• Title/Summary/Keyword: dose equivalent

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Acute toxicity test and safety classification for Termitomyces albuminosus containing pharmacologically similar ingredient of Aconitum koreanum (백부자-대체 가능 한약재의 계종버섯에 대한 급성독성시험과 안전성등급화)

  • An, Minji;Park, Yeongchul
    • The Korea Journal of Herbology
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    • v.32 no.4
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    • pp.33-38
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    • 2017
  • Objectives : Termitomyces albuminosus (Berk.) Heim is one of the famous wild edible mushrooms in the southern part of China. It is known that Termitomyces albuminosus, like Aconitum koreanum used in Korean traditional medicine, contains a kind of cerebroside, termitomycesphin, causing a pharmacologic effect on the neuron system. The pharmacologic effect of Termitomyces albuminosus can be used to possibly replace Aconitum koreanum. However, It needs to be certified as safe before it can be used. Here, a single-oral toxicity test and safety classification was conducted to obtain acute information of the toxicity of dried-Termitomyces albuminosus powder and to secure its safety in clinical applications. Methods : In order to calculate approximate lethal dose(ALD), test substance was orally administered to male and female SD-rat at dose levels of 5,000 and 0 (vehicle control) mg/kg (body weight). Based on the result of this toxicity, also the estimation of safety classification was calculated using the HED-based (human equivalent dose) MOS (margin of safety). Results : There were no mortalities, test substances treatment-related clinical signs, no changes in the body or organ weights, and no gross or histopathological findings at 14 days after treatment with test substance. Thus, the approximate lethal dose of dried-Termitomyces albuminosus powder was considered over 5,000 mg/kg in both female and male mice. Conclusions : Based on the limit dose, 5000 mg/kg, it was estimated that dried-Termitomyces albuminosus powder is classified as "Specified class B" indicating that clinical dose is not limited to patients as safe as food.

Comparison of Doses According to Change of Bladder Volume in Treatment of Prostate Cancer (전립선암 치료 시 방광의 용적 변화에 따른 선량의 비교 평가)

  • Kwon, Kyung-Tae;Min, Jung-Whan
    • Journal of radiological science and technology
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    • v.40 no.3
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    • pp.415-421
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    • 2017
  • In the case of radiation therapy for prostate cancer, a balloon infused with a certain amount of air through the anus is used to reduce rectal dose. Because of the reason, radiation therapy for prostate cancer has acquired CBCT for daily image induction. In order to maintain the anatomical structure most similar to the first CT taken before treatment, it is pretreated, but it can not be said to be perfectly consistent. In two actual treatment regimens, the volume of the bladder was measured as 45.82 cc and 63.43 cc, and the equivalent diameter was 4.4 cm and 4.9 cm. As a result of this study, the mean volume of the bladder was estimated to be 56.2 cc, 105.6 cc by 20 CBCT. The mean dose of CBCT was 1.74% and the mean Bladder mean dose was 96.67%. In case B, PTV mean dose was 4.31%, Bladder mean Dose was estimated to be 97.35%. The changes in the volume of the bladder resulted in changes in the dose of PTV and bladder. The correlation coefficient of bladder dose according to the change of bladder volume showed linearity of mean dose $R^2=-0.94$. The correlation coefficient of the PTV dose according to the volume change of the bladder showed linearity of mean dose $R^2=0.04$. It was found that the dose change of PTV was larger than that of bladder according to the change of bladder volume.

Z-Domain Frequency Dependent AC System Equivalent for Electromagnetic Transient Studies (전자기 과도 현상 해석을 위한 Z 영역에서의 주파수 의존 교류시스템 등가)

  • Wang, Yong-P.;Hur, Dong-Y.;Park, Hee-C.;Chung, Hyeng-H.
    • Proceedings of the KIEE Conference
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    • 2001.11b
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    • pp.252-255
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    • 2001
  • Modern power systems are very complex and to model them completly is impractical for electromgnetic transient studies. Therefore areas outside the immediate area of interest must be represented by some form of Frequency Dependent Network Equivalent (FDNE). In this paper a method for developing FDNE is presented and demonstrated. The FDNE is generated by Linearized Least Square fitting the frequency response of a z-domain formulation. The advantage of this approach is that a direct implementation occurs which dose not incur errors due to discretization inherent with implementing a fitting function in the s-domain. The developed FDNE is accurate and efficient.

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A Field Test Assessment on the Extremity Doses of Highly-Exposed Radiation Workers During Maintenance Periods at Nuclear Power Plants in Korea (원전 계획예방정비기간 고피폭 접촉작업에서 방사선작업종사자의 말단선량 평가 현장시험)

  • Kim, Hee-Geun;Kong, Tae-Young
    • Journal of Radiation Protection and Research
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    • v.35 no.2
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    • pp.57-62
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    • 2010
  • Maintenance on the water chamber of steam generator, the change of pressurizer heater, the removal of pressure tube feeder, and so on during outage in nuclear power plants (NPPs) has a likelihood of high radiation exposure to whole body of workers even short time period due to the high radiation exposure rates. In particular, it is expected that hands would receive the highest radiation exposure because of its contact with radiation materials. In this study, field tests on extremity dose assessment of radiation workers for contact works with high radiation exposure were conducted during the maintenance periods in Korean pressurized water reactors (PWRs) and pressurized heavy water reactors (PHWRs). In this field test, radiation workers were required to wear additional TLDs on the back and wrist, and an extremity dosimeter on fingers including a main TLD on the chest, while performing maintenance. As a result, it was found that the equivalent dose for fingers was distributed in the fixed range of deep dose and the equivalent dose for wrists.

The Efficacy of Fluorograb for Paediatric Patients Dose Reduction during Pneumatic Reduction and Voiding Cystourethrography(VCUG) (영.유아의 배뇨성 방광-요도 조영술 및 방사선 공기 주입 정복술시 피폭선량 경감을 위한 fluorograb의 유용성)

  • Kim, Sang-Tae;Choi, Ji-Won
    • The Journal of the Korea Contents Association
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    • v.9 no.12
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    • pp.385-390
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    • 2009
  • The Pneumatic Reduction and VCUG (Voiding Cystourethrography) are commonly used in the paediatric age group. The procedures had a particularly long fluroscopic screening time, despite a successful outcome for paediatric patients. Pneumatic Reduction and VCUG almost invariably requires fluoroscopic guidance which does confer a radiation dose. This article contains suggestions on how the radiation dose to paediatric patients from Pneumatic Reduction and VCUG can be made "as low as reasonably achievable" (ALARA). The aim of our study was eliminated in spot image applying the FluoroGrab, which has function of capturing an image of interest area from the picturing while fluoroscopic procedures. FluoroGrab has clinical value equivalent to the spot image, and is applied to the most recent fluoroscopic procedures. The radiologist and the radiographers should consider new option for decreasing the radiation exposure delivered to paediatric patients by making equipment modifications to the fluoroscopy to optimize radiation exposure reduction techniques. Thus, we propose the FluoroGrab instead of spot exposure for the reduction of patient exposure dose in paediatric, and try to confirm the effect of the mitigating amount of radiation exposure to paediatric patients when pneumatic reduction and VCUG. Fluorograb is the safe and useful method that shows the equivalent level of accuracy to spot exposure, and to minimize the radiation load to paediatric patients are to be the substitute for the spot exposure for Pneumatic Reduction and VCUG.

The Efficacy of Fluorograb for Paediatric Patients Dose Reduction during Pneumatic Reduction and Voiding Cystourethrography (VCUG) (영아/유아의 공기 주입 정복술 및 방사선 배뇨성 방광요도 조영술시 피폭 선량 경감을 위한 FluroGrab의 유용성)

  • Kim, Sang-Tae;Choi, Ji Won;Han, Tae-Jong
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.1167-1172
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    • 2009
  • The Pneumatic Reduction and VCUG (Voiding Cystourethrography) are commonly used in the paediatric age group. The procedures had a particularly long fluroscopic screening time, despite a successful outcome for paediatric patients. Pneumatic Reduction and VCUG almost invariably requires fluoroscopic guidance which does confer a radiation dose. This article contains suggestions on how the radiation dose to paediatric patients from Pneumatic Reduction and VCUG can be made "as low as reasonably achievable" (ALARA). The aim of our study was eliminated in spot image applying the FluoroGrab, which has function of capturing an image of interest area from the picturing while fluoroscopic procedures. FluoroGrab has clinical value equivalent to the spot image, and is applied to the most recent fluoroscopic procedures. The radiologist and the radiographers should consider new option for decreasing the radiation exposure delivered to paediatric patients by making equipment modifications to the fluoroscopy to optimize radiation exposure reduction techniques. Thus, we propose the FluoroGrab instead of spot exposure for the reduction of patient exposure dose in paediatric, and try to confirm the effect of the mitigating amount of radiation exposure to paediatric patients when pneumatic reduction and VCUG. Fluorograb is the safe and useful method that shows the equivalent level of accuracy to spot exposure, and to minimize the radiation load to paediatric patients are to be the substitute for the spot exposure for Pneumatic Reduction and VCUG.

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Neutron Dose Measurements Using TLDs in a 252Cf Neutron Field (252Cf 중성자장에서 열형광선량계(TLD)를 이용한 중성자 방사선량 측정)

  • Chang, Insu;Kim, Sang In;Lee, Jung Il;Kim, Jang Lyurl;Kim, Bong Hwan
    • Journal of Radiation Protection and Research
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    • v.38 no.1
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    • pp.37-43
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    • 2013
  • In case of neutron dose measurement using TLDs (thermo-luminescence dosimeters), because the neutron energy dependence of the TLD is very high, the calibration of the energy response according to the characteristics of the neutron spectrum of workplace is required. In the present study, the ambient dose equivalent rates inside and around the Long-Counter (neutron detector) with narrow and complex inside in the neutron field of $^{252}Cf$ were evaluated. The calibration factors to account for the neutron energy dependence of TLDs were established for both the bare and $D_2O$ modulated $^{252}Cf$ neutron beams, respectively. The values of the TLD's measurement were compared with the computational results of the MCNPX (Monte Carlo N-Particles transport code). When using the two calibration factors of the TLD than a single calibration factor, the measured and the calculated values at the point of verification outside and inside the Long-Counter were in more good agreement. This results show that TLD should be calibrated in the reference neutron field similar to workplace situation.

Investigation of organ dose difference of age phantoms for medical X-ray examinations (X선 촬영 시 연령별 장기선량 차이 연구)

  • Park, Sang-Hyun;Lee, Choon-Sik;Kim, Woo-Ran;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.28 no.1
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    • pp.35-42
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    • 2003
  • Methodology for calculating the organ equivalent doses and the effective doses of pediatric and adult patients undergoing medical X-ray examinations were established. The MIRD-type mathematical phantoms of 4 age groups were constructed with addition of the esophagus to the same phantoms. Two typical examination procedures, chest PA and abdomen AP, were simulated for the pediatric patients as well as the adult as illustrative examples. The results confirmed that patients pick up approximate 0.03 mSv of effective dose from a single chest PA examination, and 0.4 to 1.7 mSv from an abdomen AP examination depending on the ages. For dose calculations where irradiation is made with a limited field, the details of the position, size and shape of the organs and the organ depth from the entrance surface considerably affect the resulting doses. Therefore, it is important to optimize radiation protection by control of X-ray properties and beam examination field. The calculation result, provided in this study, can be used to implement optimization for medical radiation protection.

Dosimetric comparison of volumetric modulated arc therapy with robotic stereotactic radiation therapy in hepatocellular carcinoma

  • Paik, Eun Kyung;Kim, Mi-Sook;Choi, Chul Won;Jang, Won Il;Lee, Sung Hyun;Choi, Sang Hyoun;Kim, Kum Bae;Lee, Dong Han
    • Radiation Oncology Journal
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    • v.33 no.3
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    • pp.233-241
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    • 2015
  • Purpose: To compare volumetric modulated arc therapy of RapidArc with robotic stereotactic body radiation therapy (SBRT) of CyberKnife in the planning and delivery of SBRT for hepatocellular carcinoma (HCC) treatment by analyzing dosimetric parameters. Materials and Methods: Two radiation treatment plans were generated for 29 HCC patients, one using Eclipse for the RapidArc plan and the other using Multiplan for the CyberKnife plan. The prescription dose was 60 Gy in 3 fractions. The dosimetric parameters of planning target volume (PTV) coverage and normal tissue sparing in the RapidArc and the CyberKnife plans were analyzed. Results: The conformity index was $1.05{\pm}0.02$ for the CyberKnife plan, and $1.13{\pm}0.10$ for the RapidArc plan. The homogeneity index was $1.23{\pm}0.01$ for the CyberKnife plan, and $1.10{\pm}0.03$ for the RapidArc plan. For the normal liver, there were significant differences between the two plans in the low-dose regions of $V_1$ and $V_3$. The normalized volumes of $V_{60}$ for the normal liver in the RapidArc plan were drastically increased when the mean dose of the PTVs in RapidArc plan is equivalent to the mean dose of the PTVs in the CyberKnife plan. Conclusion: CyberKnife plans show greater dose conformity, especially in small-sized tumors, while RapidArc plans show good dosimetric distribution of low dose sparing in the normal liver and body.

Antigastritic and Antiulcerative Activities of Water Extracts Derived from Scutellaria baicalensis

  • Cho, So-Yean;Lim, Duk-Yun;Kang, Min-Hee;Yoon, Hye-Ran;Kim, Gun-Hee;Lee, Yong-Soo;Jeong, Choon-Sik
    • Biomolecules & Therapeutics
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    • v.14 no.3
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    • pp.171-177
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    • 2006
  • Gastritis and gastric ulcer were known to be induced by gastic acid, stress, ethanol, Helicobacter pylori and free radical, etc. This study was performed for the development of a new drug or nutraceutical from medicinal plants or natural products with anti-gastritis, anti-ulcerative and gastroprotective activities. The water extract of Scutellaria baicalensis was exhibited potent inhibition in HCl ethanol-induced gastric lesion, acetic acid-induced and Shay ulcers, indicating the effects on gastric lesion and ulcer in rats. The water extract of Scutellaria baicalensis significantly inhibited HCl ethanol-induced gastric lesions at the oral dose of 300, 500 mg/kg. In pylorus ligated rats, the treatments of the water extract from Scutellaria baicalensis showed decrease in the volume of gastric secretion and acid output and increase pH at oral dose of 300, 500 mg/kg. And significantly reduced acetic acid-induced ulcer at the oral dose of 500 mg/kg for 12 days. In this study, we have found that the water extract from Scutellaria baicalensis had significant improvement in acute gastritis and ulcer at the dose of 300, 500 mg/kg and in chronic gastritis and ulcer at the dose of 500 mg/kg. Also we evaluated the antibacterial activity against Helicobacter pylori treated with Scutellaria baicalensis. Scutellaria baicalensis had a equivalent antibacterial activity with ampicilin against H. pylori at the dose of $100\;{\mu}/ml$. In histological examination, the water extract of Scutellaria baicalensis drastically restored gastric damages induced by HCl ethanol solution, pylorus- ligature and acetic acid. Therefore, we may use the water extract from Scutellaria baicalensis as antigastritic and antiulcerative agent for the purpose of the improvement or treatment of gastritis and gastric ulcer.