41 research outputs found

    The ASTRO-H X-ray Observatory

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    The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray

    Hitomi (ASTRO-H) X-ray Astronomy Satellite

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    The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E  >  2  keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month

    看護早期体験実習における学生の視点からみた学習経験

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    看護早期体験実習における教育活動の効果を評価するために,学生の視点からみた学習経験の特徴を明らかにした.看護大学1年次に在籍する23名のレポートを分析対象とし,質的帰納的研究技法によって抽出した181の学習経験の内容を分析した.結果,学生の学習経験は21のサブカテゴリーに分類され,意味内容の類似性によって, (1)生活者として素直な感情を抱き,患者の気持ちに同化する, (2)援助者としての自己意識が芽生える, (3)現実を知覚し援助者としての価値観を模索する, (4)生活者や援助者として,患者の思いを推察する, (5)学習者として,学習する価値や今後の自己の学習姿勢を発見する,の5つのカテゴリーに統合された. To evaluate the educational activities of early exposure to clinical practice, we clarified the characteristics of the learning experience from the viewpoints of influence factors upon students' recognition. Clinical practice reports by 23 students in the first year of nursing university were analyzed, and 181 experiences extracted by the qualitative inductive technique were analyzed. Results: the extracted experiences were classified into 21 sub-categories, which were further integrated according to the similarities of their meanings and contents into 5 core-categories: (1) having honest feelings as a living being and assimilating the patients' feelings, (2) developing self consciousness as a supporter, (3) perceiving reality and seeking value as a supporter, (4) contemplating patients' situations objectively, (5) understanding the patient's feeling as an ordinary citizen or a supporter

    Photoelectrochemical Etching Technology for Gallium Nitride Power and RF Devices

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    Photoelectrochemical (PEC) etching was used to fabricate deep trench structures in GaN-on-GaN epilayers grown on n-GaN substrates. The width of the side etching was less than 1 mu m, with high accuracy. The aspect ratio (depth/width) of a 3.3-mu m-wide trench with a PEC etching depth of 24.3 mu m was 7.3. These results demonstrate the excellent potential of PEC etching for fabricating deep trenches in vertical GaN devices. Furthermore, we simplified the PEC etching technology to permit its use in a wafer-scale process. We also demonstrated simple contactless PEC etching technologies for the manufacture of power and RF devices. A trench structure was fabricated in a GaN-on-GaN epilayer by simple contactless PEC etching. The role of the cathodic reaction in contactless PEC etching is discussed in relation to the application of a GaN HEMT epilayer on a semi-insulating substrate. Fortunately, the GaN HEMT structure contains an ohmic electrode that can act as a cathode in contactless PEC etching, thereby permitting the recess etching of a GaN HEMT epilayer grown on a semi-insulating SiC substrate. These results indicate that PEC etching technologies are becoming suitable for use in the fabrication of practical GaN power and RF devices

    The effect of breast density on the missed lesion rate in screening digital mammography determined using an adjustable-density breast phantom tailored to Japanese women.

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    ObjectiveDespite the high risk of missing lesions in mammography, the missed lesion rate is yet to be clinically established. Further, no breast phantoms with adjustable breast density currently exist. We developed a novel, adjustable-density breast phantom with a composition identical to that of actual breasts, and determined the quantitative relationship between breast density and the missed lesion rate in mammography.MethodsAn original breast phantom consisting of adipose- and fibroglandular-equivalent materials was developed, and a receiver operating characteristic (ROC) study was performed. Breast density, which is the fraction by weight of fibroglandular to total tissue, was adjusted to 25%, 50%, and 75% by arbitrarily mixing the two materials. Microcalcification, mass lesions, and spiculated lesions, each with unique characteristics, were inserted into the phantom. For the above-mentioned fibroglandular densities, 50 positive and 50 negative images for each lesion type were used as case samples for the ROC study. Five certified radiological technologists participated in lesion detection.ResultsThe mass-lesion detection rate, according to the area under the curve, decreased by 18.0% (p = 0.0001, 95% Confidence intervals [CI] = 0.1258 to 0.1822) and 37.8% (p = 0.0003, 95% CI = 0.2453 to 0.4031) for breast densities of 50% and 75%, respectively, compared to that for a 25% breast density. A similar tendency was observed with microcalcification; however, spiculated lesions did not follow this tendency.ConclusionsWe quantified the missed lesion rate in different densities of breast tissue using a novel breast phantom, which is imperative for advancing individualized screening mammography

    Diagnostic potential of miR-483 family for IGF-II producing non-islet cell tumor hypoglycemia

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    Objective: In insulin-like growth factor II (IGF-II) producing non-islet cell tumor hypoglycemia (NICTH), high molecular weight forms of IGF-II (big IGF-II) are produced as a cause of spontaneous hypoglycemia. MicroRNA (miRNA)-483 family, encoded in an intron lesion of IGF2 gene, is suggested to be co-expressed with IGF-II. Here, we tested whether serum miR-483-5p and -3p levels are associated with the presence of big IGF-II in NICTH. Design: Serum samples from patients who were suspected to have IGF-II producing NICTH (n = 42) were tested. MiR-483-5p and -3p levels were evaluated using quantitative PCR. IGF-II level was analyzed using ELISA. The presence of big IGF-II was identified by Western blotting. Results: Big IGF-II was detected in the sera of 32 patients. MiR-483-5p (P = 0.0015) and -3p (P = 0.027) levels were significantly higher in sera with big IGF-II (n = 32) than in those without (n = 10), whereas serum IGF-II level (P = 0.055) was not significantly different between the groups. The median serum concentration of miR-483-5p was ~10 times higher than that of miR-483-3p. Although a strong correlation was observed between the two miRNAs (r = 0.844, P < 0.0001), but neither of which was correlated with serum IGF-II level. The areas under the receiver operating characteristic curves of miR-483-5p (0.853) and -3p (0.722) were higher than that of IGF-II (0.694) for detecting the presence of big IGF-II. Conclusion: The associations of serum miR-483-5p and -3p levels with the presence of big IGF-II suggest the diagnostic potential of these miRNAs for IGF-II producing NICTH
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