• 한국환경농학회지
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• 제17권4호
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• pp.368-370
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• 1998

In order to determine the optimal radiation dose for the sterilization of biowastes, the bioburden, frequencies and radiosensitivities of bacteria, mold and fungi in rice straw, chaff, corn stover and sawdust was observed before and after ${\gamma}-ray$ irradiation. Radiation sterilization dose of rice straw, chaff, com stover and sawdust was calculated as 17.7, 17.6, 15.6 and 20.0kGy, respectively, from the mutual compensation of screening dose and derived dose on the basis of $10^{-3}$ SAL. This method could be acceptable for the sterilization of various biowastes including food, pharmaceuticals, etc.

• Journal of Radiation Protection and Research
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• 제46권1호
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• pp.8-13
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• 2021

Background: Salmonella enteritidis (SE) was the main cause of the pandemic of foodborne salmonellosis. The surface of eggs' shells can be contaminated with this bacterium; however, washing them with sodium hypochlorite solution not only reduces their flavor but also heavily impacts the environment. An alternative to this is surface sterilization using low-energy electron beam. It is known that irradiation with 1 kGy resulted in a significant 3.9 log reduction (reduction factor of 10,000) in detectable SE on the shell. FAO/IAEA/WHO indicates irradiation of any food commodity up to an overall average dose of 10 kGy presents no toxicological hazard. On the other hand, the Food and Drug Administration has deemed a dose of up to 3 kGy is allowable for eggs. However, the maximum dose permitted to be absorbed by an edible part (i.e., internal dose) is 0.1 Gy in Japan and 0.5 Gy in European Union. Materials and Methods: The electron beam (EB) depth dose distribution in the eggshell was calculated by the Monte Carlo method. The internal dose was also estimated by Monte Carlo simulation and experimentation. Results and Discussion: The EB depth dose distribution for the eggshells indicated that acceleration voltages between 80 and 200 kV were optimal for eggshell sterilization. It was also found that acceleration voltages between 80 and 150 kV were suitable for reducing the internal dose to ≤ 0.10 Gy. Conclusion: The optimum irradiative conditions for sterilizing only eggshells with an EB were between 80 and 150 kV.

• 한국방사선학회논문지
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• 제14권5호
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• pp.537-543
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• 2020

현대사회의 노인 인구는 첨단 의료기술과 최소 침습 수술로 인해 빠르게 성장하고 있다. 따라서 의료기기를 사용하는 경향이 증가하기 때문에 병원성 감염이 우려된다. 따라서 현대 의학의 최우선 목표는 감염예방이다. 최근 3D 프린팅을 이용하여 환자 맞춤형 임플란트 이식술이 늘고 있다. 대표적 재료로 이용되는 것이 수산화인회석이다. 현재 HA 디스크 멸균을 위한 흡수선량 기준이 없으므로, HA 디스크 표면에 오염된 대장균과 충치균을 감마선 코발트와 선형 가속기를 이용하여 각 흡수선량 0, 0.5, 1.0, 3.0, 5.0 kGy로 조사 후, 십진 희석법으로 검체에서 균 수를 측정하였다. 멸균 후 대장균, 충치균의 생존 비교분석을 위해 비모수 검정법을 시행하였으며, 그 결과 대장균은 1 kGy 이상, 충치균은 3 kGy 이상에서 멸균되었다. 방사선 멸균 흡수선량 권고사항보다 낮은 수치에서 멸균을 시행하는 것도 가능할 것으로 생각된다.

• 미생물학회지
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• 제11권4호
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• pp.181-188
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• 1973

For the bulk sterilization, there are two traditional methods of autoclaving and exposure to ethylene oxide. However, autoclaving involves high temperatures and pressures and ethylene oxide is chemically highly reactive, so these methods are radiation, we have carried out sterility and safety tests on some medical products irradiated at varying radiation levels. The results obtained were as follows ; 1) The minimum dose of radiation for the sterilization of medical products was 2.5 Mrad. 2) The radiosterilization dose varied depending on the initial population of microorganisms. 3) In transfusion sets, a level of radiation of 2.5Mrad at room temperature produced no pyrogen and they remained bacteriologically sterile.

• Journal of Ginseng Research
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• 제6권2호
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• pp.143-148
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• 1982

This study was conducted to investigate to select the optimum condition for the sterilization of white ginseng powder. The powder heated at 100-121 $^{\circ}C$ for 1-30 minutes in a autoclave and irradiated at 2450 MHz microwave for 0.5-3.0 minutes was significantly changed in it's color density and become coagulated state, but their sterilizing effect on a general bacteria and 5. coli group were negligible. Meanwhile W- irradiation to the powder with thickness 1.5-10.5mm for 120 minutes was no changes in it's color. coagulated state and sterilizing effect, but 60Co-${\gamma}$ray irradiation at various dose with 0.1-2.0 Mrad was significant effect for sterilization and stability of the powder during the storage for 4 months at 25 $^{\circ}C$. The optimum dose of 60Co-${\gamma}$ ray irradiation was 0.5-0.7 Mrad.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권6호
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• pp.523-527
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• 2005

Allograft donations are commonly found to be contaminated. The most of tissue banks has promoted the use of ionizing radiation for the sterilization of biological tissues. The potential for transmission of human infectious diseases and contamination of microorganism has created serious concern for the continued clinical use of hard and soft-tissue allografts. Tissue banks have employed 15-25kGy for sterilization of hard and tendon allografts, which, according to the national standards, approaches the level at which the tissue quality is adversely affected for transplantation. The donations of allogeneic tissues to the Korea Tissue Bank over a 2-year period were reviewed, and the incidence and bacteriology of contamination were detailed. Clinical outcomes were determined for donors who had positive cultures at the time of retrieval and during the processing and they were compared with those of post sterilization. After exposure of the frozen block bone to 25kGy and the processed tissues to 15kGy of gamma irradiation, the authors were able to demonstrate complete inactivation of the bacteria. The aim of this study was to obtain the effects of gamma irradiation and the irradiation dose according to the type of tissue, through conventional microbiologic test without on influence of biocompatibility in allografts. The contamination rate after the final irradiation sterilization is 0% in the processed allografts. This may be due to the fact that the gamma radiation and processing steps are effective to control contamination.

• 한국안광학회지
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• 제17권1호
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• pp.99-105
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• 2012

목적: 본 연구는 UVA영역의 LED를 이용하여 안질환을 일으키는 대표적인 유발균인 녹농균과 포도상구균에 대한 살균효과를 알아보고, UVA영역의 LED를 콘택트렌즈 살균에 활용하고자 하였다. 방법: 안질환의 원인 세균인 녹농균과 포도상구균에 대한 살균효과 실험은 400 nm의 UVA-LED를 이용하여 소형 살균기기를 제작하여 녹농균은 $10^{-7}$ CFU/ml, 포도상구균은 $10^{-5}$ CFU/ml 로 각각 액체배지에 희석하여 넣은 후 시간대별로 15분, 30분, 60분, 120분, 240분, 360분, 480분 동안 각각 400 nm의 UVA를 조사하였다. 결과: 살균실험 결과를 직선회귀방정식(regresson line equation)으로 변환하여 목표 살균치(target log inactivation)를 도출한 결과 녹농균에 대한 3log inactivation의 UV조사량($mJ/cm^2$)이 54,847 UV dose($mJ/cm^2$)이었으며, 조사시간(irridiation time)은 135.42(min) 이었다. 또한 포도상구균의 3log inactivation은 39,066 UV dose($mJ/cm^2$)이었으며 조사시간은 98.72분이었다. 결론: 이러한 실험 결과 400 nm의 UVA-LED를 이용한 녹농균과 포도상구균에 대한 뛰어난 살균효과를 확인하였으며 콘택트렌즈의 살균에 유용하게 이용될 것으로 사료된다.

• 한국식품과학회지
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• 제17권4호
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• pp.311-318
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• 1985

This review was intended to develop the sterilization method of spices by gamma irradiation and the results are summarized as follows. Microbial load of spices was different according to the kind of spices and the number was ranged from $10^{2}$-$10^{5}/g$ to $10^{7}$-$10^{8}/g$, gamma irradiation up to 4-10 kGy could decreased or sterilized to the microorganism of spices. In physicochemical properties of spices such as chemical components,essential oil and flavor, irradiated group with optimum dose was almost similar to the nonirradiated one, while fumigant treated group was remarkably deteriorated in the properties of spices compared with control, and free radicals produced by irradiation was disappeared during a few days storage. Irradiated spices should be an aptitude for good quality the storeability of processing food. Optimum dose irradiation below less than that proposed by FAO/IAEA/WHO Joint Committee and FDA was remarkably effect on the sterilization of spices and superior in wholesomeness and economic feasibiity compared with traditional methods. Irradiation might be an alternative to traditional sterilization methods of spices by fumigants such as ethylene oxide and ethylene dibromide because their treatments have been banned in U.S.A and other countries since 1982.

• 한국발생생물학회지:발생과생식
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• 제23권3호
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• pp.199-211
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• 2019

The sterilization effects of methylene blue (MB), formalin, and iodine on the egg of marine medaka, Oryzias dancena, were investigated for disinfecting naididae worm, Chaetogaster diastrophus through sterilization. To determine harmfulness of MB, formalin, and iodine, lethal concentrations 50 ($LC_{50}$) of three chemicals were analyzed in the eggs of marine medaka. The sterilized periods of each chemical were set at 1 hr. Sterilized rates of naididae worm in each chemical were significantly affected and increased drastically as the concentration of each chemical increased (p<0.05). Sterilization abilities of naididae worm were most effective for formalin, but survival rates of egg and hatched rates for formalin were lowest among each chemical. The $LC_{50}$ of MB over 96 hrs were 185.26, 103.84, and 127.15 ppm for adults, juveniles, and eggs respectively. The toxic effects of MB were clearly dose dependent for each life stage (p<0.05). The toxicity sensitivity of juveniles to MB was dramatically higher than that of other groups. In 48 hrs after sterilization, cortisol and glucose concentrations of the adult group with MB treatment were significantly higher than those of the adult group with no treatment (p<0.05). This research provides useful data on sterilization effect of MB, formalin, and iodine, acute toxicity in marine medaka egg and toxicity, sensitivity of life stage of MB in marine medaka.

• 한국환경보건학회지
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• 제5권1호
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• pp.1-9
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• 1978

Biological safety, physico-chemical and microbiological experiments were carried out in order to study the possibility of radiation sterilization on medical products, such as polyethylene and polystyrene bottles, gauze sponges and surgical silk suture. Results are as follows: 1. Biological test on plastic samples as to acute systemic toxicity, eye irritation, skin irritation, pyrogen, haemolysis showed satisfactory results. But physico-chemically, the oxidizable matter, nonvolatile residues, residue on ignition seemed to be increased slightly in irradiated samples, though the experimental results were within the range of U.S.P. 19, N.F. and K.P. III. 2. After irradiation, both plastic and gauze sponges showed considerable decrease in pH. 3. Most medical products were sterilized by 1.5 Mard. For the sterilization of the suigical silk suture, 4.5 Mrad is required dul to its radiation resistant micro-organisms. 4. Biologically, total dose of 2.5 Mrad was safe enough to sterilize the medical products, and physico-chemically the results are acceptable according to U.S.P. 19 and K.P. III. However, better results may be expected when the quality of material and additives are improved.