• Title/Summary/Keyword: Ionizing Radiation

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Comparative Study on Human Risk by Ionizing Radiation and Pesticide as Biological Information about Environmental Disaster (환경재해에 관한 생물정보로서의 이온화 방사선과 살충제의 인체 위해성 비교 연구)

  • Kim, Jin-Kyu;Hyun, Soung-Hee
    • Journal of Radiation Protection and Research
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    • v.26 no.4
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    • pp.385-392
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    • 2001
  • Environmental risk factors such as ionizing radiations, heavy metals, and pesticides can cause environmental disasters when they exist in excess. The increases in use of ionizing radiation and agricultural pesticide are somewhat related to the possibility of the disaster. The risk of radiation and pesticide was evaluated by means of the single cell gel electrophoresis (SCGE) assay on the human blood lymphocytes. The lymphocytes were irradiated with $0{\sim}2.0Gy$ of $^{60}Co$ gamma ray. Another groups of lymphocytes were exposed to various concentrations of parathion. Significantly increased tail moment, which was a marker of DNA strand breaks in SCGE assay, showed a clear dose- or concentration-response relationship. Parathion of a recommended concentration for agricultural use ($1mg {\ell}^{-1}$ ) has a strong cytotoxic effect on lymphocytes, which is equivalent to damage induced by 0.1 Gy of ${\gamma}$-ray. Furthermore, $2mg{\ell}^{-1}$ of parathion can give rise to DNA damage equivalent to that induced by 0.25 Gy at which the radiation-induced damage can start to develop into clinical symptoms. The comparative results of this study can provide an experimental basis and biological information for the prevention of environmental disaster.

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Radiation protection in dental clinic (치과에서의 방사선안전관리)

  • Lee, Sam-Sun
    • Imaging Science in Dentistry
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    • v.37 no.3
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    • pp.117-126
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    • 2007
  • Although the diagnostic information provided by radiographs may be of definite benefit to the patients, the radiographic examination does carry the potential for harm from exposure to ionizing radiation. Therefore we should try to expose radiation as low as reasonably achievable and to give diagnostic information to patients as much as possible. All of dentists should have competence in radiation protection. I wish to deal with what we should do for the optimization of radiation protection in dental clinic.

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Evaluation of apoptosis after ionizing radiation in feeding and starving rats

  • Lee, Jae-Hyun;Cho, Kyung-Ja;Hong, Seok-Il;Park, Min-Kyung
    • Korean Journal of Veterinary Pathology
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    • v.2 no.1
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    • pp.37-46
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    • 1998
  • It has been known that $\gamma$-irradiation usually induces cell death in regenerating stem cell in normal tissues like skin, intestine and hematopoietic organ. The experiment were carried out to evaluate the early response of radiation injury in radiosensitive and intermediate radiosensitive tissues in feeding and starving rats with the doses of 3.5 and 7.0 Gy. The results of the study showed that the histological phenomenon was apoptosis in the doses of the radiation as the early response of tissue injury. Apoptosis were showed organ-specific and cellular specific responses suggesting that the selection of apoptosis be exactly focused on highly renewal organs and cells. It was interesting that the rats starved for 72 hours prior to irradiation induced less apoptosis in liver than fed rats. As for cellular responses it appeared that apoptotic cells were mostly distributed in ductal or periportal cells in liver of feeding rats unlikely in liver of Starving rots which showed no difference in zonal distribution. In salivary gland apoptotic cells in fed rats were highly induced in intercalating and ductal cell population than in acinar cell population although unlikely in starved rats. This study showed the value of apoptosis using the detection system of TUNEL for evaluating cellular damage after radiation injury and the diminished effect of starvation on cell damage after ionizing irradiation.

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Space Radiation Shielding Calculation by Approximate Model for LEO Satellites

  • Shin Myung-Won;Kim Myung-Hyun
    • Nuclear Engineering and Technology
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    • v.36 no.1
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    • pp.1-11
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    • 2004
  • Two approximate methods for a cosmic radiation shielding calculation in low earth orbits were developed and assessed. Those are a sectoring method and a chord-length distribution method. In order to simulate a change in cosmic radiation environments along the satellite mission trajectory, IGRF model and AP(E)-8 model were used. When the approximate methods were applied, the geometrical model of satellite structure was approximated as one-dimensional slabs, and a pre-calculated dose-depth conversion function was introduced to simplify the dose calculation process. Verification was performed with mission data of KITSAT-1 and the calculated results were also compared with detailed 3-dimensional calculation results using Monte Carlo calculation. Dose results from the approximate methods were conservatively higher than Monte Carlo results, but were lower than experimental data in total dose rate. Differences between calculation and experimental data seem to come from the AP-8 model, for which it is reported that fluxes of proton are underestimated. We confirmed that the developed approximate method can be applied to commercial satellite shielding calculations. It is also found that commercial products of semi-conductors can be damaged due to total ionizing dose under LEO radiation environment. An intensive shielding analysis should be taken into account when commercial devices are used.

Radiation safety: a focus on lead aprons and thyroid shields in interventional pain management

  • Cheon, Bo Kyung;Kim, Cho Long;Kim, Ka Ram;Kang, Min Hye;Lim, Jeong Ae;Woo, Nam Sik;Rhee, Ka Young;Kim, Hae Kyoung;Kim, Jae Hun
    • The Korean Journal of Pain
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    • v.31 no.4
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    • pp.244-252
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    • 2018
  • C-arm fluoroscopy is useful equipment in interventional pain management because it helps to guide correct needle targeting for the accurate injection and drug delivery. However, due to increased use of C-arm fluoroscopy in various pain procedures, the risk of radiation exposure is a significant concern for pain physicians. The harmful biological effects of ionizing radiation on the human body are well known. It is therefore necessary to strive to reduce radiation exposure. Lead aprons with thyroid shields are the most fundamental radiation protective devices for interventional procedures, and are very effective. However, the operator's radiation safety cannot be guaranteed because pain physicians seem to lack sufficient interest, knowledge, and awareness about radiation safety. Also, inappropriate care and use of radiation protective devices may result in a higher risk of radiation exposure. The purpose of this article was to review the literature on radiation safety with a focus on lead aprons and thyroid shields and present recommendations related to those devices during C-arm fluoroscopic-guided interventions by pain physicians.