• 한국환경농학회지
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• 제19권4호
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• pp.328-331
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• 2000

국내에서 재배중인 옥수수 재래종 (고성, 영월)품종의 종자에 저선량 ${\gamma}$선을 조사하여 초기생육과 수량에 미치는 영향을 온실과 포장실험으로 조사하였다. 저선량 방사선 조사가 옥수수 종자발아 및 초기생육에서 뚜렷한 촉진효과를 보였으나 품종별로 다소 차이가 있었으며 고성재래종은 2 Gy, 영월재래종은 12 Gy가 가장 효과적이었다. 포장생장과 수량에서도 저선량 조사에 의해 증가하는 경향을 보였는데 적정선량은 고성재래종은 8 Gy, 영월재래종은 $4{\sim}12$ Gy 범위로 나타났다.

• 대한두경부종양학회지
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• 제27권1호
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• pp.47-53
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• 2011

Purpose : Concurrent chemoradiotherapy(CCRT) with 3 weekly cisplatin is the standard treatment of locally advanced head and neck cancer(HNC). The aim is to evaluate the efficacy and toxicities of low-dose weekly cisplatin-based CCRT, which was devised to reduce the toxicity of CCRT. Method : We retrospectively analyzed HNC patients who received low-dose weekly cisplatin-based CCRT between 2008 and 2010. Cisplatin 35mg/$m^2$ was weekly given to all patients during radiotherapy. The efficacy was evaluated by the degree of clinical response, treatment failure and survival. The toxicity was evaluated by hematologic toxicities and oral mucositis. Results : A total of 27 patients were analyzed and median age was 59(range 31-81). The ratio of administered dose of radiotherapy and cisplatin to planned dose were 0.98 and 0.93, respectively. Complete remission and partial remission were 73% and 23%, respectively. Treatment failure was observed in 8(30%) patients. 1-year survival rate and 1-year disease free survival rate were 82% and 59%, respectively. Overall survival and progression-free survival did not reach median time. Grade 3/4 anemia, neutropenia, thrombocytopenia and oral mucositis were observed in 11%, 19%, 7% and 32% of patients, respectively. In terms of administered cycles, however, only 1-3% of grade 3/4 hematologic toxicities occurred among total 190 cycles. Severe oral mucositis were statistically associated with old age(p=0.003). Treatment failure had no statistical relation with age, pathology, primary site and stage. Conclusion : Low-dose weekly cisplatin-based CCRT seemed to deliver enough dose of cisplatin and to show low drop-out rate and good efficacy with low hematologic toxicities.

• 한국방사선학회논문지
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• 제15권6호
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• pp.813-819
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• 2021

본 연구에서는 방사성 불소의 인체 내 주입 시 방사선 방호목적으로 사용되는 L-블럭형 방호장비의 차폐율과 주변공간의 선량분포를 몬테칼로 방법을 이용해 계산하였다. L-블럭형 차폐장치의 몸체 및 윈도우 부위의 차폐율은 99.99 %였다. 1 m거리에서 계산한 선량분포는 XZ평면의 135°, 45°, 225°, 315°, 180°에서 상대적으로 높게 나타났고, 0°, 90°, 270°에서는 매우 낮게 계산되었다. YZ평면에서는 135°, 180°, 225°에서 상대적으로 높게 나타났고, 나머지 각도에서는 매우 낮게 계산되었다. AZ와 BZ 평면에서도 YZ평면과 유사한 결과를 나타냈다. 또한 선원의 수평방향과 선원의 상방 45°방향의 선량분포를 통해 225°~315°범위에서 차폐율이 가장 우수함을 확인하였다. 이와 같은 결과가 방사선 작업 종사자들의 방사선 방호에 필요한 기초자료로 활용되기를 기대한다.

• 제어로봇시스템학회논문지
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• 제9권4호
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• pp.296-303
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• 2003

A personal portable type electronic dosimeter using silicon PIN photodiode and small GM tube is recently attracting much attention due to its advantages such as an immediate indication function of dose and dose rate, alerting function, and efficient management of radiation exposure history and dose data. We designed and manufactured a semiconductor radiation detector aimed to directly measure X-ray and v-ray irradiated in silicon PIN photodiode, without using high-priced scintillation materials. Using this semiconductor radiation detector, we developed an active electronic dosimeter, which measures the exposure dose using pulse counting method. In this case, it has a shortcoming of over-evaluating the dose that shows the difference between the dose measured with electronic dosimeter and the dose exposed to the human body in a low energy area. We proposed an energy compensation filter and developed a dose conversion algorithm to make both doses indicated on the detector and exposed to the human body proportional to each other, thus enabling a high-precision dose measurement. In order to prove its reliability in conducting personal dose measurement, crucial for protecting against radiation, the implemented electronic dosimeter was evaluated to successfully meet the IEC's criteria, as the KAERI (Korea Atomic Energy Research Institute) conducted test on dose indication accuracy, and linearity, energy and angular dependences.

• Radiation Oncology Journal
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• 제2권1호
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• pp.129-137
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• 1984

In brachytherapy, it is important to determine the positions of the radiation sources which are inserted into a patient and to estimate the dose resulting from the treatment. Calculation of the dose distribution throughout an implant is so laborious that it is rarely done by manual methods except for model cases. It is possible to calculate isodose distributions and tumor doses for individual patients by the use of a microcomputer. In this program, the dose rate and dose distributions are calculated by numerical integration of point source and the localization of radiation sources are obtained from two radiographs at right angles taken by a simulator developed for the treatment planning. By using microcomputer for brachytherapy, we obtained the result as following 1. Dose calculation and irradiation time for tumor could be calculated under one or five seconds after input data. 2. It was same value under$\pm2\%$ error between dose calculation by computer program and measurement dose. 3. It took about five minutes to reconstruct completely dose distribution for intracavitary irradiation. 4. Calculating by computer made remarkly reduction of dose errors compared with Quimby's calculation in interstitial radiation implantation. 5. It could calculate the biological isoffect dose for high and low dose rate activities.

• Clinical and Experimental Pediatrics
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• 제60권1호
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• pp.24-29
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• 2017

Purpose: Previously, Kawasaki disease (KD) treatment with low-dose aspirin was administered for 6-8 weeks after the acute phase. However, inflammatory marker levels normalize before 6-8 weeks. In this study, we aimed to investigate the clinical outcome of short-term low-dose aspirin treatment based on inflammatory and thrombotic marker levels. Methods: We performed a retrospective review of the medical records of patients with KD who were hospitalized at Chungnam National University Hospital between September 2012 and May 2014. When fever subsided, low-dose aspirin treatment was started. Inflammatory (white blood cell count, erythrocyte sedimentation rate, and C-reactive protein) and thrombotic markers (D-dimer) were monitored at follow-ups conducted in 1- to 2-week intervals. The low-dose aspirin administration was terminated when both markers were normalized and no cardiovascular complications were observed. Results: Eighty-four patients with KD (complete KD, n=49; incomplete KD, n=35) were enrolled. The inflammatory and thrombotic marker levels were normalized within 3-4 weeks on average. At the beginning the low-dose aspirin treatment, 9 patients had coronary artery lesions but 75 did not. When the low-dose aspirin administration was terminated at the time the inflammatory marker levels were normalized, no new CALs developed during the follow-up at 6-8 weeks. Conclusion: Most of the inflammatory marker levels were normalized within 3-4 weeks after the acute phase of KD. New cardiovascular complications did not develop during the course of the short-term aspirin treatment based on the inflammatory marker levels, clinical findings, and echocardiography.

• 대한방사선기술학회지:방사선기술과학
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• 제23권1호
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• pp.13-19
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• 2000

We have presented with the "A study on overexposure rate according to over-density in chest X-ray radiography(I)" last year. In this report, We could calculate the entrance skin dose from chest X-ray film density the formula $I_0=Ix/e^{-{\mu}x}{\times}mG$, (mG is Bucky factor) was used to deliver the skin dose. At that time, There was two problems that the Bucky factor from maker was not equal to field experience and the field size influenced on the Attenuation Rate. The experiment of Bucky factor was done from film method and retried the Attenuation Rate of Acryle phantom according to Good & Poor geometry. As the results, The Bucky factor from maker higher than in this experiments $30{\sim}40%$. The Attenuation Rate in good geometric condition brings about a little alteration compare with poor geometric condition. In the field experiment, we could get the chest image with very low entrance skin radiation dose $29.3{\mu}Sv$, especially with air gap methode, the entrance skin dose was detected $10{\mu}Sv$.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4121-4126
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• 2013

Objective: Low dose radiation may stimulate the growth and development of animals, increase life span, enhance fertility, and downgrade the incidence of tumor occurrence.The aim of this study was to investigate the antitumor effect and hormesis in an erythrocyte system induced by low-dose radiation. Methods: Kunming strain male mice were subcutaneously implanted with S180 sarcoma cells in the right inguen as an experimental in situ animal model. Six hours before implantation, the mice were given 75mGy whole body X-ray radiation. Tumor growth was observed 5 days later, and the tumor volume was calculated every other day. Fifteen days later, all mice were killed to measure the tumor weight, and to observe necrotic areas and tumor-infiltration-lymphoreticular cells (TILs). At the same time, erythrocyte immune function and the level of 2,3-diphosphoglyceric acid (2,3-DPG) were determined. Immunohistochemical staining was used to detect the expression of EPO and VEGFR of tumor tissues. Results: The mice pre-exposed to low dose radiation had a lower tumor formation rate than those without low dose radiation (P < 0.05). The tumor growth slowed down significantly in mice pre-exposed to low dose radiation; the average tumor weight in mice pre-exposed to low dose radiation was lighter too (P < 0.05). The tumor necrosis areas were larger and TILs were more in the radiation group than those of the group without radiation. The erythrocyte immune function, the level of 2,3-DPG in the low dose radiation group were higher than those of the group without radiation (P < 0.05). After irradiation the expression of EPO of tumor tissues in LDR group decreased with time. LDR-24h, LDR-48h and LDR-72h groups were all statistically significantly different from sham-irradiation group. The expression of VEGFR also decreased, and LDR-24h group was the lowest (P < 0.05). Conclusion: Low dose radiation could markedly increase the anti-tumor ability of the organism and improve the erythrocyte immune function and the ability of carrying $O_2$. Low-dose total body irradiation, within a certain period of time, can decrease the expression of hypoxia factor EPO and VEGFR, which may improve the situation of tumor hypoxia and radiosensitivity of tumor itself.

• 한국환경농학회지
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• 제21권3호
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• pp.202-207
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• 2002

참박과 호박 채종종자의 발아율을 증진시킬 수 있는 종자처리 방법을 확립하고자 저선량 감마선을 1$\sim$20 Gy 까지 조사하여 발아와 초기생육 및 생리활성을 관찰하였다. 저선량 조사한 참박과 호박종자의 발아율은 대조구보다 증가하는 경향을 보였는데 그 효과는 종자상태에 따라 다르게 나타났다. 참박 70$\sim$80% 발아율종자의 발아는 4$\sim$20 Gy에서 증가하였는데 특히 4 Gy조사에서 가장 높았고, 80$\sim$90% 발아율종자도 4 Gy 조사에서 효과를 보였다. 파종 4일 후의 발아율은 참박 70$\sim$80%와 80$\sim$90% 발아율 종자의 경우는 4 Gy조사에서 대조구보다 각각 66%와 26% 증가하였고, 호박의 70$\sim$80% 발아율종자는 2 Gy 조사에서, 80$\sim$90% 발아율종자는 8 Gy 조사에서 향상되었다. 저선량 조사한 유묘생육은 발아율이 증가한 선량에서 증가하였는데 특히 호박 70$\sim$80% 종자의 2 Gy 조사에서 가장 높았다. 파종 6일 후에 조사한 참박의 효소활성은 4 Gy 조사시에 단백질과 catalase 활성이, 호박의 경우는 catalase와 peroxidase 활성이 2 Gy와 8 Gy 조사에서 증가하였다. 참박과 호박종자의 발아와 유묘생육 및 생리활성은 저선량 감마선 조사에 의해 촉진됨을 확인할 수 있었다.

• Toxicological Research
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• 제15권1호
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• pp.9-17
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• 1999

This study was performed to evaluate the subacute toxicity of CJ-50002 (Vibrio Vaccine) in SPF Spraqur-Dawley (SD) rats. Vibrio vaccine was administered orally at a dose level of high (167mg/kg/day), medium (16.7mg/kg/day), and low (16.7mg/kg/day) once a day and repeated fro 4 weeks. Ten males and female rats were assigned to each group. After 4 week administration, no significant dose-dependent changes in body weight, water and food consumption rate or organ weight were noted dependent changes in body weight, water and food consumption rate or organ weight were noted among 4 groups. Urinanalysis, hematology, and serum chemistry, also fail to detect any dose-related change among 4 groups tested. During necropsy and histopathological examination, no specific toxicity related to treated material was found. The result of this study demonstrated that vibrio vaccine when administered orally for 4 weeks at a high dose of 167mg/kg/day, no dose-related toxicity was found in treated make and female rats.