105 research outputs found

    Equivalency of the quality of sublethal lesions after photons and high-linear energy transfer ion beams

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    The quality of the sublethal damage (SLD) after irradiation with high–linear energy transfer (LET) ion beams was investigated with low-LET photons. Chinese hamster V79 cells and human squamous carcinoma SAS cells were first exposed to a priming dose of different ion beams at different LETs at the Heavy Ion Medical Accelerator in the Chiba facility. The cells were kept at room temperature and then exposed to a secondary test dose of X-rays. Based on the repair kinetics study, the surviving fraction of cells quickly increased with the repair time, and reached a plateau in 2–3 h, even when cells had received priming monoenergetic high-LET beams or spread-out Bragg peak beams as well as X-ray irradiation. The shapes of the cell survival curves from the secondary test X-rays, after repair of the damage caused by the high-LET irradiation, were similar to those obtained from cells exposed to primary X-rays only. Complete SLD repairs were observed, even when the LET of the primary ion beams was very high. These results suggest that the SLD caused by high-LET irradiation was repaired well, and likewise, the damage caused by the X-rays. In cells where the ion beam had made a direct hit in the core region in an ion track, lethal damage to the domain was produced, resulting in cell death. On the other hand, in domains that had received a glancing hit in the low-LET penumbra region, the SLD produced was completely repaired

    ガク カンセツショウ カンジャ ニオケル MR ガゾウ ショケン ト リンショウ ショケン ノ ヒカク ケントウ

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    Two hundred eighteen (28.4%) of 768 patients with temporomandibular disorders (TMD), who visited the Clinic for Temporomandibular Disorders, Tokushima University Medical and Dental Hospital during the period of January 2006 through December 2007, were examined using magnetic resonance (MR) imaging. The present study assessed clinico-statistically the correlation between MR images and the clinical findings of 157 patients with complete registered data in our TMD reporting system. The following findings were obtained: 1. MR imaging showed anterior disk displacement in 125 joints (67.9%), rotational disk displacement in 45 joints (24.5%), and sideways disk displacement in 13 joints (7.1%). 2. Joint effusion (JE) was found in 42.7% of 157 patients; 48.0% in females and 23.5% in males. In addition, anterior or rotational disk displacement was observed in 97% of patients with JE. Furthermore, condyle bone change was significantly higher in joints with than without JE. 3. The appearance of JE was significantly higher on the symptomatic side than the asymptomatic side, but tenderness of the temporomandibular joint (TMJ) area or the value of the visual analog scale (VAS) regarding pain and problems in daily life was not related to the presence of JE

    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
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