16,734 research outputs found

    Formation and Stability of Cellular Carbon Foam Structures:An {\em Ab Initio} Study

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    We use ab initio density functional calculations to study the formation and structural as well as thermal stability of cellular foam-like carbon nanostructures. These systems with a mixed sp2/sp3sp^2/sp^3 bonding character may be viewed as bundles of carbon nanotubes fused to a rigid contiguous 3D honeycomb structure that can be compressed more easily by reducing the symmetry of the honeycombs. The foam may accommodate the same type of defects as graphene, and its surface may be be stabilized by terminating caps. We postulate that the foam may form under non-equilibrium conditions near grain boundaries of a carbon-saturated metal surface

    Perceived Factors Affecting the Integration-Responsiveness Framework: An Analysis from Chinese Multinationals Operating in Australia

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    This study extends quantitative and conceptual studies that have clarified and assessed the underlying factors influencing multinational corporations (MNCs) international business strategy choices relating to global integration and local responsiveness with the use of cross–level and in-depth interviews. Top management perceptions from nine Chinese MNCs (CMNCs) with operations in Australia are detailed and it is argued a contingency approach tends to prevail within firms with organisational, industrial, and environmental contingencies predominating

    High visibility two photon interference of frequency time entangled photons generated in a quasi phase matched AlGaAs waveguide

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    We demonstrate experimentally the frequency time entanglement of photon pairs produced in a CW pumped quasi phased matched AlGaAs superlattice waveguide. A visibility of 96.0+-0.7% without background subtraction has been achieved, which corresponds the violation of Bell inequality by 52 standard deviations

    Thermo-mechanical sensitivity calibration of nanotorsional magnetometers

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    We report on the fabrication of sensitive nanotorsional resonators, which can be utilized as magnetometers for investigating the magnetization dynamics in small magnetic elements. The thermo-mechanical noise is calibrated with the resonator displacement in order to determine the ultimate mechanical torque sensitivity of the magnetometer.Comment: 56th Annual Conference on Magnetism and Magnetic Material

    Early growth response gene 2 (Egr-2) controls the self-tolerance of T cells and prevents the development of lupuslike autoimmune disease

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    © 2008 Zhu et al. This article is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).Maintaining tolerance of T cells to self-antigens is essential to avoid autoimmune disease. How self-reactive T cells are kept functionally inactive is, however, unknown. In this study, we show that early growth response gene 2 (Egr-2), a zinc-finger transcription factor, is expressed in CD44(high) T cells and controls their proliferation and activation. In the absence of Egr-2, CD44(high), but not CD44(low) T cells, are hyperreactive and hyperproliferative in vivo. The accumulation of activated CD4(+)CD44(high) T cells leads to the development of a late onset lupuslike autoimmune disease characterized by the accumulation of interferon (IFN)-gamma and interleukin (IL)-17-producing CD4(+) T cells, loss of tolerance to nuclear antigens, massive infiltration of T cells into multiple organs and glomerulonephritis. We found that the expression of cyclin-dependent kinase inhibitor p21cip1 was impaired in Egr-2-deficient T cells, whereas the expression of IFN-gamma and IL-17 in response to T cell receptor ligation was significantly increased, suggesting that Egr-2 activates the expression of genes involved in the negative regulation of T cell proliferation and inflammation. These results demonstrate that Egr-2 is an intrinsic regulator of effector T cells and controls the expansion of self-reactive T cells and development of autoimmune disease.The Biotechnology and Biological Sciences Research Council, the Medical Research Council and the Wellcome Trust
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