Faculty Profiles - HANAMOTO Katsumi

Papers - HANAMOTO Katsumi

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A simple method for estimating the potential of the pyroelectric crystal surface

Katsumi Hanamoto, Takahiro Kataoka, Kiyonori Yamaoka

Applied Radiation and Isotopes 185 110230 - 110230 2022.7

Erratum to: Evaluation of the redox state in mouse organs following radon inhalation. International journal

Takahiro Kataoka, Norie Kanzaki, Akihiro Sakoda, Hina Shuto, Junki Yano, Shota Naoe, Hiroshi Tanaka, Katsumi Hanamoto, Hiroaki Terato, Fumihiro Mitsunobu, Kiyonori Yamaoka

Journal of radiation research 62 ( 5 ) 945 - 945 2021.9

Radon inhalation decreases DNA damage induced by oxidative stress in mouse organs via the activation of antioxidative functions. International journal

Takahiro Kataoka, Hina Shuto, Shota Naoe, Junki Yano, Norie Kanzaki, Akihiro Sakoda, Hiroshi Tanaka, Katsumi Hanamoto, Fumihiro Mitsunobu, Hiroaki Terato, Kiyonori Yamaoka

Journal of radiation research 62 ( 5 ) 861 - 867 2021.8

Language：English Publishing type：Research paper (scientific journal)

Radon inhalation decreases the level of lipid peroxide (LPO); this is attributed to the activation of antioxidative functions. This activation contributes to the beneficial effects of radon therapy, but there are no studies on the risks of radon therapy, such as DNA damage. We evaluated the effect of radon inhalation on DNA damage caused by oxidative stress and explored the underlying mechanisms. Mice were exposed to radon inhalation at concentrations of 2 or 20 kBq/m3 (for one, three, or 10 days). The 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels decreased in the brains of mice that inhaled 20 kBq/m3 radon for three days and in the kidneys of mice that inhaled 2 or 20 kBq/m3 radon for one, three or 10 days. The 8-OHdG levels in the small intestine decreased by approximately 20-40% (2 kBq/m3 for three days or 20 kBq/m3 for one, three or 10 days), but there were no significant differences in the 8-OHdG levels between mice that inhaled a sham treatment and those that inhaled radon. There was no significant change in the levels of 8-oxoguanine DNA glycosylase, which plays an important role in DNA repair. However, the level of Mn-superoxide dismutase (SOD) increased by 15-60% and 15-45% in the small intestine and kidney, respectively, following radon inhalation. These results suggest that Mn-SOD probably plays an important role in the inhibition of oxidative DNA damage.

DOI： 10.1093/jrr/rrab069

The Effects of Low-Dose-Rate γ-irradiation on Forced Swim Test-Induced Immobility and Oxidative Stress in Mice.

Tetsuya Nakada, Takahiro Kataoka, Takaharu Nomura, Hina Shuto, Junki Yano, Shota Naoe, Katsumi Hanamoto, Kiyonori Yamaoka

Acta medica Okayama 75 ( 2 ) 169 - 175 2021.4

Language：English Publishing type：Research paper (scientific journal)

The forced swim test (FST) induces immobility in mice. Low-dose (high-dose-rate) X-irradiation inhibits FSTinduced immobility in mice due to its antioxidative function. We evaluated the effects of low-dose γ-irradiation at a low-dose-rate on the FST-induced depletion of antioxidants in mouse organs. Mice received whole-body low-dose-rate (0.6 or 3.0 mGy/h) of low-dose γ-irradiation for 1 week, followed by daily FSTs (5 days). The immobility rate on day 2 compared to day 1 was significantly lower in the 3.0 mGy/h irradiated mice than in sham irradiated mice. The FST significantly decreased the catalase (CAT) activity and total glutathione (t-GSH) content in the brain and kidney, respectively. The superoxide dismutase (SOD) activity and t-GSH content in the liver of the 3.0 mGy/h irradiated mice were significantly lower than those of the non-FST-treated mice. The CAT activity in the lungs of mice exposed to 3.0 mGy/h γ-irradiation was higher than that of non-FST treated mice and mice treated with FST. However, no significant differences were observed in the levels of these antioxidant markers between the sham and irradiated groups except for the CAT activity in lungs. These findings suggest that the effects of low-dose-rate and low-dose γ-irradiation on FST are highly organ-dependent.

DOI： 10.18926/AMO/61896

Evaluation of the redox state in mouse organs following radon inhalation

Takahiro Kataoka, Norie Kanzaki, Akihiro Sakoda, Hina Shuto, Junki Yano, Shota Naoe, Hiroshi Tanaka, Katsumi Hanamoto, Hiroaki Terato, Fumihiro Mitsunobu, Kiyonori Yamaoka

Journal of radiation research 62 ( 2 ) 206 - 216 2021.3

Publishing type：Research paper (scientific journal)

Radon inhalation activates antioxidative functions in mouse organs, thereby contributing to inhibition of oxidative stress-induced damage. However, the specific redox state of each organ after radon inhalation has not been reported. Therefore, in this study, we evaluated the redox state of various organs in mice following radon inhalation at concentrations of 2 or 20 kBq/m3 for 1, 3 or 10 days. Scatter plots were used to evaluate the relationship between antioxidative function and oxidative stress by principal component analysis (PCA) of data from control mice subjected to sham inhalation. The results of principal component (PC) 1 showed that the liver and kidney had high antioxidant capacity; the results of PC2 showed that the brain, pancreas and stomach had low antioxidant capacities and low lipid peroxide (LPO) content, whereas the lungs, heart, small intestine and large intestine had high LPO content but low antioxidant capacities. Furthermore, using the PCA of each obtained cluster, we observed altered correlation coefficients related to glutathione, hydrogen peroxide and LPO for all groups following radon inhalation. Correlation coefficients related to superoxide dismutase in organs with a low antioxidant capacity were also changed. These findings suggested that radon inhalation could alter the redox state in organs; however, its characteristics were dependent on the total antioxidant capacity of the organs as well as the radon concentration and inhalation time. The insights obtained from this study could be useful for developing therapeutic strategies targeting individual organs.

DOI： 10.1093/jrr/rraa129

ラドン吸入によるマウス諸臓器中のDNA酸化損傷抑制の濃度依存に関する検討．

増川祐伎, 光延文裕, 寺東宏明, 山岡聖典, 片岡隆浩, 首藤妃奈, 直江翔太, 矢野凖喜, 神崎訓枝, 迫田晃弘, 田中裕史, 花元克巳

アイソトープ・放射線研究発表会 1 86 - 86 2021

Language：Japanese Publisher：公益社団法人日本アイソトープ協会

<p>ラドン吸入によるマウス諸臓器中のDNA酸化損傷の抑制について検討した結果，脳や腎臓において抑制することが示唆できた。これに関して，ラドン吸入により抗酸化酵素であるMn-SODの活性が増加しDNAの酸化損傷を抑制する機序や，ラドン濃度依存性のあることも示唆できた。</p>

DOI： 10.50955/happyokai.1.0_86

X-Irradiation at 0.5 Gy after the forced swim test reduces forced swimming-induced immobility in mice

Takahiro Kataoka, Hina Shuto, Junki Yano, Shota Naoe, Tsuyoshi Ishida, Tetsuya Nakada, Keiko Yamato, Katsumi Hanamoto, Takaharu Nomura, Kiyonori Yamaoka

Journal of Radiation Research 61 ( 4 ) 517 - 523 2020.7

Publishing type：Research paper (scientific journal)

The forcedswimtest (FST)is a screeningmodel forantidepressantactivity; it causes immobilityand inducesoxidative stress. We previously reported that radon inhalation has antidepressant-like effects in mice potentially through the activation of antioxidative functions upon radon inhalation. This study aimed to investigate the effect of prior and post low-dose X-irradiation (0.1, 0.5, 1.0 and 2.0 Gy) on FST-induced immobility and oxidative stress in the mouse brain, and the differences, if any, between the two.Mice received X-irradiation before or after the FST repeatedly for 5 days. In the post-FST-irradiated group, an additional FST was conducted 4 h after the last irradiation.Consequently, animals receiving priorX-irradiation (0.1Gy) had better mobility outcomes than sham-irradiatedmice; however, their levels of lipid peroxide (LPO), an oxidative stressmarker, remained unchanged.However, animals that received post- FST X-irradiation (0.5 Gy) had better mobility outcomes and their LPO levels were significantly lower than those of the sham-irradiated mice. The present results indicate that 0.5 Gy X-irradiation after FST inhibits FST-induced immobility and oxidative stress in mice.

DOI： 10.1093/jrr/rraa022

Basic study on enhancement of antioxidant function by low-dose irradiation in mouse brain and its combined effect with ascorbic acid Reviewed

Takahiro KATAOKA, Yuto YUNOKI, Norie KANZAKI, Kaori SASAOKA, Yusuke KOBASHI, Tsuyoshi ISHIDA, Katsumi HANAMOTO, Kiyonori YAMAOKA

RADIOISOTOPES 69 ( 2 ) 45 - 53 2020.2

X線照射によるマウス脳の酸化ストレス状態の変化特性に関する検討

片岡隆浩, 神崎訓枝, 柚木勇人, 小橋佑介, 石田毅, 花元克巳, 山岡聖典

日本放射線影響学会大会講演要旨集 61回 78 - 78 2018.11

Pressure dependence of X-rays produced by an LiTaO3 single crystal over a wide range of pressure

Katsumi Hanamoto, Takahiro Kataoka, Kiyonori Yamaoka

Applied Radiation and Isotopes 135 40 - 42 2018.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier Ltd

The energy spectra of X-rays produced by an LiTaO3 single crystal have been measured at the pressures of 8 × 10−4−4 Pa. The energy spectra showed that the endpoint energy steadily increased with decrease of pressure at 2–4 Pa and gradually decreased with decrease of pressure at 0.1–2 Pa, and became almost constant below 0.1 Pa. The amount of X-rays steadily increased with decrease of pressure at 2–4 Pa and almost saturated below 0.5 Pa. The change of X-rays produced by the LiTaO3 single crystal was compared with the previous works and discussed in relation to the distance between the crystal surface and the target.

DOI： 10.1016/j.apradiso.2018.01.019

Pressure dependence of X-rays produced by an LiTaO3 single crystal at the pressures of 1-20 Pa

Katsumi Hanamoto, Takahiro Kataoka, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 116 134 - 137 2016.10

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The energy spectra of X-rays produced by an LiTaO3 single crystal have been measured at pressures of 1-20 Pa. The energy spectra showed that the endpoint energy and the amount of X-rays gradually increased with the decrease of pressure at 5-8 Pa and abruptly increased around 4 Pa and below. A maximum endpoint energy of 70 keV was obtained using the LiTaO3 single crystal with 5 mm thickness at a pressure of 3 Pa. The change of X-rays produced by the LiTaO(3)single crystal was discussed in relation to the breakdown potential at the pressures. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2016.08.003

Activation of Antioxidative Functions by Radon Inhalation Enhances the Mitigation Effects of Pregabalin on Chronic Constriction Injury-Induced Neuropathic Pain in Mice

Takahiro Kataoka, Shunsuke Horie, Reo Etani, Norie Kanzaki, Kaori Sasaoka, Yusuke Kobashi, Katsumi Hanamoto, Kiyonori Yamaoka

OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016 2016

Language：English Publishing type：Research paper (scientific journal) Publisher：HINDAWI LTD

Radon inhalation brings pain relief for chronic constriction injury- (CCI-) induced neuropathic pain in mice due to the activation of antioxidative functions, which is different from the mechanism of the pregabalin effect. In this study, we assessed whether a combination of radon inhalation and pregabalin administration is more effective against neuropathic pain than radon or pregabalin only. Mice were treated with inhaled radon at a concentration of 1,000 Bq/m(3) for 24 hours and pregabalin administration after CCI surgery. In mice treated with pregabalin at a dose of 3 mg/kg weight, the 50% paw withdrawal threshold of mice treated with pregabalin or radon and pregabalin was significantly increased, suggesting pain relief. The therapeutic effects of radon inhalation or the combined effects of radon and pregabalin (3 mg/kg weight) were almost equivalent to treatment with pregabalin at a dose of 1.4 mg/kg weight or 4.1 mg/kg weight, respectively. Radon inhalation and the combination of radon and pregabalin increased antioxidant associated substances in the paw. The antioxidant substances increased much more in radon inhalation than in pregabalin administration. These findings suggested that the activation of antioxidative functions by radon inhalation enhances the pain relief of pregabalin and that this combined effect is probably an additive effect.

DOI： 10.1155/2016/9853692

Evaluating the protective effects of radon inhalation or ascorbic acid treatment after transient global cerebral ischemic injury in gerbils

Takahiro Kataoka, Reo Etani, Norie Kanzaki, Kaori Sasaoka, Yusuke Kobashi, Katsumi Hanamoto, Takehito Taguchi, Kiyonori Yamaoka

JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY 53 ( 11 ) 1681 - 1685 2016

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

In this study, we compared the protective effects of radon inhalation and ascorbic acid administration on transient global cerebral ischemic injury in gerbils. Gerbils were treated with radon inhalation (2000 Bq/m(3), 24 hours) or ascorbic acid (100, 300, or 500mg/kg body weight). Then, transient global cerebral ischemia was induced by bilateral occlusion of the common carotid artery. Results showed that the number of damaged neurons was significantly increased in gerbils that underwent ischemia compared with that in control gerbils. However, the number of damaged neurons in gerbils treated with radon or 500mg/kg of ascorbic acid before ischemia was significantly lower than gerbils who were subjected to ischemia without any pretreatment, and the protective effects of radon inhalation were similar to the effects of administering 500mg/kg ascorbic acid. The levels of superoxide dismutase (SOD) and total glutathione (t-GSH) in brain tissue were increased to a similar extent by pretreatment with radon inhalation or 500mg/kg of ascorbic acid. These findings suggested that radon inhalation has a protective antioxidative effect against transient global cerebral ischemic injury similar to 500mg/kg ascorbic acid treatment.

DOI： 10.1080/00223131.2016.1198731

Effects of cream containing ultralow volume radionuclides on carrageenan-induced inflammatory paw edema in mice Reviewed

Takahiro Kataoka, Yuji Takata, Reo Etani, Yuichi Nishiyama, Atsushi Kawabe, Katsumi Hanamoto, Takehito Taguchi, Kiyonori Yamaoka

Biochemistry & Physiology 3 ( 2 ) 1 - 5 2014

Radioactivity of Pb-210 in Japanese cigarettes and radiation dose from smoking inhalation

A. Sakoda, K. Fukao, A. Kawabe, T. Kataoka, K. Hanamoto, K. Yamaoka

RADIATION PROTECTION DOSIMETRY 150 ( 1 ) 109 - 113 2012.6

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS

It is well known that cigarette tobaccos contain naturally occurring radioactive nuclides such as Pb-210 and Po-210. In many countries, the radioactivity of tobaccos has been measured to estimate the effective dose from smoking inhalation. The present study covered 24 cigarette brands including the top 20 of sales in Japan between April 2008 and March 2009. The activity concentrations of Pb-210 were measured by gamma-ray spectrometry, and then those of its progeny (Po-210) were evaluated assuming the radioactive equilibrium between the two nuclides. Their concentrations were in the range of 214 mBq cigarette(1) with an arithmetic mean of 83 mBq cigarette(1). The annual committed effective doses were also calculated, based on the scenario that a smoker consumes 20 cigarettes a day. The average doses from Pb-210 and Po-210 inhalations were 229 and 6827 Sv y(1), respectively.

DOI： 10.1093/rpd/ncr364

Pressure dependence of X-rays produced by an LiTaO3 single crystal at low pressures

Katsumi Hanamoto, Atsushi Kawabe, Akihiro Sakoda, Takahiro Kataoka, Mari Okada, Kiyonori Yamaoka

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 669 66 - 69 2012.3

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The energy spectra of X-rays produced by an LiTaO3 single crystal have been measured at pressures of 5-50 Pa. The energy spectra showed that the amount of X-rays increased exponentially and the endpoint energy of the spectra increased linearly with the decrease of pressure at pressures of 10-25 Pa. A maximum endpoint energy of about 22 key was obtained using an LiTaO3 single crystal with 0.5 mm thickness at the pressure of 10 Pa. The maximum energy produced by the present experimental setup was estimated assuming that the LiTaO3 single crystal forms a parallel-plate capacitor. The estimated energy reasonably agreed with the energy obtained. The pressure dependence of the endpoint energy was discussed in relation to the breakdown potential at low pressures. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nima.2011.12.028

ラドン吸入がペットの健康改善に及ぼす効果に関する基礎的検討

片岡隆浩, 徳永力三, 迫田晃弘, 川辺睦, 花元克巳, 山岡聖典

Radioisotopes 61 ( 1 ) 3 - 10 2012.1

Comparative Study on the Inhibitory Effects of alpha-Tocopherol and Radon on Carbon Tetrachloride-Induced Renal Damage

Takahiro Kataoka, Keiko Yamato, Yuichi Nishiyama, Yuji Morii, Reo Etani, Yuji Takata, Katsumi Hanamoto, Atsuishi Kawabe, Akihiro Sakoda, Yuu Ishimori, Takehito Taguchi, Kiyonori Yamaoka

RENAL FAILURE 34 ( 9 ) 1181 - 1187 2012

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

Since the 2011 nuclear accident in Fukushima, the effects of low-dose irradiation, especially internal exposure, are at the forefront of everyone's attention. However, low-dose radiation induced various stimulating effects such as activation of antioxidative and immune functions. In this study, we attempted to evaluate the quantitative effects of the activation of antioxidative activities in kidney induced by radon inhalation on carbon tetrachloride (CCl4)-induced renal damage. Mice were subjected to intraperitoneal (i.p.) injection of CCl4 after inhaling approximately 1000 or 2000 Bq/m(3) radon for 24 h, or immediately after i.p. injection of alpha-tocopherol (100, 300, or 500 mg/kg bodyweight). In case of renal function, radon inhalation at a concentration of 2000 Bq/m(3) has the inhibitory effects similar to alpha-tocopherol treatment at a dose of 300-500 mg/kg bodyweight. The activities of superoxide dismutase and catalase in kidneys were significantly higher in mice exposed to radon as compared to mice treated with CCl4 alone. These findings suggest that radon inhalation has an antioxidative effect against CCl4-induced renal damage similar to the antioxidative effects of alpha-tocopherol due to induction of antioxidative functions.

DOI： 10.3109/0886022X.2012.717496

Basic Study on Positive Effects of Radon Inhalation on Pet's Health

Takahiro KATAOKA, Rikizo TOKUNAGA, Akihiro SAKODA, Atsushi KAWABE, Katsumi HANAMOTO, Kiyonori YAMAOKA

RADIOISOTOPES 61 ( 1 ) 1 - 8 2012

獣医療における診療従事者被ばくの現状と対策

川辺睦, 山田一孝, 岸本海織, 花元克巳, 山岡聖典

日本放射線技師会雑誌 58 ( 9 ) 849 - 849 2011.9

Studies on possibility for alleviation of lifestyle diseases by low-dose irradiation or radon inhalation. Reviewed

Kataoka T, Sakoda A, Yoshimoto M, Nakagawa S, Toyota T, Nishiyama Y, Yamato K, Ishimori Y, Kawabe A, Hanamoto K, Taguchi T, Yamaoka K

Radiation protection dosimetry 146 ( 1-3 ) 360 - 363 2011.7

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS

Our previous studies showed the possibility that activation of the antioxidative function alleviates various oxidative damages, which are related to lifestyle diseases. Results showed that, low-dose X-ray irradiation activated superoxide dismutase and inhibits oedema following ischaemia-reperfusion. To alleviate ischaemia-reperfusion injury with transplantation, the changes of the antioxidative function in liver graft using low-dose X-ray irradiation immediately after exenteration were examined. Results showed that liver grafts activate the antioxidative function as a result of irradiation. In addition, radon inhalation enhances the antioxidative function in some organs, and alleviates alcohol-induced oxidative damage of mouse liver. Moreover, in order to determine the most effective condition of radon inhalation, mice inhaled radon before or after carbon tetrachloride (CCl4) administration. Results showed that radon inhalation alleviates CCl4-induced hepatopathy, especially prior inhalation. It is highly possible that adequate activation of antioxidative functions induced by low-dose irradiation can contribute to preventing or reducing oxidative damages, which are related to lifestyle diseases.

DOI： 10.1093/rpd/ncr189

A comparative study on effect of continuous radon inhalation on several-time acute alcohol-induced oxidative damages of liver and brain in mouse

Takahiro Kataoka, Akihiro Sakoda, Masaaki Yoshimoto, Teruaki Toyota, Yuki Yamamoto, Yuu Ishimori, Katsumi Hanamoto, Atsushi Kawabe, Fumihiro Mitsunobu, Kiyonori Yamaoka

Radiation Safety Management 10 ( 1 ) 1 - 7 2011

Erratum to Differences of natural radioactivity and radon emanation fraction between constituent minerals of rock or soil [Appl. Radiat. Isot. 68, 6, (2010), 1180-1184] Reviewed

Akihiro Sakoda, Yuichi Nishiyama, Katsumi Hanamoto, Yuu Ishimori, Yuki Yamamoto, Takahiro Kataoka, Atsushi Kawabe, Kiyonori Yamaoka

Applied Radiation and Isotopes 68 ( 12 ) 2452 2010.12

Applicability and performance of an imaging plate at subzero temperatures Reviewed

Akihiro Sakoda, Yuu Ishimori, Katsumi Hanamoto, Atsushi Kawabe, Takahiro Kataoka, Tomohiro Nagamatsu, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 68 ( 10 ) 2013 - 2015 2010.10

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The performance of imaging plates (IPs) has not been studied at temperatures lower than 0 degrees C. In the present study, an IP was irradiated with gamma rays emitted from the mineral monazite at temperatures between -80 and 30 degrees C to determine its fundamental properties. The IP response as a function of irradiation time was found to be linear, suggesting that the IP works properly at low temperatures. Fading, an effect which should be considered at temperatures of more than 0 degrees C, was not observed at -30 and 80 degrees C. Furthermore, the fading-corrected PSL value of the IP irradiated at 80 degrees C was lower than at other temperatures (30.5 and -30 degrees C). This can be explained by thermostimulated luminescence (TSL). Since the only intensive TSL peak in the temperature range from -80 to 30 degrees C is present at about -43 degrees C, some of the electrons trapped at F centers recombine with holes through the process of TSL before the stored radiation image is read out at room temperature. This finding suggests that the apparent sensitivity of the IP is lower at -80 degrees C although it is similar to sensitivities between -30 and 30 degrees C. This low sensitivity should be corrected to perform quantitative measurements. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2010.03.020

Physiologically Based Pharmacokinetic Modeling of Inhaled Radon to Calculate Absorbed Doses in Mice, Rats, and Humans Reviewed

Akihiro Sakoda, Yuu Ishimori, Atsushi Kawabe, Takahiro Kataoka, Katsumi Hanamoto, Kiyonori Yamaoka

JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY 47 ( 8 ) 731 - 738 2010.8

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

This is the first report to provide radiation doses, arising from inhalation of radon itself, in mice and rats. To quantify absorbed doses to organs and tissues in mice, rats, and humans, we computed the behavior of inhaled radon in their bodies on the basis of a physiologically based pharmacokinetic (PBPK) model. It was assumed that radon dissolved in blood entering the gas exchange compartment is transported to any tissue by the blood circulation to be instantaneously distributed according to a tissue/blood partition coefficient. The calculated concentrations of radon in the adipose tissue and red bone marrow following its inhalation were much higher than those in the others, because of the higher partition coefficients. Compared with a previous experimental data for rats and model calculation for humans, the present calculation was proved to be valid. Absorbed dose rates to organs and tissues were estimated to be within the range of 0.04-1.4 nGy (Bq m(-3))(-1) day(-1) for all the species. Although the dose rates are not so high, it may be better to pay attention to the dose to the red bone marrow from the perspective of radiation protection. For more accurate dose assessment, it is necessary to update tissue/blood partition coefficients of radon that strongly govern the result of the PBPK modeling.

DOI： 10.1080/18811248.2010.9711649

First model of the effect of grain size on radon emanation Reviewed

Akihiro Sakoda, Katsumi Hanamoto, Yuu Ishimori, Takahiro Kataoka, Atsushi Kawabe, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 68 ( 6 ) 1169 - 1172 2010.6

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The present model represents an improvement on previous models of radon emanation from soil by incorporating soil grain size in addition to moisture. Monte Carlo simulation was employed in the calculation since it was difficult to mathematically express the radon emanation fraction for the present soil model. Grain size is one of the most important factors in describing the properties of soil. Grain size was demonstrated to affect the radon emanation fraction, depending on moisture content. Although the emanation fraction is generally considered to be proportional to grain size, the result of the model calculation suggested that the effect of grain size is not so simple. This study should serve as an initial step toward improving the modeling of this radon emanation. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2009.11.070

Differences of natural radioactivity and radon emanation fraction among constituent minerals of rock or soil Reviewed

Akihiro Sakoda, Yuichi Nishiyama, Katsumi Hanamoto, Yuu Ishimori, Yuki Yamamoto, Takahiro Kataoka, Atsushi Kawabe, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 68 ( 6 ) 1180 - 1184 2010.6

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

We examined differences in the radioactive characteristics among the main minerals forming granite materials. Using a non-toxic high-density agent, minerals were separated from rock (granite-gneiss) and soil (weathered granite) samples. The natural radioactivity ((238)U and (226)Ra) and radon emanation fraction of the minerals were then studied by gamma-ray spectrometry. The radon emanation fractions (27-43%) of the minerals from the soil were much higher than those (0.6-4.6%) of the rock minerals. Additionally, the emanation fractions differed greatly among the minerals separated from both the bulk rock and soil. These results were discussed in terms of the differences of surface area and radium distribution in the mineral grains. It was noticeable that a higher emanation fraction than expected for quartz was commonly observed in the rock and soil samples. We then estimated the contribution of each constituent mineral to the total radon exhalation from the bulk samples. The result depended not only on the radon emanation fraction, but also on the (226)Ra activity and the mineral content. Furthermore, using the obtained data, we also discussed the effect of grain size on radon emanation and why this has been reported to vary markedly in previous studies. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2009.12.036

Experimental and modeling studies of grain size and moisture content effects on radon emanation Reviewed

Akihiro Sakoda, Yuu Ishimori, Katsumi Hanamoto, Takahiro Kataoka, Atsushi Kawabe, Kiyonori Yamaoka

RADIATION MEASUREMENTS 45 ( 2 ) 204 - 210 2010.2

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Some models have already been developed to explain the effect of moisture content on the radon emanation fraction of soil. For this purpose, "microscopic" soil models, which are easy to deal with mathematically but cannot take grain size into consideration, have been designed. These previous models consist basically of two opposite grain surfaces and pores between the grains. In the present study, in order to study the effect of not only moisture content but also grain size, we present a simple modeling approach based on two "macroscopic" soil models: (1) a single-grain model and (2) a multiple-grain model. The latter model represents a configuration of spherical grains packed in a simple cubic structure. Based on these soil models and general assumptions, the radon emanation fraction was calculated as a function of grain size or moisture content by Monte Carlo simulation. The results for the multiple-grain model show that the radon emanation fraction is markedly increased with grain sizes ranging from 10 to 100 inn and reaches a constant value of 50% when moisture content is 0% and the radium is uniformly distributed on the grain surface. Moreover, a drastic increase is seen at smaller grain sizes with increasing moisture content. From these results, we concluded that the calculation of radon emanation depends greatly on the pore size between a Ra-bearing grain and a neighboring grain. The validity of the model was also evaluated by comparison to experimental data. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.radmeas.2010.01.010

Estimation of Occupational Radiation Exposure in Veterinary Practice Reviewed

KAWABE Atsushi, YAMADA Kazutaka, HANAMOTO Katsumi, SAKODA Akihiro, KATAOKA Takahiro, YAMAOKA Kiyonori

Journal of Animal Clinical Medicine 19 ( 4 ) 113 - 117 2010

Language：Japanese Publisher：Japanese Society of Clinical Veterinary Medicine

The purpose of this study was to estimate the effective dose of radiation to which veterinary staff were exposed during general radiographic procedures. The Ordinance for Enforcement of Veterinary Practice Act has published dose limits of occupational exposure in accordance with the International Commission on Radiological Protection. According to the recommendation, exposure of any radiation worker must be maintained beneath a certain dose limit, that is, the dose must not exceed 20 mSv per year for 5 consecutive years. But there is danger that single dosimetry under a lead apron might lead to underestimation of the dose that a radiation worker actually received. Calculation by single dosimetry is done as if the whole body was radiated uniformly, although protective shielding such as a lead apron covers the body widely. The Act requires double dosimetry to estimate the effective dose of radiation more exactly, and requires that a radiation worker should wear an additional dosimeter at the location at which he or she receives the highest deep-dose equivalent. Experimentally, using a double dosimitry model, we tested and calculated the effective dose for veterinary staff: it was 2.4 micro Sv per one radiograph. By extrapolation, it is estimated that the limit of 20 mSv per year will be exceeded when, for example, one veterinary nurse is engaged in holding an animal down on the stand to take one radiograph, more than 160 times per week, excluding exposure of the hands.

DOI： 10.11252/dobutsurinshoigaku.19.113

バドガスタイン産出岩石から分離した鉱石中の放射能特性

花元克巳, 迫田晃弘, 山本祐紀, 西山祐一, 石森有, 永松知洋, 山岡聖典

日本放射線影響学会大会講演要旨集 51回 151 - 151 2008.11

様々な単粒構造土壌モデルにおけるラドン散逸能の算出

迫田晃弘, 花元克巳, 石森有, 山岡聖典

日本放射線影響学会大会講演要旨集 51回 151 - 151 2008.11

Radioactivity and radon emanation fraction of the granites sampled at Misasa and Badgastein

Akihiro Sakoda, Katsumi Hanamoto, Yuu Ishimori, Tomohiro Nagamatsu, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 66 ( 5 ) 648 - 652 2008.5

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The chemical composition was analyzed and the radioactivity, radon exhalation rate and emanation fraction were measured to investigate the characteristics of the granites sampled at Misasa and Badgastein, world famous for radon therapy. The Misasa granite was probably composed of quartz, albite and microcline. The Badgastein granite was probably composed of quartz and muscovite. The radon exhalation rates and emanation fractions of the Misasa granite were much higher than those of the Badgastein granite, regardless of the (226)Ra activity concentrations. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2007.11.015

小型MRI装置の作製エコー信号のフィッティングによる再構成画像の鮮鋭化

花元克巳, 加藤博和, 澁谷光一, 川崎祥二, 黒田昌宏, 金澤右, 岸幹二, 柳文修, 本多康聡, 大野誠一郎, 門久繁文, 高橋則雄, 青木雅昭

Radiation Medicine 26 ( Suppl.I ) 59 - 59 2008.4

MRI装置の作製

加藤博和, 花元克巳, 山本尚武, 黒田昌宏, 金澤右, 本多康聡, 柳文修, 高橋則雄, 岸幹二, 大塚裕太, 井上皓介, 真鍋英朗, 宮武匡義, 青木雅昭

Radiation Medicine 26 ( Suppl.I ) 58 - 58 2008.4

Effects of some physical conditions on leaching rate of radon from radioactive minerals originating from some hot springs

Akihiro Sakoda, Katsumi Hanamoto, Yuu Ishimori, Tomohiro Nagamatsu, Kiyonori Yamaoka

RADIATION MEASUREMENTS 43 ( 1 ) 106 - 110 2008.1

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

In order to determine the best physical conditions for leaching more radon from minerals into water, we measured the leaching rate of radon from radioactive minerals under the conditions of some different grain sizes and water temperatures. Water temperature affected the leaching rate of radon although the grain size did not significantly affect it. Furthermore, we proposed ultrasonic irradiation to the mixture of a mineral and water as the method of leaching more radon. Ultrasonic irradiation was efficient to leach more radon from the mineral soaked in water because of ultrasonic cavitation. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.radmeas.2007.07.009

Basic Study on Activation of Antioxidation Function in Some Organs of Mice by Radon Inhalation Using New Radon Exposure Device

Shinya NAKAGAWA, Takahiro KATAOKA, Akihiro SAKODA, Yuu ISHIMORI, Katsumi HANAMOTO, Kiyonori YAMAOKA

RADIOISOTOPES 57 ( 4 ) 241 - 245 2008

Methodological Approach for Assessment of the Radioactivity Level in Dry Solid Waste

Tomohiro Nagamatsu, Akihiro Sakoda, Katsumi Hanamoto, Ikuo Kinno, Tadashi Hanafusa, Kiyonori Yamaoka, Toshiro Ono

Radiation Safety Management 7 ( 1 ) 6 - 10 2008

天然放射性鉱石からの222Rn散逸率に影響を及ぼす環境諸因子の検討

花元克巳, 迫田晃弘, 永松知洋, 石森有, 山岡聖典

日本放射線影響学会大会講演要旨集 50回 120 - 120 2007.11

γ線スペクトロメトリによる天然放射性鉱石からの222Rn散逸率の測定

迫田晃弘, 花元克巳, 永松知洋, 石森有, 山岡聖典

日本放射線影響学会大会講演要旨集 50回 121 - 121 2007.11

小型MRI装置の作製矩形ファントムの画像再構成

加藤博和, 花元克巳, 澁谷光一, 川崎祥二, 黒田昌宏, 金澤右, 柳文修, 本多康聡, 岸幹二, 高橋則雄, 綾野成記, 芝潤, 金澤圭剛

Radiation Medicine 25 ( Suppl.I ) 92 - 92 2007.4

位相エンコーディング方向に現れる低信号アーチファクトの解析

花元克巳, 加藤博和, 澁谷光一, 川崎祥二, 黒田昌宏, 金澤右, 大野誠一郎, 門久繁文

Radiation Medicine 25 ( Suppl.I ) 92 - 92 2007.4

A comparative study on the characteristics of radioactivities and negative air ions originating from the minerals in some radon hot springs

Akihiro Sakoda, Katsumi Hanamoto, Naoto Haruki, Tomohiro Nagamatsu, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 65 ( 1 ) 50 - 56 2007.1

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

To elucidate the characteristics of some radon hot springs, we simulated a hot spring by soaking the rocks for the radon therapy in water and measured the concentrations of radon and negative air ions in various conditions. In the results, the individual rock structure could contribute to radon leaching because the radon leaching rates were independent of the grain sizes. More negative air ions were generated by the wet rocks than by the dry rocks. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2006.07.015

天然放射性鉱石から水中への放射性核種の浸出率に及ぼす環境諸因子の比較検討

迫田晃弘, 花元克巳, 川辺睦, 永松知洋, 山岡聖典

日本放射線影響学会大会講演要旨集 49回 133 - 133 2006.9

Energy Response of an Optically Stimulated Luminescence Dosemeter to Low Energy Continuous X-rays(Part 2:Japanese Papers)

KAWABE Atsushi, SHIBUYA Koichi, HANAMOTO Katsumi, KOBAYASHI Ikuo, TAKEDA Yoshihiro

Japanese Journal of Health Physics 41 ( 4 ) 249 - 255 2006

Language：Japanese Publisher：Japan Health Physics Society

To investigate the energy response of an optically stimulated luminescence dosemeter (OSLD) with low energy photons, OSLDs were irradiated by low energy continuous X-rays which have various energy distributions. The effective energy of the X-ray was in the range 10.0-14.5keV, and homogeneity factor was in the range 0.5-0.9. As a result, at 11.0keV, the OSLD-to-ionization chamber ratio was maintained at almost a constant level from 1.03 at a 0.5 to 1.08 at a 0.7 homogeneity factor. However, the OSLD tended to overestimate measured value with an increase of effective energy. Probably, this error can be eliminated by calculating an appropriate correction factor.

DOI： 10.5453/jhps.41.249

Other Link： https://jlc.jst.go.jp/DN/JALC/00289894802?from=CiNii

人工トロン温泉に由来する放射能とマイナスイオンの諸特性に関する検討

花元克巳, 迫田晃弘, 篠塚龍, 山岡聖典

日本放射線影響学会大会講演要旨集 48回 134 - 134 2005.11

バドガスタイン天然鉱石に由来する放射能と負(マイナス)イオンの諸特性に関する検討

迫田晃弘, 花元克巳, 川辺睦, 山岡聖典

日本放射線影響学会大会講演要旨集 48回 133 - 133 2005.11

Composition of MRI phantom equivalent to human tissues

H Kato, M Kuroda, K Yoshimura, A Yoshida, K Hanamoto, S Kawasaki, K Shibuya, S Kanazawa

MEDICAL PHYSICS 32 ( 10 ) 3199 - 3208 2005.10

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS

We previously developed two new MRI phantoms (called the CAG phantom and the CAGN phantom), with T1 and T2 relaxation times equivalent to those of any human tissue at 1.5 T. The conductivity of the CAGN phantom is equivalent to that of most types of human tissue in the frequency range of 1 to 130 MHz. In this paper, the relaxation times of human tissues are summarized, and the composition of the corresponding phantoms are provided in table form. The ingredients of these phantoms are carrageenan as the gelling agent, GdCl3 as a T1 modifier, a-arose as a T2 modifier, NaCl (CAGN phantom only) as a conductivity modifier, NaN3 as an antiseptic, and distilled water. The phantoms have T1 values of 202-1904 ms and T2 values of 38-423 ms when the concentrations of GdCl3 and agarose are varied from 0-140 mu mol/kg, and 0%-1.6%, respectively, and the CAGN phantom has a conductivity of 0.27-1.26 S/m when the NaCl concentration is varied from 0%-0.7%. These phantoms have sufficient strength to replicate a torso without the use of reinforcing agents, and can be cut by a knife into any shape. We anticipate the CAGN phantom to be highly useful and practical for MRI and hyperthermia-related research. (9) 2005 American Association of Physicists in Medicine.

DOI： 10.1118/1.2047807

Development of a new hybrid gel phantom using carrageenan and gellan gum for visualizing three-dimensional temperature distribution during hyperthermia and radiofrequency ablation

M Kuroda, H Kato, K Hanamoto, K Shimamura, T Uchida, Y Wang, S Akaki, JI Asaumi, K Himei, M Takemoto, S Kanazawa, K Shibuya, S Kawasaki, Y Hiraki

INTERNATIONAL JOURNAL OF ONCOLOGY 27 ( 1 ) 175 - 184 2005.7

Language：English Publishing type：Research paper (scientific journal) Publisher：SPANDIDOS PUBL LTD

We developed a new hybrid gel phantom using carrageenan and gellan gum for the purpose of visualizing three-dimensional temperature distribution. The phantom, which contains carrageenan, gellan gum, non-ionic surface active agent, potassium chloride, n-butanol, sodium azide, and water, shows good transparency at room temperature, and has the advantage that the heated region becomes white and opaque due to segregation of the surface active agent. Carrageenan and gellan gum were added to improve the transparency and fragility of the hybrid gel. Potassium chloride was used to adjust the electrical conductivity of the gel to a range of 5-130 MHz, so that it would be equivalent to that of muscle tissue for each frequency used by electromagnetic heating devices. N-butanol was used to adjust the clouding temperature to a range between 45 and 55 degrees C. In the present study we clarified the important properties of the new phantom, and developed formulae for easy determination of the amounts of ingredients necessary for the desired clouding temperature and electric conductivity. The characteristics of this phantom are: a) a solid form to avoid convection by heat conduction; b) sufficient strength without fragility to form a torso without the use of a reinforcing agent; c) high transparency at room temperature and visualization of the heating area as a white turbidity; d) time-lapse and accurate visualization of the changing temperature area without thermal hysteresis; e) electrical properties similar to those of human tissues; f) ease of production; and g) low cost and good safety. This phantom might assist oncologists in their routine checking and study of the performance of electromagnetic heating devices for hyperthermia and radiofrequency ablation.

小型MRI装置用シーケンシャルパルスジェネレータの開発

花元克己, 加藤博和, 帆足正勝, 青山良宏, 西健二, 溝渕真一, 大胡文彦, 坂井千尋, 田中雅大, 馬場園喬, 黒田昌宏, 金澤右

日本医学放射線学会雑誌 65 ( 2 ) 154 - 154 2005.4

MnSOD遺伝子導入に伴うplating efficiencyの変化

黒田昌宏, 小松めぐみ, 王雅棣, 加藤博和, 花元克巳, 武本充広, 姫井健吾, 山本泰宏, 平木祥夫, 金澤右

日本医学放射線学会雑誌 65 ( 2 ) 161 - 161 2005.4

p53遺伝子,MnSOD遺伝子導入に伴う細胞死の検討

王雅棣, 黒田昌宏, 小松めぐみ, 加藤博和, 花元克己, 姫井健吾, 武本充広, 山本泰宏, 平木祥夫, 金澤右

日本医学放射線学会雑誌 65 ( 2 ) 161 - 161 2005.4

小型MRI装置用RFコイルの作製

加藤博和, 花元克巳, 青山良宏, 帆足正勝, 大胡文彦, 黒田昌宏, 金澤右, 溝渕真一, 西健二, 坂井千尋, 田中雅大, 馬場園喬

日本医学放射線学会雑誌 65 ( 2 ) 155 - 155 2005.4

The elevation of p53 protein level and SOD activity in the resident blood of the Misasa radon hot spring district

K Yamaoka, F Mitsunobu, S Kojima, M Shibakura, T Kataoka, K Hanamoto, Y Tanizaki

JOURNAL OF RADIATION RESEARCH 46 ( 1 ) 21 - 24 2005.3

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN RADIATION RESEARCH SOC

To clarify the mechanism by which radon hot springs prevent cancer or not, in this study, blood was collected from residents in the Misasa hot spring district and in a control district. The level of a representative cancer-suppressive gene, p53, and the activity of a representative antioxidant enzyme, superoxide dismutase (SOD), were analyzed as indices. The level of serum p53 protein in the males in the Misasa hot spring district was found to be 2-fold higher than that in the control district, which is a significant difference. In the females in the Misasa hot spring district, SOD activity was approximately 15% higher than that in the control district, which is also statistically significant, and exceeded the reference range of SOD activity despite advanced age. These results suggested that routine exposure of the residents in the Misasa hot spring district to radon at a concentration about 3 times higher than the national mean induces trace active oxygen in vivo, potentiating products of cancer- suppressive gene and antioxidant function. As the p53 protein level was high in the residents in the Misasa hot spring district, apoptosis of cancer cells may readily occur.

DOI： 10.1269/jrr.46.21

A comparative study on radioactive characteristics of the minerals for radon therapy

K Hanamoto, K Yamaoka

RADIATION MEASUREMENTS 39 ( 2 ) 157 - 160 2005.2

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

To elucidate the mechanism of the radon therapy, we analyzed the radioactive characteristics of the minerals in the famous regions for the radon therapy. Using a high-purity germanium detector, we measured the sludge at the hot bathroom with a high concentration of radon at Misasa Medical Center of Okayama University Medical School, the hokutolite, which was the same kind of mineral at Tamagawa Hot Spring in Japan, and the mineral at the gallery of Badgastein in Austria, which are celebrated regions for the radon therapy. As a result, the ratios of the uranium series to the thorium series for the sludge of Misasa, the hokutolite, and the mineral of Badgastein were 22, 50, and 0.94, respectively. The sludge of Misasa and the hokutolite mainly included the radioelements of the uranium series, while the mineral of Badgastein included the radioelements of both series with almost the same ratio. The ratio of the mineral of Badgastein is similar to that of background (1.1). Furthermore, two kinds of minerals, which are commercially available for radon therapy, were measured using the same detector. The ratios for the two minerals were 0.26 and 0.20, namely, the two minerals included larger radioelements of the thorium series than those of the uranium series. (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.radmeas.2004.04.008

MRIファントムの開発

加藤博和, 花元克巳, 川崎祥二, 澁谷光一, 黒田昌宏, 吉村孝一, 吉田敦史, 津野田雅敏, 武本充広, 金澤右, 平木祥夫

日本医学放射線学会雑誌 65 ( 1 ) 77 - 78 2005.1

Study on Radioactivity and Negative Ion Originated from a Thoron Artificial Hot Spring

Akihiro SAKODA, Takahiro KATAOKA, Katsumi HANAMOTO, Kiyonori YAMAOKA

RADIOISOTOPES 54 ( 9 ) 375 - 383 2005

Simplification of analysis for comparison of radioactive characteristics and its application to some minerals for radon therapy Reviewed

K Hanamoto, K Yamaoka

HIGH LEVELS OF NATURAL RADIATION AND RADON AREAS: RADIATION DOSE AND HEALTH EFFECTS 1276 253 - 255 2005

Language：English Publishing type：Research paper (international conference proceedings) Publisher：ELSEVIER SCIENCE BV

To simplify the analysis of the radioactive characteristics of the minerals for the radon therapy, we developed a simple method to calculate the ratio of the uranium series to the thorium series (U/Th) without using activity. The ratios calculated by this method agreed well with the ratios calculated using the activity. We applied this method to some minerals for the radon therapy. As a result, the U/Th's for the sludge of Misasa, the hokutolite, the mineral of Badgastein, and the two kinds of commercially available minerals were 22, 50, 0.94, 0.26, and 0.20, respectively. (c) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ics.2004.09.029

Effects of radon and thennal therapy on osteoarthritis Reviewed

K Yamaoka, F Mitsunobu, K Hanamoto, T Kataoka, Y Tanizaki

HIGH LEVELS OF NATURAL RADIATION AND RADON AREAS: RADIATION DOSE AND HEALTH EFFECTS 1276 249 - 250 2005

Language：English Publishing type：Research paper (international conference proceedings) Publisher：ELSEVIER SCIENCE BV

We examined the temporal changes in antioxidants, immune-, vasoactive- and pain-associated substances in human blood by therapy to elucidate the mechanism of osteoarthritis in which radon therapy is used as a treatment. Results showed that radon inhalation enhanced the antioxidation and immune function, and that the changes in vasoactive and pain-associated substances indicate increases in tissue perfusion brought about by radon therapy. (c) 2004 Published by Elsevier B.V.

DOI： 10.1016/j.ics.2004.12.013

Development of a phantom compatible for MRI and hyperthermia using carrageenan gel-relationship between T-1 and T-2 values and NaCl concentration

A Yoshida, H Kato, M Kuroda, K Hanamoto, K Yoshimura, K Shibuya, S Kawasaki, M Tsunoda, S Kanazawa, Y Hiraki

INTERNATIONAL JOURNAL OF HYPERTHERMIA 20 ( 8 ) 803 - 814 2004.12

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

The authors developed a phantom, designated as the CAGN phantom, compatible for MRI and hyperthermia that is useful in the fundamental studies of non-invasive MR thermometry. The ingredients of this phantom are carrageenan, GdCl3 as a T-1 modifier, agarose as a T-2 modifier, NaCl as a conductivity modifier, NaN3 as an antiseptic and distilled water. Another phantom that was developed, the CAG phantom, has relaxation times that are adjustable to those of any human tissue. To use this phantom for electromagnetic heating, NaCl was added to change the conductivity of the phantom and clarified the relationship between the conductivity and NaCl concentration. This study examined the relationship between relaxation times and NaCl concentration of the CAGN phantom. The results showed that both T-1 and T-2 values were affected by NaCl and the experimental results led to the empirical formulae expressing the relationship between the relaxation rates (1/T-1, 1/T-2) and the concentrations of GdCl3, agarose and NaCl. The appropriate concentrations of T-1 and T-2 modifiers were calculated from these empirical formulae when making a specified phantom that has the required relaxation times and NaCl concentration.

DOI： 10.1080/0265673042000199268

MRIにおいて位相方向に出現するアーチファクト

大野誠一郎, 小水満, 花元克巳, 加藤博和, 黒田昌宏, 金澤右

日本放射線技術学会雑誌 60 ( 9 ) 1261 - 1261 2004.9

磁化を指標にしたMRIによる温度測定

花元克巳, 加藤博和, 黒田昌宏, 澁谷光一, 川崎祥二, 金澤右

日本ハイパーサーミア学会誌 21 ( Suppl. ) 60 - 60 2004.9

Development of a phantom compatible for MRI and hyperthermia using carrageenan gel - relationship between dielectric properties and NaCl concentration Reviewed

H Kato, K Yoshimura, M Kuroda, A Yoshida, K Hanamoto, S Kawasaki, K Shibuya, Y Yamamoto, M Tsunoda, M Takemoto, Y Hiraki

INTERNATIONAL JOURNAL OF HYPERTHERMIA 20 ( 5 ) 529 - 538 2004.8

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

A phantom has previously been developed containing carrageenan, agarose and gadolmium chloride (called CAG phantom) for MRI with 1.5T. T-1 and T-2 relaxation times of this phantom are independently changeable by varying concentrations of relaxation-time modifiers to simulate relaxation times of the various types of human tissues. The CAG phantom has a T, value of 202-1904 ms and a T-2 value of 38-423 ins, when the GdCl3 concentration is varied from 0-140 mumol/kg and the agarose concentration is varied from 0-1.6%. A new phantom has now been developed (called CAGN phantom), made by adding an electric conductive agent, NaCl, to the CAG phantom for use in the areas of MRI and hyperthermia research. Dielectric properties of the CAGN phantom were measured and the results of experiments were expressed by the Cole-Cole equation in the frequency range of 5-130 MHz. The relationship between the conductivity of the CAGN phantom and the concentration of NaCl was expressed by a linear function in the frequency range of 1-130 MHz. The linear function involves a parameter of frequency and, when the frequency is 10 MHz, the conductivity of the CAGN phantom can be changed from 0.27-1.26 Sm-1 by increasing the NaCl concentration from 0-0.7%. The CAGN phantom developed can be employed in basic experiments for non-invasive temperature measurement using MRI and as a loading phantom for MRI with up to 3 T.

DOI： 10.1080/0265673042000199277

MRIエコー信号のサンプリング時間測定と画像再構成

加藤博和, 花元克巳, 澁谷光一, 川崎祥二, 黒田昌宏, 吉村孝一, 吉田敦史, 津野田雅敏, 平木祥夫, 小山矩

日本医学放射線学会雑誌 64 ( 5 ) 339 - 339 2004.7

Biochemical comparison between radon effects and thermal effects on humans in radon hot spring therapy

K Yamaoka, F Mitsunobu, K Hanamoto, K Shibuya, S Mori, Y Tanizaki, K Sugita

JOURNAL OF RADIATION RESEARCH 45 ( 1 ) 83 - 88 2004.3

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN RADIATION RESEARCH SOC

The radioactive and thermal effects of radon hot spring were biochemically compared under a sauna room or hot spring conditions with a similar chemical component, using the parameters that are closely involved in the clinic for radon therapy. The results showed that the radon and thermal therapy enhanced the antioxidation functions, such as the activities of superoxide dismutase (SOD) and catalase, which inhibit lipid peroxidation and total cholesterol produced in the body. Moreover the therapy enhanced concanavalin A (ConA)-induced mitogen response and increased the percentage of CD4 positive cells, which is the marker of helper T cells, and decreased the percentage of CD8 positive cells, which is the common marker of killer T cells and suppressor T cells, in the white blood cell differentiation antigen (CD8/CD4) assay. Furthermore, the therapy increased the levels of a atrial natriuretic polypeptide (alphaANP), beta endorphin, adrenocorticotropic hormone (ACTH), insulin and glucose-6-phosphate dehydrogenase (G-6-PDH), and it decreased the vasopression level. The results were on the whole larger in the radon group than in the thermal group. The findings suggest that radon therapy contributes more to the prevention of life-style-related diseases related to peroxidation reactions and immune suppression than to thermal therapy. Moreover, these indicate what may be a part of the mechanism for the alleviation of hypertension, osteoarthritis (pain), and diabetes mellitus brought about more by radon therapy than by thermal therapy.

DOI： 10.1269/jrr.45.83

Inhibitory effects of prior low-dose X-ray irradiation on carbon tetrachloride-induced hepatopathy in acatalasemic mice

K Yamaoka, T Kataoka, T Nomura, T Taguchi, DH Wang, S Mori, K Hanamoto, S Kira

JOURNAL OF RADIATION RESEARCH 45 ( 1 ) 89 - 95 2004.3

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN RADIATION RESEARCH SOC

The catalase activities in blood and organs of the acatalasemic (C3H/AnLCs(b)Cs(b)) mouse of C3H strain are lower than those of the normal (C3H/AnLCs(a)Cs(a)) mouse. We examined the effects of prior low-dose (0.5 Gy) X-ray irradiation, which reduced the oxidative damage under carbon tetrachloride-induced hepatopathy in the acatalasemic or normal mice. The acatalasemic mice showed a significantly lower catalase activity and a significantly higher glutathione peroxidase activity compared with those in the normal mice. Moreover, low-dose irradiation increased the catalase activity in the acatalasemic mouse liver to a level similar to that of the normal mouse liver. Pathological examinations and analyses of blood glutamic oxaloacetic and glutamic pyruvic transaminase activity and lipid peroxide levels showed that carbon tetrachloride induced hepatopathy was inhibited by low-dose irradiation. These findings may indicate that the free radical reaction induced by the lack of catalase and the administration of carbon tetrachloride is more properly neutralized by high glutathione peroxidase activity and low-dose irradiation in the acatalasemic mouse liver.

DOI： 10.1269/jrr.45.89

MRIにおけるサンプリング時間の測定と画像の再構成

加藤博和, 花元克巳, 川崎祥二, 澁谷光一, 黒田昌宏, 小山矩

岡山大学医学部保健学科紀要 14 ( 2 ) 121 - 128 2004.3

Language：Japanese Publisher：岡山大学医学部保健学科

MRはX線のように形態画像を表示できる以外に,機能画像,代謝画像,術中画像を表示できることから,重要な撮像モダリティーであるが,成書にはその画像再構成法の具体的な記述はなされていない.そこで,ファントムを用いて具体的に画像を再構成することを試みた.まず矩形ファントムを用いてサンプリング時間の測定を行った.次にMRI MULTI-TEST PHANTOMをスキャンすることによりファントムのエコー信号を採取した.このエコー信号を矩形ファントムで求めたサンプリング時間ごとにサンプリングすることによりk-spaceを得た.このk-spaceから逆フーリエ変換を行うことにより画像の再構成を行った.得られた画像とMRI装置に表示された画像の比較を行い,画像が再現されていることを確認した

Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2004&ichushi_jid=J03360&link_issn=&doc_id=20040610190002&doc_link_id=http%3A%2F%2Fousar.lib.okayama-u.ac.jp%2F15198&url=http%3A%2F%2Fousar.lib.okayama-u.ac.jp%2F15198&type=%89%AA%8ER%91%E5%8Aw%81F%89%AA%8ER%91%E5%8Aw%8Aw%8Fp%90%AC%89%CA%83%8A%83%7C%83W%83g%83%8A&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F80034_3.gif

Study on biologic effects of radon and thermal therapy on osteoarthritis

K Yamaoka, F Mitsunobu, K Hanamoto, S Mori, Y Tanizaki, K Sugita

JOURNAL OF PAIN 5 ( 1 ) 20 - 25 2004.2

Language：English Publishing type：Research paper (scientific journal) Publisher：CHURCHILL LIVINGSTONE

Radon therapy uses radon (Rn-222) gas, which mainly emits alpha-rays and induces a small amount of active oxygen in the body. We first examined the temporal changes in antioxidants, immune, vasoactive, and pain-associated substances in human blood by therapy to elucidate the mechanism of osteoarthritis in which radon therapy is used as a treatment. Results showed that radon inhalation enhanced the antioxidation and immune function, and the findings suggest that radon therapy contributes to the prevention of osteoarthritis related to peroxidation reactions and immune depression. Moreover, the changes in vasoactive and pain-associated substances indicated increases in tissue perfusion brought about by radon therapy, suggesting that radon inhalation plays a role in alleviating pain.
Perspective: The findings suggest that an appropriate amount of active oxygen is produced in the body after radon inhalation, and this contributes to the alleviation of the symptoms of active oxygen diseases such as osteoarthritis. (C) 2004 by the American Pain Society.

DOI： 10.1016/j.jpain.2003.09.005

Using Physiological Indices to Consider the Effects of Negative Air Ions on the Human Body.

白井喜代子, 山岡聖典, 花元克巳, 山本尚武

Journal of International Society of Life Information Science 22 ( 1 ) 2004

誘電型加温電極を用いた組織内または腔内加温のSARシミュレーション(SAR Simulation of Interstitial or Intracavitary Hyperthermia with One or Two External Flat Electrodes for Current Field Heating)

花元克巳, 加藤博和, 黒田昌宏, 澁谷光一, 川崎祥二, 池田裕子, 金澤右

日本ハイパーサーミア学会誌 20 ( 4 ) 241 - 247 2004

Language：English Publisher：(一社)日本ハイパーサーミア学会

組織内加温や腔内加温は一般に内部電極と外部電極の2電極で行われる.しかしながら,一対の平面外部電極の間に内部電極を留置する方法も行なわれている.この2つの加温方法の発熱分布を比較するために,今回,内部電極に1個と外部に誘電型加温電極を2個使用し,合計3電極でSARシミュレーションを行った.その結果,3電極の場合と2電極の場合を比較すると,3電極法では加熱方向を制御でき,熱放散の少ない加温ができることが示唆された

DOI： 10.3191/thermalmedicine.20.241

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22 教育・研究用小型MRIの開発 : RFコイルの設計と作製(MR検査装置)(一般研究発表)(第32回秋季学術大会)

大胡文彦, 門久繁文, 坂井千尋, 青山良宏, 帆足正勝, 加藤博和, 花元克己

日本放射線技術学会雑誌 60 ( 9 ) 1196 - 1196 2004

23 教育・研究用小型MRI装置の開発 : 傾斜磁場コイルの設計と作製(MR検査装置)(一般研究発表)(第32回秋季学術大会)

青山良宏, 帆足正勝, 加藤博和, 溝渕真一, 田中雅大, 馬場園喬, 花元克巳

日本放射線技術学会雑誌 60 ( 9 ) 1196 - 1197 2004

24 教育・研究用小型MRI装置の開発 : シーケンシャルパルスの生成(MR検査装置)(一般研究発表)(第32回秋季学術大会)

帆足正勝, 青山良宏, 加藤博和, 西健二, 大胡文彦, 花元克巳

日本放射線技術学会雑誌 60 ( 9 ) 1197 - 1197 2004

Development of a tissue-equivalent MRI phantom using carrageenan gel

K Yoshimura, H Kato, M Kuroda, A Yoshida, K Hanamoto, A Tanaka, M Tsunoda, S Kanazawa, K Shibuya, S Kawasaki, Y Hiraki

MAGNETIC RESONANCE IN MEDICINE 50 ( 5 ) 1011 - 1017 2003.11

Language：English Publishing type：Research paper (scientific journal) Publisher：JOHN WILEY & SONS INC

A new tissue-equivalent MRI phantom based on carrageenan gel was developed. Carrageenan gel is an ideal solidifying agent for making large, strong phantoms in a wide variety of shapes. GdCl3 was added as a T-1 modifier and agarose as a T-2 modifier. The relaxation times of a very large number of samples were estimated using 1.5-T clinical MRI equipment. The developed phantom was found to have a T-1 value of 202-1904 ms and a T-2 value of 38-423 ms when the GdCl3 concentration was varied from 0-140 mumol/kg and the agarose concentration was varied from 0-1.6% in a carrageenan concentration that was fixed at 3%. The range of measured relaxation times covered those of all types of human tissue. Empirical formulas linking the relaxation time with the concentration of the modifier were established to enable the accurate and easy calculation of the modifier concentration needed to achieve the required relaxation times. This enables the creation of a phantom having an arbitrary combination of T-1 and T-2 values and which is capable of retaining its shape. Magn Reson Med 50:1011-1017, 2003. (C) 2003 Wiley-Liss, Inc.

DOI： 10.1002/mrm.10619

誘電型加温電極を組み合わせた組織内加温のSAR分布シミュレーション

花元克巳, 加藤博和, 澁谷光一, 川崎祥二, 黒田昌宏, 平木祥夫

日本ハイパーサーミア学会誌 19 ( Suppl. ) 109 - 109 2003.9

MRI特性および電気的特性が人体と等価なファントムの開発成分濃度とMRIおよび電気的特性の関係

加藤博和, 黒田昌宏, 吉村孝一, 吉田敦史, 花元克巳, 川崎祥二, 澁谷光一, 津野田雅敏, 武本充広, 平木祥夫

日本ハイパーサーミア学会誌 19 ( Suppl. ) 149 - 149 2003.9

プロテインキナーゼ阻害剤,H89は温熱耐性発現を促進する

澁谷光一, 川崎祥二, 加藤博和, 花元克巳, 黒田昌宏, 浅海淳一, 平木祥夫

日本ハイパーサーミア学会誌 19 ( Suppl. ) 135 - 135 2003.9

カラギーナンゲルを用いた人体組織等価MRIファントムの開発 NaClの緩和時間に及ぼす効果の検討

吉田敦史, 加藤博和, 花元克巳, 黒田昌宏, 吉村孝一, 平木祥夫

日本ハイパーサーミア学会誌 19 ( Suppl. ) 148 - 148 2003.9

Elevation of antioxidant enzymes in the clinical effects of radon and thermal therapy for bronchial asthma

F Mitsunobu, K Yamaoka, K Hanamoto, S Kojima, Y Hosaki, K Ashida, K Sugita, Y Tanizaki

JOURNAL OF RADIATION RESEARCH 44 ( 2 ) 95 - 99 2003.6

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN RADIATION RESEARCH SOC

An increased systemic production of oxygen-free radicals by activated inflammatory cells is thought to be involved in the pathophysiology of asthma. The aim of this study is to evaluate the clinical effects of radon and thermal therapy on asthma in relation to antioxidant enzymes and lipid peroxide. Radon and thermal therapy were performed once a week. All subjects went to a hot bathroom with a high concentration of radon, and nasal inhalation of vapor from a hot spring was performed for 40 min once a day under conditions of high humidity. The room temperature was 48degreesC; the room radon concentration was 2,080 Bq/m(3). Blood samples were collected at 2 h, 14, and 28 days after the first therapy. A blood sample also was collected before the first therapy (at body temperature and background radon level) to be used as the control. The forced expiratory volume in one second (%FEV1) was significantly increased 28 days after the first therapy. Oil day 28, the catalase (CAT) activity was significantly increased in comparison with the control. The superoxide dismutase (SOD) activity was significantly increased compared to the control after first inhalation. On days 14 and 28, the lipid peroxide level was significantly decreased in comparison with the control. In conclusion, the present pilot study has shown that radon and thermal therapy improved the pulmonary function of asthmatics by increasing the reduced activities of antioxidant enzymes.

DOI： 10.1269/jrr.44.95

MRIにおける画像の再構成

加藤博和, 花元克巳, 黒田昌宏, 澁谷光一, 川崎祥二

岡山大学医学部保健学科紀要 13 ( 2 ) 77 - 82 2003.3

Protein kinaseの阻害剤であるH89はBHK21細胞とtsAF8細胞の温熱耐性の発現を促進する(H89, a Protein Kinase Inhibitor, Promotes the Development of Thermotolerance in BHK21 and tsAF8 Cells)

澁谷光一, 小畑文香, 上江洲美緒, 小林貴子, 松下利, 川崎祥二, 花元克巳, 加藤博和, 黒田昌宏, 浅海淳一, 平木祥夫

日本ハイパーサーミア学会誌 19 ( 4 ) 187 - 194 2003

Language：English Publisher：(一社)日本ハイパーサーミア学会

BHK21細胞とtsAF8細胞を用いてprotein kinaseの阻害剤であるCalphostin CとH89の,温熱耐性の発現に及ぼす効果を検討した.その結果,いずれの細胞においてもCalphostin Cによって温熱耐性の発現が阻害された.H89では0.05μMの濃度では温熱耐性の発現が阻害されたが,2.5μMでは逆に発現が促進された.Calphostin CはPKCを特異的に阻害し,H89は主にPKAを阻害するが濃度が高くなるとPKGも阻害する.温熱耐性の発現はPKCとPKAにより阻害されるが,PKGによって促進されることが示唆された

DOI： 10.3191/thermalmedicine.19.187

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三朝ラドン温泉適応症の機構に関する検討ラドン高濃度熱気浴反復治療による気管支喘息の改善の機構

光延文裕, 山岡聖典, 御舩尚志, 小島周二, 花元克巳, 杉田勝彦, 谷崎勝朗

日本放射線影響学会大会講演要旨集 45回 113 - 113 2002.9

吸入ラドンの体内動態に関する検討実験方法の確立に向けての試み

花元克巳, 光延文裕, 澁谷光一, 永松知洋, 汪達紘, 吉良尚平, 山岡聖典

日本放射線影響学会大会講演要旨集 45回 112 - 112 2002.9

三朝ラドン温泉適応症の機構に関する検討ラドン高濃度熱気浴反復治療による変形性関節症の改善の機構

山岡聖典, 光延文裕, 御舩尚志, 小島周二, 渋谷光一, 花元克巳, 谷崎勝朗, 杉田勝彦

日本放射線影響学会大会講演要旨集 45回 112 - 112 2002.9

Irradiation effect of synchrotron radiation on crystallization of thin amorphous WO3 film

Y Kimura, K Hanamoto, Y Nakayama, C Kaito

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 194 ( 2 ) 187 - 192 2002.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

In order to elucidate the effect of synchrotron radiation (SR) irradiation on crystal growth, crystallization of WO3 films has been performed in vacuum under SR irradiation. The main results were compared with the results of heat treatment of the same film. Upon SR irradiation for 80 s using a toroidal mirror, a catastrophic change occurred, i.e. W3O crystals (A-15 type) with a size of less than 30 nm appeared. Decomposition of the WO3 film started at above 750 degreesC during vacuum heating. W, WO2 and incommensurate WO3 crystals appeared. W3O crystal produced neither intense electron beam irradiation nor vacuum heating. These results will be discussed in terms of the differences caused by excitation with a SR beam, i.e. strong inner shell excitation and ionization of W and O may have taken place.
(C) 2002 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-583X(02)00685-7

Effects of SR irradiation on tin-doped indium oxide thin film prepared by rf magnetron sputtering

M Sasaki, K Hanamoto, Y Kimura, C Kaito, H Miki, Y Nakayama

REVIEW OF SCIENTIFIC INSTRUMENTS 73 ( 3 ) 1384 - 1386 2002.3

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

The effects of synchrotron radiation (SR) irradiation on the electrical properties of tin-doped In2O3 (ITO) thin films prepared by rf magnetron sputtering have been studied. A white SR beam focused by a cylindrical mirror was used to irradiate ITO thin films at doses of 0.35, 1.98, 3.50, and 6.64 mA h. We have achieved resistivity of 2x10(-4) Omega cm on ITO thin film at an irradiation dose of 3.5 mA h without extra heating. The mobility of the ITO films did not decrease after SR irradiation. The electrical properties in connection with the structural change due to SR are discussed. (C) 2002 American Institute of Physics.

DOI： 10.1063/1.1423624

Elevation of antioxidant potency in mice brain by low-dose X-ray irradiation and its effect on Fe-NTA-induced brain damage

Kiyonori Yamaoka, Shuji Mori, Takaharu Nomura, Takehito Taguchi, Takehiko Ito, Katsumi Hanamoto, Shuji Kojima

Physiological Chemistry and Physics and Medical NMR 34 ( 2 ) 119 - 132 2002

Language：English Publishing type：Research paper (scientific journal)

The increase in lipid peroxide levels in mice brain following Fe 3+ administration was about 50% of that when 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine (MPTP) was administered. This may be due to excessive oxidation by Fe3+, and was supported by the decrease in activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX), Na+,K+-ATPase activity and membrane fluidity after Fe3+ administration. Relatively low-dose X-ray irradiation (0.5 Gy) inhibited lipid peroxidation associated with Fe 3+ administration and restored the decreased activities of the above antioxidant enzymes and Na+K+-ATPase, and membrane fluidity to the levels in the non-Fe3+-administered group. In the purine metabolism system, uric acid decreased after Fe3+ administration, which may be due to transient impairment of the system for production of uric acid from xanthine by excessive oxidation by Fe3+. However, 0.5 Gy irradiation inhibited this decrease in uric acid, increasing its level to that in the non Fe3+-administrated group. This may be due to factors such as rapid recovery of the activities of the above antioxidant enzymes and Na+,K+-ATPase, and membrane fluidity after 0.5 Gy irradiation. In addition, since no changes were observed in xanthine and uric acid, increased inosine and hypoxanthine may have advanced to a salvage pathway leading to not xanthine but inosine 5′-monophosphate (IMP).

Growth process of carbyne crystals by synchrotron irradiation

Y Kimura, C Kaito, K Hanamoto, M Sasaki, S Kimura, T Nakada, Y Saito, Y Nakayama

CARBON 40 ( 7 ) 1043 - 1050 2002

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Growth of small carbyne crystals in a thin amorphous carbon film has been observed by high-resolution transmission electron microscopy (HRTEM). The as-deposited film was composed of diamond and graphite crystallites of size 1 nm. Circular alpha-phase carbyne crystals predominantly grew to 20 nm in size and transformed into (alpha+beta)-phase crystals with an elongated shape of 100 nm in length. The typical correlation during the transformation is (220)(alpha)//(301)((alpha+beta)) The c-axes of both grown crystals were oblique to the direction of the electron beam. The growth process of carbyne crystals will be discussed in terms of selective excitation of graphite crystallites by an SR beam. (C) 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0008-6223(01)00242-1

Simple and Easy Method for Measurement of Airborne Radioactive Iodine(125I).

SHIBUYA Koichi, YAMAOKA Kiyonori, NAGAMATSU Tomohiro, HANAMOTO Katsumi, KAWASAKI Shoji, HIRAKI Yoshio

RADIOISOTOPES 51 ( 2 ) 66 - 70 2002

Language：Japanese Publisher：Japan Radioisotope Association

Radioactive iodine isotopes are necessary to be handled carefully, because they scatter easily. As air concentration limits of the radioisotopes are very low levels, we should prepare the measurement technique using a large-volume aspirator and largescale equipments for environment measurement in radiation controlled areas. In the present study, we designed and manufactured a simple set of holder and charcoal filter connected to a foot pump, and we examined the validity of the system. The collecting efficiency of airborne iodine-125 by this system was 0.379±0.107. However, in the case that 10 L air were filtered by this system and counted for 10 min by a NaI (Tl) well-type scintillation counter, it was shown that iodine-125 at air concentration limit could be measured.

DOI： 10.3769/radioisotopes.51.66

Adjustment function among antioxidant substances in acatalasemic mouse brain and its enhancement by low-dose x-ray irradiation

Kiyonori Yamaoka, Takaharu Nomura, Da-Hong Wang, Shuji Mori, Takehito Taguchi, Tetsuya Ishikawa, Katsumi Hanamoto, Shohei Kira

Physiological Chemistry and Physics and Medical NMR 34 ( 2 ) 133 - 144 2002

Language：English Publishing type：Research paper (scientific journal)

The catalase activities in blood and organs of the acatalasemic (C3H/AnLCsbCsb) mouse of the C3H strain are lower than those of the normal (C3H/AnLCsaCsa) mouse. We conducted a study to examine changes in the activities of antioxidant enzymes, such as catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPX), the total glutathione content, and the lipid peroxide level in the brain, which is more sensitive to oxidative stress than other organs, at 3, 6, or 24 hr following X-ray irradiation at doses of 0.25, 0.5, or 5.0 Gy to the acatalasemic and the normal mice. No significant change in the lipid peroxide level in the acatalasemic mouse brain was seen under non-irradiation conditions. However, the acatalasemic mouse brain was more damaged than the normal mouse brain by excessive oxygen stress, such as a high-dose (5.0 Gy) X-ray. On the other hand, we found that, unlike 5.0 Gy X-ray, a relatively low-dose (0.5 Gy) irradiation specifically increased the activities of both catalase and GPX in the acatalasemic mouse brain making the activities closer to those in the normal mouse brain. These findings may indicate that the free radical reaction induced by the lack of catalase is more properly neutralized by low dose irradiation.

Effects of carbon implantation on the electrical properties of amorphous In2O3 thin film

K Hanamoto, M Sasaki, H Miki, Y Nakayama

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 184 ( 3 ) 371 - 377 2001.11

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Carbon ions with an energy of 30 keV have been implanted into amorphous In2O3 thin films at doses of 1 x 10(15) -2 x 10(16) cm(-2). After implantation the films were annealed in air and subsequently in a vacuum at 350 degreesC for 1 h. The electrical resistivities of carbon-implanted films decreased due to the increase in the carrier concentration. However, the whole properties were not much improved compared to a previous experiment by the use of crystalline In2O3 film as a starting material. The relation between the crystal structure and the electrical property will be discussed. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-583X(01)00788-1

Effect of SR irradiation on In2O3 film

K Hanamoto, A Hirai, M Sasaki, Y Kimura, K Miyatani, C Kaito, Y Nakayama

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 467 1213 - 1216 2001.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The effect of SR irradiation on the crystal growth of indium oxide films prepared by electron-beam evaporation have been studied by X-ray diffraction and high-resolution electron microscopy. An as-deposited film showed In2O3 crystallites with a size of 2-10 nm. The crystallites were destroyed by SR irradiation under oxygen flow, SR irradiation without oxygen flow showed the growth of In2O3 crystallites up to 20 nm in size with accompanying deoxidation and indium-particle growth. The as-deposited film was composed of variously oriented particles. Periodic oxygen decomposition of the film preferentially took place on the (0 0 1)-oriented particle. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-9002(01)00618-0

Effect of SR irradiation on crystallization of amorphous tin oxide film

Y Kimura, T Kobayashi, K Hanamoto, M Sasaki, S Kimura, T Nakada, Y Nakayama, C Kaito

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 467 1221 - 1224 2001.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

In order to see the effect of SR irradiation on crystal growth., crystallization of tin oxide films has been performed in vacuum under SR irradiation, A thin amorphous tin oxide film 50 nm thick was prepared on the carbon substrate by vacuum evaporation of SnO2 power, A SnO crystal appeared between 450-500 degreesC upon vacuum heating, with a preferred orientation of (0 0 1). By SR irradiation using a cylindrical mirror for 20 s, the SnO crystal appeared with the preferred orientation of (1 1 1). The crystal with the crystallographic shear structure was grown by SR irradiation. This growth under a SR beam is discussed in terms of SR beam excitation of lone-pair electrons seen in the SnO crystal structure. (C). 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-9002(01)00624-6

Carbyne formation by synchrotron radiation

C Kaito, Y Kimura, K Hanamoto, M Sasaki, S Kimura, T Nakada, Y Saito, C Koike, Y Nakayama

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 467 1217 - 1220 2001.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Thin carbon films prepared by vacuum evaporation using the arc method were mounted on a standard electron microscope copper grid. They were irradiated by white synchrotron radiation (SR) beam by the use of cylindrical and toroidal mirrors. The irradiated film was examined using a high-resolution electron microscope alpha and alpha + beta mixture carbyne crystals were grown in round and the elongated shapes. The round crystals were composed of 5-10 nm crystallites of a carbyne form. The elongated crystal grew into a single crystal 100 nm in size. The c-axes of both grown crystals were oblique to the film. The growth of the carbynes was discussed as being the result of nucleation due to graphite microcrystallites formed by SR beam irradiation. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-9002(01)00575-7

Electrical and optical properties of boron and nitrogen implanted In2O3 thin films

K Hanamoto, M Sasaki, K Miyatani, C Kaito, H Miki, Y Nakayama

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 173 ( 3 ) 287 - 291 2001.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Electrical and optical properties of In2O3 thin films doped with boron and nitrogen have been studied. Boron and nitrogen ions were implanted into In2O3 thin films with an energy of 25 and 35 keV, respectively, at doses of 1 x 10(15)-1.6 x 10(16) cm(-2). After implantation the films were annealed for 1 h in air and subsequently for 1 h in a vacuum. After the two-step annealing at 350 degreesC, the electrical resistivity of the boron implanted sample with a dose of 4 x 10(15) cm(-2) achieved 4.4 x 10(-4) Omega cm with an averaged optical transmittance of 84% at a wavelength between 380 and 780 nm. On the other hand, for nitrogen implanted samples, the resistivity did not improve by ion implantation but the optical transmittance was unchanged. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-583X(00)00334-7

Electrical and optical properties of carbon implanted In2O3 thin film

K Hanamoto, M Sasaki, T Yoneda, K Miyatani, H Miki, C Kaito, Y Nakayama

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 168 ( 3 ) 389 - 394 2000.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Electrical and optical properties of In2O3 thin film with carbon ion implantation have been studied. The location of the implanted carbon in the film was also investigated by means of a high-resolution electron microscope. Carbon ions were implanted into In2O3 thin films with an energy of 30 keV at doses of 1 x 10(15) to 2 x 10(16) cm(-2). After implantation the films were annealed for 1 h in air and subsequently for 1 h in a vacuum. After the two step annealing at 350 degrees C, the electrical resistivity achieved for a sample with an ion dose of 5 x 10(15) cm(-2) was 5.4 x 10(-4) Ohm cm with an optical transmittance of 82% at a wavelength of 550 nm. (C) 2000 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-583X(99)01201-X

Low-resistivity highly transparent indium-tin-oxide thin films prepared at room temperature by synchrotron radiation ablation

Y Akagi, K Hanamoto, H Suzuki, T Katoh, M Sasaki, S Imai, M Tsudagawa, Y Nakayama, H Miki

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS 38 ( 12A ) 6846 - 6850 1999.12

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN J APPLIED PHYSICS

High-transparency, low-electrical-resistivity indium-tin-oxide (ITO) thin films were prepared on quartz substrates using synchrotron radiation ablation at room temperature. The films had a low resistivity (rho = 1.3 x 10(-4) Omega-cm) and high-transparency properties in the visible region (T = 83% at 550nm). X-ray diffraction patterns indicate that the crystalline ITO film was obtained by room-temperature deposition.

DOI： 10.1143/JJAP.38.6846

The combined application of PIXE analysis and thermoluminescence (TL) dating for elucidating the origin of iron manufacturing in Japan

N Hagihara, S Miono, Z Chengzhi, Y Nakayama, K Hanamoto, S Manabe

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 150 ( 1-4 ) 635 - 639 1999.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

For elucidating the origin of iron manufacturing in Japan, the usefulness of PIXE analysis was reconfirmed and a new technique of thermoluminescence (TL) dating was applied. Through reproducing experiments of iron manufacturing and forging, PIXE analysis was tested for classifying the iron slag produced from these two different process. The TL dating method was improved for experiments with the iron manufacturing furnace, burnt at high temperature (about 1300 K) and irradiated with relatively low dose. Utilizing PIXE analysis, the iron manufacturing furnace can be distinguished from the older forging furnace used for the imported iron plate. Adopting TL dating, the oldest iron manufacturing furnace can be found out. Some ancient samples in Japan were used as a test of this combined application, and the results were positive, thus proving the suitability of the method. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-583X(98)01077-5

The discovery of native iron nuggets in the 250 my old bedded chert of Sasayama section, Japan: provenance estimated by PIXE analysis

S Miono, Y Nakayama, K Hanamoto

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 150 ( 1-4 ) 516 - 519 1999.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

A large number of micron sized native iron nuggets (micro iron nugget) occurs in the Triassic-Permian bedded chert. Judging from PIXE analyses and microscopic observations, an interstellar origin is deduced. The occurrence of micro iron nuggets is remarkable and is strongly suggestive of the existence of a neu accretional mechanism in space. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-583X(98)00917-3

Study on thin SiC layer split by hydrogen implantation in SiC

T Hosono, K Hanamoto, T Ueno, Kitabatake, I, M Sasaki, Y Nakayama, S Nishino

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 149 ( 1-2 ) 67 - 71 1999.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

A thin SiC layer split by H-2 implantation with an energy of 160 keV in SiC wafer has been studied by a new method of optical reflectance interference spectrometry (ORIS). The ORIS spectra revealed that thin SiC layer caused by microsplits is formed over almost whole region of the samples and the thickness of the thin SiC layer is about 630 nm for this implantation. The thickness split has been discussed in connection with the results of atomic force microscopy (AFM) and Rutherford backscattering spectrometry/channeling (RBS/C) The RBS/C measurements also indicated that the surface lattice defects of SiC due to H-implantation decreased by beat treatments. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-583X(98)00623-5

Annealing effects on the hardening of electroless plated Ni-P layer by boron implantation

K Hanamoto, M Sasaki, T Miyashita, Y Kido, Y Nakayama, Y Kawamoto, M Fujiwara, R Kaigawa

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 145 ( 3 ) 391 - 394 1998.11

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Annealing effects of hardening of electroless plated Ni-P layer on an iron based alloy have been studied in connection with 200 keV boron ion implantation at a dose of 1 x 10(17) ions/cm(2). Increases of Vickers hardness in the near-urface region were observed to an extent of 17% for the pre-annealed specimens compared to unimplanted ones. Post-nnealed specimens did not show effective hardening by the implantation treatment. The chemical states of implanted ions were studied by X-ray photoelectron spectroscopy (XPS) and the results may suggest that the increase of hardness is not due to the precipitation of nickel borides, but rather due to amorphization of Ni and Ni3P. (C) 1998 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0168-583X(98)00419-4

Anomalous depth profile of implanted fluorine ions in SiO2/Si

K Hanamoto, H Yoshimoto, T Hosono, A Hirai, Y Kido, Y Nakayama, R Kaigawa

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 140 ( 1-2 ) 124 - 128 1998.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Fluorine ions have been implanted into SiO2/Si with an energy of 30 keV at doses of 0.5 and 1 x 10(17) ions/cm(2). Depth profiles of fluorine have been studied by X-ray photoelectron spectroscopy (XPS) for both as-implanted and annealed samples. It was found that depth profiles of fluorine in SiO2/Si did not agree with the predicted Gaussian profiles and showed an enhancement of fluorine concentration in SiO2 region far as-implanted samples. It is thought that anomalous depth profiles may be due to rather high diffusion coefficient in Si than that in SiO2 as a result of fluorine implantation. After annealing at 700 degrees C for 30 min, fluorine concentrations considerably decreased in Si region compared with in SiO2 region. It could be considered that the oxide layers prevent the fluorine diffusion and the fluorine is trapped at around the SiO2/Si interface. (C) 1998 Elsevier Science B.V.

DOI： 10.1016/S0168-583X(98)00107-4

Structure and crystallization of Sb-Se films prepared by vacuum evaporation method

C Kaito, T Fujita, T Kimura, K Hanamoto, N Suzuki, S Kimura, Y Saito

THIN SOLID FILMS 312 ( 1-2 ) 93 - 98 1998.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

In order to clarify the cause of crystallization into a spherical crystal of low symmetry from amorphous films, various compounds of the Sb-Se system have been prepared and crystallization due re intense electron beam irradiation has been observed in situ. It was revealed that crystallization of small Sb crystals with (0001) orientation is necessary to form the spherical Sb,Se, crystal. (C) 1998 Elsevier Science S.A.

DOI： 10.1016/S0040-6090(97)00690-1

Effect of fluorine ion implantation on the microstructure and microhardness of AISI 440C stainless steel

K Hanamoto, M Sasaki, T Miyashita, Y Kido, Y Nakayama, Y Kawamoto, M Fujiwara, R Kaigawa

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 129 ( 2 ) 228 - 232 1997.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

AISI 440C stainless steel along with pure iron and chromium have been implanted with 30 keV fluorine ions at doses from 5 x 10(16) to 6 x 10(17) ions/cm(2) and surface hardnesses of the 440C steel have been examined. Implanted regions inside the specimens were studied by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results of XPS and XRD measurements indicate the formation of FeF2 and suggest small grains of CrF2 and non-stoichiometric chromium fluorides in 440C steel. It may be concluded that an increase of the surface hardness in fluorine implanted 440C steel is related to precipitation of metal fluorides and surface oxidation.

DOI： 10.1016/S0168-583X(97)00227-9

DISKTRON ACCELERATOR

M SHOJI, K TAKAHASHI, K HANAMOTO, H TSUJI, M TSUBAKIHARA, T NAKABAYASHI, K TSUCHIDA, N OKADA, H NAKANO, K FURUTA, R ONO, Y NAKAYAMA, Y MIYAKE

REVIEW OF SCIENTIFIC INSTRUMENTS 64 ( 9 ) 2466 - 2474 1993.9

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

A new type of low-energy ion accelerator has been developed. It includes an eight-storied Disktron generator, newly developed accelerating tubes which hold up to 4 MV/m, both single and tandem acceleration capability, and a compound negative ion source. The Disktron generates 3.2 MV with a dummy load and 2.2 MV with ion beams, and has a voltage stability better than 10(-3) at around 1 MV with a corona feedback stabilizer or a generating voltmeter feedback stabilizer only. The highly stabilized voltage of the Disktron has particularly been allowed to form an ion microbeam of about 1-mum diameter.

DOI： 10.1063/1.1143905

THEORETICAL CONSIDERATION OF INTENSITY OF AN X-RAY MICROBEAM FORMED BY A HOLLOW GLASS PIPE

K FURUTA, Y NAKAYAMA, M SHOJI, R KAIGAWA, K HANAMOTO, H NAKANO, Y HOSOKAWA

REVIEW OF SCIENTIFIC INSTRUMENTS 64 ( 1 ) 135 - 142 1993.1

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

Intensities of x-ray microbeams formed by the 250-mm-long hollow glass pipes of inner diameters of 27.4, 23.0, and 18.8 mum have been theoretically investigated, by taking account of the slope distribution of microprojections (surface roughness) on the pipe inner wall, using the Monte Carlo method. The intensities for all the pipes calculated on the supposition that each pipe inner wall is perfect (i.e., zero rms of the slope distribution) have been much greater than the experimental values in the x-ray energy region from 6.93 to 19.6 keV. Assuming the slope rms from 2.5 X 10(-4) rad to 3.3 X 10(-3) rad, the calculated results have agreed with the experimental values. Discussions on the results for all the pipes are given in relation to the x-ray anomalous dispersion, the penetration of x rays, the intensity distribution on the x-ray sources used, undulation of the pipes, and the presence of microdust in the pipes.

DOI： 10.1063/1.1144427

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