A study of x-rays protection in a hip-joint radiography examination

幼小児を含めた若年者の股関節X線撮影検査においては鉛板などで生殖腺を防護して行うのが通常である。男性の場合は生殖腺は体外に露出しているので，それを鉛板で包むようにすればある程度目的は達成される。しかし，女性の場合，生殖腺は骨盤腔内に存在するため，卵巣及び子宮を防護でき診断目的領域にかからないように鉛板を成形し，腹壁上に置いて撮影する。X斬写真上ではグリッドで散乱線を除去しているため，鉛板の陰影がくっきりと撮影され，生殖腺は完全に防護されているように見える。しかし，体内では散乱線によるかなりの被曝があるものと考えられる。そこで今回，鉛板下の散乱線量を鉛板幅及び電圧を変化させ，ファントム内各深さの散乱線量を測定した。その結果，鉛板下の散乱線量が相当量認められ，その量は深さ3～4cmでピークを形成した。鉛板幅による変化は幅が狭いほど線量は大きくなり，電圧による変化は60kVと80kVを比べると80kVの方が多くなった。これを鉛板なしの場合と比較すると，ファントム内意さが増すにしたがい増大した。したがって，臨床において鉛板がずれて再撮影をすることのないよう細心の注意が必要であると考えられた。Usually in a hip-joint radiographic examination for the youth including children, the gonads should be well protected with an appropriate lead shield etc. Since the male gonads are in the outside of the body, if covered with a lead shield, the shield can protect them. However, in the case of the female, since the gonads of exist in a pelvic cavity, the lead shield is cut to a specific pattern so that it can protect the ovaries and the womb, and it is set on the abdomen during the radiographic exposure. Since the scattered radiation on an X-ray film can be removed with the grid, the image of a lead shield is obtained clearly, and the gonads seem to be protected completely. The shield can not protect the gonads of the female from the scattered radiation, though it protects them almost completely from the primary X-rays beam. Therefore, the gonads have radioactive contamination from scattered radiation. Then, in order to estimate the amount of scattered radiation under the lead shield, the dose under the shield was measured by using a phantom in this research, changing lead shield width, the tube-voltage, and the monitoring depth of a phantom. As a results, the dose under the lead shield was observed considerably and showed the peak at the depth of 3 or 4cm. Therefore, it was thought that a careful caution was required for obviating lead shield in clinical

ダイ44ジ ナンキョク チイキ カンソクタイ キショウ ブモン ホウコク 2003

この報告は,第44次南極地域観測隊気象部門が,2003年2月1日から2004年1月31日まで昭和基地において,及び2003年2月1日から2004年1月20日までドームふじ観測拠点において行った気象観測結果をまとめたものである.観測方法,測器,統計方法等は第43次隊とほぼ同様である. 越冬期間中,特記される気象現象として,次のものが挙げられる.1) 昭和基地での年平均気温は-9.0℃で観測史上第2位の高さであった.また,年合計雪日数は第1位の多さであった.2) 南極昭和基地上空におけるオゾン全量は,8月中旬にオゾンホールの目安である220 m atm-cm以下の値を観測した後,9月から10月にかけて過去最低レベルで推移した.6,9月は月平均値としては過去最も少なかった.2003年のオゾンホールは,欠損量(破壊量)が過去最大,面積が過去2位であり,例年よりも発達時期が早かった.3) ドームふじ観測拠点における越冬期間(2003年2月～2004年1月)の平均気温は-53.8℃,最低気温は7月23日に観測した-79.6℃であった.This report describes the results of meteorological observations at Syowa Station from February 1st, 2003 to January 31st, 2004, and at Dome Fuji Station from February 1st, 2003 to January 20th, 2004, carried out by the Meteorological Observation Team of the 44th Japanese Antarctic Research Expedition (JARE-44). The observation methods, instruments and statistical methods used by the JARE-44 were almost the same as those used by the JARE-43 observation team. Remarkable weather phenomena observed during the period of JARE-44 are as follows.1) Annual mean surface temperature in 2003 at Syowa Station was-9.0℃, which was the second highest value in the historical record of Syowa Station. The number of snow days in 2003 at Syowa Station was 233 days, which set a record at Syowa Station.2) The amount of total ozone over Syowa Station became lower than or equal to 220 m atm-cm in mid-August, and was close to the minimum levels from September to October. The monthly means of total ozone in June and September at Syowa Station were the lowest values since the beginning of monitoring. The ozone hole in 2003 appeared earlier than usual. The annual maximum in the ozone mass deficiency and the ozone hole area were the second largest and the largest, respectively.3) The mean surface temperature in the wintering period (Feb., 2003-Jan., 2004) at Dome Fuji Station was-53.8℃; the lowest temperature was-79.6℃ observed on July 23rd

DECIGO pathfinder

DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article

The status of DECIGO

DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) is the planned Japanese space gravitational wave antenna, aiming to detect gravitational waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz and 10 Hz and thus to open a new window for gravitational wave astronomy and for the universe. DECIGO will consists of three drag-free spacecraft arranged in an equilateral triangle with 1000 km arm lengths whose relative displacements are measured by a differential Fabry-Perot interferometer, and four units of triangular Fabry-Perot interferometers are arranged on heliocentric orbit around the sun. DECIGO is vary ambitious mission, we plan to launch DECIGO in era of 2030s after precursor satellite mission, B-DECIGO. B-DECIGO is essentially smaller version of DECIGO: B-DECIGO consists of three spacecraft arranged in an triangle with 100 km arm lengths orbiting 2000 km above the surface of the earth. It is hoped that the launch date will be late 2020s for the present

Meteorological observations at Syowa Station and at Dome Fuji Station in 2003 by the 44th Japanese Antarctic Research Expedition

This report describes the results of meteorological observations at Syowa Station from February 1st, 2003 to January 31st, 2004, and at Dome Fuji Station from February 1st, 2003 to January 20th, 2004, carried out by the Meteorological Observation Team of the 44th Japanese Antarctic Research Expedition (JARE-44). The observation methods, instruments and statistical methods used by the JARE-44 were almost the same as those used by the JARE-43 observation team. Remarkable weather phenomena observed during the period of JARE-44 are as follows.1) Annual mean surface temperature in 2003 at Syowa Station was-9.0℃, which was the second highest value in the historical record of Syowa Station. The number of snow days in 2003 at Syowa Station was 233 days, which set a record at Syowa Station.2) The amount of total ozone over Syowa Station became lower than or equal to 220 m atm-cm in mid-August, and was close to the minimum levels from September to October. The monthly means of total ozone in June and September at Syowa Station were the lowest values since the beginning of monitoring. The ozone hole in 2003 appeared earlier than usual. The annual maximum in the ozone mass deficiency and the ozone hole area were the second largest and the largest, respectively.3) The mean surface temperature in the wintering period (Feb., 2003-Jan., 2004) at Dome Fuji Station was-53.8℃; the lowest temperature was-79.6℃ observed on July 23rd

MMP24 as a Target of YAP Is a Potential Prognostic Factor in Cancer Patients

The extracellular matrix (ECM) surrounding cancer cells becomes stiffer during tumor progression, which influences cancer cell behaviors such as invasion and proliferation through modulation of gene expression as well as remodeling of the actin cytoskeleton. In this study, we show that MMP24 encoding matrix metalloproteinase (MMP)-24 is a novel target gene of Yes-associated protein (YAP), a transcription coactivator known as a mechanotransducer. We first examined the effect of substrate stiffness on MMP24 expression in MCF-7 human breast cancer cells and showed that the expression of MMP24 was significantly higher in cells grown on stiff substrates than that on soft substrates. The MMP24 expression was significantly reduced by knockdown of YAP. In contrast, the expression of constitutively active YAP increased MMP24 promoter activity. In addition, binding of YAP to the MMP24 promoter was confirmed by the chromatin immunoprecipitation (ChIP) assay. These results show that ECM stiffening promotes YAP activation, thereby inducing MMP24 expression. Based on the Human Protein Atlas database, breast cancer patients with lower MMP24 expression exhibit the worse survival rates overall. Thus, MMP24 may negatively regulate the aggressiveness of cancer cells under the stiff ECM environment during tumor progression

Loss of p53 function promotes DNA damage-induced formation of nuclear actin filaments

Abstract Tumor suppressor p53 plays a central role in response to DNA damage. DNA-damaging agents modulate nuclear actin dynamics, influencing cell behaviors; however, whether p53 affects the formation of nuclear actin filaments remains unclear. In this study, we found that p53 depletion promoted the formation of nuclear actin filaments in response to DNA-damaging agents, such as doxorubicin (DOXO) and etoposide (VP16). Even though the genetic probes used for the detection of nuclear actin filaments exerted a promotive effect on actin polymerization, the detected formation of nuclear actin filaments was highly dependent on both p53 depletion and DNA damage. Whilst active p53 is known to promote caspase-1 expression, the overexpression of caspase-1 reduced DNA damage-induced formation of nuclear actin filaments in p53-depleted cells. In contrast, co-treatment with DOXO and the pan-caspase inhibitor Q-VD-OPh or the caspase-1 inhibitor Z-YVAD-FMK induced the formation of nuclear actin filament formation even in cells bearing wild-type p53. These results suggest that the p53-caspase-1 axis suppresses DNA damage-induced formation of nuclear actin filaments. In addition, we found that the expression of nLifeact-GFP, the filamentous-actin-binding peptide Lifeact fused with the nuclear localization signal (NLS) and GFP, modulated the structure of nuclear actin filaments to be phalloidin-stainable in p53-depleted cells treated with the DNA-damaging agent, altering the chromatin structure and reducing the transcriptional activity. The level of phosphorylated H2AX (γH2AX), a marker of DNA damage, in these cells also reduced upon nLifeact-GFP expression, whilst details of the functional relationship between the formation of nLifeact-GFP-decorated nuclear actin filaments and DNA repair remained to be elucidated. Considering that the loss of p53 is associated with cancer progression, the results of this study raise a possibility that the artificial reinforcement of nuclear actin filaments by nLifeact-GFP may enhance the cytotoxic effect of DNA-damaging agents in aggressive cancer cells through a reduction in gene transcription