• Title/Summary/Keyword: Dose Rate

Search Result 3,201, Processing Time 0.031 seconds

Dose-Rates Evaluation on a Reinforced Hot Cell facility (핫셀시설의 방사선 안전성 평가)

  • 조일제;국동학;구정회;정원명;유길성;이은표;박성원
    • Proceedings of the Korean Radioactive Waste Society Conference
    • /
    • 2003.11a
    • /
    • pp.584-589
    • /
    • 2003
  • The hot cell facility which is designed to permit safe handling of source materials with radioactivity levels up to 1,385 TBq, is planned to be built. To meet this goal, the facility is designed to keep gamma and neutron radiation lower than the recommended dose-rate in normally occupied areas. The calculations performed with QAD-CGGP and MCNP-4C are used to evaluate the proposed engineering design concepts that would provide acceptable dose-rates during a normal operation in hot cell facility. The maximum effective gamma dose-rates on the surfaces of the facility at operation area and at service area calculated by QAD-CGGP are estimated to be $2.10{\times}10^{-3}$, $2.97{\times}10^{-2}$ and $1.01{\times}10^{-1}$ mSv/h, respectively. And those calculated by MCNP-4C are $1.60{\times}10^{-3}$, $2.99{\times}10^{-3}$ and $7.88{\times}10^{-2}$ mSv/h, respectively The dose-rates contributed by neutrons are one order of magnitude less than that of gamma sources, and penetration and toboggan will be partly reinforced by lead shield.

  • PDF

Magnetic resonance image-based tomotherapy planning for prostate cancer

  • Jung, Sang Hoon;Kim, Jinsung;Chung, Yoonsun;Keserci, Bilgin;Pyo, Hongryull;Park, Hee Chul;Park, Won
    • Radiation Oncology Journal
    • /
    • v.38 no.1
    • /
    • pp.52-59
    • /
    • 2020
  • Purpose: To evaluate and compare the feasibilities of magnetic resonance (MR) image-based planning using synthetic computed tomography (sCT) versus CT (pCT)-based planning in helical tomotherapy for prostate cancer. Materials and Methods: A retrospective evaluation was performed in 16 patients with prostate cancer who had been treated with helical tomotherapy. MR images were acquired using a dedicated therapy sequence; sCT images were generated using magnetic resonance for calculating attenuation (MRCAT). The three-dimensional dose distribution according to sCT was recalculated using a previously optimized plan and was compared with the doses calculated using pCT. Results: The mean planning target volume doses calculated by sCT and pCT differed by 0.65% ± 1.11% (p = 0.03). Three-dimensional gamma analysis at a 2%/2 mm dose difference/distance to agreement yielded a pass rate of 0.976 (range, 0.658 to 0.986). Conclusion: The dose distribution results obtained using tomotherapy from MR-only simulations were in good agreement with the dose distribution results from simulation CT, with mean dose differences of less than 1% for target volume and normal organs in patients with prostate cancer.

Immunobiological Studies on Beta-Carotene (베타-카로틴의 면역생물학적 연구)

  • Ahn, Young-Keun;Koo, Ja-Don;Kim, Joung-Hoon;Kim, Bong-Hee;Cho, Phil-Hyoung;Koo, Kyo-Im
    • YAKHAK HOEJI
    • /
    • v.36 no.5
    • /
    • pp.412-426
    • /
    • 1992
  • Effects of beta-carotene on the immunobiological responses were studied in ICR mice. ICR male mice were divided into 8 groups (10 mice/group), and beta-carotene at doses of 4, 20 and 100 mg/kg were orally administered to ICR mice once daily for 28 consecutive days. Cyclophosphamide (CY) was injected intraperitoneally (i.p.) to ICR mice with a single dose of 5 mg/kg body weight at 2 days before secondary immunization. Mice were sensitized and challenged with sheep red blood cells (5-RBC). Immune responses were evaluated by humoral immunity, cellular immunity and non-specific immunity. The results of this study were summarized as follows: (1) Beta-carotene significantly increased the weight ratios of liver, spleen and thymus to body weight depending on dose, and significantly increased the increasing rate of body weight and the number of circulating leukocyte. (2) Beta-carotene dose-dependently increased hemagglutination titer, Arthus reaction and hemolytic plaque forming cell related to humoral immunity. (3) Beta-carotene significantly increased delayed-type hypersensitivity reaction and rosette forming cell related to cellular immunity. (4) Beta-carotene dose-dependently increased phagocytic activity, and significantly increased natural killer (NK) cell activity. (5) Beta-carotene dose-dependently inhibited reductions in humoral immunity, cellular immunity, NK cell activity and phagocytic activity by treatment with CY.

  • PDF

Assessment of Thyroid Dose Evaluation Method by Monitoring of I-131 Concentration in Air (공기중 I-131 농도 감시에 의한 갑상선 피폭 평가법의 적용성)

  • Lee, Jong-Il;Seo, Kyung-Won
    • Journal of Radiation Protection and Research
    • /
    • v.19 no.1
    • /
    • pp.69-80
    • /
    • 1994
  • The TCMI(Three-Compartment Model for iodine) computer code has been developed, which is based on the three-compartment model and the respiratory model recommended in ICRP publication 54. This code is able to evaluate the thyroid burden, dose equivalent, committed dose equivalent and urinary excretion rate as time-dependent functions from the input data: working time and the radioiodine concentration in air. Using the TCMI code, the time-dependent thyroid burdens, the thyroid doses and the urinary excretion rates were calculated for three specific exposure patterns : acute, chronic and periodic. Applicability as an internal dose evaluation method has been assessed by comparing the results with some operational experiences. Simple equations and tables are provided to be used in the evaluation of the thyroid burden and the resulting doses for given I-131 concentration in air and the working time.

  • PDF

Effect of Oral Administration of Red ginseng acidic polysaccharide (RGAP) on the Tumor Growth Inhibition (홍삼산성다당체 (RGAP)의 경구투여에 의한 항종양 효과)

  • Kwak, Yi-Seong;Shin, Han-Jae;Song, Yong-Bum;Kyung, Jong-Soo;Wee, Jae-Joon;Park, Jong-Dae
    • Journal of Ginseng Research
    • /
    • v.29 no.4
    • /
    • pp.176-181
    • /
    • 2005
  • Our previous reports demonstrated that ip. administration of Korean red ginseng acidic polysaccharide (RGAP) exerts antitumor activity In mice. The present study was carried out to compare the effects of ip. and p.o. routes of administration of RGAP on either normal or tumor-bearing BALB/c mice. RGAP was administered either ip. or p.o. at doses of 100, 300, 500, 1000 mg/kg for 1 or 5 weeks. Peritoneal macrophages from mice treated with RGAP p.o. at a dose of 300 mg/kg either for 1 or 5 weeks did not exhibit growth inhibition activity toward WEHI-I64 tumor cells. However, administration of RGAP at a dose of 600 mg/kg for both 1 and 5 weeks increased the antitumor activity of macrophages. Oral administration of RGAP (600 mg/kg) for 5 weeks and ip. administration of RGAP (300 mg/kg) for 1 week resulted in antitumor activities of $40\%$ and $45\%$, respectively, indicating that the effect of i.p. injection is more potent 2 and 5 times than that of p.o. one in terms of dose and duration, respectively. Tumor inhibition rates of RGAP at doses of 300, 500, 1000 mg/kg in mice transplanted with B16-F10 melanoma were 4.4, 12.0, and $45.4\%$, respectively, meaning that p.o. dose higher than 500 mg/kg possess marked antitumor activity. The results above suggests that p.o. administration of RGAP also show antitumor activity in vivo depending on the dose.

AN ELECTRON MICROSCOPIC STUDY ON THE COBALT-60 IRRADIATION EFFECTS ON THE SALIVARY GLAND OF THE WHITE RAT (Cobalt-60 방사선조사가 백서의 타액선에 미치는 영향에 관한 전자현미경적 연구)

  • Park Chang Seo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
    • /
    • v.15 no.1
    • /
    • pp.27-40
    • /
    • 1985
  • This study was undertaken to observe the histopathologic changes in salivary gland of the white rats when exposed to megavoltage fractionated dose of cobalt-60 irradiation and 78 female white rats, weighing approximately 180gm, were divided into control and 3 experimental groups. Irradiation on experimental groups was delivered by using 6000 curies MeV ALCYON cobalt-60 teletherapy unit with exposure rate 183 rads per minute, in source skin distance 80cm, 600 rads every 3 days. In experimental groups, Group Ⅰwas irradiated of total dose 1200 rads for a period of 6 days, Group Ⅱ was irradiated of total dose 2400 rads for a period of 12 days and Group Ⅲ was irradiated of total dose of 4800 rads for a period of 24 days. The animals were sacrificed serially at 3 hours, 6 hours, 10 hours, 1st day, 4th day, 7th day after each completion of irradiation exposure. At sacrifice, salivary glands were excised and examined microscopically and electromicroscopically. The results were as follows: 1. The acinar cells of parotid and submaxillary gland showed damage varied with dose, 1200 rads resulted in very mild injury while 4800 rads caused most extensive injury. 2. The acinar cells of parotid and submandibular gland showed similar ultrastructural alterations, appeared as pleomorphic nucleus, decreased numbers and pleomorphism of secretory granules, distention of rough endplasmic reticulum, expansion and pallor appearance of mitochondria, and hypertrophy of Golgi complex. 3. Parotid serous cells were the most sensitive components, displaying morphological alterations of radiation damage as early as 3 hours, followed by submandibular seromucinous cells and secretory tubular cells. 4. The mucous cells of sublingual gland, as well as the whole ductal lining cells of each salivary gland, displayed no significant alterations. No evidence of microvascular injury through whole experimental groups indicated that microvascular impairment does not contribute to early salivary gland injury.

  • PDF

Effects of the Scattered Radiation on Image Quality and Exposure Dose in Chest Radiography (흉부X선촬영시(胸部X線撮影時) 산란선(散亂線)이 화질(畵質)과 피폭선량(被曝線量)에 미치는 영향(影響))

  • Iino, Yu;Hayashi, Taro;Ishida, Yuji;Maeda, Mika;Sakurai, Tatsua;Lee, Man-Koo;An, Bong-Sun;Kim, Jung-Min
    • Journal of radiological science and technology
    • /
    • v.16 no.2
    • /
    • pp.27-38
    • /
    • 1993
  • To investigate relationships between image guality and exposure dose, Chest X-ray films were evaluated for the following points:how much scattered radiation can affect reduction in image quality and can be permissible diagnostically? For this purpose using a test charts and Burger's phantoms. The visual evaluation of their X-ray films and the measurements of scattered radiation were carried out. The dose of scattered radiation ranging from 20 to 25% was found to be for nothing in any diagnostic obstacle. In this range, surface doses were low of 17, 21, and $25{\mu}Gy$ for The thickness of the chest of 15, 20 and 25 cm respectively. Comparison of these high voltage X-ray films with low voltage ones showed a surface dose rate of 1:11.7. Therefore, X-ray quality, photosensitive materials(film and screen) and grid should be selected very carefully for the purpose of reduction in exposure dose.

  • PDF

Measurement and Analysis of X-ray Absorbed Dose in Water Phantom using TLD (TLD를 이용한 X-선 수중 흡수선량 측정 및 해석)

  • Oh, Jang-Jin;Jun, Jae-Shik;Hah, Suck-Ho;Kim, Wuon-Shik;Hwang, Sun-Tae
    • Journal of Radiation Protection and Research
    • /
    • v.13 no.2
    • /
    • pp.21-28
    • /
    • 1988
  • Absorbed dose in water was analyzed by Burlin's general cavity theory for medium X-ray energy region (HVL : 0.29, 0.84, 1.60, 2.62mm Cu) using LiF : PTFE TL dosimeter(0.4 mm ${\times}\;{\phi}$ 12.5mm, hot-pressed LiF TLD-700) which was enclosed in lucite capsule. The absorbed dose rate at 5cm depth in water phantom was determined with measurement error of ${\pm}5%$. This result was compared to that of the ionization method, indirectly absolute measurement method, of which measurement error of ${\pm}2%$. The difference between these two results lies within measurement error of LiF : PTFE method. Therefore, the absorbed dose in water obtained by LiF: PTFE is reliable, and this result suggests the base to estimate dose-equivalent for medium X-rays.

  • PDF

Intercomparison Exercise at Harshaw 6600, DVG-02TM, and D-Shuttle Dosimeters for the Individual Monitoring of Ionizing Radiation

  • Kim, Dmitriy Spartakovich;Murayama, Kentaro;Nurtazin, Yernat;Koguchi, Yasuhiro;Kenzhin, Yergazy;Kawamura, Hiroshi
    • Journal of Radiation Protection and Research
    • /
    • v.44 no.2
    • /
    • pp.79-88
    • /
    • 2019
  • Background: The main goal of experiments is to compare various operational and technical characteristics of D-Shuttle semiconductor personal dosimeters of the Japanese company "Chiyoda Technol Corporation" and Harshaw thermoluminescent dosimeters (TLD) manufactured by "Thermo Fisher Scientific" and DTL-02 of the Russian Research and Production Enterprise (RPE) "Doza" by their occupational and calibration exposure at various dose equivalents from 0.5 to 20 mSv of gamma-radiation. Materials and Methods: Besides dosimeters DTL-02, D-Shuttle and Harshaw TLD, there were also used: (1) the primary reference radionuclide source Hopewell Designs IAEA: G10-1-12 with $^{137}Cs$ isotope (an error is not more than 6% and activity is 20 Ci), and (2) the verification device UPGD-2M of RPE "Doza" and installed in the National Center for Expertise and Certification of the Republic of Kazakhstan (Kapchagai, the National Center for Expertise and Certification). Results and Discussion: The main results of researches are the following: (1) TLDs for Harshaw 6600 and DVG-02TM have an approximately equal measurement accuracy of the individual dose equivalents in the range from 0.5 to 20 mSv of gamma-radiation. (2) Advantages of dosimeters for Harshaw 6600 are due to the high measurement productivity and opportunity to indicate the dose on the skin $H_p$(0.07). Advantages of DVG-02TM consist of operation simplicity and lower cost than of Harshaw 6600. (3) D-Shuttles are convenient for use in the current and the operational monitoring of ionizing radiation. Measurement accuracy and 10% linearity of measurements are ensured when D-Shuttle is irradiated with dose equivalents below 1 mSv at the equivalent dose rate not higher than $3mSv{\cdot}hr^{-1}$. This allows using D-Shuttle at a routine technological activity. Conclusion: The obtained results of experiments demonstrate advantages and disadvantages of D-Shuttle semiconductor dosimeters in comparison with two TLD systems of DVG-02TM and Harshaw 6600.

Acute Kidney Injury after Dose-Titration of Liraglutide in an Obese Patient (비만 환자에서 리라글루티드 증량 과정에서 발생한 급성 신손상)

  • Lee, Hee Jin;Park, Hye Soon
    • Archives of Obesity and Metabolism
    • /
    • v.1 no.2
    • /
    • pp.78-82
    • /
    • 2022
  • Liraglutide (SaxendaR) is prescribed to induce and sustain weight loss in obese patients. The starting dose of liraglutide is 0.6 mg/day for 1 week, which is increased by 0.6 mg/day every week until the full maintenance dose of 3 mg/day is achieved. Such dose titration is needed to prevent side effects, which primarily include gastrointestinal problems such as nausea, diarrhea, constipation, vomiting, dyspepsia, and abdominal pain. A 35-year-old, reportedly healthy obese man receiving liraglutide treatment for obesity visited the emergency room complaining of generalized weakness and dizziness accompanied by repeated diarrhea and vomiting. He reported over 20 episodes of diarrhea starting the day after liraglutide dose escalation from 1.2 mg/day to 1.8 mg/day. Laboratory findings suggested pre-renal acute kidney injury, including serum creatinine 4.77 mg/dl, blood urea nitrogen (BUN) 37 mg/dl, estimated glomerular filtration rate (eGFR) 15 ml/min/1.73 m2, and Fractional excretion of sodium 0.08. After volume repletion therapy, his renal function recovered to a normal range with laboratory values of creatinine 1.08 mg/dl, BUN 14 mg/dl, and eGFR 88 ml/min/1.73 m2. This case emphasizes the need for caution when prescribing glucagon-like peptide-1 receptor agonists, including liraglutide, given the risk of serious renal impairments induced by volume depletion and dehydration through severe-grade diarrhea and vomiting.