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三枝 純; 操上 広志; 安田 良; 栗原 和男; 新井 栄揮; 黒木 良太; 松橋 信平; 小澤 隆志; 後藤 浩明; 高野 隆夫; et al.
Health Physics, 104(3), p.243 - 250, 2013/03
被引用回数:3 パーセンタイル:25.48(Environmental Sciences)2011年3月の原子力発電所事故を受け、福島県内の多くの学校プールでは、放射性セシウムを含んだ水が農地に放出されることへの懸念から、プール水が排水できないままにあった。原子力機構では、プール水を除染するための方法として、各種のセシウム吸着材を使った方法や凝集沈殿法について調査・検討を行った。この結果をもとに、福島県内の学校プールにおいて除染の実証試験を行い、手法の見直しや改良を進めることにより、プール水の除染方法を構築した。
松橋 信平; 操上 広志; 安田 良; 高野 隆夫; 瀬古 典明; 長縄 弘親; 黒木 良太; 三枝 純
JAEA-Testing 2011-007, 189 Pages, 2012/07
東日本大震災を原因とする東京電力福島第一原子力発電所の事故で環境中に放出された放射性物質の降下により、福島県の学校のプール水中の放射性物質濃度が高くなり利用できなくなった。原子力機構では、プール水から放射性物質を取り除いてこれを安全に排水するために、プールでの実証試験を行った。一刻も早くプール水除染活動に貢献するため、その成果を取りまとめ、手引として公開した。本資料は、その後作成し、公開した英語版手引と合わせ、改めて試験研究の成果報告書として取りまとめたものである。
松橋 信平
放射線と産業, (132), p.42 - 48, 2012/06
福島第一原子力発電所事故への対策として、放射線利用研究の中核拠点である高崎研において進められている貢献として、環境中に拡散した放射性物質の回収・除去について、放射線グラフト重合捕集材をセシウム吸着材として用いるための研究開発や植物や微生物など生物の力を使って環境を修復する研究開発、高分子材料等に対する放射線照射の影響評価、水の放射線分解による水素発生機構の解明、福島積算線量マップ用データの自動集計プログラムの開発、及び放射線と安全に関する知識の普及、などの研究開発等の活動の実際を紹介する。
松橋 信平
原子力教科書; 放射線利用, p.210 - 238, 2011/02
ポジトロンイメージング技術は、放射性同位元素(Radioisotope: RI)のうち陽電子を放出して崩壊するポジトロン放出核種をトレーサとし、生体内を移行する化合物に標識されたRIに起源を持つ線を生体外から非侵襲で画像化計測する技術である。医学分野においては、PET(Positron Emission Tomography: ポジトロン断層診断)としてがんの画像診断などに利用され、がんの発見に威力を発揮している。この技術を、植物を対象とした研究に目的を特化して開発されたのが植物ポジトロンイメージング技術である。本稿では、この技術の開発の歴史と特徴,実際の植物研究への応用例について紹介する。
松橋 信平; 石岡 典子
原子力教科書; 放射線利用, p.240 - 273, 2011/02
放射線の医学分野における利用の概要を一般の読者にもわかりやすいような構成として、医療における放射線利用の歴史,我が国の医療における放射線利用の現状,放射線を利用した診断,放射線による治療,医療分野におけるその他の放射線利用,放射線利用の新たなチャレンジ、の各章に分け、それぞれについて概説した。また、さらに深い知識の獲得の手助けとなるよう、関連する文献や情報源についても紹介した。
石井 里美; 鈴井 伸郎; 伊藤 小百合; 石岡 典子; 河地 有木; 松橋 信平; 大竹 憲邦*; 大山 卓爾*; 藤巻 秀
JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 106, 2009/12
The nodule is a symbiotic organ of leguminous plants with rhizobium. Soybean plants utilize nitrogen (N) fixed by nodules from atmospheric N. Until now, N, a stable isotope, has long been used for studies of N fixation. However, because this method is invasive, it has been difficult to analyze an instant response to an environmental (ex. temperature, light) changes. The purpose of our study is to image the N fixation and analyze the kinetics quantitatively and noninvasively by using nitrogen gas labeled with N (half life: 10 min), a positron emitting isotope, and PETIS (positron-emitting tracer imaging system). Previously, we succeeded in producing N-labeled nitrogen gas However, it was required to purify the gas because it was likely to contain physiologically active N-labeled impurities. In this paper, we report development of a new method of production of pure N and the imaging of nitrogen fixation.
木名瀬 栄; 松橋 信平; 斎藤 公明
Nuclear Technology, 168(1), p.154 - 157, 2009/10
被引用回数:4 パーセンタイル:30.36(Nuclear Science & Technology)In the present study, self-AFs for photons and electrons in the spleen, kidneys, and liver of both a mouse and humans were evaluated using Monte Carlo simulations. For the mouse and human models, voxel phantoms based on computed tomography were used. The sources were assumed to be monoenergetic in the energy range 10 keV to 4 MeV and to be uniformly distributed in the spleen, kidneys, and liver. Interspecies scaling factors were determined using the results of the self-AFs for the voxel mouse and voxel human. Consequently, interspecies scaling factors were found to be dependent upon energy emitted in the source organ. It was found that the scaling factor for the photon self-AF, which is corrected by the cube root of the organ mass, shows a similar trend as a function of energy with the scaling factor for the electron self-AF.
渡邉 茂樹; 飯田 靖彦*; 鈴井 伸郎; 片渕 竜也*; 石井 里美; 河地 有木; 花岡 宏史*; 渡辺 智; 松橋 信平; 遠藤 啓吾*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 280(1), p.199 - 205, 2009/04
被引用回数:24 パーセンタイル:82.15(Chemistry, Analytical)Copper-64 was produced by the Ni(p,n)Cu reaction using enriched-NiO target. We investigated and compared the production yield of Cu for proton beams of various energies by using a thick target. Enriched-Ni was recovered with high yield by simple procedures. Imaging studies using positron emission tomography (PET) and positron emitting tracer imaging system (PETIS) were performed. We obtained clear images in PET and PETIS studies. The results of this study indicate that Cu can be utilized as a biomedical tracer for the molecular imaging both in animals and plants.
塚本 崇志*; 中西 啓仁*; 内田 博*; 渡辺 智; 松橋 信平; 森 敏*; 西澤 直子*
Plant & Cell Physiology, 50(1), p.48 - 57, 2009/01
被引用回数:88 パーセンタイル:90.07(Plant Sciences)The real-time translocation of iron (Fe) in barley ( L. cv. Ehimehadaka no.1) was visualized using the positron-emitting tracer Fe and a positron-emitting tracer imaging system (PETIS). PETIS allowed us to monitor Fe translocation in barley non-destructively under various conditions. In all cases, Fe first accumulated at the basal part of the shoot. Fe-deficient barley showed greater translocation of Fe from roots to shoots than did Fe-sufficient barley. In the dark, translocation of Fe to the youngest leaf was equivalent to or higher than that under the light condition, while the translocation of Fe to the older leaves was decreased, in both Fe-deficient and Fe-sufficient barley. This suggests the possibility that the mechanism and/or pathway of Fe translocation to the youngest leaf may be different from that to the older leaves. When phloem transport in the leaf was blocked by steam treatment, Fe translocation from the roots to older leaves was not affected, while Fe translocation to the youngest leaf was reduced. We propose a novel model in which root-absorbed Fe is translocated from the basal part of the shoots and/or roots to the youngest leaf via phloem in graminaceous plants.
鈴井 伸郎; 藤巻 秀; 石岡 典子; 河地 有木; 松橋 信平; 服部 浩之*; 茅野 充男*; 中村 進一*
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 112, 2008/11
Cadmium (Cd) is one of toxic heavy metal element. In order to decrease Cd accumulation in these products, it is necessary to elucidate mechanisms of Cd long-distance transport in the plant body. In this research, we tried to elucidate mechanisms of Cd long-distance transport by visualizing Cd transport in the plant body using positron emitting tracer imaging system (PETIS) and Cd. Oilseed rape plants (Brassica napus L.) were grown hydroponically for two weeks after sowing. In this PETIS experiment, different concentrations of Cd (0.1 M and 10 M) were added as a carrier to hydroponic solutions. 0.1 M is comparable to the Cd concentration in the soil solution from non Cd-polluted soils. 10 M is comparable to the toxic Cd concentration for oilseed rape plants. As a result, the pattern of Cd accumulation in the oilseed rape plants was similar in the different Cd concentrations (0.1 M and 10 M). These results indicate that in early stages, Cd concentration in the hydroponic solution do not have effects on Cd absorption in the root systems.
関本 均*; 河地 有木; 渡辺 智; 山口 良恵*; 小澤 豊明*; 志摩 大輔*; 石川 沙雪*; 藤巻 秀; 鈴井 伸郎; 石井 里美; et al.
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 108, 2008/11
The heavy metal hyperaccumulation phenotype seen in is the result of physiological differences at the cellular, organ and whole plant levels relative to non-hyperaccumulator plant species. These differences in Zn and Cd content relative to non-hyperaccumlators is due, in part, to enhanced metal transport at a number of different sites within the plant, including the root surface, xylem loading and reabsorption of xylem-born metals by leaf cells. In the present study, the taranslocation of Zn from root to the shoots in (hyperaccumulator) relative to (non-hyperaccumlator) was examined by the positron-emitting tracer imaging system (PETIS). The serial images of translocation of Zn from the roots to the shoots were acquired successfully, and the time activity curves for translocation of Zn in the basal shoot and the root region were analyzed in the two plants set in the same field of view. It was indicated that the translocation of Zn from the root to the shoot of , that is a Zn/Cd-hyperaccumulator, would be enhanced.
石井 里美; 鈴井 伸郎; 石岡 典子; 河地 有木; 松橋 信平; 大竹 憲邦*; 大山 卓爾*; 藤巻 秀
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 111, 2008/11
The nodule is a symbiotic organ of leguminous plants with rhizobium. Soybean plants utilize nitrogen (N) fixed by nodules from atmospheric N. Until now, N, a stable isotope, has long been used for kinetics of N fixation and dynamics of transport of fixed N. However, because this method is invasive, it has been difficult to analyze an instant response to an environmental (ex. temperature, light conditions) change with these methods because they are invasive. We are planning to image and analyze such kinetics and dynamics quantitatively and noninvasively by using nitrogen gas labeled with N (half life: 10 min), a positron emitting isotope, and PETIS (positron imaging tracer imaging system). In this paper, we report the synthesis and purification of N-labeled nitrogen gas (N).
飯田 靖彦*; 花岡 宏史*; Paudyal, P.*; Paudyal, B.*; 渡辺 智; 石岡 典子; 渡邉 茂樹; 松橋 信平; 吉岡 弘樹*; 樋口 徹也*; et al.
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 114, 2008/11
Optical imaging is recently developed for in vivo molecular imaging. It requires only a simple system, and has advantage of relatively low cost. Furthermore, optical imaging probes can provide the highest signal-to-noise ratio for molecular targeting, so optical imaging is ideal candidate for molecular imaging. In this study, we prepared a probe, which labeled with both radioisotope and fluorescent dye, and evaluated the difference of images from PET and optical imaging, and compare the characteristics of both imaging methods. From our results, multimodal imaging system can provide complementary information about the functional status of various tissues, and can improve the accuracy of tumor diagnosis.
諏訪 竜一*; 石井 里美; 鈴井 伸郎; 石岡 典子; 藤巻 秀; 松橋 信平; 藤田 耕之輔*; 河地 有木
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 109, 2008/11
Recently, Kawachi et al. (2006) established a method for the kinetic analysis of CO for studying photoassimilate transport in a leaf, using PETIS. The method quantitatively analyzes the photoassimilate transport under various light conditions. However, it is important to analyze photoassimilate transport under both dark and light conditions because leaves transport carbon under both these conditions (Mullen et al., 1988). In the present study, we developed a new method to analyze photoassimilate translocation, using PETIS, and CO. This novel method clarified the mechanism underlying photoassimilate translocation from a leaf under the dark condition by noninvasive, repeated imaging experiments, using the same specimen.
菊地 郁*; 石井 里美; 藤巻 秀; 鈴井 伸郎; 松橋 信平; 本多 一郎*; 河地 有木
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 110, 2008/11
To clarify the mechanism of the growth and development of fruits such as eggplant and tomato in relation to plant growth and yield, examination of the import of dry matter into fruits from other organs such as leaves is essential. Positron-emitting tracer imaging system (PETIS) noninvasively visualizes movement of C-labeled photoassimilate in plants. So we fed CO to a leaf and monitored the translocation of C-labeled photoassimilate into the eggplant fruit by PETIS.
河地 有木; 藤巻 秀; 鈴井 伸郎; 石井 里美; 渡邉 茂樹; 渡辺 智; 石岡 典子; 松橋 信平
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 107, 2008/11
The PETIS and its quantitative tracer images have the potential to analyze the plant physiology of a test plant. In order to acquire the analyzable dynamic data of PETIS images quantitatively, a scheduled work for constant quality controls are absolutely essential. The system uniformity and sensitivity on the plane of field of view (FOV) were measured using a flat uniform phantom. As a result of the activity dependence, we made a modification to the PETIS software in the sensitivity correction, and we recommend the following algorism; in some measurements for the plant study having very low-activity tracer, it may be preferable to correct sensitivity with low-activity phantom data. At the same time, the quantitative performance of PETIS is checked with time activity curves of the 18F phantom images. The TACs represented a linearity was kept for approximately 10 times of the half-life, that is the quantitatively dynamic rage of PETIS had between from 20 kBq to 20 MBq, strictly.
諏訪 竜一*; 藤巻 秀; 鈴井 伸郎; 河地 有木; 石井 里美; 阪本 浩一*; Nguyen, N. T.*; 実岡 寛文*; Mohapatra, P. K.*; Moghaieb, R. E.*; et al.
Plant Science, 175(3), p.210 - 216, 2008/09
被引用回数:18 パーセンタイル:45.09(Biochemistry & Molecular Biology)Salinity stress affects photosynthate partitioning between sources and sinks of plants, but how it affects on these systems is less understood. Because sources and sinks are closely knitted, any adverse effect under sub-optimal condition on one part is often misinterpreted for the other. Knowledge on regulation of carbon partitioning is indispensable for stress resistance and good plant growth. In the present study, alteration of carbon partitioning in tomato plants (lycopersicon esculentum L. cv. Momotarou) under saline (NaCl) environment was studied by feeding radioactive C and stable C isotopes. Pulse chases were conducted for measuring spatial and temporal distributions of C. C was measured by standard conventional technique, but C distribution was monitored using by PETIS. Salt stress resulted in reduced carbon translocation towards roots. Majority of the photosynthate accumulated in the leaf. We have also observed that the reduction in translocation of carbon occurred well before salt stress symptoms of reduced photosynthesis and plant growth in salt exposed plants. The effect on sink activity also showed by decrease in stem diameter and reduced photosynthetic activity. In addition, PETIS analysis of C translocation indicates that carbon translocation to roots was inhibited under salt conditions without direct effect of leaf Na accumulation and osmotic stress These results suggest that NaCl has direct effects on plants inhibiting carbon partitioning within few hours of salt solution exposure without inhibition of source activity.
片渕 竜也*; 渡辺 智; 石岡 典子; 飯田 靖彦*; 花岡 宏史*; 遠藤 啓吾*; 松橋 信平
Journal of Radioanalytical and Nuclear Chemistry, 277(2), p.467 - 470, 2008/08
被引用回数:36 パーセンタイル:89.51(Chemistry, Analytical)The radionuclide Cu was produced via the Zn(p,2p) Cu reaction by irradiating enriched Zn targets with 70-MeV proton beam. Cu was chemically separated from target zinc material by an ion-exchange chromatography method using Chelex-100 chelating ion-exchange resin. Procedure for recovery of the enriched Zn was developed. The target recovery yield in this method was evaluated to be more than 97%.
河地 有木; 藤巻 秀; 阪本 浩一*; 石岡 典子; 松橋 信平; 関本 均*
Soil Science and Plant Nutrition, 54(3), p.408 - 416, 2008/06
被引用回数:10 パーセンタイル:29.26(Plant Sciences)全寄生性のオロバンキ()は植物根に寄生し農業生産に多大な被害を及ぼしており、そのメカニズムの解明は的確な防除法の確立にとどまらず植物生理学上有用である。本研究ではホスト植物根の窒素栄養の収奪を非侵襲的に可視化し、その収奪率を定量解析することを目的とし、ポジトロンイメージング法(PETIS)において複数核種(NO, F)を用いた解析手法を確立した。オロバンキをアカクローバー根茎に寄生させNOに続いてFを吸収させて、オロバンキへの分配と茎葉基部への移行を可視化し各トレーサの動態を数理解析した。その結果、73.63.9%の窒素栄養素収奪率が定量された。本手法は短半減期核種による繰り返し計測が可能なPETISの特色を活かした新たな解析法であり、得られる定量値は根寄生植物によるホスト植物からの栄養素の収奪を明らかにし、さらには寄生植物の生存戦略や宿主認識メカニズムまでも"可視化"するものである。
松橋 信平
検査技術, 13(5), p.15 - 23, 2008/05
植物ポジトロンイメージング技術は、植物が必要とする栄養成分や有害な環境汚染物などが植物により吸収・輸送される様子をその場観察できるユニークな研究手法である。本稿においては、その特徴とコメの汚染が問題となるカドミウムがイネに吸収される様子の可視化に成功した研究事例などについて解説する。