• 제목/요약/키워드: IR radiation

검색결과 361건 처리시간 0.026초

Dose Comparison of Treatment Plans Using Different Ir-192 Sources and Treatment Planning Systems for Intracavitary HDR Brachytherapy (고선량률 강내 근접치료에 사용되는 Ir-192 선원과 치료계획 시스템간의 계산선량 비교)

  • Park, Dong-Wook;Kim, Young-Seok;Park, Sung-Ho;Choi, Eun-Kyung;Kim, Jong-Hoon;Lee, Sang-Wook;Song, Si-Yeol;Ahn, Seung-Do;Noh, Young-Joo
    • Progress in Medical Physics
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    • 제20권1호
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    • pp.1-6
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    • 2009
  • For HDR intracavitary brachytherapy with ovoids and a tandem, we compared the dose discrepancy of treatment plans using two different Ir-192 sources (microSelectron, Varian) and generated on two different treatment planning systems (PLATO, BrachyVision). The treatment plans of ten patient treated from Oct. 2007 to Jan. 2008 were selected for these comparisons. For the comparison of dose calculation using different sources, the average discrepancies were $-0.91{\pm}0.09%$, $-0.27{\pm}0.07%$, $0.22{\pm}0.39%$, and $0.88{\pm}0.37%$ in total treatment time and at B-point and ICRU bladder and rectum reference point, respectively. Comparing the two systems, the average dose discrepancies between treatment planning programs were $-0.22{\pm}0.42%$, $-0.25{\pm}0.29%$, $-0.23{\pm}0.63%$, and $-0.17{\pm}0.76%$, and the average dose discrepancies between positioning methods (PLATO with film and BrachyVision with digitial image) were $-0.61{\pm}0.59%$, $-0.77{\pm}0.45%$, $-0.72{\pm}1.70%$, and $0.35{\pm}2.82%$ at A-point, B-point, and ICRU bladder and rectum reference points, respectively. The rectal dose discrepancies between two systems were reached 5.87%. The difference in the dwell position expected by each TPS are mainly affected by the differences in the positioning method in TPSs and have an effect on dose calculations of rectal and bladder located in AP direction.

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Inhibition of $\gamma$-Irradiation Induced Adhesion Molecules and NO Production by Alginate in Human Endothelial Cells

  • Son, Eun-Wha;Cho, Chul-Koo;Rhee, Dong-Kwon;Pyo, Suhk-Neung
    • Archives of Pharmacal Research
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    • 제24권5호
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    • pp.466-471
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    • 2001
  • Inflammation is a frequent radiation-induced reaction following therapeutic irradiation. Treatment of human umbilical endothelial cells (HUVEC) with $\gamma$-irradiation ($\gamma$IR) induces the expression of adhesion proteins such as intercellular adhesion molecule-1 (VCAM-1 ), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Since the upregulation of these proteins on endothelial cell surface has been known to be associated with inflammation, interioring with the expression of adhesion molecules is an important therapeutic target. In the present study, we demonstrate that high mannronic acid-containing alginate (HMA) inhibits $\gamma$IR induced expression of ICAM-1, VCAM-1, and E-selectin on HUVEC in a dose dependent manner. HMA also inhibited $\gamma$IR induced production of Nitric oxide (NO). These data suggest that HMA has therapeutic potential for the treatment of various inflammatory disorder associated with an increase of endothelial leukocyte adhesion molecules.

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A Study on the protection of false alarm in the UV/IR flame detector (불꽃 감지기에서 오동작 방지에 관한 연구)

  • Lim, Byung-Hyun;Park, Sung-Jin;Lim, Jong-Yeon;Hwang, Jong-Sun;Kim, Young-Min
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.209-212
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    • 2001
  • A flame detector responds either to radiant energy visible to the human eye or outside the range of human vision. Such a detector is sensitive to glowing embers, coals, or flames which radiate energy of sufficient intensity and spectral quality to actuate the alarm. An infra-red detectors can respond to the total IR component of the flame alone or in combination with flame flicker in the frequency range of 5 to 30 Hz. A major problem in the use of infrared detectors receiving total IR radiation is the possible interference of solar radiation in the infrared region. When detectors are located in places shielded from the sun, such as vaults, filtering or shielding the unit from the sun's rays is unnecessary. In this study, we proposed method for redue a false alarm with using filtering & sensor technology for distinguish of causes of raise a false alarm and pure flame.

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Optimization of sintering process of the far-infrared radiation ceramic (원적외선 방사 세라믹의 소결공정 최적화)

  • Park, Jae Hwa;Kim, Hyun Mi;Kang, Hyo Sang;Choi, Jae Sang;Choi, Bong Geun;Nam, Ki Woong;Nam, Han Woo;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • 제26권1호
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    • pp.28-34
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    • 2016
  • Far-infrared radiation ceramic is an attractive material that provides thermal therapy by permeating the infrared rays into the deep inside of the human skin. Therefore, it is currently used for thermal therapy devices, thermal mat, heating equipment and so on. This work aims to optimize the sintering process of the far-infrared radiation ceramic with the process parameters of temperature and time. A variety of characterization tools have been used to investigate the optimal sintering condition of far-infrared radiation. The phase of far-infrared radiation ceramic was characterized by using X-ray diffraction (XRD) and microstructure of fracture surface was studied by scanning electron microscopy (SEM). The FT-IR was also performed to measure the far-infrared emissivity.

Cell Survival and Expression of Superoxide Dismutase and Catalase Genes in Saccharomyces cerevisiae Treated with N-acetyl-L-cysteine and Ionizing Radiation (Saccharomyces cerevisiae에서 이온화 방사선과 N-acetyl-L-cysteine 처리에 따른 세포 생존과 Superoxide Dismutase와 Catalase 유전자 발현)

  • Park, Ji-Young;Baek, Dong-Won;Nili, Mohammad;Kim, Jin-Kyu
    • Korean Journal of Environmental Biology
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    • 제29권1호
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    • pp.61-67
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    • 2011
  • N-acetyl-L-cysteine (NAC) having a thiol, a precursor for glutathione (GSH), is known as one of the antioxidants. NAC used as a radioprotector against ionizing radiation (IR)-induced injury and damage. The aim of this study was to evaluate the radioprotective effects of NAC against IR-induced cell damage in Saccharomyces cerevisiae and the antioxidative effect of NAC on transcriptional level of yeast antioxidant enzyme genes such as superoxide dismutase (SOD) and catalase. In the present study, yeast cells were pretreated with various concentrations of NAC and/or irradiated with various doses of gamma rays. The cell viability was measured by counting the cell forming unit (CFU). The quantitative real-time PCR was performed for analysis of gene expression of SOD and catalase. The viability of irradiated cells was not improved by pretreatment with NAC. Ionizing radiation with 100 Gy highly induced the gene expression of antioxidant enzymes. In the irradiated group with NAC pretreatment, the gene expression of SOD and catalase was gradually reduced with the increased concentrations of NAC. These results indicate that NAC can act as a useful antioxidant to scavenge reactive oxygen species in vivo, but does not protect cells against IR-induced cell death in S. cerevisiae.

Ir-192 Brachytherapy Planning of Brain Tumor (Ir-192 방사성소선원에 의한 뇌종양의 치료계획)

  • Choi Tae Jin;Park Jeong Ho;Kim Ok Bae;Suh Soo Ji
    • Radiation Oncology Journal
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    • 제6권2호
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    • pp.277-281
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    • 1988
  • Although widely used in external beam treatment planning, computed tomography scans are infrequent in incranial tumors by implanting of Radioactive isotope. This incranial brachytherapy has only become possible by using CT scans and stereotaxic operation methods. The coincidence of single source and tumor axes in brachytherapy is very important to determine the therapeutic dosages. Eventhough using the CT scan, according to spatial location of tumor tying, the section of tumor will be seen enlargement, cause the tumor will be cut off with slight angle to its axes. Correct analysis of tumor size from source is required for rotated axes in analytical geometry.

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Studies on the Zr-Pyrithione Complex (지르코늄-피리치온 착물에 관한 연구)

  • Kwon, Chung-Moo;Rhee, Gye-Ju
    • Journal of Pharmaceutical Investigation
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    • 제20권3호
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    • pp.145-152
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    • 1990
  • Zirconium pyrithione complex was prepared by reaction of sodium-pyrithione solution and zirconyl chloride solution. The physico-chemical properties of the complex was examined by means of IR, XRD, DSC and NMR. And the stability of Zr-complex was investigated on the basis of accelerated stability analysis under conditions of temp. elevation, UV radiation and pH dependence. The result indicates that the ratio of the ligand to metal in Zr-pyrithione complex was determined 4:1, and its stability constant was $4.643{\times}10^4$. The rate order of decomposition of the complex was apparent first-order reaction of which rate constant and the decomposition rate was not only accelerated by effect of heat and UV radiation but was catalyzed by specific acid-base catalysis considered the pH dependence for the hydrolysis of the complex and the suspension was most stable over the range pH 4-8 indicating that solvent catalysis is the primary made of reaction in this region.

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INFLUENCE OF AERIAL FIRE FIGHTING ON INTENSITY OF RADIATION FROM FIRE

  • Iwata, Yusaku;Koseki, Hiroshi;Kon, Fumio
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.269-274
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    • 1997
  • A large scale fire experiment was conducted through the collaboration between the Tokyo Fire Department and the National Research Institute of Fire and Disaster (NRIFD) for the purpose of studying the effectiveness of aerial fro fighting against urban fire. Ten model houses and ten collapsed model houses were arranged in an area of about $2,000\;m^2$. Water was dropped totally fourteen times by helicopters onto the model houses. In order to know influence of water drop, radiation was measured by four radiometers and four IR (Infrared) cameras, which were set around the burning area. In this report, the influence of aerial Ore fighting on fire was discussed in terms of irradiance and IR images. Data of irradiance, flame temperature and flame area showed that influence of each water drop continued only at most a minute.

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Radiation Effects on the Power MOSFET for Space Applications

  • Lho, Young-Hwan;Kim, Ki-Yup
    • ETRI Journal
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    • 제27권4호
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    • pp.449-452
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    • 2005
  • The electrical characteristics of solid state devices such as the bipolar junction transistor (BJT), metal-oxide semiconductor field-effect transistor (MOSFET), and other active devices are altered by impinging photon radiation and temperature in the space environment. In this paper, the threshold voltage, the breakdown voltage, and the on-resistance for two kinds of MOSFETs (200 V and 100 V of $V_{DSS}$) are tested for ${\gamma}-irradiation$ and compared with the electrical specifications under the pre- and post-irradiation low dose rates of 4.97 and 9.55 rad/s as well as at a maximum total dose of 30 krad. In our experiment, the ${\gamma}-radiation$ facility using a low dose, available at Korea Atomic Energy Research Institute (KAERI), has been applied on two commercially available International Rectifier (IR) products, IRFP250 and IRF540.

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[6]-Gingerol Attenuates Radiation-induced Cytotoxicity and Oxidative Stress in HepG2 Cells

  • Chung, Dong-Min;Uddin, S.M. Nasir;Kim, Jin Kyu
    • Korean Journal of Environmental Biology
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    • 제31권4호
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    • pp.376-382
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    • 2013
  • [6]-Gingerol, a major polyphenol of ginger (Zingiber officinale), exhibits a variety of biological properties including anti-oxidant, anti-inflammatory and anti-cancer activity. However, the radioprotective effect of [6]-gingerol is still unknown. The aim of this study was to investigate the radioprotective effect of [6]-gingerol against radiation-induced cell cytotoxicity and oxidative stress in HepG2 cells. [6]-Gingerol pretreatment attenuated radiation-induced cell cytotoxicity caused by 5Gy (half lethal dose, $LD_{50}$ of HepG2 cells). The measurements of superoxide dismutase (SOD) and catalase (CAT) activity were also performed. The results showed that [6]-gingerol pretreatment reduced increasing SOD and CAT activity after exposure of IR, indicating that [6]-gingerol protected oxidative stress by regulating cellular antioxidant enzyme (SOD and CAT) activity. These findings suggest that [6]-gingerol acts as a radioprotector by attenuating cell cytotoxicity and oxidative stress.