• Title/Summary/Keyword: effective equivalent dose

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Feasibility of Two Dimensional Ion Chamber Array for a Linac Periodic Quality Assurance (선형가속기의 품질관리를 위한 2차원이온전리함배열의 유용성)

  • Lee, Jeong-Woo;Hong, Se-Mie;Park, Byung-Moon;Kang, Min-Young;Kim, You-Hyun;Suh, Tae-Suk
    • Journal of radiological science and technology
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    • v.31 no.2
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    • pp.183-188
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    • 2008
  • Aim of this study is to investigate the feasibility of 2D ion chamber array as a substitute of the water phantom system in a periodic Linac QA. For the feasibility study, a commercial ion chamber matrix was used as a substitute of the water phantom in the measurement for a routine QA beam properties. The device used in this study was the I'm RT MatriXX (Wellhofer Dosimetrie, Germany). The MatriXX consists of a 1,020 vented ion chamber array, arranged in $24{\times}24\;cm^2$ matrix. Each ion chamber has a volume of $0.08\;cm^3$, spacing of 0.762 cm. We investigated dosimetric parameters such as dose symmetry, energy ($TPR_{20,10}$), and absolute dose for comparing with the water phantom data with a Farmer-type ionization chamber (FC65G, Wellhofer Dosimetrie, Germany). For the MatriXX measurements, we used the white polystyrene phantom (${\rho}:\;1.18\;g/cm^3$) and also considered the intrinsic layer (${\rho}:\;1.06\;g/cm^3$, t: 0.36 cm) of MatriXX to be equivalent to water depth. In the preliminary study of geometrical QA using MatriXX, the rotation axis of collimator and half beam junction test were included and compared with film measurements. Regarding the dosimetrical QA, the MatriXX has shown good agreements within ${\pm}1%$ compared to the water phantom measurements. In the geometrical test, the data from MatriXX were comparable with those from the films. In conclusion, the MatriXX is a good substitute for water phantom system and film measurements. In addition, the results indicate that the MatriXX as a cost-effective novel QA tool to reduce time and personnel power.

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광어(Paralichtys olivaceus)의 스쿠치카감염증(感染症) -스쿠치카섬모충(纖毛蟲)의 배양성상(培養性状).약제감수성(藥劑感受性).병원성(病源性)-

  • 길수 수;일향진일;오 명주;생도삼내자;목촌교구;삼 립성;야촌철일;회면량남
    • Journal of fish pathology
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    • v.6 no.2
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    • pp.205-218
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    • 1993
  • On the development of hirame(Paratichtys olivaceus) culture, outbreak of scuticociliata infection was reported to cause severe damage in Japan. To establish effective measures for isolation and cultivation of this ciliate, we tried to culture this pathogenic ciliate using medium for bacteria and fish cell lines in vitro. Scuticociliata from the brain tissues of infected fish was aseptically inoculated to CHSE-214 cells cultured in MEM-10 without antibiotic. Scuticociliata grew well and the number of ciliate reached $10^6\;cells/ml$ at temperatures of $15^{\circ}C$ to $20^{\circ}C$ for 10d. The number of ciliate cultured in the cell lines is 10 times higher than the numbers cultured in the liquid medium alone. This ciliata could be cloned by dilution method. Scuticociliata isolated could grow well on 42 different cell lines that were established from marine fish, warm freshwater fish, and salmonids. This ciliate could be preserved in liquid nitrogen for more than 6 months. Subsequently, we observed the optimal temperature and salinity for growth, and tested the sensitivities of this organism to formaldehyde, flagyl(Metronidazole), Ekuteshin(Combination compound of sulfamonometoxin and ormethoprim), and ozonixation. Optimal temperature for growth was $25^{\circ}C$ and salinity was 1.0 to 1.5%. Washed scuticociliata was killed by formaldehyde at the concentration of 50ppm for 10min, but was not completely killed even at a high concentration of 400ppm for 20min in MEM-5. Flagyl and Ekuteshin can inhibit the growth of scuticociliata at the concentration of 1,000 and $100{\mu}g/ml$ in MEM-10, respectively. More than 99% of this scuticociliata could be killed by ozonization at a dose equivalent to $1.0mg/\ell$ oxidant for 30sec in sea water. Isolated scuticociliata showed the pathogenicity to the cultured hirame by artificial infection(I. P. injection, $10^5\;cells$/fish). The number of scuticociliata in the water could be counted by most probable number(MPN) method using tissue culture, and the minimum detectable number was $1.8\;cells/\ell$. The number in the reservoir tank for water supply to the culture tank was 110 cells/l. After cleaning by elimination of the sediments from of the reservoir tank and disinfected with formaldehyde, number of scuticociliata decreased and was counted less than $1.8\;cells/\ell$ and infection rate of cultured hirame was decreased.

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Study on Soil Extraction Methods for the Human Health Risk Assessment of Crop Intake Pathway around Abandoned Metal Mine Areas (폐금속광산 지역 농작물섭취경로의 인체위해도 산정을 위한 생물농축계수와 토양분석방법에 관한 연구)

  • Lim, Tae-Yong;Lee, Sang-Woo;Yun, Seong-Taek;Kim, Soon-Oh
    • Journal of Soil and Groundwater Environment
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    • v.21 no.6
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    • pp.56-66
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    • 2016
  • Generally, the contribution of crop-intake pathway (CIP) is remarkable in human health assessment (HHA) of heavy metal contamination. Although the crop exposure concentrations (Cp) should directly be used for calculating the average daily dose (ADD) of CIP, the soil exposure concentration (Cs) multiplied by soil-crop bio-concentration factor (BCF) has frequently been used instead of using Cp values. Thus, the BCF values are significant in the HHA, and care should be taken to ensure the reasonable acquisition of BCF values. Meanwhile, the BCF values are known to be significantly affected by analytical methods. Nevertheless, they have been calculated from the concentrations of soil and crop analyzed by only one method: total digestion (aqua regia extraction). For this reason, this study was initiated to seek appropriate soil analysis methods for effective computation of the ADD of CIP. The concentrations of 5 metal contaminants (As, Cd, Cu, Pb, and Zn) in 127 soil samples obtained from 4 abandoned metal mine areas were analyzed by several methods including total digestion and partial digestions using 0.1/1 N HCl, 1M $NH_4NO_3$, 0.1 M $NaNO_3$, and 0.01M $CaCl_2$. The heavy metal concentrations in 127 crop samples (rice grains) were analyzed by total digestion as well. Using the concentrations of soils and crops, the BCF values of each contaminant were calculated according to the kind of soil extraction methods applied. Finally, the errors between Cp and $C_s{\times}BCF$ were computed to evaluate the relevance of each method. The results indicate that the partial extraction using 0.1 N and 1 N HCl was superior or equivalent to total digestion. In addition, the 0.1M $NaNO_3$ method combined with total digestion is recommended for improving the reliability of BCF values.

Antioxidant Activity and Safety Evaluation of Juice Containing Protaetia brevitarsis (흰점박이꽃무지(Protaetia brevitarsis) 함유 음료의 in vitro 항산화 관련 생리활성효능 및 안전성 검증)

  • Park, Jae-Hee;Kim, So-Yun;Kang, Min-Gu;Yoon, Min-Soo;Lee, Yang-Il;Park, Eun-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.1
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    • pp.41-48
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    • 2012
  • The purpose of this study was to assess the antioxidant activity of vegetable extracts (pumpkin, aloe, and artichoke) containing Protaetia brevitarsis (PB) and the clinical and pathological changes in ICR mice after a single oral administration. The total polyphenol (TP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, total radical trapping antioxidant potential (TRAP), oxygen radical absorbance activity (ORAC), and single cell gel electrophoresis assay were done to measure their antioxidant activities. The effect of vegetable extracts containing PB in TP and the ORAC value was significantly higher than those without PB. In addition, all extracts had effective $DPPH{\cdot}$ scavenging and $ABTS{\cdot}+$ scavenging activities. The protective effect of vegetable extracts with/without PB on $H_2O_2$-induced DNA damage was found. In a single-dose toxicity study, mortality, body weight, physiological signs, and biochemical analysis were analyzed. Seventy mice were randomly assigned to 7 experimental groups and were administered three vegetable extracts with and without PB (2 g/kg). A full 14 days after administration, no mice mortality was observed in any group. Body weight, physiological signs, and biochemical analysis were never significantly different from those of the control group. Taken together, these findings indicate that vegetable extracts containing PB with antioxidant activities and safety could be applied as medicinal and edible resources in an industrial area.

A brief method for preparation of gintonin-enriched fraction from ginseng

  • Choi, Sun-Hye;Jung, Seok-Won;Kim, Hyun-Sook;Kim, Hyeon-Joong;Lee, Byung-Hwan;Kim, Joon Yong;Kim, Jung-Hyun;Hwang, Sung Hee;Rhim, Hyewon;Kim, Hyoung-Chun;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.39 no.4
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    • pp.398-405
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    • 2015
  • Background: Ginseng has been used as a tonic for invigoration of the human body. In a previous report, we identified a novel candidate responsible for the tonic role of ginseng, designated gintonin. Gintonin induces $[Ca^{2+}]_i$ transient in animal cells via lysophosphatidic acid receptor activation. Gintonin-mediated $[Ca^{2+}]_i$ transient is linked to anti-Alzheimer's activity in transgenic Alzheimer's disease animal model. The previous method for gintonin preparation included multiple steps. The aim of this study is to develop a simple method of gintonin fraction with a high yield. Methods: We developed a brief method to obtain gintonin using ethanol and water. We extracted ginseng with fermentation ethanol and fractionated the extract with water to obtain water-soluble and water-insoluble fractions. The water-insoluble precipitate, rather than the water-soluble supernatant, induced a large $[Ca^{2+}]_i$ transient in primary astrocytes. We designated this fraction as gintonin-enriched fraction (GEF). Results: The yield of GEF was approximately 6-fold higher than that obtained in the previous gintonin preparation method. The apparent molecular weight of GEF, determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was equivalent to that obtained in the previous gintonin preparation method. GEF induced $[Ca^{2+}]_i$ transient in cortical astrocytes. The effective dose (ED50) was $0.3{\pm}0.09{\mu}g/mL$. GEF used the same signal transduction pathway as gintonin during $[Ca^{2+}]_i$ transient induction in mouse cortical astrocytes. Conclusion: Because GEF can be prepared through water precipitation of ginseng ethanol extract and is easily reproducible with high yield, it could be commercially utilized for the development of gintoninderived functional health food and natural medicine.

Hypofractionated intensity-modulated radiotherapy in patients with localized prostate cancer: a preliminary study

  • Kang, Hye Jin;Kay, Chul-Seung;Son, Seok Hyun;Kim, Myungsoo;Jo, In Young;Lee, So Jung;Lee, Dong Hwan;Suh, Hong Jin;Choi, Yong Sun
    • Radiation Oncology Journal
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    • v.34 no.1
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    • pp.45-51
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    • 2016
  • Purpose: The aim of this work was to assess the efficacy and tolerability of hypofractionated intensity-modulated radiotherapy (IMRT) in patients with localized prostate cancer. Materials and Methods: Thirty-nine patients who received radical hypofractionated IMRT were retrospectively reviewed. Based on a pelvic lymph node involvement risk of 15% as the cutoff value, we decided whether to deliver treatment prostate and seminal vesicle only radiotherapy (PORT) or whole pelvis radiotherapy (WPRT). Sixteen patients (41%) received PORT with prostate receiving 45 Gy in 4.5 Gy per fraction in 2 weeks and the other 23 patients (59%) received WPRT with the prostate receiving 72 Gy in 2.4 Gy per fraction in 6 weeks. The median equivalent dose in 2 Gy fractions to the prostate was 79.9 Gy based on the assumption that the ${\alpha}/{\beta}$ ratio is 1.5 Gy. Results: The median follow-up time was 38 months (range, 4 to 101 months). The 3-year biochemical failure-free survival rate was 88.2%. The 3-year clinical failure-free and overall survival rates were 94.5% and 96.3%, respectively. The rates of grade 2 acute genitourinary (GU) and gastrointestinal (GI) toxicities were 20.5% and 12.8%, respectively. None of the patients experienced grade ${\geq}3$ acute GU and GI toxicities. The grade 2-3 late GU and GI toxicities were found in 8.1% and 5.4% of patients, respectively. No fatal late toxicity was observed. Conclusion: Favorable biochemical control with low rates of toxicity was observed after hypofractionated IMRT, suggesting that our radiotherapy schedule can be an effective treatment option in the treatment of localized prostate cancer.

A Study on Developing Customized Bolus using 3D Printers (3D 프린터를 이용한 Customized Bolus 제작에 관한 연구)

  • Jung, Sang Min;Yang, Jin Ho;Lee, Seung Hyun;Kim, Jin Uk;Yeom, Du Seok
    • The Journal of Korean Society for Radiation Therapy
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    • v.27 no.1
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    • pp.61-71
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    • 2015
  • Purpose : 3D Printers are used to create three-dimensional models based on blueprints. Based on this characteristic, it is feasible to develop a bolus that can minimize the air gap between skin and bolus in radiotherapy. This study aims to compare and analyze air gap and target dose at the branded 1 cm bolus with the developed customized bolus using 3D printers. Materials and Methods : RANDO phantom with a protruded tumor was used to procure images using CT simulator. CT DICOM file was transferred into the STL file, equivalent to 3D printers. Using this, customized bolus molding box (maintaining the 1 cm width) was created by processing 3D printers, and paraffin was melted to develop the customized bolus. The air gap of customized bolus and the branded 1 cm bolus was checked, and the differences in air gap was used to compare $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$ and $V_{95%}$ in treatment plan through Eclipse. Results : Customized bolus production period took about 3 days. The total volume of air gap was average $3.9cm^3$ at the customized bolus. And it was average $29.6cm^3$ at the branded 1 cm bolus. The customized bolus developed by the 3D printer was more useful in minimizing the air gap than the branded 1 cm bolus. In the 6 MV photon, at the customized bolus, $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of GTV were 102.8%, 88.1%, 99.1%, 95.0%, 94.4% and the $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of branded 1cm bolus were 101.4%, 92.0%, 98.2%, 95.2%, 95.7%, respectively. In the proton, at the customized bolus, $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of GTV were 104.1%, 84.0%, 101.2%, 95.1%, 99.8% and the $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of branded 1cm bolus were 104.8%, 87.9%, 101.5%, 94.9%, 99.9%, respectively. Thus, in treatment plan, there was no significant difference between the customized bolus and 1 cm bolus. However, the normal tissue nearby the GTV showed relatively lower radiation dose. Conclusion : The customized bolus developed by 3D printers was effective in minimizing the air gap, especially when it is used against the treatment area with irregular surface. However, the air gap between branded bolus and skin was not enough to cause a change in target dose. On the other hand, in the chest wall could confirm that dose decrease for small the air gap. Customized bolus production period took about 3 days and the development cost was quite expensive. Therefore, the commercialization of customized bolus developed by 3D printers requires low-cost 3D printer materials, adequate for the use of bolus.

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Antioxidant Activities of Dianthus chinensis L. Extract and Its Inhibitory Activities against Nitric Oxide Production and Cancer Cell Growth and Adhesion (패랭이꽃 추출물의 항산화, Nitric Oxide 생성저해, 암세포 성장 및 부착 억제 활성)

  • Lee, Jungjae;Seo, Younggeo;Lee, Junho;Ju, Jihyeung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.1
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    • pp.44-51
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    • 2016
  • The aim of the study was to investigate the antioxidant content and activities of ethanol extract of the edible flower Dianthus chinensis L. (DCE) as well as its inhibitory activities against nitric oxide (NO) production in macrophages and growth and adhesion of human cancer cells. The total polyphenol, flavonoid, and carotenoid levels of DCE were 19.0 mg gallic acid equivalent/g, 65.7 mg quercetin equivalent/g, and $95.0{\mu}g/g$, respectively. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and ferric reducing antioxidant power of DCE at a concentration of $1,000{\mu}g/mL$ were 44% and 51%, respectively. In lipopolysaccharide-treated RAW 264.7 macrophages, treatment with DCE at concentrations of 500 and $1,000{\mu}g/mL$ resulted in significantly reduced NO levels (to 7~23% of the control). In H1299 human lung carcinoma cells and HCT116 human colorectal carcinoma cells, treatment with DCE at concentrations of 250, 500, and $1,000{\mu}g/mL$ resulted in dose-dependent growth inhibition. DCE was also effective in inhibiting adhesion of both H1299 cells (to 55% of the control at concentration of $1,000{\mu}g/mL$) and HCT116 (to 26~40% of the control at concentrations of 250, 500, and $1,000{\mu}g/mL$). These results suggest that DCE exerts antioxidant, anti-inflammatory, and anti-cancer activities in vitro.

Efficacy of a Protective Grass Shield in Reduction of Radiation Exposure Dose During Interventional Radiology (방사선학적 중재적 시술시 납유리의 방사선 방어효과에 관한 연구)

  • Jang, Young-Ill;Song, Jong-Nam;Kim, Young-Jae
    • Journal of the Korean Society of Radiology
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    • v.5 no.5
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    • pp.303-308
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    • 2011
  • Background/Aims : The increasing use of diagnostic and therapeutic interventional radiology calls for greater consideration of radiation exposure risk to radiologist and radiological technician, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a protective grass shield. Methods : A protective grass was following data depth, 0.8 cm; width, 100 cm; length, 100 cm, lead equivalent, 1.6 mmPb. The protective shield was located between the patient and the radiologist. Thirty patients (13 male and 17 female) undergoing interventional radiology between September 2010 and December 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective grass shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. Results : The mean patient age was 69 years. The mean patient height and weight was $159.7{\pm}6.7$ cm and $60.3{\pm}5.9$ kg, respectively. The mean body mass index (BMI) was $20.5{\pm}3.0$ kg/m2. radiologists received $1530.2{\pm}550.0$ mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to $50.3{\pm}85.2$ mR/hr with the protective lead shield (p-value<0.0001). The radiation exposure to radiologist and radiological technician was significantly reduced by the use of a protective lead shield (p value <0.0001). The amount of radiation exposure during interventional radiology was related to the patient' BMI (r=0.749, p=0.001). Conclusions : This protective shield grass is effective in protecting radiologist and radiological technician from radiation exposure.

Some Characteristics of Teflon-Thermoluminescent Dosimeters (테프론 열형광선량계(熱螢光線量計)의 특성(特性))

  • Lee, Soo-Yong
    • Journal of Radiation Protection and Research
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    • v.7 no.1
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    • pp.23-33
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    • 1982
  • The characteristic thermoluminescence responses of Teflon thermoluminescent dosimeters to radiations have been studied by the variation of radiation qualities as well as the high dose radiations. The change in the sensitivity of TLDs for different radiation qualities were studied through not only the photon energy dependence but also the change of supralinearity on the photon energy dependence, by exposing $^{60}Co$ gamma rays, the effective X-rays of 44keV, 69keV, 108keV, and thermal neutron of 0.04 eV. The results were as the following: The TL response of $T-CaSO_4$: Dy as a function of absorbed dose was linear up to about 5 Gy, and the response beyond 5Gy was supralinear for $^{60}Co$ gamma rays. The supralinearity of T-LiF-7 became noticeably apparent more than that of $T-CaSO_4$:Dy and also the lower the LET of radiation became the higher the supralinear effects were. No supralinearity appeared for the thermal neutron irradiations equivalent to 10Gy of $^{60}Co$ gamma rays. The relative sensitivities (Rs), which depended on the doses of $^{60}Co$ gamma rays to the TLDs of T-LiF-7 and T-$CaSO_4$:Dy could be, respectively, approximated to the following empirical formula fitted by the least square method: $$R_{LiF}=1.021-0.04581\;logD+0.402(logD)^2-0.405(logD)^3,\;\;5{\times}10^3{\geq}D{\geq}1(Gy)$$ $$R_{CaSO_4}=0.976-0.3241\;logD+0.262(logD)^2-0.298(logD)^3,\;5{\times}10^3{\geq}D{\geq}1(Gy)$$.

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