• Title/Summary/Keyword: Dose Rate

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Study of Patient's Position to Reduce Late Complications in High Dose Rate Intracavitary Radiation of the Uterine Cervix Cancer (자궁경부암의 고선량율 강내 방사선치료 시 부작용을 줄이기 위한 적정 치료 자세의 연구)

  • Yun, Hyong-Geun;Shin, Kyo-Chul
    • Radiation Oncology Journal
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    • v.16 no.4
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    • pp.477-483
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    • 1998
  • Purpose : Radiation proctitis and radiation cystitis are frequent and problematic late complications in patients treated with radiation for the uterine cervix cancer. Authors tried to find out the better patient's position in high dose rate intracavitary radiation to reduce the radiation dose of bladder and rectum. Materials and Methods : In 13 patients, Foley Catheters were inserted to patient's bladder and rectum and were ballooned with radioopaque dye. After insertion of a tandem and two ovoids, semi-orthogonal anteroposterior and lateral films were taken in both lithotomy and supine position. The rectal point and bladder point were defined according to the criteria recommended in the ICRU Report 38 with modification. Using these films, all patients' bladder and rectal dose were calculated in both positions (the radiation dose of A point was set to 400 cGy). And also, the distance of bladder and rectum from uterine cervical os was calculated in both positions. Results : The average radiation dose of rectum was 240.7 cGy in lithotomy position and 278.3 cGy in supine position, and the average radiation dose of bladder was 303.5 cGy in lithotomy position and 255.8 cGy in supine position. After the paired t-test, the radiation dose of rectum in lithotomy position was marginally significantly lower than that in supine position, while the radiation dose of bladder in lithotomy position was significantly higher than that in supine position. On the other hand, the average distance between rectum and cervical os was 35.2 mm in lithotomy position and 32.3 mm in supine position. and the average distance between bladder and cervical os was 30.4 mm in lithotomy position and 34.0 mm in supine position. After the paired t-test. the distance between rectum and cervical os in lithotomy position was significantly longer than that in supine position, while the distance between bladder and cervical os in lithotomy position was significantly shorter than that in supine position. Conclusion : The radiation dose of bladder can be reduced in supine position and the radiation dose of rectum can be reduced in lithotomy position, so we can choose appropriate position in each patient.

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Anti-depressant Effect of the Extracts of Aconitum carmichaeli (부자(附子)의 우울증 억제효과에 관한 연구)

  • Chang, Moon-Kyoo;Kim, Geun-Woo;Koo, Byung-Soo
    • Journal of Oriental Neuropsychiatry
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    • v.20 no.3
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    • pp.49-64
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    • 2009
  • Objectives : The water and methanol extracts of Aconitum carmichaeli(Aconiti Tuber Preparat) were investigated for their anti-depressant effects. Methods : In this study, reserpine-induced hypothermia test, tail suspension test and hot plate test. Additionally, the brain monoamine oxidase activity was determined in vivo. Results: In the reserpine-induced hypothermia test, both extracts suppressed the fall of body temperature compared to the control group in a dose-dependent manner, suggesting the inhibition on hypothermia. In the tail suspension test, the methanol extract dose-dependently reduced the duration of immobility by 28.4% at a dose of 1 g/kg compared to control group, which is more effective than the water extract. In the hot plate test, the water extract and methanol extract increased the jump latency time compared to the control group, showing the inhibition rate of 198% and 182%, respectively, at a dose of 1 g/kg. Methanol extracts potently inhibited the brain monoamine oxidase activity in an in vivo assay compared to the control group, showing 84.6% inhibition, but the water extract revealed very weak activity. Conclusions : Above results suggested that the extract of Aconitum carmichaeli can be useful for the prevention and treatment of depression.

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Effects of Low Dose Gamma Radiation on the Growth and Antioxidant Enzyme Activities of Chinese Cabbage (Brassica campestris L.) Seedlings (배추 유식물의 생장과 항산화효소의 활성도에 미치는 저선량 방사선의 효과)

  • 김재성;이영근;백명화;김동희;이영복
    • Korean Journal of Environmental Biology
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    • v.18 no.2
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    • pp.247-253
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    • 2000
  • In order to investigate the stimulatory effect(hormesis) of low dose gamma-radiation on the seeding growth of old seeds with respect to antioxidant defense systems, various doses of gamma radiation to the 5-year-old dried seeds of Chinese cabbage (Brassica campestris L. cv Sulin eockaei). Compared to the new, 1-year- old seeds, old seeds irradiated by low does gamma radiation in the range of 1-2 Gy showed vigor growth as revealed by statistically significant increases both in the germination rates and the leaf size and fresh weight. Further, seedlings grown from seeds treated by low dose gamma radiation showed higher peroxidase and catalase activities than non-treated seedlings. These results suggest that the antioxidant defense systems could be closely related to the stimulatory effects of low dose radiation. [antioxidant enzyme, chinese cabbage, gamma radiation, germination rate, hormesis]

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Performance Evaluation of Gamma ray Shielding of Antimony Shielding Sheet (안티몬 차폐시트의 감마선 차폐 성능평가)

  • Han, Sang-Hyun
    • Journal of radiological science and technology
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    • v.41 no.2
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    • pp.135-140
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    • 2018
  • In this study, the dose of antimony shielding sheet was measured and the shielding rates according to the distance between the radioisotopes and the detector was analyzed according to the type of $^{99m}Tc$, $^{18}F$, $^{201}Tl$, $^{131}I$, $^{123}I$ using the antimony shielding sheet. The detector was used with an inspector. Six sheets of 0.25 mmPb were prepared with 20 cm width and length. Measurement results using $^{99m}Tc$, $^{201}Tl$, and $^{123}I$ showed that as the thickness of the sheet became thicker, the farther the distance from the source to the sheet was, the smaller the transmitted dose amount was measured. It was analyzed that a thickness of 1.50 mm or more was required to obtain a shielding rates of 90% or more. In the experiments of $^{18}F$ and $^{131}I$, the dose value was highest when 0.25 mm sheet was used, and the shielding rates was negative, unlike the results of other radioisotopes. Since $^{201}Tl$ are used when using antimony sheet and $^{18}F$ and $^{131}I$ have no shielding effect, it is thought that it is effective to reduce dose by repeating training and simulation training so that work can be done in a short time.

Method for Determining Transportation Grade for HIC Containing Spent Resin Using Radioactivity Analysis (방사성페기물 핵종분석 결과를 사용한 폐수지의 운반물등급 분류 방법)

  • Kim, Tae-Wook;Choi, Ki-Seop;Kang, Ki-Doo;Ha, Jong-Hyun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.6 no.1
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    • pp.11-15
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    • 2008
  • In order to transport spent resin in a high integrated container made of high density polyethylene, a method for determining transportation grade by radioactivity analysis was developed. Ratios of radioisotopes in spent resin were derived from radioactivity analysis on spent resin. Associated curie-to-dose factors were determined to estimate radioisotope inventory from surface dose rates of spent resin. From the results, Activity limit of type A package was derived to be 1.19 TBq for HIC, and the corresponding surface dose rate was found to be 124.2 mSv/h.

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Fluoroscopic Radiation Exposure during Percutaneous Kyphoplasty

  • Choi, Hyun-Chul
    • Journal of Korean Neurosurgical Society
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    • v.49 no.1
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    • pp.37-42
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    • 2011
  • Objective: The author measured levels of fluoroscopic radiation exposure to the surgeon's body based on the different beam directions during kyphoplasty. Methods: This is an observational study. A series of 84 patients (96 vertebral bodies) were treated with kyphoplasty over one year. The patients were divided into four groups based on the horizontal and vertical directions of the X-Ray beams. We measured radiation exposure with the seven dosimetry badges which were worn by the surgeon in each group (total of 28 badges). Twenty-four procedures were measured in each group. Cumulative dose and dose rates were compared between groups. Results: Fluoroscopic radiation is received by the operator in real-time for approximately 50% (half) of the operation time. Thyroid protectors and lead aprons can block radiation almost completely. The largest dose was received in the chest irrespective of beam directions. The lowest level of radiation were received when X-ray tube was away from the surgeon and beneath the bed (dose rate of head, neck, chest, abdomen and knee: 0.2986, 0.2828, 0.9711, 0.8977, 0.8168 mSv, respectively). The radiation differences between each group were approximately 2.7-10 folds. Conclusion: When fluoroscopic guided-KP is performed, the X-Ray tube should be positioned on the opposite side of the operator and below the table, otherwise the received radiation to the surgeon's body would be 2.7-10 times higher than such condition.

Uptake efficiencies of PCB 153 in fathead minnows through food chain of sediment-midge-fish

  • Park, Kyungho;Peter G. Meier
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2003.06a
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    • pp.162-165
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    • 2003
  • Uptake efficiencies of PCB 153 in fathead minnow through food chain of sediment-midge-fish were evaluated. Contaminated fish food, the midge Chironomus plumosus was prepared by exposing to sediments with PCB 153. We could harvest the midges with body PCB 153 levels of ∼ 1.0 mg/g and ∼ 10.0 mg/g, respectively, in 2 wk of exposure. PCB 153 level in fish fed with midge of 10.0 mg/g PCB 153 (high-dose group) reached its highest at 11.2 mg/g after 30 d of exposure. However, PCB level in fish fed with midge of 1.0 mg/g PCB 153 (low-dose group) kept increasing following first order rate kinetics until the end of exposure (38 d). When the fish food was changed to the uncontaminated ones, the fish body PCB levels were stabilized in ∼ 3 wk. The uptake efficiency in high-dose fish group was 37%, whereas low-dose group was 55%. Uptake efficiencies in fathead minnows were notably lower than that of pike (∼ 70%). This finding suggests that the uptake efficiency of this PCB congener may depend on the amount of the PCB in diet.

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Decreased Induction of Alcoholic Fatty Liver by YH430 in Rats (YH439의 알콜성 지방간생성 억제작용)

  • 강경애;김영철
    • Toxicological Research
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    • v.11 no.2
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    • pp.267-271
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    • 1995
  • A single large dose of ethanol as well as chronic ethanol consumption produces alcoholic fatty liver in human and experimental animals. We examined the effects of YH439, a potential hepatoprotective agent, on alcoholic fatty liver generation in adult female rats. In rats treated with YH439 (250 mg/kg, po) 4 hr prior to a single dose of ethanol (6 g/kg, po), a significant decrease in hepatic triglyceride accumulation was observed. YH439 also has an inhibitory effect on hepatic triglyceride and cholesterol accumulation induced by repeated ethanol treatments for one week. Because it has been known that induction of alcoholic fatty liver is associated with lipid peroxidation and/or hepatic glutathione depression, the effect of YH439 on these parameters was determined in the livers of rats treated with ethanol. Coadministration with YH439 inhibited MDA formation and gIutathione depression induced by acute or repeated ethanol administration. In order to determine the effect of YH439 on ethanol metabolism in vivo, disappearance of ethanol from blood was measured. In rats treated with a single dose of ethanol (6 g/kg, po), the ethanol concentration in blood reached a peak approximately 120 min following the treatment which declined linearly for 18 hrs. YH439 had no effect on the decline of blood ethanol concentration regardless of the dose of ethanol given to rats. These results in this study suggest that YH439 has an inhibitory effect on fatty liver generation induced by acute or repeated ethanol consumption through a mechanism not directly related to the rate of ethanol metabolism in vivo.

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A Study of Quality Control Environment of Mammography (유방촬영의 화질관리 환경에 대한 고찰)

  • Hwang, In-Sun;Kim, Young-Keun;Joo, Hyung-Yoon
    • Korean Journal of Digital Imaging in Medicine
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    • v.12 no.2
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    • pp.133-138
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    • 2010
  • The purpose of this study was to survey and test quality control of mammography system. The conclusion of this study is as follows ; First, The rate of pass for phantom image test shows that Film-Screen mammography system(F/S) and computed mammography system(CR) is 80%, Indirect digital mammography system(DR) is 100%. Second, The test of exposure dose shows that F/S is 921 mR. CR is 1,140 mR, DR is 474 mR. The grade of this testament is CR > F/S > DR. Third, The test of average glandular dose shows that F/S is 1,336 mGy, CR is 1,635 mGy, DR is 1,26 mGy. The grade of this testament is CR > F/S > DR. Fourth, The testament of resolution shows as follows F/S is 11~13 Lp/mm, CR is 4~5 Lp/mm, and DR is 5~7 Lp/mm(F/S > DR > CR) Fifth, The survey of projection, cassette, development and reading shows that user are indifference.

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Radiation Dose Assessment of ACP Hotcell for Spent Fuel Treatment in Normal Operation & Accident Case (사용후핵연료 처리를 위한 ACP 핫셀의 정상운영 및 사고시 방사선 환경영향평가)

  • 국동학;정원명;구정회;조일제;이은표;유길성
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.3
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    • pp.155-164
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    • 2004
  • Advanced spent fuel Conditioning Process(ACP) project which is under development for efficient spent fuel management has finished process feasibility study and is preparing $\alpha$-${\gamma}$ type hot cell construction for process experimentation. Radiation dose evaluation for the radioactive nuclides were preliminarily performed for normal operation and accident case with the basic concept design report, the meteorological data and the recent site specific data. According to the production and release rate of nuclides, dose evaluations for residents around facility were performed. The evaluation result shows a safe margin for regulation limits and SAR(Safety Analysis Report) limit of IMEF(Irradiated Material Examination Facility) where this facility will be constructed.

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