• Clinical Endoscopy
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• 제55권1호
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• pp.33-40
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• 2022

Background/Aims: Multiple outbreaks of multidrug-resistant organisms have been reported worldwide due to contaminated duodenoscopes. In 2015, the United States Food and Drug Administration recommended the following supplemental enhanced surveillance and reprocessing techniques (ESRT) to improve duodenoscope disinfection: (1) microbiological culture, (2) ethylene oxide sterilization, (3) liquid chemical sterilant processing system, and (4) double high-level disinfection. A systematic review and meta-analysis was performed to assess the impact of ESRT on the contamination rates. Methods: A thorough and systematic search was performed across several databases and conference proceedings from inception until January 2021, and all studies reporting the effectiveness of various ESRTs were identified. The pooled contamination rates of post-ESRT duodenoscopes were estimated using the random effects model. Results: A total of seven studies using various ESRTs were incorporated in the analysis, which included a total of 9,084 post-ESRT duodenoscope cultures. The pooled contamination rate of the post-ESRT duodenoscope was 5% (95% confidence interval [CI]: 2.3%-10.8%, inconsistency index [I²]=97.97%). Pooled contamination rates for high-risk organisms were 0.8% (95% CI: 0.2%-2.7%, I²=94.96). Conclusions: While ESRT may improve the disinfection process, a post-ESRT contamination rate of 5% is not negligible. Ongoing efforts to mitigate the rate of contamination by improving disinfection techniques and innovations in duodenoscope design to improve safety are warranted.

• Clinical and Experimental Reproductive Medicine
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• 제21권2호
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• pp.221-226
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• 1994

Copper T 380A intrauterine devices were inserted to nine thousand and nine hundred twenty women by 51 KAVS-member physicians since January 1, 1993 through December 31, 1993. This study was undertaken for the clinical analysis on a total of 9,920 women wearing Copper T 380A to grasp the effectivness as well as the expulsion rate due to a various side effects. The following features were the results of the study: 1. During the twelve months period, from January 1993 to December 1993, the largest number of IUD insertion per one physician is 740 cases and the smallest number 60 cases, the mean 195 cases. 2. After insertion of Copper T 380A, a total of 117 cases were removed the IUD;81 cases(0.8%) were due to extensive bleeding and 36 cases(O.36%) were due to pain. The pregnancy failure rate represented comparatively lower rate, 0.08% (8 cases) and the expulsion rate was 0.06%(6 cases). 3. The removal rate of Copper T 380A was different by physicians. The highest removal rate for bleeding was 3.13% and 13 physicians(25.5%) did not experience any bleeding cases. 4. For the removal rate for pain, 30 physicians(58.8%) did not experience any removal of IUD due to pain while 21 physicians(41.2%) removed IUD due to pain: 17 physiciansC33.4 %) had 0.1-1.5% of removal rate and 4 physiciansC7.0%) had 1.6-2.1% of removal rate. 5. A total of 43 physicians(84.3 %) did not experience any pregnancy failure case while 8 (15.7%) physicians was experienced pregnancy failure rate. Four physicians(7.8%) had 0.1-0.5% of pregnancy failure rate and 4 physicians had 0.6-1.0% of pregnancy failure rate. 6. Expulsion rate showed comparatively lower, 0.06% in this study. A total of 45 physicians (88.2%) did not experience any expulsion cases while 6 physicians(11.7%) had expulsion rate with the highest expulsion rate of 2.0%.

• 한국식품위생안전성학회지
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• 제32권3호
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• pp.222-227
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• 2017

연구는 대기압 유전체장벽방전 플라즈마 처리에 따른 식품유해 미생물 사멸효과를 조사하기 위해 수행되었다. 플라즈마 처리 시, 활성종 생성 및 농도에 영향을 미치는 노출시간, 노출거리, 산소비율, 전력 변화에 따른 E. coli의 사멸효과를 조사한 결과, E. coli의 사멸율은 플라즈마 처리를 위한 노출시간, 산소비율, 전력의 증가에 따라 증가한 반면, 노출거리의 증가에 따라서는 사멸율이 감소하였다. 이 결과는 미생물 시료가 플라즈마에 노출되는 시간이 증가됨으로서 시료 내 NO 농도가 증가되고, E. coli의 사멸율 역시 증가되는 결과로 뒷받침할 수 있고, 미생물 사멸효과를 높이기 위해서는 활성종의 농도가 증가되어야 함을 의미한다. E. coli와 함께 B. cereus, B. subtilis, B. thuringiensis, B. atrophaeus를 대상으로 대기압 유전체 장벽방전 플라즈마에 의한 살균효과를 조사한 결과, 72.3~91.3%의 높은 사멸율을 나타내었다. 이러한 결과로 미루어, 대기압 유전체장벽방전 플라즈마기술은 다양한 미생물에 적용될 수 있는 유용한 살균기술임을 확인하였다.

• 한국미생물·생명공학회지
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• 제9권4호
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• pp.231-236
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• 1981

성홍열, 단독, 패혈증의 원인균인 Streptococcus pyogenes중에서 항암효과가 좋은 균주를 선정하여 항암제 생산을 위한 기초실험으로서 열 처리에 따른 적정 살균조건을 검토하여 다음과 같은 결과를 얻었다. Streptococcus pyogenes의 생육 최적온도는 37$^{\circ}C$이었고 대수기에서 평균 세대시간은 20분이었으며, 5$0^{\circ}C$ 이상으로 열 처리하면 생존균이 감소하였다. 균 현탁액을 pH6, 7, 8, 9로 조절한 후, 5$0^{\circ}C$에서 열 처리하였을 때는 대수적으로 사멸하였고, 사멸속도상수 k값은 각각 0.1448, 0.1194, 0.1273, 0.1707(min.$^{-1}$)이었으나 60, 70, 80, 9$0^{\circ}C$로 열 처리하면 10분만에 99%이상이 사멸되었으며 10$0^{\circ}C$에서는 완전히 사멸되었다.

• Clinical and Experimental Reproductive Medicine
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• 제28권4호
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• pp.307-315
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• 2001

Objective: To evaluate the clinical outcomes and influencing factors of in vitro fertilization and embryo transfer (IVF-ET) in patients with failed pregnancy after microsurgical reversal of tubal sterilization. Materials and Methods : From January, 1997 to December, 2000, IVF-ET was performed in two groups; the study TR (tubal reanastomosis) group consisted of 147 cycles in 66 patients with failed microsurgical reversal of tubal sterilization, and the control group of 115 cycles in 67 patients with bilateral tubal occlusion (BTO). The two groups were evaluated and compared for clinical characteristics, clinical pregnancy rates, and factors influencing the outcomes of IVF-ET. Results: Compared with the control BTO group, age and the previous parity were significantly higher ($36.3{\pm}2.7$ vs. $33.6{\pm}2.0$ years, p<0.05; $1.6{\pm}0.7$ vs. $0.2{\pm}0.4$, p<0.05), and the clinical pregnancy rate per cycle was significantly lower (23.8% (35/147) vs. 29.3% (34/115), p<0.05) in the TR group. Difference in the clinical pregnancy rates was age-related, since there was no significant difference between the two groups, except for the previous parity ($1.6{\pm}0.7$ vs. $0.1{\pm}0.3$, p<0.05), when the patients aged 37 years or older were excluded. No difference was found in terms of the following: the proportion of controlled ovarian hyperstimulation (COH) cycles with GnRH agonist ultrashort protocol, the duration of COH, the dosage of gonadotropins used, and the numbers of oocytes retrieved and of embryos transferred, irrespective of age correction. Conclusions: The outcomes of IVF-ET following the failed microsurgical reversal of tubal sterilization depend upon patient age. The previous fertility of patients does not seem to be a factor of better IVF-ET prognosis.

• 전기학회논문지
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• 제58권3호
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• pp.559-565
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• 2009

In this paper, we invented a new and unique technique for the sterilization of Escherichia coli(E. coli) in polluted water. We applied a rich ultra-violet(UV) light from pulsed xenon flashlamp and photocatalyst(TiO2) to sterilize E. coli in polluted water. This method based on the use of UV light and photocatalyst is eco-friendly and does not cause secondary pollution. The proposed elliptical reactor is able to concentrate on quartz sleeve coated TiO2 or general quartz sleeve. The primary objective of our research was to determine the important parameters such as pulse repetition rate and input voltage and to know on the sterilizing efficiency of quartz sleeve coated TiO2 and general quartz sleeve. We obtained to achieve 99.999% sterilization in as little as 6 pulses at 800V in case of quartz sleeve coated Ti02, and 10 pulses at 800V in case of general quartz sleeve for 5 minutes. Although transmitted light of quartz sleeve coated TiO2 is deceased, the sterilizing efficiency is increased by 40% than general quartz sleeve. The reason of high sterilizing efficiency is that generated hydroxyl radical(OH) by photocatalyst and is able to concentrate light at a focus by using elliptical reactor.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.227-232
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• 2004

선박에서 발생되는 밸러스트수를 처리하기 위하여 수중에 포함되어 있는 미생물을 북극전해처리시스템을 이용하여 살균처리 하였다. 전해처리시스템에 유입되는 시료는 정량펌프를 사용하여 상향류로 전극판 사이를 통과하도록 하였으며, 반응시간별로 유량을 조절하여 체류시간을 다르게 하였다. 양극판은 티타늄에 이산화이리듐을 전착한 Ti／IrO$_2$ 극판으로 하였으며, 음극판은 스테인리스 스틸판을 사용하였다. 전원공급은 최대 전압이 250V, 전류가 100Amper의 맥류가 전혀 없는 트랜지스트 평활회로를 사용한 D.C. Power Supply를 사용하여 전류밀도를 조절하여 운전하였다. 반응시간에 따라 전류밀도를 0.1~l.0A사이로 변화를 주어 실험한 결과 5초 이내에 대부분의 미생물이 사멸됨을 확인 할 수 있었고 연구결과를 통하여 발라스트수 처리에 적용 가능한 기술임을 알 수 있었다.

• Current Optics and Photonics
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• 제6권2호
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• pp.202-211
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• 2022

In the pasteurization of escalator handrails using ultraviolet (UV) sterilizers, a combination of light distribution and escalator speed has priority over other important factors. Furthermore, since part of the escalator handrail has a curved structure, proper design is needed to improve the sterilization rate on the surfaces touched by users. In this paper, two types of sterilizers satisfying these conditions are manufactured with 275-nm UV-C LEDs, after modeling the three-dimensional (3D) structure of an escalator handrail and simulating optical distributions of UV-C irradiation on the handrail's surface according to light-emitting diode (LED) positions and reflector variations in the sterilizers. Pasteurization experiments with the UV-C LED sterilizers are conducted on six types of gram-positive and gram-negative bacteria, with exposure times of 0.2, 5, and 15 s at an actual installation distance of 20 mm. The sterilization rates for the gram-positive bacteria are 10.63% to 27.94% at 0.2 s, 89.44% to 96.30% at 5 s, and 99.64% to 99.88% at 15 s. Those for the gram-negative bacteria are 57.70% to 77.63% at 0.2 s, 98.90% to 99.49% at 5 s, and 99.88% to 99.99% at 15 s. The power consumption of the UV-C LED sterilizer is about 8 W, which can be supplied by a self-generation module instead of an external power supply.

• 한국버섯학회지
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• 제13권3호
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• pp.256-261
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• 2015

병재배 느타리버섯 재배과정중 발생되는 유해균 감소를 위한 적합 배지 살균조건과 UV-C 조사결과는 다음과 같다. 살균조건에 따른 오염율 및 전력소비량을 측정한 결과, $121^{\circ}C$에서 90분 살균시 오염율 0%, 전력소비량 4.1 kwh로 가장 낮게 조사되었다. 살균 후 배지 미생물상은 $121^{\circ}C$에서 90분, $109^{\circ}C$에서 2, 4, 6시간, $105^{\circ}C$에서 6시간, $101^{\circ}C$에서 6시간 살균시 버섯유해 곰팡이인 Trichoderma sp.가 검출되지 않았다. 또한, 버섯재배사의 냉각실과 접종실에 UV-C 처리에 의한 미생물의 사멸율을 조사한 결과, $56m^3$의 규모에서 40w짜리 UV-C를 6시간 조사했을 때 세균(Staphylococcus sp.) 사멸율은 99.9%로 거의 검출되지 않았다. 푸른곰팡이류중 가장 큰 오염원인 Trichoderma sp.와 Penicillium sp. 도 UV-C 6시간 조사 시 99.9% 사멸되었고, Cladosporium sp.는 동일 조건에서 90.9% 사멸되었으며 UV-C 12시간 조사시 94.9%의 사멸율을 보였다. 따라서 멸균 조건에 따른 오염율, 전력소비량, 미생물상 등을 종합해볼 때 $121^{\circ}C$에서 90분 고압살균하는 방법이 병재배에서는 적합하다고 판단되었으며, 버섯배양시 발생되는 주요 유해균은 UV-C 6시간 이상 점등 처리시 사멸율이 높았다.

• 한국산업보건학회지
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• 제31권2호
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• pp.138-146
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• 2021

Objectives: This study aims to compare and evaluate the reduction efficiency of disinfectants used in the domestic meat processing industry to reduce bioaerosol exposure of meat industry workers and to use this as basic data for establishing work environment management measures. Methods: Thirteen disinfectants sold in South Korea were selected for evaluation and the bacterial reduction effect of the disinfectants was investigated. Bacterial suspension and surface disinfection tests were conducted to compare and analyze the antibacterial strength of the disinfectants. Pork carcasses, cutting boards, benches, and conveyor belts were selected for surface sterilization tests. Results: As a result of the bacterial suspension experiment test, all disinfectants had a bacterial reduction efficiency of more than 86%. Among them, the bacterial reduction efficiency of chlorine disinfectants was 99.93% on average. In the results of the pork carcass surface sterilization test, the rate of reduction of disinfectants made of quaternary ammonium compounds (QACs) was the highest. Tests of plastic cutting boards showed that chlorine disinfectants had the best sterilization effect. Experiments on stainless steel benches showed the best bacterial reduction efficiency for chlorine dioxide and QACs disinfectants. In the conveyor belt made of urethane, QACs disinfectants showed excellent sterilization effects. Conclusions: The study evaluated the disinfection power of disinfectants against bacteria occurring in domestic meat processing plants. All disinfectants were found to be effective in bacterial suspension experiments, and chlorine disinfectants were particularly effective. In surface sterilization experiments, sterilizing agents with QACs as the main ingredient were excellent.