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Ogawara R, Suda M, Hagihara T, Kodaira S, Hamano T. DISCRIMINATION METHOD FOR GAMMA RAY DOSES IN NEUTRON FIELDS USING AN IONIZATION CHAMBER WITH ATTENUATION FILTERS. RADIATION PROTECTION DOSIMETRY 2019; 183:280-284. [PMID: 30726975 DOI: 10.1093/rpd/ncz002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 06/09/2023]
Abstract
Neutron fields produced by an accelerator-driven neutron source are generally mixed radiation fields that consist of fast neutrons and gamma rays. To estimate the biological effects of fast neutrons precisely, the gamma ray dose contamination must be evaluated in neutron fields. In this work, we developed a discrimination technique for absorbed doses (60Co gamma-ray equivalent) of fast neutrons and gamma rays using an ionization chamber. The filter thickness dependences of the absorbed doses of fast neutrons and gamma rays are different for a given filter material. Thus, the absorbed doses of each type of radiation were distinguished by fitting the dose attenuation curve, which was measured with an ionization chamber and attenuation filters, with a two-component exponential function. The absorbed dose of fast neutrons and gamma rays with no attenuation filter was evaluated from the y-intercept of the fitting function. This technique was demonstrated in two neutron fields produced by 4 MeV proton and deuteron bombardment of a 9Be target. The thicknesses of the polyethylene attenuation filters were 0-350 mm. The dose attenuation coefficients of fast neutrons obtained by the two-component exponential fitting function for the 9Be(p,n)9 and 9Be(d,n) reactions showed differences of 1.5 and 1.7%, respectively, from the reference measurements using a CR-39 plastic nuclear track detector. The absorbed dose contributions of gamma rays in neutrons fields of the 9Be(p,n)9B and 9Be(d,n) reactions were evaluated as 30.2 ± 3.24% and 20.4 ± 5.16%, respectively, without polyethylene filters.
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Affiliation(s)
- R Ogawara
- National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - M Suda
- National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - T Hagihara
- National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - S Kodaira
- National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - T Hamano
- National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
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Sasaki N, Watanabe A, Asakawa T, Sasaki M, Hoshi N, Naito Z, Furusawa Y, Shimokawa T, Nishihara M. Biological effects of ion beam irradiation on perennial gentian and apple. PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2018; 35:249-257. [PMID: 31819730 PMCID: PMC6879364 DOI: 10.5511/plantbiotechnology.18.0612a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The development of new varieties of perennial plants generally requires lengthy and laborious procedures. In this study, we used ion beam irradiation mutagenesis in an attempt to accelerate the breeding process for perennial plants. We evaluated the biological effects of five ion beam sources (carbon, neon, argon, silicon, and iron) and neutron irradiation on Japanese gentian and apple. These treatments were applied at the National Institute of Radiological Sciences (NIRS) using the Heavy Ion Medical Accelerator in Chiba (HIMAC) and the Neutron-exposure Accelerator System for Biological Effect Experiments (NASBEE). Biological effects were observed in in vitro gentian plants after irradiation with ion beams at <10 Gy, whereas apple trees were less sensitive to ion beam irradiation. The growth of gentians in vitro was repressed by 3 Gy neutron irradiation, while that of grafted apple trees was not affected by 4 Gy neutron irradiation. During in vitro proliferation, seven pink-flowered lines were obtained from originally blue-flowered gentian after C and Ne ion beam irradiation treatments. Genomic and reverse transcription-PCR analyses of these lines suggested that the mutations occurred in the genomic region containing F3'5'H (encoding flavonoid 3',5'-hydroxylase). These results provide useful information for the mutagenesis and breeding of gentian, apple, and other perennial plants.
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Affiliation(s)
- Nobuhiro Sasaki
- Iwate Biotechnology Research Center, 22-174-4 Narita, Kitakami, Iwate 024-0003, Japan
| | - Aiko Watanabe
- Iwate Biotechnology Research Center, 22-174-4 Narita, Kitakami, Iwate 024-0003, Japan
| | - Tomonori Asakawa
- Iwate Agricultural Research Center, 20-1 Narita, Kitakami, Iwate 024-0003, Japan
| | - Makoto Sasaki
- Iwate Agricultural Research Center, 20-1 Narita, Kitakami, Iwate 024-0003, Japan
| | - Nobue Hoshi
- Iwate Agricultural Research Center, 20-1 Narita, Kitakami, Iwate 024-0003, Japan
| | - Zenbi Naito
- Iwate Agricultural Research Center, 20-1 Narita, Kitakami, Iwate 024-0003, Japan
| | - Yoshiya Furusawa
- National Institute of Radiological Sciences, National Institutes of Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan
| | - Takashi Shimokawa
- National Institute of Radiological Sciences, National Institutes of Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan
| | - Masahiro Nishihara
- Iwate Biotechnology Research Center, 22-174-4 Narita, Kitakami, Iwate 024-0003, Japan
- E-mail: Tel: +81-197-68-2911 Fax: +81-197-68-3881
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Shahmohammadi Beni M, Hau TC, Krstic D, Nikezic D, Yu KN. Monte Carlo studies on neutron interactions in radiobiological experiments. PLoS One 2017; 12:e0181281. [PMID: 28704557 PMCID: PMC5509315 DOI: 10.1371/journal.pone.0181281] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 06/28/2017] [Indexed: 11/25/2022] Open
Abstract
Monte Carlo method was used to study the characteristics of neutron interactions with cells underneath a water medium layer with varying thickness. The following results were obtained. (1) The fractions of neutron interaction with 1H, 12C, 14N and 16O nuclei in the cell layer were studied. The fraction with 1H increased with increasing medium thickness, while decreased for 12C, 14N and 16O nuclei. The bulges in the interaction fractions with 12C, 14N and 16O nuclei were explained by the resonance spikes in the interaction cross-section data. The interaction fraction decreased in the order: 1H > 16O > 12C > 14N. (2) In general, as the medium thickness increased, the number of “interacting neutrons” which exited the medium and then further interacted with the cell layer increased. (3) The area under the angular distributions for “interacting neutrons” decreased with increasing incident neutron energy. Such results would be useful for deciphering the reasons behind discrepancies among existing results in the literature.
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Affiliation(s)
- Mehrdad Shahmohammadi Beni
- Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong, China
| | - Tak Cheong Hau
- Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong, China
| | - D Krstic
- Faculty of Science, University of Kragujevac, Kragujevac,Serbia
| | - D Nikezic
- Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong, China.,Faculty of Science, University of Kragujevac, Kragujevac,Serbia
| | - K N Yu
- Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong, China.,State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong, China
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Shahmohammadi Beni M, Krstic D, Nikezic D, Yu KN. A calibration method for realistic neutron dosimetry in radiobiological experiments assisted by MCNP simulation. JOURNAL OF RADIATION RESEARCH 2016; 57:492-498. [PMID: 27380801 PMCID: PMC5045084 DOI: 10.1093/jrr/rrw063] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/23/2016] [Accepted: 05/09/2016] [Indexed: 06/06/2023]
Abstract
Many studies on biological effects of neutrons involve dose responses of neutrons, which rely on accurately determined absorbed doses in the irradiated cells or living organisms. Absorbed doses are difficult to measure, and are commonly surrogated with doses measured using separate detectors. The present work describes the determination of doses absorbed in the cell layer underneath a medium column (DA) and the doses absorbed in an ionization chamber (DE) from neutrons through computer simulations using the MCNP-5 code, and the subsequent determination of the conversion coefficients R (= DA/DE). It was found that R in general decreased with increase in the medium thickness, which was due to elastic and inelastic scattering. For 2-MeV neutrons, conspicuous bulges in R values were observed at medium thicknesses of about 500, 1500, 2500 and 4000 μm, and these were attributed to carbon, oxygen and nitrogen nuclei, and were reflections of spikes in neutron interaction cross sections with these nuclei. For 0.1-MeV neutrons, no conspicuous bulges in R were observed (except one at ~2000 μm that was due to photon interactions), which was explained by the absence of prominent spikes in the interaction cross-sections with these nuclei for neutron energies <0.1 MeV. The ratio R could be increased by ~50% for small medium thickness if the incident neutron energy was reduced from 2 MeV to 0.1 MeV. As such, the absorbed doses in cells (DA) would vary with the incident neutron energies, even when the absorbed doses shown on the detector were the same.
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Affiliation(s)
- Mehrdad Shahmohammadi Beni
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong
| | | | - Dragoslav Nikezic
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong Faculty of Science, University of Kragujevac, Serbia
| | - Kwan Ngok Yu
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong
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Ng CYP, Kong EY, Kobayashi A, Suya N, Uchihori Y, Cheng SH, Konishi T, Yu KN. Non-induction of radioadaptive response in zebrafish embryos by neutrons. JOURNAL OF RADIATION RESEARCH 2016; 57:210-219. [PMID: 26850927 PMCID: PMC4915534 DOI: 10.1093/jrr/rrv089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 09/13/2015] [Accepted: 11/03/2015] [Indexed: 06/05/2023]
Abstract
In vivo neutron-induced radioadaptive response (RAR) was studied using zebrafish (Danio rerio) embryos. The Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) facility at the National Institute of Radiological Sciences (NIRS), Japan, was employed to provide 2-MeV neutrons. Neutron doses of 0.6, 1, 25, 50 and 100 mGy were chosen as priming doses. An X-ray dose of 2 Gy was chosen as the challenging dose. Zebrafish embryos were dechorionated at 4 h post fertilization (hpf), irradiated with a chosen neutron dose at 5 hpf and the X-ray dose at 10 hpf. The responses of embryos were assessed at 25 hpf through the number of apoptotic signals. None of the neutron doses studied could induce RAR. Non-induction of RAR in embryos having received 0.6- and 1-mGy neutron doses was attributed to neutron-induced hormesis, which maintained the number of damaged cells at below the threshold for RAR induction. On the other hand, non-induction of RAR in embryos having received 25-, 50- and 100-mGy neutron doses was explained by gamma-ray hormesis, which mitigated neutron-induced damages through triggering high-fidelity DNA repair and removal of aberrant cells through apoptosis. Separate experimental results were obtained to verify that high-energy photons could disable RAR. Specifically, 5- or 10-mGy X-rays disabled the RAR induced by a priming dose of 0.88 mGy of alpha particles delivered to 5-hpf zebrafish embryos against a challenging dose of 2 Gy of X-rays delivered to the embryos at 10 hpf.
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Affiliation(s)
- Candy Y P Ng
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Ave., Kowloon Tong, Hong Kong
| | - Eva Y Kong
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Ave., Kowloon Tong, Hong Kong
| | - Alisa Kobayashi
- Research, Development and Support Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Noriyoshi Suya
- Research, Development and Support Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan
| | - Yukio Uchihori
- Research, Development and Support Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan
| | - Shuk Han Cheng
- Department of Biomedical Sciences, City University of Hong Kong, Tat Chee Ave., Kowloon Tong, Hong Kong State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Ave., Kowloon Tong, Hong Kong
| | - Teruaki Konishi
- Research, Development and Support Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan
| | - Kwan Ngok Yu
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Ave., Kowloon Tong, Hong Kong State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Ave., Kowloon Tong, Hong Kong
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Ng C, Kong E, Konishi T, Kobayashi A, Suya N, Cheng S, Yu K. Low-dose neutron dose response of zebrafish embryos obtained from the Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) facility. Radiat Phys Chem Oxf Engl 1993 2015. [DOI: 10.1016/j.radphyschem.2015.05.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Okumura K, Kinashi Y, Kubota Y, Kitajima E, Okayasu R, Ono K, Takahashi S. Relative biological effects of neutron mixed-beam irradiation for boron neutron capture therapy on cell survival and DNA double-strand breaks in cultured mammalian cells. JOURNAL OF RADIATION RESEARCH 2013; 54:70-75. [PMID: 22966174 PMCID: PMC3534280 DOI: 10.1093/jrr/rrs079] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 07/27/2012] [Accepted: 08/03/2012] [Indexed: 06/01/2023]
Abstract
Understanding the biological effects of neutron mixed-beam irradiation used for boron neutron capture therapy (BNCT) is important in order to improve the efficacy of the therapy and to reduce side effects. In the present study, cell viability and DNA double-strand breaks (DNA-DSBs) were examined in Chinese hamster ovary cells (CHO-K1) and their radiosensitive mutant cells (xrs5, Ku80-deficient), following neutron mixed-beam irradiation for BNCT. Cell viability was significantly impaired in the neutron irradiation groups compared to the reference gamma-ray irradiation group. The relative biological effectiveness for 10% cell survival was 3.3 and 1.2 for CHO-K1 and xrs5 cells, respectively. There were a similar number of 53BP1 foci, indicators of DNA-DSBs, in the neutron mixed-beam and the gamma-ray groups. In addition, the size of the foci did not differ between groups. However, neutron mixed-beam irradiation resulted in foci with different spatial distributions. The foci were more proximal to each other in the neutron mixed-beam groups than the gamma-ray irradiation groups. These findings suggest that neutron beams may induce another type of DNA damage, such as clustered DNA-DSBs, as has been indicated for other high-LET irradiation.
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Affiliation(s)
- Kakuji Okumura
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennann-gun, Osaka 590-0494, Japan
| | - Yuko Kinashi
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennann-gun, Osaka 590-0494, Japan
| | | | | | | | - Koji Ono
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennann-gun, Osaka 590-0494, Japan
| | - Sentaro Takahashi
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennann-gun, Osaka 590-0494, Japan
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Kitagawa A, Fujita T, Goto A, Hattori T, Hamano T, Hojo S, Honma T, Imaseki H, Katagiri K, Muramatsu M, Sakamoto Y, Sekiguchi M, Suda M, Sugiura A, Suya N. Status of ion sources at National Institute of Radiological Sciences. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:02A332. [PMID: 22380179 DOI: 10.1063/1.3670742] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The National Institute of Radiological Sciences (NIRS) maintains various ion accelerators in order to study the effects of radiation of the human body and medical uses of radiation. Two electrostatic tandem accelerators and three cyclotrons delivered by commercial companies have offered various life science tools; these include proton-induced x-ray emission analysis (PIXE), micro beam irradiation, neutron exposure, and radioisotope tracers and probes. A duoplasmatron, a multicusp ion source, a penning ion source (PIG), and an electron cyclotron resonance ion source (ECRIS) are in operation for these purposes. The Heavy-Ion Medical Accelerator in Chiba (HIMAC) is an accelerator complex for heavy-ion radiotherapy, fully developed by NIRS. HIMAC is utilized not only for daily treatment with the carbon beam but also for fundamental experiments. Several ECRISs and a PIG at HIMAC satisfy various research and clinical requirements.
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Affiliation(s)
- A Kitagawa
- National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan
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