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Kurita, Keisuke; Sakai, Takuro; Suzui, Nobuo*; Yin, Y.-G.*; Sugita, Ryohei*; Kobayashi, Natsuko*; Tanoi, Keitaro*; Kawachi, Naoki*
Japanese Journal of Applied Physics, 60(11), p.116501_1 - 116501_4, 2021/11
Times Cited Count：1 Percentile：7.86(Physics, Applied)Radioisotope tracer imaging is useful for studying plant physiological phenomena. In this study, we developed an autoradiography system with phosphor powder (ZnS:Ag), "Live-autoradiography", for imaging radioisotope dynamics in a living plant. This system visualizes the element migration and accumulation in intact plants continuously under a light environment. An imaging test was performed on point sources of 
Cs, with a radioactivity of 10-100 kBq of being observed; this indicates satisfactory system linearity between the image intensity and the radioactivity of Cs. Moreover, dynamics imaging of Cs was performed on an intact soybean plant for four days. The serial images indicated Cs accumulation in the node, vein, and growing point of the plant. The developed system can be used for studying plant physiological phenomena and can be employed for quantitative measurement of radionuclides.
Nihei, Naoto*; Yoshimura, Kazuya; Okumura, Taiga*; Tanoi, Keitaro*; Iijima, Kazuki; Kogure, Toshihiro*; Nakanishi, Tomoko*
Journal of Radioanalytical and Nuclear Chemistry, 318(1), p.341 - 346, 2018/10
Times Cited Count：4 Percentile：38.58(Chemistry, Analytical)Mukai, Hiroki*; Hirose, Atsushi*; Motai, Satoko*; Kikuchi, Ryosuke*; Tanoi, Keitaro*; Nakanishi, Tomoko*; Yaita, Tsuyoshi; Kogure, Toshihiro*
Scientific Reports (Internet), 6, p.21543_1 - 21543_7, 2016/02
Times Cited Count：133 Percentile：96.62(Multidisciplinary Sciences)Yin, Y.-G.; Suzui, Nobuo; Kawachi, Naoki; Yamaguchi, Mitsutaka; Tanoi, Keitaro*; Ishii, Satomi; Nakanishi, Tomoko*; Chino, Mitsuo*; Nakamura, Shinichi*; Watabe, Hiroshi*; et al.
Hoshasen To Sangyo, (133), p.45 - 48, 2012/12
no abstracts in English
Yin, Y.-G.; Suzui, Nobuo; Yamaguchi, Mitsutaka; Kawachi, Naoki; Tanoi, Keitaro*; Nakanishi, Tomoko*; Chino, Mitsuo*; Nakamura, Shinichi*; Fujimaki, Shu
Nihon Dojo Hiryo Gaku Zasshi, 83(3), p.296 - 300, 2012/06
no abstracts in English
Tanoi, Keitaro*; Hamada, Yosuke*; Seyama, Shohei*; Saito, Takayuki*; Iikura, Hiroshi; Nakanishi, Tomoko*
Nuclear Instruments and Methods in Physics Research A, 605(1-2), p.179 - 184, 2009/06
Times Cited Count：3 Percentile：28.22(Instruments & Instrumentation)Oya, Tomoyuki*; Rai, Hiroki*; Tanoi, Keitaro*; Iikura, Hiroshi; Nakanishi, Tomoko*
Radioisotopes, 56(11), p.729 - 736, 2007/11
To study the effect of rhizosphere pH on the cadmium(Cd) uptake, soybean seedlings were grown for 4 days in 0.2 mM CaCl
solution containing 1 
M Cd under pH 4.5 or pH 6.5 using 
Cd as a tracer. The concentration of Cd in root at pH 6.5 was 3.4 times higher than that at pH 4.5. Cadmium amount absorbed on root surface at pH 6.5 was 1.3 times higher than that at pH 4.5. With high accumulation of Cd in root, Cd toxicity such as brownish of the tissue and the suppression of lateral root development was only observed under pH 6.5 condition. Transpiration rate was found to have no relation to high accumulation of Cd in shoot.
F-labeled water movement in a cowpea plant by positron emitting tracer imaging system (PETIS)Furukawa, Jun*; Yokota, Harumi*; Tanoi, Keitaro*; Ueoka, Shiori*; Matsuhashi, Shimpei; Ishioka, Noriko; Watanabe, Satoshi; Uchida, Hiroshi*; Tsuji, Atsunori*; Ito, Takehito*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 249(2), p.495 - 498, 2001/08
Times Cited Count：16 Percentile：73.21(Chemistry, Analytical)We present real time Vanadate (V
) uptake imaging in a cowpea plant by Positron Emitting Tracer Imaging System (PETIS). Vanadium-48 was produced by bombarding a Sc foil target with 50 MeV 
-particles at Takasaki Ion accelerators for Advanced Radiation Application (TIARA) AVF cyclotron. Then 
V was added to the culture solution to investigate the V distribution in a cowpea plant. The real time uptake of the V was monitored by PETIS. We measured the distribution of V in a whole plant after 3, 6 and 20 hours of V treatment by Bio-imaging Analyzer System (BAS). After the 20 hour treatment, vanadate was detected at the up-ground part of the plant. To know the effect of V uptake on plant activity, F-labeled water uptake was analyzed by PETIS. When a cowpea plant was treated with V for 20 hours before F-labeled water uptake experiment, the total amount of F-labeled water absorption was drastically desreased. Results suggest the inhibition of water uptake was mainly caused by the vanadate already moved to the up-ground part of the plant.
F used as tracer to study water uptake and transport imaging of a cowpea plantNakanishi, Tomoko*; Tanoi, Keitaro*; Yokota, Harumi*; Kang, D.-J.*; Ishii, Ryuichi*; Ishioka, Noriko; Watanabe, Satoshi; Osa, Akihiko; Sekine, Toshiaki; Matsuhashi, Shimpei; et al.
Journal of Radioanalytical and Nuclear Chemistry, 249(2), p.503 - 507, 2001/08
We present the water uptake ability of cowpea (
) which has been regarded as one of the most drought resistant species among the pulse crops. It has been suggested that in the lower part of the stem, parenchymatous tissue for storing water had been developed for the function of deought resistance. We confirmed that in this tissue, water amount was high compared to the other stems by neutron radiography. Then the water uptake manner was measured by positron emitting tracer imaging system (PETIS) using F labeled water produced by a cyclotron. Comparing the water uptake manner of cowpea plant with that of common bean, cowpea plant was found to maintain high water uptake activity after drying treatment, suggesting the high drought resistant character.
O-labeled and F-labeled water uptake in a soybean plant by PETIS (Positron Emitting Tracer Imaging System)Nakanishi, Tomoko*; Yokota, Harumi*; Tanoi, Keitaro*; Ikeue, Natsuko*; Okuni, Yoko*; Furukawa, Jun*; Ishioka, Noriko; Watanabe, Satoshi; Osa, Akihiko; Sekine, Toshiaki; et al.
Radioisotopes, 50(6), p.265 - 269, 2001/06
O-Labeled and F-Labeled water uptake manner in a soybean plant was compared by PETIS (Positron Emitting Tracer Imaging System). O-Labeled water (half-life: 2 min) and F-Labeled water (half-life: 110 min) were produced by a cyclotron by 
N(d,n)O and 
O(,pn)F reactions, respectively. A root of a soybean plant was cut off and each labeled water was supplied from the basal part of the plant. The gamma-rays emitted from the sample was measured by a BGO counter with a detection area of 5 cm
15 cm. The radioactivity from each stem was accumlated every 15 s till 20 min. It was found that F-labeled water was taken up much faster than O-labeled water, suggesting that in F-labeled water, fluorine was moved in the form of F-ion. When BAS image of O-labeled water in a plant after 5 min and 10 min of water supply was taken, it was found that the labeled water was observed only in the lowest internode, between a root and the first leaves.
Yin, Y.-G.; Suzui, Nobuo; Yamaguchi, Mitsutaka; Kawachi, Naoki; Tanoi, Keitaro*; Nakanishi, Tomoko*; Chino, Mitsuo*; Nakamura, Shinichi*; Fujimaki, Shu
no journal, ,
no abstracts in English
cameraYin, Y.-G.; Kawachi, Naoki; Suzui, Nobuo; Ishii, Satomi; Yamaguchi, Mitsutaka; Tanoi, Keitaro*; Nakanishi, Tomoko*; Chino, Mitsuo*; Nakamura, Shinichi*; Watabe, Hiroshi*; et al.
no journal, ,
no abstracts in English
Yin, Y.-G.; Suzui, Nobuo; Yamaguchi, Mitsutaka; Kawachi, Naoki; Tanoi, Keitaro*; Nakanishi, Tomoko*; Chino, Mitsuo*; Nakamura, Shinichi*; Fujimaki, Shu
no journal, ,
no abstracts in English
Yin, Y.-G.; Suzui, Nobuo; Kawachi, Naoki; Yamaguchi, Mitsutaka; Tanoi, Keitaro*; Nakanishi, Tomoko*; Chino, Mitsuo*; Nakamura, Shinichi*; Watabe, Hiroshi*; Yamamoto, Seiichi*; et al.
no journal, ,
no abstracts in English
Yin, Y.-G.; Suzui, Nobuo; Yamaguchi, Mitsutaka; Kawachi, Naoki; Tanoi, Keitaro*; Nakanishi, Tomoko*; Chino, Mitsuo*; Nakamura, Shinichi*; Fujimaki, Shu
no journal, ,
no abstracts in English
Yin, Y.-G.; Suzui, Nobuo; Yamaguchi, Mitsutaka; Kawachi, Naoki; Tanoi, Keitaro*; Nakanishi, Tomoko*; Chino, Mitsuo*; Nakamura, Shinichi*; Fujimaki, Shu
no journal, ,
There is very high demand for analysis of radiocesium content in contaminated samples such as soils and foods. NaI(Tl) scintillation spectrometer can be a most promising tool for this situation because it has advantages compared to Ge semiconductor detector, that is, lower price, small size and light weight, and easy handling. However, NaI(Tl) scintillation spectrometer has a critical disadvantage that it cannot completely distinguish the rays emitted by Cs-134 and Cs-137 and thus has difficulty to measure Cs-134 and Cs-137 selectively. In this study, we propose a simple method to determine the amounts of Cs-134 and Cs-137 separately without any special software, based on the spectral data obtained with NaI(Tl) scintillation spectrometer. Several samples from contaminated fields were subjected to this method and the results successfully showed high consistency (87% - 106%) with the values obtained with Ge semiconductor detector, for the respective nuclides.
Tanaka, Takuro*; Saito, Takumi*; Toda, Kanako*; Fujiwara, Kenso; Terashima, Motoki; Nakanishi, Takahiro; Kobayashi, Natsuko*; Tanoi, Keitaro*
no journal, ,
Cs-137 dispersed by the Fukushima Daiichi Nuclear Power Plant accident deposited in Fukushima area, that are not decontaminated in mountainous areas, may migrate through river water to animals and plants. Most of Cs-137 in river are fixed in clay minerals, but there are some Cs that can be easily desorbed, named as labile components. It has been suggested that labile components affect the bioavailability of Cs-137. In this study, the labile Cs-137 was sampled in situ from upstream to downstream in several rivers of Fukushima using a passive sampler called diffusive gradients in thin films (DGT). Sampling was conducted at a different season in addition to the previous studies.
Cs in Fukushima rivers by diffusive gradients in thin films (DGT), 3; Relations between geochemical parametersTanaka, Takuro*; Saito, Takumi*; Toda, Kanako*; Fujiwara, Kenso; Terashima, Motoki; Nakanishi, Takahiro; Kobayashi, Natsuko*; Tanoi, Keitaro*; Kato, Hiroaki*
no journal, ,
Cs dispersed by the Fukushima Daiichi Nuclear Power Plant accident deposited in Fukushima area, that are not decontaminated in mountainous areas, may migrate through river water to animals and plants. Most of Cs in river are fixed in clay minerals, but there are some Cs that can be easily desorbed, named as labile components. It has been suggested that labile components affect the bioavailability of Cs. In this study, the labile Cs was sampled in situ from upstream to downstream in several rivers of Fukushima using a passive sampler called diffusive gradients in thin films (DGT). The desorption behavior of the labile component and factors affecting it will be discussed by examining the relationship with particulate Cs and geochemical parameters in river water.
