168 research outputs found

    Die chinesisch-russischen Energiebeziehungen: Echte Freundschaft oder geheuchelte Partnerschaft?

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    Dieser Artikel beleuchtet die russisch-chinesische »strategische Partnerschaft« anhand der Beziehungen beider LĂ€nder im Energiebereich. Ostsibirien und der russische Ferne Osten verfĂŒgen ĂŒber noch unangetastete Öl- und Gasreserven, wĂ€hrend Chinas Energiebedarf immer weiter anwĂ€chst. Statt zu einer klaren Vereinbarung zwischen Lieferant und Verbraucher zu kommen, verliefen Diplomatie und Verhandlungen ĂŒber den Bau der Pipelines zwischen Moskau und Peking jedoch schwierig, was zum Großteil auf die russische Sorge zurĂŒckzufĂŒhren ist, das Wirtschaftswachstum Chinas zum eigenen geopolitischen Nachteil weiter anzukurbeln. Dementsprechend hat Russland den Bau von Pipelines nach China nur langsam vorangetrieben, stets begleitet vom GefĂŒhl betonten Misstrauens. Eine Ölpipeline wird Russland bald fertig stellen, die Gaspipeline wird jedoch in absehbarer Zukunft nur auf dem Papier existieren

    Simulation of I-V Hysteresis Branches in An Intrinsic Stack of Josephson Junctions in High TcT_c Superconductors

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    I-V characteristics of the high Tc_c superconductor Bi2_2Sr2_2Ca1_1C2_2O8_8 shows a strong hysteresis, producing many branches. The origin of hysteresis jumps is studied by use of the model of multi-layered Josephson junctions proposed by one of the authors (T. K.). The charging effect at superconducting layers produces a coupling between the next nearest neighbor phase-differences, which determines the structure of hysteresis branches. It will be shown that a solution of phase motions is understood as a combination of rotating and oscillating phase-differences, and that, at points of hysteresis jumps, there occurs a change in the number of rotating phase-differences. Effects of dissipation are analyzed. The dissipation in insulating layers works to damp the phase motion itself, while the dissipation in superconducting layers works to damp relative motions of phase-differences. Their effects to hysteresis jumps are discussed.Comment: 18 pages, Latex, 8 figures. To be appear in Phys.Rev.B Vol.60(1999

    Immunobiotic lactic acid bacteria beneficially regulate immune response triggered by poly(I:C) in porcine intestinal epithelial cells

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    This study analyzed the functional expression of TLR3 in various gastrointestinal tissues from adult swine and shows that TLR3 is expressed preferentially in intestinal epithelial cells (IEC), CD172a+CD11R1high and CD4+ cells from ileal Peyer's patches. We characterized the inflammatory immune response triggered by TLR3 activation in a clonal porcine intestinal epitheliocyte cell line (PIE cells) and in PIE-immune cell co-cultures, and demonstrated that these systems are valuable tools to study in vitro the immune response triggered by TLR3 on IEC and the interaction between IEC and immune cells. In addition, we selected an immunobiotic lactic acid bacteria strain, Lactobacillus casei MEP221106, able to beneficially regulate the anti-viral immune response triggered by poly(I:C) stimulation in PIE cells. Moreover, we deepened our understanding of the possible mechanisms of immunobiotic action by demonstrating that L. casei MEP221106 modulates the interaction between IEC and immune cells during the generation of a TLR3-mediated immune response

    Prevalence and Characteristics of TCFA and Degree of Coronary Artery Stenosis An OCT, IVUS, and Angiographic Study

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    AbstractBackgroundThe relationship between features of vulnerable plaque and angiographic coronary stenosis is unknown.ObjectivesThe purpose of this study was to systematically investigate the absolute number, relative prevalence, and characteristics of thin-cap fibroatheroma (TCFA) at different degrees of stenosis using optical coherence tomography (OCT), intravascular ultrasound, and coronary angiography.MethodsWe identified 643 plaques from 255 subjects who underwent OCT imaging in all 3 coronary arteries. They were divided into 3 groups on the basis of angiographic diameter stenosis: Group A (30% to 49%, n = 325), Group B (50% to 69%, n = 227), and Group C (>70%, n = 91).ResultsOCT showed that the absolute number of TCFA was greatest in Group A (n = 58), followed by Groups B (n = 40) and C (n = 33). However, the relative prevalence of TCFA was higher in Group C (36%) than in Groups A (18%) or B (18%) (p = 0.003 and p = 0.002, respectively). Fibrous cap of TCFA was thinner in Group C than in Groups A (p < 0.001) or B (p = 0.001). intravascular ultrasound showed that the plaque burden of TCFA was largest in Group C (80.1 ± 7.4%), compared with Groups B (67.5 ± 9.4%) and A (58.1 ± 8.4%). TCFA in Group C had a higher remodeling index than those in Group A (p = 0.002).ConclusionsThe absolute number of TCFA is 3 times greater in nonsevere stenosis than in severe stenosis. It is, however, twice as likely for a lesion to be TCFA in cases of severe stenosis than in nonsevere stenosis. Moreover, TCFA in severely-stenotic areas had more features of plaque vulnerability

    Formation of an Ultracarbonaceous Antarctic Micrometeorite through Minimum Aqueous Alteration in a Small Porous Icy Body

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    A comprehensive study of the organic chemistry and mineralogy of an ultracarbonaceous micrometeorite (UCAMM D05IB80) collected from near the Dome Fuji Station, Antarctica, was carried out to understand the genetic relationship among organic materials, silicates, and water. The micrometeorite is composed of a dense aggregate of ∌5 ”m-sized hollow ellipsoidal organic material containing submicrometer-sized phases such as glass with embedded metal and sulfides (GEMS) and mineral grains. There is a wide area of organic material (∌15 × 15 ÎŒm) in its interior. Low-Ca pyroxene is much more abundant than olivine and shows various Mg/(Mg + Fe) ratios ranging from ∌1.0 to 0.78, which is common to previous works on UCAMMs. By contrast, GEMS grains in this UCAMM have unusual chemical compositions. They are depleted in both Mg and S, which suggests that these elements were leached out from the GEMS grains during very weak aqueous alteration, without the formation of phyllosilicates. The organic materials have two textures—smooth and globular with an irregular outline—and these are composed of imine, nitrile and/or aromatic nitrogen heterocycles, and amide. The ratio of nitrogen to carbon (N/C) in the smooth region of the organics is ∌0.15, which is five times higher than that of insoluble organic macromolecules in types 1 and 2 carbonaceous chondritic meteorites. In addition, the UCAMM organic materials are soluble in epoxy and are thus hydrophilic; this polar nature indicates that they are very primitive. The surface of the material is coated with an inorganic layer, a few nanometers thick, that consists of C, O, Si, S, and Fe. Sulfur is also contained in the interior, implying the presence of organosulfur moieties. There are no isotopic anomalies of D, 13C, or 15N in the organic material. Interstellar photochemistry alone would not be sufficient to explain the N/C ratio of the UCAMM organics; therefore, we suggest that a very small amount of fluid on a comet must have been necessary for the formation of the UCAMM. The GEMS grains depleted in Mg and S in the UCAMM prove a very weak degree of aqueous alteration; weaker than that of carbonaceous chondrites. Short-duration weak alteration probably caused by planetesimal shock locally melted cometary ice grains and released water that dissolved the organics; the fluid would likely have not mobilized because of the very low thermal conductivity of the porous icy body. This event allowed the formation of the large organic puddle of the UCAMM, as well as organic matter sulfurization, formation of thin membrane-like layers of minerals, and deformation of organic nanoglobules.ă‚ąă‚Żă‚»ăƒ—ăƒˆćŸŒă«ă‚żă‚€ăƒˆăƒ«ăƒ»ă‚ąăƒ–ă‚čăƒˆăƒ©ă‚Żăƒˆç­‰ć€‰æ›Žă‚ă‚Šă€è‘—è€…æœ€ç”‚çšżăŻć€‰æ›Žć‰ăźă‚żă‚€ăƒˆăƒ«"Formation of an Ultracarbonaceous Antarctic Micrometeorite through Minimum Aqueous Alteration in a Small Porous Icy Body"This work was supported by a Grant-in-Aid for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology (No. 22224010, PI: H. Nagahara). The STXM facility at the beamline 5.3.2.2, ALS, is supported by the Department of Energy, Basic Energy Sciences Program
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