RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Volume 63 , Issue 1
Showing 1-6 articles out of 6 articles from the selected issue
Article
  • Yukio TAKIZAWA, Junsuke YAMASHITA, Seiki ISHIGOUKA
    2014 Volume 63 Issue 1 Pages 1-12
    Published: 2014
    Released: January 28, 2014
    JOURNALS OPEN ACCESS
    We examined the protective efficacy of Japanese sake against ionizing X-irradiation and biologically analysed sake for radioprotective compounds. The sake used in this experiment is Junmai-shu (ethanol content, 10.5%) that made only from rice and malted rice. Male C57BL/6JJms mice aged 9 weeks were orally administered 0.6mL sake/mouse within 30min of 7.8Gy whole body irradiation or 0.2mL sake daily for one week prior to and after irradiation control mice received either Futsu‐shu(ethanol content, 15%), pure ethanol(10.5%) or saline. Futsu-shu is made from rice and malted rice with alcohol added. To test the effect of X-ray-induced lethality in mice, we observed short-term survival(30days) rates in the mice after exposure. Mice administered Junmai-shu demonstrated significantly increased survival rate compared with saline(p‹0.01). The survival rates were greatest for the Junmai-shu group followed by the Futsu-shu, ethanol and saline groups. Radioprotection was not solely a result of hydroxyl radical scavenging by ethanol because pure ethanol demonstrated lower protective effect than sake. Sake contains a greater variety and quantity of amino acids than most other alcoholic drinks. Junmai-shu had a much higher amino acid content than Futsu-shu(1771mg/L vs. 932mg/L), suggesting one possible source of radioprotection. Our results reveal that pure ethanol was slightly protective against lethality but to a lesser degree than sake. A high content of amino acids in sake is one of the unique features of sake that provides a radioprotective effect.
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Materials(Data)
  • Yujiro ICHIKAWA, Tomohiro INOUE, Hideo ISHII, Suekazu NAITO, Yoshihiko ...
    2014 Volume 63 Issue 1 Pages 13-30
    Published: 2014
    Released: January 28, 2014
    JOURNALS OPEN ACCESS
    To evaluate the efficacy of decontamination methods with the measurement of 1cm dose equivalent rate and concentration of radioactive caesium in the soil and plants before and after decontamination at Bouken-no-toride located in Chiba Prefectural Kashiwa-no-ha Park, five decontamination methods were examined. 1)Coverage of ground with uncontaminated soil to thickness of 5cm. 2)The topsoil was stripped and removed to the depth of 5cm. 3)Replacement with uncontaminated sand 10 - 20cm depth in sandbox. 4)Lawns were mowed at 2cm length. 5)The interchanging of 10cm of the topsoil with the underlying 20cm of subsoil. The observed 1cm dose equivalent dose reduction rate were 57%, 64%, 74%, 31% and 85%(refer to the decontamination model project article published by JAEA), respectively.
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  • Yujiro ICHIKAWA, Tomohiro INOUE, Suekazu NAITO, Yoshihiko TAKAHASHI
    2014 Volume 63 Issue 1 Pages 31-43
    Published: 2014
    Released: January 28, 2014
    JOURNALS OPEN ACCESS
    This study evaluates the decontamination methods that were examined at 4 different children's parks located in Chiba prefectural housing complexes with measurement of 1cm dose equivalent rate, monitoring γ ray count rates of playground equipment surface, and determining the concentration of radioactive caesium in the soil. Two decontamination methods were examined. 1)Stripped and removed the topsoil containing radioactive caesium in the range of 3 - 5cm depth, subsequently coverage with uncontaminated soil to the thickness of 3cm to the subsoil layer. 2)Replacement with uncontaminated sand 20cm depth in sandbox. Range of the observed1cm dose equivalent reduction rate were 41 - 91%. With the combination of these decontamination methods described above, the measurement value of 1cm dose equivalent rate decreased below 0.23μSv/h. The results of this study indicate that decontamination processes performed at children's parks showed significant efficacy.
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  • Yujiro ICHIKAWA, Tomohiro INOUE, Suekazu NAITO, Yoshihiko TAKAHASHI
    2014 Volume 63 Issue 1 Pages 45-55
    Published: 2014
    Released: January 28, 2014
    JOURNALS OPEN ACCESS
    The efficacy of decontamination methods was evaluated with the measurement of 1cm dose equivalent rate and concentration of radioactive caesium in the soil, plants and water of the pond before and after decontamination at Japanese garden located in Chiba Prefectural Kashiwa-no-ha Park. Examined decontamination methods were:1)The topsoil of walkway was stripped and removed to the depth of 10mm. 2)Washing the stone pavement walkway using high-pressure water jet washer. At the height of 50cm, we observed 45% and 36% of 1cm dose rate equivalent dose reduction rate(the natural dose rate derived from the ground was subtracted) for 1) and 2) decontamination methods respectively. Due to the decontamination process, the measurement value of 1cm equivalent dose rate decreased below 0.23μSv/h at most of the examined sites, which showed significant efficacy of decontamination methods performed at this Japanese garden.
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Review Article
  • Daiki SHINYAMA, Chikako OTA, Atsushi KOIZUMI, Mayumi KUWANO, Futoshi N ...
    2014 Volume 63 Issue 1 Pages 57-68
    Published: 2014
    Released: January 28, 2014
    JOURNALS OPEN ACCESS
    Composite image diagnosis using a hybrid PET/MRI system is beneficial comparing to individual diagnosis of PET functional images and MRI anatomical images in standalone systems. Because the hybrid PET/MRI system makes it possible to detect disease more accurately and quickly. Moreover, it improves staging evaluation, therapy monitoring and follow-up observation. The stand-alone PET and MRI systems have already been established as useful clinical methods and provides complementary information for each other. With the hybrid PET/MRI system, it is expected to cover a wider range of clinical application. In addition, the hybrid system enables us to get highly precise registration information and more accurate fusion images.
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Serial Lecture
Basics and Applications of Mössbauer Spectrometry
  • Shiro KUBUKI, Tetsuaki NISHIDA
    2014 Volume 63 Issue 1 Pages 69-77
    Published: 2014
    Released: January 28, 2014
    JOURNALS OPEN ACCESS
    Vanadate glass is semiconductive with the electrical conductivity(σ) of 10−7 - 10−5 S cm−1, which is caused by 3d electron(polaron) hopping from VVI(or VIII) to VV. Interestingly, a drastic increase of σ from 10−5 to 100 S cm−1 was observed when 20BaO·70V2O5·10Fe2O3 glass was isothermally annealed at around crystallization peak temperature(Tc) of 500°C, a quadrupole splitting(Δ) decreasing from 0.70 to 0.54mm s−1. These results indicate that the increase in was in proportion to the decrease in the local distortion of FeO4 tetrahedra as reflected in of the Mössbauer spectra. Based on the newly obtained results, the vanadate glass is expected to be a promising candidate as a cathode material of secondary battery. It is concluded that Mössbauer spectrometry is one of the essential techniques for the characterization of functional glasses and ceramics.
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