• Title/Summary/Keyword: Secondary radiation

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Statistical Analysis Using Living Radiation Survey Data on Processed Products (가공제품에 대한 생활주변방사선 실태조사 자료를 활용한 통계분석)

  • Choi, Kyoungho;Cho, Jung Keun
    • Journal of radiological science and technology
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    • v.43 no.2
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    • pp.123-128
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    • 2020
  • Radiation Following the 2011 Fukushima nuclear accident in Japan, public interest and anxiety about radiation safety increased, and vague anxiety about commonly exposed living radiation was generated. The Atomic Energy Safety Commission has been conducting a survey of processed products that advertise "negative ions" and "far-infrared" emissions under the Living Radiation Safety Management Act. In this study, in-depth analysis was performed from a statistical point of view using the measurement data presented in the Nuclear Safety Committee's actual survey analysis report as secondary data. As a result, there was a statistically significant difference (p<0.005) between latex and civil affairs products. There were also statistically significant differences (p<0.05) in the results of testing whether there were significant differences in the annual exposure dose between groups after categorizing 71 civil products, including radon beds, into bed, bedding, and living and other categories. The correlation analysis results also confirm that, as is commonly known, the annual doses received from processed products are associated with radon derived from U-238 and Th-232.

Physiological and molecular analysis of OsTPS30 by gamma irradiation

  • Kim, Se Won;Jung, In Jung;Kim, Sang Hoon;Choi, Hong-Il;Kang, Si-Yong;Kim, Jin-Baek
    • Journal of Plant Biotechnology
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    • v.46 no.2
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    • pp.88-96
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    • 2019
  • Terpenes constitute a large class of secondary metabolites in plants. The Oryza sativa terpene synthase is a vital gene in plant defense response. In this study, the molecular and physiological functions of Oryza sativa terpene synthase 30 (OsTPS30, LOC_Os08g07080) were investigated after exposure of the seeds and plants to gamma-rays. The OsTPS30 expression was slightly induced at 200 Gray (Gy), but was significantly induced at 400 Gy. The total terpenoid was synthesized more in OsTPS30-overexpressing (OX-OsTPS30) Arabidopsisthaliana plants than in wild-type (WT) plants. The OX-OsTPS30 plants exhibited resistance to gamma-rays, as compared to WT. The OX-OsTPS30 plants had significantly increased height and weight after gamma irradiation. Additionally, the activity of antioxidant enzymes was increased more in OX OsTPS30 plants than in WT plants after gamma irradiation. Furthermore, the OsTPS30-GFP fusion protein was mostly localized in the chloroplast, suggesting that OsTPS30 is putative MEP pathway-related terpene synthase.

Hemodynamic Consideration for Endoleak and Aneurysm Size Change after the Stent-Graft Application of Aortic Aneurysm

  • Park, Jea-Hyung;Jae, Hwan-Joon;Lee, Whal;Chung, Jin-Wook
    • International Journal of Vascular Biomedical Engineering
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    • v.2 no.2
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    • pp.10-15
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    • 2004
  • Purpose: In the treatment of aortic aneurysm, endovascular stent-graft application has become an established method of treatment. To observe the outcomes of the procedure as the size change of aneurysm in relation with endoleak, a retrospective analysis was done for the consecutive cases who undertook the procedure. Materials & Method: Stent-graft was applied to the aortic aneurysm in 33 patients. The location of the aneurysm was thoracic in 11 patients and abdominal in 22 patients. CT angiographic was done for the follow-up evaluation to analyze the aneurysm size and the presence of endoleak. Results: Technical success rate was 97% (32/33). The primary success rate without endoleak was 84% (28/33). The secondary success was 90% (30/33). During the follow-up period of 3 months to 7years and 6months in 26 patients, a secondary endoleak developed in 5 cases. Post-implantation syndrome developed in 17 cases (51%). Among the 14 cases with follow-up imaging data for size, endoleak was negative in 10 cases. The aneurysm decreased in 5 cases, stable in size in 4 cases and enlarged in one case (10%).Among the 4 cases with endoleak positive, the aneurysm enlarged in two cases (50%). Conclusion: In the stent-graft application for aortic aneurysm, there is high chance of decrease of aneurysm size in those cases with endoleak negative. However, the aneurysm may increase and eventually rupture in the cases with en do leak positive. Close observation with CT angiography is necessary for the evaluation for the presence of endoleak and size change.

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Evaluation of the Radiation Dosage Flowing out of the Hot Cell During Synthesis of 18FDG (18FDG 합성시 핫셀장비 외부로 유출 방사선의 선량 평가)

  • Jung, Hongmoon;Cho, June ho;Jung, Jaeeun;Won, Doyeon
    • Journal of the Korean Society of Radiology
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    • v.7 no.5
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    • pp.365-369
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    • 2013
  • Intravenous injection is administered with radioactive medical isotopes to detect disease on Positron Emission Tomography (PET). In this case, typically, $^{18}FDG$ (Fluorodeoxyglucose) is used as a radioactive medicine. Cassette equipment is needed to synthesize deoxyglucose with $^{18}F$, produced by medical cyclotron. Production of radioactive medicine creates a lot of radiation, thus Hot Cell is used to shield a secondary radiation. We measured the radiation dosage flowing out of the hot cell during synthesis of $^{18}FDG$ or distribution. The purpose of this study is to provide the information of radiation dosage regarding the occupational exposure that unintentionally occurs during the synthesis of $^{18}FDG$. In conclusion, we confirmed the radiation dosage out of the hot cell during the $^{18}FDG$ synthesis. Especially, we observed that the radiation flowed out through the lead window, attached as a view port. Thus, it is considered that the improvement of a lead window is necessary in order to decrease the occupational exposure during the $^{18}FDG$ synthesis.

Glioblastoma after Radiotherapy for Pituitary Adenoma (뇌하수체 선종의 방사선치료 후 발생한 교모세포종 - 증례 보고 -)

  • Lee Jong-Young;Park Kyung-Ran;Kim Hun-Joo;Lee Chong-In;Kim Myung-Soon;Jung Soon-Hee
    • Radiation Oncology Journal
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    • v.17 no.4
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    • pp.287-292
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    • 1999
  • A 39-year-old woman developed a glioblastoma about 7 years and 10 months after local radiotherapy (45 Gy) for pituitary adenoma. Clinical and histopathological details are presented, and previously reported cases of radiation-induced glioma are reviewed.

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Multimodality Treatment for Patients with Node-Positive Prostate Cancer: the Role of Radiation Therapy

  • Ochiai, Satoru;Nomoto, Yoshihito;Kobayashi, Shigeki;Yamashita, Yasufumi;Watanabe, Yui;Toyomasu, Yutaka;Kawamura, Tomoko;Takada, Akinori;II, Noriko;Sakuma, Hajime
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1625-1630
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    • 2016
  • Prostate cancer is the secondary most frequently diagnosed cancer in the world. Although numerous prospective randomized trial have been conducted to guide the management of patients with localized or locally advanced prostate cancer, few clinical trials targeting node-positive prostate cancer have been reported. Therefore, there are still controversies in the optimal management of node-positive prostate cancer. Recently, efficacy of multimodality treatment, including radiation therapy (RT), for such patients has been reported in several articles. The results indicate potential benefit of RT both in adjuvant therapy after prostatectomy and in definitive therapy for node-positive prostate cancer. The aim in this article was to summarize the current evidence for RT and evaluate the role in multimodality treatment for patients with node-positive prostate cancer.

Electrochemical Study on PVDF-HFP/Silylated Al2O3-coated PE Separators using the Electron Beam Irradiation for Lithium Secondary Battery (전자선을 이용한 PVDF-HFP/Silylated Al2O3가 코팅된 리튬 이차 전지용 폴리에틸렌 분리막의 전기화학적 특성 연구)

  • Sohn, Joon-Yong;Shin, Junhwa;Nho, Young-Chang
    • Journal of Radiation Industry
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    • v.4 no.4
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    • pp.359-364
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    • 2010
  • PVDF-HFP (binder)/silylated alumina (inorganic particle)-coated PE (polyethylene) separators were with various compositions of binder and inorganic particle were prepared by a dip-coating process with humidity control (R.H. 25% and 50%) using electron beam irradiation. The morphology of the coated PVDF-$HFP/Al_2O_3$ layer with various compositions of PVDF-HFP and $Al_2O_3$, and humidity condition was found to be an important factor in determining ionic conductivity of the prepared separators. The PVDF-$HFP/Al_2O_3$ (5/5)-coated PE separator prepared at R.H. 50% followed by electron beam irradiation at 200 kGy was applied for lithium-ion polymer battery and the cell test results showed improved high-rate discharge performance and better cyclic stability compared to the cells with the bare PE and the PVDF-HFP-coated PE separators.

Dosimetry according to the Object Thickness (피사체(被射體)두께에 따른 선량분포(線量分布))

  • Lee, Sang-Suk;Park, Sung-Ock
    • Journal of radiological science and technology
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    • v.2 no.1
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    • pp.85-88
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    • 1979
  • When X-radiation passes through the human body; some is transmitted some is truly absorbed, and some is scattered. In diagnostic radiography, scattered radiation can reach the film if no protective measures are taken. This scattered ray increased density which not necessary for image formation. We studied about absorbtion, scattered ray and the way of get rid of scatter ray according to the x-ray tube kilovoltage and obtained results as follow; 1. Absorbtion ray increased proportion to KVP. 2. Scattered ray increased at high KVP and thick object. 3. Secondary radiation of the primary increased at high KVP and thick object. 4. Remove .ate of scattered ray decreased at thick object and increase at low KVP make use of 6:1 grid ratio

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Performance Analysis of FSO Communication Systems with Photodetector Multiplexing

  • Feng, Jianfeng;Zhao, Xiaohui
    • Current Optics and Photonics
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    • v.1 no.5
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    • pp.440-455
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    • 2017
  • In this paper, we carry out a performance analysis of a two-user free-space optical (FSO) communication system with photodetector multiplexing, in which the two users are defined as the primary user (PU) and secondary user (SU). Unlike common single-user FSO systems, our photodetector multiplexing FSO system deploys a shared detector at the receiver and enables PU and SU to send their own data synchronously. We conduct the performance analysis of this FSO system for two cases: (1) in the absence of background radiation, and (2) in the presence of background radiation. Decision strategies for PU and SU are presented according to the two scenarios above. Exact and approximate conditional symbol-error probability (SEP) expressions for both PU and SU are derived, in an ideal channel with no fading. Average SEP expressions are also presented in the no-background-radiation scenario. Additionally, in some particular cases where the power ratio tends to 0.5 or 1, approximate SEP expressions are also obtained. Finally, numerical simulations are presented under different conditions, to support the performance analysis.