid hormone

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Thyroid hormone receptor-specific interactions with steroid receptor coactivator-1 in the pituitary

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Recent progress in large sized & high performance organic TFT array

Recently, we have developed 15.0 inch XGA organic TFT array and its LCD module, which might be world-largest array size and highest resolution in organic based device. This achievement is to be combined with several technical breakthroughs include new organic gate dielectric material, novel ohmic contact technique, and well-optimized process-architectures. Base on the newly developed organic gate dielectric with pentacene, we have obtained world-record field effect TFT mobilities in excess of 7cm2/Vsec and excellent on/off ratios as ∼106. For jumping up the OTFT research activities from laboratory scale to real production line, we have developed two key technologies. One is the new ohmic contact process with very common materials in the current LCD manufacturing such as ITO; the bottom contact structured OTFT with ITO source-drain electrode shows much the same performances as that with gold source-drain electrode. The other key technology to realize the large size organic device is that of optimizing the array structure to minimize the OTFT performance degradations. By combining these novel technologies, a 15.0" XGA prototype LCD panel is fabricated and shows good display performance.11scopu

Constitutive expression of mammalian nitric oxide synthase in tobacco plants triggers disease resistance to pathogens

Nitric oxide (NO) is known for its role in the activation of plant defense responses. To examine the involvement and mode of action of NO in plant defense responses, we introduced calmodulin-dependent mammalian neuronal nitric oxide synthase (nNOS), which controls the CaMV35S promoter, into wild-type and NahG tobacco plants. Constitutive expression of nNOS led to NO production and triggered spontaneous induction of leaf lesions. Transgenic plants accumulated high amounts of H2O2, with catalase activity lower than that in the wild type. nNOS transgenic plants contained high levels of salicylic acid (SA), and they induced an array of SA-, jasmonic acid (JA)-, and/or ethylene (ET)-related genes. Consequently, NahG co-expression blocked the induction of systemic acquired resistance (SAR)-associated genes in transgenic plants, implying SA is involved in NO-mediated induction of SAR genes. The transgenic plants exhibited enhanced resistance to a spectrum of pathogens, including bacteria, fungi, and viruses. Our results suggest a highly ranked regulatory role for NO in SA-, JA-, and/or ET-dependent pathways that lead to disease resistance.close131