• Journal of Preventive Medicine and Public Health
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• v.54 no.1
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• pp.31-36
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• 2021

Objectives: Non-traditional materials are used for mask construction to address personal protective equipment shortages during the coronavirus disease 2019 (COVID-19) pandemic. Reusable masks made from surgical sterilization wrap represent such an innovative approach with social media frequently referring to them as "N95 alternatives." This material was tested for particle filtration efficiency and breathability to clarify what role they might have in infection prevention and control. Methods: A heavyweight, double layer sterilization wrap was tested when new and after 2, 4, 6, and 10 autoclave sterilizing cycles and compared with an approved N95 respirator and a surgical mask via testing procedures using a sodium chloride aerosol for N95 efficiency testing similar to 42 CFR 84.181. Pressure testing to indicate breathability was also conducted. Results: The particle filtration efficiency for the sterilization wrap ranged between 58% to 66%, with similar performance when new and after sterilizing cycles. The N95 respirator and surgical mask performed at 95% and 68% respectively. Pressure drops for the sterilization wrap, N95 and surgical mask were 10.4 mmH2O, 5.9 mmH2O, and 5.1 mmH2O, respectively, well below the National Institute for Occupational Safety and Health limits of 35 mmH2O during initial inhalation and 25 mmH2O during initial exhalation. Conclusions: The sterilization wrap's particle filtration efficiency is much lower than a N95 respirator, but falls within the range of a surgical mask, with acceptable breathability. Performance testing of non-traditional mask materials is crucial to determine potential protection efficacy and for correcting misinterpretation propagated through popular media.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.2
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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.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.1
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• pp.45-52
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• 2015

Objectives To check marker content for appropriate quality control of Woohwangchungsimwon sterilized to ensure microbiological safety and to observe antioxidant activity for any changes in efficacy. Methods To measure any effects of sterilization on the effective compounds, 8 ingredients of Woohwangchungsimwon were screened for any changes in marker content using HPLC-DAD. Using the colorimetric method on the microplate reader any changes in total phenolic compound and flavonoid levels were observed. Antioxidant activity was measured using the DPPH, ABTS, and FRAP. Results Of the ingredients of Woohwangchungsimwon, 8 were subject to quantitative analysis before and after sterilization. 21.6 mg and 1.93 mg of Glycyrrhizin was found in Glycyrrhiza uralensis Fischer pre and post sterilization, respectively. Decursin found in Angelica gigas Nakai increased from 0.16 mg to 0.29 mg after sterilization. Bilirubin found in Gallstone of Bostaurusvar. domesticus increased from 0.24 mg to 0.33 mg. Cinnamic acid found in Cinnamomum cassia Blume increased from 0.02 mg to 0.05 mg. Ginsenoside Rb1 found in Panax ginseng C. A. Meyer decreased from 0.02 mg to 0.14 mg. Paeoniflorin found in Paeonia lactiflora Pallas increased from 1.05 mg to 1.13 mg. Amygdalin found in Armeniacae Amarum Semen increased from 2.68 mg to 2.83 mg. L-muscone found in Musk increased from 0.63 mg to 0.76 mg. As for total phenolic compound and total flavonoid content, there was a 1.22 and 4.15-fold increase. DPPH and ABTS increased by 20.45% and 20.69%, respectively. FRAP activity was 2.78 times more active post stabilization. Conclusions This study confirmed that high temperature high pressure steam sterilization, a method used to ensure microbiological safety of Woohwangchungsimwon, does not affect marker content; in other words, does not affect quality of the Woohwangchungsimwon. It could also be seen that total phenolic compound and flavonoid content increased after sterilization. An antioxidant activity test showed that there was significantly increased activity of antioxidants.

• Korean Journal of Pharmacognosy
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• v.36 no.3 s.142
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• pp.220-223
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• 2005

The purposes of this study was to develop the best one among the methods using dry heat, gamma irradiation and alcohol gas, to sterilize Scutellariae Radix selected based on high frequency of circulation between merchants and high susceptibility to microbial contamination, through comparing these methods in terms of the followings; ⅰ) the efficacy of sterilization in comparison with cost, and ⅱ)the alteration of chemical components of these herbal medicines. The results of this study will be taken advantage of establishment of the maximum limit of microorganism contaminated in herbal medicines. From the results of this study we conclude the followings: ⅰ) The sterilizing method using dry heat may be inappropriate, because it seriously changed their color and morphology which is an essential criterion to estimate a measure of quality between merchants and consumers, although it effectively got rid of contaminated microorganism and did not alter major components, baicalin; ⅱ) The sterilizing method using gamma irradiation may be appropriate, because it showed a strong sterilizing effect, and no alteration of chemical components, color and morphology; ⅲ)The sterilizing method using alcohol gas may also be appropriate, because it had a similar effects as in the case of gamma irradiation. Collectively, we suggest that appropriate sterilizing methods to guarantee the microbial quality of this herbal medicine may be those using gamma irradiation and alcohol gas.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.319-324
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• 2006

The purpose of this study Is to evaluate the efficacy of multizone simulation that enables to grasp of details about microbial contaminant problem in an multistoried apartment. We used actual indoor test data to figure up microbial contaminant level as initial value for the multizone simulation and estimated the various effects of indoor occupant infected with germs and the performance of air sterilization by using multizone simulation in substitute for infeasible experimental approach. The results show that natural ventilation make ourselves generally useful for removing indoor microbial contaminants. The results also show that the performance of air sterilization reach the maximum in the case of using mechanical ventilation and UVGI air sterilizer. The conclusion is that this multizone simulation is useful tool for actual design method for Immune building systems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.4
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• pp.291-298
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• 2007

The purpose of this study is to evaluate the efficacy of multizone simulation that enables to grasp of details about microbial contaminant problem in an multistoried apartment. We used actual indoor test data to figure up microbial contaminant level as initial value for the multizone simulation and estimated the various effects of indoor occupant infected with germs such as bacteria and fungus and the performance of air sterilization by using multizone simulation in substitute for infeasible experimental approach. The results show that natural ventilation make ourselves generally useful for removing indoor microbial contaminants. The results also show that the performance of air sterilization reach the maximum in the case of using mechanical ventilation and UVGI air sterilizer. The conclusion is that this multizone simulation is useful tool for actual design method for immune building systems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.912-917
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• 2011

The sterilization efficacies of various washing solutions on the surfaces of vegetables such as sesame leaves, lettuce, and mini-cabbage were investigated. The washing solutions were tap water (TW), microbubble water (MB), electrolyzed water (EW), and microbubble electrolyzed water (MB＋EW). After Escherichia coli and Bacillus cereus were artificially inoculated onto the surfaces of vegetables, each vegetable was washed for 1, 3, and 5 min with TW, MB, EW 100 (100 mg/L of available chlorine), EW 200 (200 mg/L of available chlorine), MB+EW 100, and MB＋EW 200. The washing efficacy of MB was slightly higher than that of TW, and EW was more effective than MB (p<0.05). In all instances, the sterilization efficacies of MB+EW 100 and MB+EW 200 were higher than those of EW 100 and EW 200 (p<0.05). Thus, MB+EW offers an effective means of reducing the studied microorganisms in a short time period. The MB＋EW washing method provides microbial reduction on the surfaces of various vegetables and enhances the microbiological safety of the vegetables.

• Journal of Oral Medicine and Pain
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• v.34 no.3
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• pp.237-245
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• 2009

The purpose of this study was to investigate the clinical efficacy of latex cover developed for dental handpiece on contamination of microorganisms during dental treatment and to determine whether it can be an alternative to conventional sterilization such as autoclaving. E. fecaelis was used as a experimental microorganism instead of oral flora. Experimental bowl with 2 cm of rectangular cavity was fabricated for handpiece operating instead of oral cavity. Latex covers ($Orokeeper^{(R)}$, Orobiotech Co., Korea) and several handpieces were used after sterilization by autoclave. Four experiments were performed to evaluate bacterial contamination related with (1) various parts of dental handpiece, (2) swabbing time with alcohol sponge, (3) postoperative air-water spraying time and (4) consecutive use of latex covers without autoclaving. The results show that face of handpiece uncovered with latex cover was severely contaminated than the covered area and that most bacteria were removed by swabbing face and head area of dental hand-piece and by air-water spraying more than 15 seconds nearly up to the level of sterilization. Conclusively it can be suggested that use of latex cover for handpiece during dental procedure, swabbing with alcohol sponge is air-water spraying for more than 15 seconds after use of dental handpiece should be very useful and practical for prevention of cross infection and should be an alternative method for the sterilization of dental handpiece under some difficult situations not being able to sterilize a handpiece with autoclave.

• Journal of Mushroom
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• v.19 no.3
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• pp.210-215
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• 2021

For sterilization of microorganisms of the Listeria genus contaminating enoki mushroom, pilot mushroom grower equipped with air sterilization devices were developed. Sterilization experiments were performed using physical and chemical treatments. Internal temperature and humidity were controlled, maintaining 6.62℃±0.30 in the upper shelves, 6.46℃±0.24 in the middle shelves, and 6.48℃±0.25 in the lower shelves. Humidities were 79.97%±4.42, 79.43%±4.06, and 79.94±4.30%, respectively, with a temperature setting of 6.5℃, and a relative humidity of 75%. A suitable enoki mushroom cultivation stage for air sterilizer application was during the growth stage, with temperature in the 6.5~8.5℃ range, and humidity of 70~80%. At these same internal conditions, the ozone concentration in the mushroom cultivator was found to be 160 ppb during ion-cluster generator operation. After physical sterilization, the Listeria innocua survival rate was 0.1 to 0.9% using ion cluster sterilization, and 9.3 to 10.6% using UV air sterilization. The Listeria innocua survival rates on different materials were 9.3~10.6% on the metal specimen, and 9.9~16.2% on the plastic wrapper. The survival rate was particularly high on the rough side of the plastic wrapper. Ion cluster air sterilization is a labor-saving and effective method for suppressing the occurrence of Listeria bacteria on mushroom growers walls and shelves. For the plastic wrapper, chemical sterilization is more effective than physical sterilization.

• YAKHAK HOEJI
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• v.49 no.2
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• pp.180-184
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• 2005

The purpose of this study was to develop the best methods to sterilize Moutan Root Bark which is frequently used as a herbal medicine, and known to have high susceptibility to m icrobial contamination. We used dry heat, gamma irradiation and alcohol gas treatment for sterilization, and evaluated these methods in terms of the followings; I) the efficacy of sterilization, and ii) the chemical alteration of a major component of the harbal medicines. Treatment with dry heat effectively got rid of contaminated microorganisms, and did not significantly alter the content of paeonol. However it seriously changed the color and morphology which are an essential criterion to estimate a measure of quality of medicinal herbs. Treatment with gamma irradiation showed a strong sterilizing effect, and no alteration of the content of paeonol, color and morphology. Alcohol gas treatment resulted in similar effects as those in gamma irradiation. Collectively, these results suggest that appropriate sterilizing methods to guarantee the microbial quality of this herbal medicine may be those using gamma irradiation or alcohol gas.