2,607 research outputs found

    下大静脈及び腸骨静脈血栓を伴った後腹膜線維症の1例

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    53歳女.両下肢の腫脹と乏尿を主訴に当院受診, CT上両側水腎症と両側腸骨動脈を取り囲む辺縁不整な軟部組織陰影を認めた, 腎後性腎不全に対し両側ダブルJカテーテル留置, 造影CTにて下大静脈及び左腸骨静脈内に血栓を認め, また下大静脈造影及びMRアンジオグラフィー(MRA)にて左腸骨静脈閉塞を認めた.中心静脈血栓を伴う特発性後腹膜線維症と診断し, 経口よりプレドニゾロン及びワーファリン投与開始した.投与1ヵ月後のCT及びMRAで血栓の消失を認め, 水腎症は改善, 再発を認めていないA 53-year-old female was hospitalized for evaluation of swelling in the bilateral lower extremities. A computed tomography (CT) scan of the abdomen revealed bilateral hydronephrosis and features consistent with retroperitoneal fibrosis. Transfemoral venography and magnetic resonance angiography (MRA) showed thrombosis of both the left common iliac vein and inferior vena cava, and filling of numerous collateral veins in the retroperitoneal area. A diagnosis of idiopathic retroperitoneal fibrosis with central venous thrombosis was made. Ureteral stenting, medication with corticosteroids and subsequent warfarin were started, resulting in marked improvement of renal function and the lower extremities. Diagnosis and follow-up of deep venous thrombosis can be aided by MRA. Administration of steroids with anticoagulation was considered to be successful in the case presenting with deep venous thrombosis caused by retroperitoneal fibrosis

    Galvanomagnetic Tensors of Bismuth Single Crystals at Low Temperatures

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    A measurement of the galvanomagnetic tensors of bismuth at the liquid helium temperature and in the magnetic field up to 10 kilo Oersted is reported of three single crystals with different crystallographic orientations. All non-vanishing tensor components (except one) predicted by the crystal symmetry and Onsager\u27s reciprocal relation are measured. The dependency of the symmetric tensor components on the direction of the magnetic field is studied somewhat in detail. The experimental results are analysed semi-phenomenologically on the basis of the Boltzmann equation. Our experimental results of the absolute values and the field dependencies for the symmetric and antisymmetric tensor components respectively are such as expected theoretically in chemically pure samples. The anisotropy of the tensor components of typical type is, however, fairly small compared with that expected from the known energy surface anisotropy. This shows the importance of the anisotropic scattering or a failure of usual approximate theory, but unfortunately we could not obtain quantitative conclusion because a part of each anisotropy should have been attributed to undesirable boundary effect and other effects

    Magnetic Reconnection Triggered by the Parker Instability in the Galaxy: Two-Dimensional Numerical Magnetohydrodynamic Simulations and Application to the Origin of X-Ray Gas in the Galactic Halo

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    We propose the Galactic flare model for the origin of the X-ray gas in the Galactic halo. For this purpose, we examine the magnetic reconnection triggered by Parker instability (magnetic buoyancy instability), by performing the two-dimensional resistive numerical magnetohydrodynamic simulations. As a result of numerical simulations, the system evolves as following phases: Parker instability occurs in the Galactic disk. In the nonlinear phase of Parker instability, the magnetic loop inflates from the Galactic disk into the Galactic halo, and collides with the anti-parallel magnetic field, so that the current sheets are created in the Galactic halo. The tearing instability occurs, and creates the plasmoids (magnetic islands). Just after the plasmoid ejection, further current-sheet thinning occurs in the sheet, and the anomalous resistivity sets in. Petschek reconnection starts, and heats the gas quickly in the Galactic halo. It also creates the slow and fast shock regions in the Galactic halo. The magnetic field (B3μB\sim 3 \muG), for example, can heat the gas (n103n\sim 10^{-3} cm3^{-3}) to temperature of 106\sim 10^6 K via the reconnection in the Galactic halo. The gas is accelerated to Alfv\'en velocity (300\sim 300 km s1^{-1}). Such high velocity jets are the evidence of the Galactic flare model we present in this paper, if the Doppler shift of the bipolar jet is detected in the Galactic halo. Full size figures are available at http://www.kwasan.kyoto-u.ac.jp/~tanuma/study/ApJ2002/ApJ2002.htmlComment: 13 pages, 12 figures, uses emulateapj.sty, accepted by Ap

    Stacking Faults, Bound States, and Quantum Hall Plateaus in Crystalline Graphite

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    We analyze the electronic properties of a simple stacking defect in Bernal graphite. We show that a bound state forms, which disperses as |\bfk-\bfK|^3 in the vicinity of either of the two inequivalent zone corners \bfK. In the presence of a strong c-axis magnetic field, this bound state develops a Landau level structure which for low energies behaves as E\nd_n\propto |n B|^{3/2}. We show that buried stacking faults have observable consequences for surface spectroscopy, and we discuss the implications for the three-dimensional quantum Hall effect (3DQHE). We also analyze the Landau level structure and chiral surface states of rhombohedral graphite, and show that, when doped, it should exhibit multiple 3DQHE plateaus at modest fields.Comment: 19 page

    Transverse Galvanomagnetic Effect of Bismuth Single Crystal in a Strong Magnetic Field

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    Transverse galvanomagnetic effects of bismuth single crystal are measured in a strong magnetic field up to about 100 kilo Oersted at 4.2, 3.0 and 1.8K. And the twelve components of the galvanomagnetic tensor are obtained with respect to the magnetic field dependence. Furthermore the behaviors of the galvanomagnetic tensor components near the quantum limit of the magnetic quantization are studied, expecting that they can lend themselves to analyse the energy band structure. In a strong magnetic field, the amplitudes of the oscillatory part of the galvanomagnetic tensors are nearly temperature independent, and the behaviors of Hall effect appear to be different from the expected one from the classical theory of the two bands model
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