• Journal of Digital Convergence
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• v.11 no.12
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• pp.665-672
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• 2013

In radiology department, where patients with a variety of diseases receive their tests, there is a large possibility of cross contamination of nosocomial infection. Magnetic resonance imaging (MRI) tests take particularly more time than other tests do, which increases the possibility of being exposed to cross contamination. Therefore, this research examines the status of MRI equipment sterilization and investigates the bacterial distribution on head coils, which have the most frequent contact with patients, patient fixation blocks, and bores, which are confined spaces. The status of MRI equipment disinfection was examined by a survey targeting 150 employees, and the distribution of bacteria was measured in ten medical facilities. The result of bacterial distribution tests on MRI equipment showed various bacteria, including Staphylococcus, Acinetobacter, Sphingomona, Pantoea agglomeranss, Micrococcus, Bacillus, Saprophyticus, Brevundimona, and Myroidesspecies. The result of examining the stat us of MRI room disinfection showed that the disinfections of the head coil, block, and bore were implemented well, and the largest proportion was carried out once a day in the morning. The time and implementation of disinfection by the disinfection manager showed that they were implemented well when the manager was the MRI room examiner. The disinfection after examining a patient using an appropriate disinfectant is mandatory to prevent cross contamination.

• Journal of radiological science and technology
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• v.41 no.4
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• pp.297-304
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• 2018

This study proposes measures and methods to reduce healthcare associated infections by comparing and analyzing the bacterial contamination level before and after putting on personal protective equipment (PPE) on the test equipment and the contact infected patients getting chest PA projections. Among the 50 inpatients who were diagnosed with C. difficile, MRSA, and VRE, 28 patients who were instructed to undergo chest PA projection and follow-up were chosen, The 3 parts that come in contact with the detector, chin, chest, and hands, were designated for all, and the bacterial contamination level before and after disinfection and before and after putting PPE was determined. Statistical analysis was performed using Medcalc version 14, and quantitative analysis was performed using paired student t-test, with statistical significance being noted at p<0.05. Results for the comparison of the mean values before and after disinfection of the detector, chin (3.000), chest (2.000), and hands (3.430), showed that the number of bacteria after disinfection was lower than it was before disinfection. Analyzing for each part before and after disinfection, there were statistically significant differences for the chin, chest, and hands (p<0.01). Results for the comparison of the mean values before and after putting on PPE, chin (2.202), chest (2.140), and hands (4.213), showed that the number of bacteria after putting on PPE was lower than it was before putting on PPE. Analyzing for each part before and after putting on PPE, there were statistically significant differences for the chin, chest, and hands (p<0.03). As a result, it was confirmed that the number of bacteria after putting on PPE was lower than it was before putting it on. In the future, expanding the research scope for contact infected patients will establish standards for quarantine guidelines depending on the way it spreads, and contribute to the prevention of healthcare associated infections.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1653-1660
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• 2004

This study was conducted to investigate seasonal changes of microbiological counts and sanitation state on the surface of food service facilities and utilities of elementary schools in Busan area. Samples swabbed using sponge were collected from the surface of food service facilities and utilities, that is ceiling, wall, floor, trench, grease trap, hood, pest control net and dumb waiter, and analyzed by measuring the total plate, coliform and Salmonella spp. count. The total plate counts at foodservice facilities and utilities except ceiling and wall were ranged from 10$^4$∼10$^{6}$ CFU/100 $\textrm{cm}^2$. The coliform counts were ranged from 10$^2$∼10$^4$ CFU/100 $\textrm{cm}^2$ at foodservice facilities and utilities except ceiling. The grease trap was the severely contaminated facility. It was indicated that the sanitary condition at the foodservice facilities and utilities except ceiling and wall should be improved promptly. As a result of investigating the seasonal changes of microbiological counts, floor, trench, grease trap and dumb waiter should be carried out disinfection before foodserving everyday in summer season, and the disinfection frequencies of wall, hood and pest control net should not be less than three times per week. In winter season floor, trench, and dumb waiter should be carried out disinfection after foodserving, grease trap should be carried out disinfection before foodserving everyday and the disinfection frequencies of wall, hood and pest control net should not be less than twice per week.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.69-75
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• 2009

The characteristics of disinfection and organic removal were investigated with pulse UV lamp in this study. The intensity and emission wavelength of pulse UV Lamp were compared with low pressure UV lamp. The emission spectrum range of pulse UV lamp was between 200 and 400 nm while the emission spectrum of low pressure UV lamp was only single wavelength of 254nm. 3 Log inactivation rate of B. subtilis spore by pulse UV and low pressure UV irradiation was determined as $44.71mJ/cm^2$ and $57.7mJ/cm^2$, respectively. This results implied that wide range of emission spectrum is more effective compared to single wavelength emission at 254nm. 500ng/L of initial 2-MIB concentration was investigated on the removal efficiency by UV only and $UV/H_2O_2$ process. The removal efficiency of UV only process achieved approximately 80% at $8,600mJ/cm^2$ dose. 2-MIB removal rate of $UV/H_2O_2$ (5 mg/L $H_2O_2$) process was 25 times increased compared to UV only process. DOC removal efficiency for the water treatment plant effluent was examined. The removal efficiency of DOC by UV and $UV/H_2O_2$ was no more than 20%. Removal efficiency of THMFP(Trihalomethane Formation Potential), one of the chlorination disinfection by-products, is determined on the UV irradiation and $UV/H_2O_2$ process. Maximum removal efficiency of THMFP was approximately 23%. This result indicates that more stable chemical structures of NOM(Natural Organic Matter) than low molecule compounds such as 2-MIB, hydrogen peroxide and other pollutants affect low removal efficiency for UV photolysis. Consequently, pulse UV lamp is more efficient compared to low pressure lamp in terms of disinfection due to it's broad wavelength emission of UV. Additional effect of pulse UV is to take place the reactions of both direct photolysis to remove micro organics and disinfection simultaneously. It is also expected that hydrogen peroxide enable to enhance the oxidation efficiency on the pulse UV irradiation due to formation of OH radical.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.597-608
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• 2005

The aim of this study is to determine whether full-mouth disinfection therapy(FMT) in our clinical setting would show better improvement of clinical parameters than partial mouth disinfection therapy(PMT) in chronic periodontitis and aggressive periodontitis patients. Among 12 patients, 6 were treated FMT and other 6 were treated PMT. Clinical parameters were calculated 3 months and 6 months after initial therapy. 1. There were no statistically significant differences between FMT and PMT in the reduction rate of bleeding on probing after 3 months, 6 months 2. Initial probing depth was 4-6mm, the mean probing depth after 3 months was 2.2mm vs 2.5mm(FMT vs PMT), after 6 months was 2.4mm vs 2.8mm. This was significantly lower in the FMT groups. 3. Initial probing depth was ${\geqq}$ 7mm, the reduction rate of mean probing depth during first 3 months was 4.8mm vs 4.1mm(FMT vs PMT), and 3 to 6 months was 0.5mm vs 0.3mm. This was significantly larger in the FMT groups. 4. Initial probing depth was 4-6mm, the mean clinical attachment level after 3 months was 2.3mm vs 2.7mm(FMT vs PMT), after 6 months was 2.7mm vs 3.0mm. This was significantly lower in the FMT groups. 5. Initial probing depth was ${\geqq}$ 7mm, the reduction rate of mean probing depth during first 3 months was 4.0mm vs 3.0mm(FMT vs PMT), and 3 to 6 months was 0mm vs -0.1mm. This was significantly larger in the FMT groups. Although the results provided us with succeccful clinical improvement in aggressive periodontitis, further research is needed to prove its additional benefit in the treatment of chronic periodontitis

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.5
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• pp.505-512
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• 2021

A 3D model was developed to calculate the UV intensity of a submerged-type UV disinfection reactor. Numerical experiments were conducted by inputting the design factors of an open channel-type disinfection reactor and a pipe-type disinfection reactor that were installed in an actual sewage treatment plant. The following data were obtained: The average UV intensity of the installed open channel-type reactor and pipe-type reactor was 7.87 mW/cm² and 13.09 mW/cm², respectively; the UV dose reflecting the UV irradiation time and taking into account attenuation effects such as mixing imbalance, lamp aging, temperature, and fouling, was expected to be 21.1 mJ/cm² and 24.8 mJ/cm², respectively, and these values are 5 % and 24 % higher than the target UV dose of 20 mJ/cm², respectively. By using the UV3D model, the optimal lamp position, which maximizes the average UV intensity without changing the size of the disinfection reactor or lamp output power, can be found. In this case, by only adjusting the lamp position, the average UV intensity can be increased by 0.9 % for the open channel-type and 0.5 % for the pipe-type, respectively. A better average UV intensity can be obtained by model simulation. By adjusting the horizontal and vertical ratio of the open channel-type reactor and by moving the lamp position, the average UV intensity can be increased by 7.4 % more than the present case.

• The Korean Nurse
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• s.6
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• pp.97-100
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• 1963

• Journal of the Korean Dietetic Association
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• v.19 no.3
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• pp.209-222
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• 2013

This study examined the hygiene practices of contract foodservice employees and investigated the influence of education and work environment on these hygienes practices. A questionnaire was distributed to 250 contract foodservice employees and a total of 232 responses were received and analyzed. The overall score for hygiene practices of contract foodservice employees was 3.89 based on a 5-point scale. Cross-contamination was prominent (highest score at 4.46) and the heating temperature was less prominent (lowest score at 3.49). The factors most affecting contract foodservice employees were their work period, the size of the contract foodservice management company, the number of meals served daily, the frequency of meal service per day and the frequency of hygiene education. Compared to small and medium-sized contract foodservice management companies, the major contract foodservice management companies showed higher scores for refrigerator/freezer control (P<0.001), vegetable/fruit disinfection (P<0.001), thawing (P<0.001), heating temperature (P<0.001), cleaning/disinfection (P<0.01), and personal hygiene (P<0.05). The frequency of hygiene education had a significant effect on the performance levels for refrigerator/freezer control (P<0.001), vegetable/fruit disinfection (P<0.001), thawing (P<0.001), heating temperature (P<0.001), cleaning/disinfection control (P<0.001), food supply control (P<0.05), and personal hygiene (P<0.05). From these results, to increase the sanitation quality of contract foodservice operations, hygiene practice levels need to increase and hygiene education systematically should be enforced for foodservice employees.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.299-307
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• 2018

This study survey research of infection control, wastewater management, and instrument disinfection according to characteristic at Daegu, Gyeongbuk Province In 2012 and 2017, the same 114 dental clinics to identify the infection management behavior and prevent infection of dental medical institutions. Scored mean 3.37 points on 8 items of infection control, 95.5% in "records of the patient's medical history", 1.8% in "presence of a wastewater facility." Scored 94.7% in "disinfection of metal trays", 17.5% in "storage from a spitting receptacle in the waste bin and commissioned management.", Scored higher in of infection control, wastewater management and instrument disinfection according to general characteristics and dental characteristics in 2017 than in 2012. Points were higher dental hygienist, University graduation, Type of duty was counseling and management, hospital or higher, Number of dentist(dental hygienist, chair, patient) was high. Therefore raise a need for infection control into consideration the dental characteristics and education and promotion regardless of the hospital size.

• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.182-187
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• 2017

PURPOSE. Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. MATERIALS AND METHODS. 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at ${\alpha}=0.05$. RESULTS. The discs mean contraction was below 0.5% at all test times ranging from $0.200{\pm}0.014$ to $0.325{\pm}0.007$. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups (P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. CONCLUSION. The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks.