• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.328-331
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• 2000

Maize (Zea mays L. cv. kosungjaerae and cv. youngwoljaerae) seeds were irradiated with the dose of $0.5{\sim}20$ Gy by $^{60}Co\;{\gamma}-ray$ radiation to investigate the effect of the low dose ${\gamma}-ray$ radiation on the germination rate, early growth and yield. The low dose radiation was able to improve the germination rate and early growth in maize, but the optimal radiation doses were different depended on kinds of cultivars. High stimulatory effect in early growth of maize was observed in 2 Gy irradiation group of kosungjaerae cultivar and in 12 Gy irradiation group of youngwoljaerae cultivar. The optimal radiation dose for the enhancement of yield and yield components in maize was 8 Gy in kosungjaerae cultivar and $4{\sim}12$ Gy in youngwoljaerae cultivar.

• Korean Journal of Head & Neck Oncology
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• v.27 no.1
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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.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.813-819
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• 2021

In this study, the shielding rate of L-block-type shielding equipment used for radiation protection when radioactive fluorine is injected into the human body and the dose distribution of the space in the injection room were calculated using the Monte Carlo method. The shielding rate of the body and window parts of the L-block-type shielding equipment was 99.99%. The dose distribution calculated at a distance of 1 m was relatively high at 135°, 45°, 225°, 315°, and 180° of the XZ plane, and was calculated to be very low at 0°, 90°, and 270°. In the YZ plane, it was relatively high at 135°, 180°, and 225°, and was calculated very low at the remaining angles. The AZ and BZ planes also showed similar results to the YZ plane. In addition, it was confirmed that the shielding rate was the best in the range of 225° to 315° through the dose distribution in the horizontal direction of the source and the 45° direction above the source. These results can be used as basic data necessary for radiation protection of radiation workers.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.4
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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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• v.2 no.1
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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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• v.60 no.1
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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.

• Journal of radiological science and technology
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• v.23 no.1
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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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• v.14 no.7
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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.

• Korean Journal of Environmental Agriculture
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• v.21 no.3
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• pp.202-207
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• 2002

To establish the seed treatment method of the gamma radiation for germination enhancement of bottle gourd(Lagenaria siceraria Standl.) and pumpkin(Cucurbita ficifolia Bouche), seeds were irradiated with the dose of 1$\sim$20 Gy of the gamma radiation. The germination rate in irradiated group was higher than that of the control, depending on seed condition. In the case of bottle gourd, the germination rate of 70$\sim$80% germinative seed was increased at 4$\sim$20 Gy irradiated groups. Especially, it was the highest at 4 Gy irradiated group. The germination rate of 80$\sim$90% germinative seed was the highest at 4 Gy irradiated group. The germination rate of 70$\sim$80% and 80$\sim$90% germinative seed at 4 days after sowing was increased 66% and 26% at 4 Gy irradiated group, respectively. In the case of pumpkin, the germination rate of 70$\sim$80% and 80$\sim$90% germinative seed was increased at 2 Gy and 8 Gy irradiated group, respectively. Effect of the low-dose gamma radiation on the early growth was enhanced depending on their germination enhancement. Especially, it was the highest at 2 Gy irradiated group of 70$\sim$80% germinative seed of pumpkin. Catalase activity of bottle gourd was increased at 4 Gy irradiated group. Catalase and peroxidase activity of pumpkin were increased at 2 Gy and 8 Gy irradiated group. These results suggest that the germination, early growth and physiological activity of bottle gourd and pumpkin seeds could be promoted by the low dose gamma radiation.

• Toxicological Research
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• v.15 no.1
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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.