177 research outputs found

    Development of GMS data aquisition and database systems

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    It is well known that relativistic particles are hazardous to space equipments and astronauts, therefore it is important to monitor the space environment continuously. Since 1979 Hiraiso Solar Terrestrial Research Center has been watching the time sequence of high energetic particle flux everyday from the Space Environ- ment Monitor (SEM) onboard the Japanese Geostationary Meteorological Satellite. We developed a data acquisition system from the GMS-4 as well as its database system. The real time data plot, which is renewed every two minutes, has been presented by using http since 1994. We report the data acquisition system and the real time data display by means of the WWW browser along with the database system

    Real-time monitor of geomagnetic field in the near-pole regions as an index of magnetospheric electric field

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    Solar wind electric field that penetrates into the magnetosphere is an important key for causes of magnetosphenc disturbances. Since PC index, produced from the variation of the magnetic field in the near-pole regions is known to be a good indicator of magnetospheric electric field, monitoring the magnetic activity in the near-pole regions in real-time is useful for nowcasting/forecasting space weather. From the comparison of horizontal components of the magnetic field data between two stations, Eureka and Thule, it is found that the correlation between these two stations are quite high except for the summer months. This result suggests that magnetic field variations in the near-pole region are uniform, and the index can be produced throughout the year using magnetic field data in the northern and southern near-pole region

    Immunohistochemical Demonstration of Membrane-bound Prostaglandin E2 Synthase-1 in Papillary Thyroid Carcinoma

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    Microsomal prostaglandin E2 synthase-1 (mPGES-1) is an inducible enzyme that catalyzes the conversion of prostaglandin (PG) H2 to PGE2 in downstream of cyclooxygenase-2 (COX-2). Recent studies have obtained in vitro evidence that PGE2 participates in carcinogenesis, angiogenesis, and induction of matrix metalloproteinase-9 (MMP-9), which plays a crucial role in cancer invasion. However, implications for mPGES-1 in thyroid carcinomas remain to be determined. To address this issue, we performed an immunohistochemical analysis for mPGES-1, COX-2 and MMP-9 in 20 papillary thyroid carcinoma (PTC) patients. mPGES-1 immunoreactivity was localized in the cytoplasm of carcinoma cells in 19 cases, with an intensity that tended to be distinct at the interface between the tumor and the surrounding non-neoplastic tissue. Staining was more intense in regions with papillary arrangement, while it was less intense in regions with trabecular or solid arrangement. In many cases, immunohistochemical localization of COX-2 and MMP-9 resemble that of mPGES-1. Taken together, our results suggest the involvement of mPGES-1 in proliferation and differentiation of PTC as well as local invasion of PTC

    Low-level laser therapy for spinal cord injury in rats: effects of polarization

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    Abstract. The effects of laser polarization on the efficacy of near-infrared low-level laser therapy for spinal cord injury (SCI) are presented. Rat spinal cords were injured with a weight-drop device, and the lesion sites were directly irradiated with a linearly polarized 808-nm diode laser positioned either perpendicular or parallel to the spine immediately after the injury and daily for five consecutive days. Functional recovery was assessed daily by an open-field test. Regardless of the polarization direction, functional scores of SCI rats that were treated with the 808-nm laser irradiation were significantly higher than those of SCI alone group (Group 1) from day 5 after injury. The locomotive function of SCI rats irradiated parallel to the spinal column (Group 3) was significantly improved from day 10 after injury, compared to SCI rats treated with the linear polarization perpendicular to the spinal column (Group 2). There were no significant differences in ATP contents in the injured tissue among the three groups. We speculate that the higher efficacy with parallel irradiation is attributable to the deeper light penetration into tissue with anisotropic scattering

    LF radio observation of storm-time energetic electron precipitation observed in the auroral and sub-auroral regions

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    第3回極域科学シンポジウム/第36回極域宙空圏シンポジウム 11月26日(月)、27日(火) 国立極地研究所 2階ラウン

    Rb Regulates DNA Damage Response and Cellular Senescence through E2F-Dependent Suppression of N-Ras Isoprenylation

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    Oncogene-induced cellular senescence is well documented, but little is known about how infinite cell proliferation induced by loss of tumor suppressor genes is antagonized by cellular functions. Rb heterozygous mice generate Rb-deficient C cell adenomas that progress to adenocarcinomas following biallelic loss of N-ras. Here, we demonstrate that pRb inactivation induces aberrant expression of farnesyl diphosphate synthase, many prenyltransferases, and their upstream regulators sterol regulatory element-binding proteins (SREBPs) in an E2F-dependent manner, leading to enhanced isoprenylation and activation of N-Ras. Consequently, elevated N-Ras activity induces DNA damage response and p130-dependent cellular senescence in Rb-deficient cells. Furthermore, Rb heterozygous mice additionally lacking any of Ink4a, Arf, or Suv39h1 generated C cell adenocarcinomas, suggesting that cellular senescence antagonizes Rb-deficient carcinogenesis. © 2009 Elsevier Inc. All rights reserved
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