531 research outputs found

    Identification Of Ets1 As Ase Binding Protein: Unique Role In Age‐Related Gene Regulation

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106056/1/jth00156.pd

    Electron microscopy study of CeOx–Pd/α-Al2O3 catalysts for methane dry reforming

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    We have investigated the interaction between Pd and Ce in a 0.47 wt % CeOx–Pd 1 wt %/ -Al2O3 catalyst that is used in the reforming reaction of CH4 with CO2. The freshly reduced catalyst was characterized by various electron microscopy techniques, such as elemental mapping, Z-contrast imaging, and electron energy-loss spectroscopy to understand the role of Ce on a microscopic scale. The high spatial resolution elemental mapping indicates that CeOx is located in close proximity of the palladium nanoparticles. High-resolution lattice images and energy-loss spectra obtained in the vicinity of the Pd particles show an anisotropic distribution of CeOx crystallites limited to the interface region between Pd and the substrate but not covering the surface of the Pd nanoparticles. Energy-loss near edge fine structure of Pd M edges reveals that the Pd nanoparticles are not oxidized.Fil: Moreno, M. S.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Wang, Feiya. National Institute for Nanotechnology; CanadáFil: Malac, M.. National Institute for Nanotechnology; CanadáFil: Kasama, T.. University of Cambridge; Reino UnidoFil: Gigola, Carlos Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Costilla, Ignacio Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Sánchez, M. D.. Universidad Nacional del Sur. Departamento de Física; Argentin

    Measurement of the penetration depth and coherence length of MgB2 in all directions using transmission electron microscopy

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    We demonstrate that images of flux vortices in a superconductor taken with a transmission electron microscope can be used to measure the penetration depth and coherence length in all directions at the same temperature and magnetic field. This is particularly useful for MgB2_2, where these quantities vary with the applied magnetic field and values are difficult to obtain at low field or in the cc-direction. We obtained images of flux vortices from an MgB2_2 single crystal cut in the acac plane by focussed ion beam milling and tilted to 4545^\circ with respect to the electron beam about its aa axis. A new method was developed to simulate these images which accounted for vortices with a non-zero core in a thin, anisotropic superconductor and a simplex algorithm was used to make a quantitative comparison between the images and simulations to measure the penetration depths and coherence lengths. This gave penetration depths Λab=100±35\Lambda_{ab}=100\pm 35 nm and Λc=120±15\Lambda_c=120\pm 15 nm at 10.8 K in a field of 4.8 mT. The large error in Λab\Lambda_{ab} is a consequence of tilting the sample about aa and had it been tilted about cc, the errors would be reversed. Thus, obtaining the most precise values requires taking images of the flux lattice with the sample tilted in more than one direction. In a previous paper, we obtained a more precise value using a sample cut in the abab plane. Using this value gives Λab=107±8\Lambda_{ab}=107\pm 8 nm, Λc=120±15\Lambda_c=120\pm 15 nm, ξab=39±11\xi_{ab}=39\pm 11 nm and ξc=35±10\xi_c=35\pm 10 nm which agree well with measurements made using other techniques. The experiment required two days to conduct and does not require large-scale facilities. It was performed on a very small sample: 30×1530\times 15 microns and 200 nm thick so this method could prove useful for characterising new superconductors where only small single crystals are available.This work was funded by the Royal Society. Work at Eidgenossische Technische Hochschule, Zürich was supported by the Swiss National Science Foundation and the National Center of Competence in Research programme “Materials with Novel Electronic Properties.”This is the accepted manuscript for a paper published in Physical Review B, 91, 054505, 5 February 2015, DOI: 10.1103/PhysRevB.91.05450

    Direct measurement of the charge distribution along a biased carbon nanotube bundle using electron holography

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    Nanowires and nanotubes can be examined in the transmission electron microscope under an applied bias. Here we introduce a model-independent method, which allows the charge distribution along a nanowire or nanotube to be measured directly from the Laplacian of an electron holographic phase image. We present results from a biased bundle of carbon nanotubes, in which we show that the charge density increases linearly with distance from its base, reaching a value of similar to 0.8 electrons/nm near its tip. (C) 2011 American Institute of Physics. [doi:10.1063/1.3598468

    MTX and ETN Personal non-commercial use only

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    ABSTRACT. Objective. The aim of the Efficacy and Safety of Etanercept on Active Rheumatoid Arthritis Despite Methotrexate Therapy in Japan (JESMR) study is to compare the efficacy of continuation versus discontinuation of methotrexate (MTX) when starting etanercept (ETN) in patients with active rheumatoid arthritis (RA). Methods. In total, 151 patients with active RA who had been taking MTX were randomized to either ETN 25 mg twice a week with 6-8 mg/week MTX (the E+M group), or ETN alone (the E group). The primary endpoint at Week 52 was the radiographic progression assessed by van der Heijde-modified Sharp score. Results. The mean progression in total score at Week 52 was not significantly different, statistically, between the E+M group and the E group (0.8 vs 3.6, respectively; p = 0.06). However, a significant difference was observed in radiographic progression between Weeks 24 and 52 (0.3 vs 2.5; p = 0.03), and the mean progression of the erosion score was negative in the E+M group, which was significantly better than the E group at Week 52 (-0.2 vs 1.8; p = 0.02). Clinically, the cumulative probability plot of the American College of Rheumatology (ACR)-N values at Week 52 clearly demonstrated a superior response in the E+M group than in the E group. ACR20, 50, and 70 response rates at Week 52 in the E+M group (86.3%, 76.7%, and 50.7%) were significantly greater than those in the E group (63.8%; p = 0.003, 43.5%; p < 0.0001 and 29.0%; p = 0.01, respectively). Conclusion. MTX should be continued when starting ETN in patients with active RA

    Continuation of Methotrexate Resulted in Better Clinical and Radiographic Outcomes Than Discontinuation upon Starting Etanercept in Patients with Rheumatoid Arthritis: 52-week Results from the JESMR Study

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    ABSTRACT. Objective. The aim of the Efficacy and Safety of Etanercept on Active Rheumatoid Arthritis Despite Methotrexate Therapy in Japan (JESMR) study is to compare the efficacy of continuation versus discontinuation of methotrexate (MTX) when starting etanercept (ETN) in patients with active rheumatoid arthritis (RA). Methods. In total, 151 patients with active RA who had been taking MTX were randomized to either ETN 25 mg twice a week with 6-8 mg/week MTX (the E+M group), or ETN alone (the E group). The primary endpoint at Week 52 was the radiographic progression assessed by van der Heijde-modified Sharp score. Results. The mean progression in total score at Week 52 was not significantly different, statistically, between the E+M group and the E group (0.8 vs 3.6, respectively; p = 0.06). However, a significant difference was observed in radiographic progression between Weeks 24 and 52 (0.3 vs 2.5; p = 0.03), and the mean progression of the erosion score was negative in the E+M group, which was significantly better than the E group at Week 52 (-0.2 vs 1.8; p = 0.02). Clinically, the cumulative probability plot of the American College of Rheumatology (ACR)-N values at Week 52 clearly demonstrated a superior response in the E+M group than in the E group. ACR20, 50, and 70 response rates at Week 52 in the E+M group (86.3%, 76.7%, and 50.7%) were significantly greater than those in the E group (63.8%; p = 0.003, 43.5%; p < 0.0001 and 29.0%; p = 0.01, respectively). Conclusion. MTX should be continued when starting ETN in patients with active RA

    Creation of high mobility two-dimensional electron gases via strain induced polarization at an otherwise nonpolar complex oxide interface

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    The discovery of two-dimensional electron gases (2DEGs) in SrTiO3-based heterostructures provides new opportunities for nanoelectronics. Herein, we create a new type of oxide 2DEG by the epitaxial-strain-induced polarization at an otherwise nonpolar perovskite-type interface of CaZrO3/SrTiO3. Remarkably, this heterointerface is atomically sharp, and exhibits a high electron mobility exceeding 60,000 cm2V-1s-1 at low temperatures. The 2DEG carrier density exhibits a critical dependence on the film thickness, in good agreement with the polarization induced 2DEG scheme.Comment: 19 pages, 4 figs; Nano Letters,2015, published onlin

    Non-adiabatic spin torque investigated using thermally activated magnetic domain wall dynamics

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    Using transmission electron microscopy, we investigate the thermally activated motion of domain walls (DWs) between two positions in permalloy (Ni80Fe20) nanowires at room temperature. We show that this purely thermal motion is well described by an Arrhenius law, allowing for a description of the DW as a quasi-particle in a 1D potential landscape. By injecting small currents, the potential is modified, allowing for the determination of the non-adiabatic spin torque: the non-adiabatic coefficient is 0.010 +/- 0.004 for a transverse DW and 0.073 +/- 0.026 for a vortex DW. The larger value is attributed to the higher magnetization gradients present
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