• 대한치과보철학회지
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• 제44권3호
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• pp.284-294
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• 2006

Statement of problem. Proliferation of Candida albicans is primarily within the plaque on the fitting surface of the denture rather than on the inflamed mucosa. Consequently, the treatment of the denture is equally important as treatment of the tissue. Cleansing and disinfection should be efficiently carried-out as the organisms can penetrate into the voids of the acrylic resin and grow in them, from which they can continue to infect and reinfect bearing tissues. Purpose. The purpose of this study was to evaluate the applicability of photocatalytic reaction to eliminate Candida albicans from acrylic resin denture base, and to investigate the anti-fungal effect with various UVA illumination time. Materials and Methods. The specimens were cured by the conventional method following the manufacturer's instruction using thermal polymerized denture base resin (Vertex RS: Dentimex, Netherlands). $TiO_2$ photocatalyst sol(LT), which is able to be coated at normal temperature, was made from the Ti-alkoxide progenitor. The XRD patterns, TEM images and nitrogen absorption ability of the $TiO_2$ photocatalyst sol(LT) were compared with the commercial $TiO_2$ photocatalyst P-25. The experimental specimens were coated with the mixture of the $TiO_2$ photocatalyst sol(LT) and binder material (silane) using dip-coater, and uncoated resin plates were used as the control group. Crystallinity of $TiO_2$ of the specimen was tested by the XRD. Size, shape and chemical compositions were also analyzed using the FE-SEM/ EDS. The angle and methylene blue degradation efsciency were measured for evaluating the photocatalytic activity of the $TiO_2$ film. Finally, the antifungal activity of the specimen was tested. Candida albicans KCTC 7629(1 ml, initial concentration $10^5$ cells/ ml) were applied to the experiment and control group specimens and subsequently two UVA light source with 10W, 353 nm peak emission were illuminated to the specimens from 15cm above. The extracted $2{\mu}l$ of sample was plated on nutrient agar plate ($Bacto^{TM}$ Brain Heart Infusion; BD, USA) with 10 minute intervals for 120 minute, respectively. It was incubated for 24 hours at $37^{\circ}C$ and the colony forming units (CFUs) were then counted. Results. Compared the characteristics of LT photocatalyst with commercial P-25 photocatalyst, LT were shown higher activity than P-25. The LT coated experimental specimen surface had anatase crystal form, less than 20 nm of particle size and wide specific surface area. To evaluate the photocatalytic activity of specimens, methylene blue degradation reaction were used and about 5% of degradation rate were measured after 2 hours. The average contact angle was less than $20^{\circ}$ indicating that the LT photocatalyst had hydrophilicity. In the antifungal activity test for Candida albicans, 0% survival rate were measured within 30 minute after irradiation of UVA light. Conclusion. From the results reported above, it is concluded that the UVA-LT photocatalytic reaction have an antifungal effect on the denture surface Candida albicans, and so that could be applicable to the clinical use as a cleaning method.

• 구강회복응용과학지
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• 제35권1호
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• pp.27-36
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• 2019

목적: 치과 치료에 사용되는 일부 비위험 기구들에 대한 치과의사의 감염 관리 인지도와 감염 관리 실태를 조사하고자 하였다. 연구 재료 및 방법: 대전광역시, 충청남도, 충청북도 및 전라북도 지역의 40개 치과 병, 의원을 연구 대상으로 하였다. 감염 관리에 대한 치과의사의 인지도와 실천정도에 관해서 설문 조사를 시행하였고, 연구 대상인 치과의사가 치과 치료에 사용하는 인상용 건, 광중합기, 3-way syringe, 색조 견본, 치실통의 표면 오염도를 아데노신 3인산 측정기를 이용하여 측정하였고, 감염 관리에 대한 인식도와 실태 간의 상관관계를 분석하였다. 결과: 감염 관리에 관한 인지도와 시행 빈도는 3-way syringe에서 가장 높았다. 모든 기구에서 소독액을 사용한 표면 소독이 가장 많이 시행되었다. 표면 오염도는 3-way syringe, 색조 견본이 인상용 건, 광중합기, 치실통보다 낮게 나타났다. 결론: 치과 치료에 사용되는 비위험 기구들 중에서 3-way syringe는 사용자의 감염 관리 인지도와 표면 오염도 간에 유의한 상관관계가 있으며, 감염 관리의 인지도가 높을수록 표면 오염도가 낮은 것으로 나타났다.

• 대한환경공학회지
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• 제34권11호
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• pp.729-734
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• 2012

용존유기질소(DON)는 염소와 반응하여 인체에 유해한 질소계 소독부산물과 소독능을 저하시키는 유기성 클로라민을 생성할 수 있다. 이러한 물질의 생성을 줄이기 위해서는 소독공정 전에 DON의 제거가 필요하다. 본 연구는 DON을 함유하는 지표수와 재이용수를 이용하여 응집실험을 하고 알루미늄염(alum)과 고분자응집제(polyDADMAC)에 의한 DON의 제거특성을 조사하였다. 또한 DON, 용존유기탄소(DOC), 254 nm 자외선 흡광물질($UVA_{254}$)의 제거율 및 제거 기작을 비교하였다. 지표수와 재이용수 모두 alum 응집제의 주입농도를 증가시킴에 따라 DON, DOC, $UVA_{254}$ 제거율이 점진적으로 증가하였는데, 원수특성과 상관없이 소수성 유기물을 나타내는 척도인 $UVA_{254}$의 제거율이 가장 높았다. 지표수와 재이용수 모두 alum 응집제만 주입한 경우보다 고분자응집제를 같이 주입한 경우 DON의 제거율이 높게 나타났다. 고분자응집제의 전하중화가 작용하는 적정농도범위가 좁아 고분자응집제만 주입하기 보다는 무기응집제와 같이 주입하는 하는 것이 바람직하다. 상대적으로 생성된 후 오랜 시간이 지나지 않은 재이용수의 DON 제거율이 지표수의 DON 제거율보다 높았고, 지표수와 재이용수 모두 10,000 Da 이상 분자량의 DON 제거율이 높게 나타났다.

• 한국치위생학회지
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• 제10권5호
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• pp.935-945
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• 2010

Objectives : The purpose of this study was to examine the knowledge of dental hygienists on infection control in dental office and their attitude toward that in a bid to provide some information on ways of enhancing the level of infection control in dental office. Methods : The subjects in this study were 220 dental hygienists who worked in dental hospitals and clinics in Busan and South Gyeongsang Province. A survey was conducted from May 17 to June 17, 2010, and the answer sheets from 183 respondents were analyzed with a SPSS WIN 12.0 program. Statistical data on frequency, percentage and mean were obtained, and t-test, Pearson correlation coefficient and one-way ANOVA were utilized. Results : They got a mean of $4.59{\pm}.68$ in six categories of infection control knowledge. They had the best knowledge on dental waste disposal, followed by hand washing, post-sterilization management, instrument disinfection and sterilization, surface management of dental equipment and wearing personal protective equipment. They got a mean of $3.99{\pm}.54$ in attitude, and they scored lowest in practice of surface management of dental equipment. Overall, they scored higher in every aspect of knowledge than in attitude(t=11.410, p=.0.000). There was the greatest gap between their knowledge and practice in surface management of dental equipment (t=13.885, p=0.000), and there was the smallest gap between their knowledge and practice in hand washing(t=5.460, p=0.000). And a positive correlation was found between knowledge and attitude, as better knowledge of infection control led to better attitude toward that(p<.001). Finally, concerning infection control knowledge and attitude by general characteristics, the presence or absence of infection control guidelines made differences to infection control knowledge, and infection control attitude was statistically significantly different according to infection control education experiences(t=6.501, p=.012) and the presence or absence of infection control guidelines(t=22.836, p=.000). Conclusions : In order to bolster infection control in dental office, the related system should be improved to legally require dental personnels to implement infection control. Every dental office must be furnished with infection control guidelines, and sustained education should be provided for dental hygienists to carry out infection control.

• 융합신호처리학회논문지
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• 제16권3호
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• pp.108-114
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• 2015

선박의 평형과 균형을 위해 사용하고 있는 선박용 평형수는 선박의 이동과 함께 이동되며 선박의 화물 적재와 하역 시 선박용 평형수의 급수와 배수가 이루어지게 된다. 이를 통하여 유입된 외래 해양 미생물의 경우 새로운 환경에 적응하여 스스로 파괴되기도 하지만 적응을 하게 되는 미생물의 경우에는 강력한 번식력을 바탕으로 해양 생태계를 파괴하게 된다. 주로 사용되고 있는 자외선 살균 공법은 살균된 미생물의 기형변이 문제와 침전물 제거, 2차 평형수 저장 탱크의 살균 문제를 가지고 있다. 이에 본 논문에서는 퍼지 PID제어 기법을 이용한 램프 출력 조절 시스템을 구현하여 램프 파손 방지와 미생물 기형변이 문제를 억제할 수 있는 선박평형수 처리시스템을 개발 하였다. 실험 결과 초기 3분간은 해수의 급격한 온도 상승이 이루어졌으며 안정기 이후에서는 적정 온도를 유지하여 램프의 수명 연장과 해양 미생물의 기형변이 문제를 억제 할 수 있게 되었다.

• 상하수도학회지
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• 제26권2호
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• pp.237-247
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• 2012

This study assessed the removal characteristics of taste and odor causing compounds (2-methylisoborneol and geosmin) and organic matters, using a pilot-scale ozone/granular activated carbon ($O_{3}$/GAC) process treating surface water of Pal-dang reservoir in the Han river over a 3-month period. Experiments were conducted to verify the removal efficiency of $O_{3}$/GAC process which has two different empty bed contact time (EBCT) ($O_{3}$/GAC column 1 : 10 min and 2 : 15.1 min) with 10.86 min contact time of ozonation at 1.0 mg/L $O_{3}$. Spiking test using geosmin and 2-MIB was also conducted systematically to mimic the conditions when the algae appears, specifically at the levels similar to the concentrations experienced (geosmin: 250 ng/L) in the winter of 2011. In single ozonation process, organic materials, disinfection by-products (DBPs) and their precursors were disassembled but not removed completely. Meanwhile, it was verified that organic matters, taste and odor causing compounds, and DBPs were well removed when sequentially passing through the GAC process. The pilot results also showed that GAC column with larger EBCT achieved higher removal efficiency. Specifically, in spiking tests, single $O_{3}$ process showed approximately 89% removal efficiency of geosmin and 2-MIB. $O_{3}$/GAC combined process demonstrated excellent removal of geosmin and 2-MIB, which are higher than 95%.

• 치위생과학회지
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• 제7권4호
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• pp.263-269
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• 2007

치과진료실에서의 감염방지 실태를 분석하여 향후 치과진료실에서의 감염방지 수준을 향상시키기 위한 방안을 제시하고자 대구광역시 소재 치과 병 의원에 근무하는 치과의사 50명, 치과위생사 176명, 간호조무사 100명을 대상으로 감염방지 교육 및 감염성 관리 실태를 분석한 결과는 다음과 같다. 1. 건강검진 실시율은 치과의사가 가장 높았고, 예방접종 실시율은 치과위생사가 가장 높았다. 2. 감염방지 교육 경험률은 치과의사가 가장 높았고, 간호조무사가 가장 낮았다(P < 0.05). 3. 개인용 보호장비 착용률은 치과의사가 가장 높았고, 간호조무사가 가장 낮았다(P < 0.05). 4. 진료 후 손 세척 시행률은 치과의사가 가장 높게 나타났다(P < 0.05). 5. 기구의 멸균 및 소독 시행률은 치과위생사가 다른 두 집단에 비해 높았다. 6. 장비의 표면 소독은 진료용 선반 위주로 시행하고 있는 것으로 나타났으며, 치과위생사 의 실천률이 높았다.

• 한국조리학회지
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• 제15권4호
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• pp.9-17
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• 2009

광주 지역 하절기 동안 일식 레스토랑 10곳의 위생 평가를 위해 미생물 검사를 실시하였다. 일식 레스토랑의 설비 및 조리기구 표면에서 swab sampling 방법으로 스폰지로 200개의 도말 표본을 채취하였다. 총 균수, 대장균군, 대장균, 포도상구균, 살모네라균, 리스테리아균을 측정하였다. 그 결과, 대부분의 도말 표본이 미생물과 대장균군으로 오염된 것으로 입증되었다. 오염 정도는 샘플 채취 장소에 따라 달랐다. 심하게 오염된 곳은 바닥, 트렌치, 생선 취급 코너였고, 이러한 표본의 총 균수는 $10^4$ CFU/100 $cm^2$이 넘었다. 바닥, 트렌치, 나무 도마의 대장균군은 $10^3$ CFU/100 $cm^2$이 넘었다. 게다가 대장균군은 행주, 식기, 그리고 생선 및 채소 코너에서도 검출되었다. 대장균은 몇몇 식당의 바닥과 트렌치에서 검출되었다. 포도상구균은 몇몇 식당의 도마, 행주, 바닥, 트렌치에서 발견되었다. 살모넬라균과 리스테리아균은 모든 표본에서 검출되지 않았다. 이러한 결과는 일식 레스토랑에서 위생관리와 소독이 필요함을 보여준다.

• 대한치과보철학회지
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• 제33권3호
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• pp.453-466
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• 1995

The use of tissue conditioners has come into favor for preprosthetic treatment and the treatment of Denture stomatitis, but the major problem in the use of the tissue conditioner is the growth of C.albicans. To compare the growth of C.albicans according to the type and the wearing period of the tissue conditioner, three commercial tissue conditioners were relined to intraoral plates which were delivered to 14 smoking, 12 nonsmoking healthy men. Cultures were made from the conditioner surface at 2, 7, 14, 21 days after after intraoral placement. The frequency of positive culture and colony counts of C.albicans were measured by imprint culture technique. The following results were achieved : 1. The frequency of positive cluture had increased significantly for all materials used. 2. The frequency of positive culture had incresed significantly around 2,14 days for day for COE-Comfort, SR-Ivoseal. 3. There were no significant difference in the colony counts of C.albicans among the mate rials used. 4. There were an over-all increase with the wearing period of tissue conditioners and significant increase around 2, 7, 14 days for COE-Comfort, and 2, 14 days for SR-Ivoseal, viscogel in colony counts. 5. Smoking had no effect on the growth of C.albicans. That is, there were no difference among the materials used in the growth of C.albicans. In the clinical application of tissue conditioners, we should avoid a long term use of it, but in inevitable cases, special disinfection procedures should be considered.

• 한국환경보건학회지
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• 제46권5호
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• pp.599-609
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• 2020

Objectives: Coronavirus disease 2019 (COVID-19) first emerged in December 2019 in Wuhan, China, and has rapidly become a global pandemic with over 26.4 million confirmed cases and approximately 871,000 fatalities worldwide as of this writing. In the Republic of Korea, disease clusters frequently occurred in long-term care hospitals where the majority of residents are elderly with underlying medical conditions. Despite the fact that public health authorities and local community health centers have put tremendous efforts into preventing the spread of disease, positive cases have continued to occur. Thus, the Korea Centers for Disease Control & Prevention rapid response team decided to conduct an environmental investigation of a long-term care hospital to identify whether environmental contamination has remained and contributed to the spread of COVID-19. Methods: An environmental investigation was conducted at Hospital A. The characteristics of the facility and its HVAC system were assessed by checking the layout and interviewing the people in charge. A total of 64 surface samples were collected from areas of concern, including patient rooms, toilets, elevators, and nurses' station. These samples were tested by a regional health and environmental research institute using real-time reverse transcription polymerase chain reaction. Results: All samples from Hospital A were confirmed to be negative. Through interviews with high-level personnel at the regional community health center, we found that extensive disinfection is frequently performed on potentially contaminated areas in Hospital A in accordance with government guidelines. Conclusion: The environmental control measures implemented in Hospital A had been sufficient for mitigating the risk of further infection, suggesting that such measures may also be effective for other long-term health care facilities.