152 research outputs found

    Development of high-pressure low-temperature plane strain testing apparatus for methane hydrate-bearing sand

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    AbstractA high-pressure low-temperature plane strain testing apparatus was developed for visualizing the deformation of methane hydrate-bearing sand due to methane hydrate production. Using this testing apparatus, plane strain compression tests were performed on pure Toyoura sand and methane hydrate-bearing sand with localized deformation measurements. From the results, it was observed that the methane hydrate-free specimens, despite their relatively high density, showed changes in compressive volume. Marked increases in the initial stiffness and strength of the methane hydrate-bearing sand were observed (methane hydrate saturation of SMH=60%). Moreover, the volumetric strain changed from compressive to dilative. For the specimens with methane hydrate, a dilative behavior above SMH=0% was observed. An image analysis showed that the shear bands of the methane hydrate-bearing sand were thinner and steeper than those of the host sand. In addition, the dilative volumetric strain in the shear band increased markedly when methane hydrate existed in the pore spaces

    On-line Response Tests on Case History of Earthquake Induced Deformation of River Dykes Founded on Saturated Sandy Deposits

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    River dykes and road embankments are frequently damaged during earthquakes. The liquefaction of foundation, the behavior of which is not yet well realized, is considered to be the main cause of the damage. Based on the results of past studies, the foundation of an embankment was divided into three zones to examine the failure modes. One-dimensional on-line earthquake tests, which were conducted by a combination of element tests and computer earthquake response analyses, were performed for such zones of actual river dykes damaged during earthquake. The cumulative horizontal displacement values obtained by the tests were compared with the measured embankment-crest settlement data, which showed that the liquefaction sliding failure under the toe of slope of such an embankment is found to be the most detrimental of all failure modes

    Infection of human CD4+ rabbit cells with HIV-1 the possibility of the rabbit as a model for HIV-1 infection

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    Although human T cell surface glycoprotein CD4 is the cellular receptor for human immunodeficiency virus 1 (HIV-1), the introduction of the human CD4 gene into murine cells does not render them susceptible to HIV-1 infection. Here we have established rabbit transfectant cell lines expressing human CD4 on the cell surface and demonstrated that the CD4+ rabbit transfectants could be readily infected by HIV-1 by co-cultivating with a HIV-1-infected human MOLT-4 T cell line (MOLT-4/HIV). Avid syncytia formation was observed upon co-cultivation and the syncytia abundantly produced HIV-1 mature particles, as revealed by electron microscopy. A significant increase of HIV-1 p24 antigen was also detected in the culture supernatant. The syncytia formation was blocked by pretreating the transfectant with anti-human CD4 or by pretreating the MOLT-4/HIV with anti-HIV-1 serum obtained from an infected individual, indicating that the syncytia formed as a result of the interaction of human CD4 on the rabbit transfectant with the HIV-1 envelope protein expressed on MOLT-4/HIV. In contrast, only a very small proportion of the rabbit transfectants expressed HIV-1-specific antigens upon infection with an HIV-1 stock. This may indicate that, although rabbit cells have partially acquired susceptibility to HIV-1 by transfection of human CD4 gene, rabbit cells may further require such a molecule as might be provided by MOLT-4 to become fully susceptible to HIV-1 infection. The possibility of the rabbit as a model for HIV-1 infection is also discusse

    An image sensor with fast extraction of objects\u27 positions - Rough vision processor

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    金沢大学大学院自然科学研究科情報システム金沢大学工学部An integration of the signal processing circuits with the image acquiring device, which is called the vision chip and can process information in parallel, is proposed for fast image processing. In applications for robot vision, not only the detailed information, such as shape or texture, but also the rough information, such as \u27something is around here\u27, are important and useful. We consider the detecting of centroids of objects in the focal plain as the rough vision processing, which is useful in practical application, and describe its implementation using two components; the centroid detector and the coordinate generator. First, we describe the fast flag generation algorithm indicating the centroid of objects, and its implementation using an analog parallel signal processing architecture. Next, we describe a novel encoding algorithm for flag positions indicating the centroids in order to obtain their coordinates

    Reactivity of the Serum from A-Bomb Survivors with the Tissues of Stomach, Liver and Kidney of Normal Rats

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    In order to evaluate delayed effects of radiation on pathological immune response an attempt was made to detect antibodies in the serum of atomic bomb survivors against kidney, liver, and parietal cells from rats. The following results were observed. Analysis of changes in antibody detection frequencies by age and exposure dose without considering sex showed that the rates for those exposed to 100 + rad showed a trend to increase with age for all three organs (P<0.01). However, in the 0 rad group, a significant trend to increase with age was noted for anti-kidney and antiliver antibodies only (P<0.01 for both). Analysis of changes in antibody detection frequencies by sex, age, and exposure dose showed that the detection frequencies increased significantly with age for all three organs in males exposed to 100 + rad (P < 0.05), but only the anti-liver antibody frequency increased significantly with age in males in the O rad exposure group. Females failed to shown any statistical changes in any exposure group

    シェーグレン症候群の新規自己抗原であるREG 蛋白の唾液導管細胞における発現誘導にはIL-6/STAT 経路が重要である

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    The regenerating gene, Reg, was originally isolated from a rat regenerating islet cDNA library, and its human homolog was named REG Iα. Recently, we reported that REG Iα mRNA as well as its product were overexpressed in ductal epithelial cells in the minor salivary glands of Sjögren׳s syndrome (SS) patients. This study was undertaken to elucidate the role of cytokines and the subsequent intracellular mechanism for induction of REG Iα in the salivary glands of SS patients. We prepared a reporter plasmid containing REG Iα promoter (−1190/+26) upstream of a luciferase reporter gene. The promoter plasmid was introduced by lipofection into human NS-SV-DC and rat A5 salivary ductal cells. The cells were treated with interleukin (IL)-6, IL-8, and a combination of the two. Thereafter transcriptional activity of REG Iα was measured by luciferase assay. We found that IL-6 stimulation, but not IL-8, significantly enhanced the REG Iα promoter activity in salivary ductal cells. Deletion analysis revealed that the region of −141 to −117 of the REG Iα gene was responsible for the promoter activation by IL-6, which contains a consensus sequence for signal transduction and activation of transcription (STAT). The introduction of siRNA for human STAT3 abolished IL-6-induced REG Iα transcription. These results showed that IL-6 stimulation induced REG Iα transcription through STAT3 activation and binding to the consensus sequence of REG Iα promoter in salivary ductal cells. This IL-6/STAT dependent REG Iα induction might play a role in the pathogenesis of SS.博士(医学)・甲第641号・平成27年11月27日Copyright © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CCBY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Interleukin-6/STAT pathway is responsible for the induction of gene expression of REG Iα, a new auto-antigen in Sjögren׳s syndrome patients, in salivary duct epithelial cells

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    The regenerating gene, Reg, was originally isolated from a rat regenerating islet cDNA library, and its human homolog was named REG Iα. Recently, we reported that REG Iα mRNA as well as its product were overexpressed in ductal epithelial cells in the minor salivary glands of Sjögren׳s syndrome (SS) patients. This study was undertaken to elucidate the role of cytokines and the subsequent intracellular mechanism for induction of REG Iα in the salivary glands of SS patients. We prepared a reporter plasmid containing REG Iα promoter (−1190/+26) upstream of a luciferase reporter gene. The promoter plasmid was introduced by lipofection into human NS-SV-DC and rat A5 salivary ductal cells. The cells were treated with interleukin (IL)-6, IL-8, and a combination of the two. Thereafter transcriptional activity of REG Iα was measured by luciferase assay. We found that IL-6 stimulation, but not IL-8, significantly enhanced the REG Iα promoter activity in salivary ductal cells. Deletion analysis revealed that the region of −141 to −117 of the REG Iα gene was responsible for the promoter activation by IL-6, which contains a consensus sequence for signal transduction and activation of transcription (STAT). The introduction of siRNA for human STAT3 abolished IL-6-induced REG Iα transcription. These results showed that IL-6 stimulation induced REG Iα transcription through STAT3 activation and binding to the consensus sequence of REG Iα promoter in salivary ductal cells. This IL-6/STAT dependent REG Iα induction might play a role in the pathogenesis of SS
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