• Title/Summary/Keyword: Low dose rate

검색결과 580건 처리시간 0.036초

Radiation Biology in Space; DNA Damage and Biological Effects of Space Radiation

  • Ohnishi, Takeo;Takahashi, Akihisa;Ohnishi, Ken
    • Journal of Photoscience
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    • 제9권3호
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    • pp.37-40
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    • 2002
  • Astronauts are constantly exposed to space radiation at a low-dose rate during long-tenn stays in space. Therefore, it is important to determine correctly the biological effects of space radiation on human health. Space radiations contain various kinds of different energy particles, especially high linear energy transfer (LET) particles. Therefore, we have to study the relative biological effectiveness (RBE) of space radiation under microgravity environment which may change RBE from a stress for cells. Furthermore, the research about space radiation might give us useful information about birth and evolution of life on the earth. We also can realize the importance of preventing the ozone layer from depletion by use of exposure equipment to sunlight at International Space Station (ISS).

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자궁경부암에서 대동맥 임파절 전이의 치료 (Radiotherapy of Para-Aortic Node Metastases in Carcinoma of the Uterine Cervix)

  • 이종영;서창옥;성진실;김귀언;노준규
    • Radiation Oncology Journal
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    • 제7권2호
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    • pp.259-267
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    • 1989
  • Forty one patients with para-aortic node metastases from carcinoma of the uterine cervix treated with radiotherapy at Department of Radiation Oncology, Yonsei University, College of Medicine from January 1982 to December 1987 were retrospectively analyzed. Eleven patients were diagnosed at the time of diagnosis of carcinoma of the cervix (early diagnosis) and 30 patients were diagnosed during follow up period after definitive radiotherapy of primary site (late diagnosis). The most important factors affecting the survival in this study were time of diagnosis and dose of irradiation. Overall 5 year actuarial survival rate of 41 patients was $25.7\%$. Five year survival rate for early diagnosis was $60.3\%$, but late diagnosis was $16.9\%$. And survival rate for high dose (over 4000 cGy) radiation group and low dose radiation group were $42.2\%\;and\;8.9\%$ respectively The most leading cause of death was para-aortic node failure, so early diagnosis and maximum palliation with full dose radiotherapy (over 4000 cGy) is necessary to improve the survival and the quality of life.

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Gamma Knife Radiosurgery for Trigeminal Neuralgia : Review and Update

  • Lee, Seunghoon;Lee, Jung-Il
    • Journal of Korean Neurosurgical Society
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    • 제65권5호
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    • pp.633-639
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    • 2022
  • Accurate diagnosis of trigeminal neuralgia (TN) is the starting point for optimal treatment. Gamma knife radiosurgery (GKRS) is currently regarded as one of the first-line treatment options for medically refractory TN. GKRS is a less invasive treatment with a low risk of complications than other surgical procedures that provides a favorable pain control Barrow Neurological Institute (BNI) I-IIIb rate of >75% at short-term follow-up. Drawbacks of GKRS include the latency period before pain relief and higher recurrence rate compared with microvascular decompression. Therefore, repeat treatment is necessary if the initial GKRS was effective but followed by recurrence. The concept of dose rate and the biologically effective dose of radiation has been actively studied in radiation oncology and is also applied in GKRS for TN to achieve high safety and efficacy by prescribing the optimal dose. Recent progress in functional imaging, such as diffusion tensor imaging, enables us to understand the pathophysiology of TN and predict the clinical outcome after GKRS. Here, we review TN, GKRS, and recent updates, especially in the concepts of radiation dose, diffusion tensor imaging studies, and repeat treatment in GKRS for TN.

마우스에서 전신 저선량 분할 방사선 조사에 의한 면역학적 변화 평가 (Effects of Low-Dose Fractionated Total Body Irradiation on Murine Immune System)

  • 김미형;유상영;임대석;송지영
    • Journal of Radiation Protection and Research
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    • 제39권3호
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    • pp.134-141
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    • 2014
  • 방사선요법은 항암 치료에서 널리 이용되는 요법으로, 항암치료에 저선량 방사선을 이용하는 것에 대한 관심이 증가되고 있고, 저선량 방사선의 다양한 생물학적 효과가 있음이 보고되고 있다. 그러므로 본 연구에서는 마우스 모델에서 저선량 방사선이 면역반응에 어떠한 영향을 미치는지, 또한 이를 감지할 수 있는지를 조사하였다. C57BL/6 마우스에 $^{137}Cs$ 선원을 이용하여 연속 3일간 총 90 mGy의 저선량 방사선을 전신 조사한 후 마지막 방사선 조사 2, 14, 28일 후에 마우스를 희생시켜 말초 혈액 세포수, 비장 세포수, 비장 내 면역세포의 비율과 활성화 정도를 분석하였다. 말초 혈액 검사를 통해, 저선량 방사선 조사군에서 적혈구와 혈소판 수의 유의적 변화는 관찰할 수 없었으며, 백혈구 수는 마지막 방사선 조사 후 2일째에 선량-의존적인 감소를 보였으나, 점차 회복되는 경향을 나타냈다. 비장세포 수도 2일째 감소를 보였지만 서서히 그 수가 증가됨을 확인하였다. 2일과 14일째에 비장세포의 Foxp3 mRNA가 감소된 반면, CD4 T 세포와 CD69 양성세포가 증가되었다. 마우스에서 분할 저선량 방사선을 전신조사한 결과, 방사선조사군에서 특이적인 임상 증상이나 유의적인 체중감소를 보이지 않았다. 본 연구에서는 마우스를 대상으로 저선량을 분할 조사하였을 경우에도 면역학적 변화를 확인할 수 있으며 이를 통해 향후 저선량 방사선의 생물학적 효과를 뒷받침하는 자료로 활용할 수 있으리라 기대한다.

한의학 치료율 제고 방안에 관한 연구 (Treatment Rate-up Methods in the Oriental Medicine)

  • 이선동
    • 대한예방한의학회지
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    • 제3권1호
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    • pp.35-54
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    • 1999
  • This thesis shows about the meaning of treatment rate increasing, the current treated level and the reason of low treatment rate and increasing methods. 1. Treatment rate incresing means high treat level within short time, keeping treatment effect for a long time as well as raising treatment rate. 2. The current by diseases each others completed treatment rate of oriental medicine is 14.0% to 89.7%$(mean:\;{\pm}40.0%)$. Therefore the rate is show too low. 3. The reasons of low treatment rate; low academic level of oriental, academic limitation, clinic and prevention problem of oriental medicine, lack of medical approch suitable for current diseases and symptoms, mostly incurrable diseases using oriental medicine, lack of preventive education, disappropriate medical service and nonspecialty of the treatment, etc. 4. The next methods for incresing the treatment rate must be improved; such as accurate establishment of process that diagnosis symptoms and treats them, system research of microdiagnosis, positive treatment with medicine and nonmedicine method at the same time, appropriate subdivision and actualization of clinical basic research, research of dose and response, diversity of treatment methods and forms, development of treatment service and prevention based on health level, enormous change as cure medicine and opening-up of new disease field, specialization of medical examination, reinforcement of public medical part and herbal drugs use with same origin, mental and pysical stability of patients, accurate extract and oral drinking ways, etc.

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Study on Dose Rate on the Surface of Cask Packed with Activated Cut-off Pieces from Decommissioned Nuclear Power Plant

  • Park, Kwang Soo;Kim, Hae Woong;Sohn, Hee Dong;Kim, Nam Kyun;Lee, Chung Kyu;Lee, Yun;Lee, Ji Hoon;Hwang, Young Hwan;Lee, Mi Hyun;Lee, Dong Kyu;Jung, Duk Woon
    • Journal of Radiation Protection and Research
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    • 제45권4호
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    • pp.178-186
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    • 2020
  • Background: Reactor pressure vessel (RV) with internals (RVI) are activated structures by neutron irradiation and volume contaminated wastes. Thus, to develop safe and optimized disposal plan for them at a disposal site, it is important to perform exact activation calculation and evaluate the dose rate on the surface of casks which contain cut-off pieces. Materials and Methods: RV and RVI are subjected to neutron activation calculation via Monte Carlo methodology with MCNP6 and ORIGEN-S program-neutron flux, isotopic specific activity, and gamma spectrum calculation on each component of RV and RVI, and dose rate evaluation with MCNP6. Results and Discussion: Through neutron activation analysis, dose rate is evaluated for the casks containing cut-off pieces produced from decommissioned RV and RVI. For RV cut-off ones, the highest value of dose rate on the surface of cask is 6.97 × 10-1 mSv/hr and 2 m from it is 3.03 × 10-2 mSv/hr. For RVI cut-off ones, on the surface of it is 0.166 × 10-1 mSv/hr and 2 m from it is 1.04 × 10-1 mSv/hr. Dose rates for various RV and RVI cut-off pieces distributed lower than the limit except the one of 2 m from the cask surface of RVI. It needs to adjust contents in cask which carries highly radioactive components in order to decrease thickness of cask. Conclusion: Two types of casks are considered in this paper: box type for very-low-level waste (VLLW) as well as low-level waste (LLW) and cylinder type for intermediate-level waste (ILW). The results will contribute to the development of optimal loading plans for RV and RVI cut-off pieces during the decommissioning of nuclear power plant that can be used to prepare radioactive waste disposal plans for the different types of wastes-ILW, LLW, and VLLW.

묵은 배추종자의 발아와 생육에 미치는 저선량 ${\gamma}$선 효과 (Influence of the Low Dose ${\gamma}$-ray Radiation on the Old Seed Germination and Growth of Chinese Cabbage)

  • 김재성;이영근;백명화;이영복;박영선
    • 환경생물
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    • 제17권1호
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    • pp.11-15
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    • 1999
  • 저선량 방사선에 의한 식물 유익효과를 구명하기 위하여 2개 종묘회사로부터 4년간 묵은 종자를 분양받아 저수준의 ${\gamma}$선을 조사하여 온실과 포장에서 재배하여 그 생육 상황을 조사하였다. 서울종묘의 한여름배추는 0.5 Gy 조사구를 제외하고는 발아율 증대효과는 없었고 8 Gy와 12 Gy 조사구에서 유묘초장과 생체중이 각각 평균 20%와 40%정도 증가하여 초기생육 촉진효과는 있었으나 포장수량 증가 효과는 볼 수 없었다. 흥농종묘의 tropic emperor 품종에서는 1 Gy 조사에서 발아율이 10% 정도 증가하였고 유묘초장과 생체중은 1 Gy와 12 Gy 조사구에서 평균 20% 정도 증가하였으며 포장수량에서도 0.5 Gy와 4 Gy에서 초장과 생체중이 각각 10%와 20%정도 증가하였다. 결과적으로 저선량 방사선에 의한 배추의 초기생육 촉진효과가 있는 것으로 사료된다.

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Low-dose intravenous ketamine versus intravenous ketorolac in pain control in patients with acute renal colic in an emergency setting: a double-blind randomized clinical trial

  • Sotoodehnia, Mehran;Farmahini-Farahani, Mozhgan;Safaie, Arash;Rasooli, Fatemeh;Baratloo, Alireza
    • The Korean Journal of Pain
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    • 제32권2호
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    • pp.97-104
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    • 2019
  • Background: This study was conducted to compare the effectiveness of low-dose ketamine versus ketorolac in pain control in patients with acute renal colic presenting to the emergency department (ED). Methods: This is a double-blind randomized clinical trial. The initial pain severity was assessed using the numerical rating scale (NRS). Then, ketamine or ketorolac was administered intravenously at a dose of 0.6 mg/kg and 30 mg respectively. The pain severity and adverse drug reactions were recorded 5, 15, 30, 60, and 120 min thereafter. Results: The data of 62 subjects in the ketamine group and 64 patients in the ketorolac group were analyzed. The mean age of the patients was $34.2{\pm}9.9$ and $37.9{\pm}10.6\;years$ in the ketamine and ketorolac group, respectively. There was no significant difference in the mean NRS scores at each time point, except for the 5 min, between the two groups. Despite a marked decrease in pain severity in the ketamine group from drug administration at the 5 min, a slight increase in pain was observed from the 5 min to the 15 min. The rate of adverse drug reactions, including dizziness (P = 0.001), agitation (P = 0.002), increased systolic blood pressure (> 140 mmHg), and diastolic blood pressure (> 90 mmHg) was higher in the ketamine group. Conclusions: Low dose ketamine is as effective as ketorolac in pain management in patients with renal colic presenting to the ED. However, it is associated with a higher rate of adverse drug reactions.

분화성 갑상선암환자의 방사성 요오드 치료시 전리함과 Geiger-Muller계수관에서 방사선량률 측정값 비교 (Comparison of the Measured Radiation Dose-rate by the Ionization Chamber and GM(Geiger-Müller) Counter After Radioactive Iodine Therapy in Differentiated Thyroid Cancer Patients)

  • 박광훈;김구환
    • 대한방사선기술학회지:방사선기술과학
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    • 제39권4호
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    • pp.565-570
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    • 2016
  • 방사성 요오드($^{131}I$) 치료는 분화성 갑상선암 환자에서 재발을 감소시키고 생존률을 증가시키나, 환자에서 방출되는 방사능으로 인하여 피폭을 야기시킬 수 있으므로 환자로부터 발생되는 방사선량률을 측정하는 것이 방사선안전관리 측면에서 중요하다. 방사성 요오드($^{131}I$) 치료시 널리 사용되는 측정기 중 전리함과 GM계수관으로 측정된 방사선량률의 감도와 측정효율을 구하였다. 방사성 요오드($^{131}I$)를 150mCi 경구투여 받은 분화성 갑상선암 환자의 상복부로부터 1 m거리에서 경과 시간에 따라 방사선량률을 측정하였다. 시간에 따른 변화를 직접적으로 비교한 결과, 고선량률에서의 감도와 측정효율은 GM계수관보다 전리함이 높게 나타났고, 통계적으로 유의하였다(p<0.05). 저선량률에서의 감도와 측정효율은 GM계수관보다 전리함이 낮게 나타났지만 통계적으로 유의한 차이를 나타내지 않았다(p>0.05). 방사성 요오드($^{131}I$) 치료시에 검 교정이 완료된 전리함과 GM계수관으로 정확하고 신속한 방사선량률을 측정하여 환자에게 설명함으로써 방사성 요오드 치료 후 퇴원하는 환자에게 환자가족 또는 주변 사람들에게 미칠 수 있는 방사선피폭을 예측하고, 불필요한 예단을 줄여줄 수 있을 것이다.