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Journal Articles

Estimation of external dose for wild Japanese macaques captured in Fukushima prefecture; Decomposition of electron spin resonance spectrum

Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.

Radiation Protection Dosimetry, 199(14), p.1620 - 1625, 2023/09

We have been conducting dose assessments for Japanese macaques captured in Fukushima to reveal radiobiological effects on the low-dose expose animals. To accurately determine the external exposure dose, it is desirable to examine the analysis of the CO$$_{2}^{-}$$ radical intensity. We examined ESR spectra of teeth of 10 macaques captured in Fukushima by two spectrum-decomposition algorithms.

Journal Articles

A Study on accuracy of analysis of the radiation-induced component in the ESR spectra of teeth

Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.

KEK Proceedings 2022-2, p.120 - 125, 2022/11

We investigate the effect of sample's anisotropy and measurement condition to obtain the higher reproducibility for the shape of the ESR spectrum and the intensity of CO$$_{2}^{-}$$ radical.

Journal Articles

Radiation exposure and oxidative stress status of wild Japanese macaques in the ex-evacuation zone of the Fukushima Daiichi Nuclear Power Plant accident

Ishikawa, Ryoya*; Suzuki, Masatoshi*; Kino, Yasushi*; Endo, Satoru*; Nakajima, Hiroo*; Oka, Toshitaka; Takahashi, Atsushi*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Shinoda, Hisashi*; et al.

KEK Proceedings 2022-2, p.61 - 66, 2022/11

The balance between oxidative stress and antioxidant activity, which is a defense mechanism against oxidative stress, was investigated in the liver and bladder of wild Japanese macaques captured in Fukushima Prefecture. No significant induction of oxidative stress by exposure to environmental radionuclides after the Fukushima nuclear accident was observed, suggesting that the stress defense mechanism of the organism is activated in some organs.

Journal Articles

Development of dose estimation method using wild animal teeth for low dose exposure

Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.

KEK Proceedings 2021-2, p.91 - 96, 2021/12

We examined whether the ESR dose estimation method could be applied to wild Japanese macaque. In this work, we investigated the enamel preparation protocol and the analytical method of the ESR spectra.

Journal Articles

Morphological reproductive characteristics of testes and fertilization capacity of cryopreserved sperm after the Fukushima accident in raccoon (${it Procyon lotor}$)

Komatsu, Kazuki*; Iwasaki, Tsugumi*; Murata, Kosuke*; Yamashiro, Hideaki*; Goh, V. S. T.*; Nakayama, Ryo*; Fujishima, Yohei*; Ono, Takumi*; Kino, Yasushi*; Shimizu, Yoshinaka*; et al.

Reproduction in Domestic Animals, 56(3), p.484 - 497, 2021/03

 Times Cited Count:9 Percentile:88.06(Agriculture, Dairy & Animal Science)

We have established an archive system of livestock and wild animals from the surrounding ex-evacuation zone. Wildlife within the alert zone have been exposed to low-dose-rate (LDR) radiation for a long and continuous time. In this study, we analysed the morphological characteristics of the testes and in vitro fertilization (IVF) capacity of cryopreserved sperm of raccoons from the ex-evacuation zone of the FDNPP accident. This study revealed that the chronic and LDR radiation exposure associated with the FDNPP accident had no adverse effect on the reproductive characteristics and functions of male raccoons.

Journal Articles

External exposure dose estimation by electron spin resonance technique for wild Japanese macaque captured in Fukushima Prefecture

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; et al.

Radiation Measurements, 134, p.106315_1 - 106315_4, 2020/06

 Times Cited Count:4 Percentile:54.54(Nuclear Science & Technology)

The relationship between the CO$$_{2}$$ radical intensity and the absorbed dose (dose response curve) of tooth enamel of Japanese macaque was observed by electron spin resonance and the detection limit of our system was estimated to be 33.5 mGy, which is comparable to the detection limit for human molar teeth. Using the dose response curve, external exposure dose for seven wild Japanese macaques captured in Fukushima prefecture were examined. The results suggest that the external exposure dose for the wild Japanese macaques were ranged between 45 mGy to 300 mGy.

Journal Articles

Synergistic extraction of Am(III) and Eu(III) by tris(2-pyridylmethyl)amine with various anions in 1,2-dichloroethane

Ishimori, Kenichiro; Watanabe, Masayuki; Yaita, Tsuyoshi; Kimura, Takaumi; Yamada, Takashi*; Shinoda, Satoshi*; Tsukube, Hiroshi*

Solvent Extraction and Ion Exchange, 27(4), p.489 - 500, 2009/07

 Times Cited Count:4 Percentile:22.31(Chemistry, Multidisciplinary)

The remarkable enhancements of the extraction efficiency of Am(III) and Eu(III) and the separation efficiency between Am(III) and Eu(III) were achieved through changes in counter anions and/or organic solvents, in the solvent extraction of Am(III) and Eu(III) with a tripodal ligand, tris(2-pryidylmethyl)amine (tpa). The separation factor (Am/Eu), which is defined as the ratio between the distribution ratios of Am(III) and Eu(III), ranged from 10 to 50 using various combinations of counter anions and organic solvents. The extraction equilibria of Am(III) and Eu(III) with tpa in 1,2-dichloroethane were determined in detail through slope analyses in order to elucidate the mechanism of separation and identify the extracted species.

Journal Articles

Novel separation system of trivalent actinides-combined effects of substituted tris(2-pyridylmethyl)amine ligand and hydrophobic counter-anion

Ishimori, Kenichiro*; Watanabe, Masayuki; Kimura, Takaumi; Yaita, Tsuyoshi; Yamada, Takashi*; Kataoka, Yumiko*; Shinoda, Satoshi*; Tsukube, Hiroshi*

Chemistry Letters, 34(8), p.1112 - 1113, 2005/08

 Times Cited Count:13 Percentile:44.83(Chemistry, Multidisciplinary)

Stereochemical substitution on tripod ligand significantly offered efficient separation of trivalent actinides from trivalent lanthanides. Liquid-liquid extraction using chiral tris(2-pyridylmethyl)amine ligands as an extractant exhibited high efficiency and selectivity for trivalent actinides. A combination of chiral ligand and 2-bromodecanoic acid further enhanced extraction performance for trivalent actinides.

Journal Articles

AC loss performance of the 100kwh SMES model coil

Hamajima, Takataro*; Hanai, Satoshi*; Wachi, Yoshihiro*; Shimada, Mamoru*; Ono, Michitaka*; Martovetsky, N.*; Zbasnik, J.*; Moller, J.*; Takahashi, Yoshikazu; Matsui, Kunihiro; et al.

IEEE Transactions on Applied Superconductivity, 10(1), p.812 - 815, 2000/03

 Times Cited Count:10 Percentile:53.58(Engineering, Electrical & Electronic)

no abstracts in English

Journal Articles

Test results of the SMES model coil; Pulse performance

Hamajima, Takataro*; Shimada, Mamoru*; Ono, Michitaka*; Takigami, Hiroyuki*; Hanai, Satoshi*; Wachi, Yoshihiro*; Takahashi, Yoshikazu; Matsui, Kunihiro; Ito, Toshinobu*; Isono, Takaaki; et al.

Teion Kogaku, 33(7), p.492 - 499, 1998/00

no abstracts in English

Oral presentation

Separation of Am(III) by nitrogen-donor ligand

Watanabe, Masayuki; Ishimori, Kenichiro; Wada, Atsushi*; Kataoka, Yumiko*; Murata, Masaki*; Shinoda, Satoshi*; Nishihara, Hiroshi*; Tsukube, Hiroshi*; Kimura, Takaumi

no journal, , 

Soft-donor extractants containing sulfur- or nitrogen-donor are applicable to the separation of trivalent actinides (An(III)) from lanthanides (Ln(III)) by solvent extraction method. We designed two ligand systems which are expected to efficiently separate An(III) from Ln(III). The one is "Oligo-pyridine" ligand containing multiple pyridine moieties. The other is "Chirality-controlled" ligand containing chiral centers in the ligand. We synthesized more than thirty ligands and found out the ability on the separation of An(III) from Ln(III). In this presentation, we will discuss about the comprehensive results on the separation ability of An(III) from Ln(III) by means of "Oligo-pyridine" and "Chirality-controlled" ligands, and the extraction equilibrium of An(III) with selected tripodal ligands in detail.

Oral presentation

Present status of R&D on nuclear forensics at JAEA

Sakurai, Satoshi; Kimura, Yoshiki; Sato, Kaneaki; Toda, Nobufumi; Shinoda, Yoshiharu; Okubo, Ayako; Magara, Masaaki; Watahiki, Masaru; Kuno, Yusuke

no journal, , 

The national statement made by the Japan Government at 2010 Nuclear Security Summit (Washington D.C., U.S.A.) was to develop its nuclear forensics detection and analysis technologies in a three-year period and to share them with the international community to contribute to strengthening the nuclear security regime. The Japan Atomic Energy Agency, the organization that possesses analytical capabilities with the potential to fulfill this nuclear forensics mission, started R&D on nuclear forensics technology from JFY 2011. The main areas of development are isotopic ratio analysis, impurity analysis, uranium age determination, etc. The cooperation with US-DOE and EC-JRC were also started to effectively promote the technical development. In the presentation reported will be progress in R&D to establish nuclear forensics analytical capabilities and international cooperation.

Oral presentation

External dose estimation of Japanese macaque and Procyon lotor using electron spin resonance spectroscopy

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Ono, Takumi*; Tamaki, Hiroaki*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.

no journal, , 

Releases of the radioactive materials from the Fukushima Daiichi Nuclear Power Plant accident result in an ionization exposure to people and animals, the precise dosimetry is required. To estimate the external dose due to the accident, we utilize electron spin resonance (ESR) spectroscopy which is a powerful tool for the dosimetry of external dose. The detection limit of this technique was 146 mGy, so that we have to improve the detection limit for the precise dosimetry. In this work, we developed a novel enamel-dentine separation technique and improved the detection limit down to 43 mGy, and estimated the external dose for Japanese macaque and Procyon lotor collected in Fukushima prefecture.

Oral presentation

Sample preparation procedure for the estimation of external exposure dose of wild animals using elecron spin resonance spectroscopy

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Ono, Takumi*; Tamaki, Hiroaki*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.

no journal, , 

Release of the radioactive materials from Fukushima Daiichi Nuclear Power Plant accident results in a long-term low dose rate ionization exposure to wild animals. The biological effects of the wild animal do not show a clear correlation with the external dose, which is estimated from the external dose rate of the captured point of the animal, a precise external dose estimation using ESR and tooth enamel is required instead of using the external dose rate. In this work, we attempted to estimate the external dose of wild Japanese macaque and Procyon lotor captured in the high dose rate area.

Oral presentation

External exposure dose of Japanese macaque captured in Fukushima prefecture

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; et al.

no journal, , 

Due to the Fukushima Daiichi Nuclear Power Plant accident, the exposure dose estimation for human is examined by the whole body counter or by the Fukushima Health Management Survey, however, the precise estimated dose cannot obtained by such methods. We applied electron spin resonance (ESR) dosimetry for the external dose estimation using tooth enamel of human/animal. As we reported last year, we improved the detection limit of ESR dosimetry down to 43 mGy. We used this improved ESR dosimetry system and attempted to estimate the external dose of wild Japanese macaque capture in Fukushima prefecture, however, the metal component which may obstruct the ESR measurement was observed, so that we cannot estimate the external dose. In this work, we investigated how to remove such metal components, obtain the clear ESR spectrum, and estimate the external dose.

Oral presentation

Sample preparation procedure for ESR dosimetry using teeth of wild animal

Oka, Toshitaka; Mitsuyasu, Yusuke*; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Sekine, Tsutomu*; Okutsu, Kenichi*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.

no journal, , 

Releases of the radioactive materials from the Fukushima Daiichi Nuclear Power Plant accident result in a low dose exposure to wild animals. The external dose of wild animals is commonly estimated by the external dose rate of the captured point, but the estimated exposure dose has huge uncertainties because the size of the habitat and/or the movement of the wild animals are not included in the estimation. To estimate the external dose precisely, we utilize electron spin resonance (ESR) dosimetry. In this work, we investigated the sample preparation procedure of wild animals. The ESR spectrum of enamel of racoon captured in Namie-town, Fukushima has a broad ESR signal due to metal components. The linear relationship between the Co$$_{2}$$ intensity and the absorbed dose that we can apply ESR dosimetry for racoon teeth. Using this relationship, the external exposure dose was estimated.

Oral presentation

Dose estimation for animals exposed low dose using their teeth

Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.

no journal, , 

The improvement of the ESR dosimetry is required to apply that for the low-dose exposure of wild animals. We will report our progress of the improvement, and compare the external exposure dose estimated by the ESR dosimetry technique and the calculated result based on the external exposure dose rate of the captured point.

Oral presentation

Assessment of chromosome translocation in wild Japanese macaques in Fukushima

Fujishima, Yohei*; Suzuki, Masatoshi*; Goh, V. S. T.*; Ariyoshi, Kentaro*; Kasai, Kosuke*; Nakata, Akifumi*; Kino, Yasushi*; Oka, Toshitaka; Shinoda, Hisashi*; Shimizu, Yoshinaka*; et al.

no journal, , 

After the Fukushima Daiichi Nuclear Power Plant accident, the surrounding environment was contaminated with radionuclides. Although the ambient dose rates are decreasing, prolonged effects of chronic low-dose exposure on animals are expected to be seen in the coming years. It is necessary to assess the effects of radioactivity on the wild animals in this area to better understand about the risk of low dose radiation. The chromosome translocation frequency of Japanese macaques were significantly higher in Fukushima groups comparing from control groups in Miyagi. Furthermore, chromosome translocation frequencies tended to correlate between external doses or internal dose-rates. However, chromosome translocation frequency was decreasing year by year, which may reflect restoration of environments such as decreasing of ambient dose-rates and decontamination efforts.

Oral presentation

External exposure dose estimation using ESR dosimetry technique

Oka, Toshitaka; Takahashi, Atsushi*; Mitsuyasu, Yusuke*; Koarai, Kazuma; Kino, Yasushi*; Okutsu, Kenichi*; Yamashita, Takuma*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.

no journal, , 

Electron spin resonance (ESR) dosimetry technique is a powerful tool that has been used in the study of external exposure dose assessment of human by measuring CO$$_{2}$$ radicals of teeth. In this work, we applied this technique for wild monkey and wild racoon captured in Fukushima prefecture, and estimated the external exposure dose.

Oral presentation

Influence on the oxidative stress status in liver and bladder of wild Japanese macaques in response to radiation exposure in the ex-evacuation zone of the Fukushima Daiichi Nuclear Power Plant accident

Ishikawa, Ryoya*; Suzuki, Masatoshi*; Kino, Yasushi*; Endo, Satoru*; Nakajima, Hiroo*; Oka, Toshitaka; Takahashi, Atsushi*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Shinoda, Hisashi*; et al.

no journal, , 

In order to investigate the influence on the oxidative stress status by the long-term exposure after the Fukushima Daiichi Nuclear power plant (FNPP) accident, we analyzed oxidative stress markers in liver and bladder of wild Japanese macaques in the ex-evacuation zone. In liver, the concentration of malondialdehyde (MDA) in approximately 70% of the exposed group exceeded the average and SOD activity of the exposed group shifted toward lower within the range indicated in the control group. By contrast, alteration of MDA concentration and SOD activity in bladder was opposite to that shown in liver. We also found that oxidative stress markers changed in the same manner by external and internal exposure. Our data suggested that exposure to low dose/low dose-rate radiation following the FNPP accident may affect the sensitivity to oxidative stress by changing the activity of antioxidant enzymes.

22 (Records 1-20 displayed on this page)