113 research outputs found

    Lake drilling sciences for environmental change

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    The environmental changes in the area of Lake Baikal last 12 million years and marks of Lake Baikal research

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    名古屋大学Abstract - Deeper understanding of ecosystem is desired for better environmental protection and control. Historical events sometimes caused accidentally new structures of ecosystem. Natural laws behind the various phenomena may be clearer in the period of drastic change of climate or other environmental conditions. The lake drilling science seems well complementary for a breakthrough of ecology with its unique, continuous and general records. Here, a small discussion is made about the new possibility of the lake drilling science when it is conjugated with ecological science, phylogeny and evolution

    Suzaku Observation of the Anomalous X-ray Pulsar 1E 1841-045

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    We report the results of a Suzaku observation of the anomalous X-ray pulsar (AXP) 1E 1841-045 at a center of the supernova remnant Kes 73. We confirmed that the energy-dependent spectral models obtained by the previous separate observations were also satisfied over a wide energy range from 0.4 to ~70 keV, simultaneously. Here, the models below ~10 keV were a combination of blackbody (BB) and power-law (PL) functions or of two BBs wit h different temperatures at 0.6 - 7.0 keV (Morii et al. 2003), and that above ~20 keV was a PL function (Kuiper Hermsen Mendez 2004). The combination BB + PL + PL was found to best represent the phase-averaged spectrum. Phase-resolved spectroscopy indicated the existence of two emission regions, one with a thermal and the other with a non-thermal nature. The combination BB + BB + PL was also found to represent the phase-averaged spectrum well. However, we found that this model is physically unacceptable due to an excessively large area of the emission region of the blackbody. Nonetheless, we found that the temperatures and radii of the two blackbody components showed moderate correlations in the phase-resolved spectra. The fact that the same correlations have been observed between the phase-averaged spectra of various magnetars (Nakagawa et al. 2009) suggests that a self-similar function can approximate the intrinsic energy spectra of magnetars below ~10 keV.Comment: Accepted for publication in the PAS

    The Necessity of Career Education and Yamanashi Gakuin University’s Initiatives

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    Rare Earth Elements geochemistry of Lake Baikal sediment: its implication for geochemical response 5 to climate change during the Last Glacial/Interglacial transition,

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    Abstract Sediments deposited on the bottom of Lake Baikal have contributed to the understanding of a long-term environmental history of continents. Rare earth elements (REEs) along with major elements and loss on ignition (LOI) of Baikal sediments were determined with the aim of evaluating their suitability for a new paleoenvironmental proxy. Our interest is concentrated on paleoenvironmental change during the Last Glacial/Interglacial transition (LGIT). Chondrite-normalized REE patterns for Baikal sediments show a similar variation to those for typical upper continental crustal materials. Three parameters of (La/Yb) n (n: chondrite-normalized value) ratio, SREE/TiO 2 and Eu anomaly were used to express detailed characteristics of Baikal sediments. Depth profile of (La/Yb) n ratio shows abrupt change, whose timing corresponds to the beginning of climatic warming inferred from the profiles of SiO 2 /TiO 2 and LOI. In addition, (La/Yb) n ratio, SREE/TiO 2 and the degree of Eu anomaly correlate with each other. This suggests that inflow process of particulate materials into the lake may have changed during the LGIT. The analytical results of this study lead to the conclusion that REE is a useful paleoenvironmental proxy in the Baikal region.

    Primary cultures of human livers and their albumin-producing capacity.

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    Primary cultures of surgically obtained noncancerous portions of human liver tissues were made. Liver tissues were poorly dissociated with collagenase, but well dissociated with dispase. The yield and viability of cells were improved somewhat when dissociated with collagenase followed by dispase. The mean cell yield was 1.1 X 10(6) cells/g liver. The epithelial-like morphology of the dissociated liver cells was maintained for about one week, but thereafter degenerative alteration of cells was observed. In liver explant culture, an active outgrowth of cells was observed for more than one month. Albumin production in culture fluids from dissociated livers was detectable for about 2 weeks, but later became undetectable, while that from explant culture was detectable for at least one month. These data demonstrate that adult human hepatocytes can be isolated from noncancerous portions of livers with relatively high yield, and that albumin production of the dissociated cells is detectable for several days.</p

    Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer

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    The application of periodontal tissue in regenerative medicine has gained increasing interest since it has a high potential to induce hard-tissue regeneration, and is easy to handle and graft to other areas of the oral cavity or tissues. Additionally, bone morphogenetic protein-2 (BMP-2) has a high potential to induce the differentiation of mesenchymal stem cells into osteogenic cells. We previously developed a system for a gene transfer to the periodontal tissues in animal models. In this study, we aimed to reveal the potential and efficiency of periodontal tissue as a biomaterial for hard-tissue regeneration following a bmp-2 gene transfer. A non-viral expression vector carrying bmp-2 was injected into the palate of the periodontal tissues of Wistar rats, followed by electroporation. The periodontal tissues were analyzed through bone morphometric analyses, including mineral apposition rate (MAR) determination and collagen micro-arrangement, which is a bone quality parameter, before and after a gene transfer. The MAR was significantly higher 3–6 d after the gene transfer than that before the gene transfer. Collagen orientation was normally maintained even after the bmp-2 gene transfer, suggesting that the bmp-2 gene transfer has no adverse effects on bone quality. Our results suggest that periodontal tissue electroporated with bmp-2 could be a novel biomaterial candidate for hard-tissue regeneration therapy.Kawai M.Y., Ozasa R., Ishimoto T., et al. Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer. Materials, 15, 3, 993. https://doi.org/10.3390/ma15030993