• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.12.1-12.9
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• 2020

Coronavirus is an enveloped virus with positive-sense single-stranded RNA. Coronavirus infection in humans mainly affects the upper respiratory tract and to a lesser extent the gastrointestinal tract. Clinical symptoms of coronavirus infections can range from relatively mild (similar to the common cold) to severe (bronchitis, pneumonia, and renal involvement). The disease caused by the 2019 novel coronavirus (2019-nCoV) was called Covid-19 by the World Health Organization in February 2020. Face-to-face communication and consistent exposure to body fluids such as blood and saliva predispose dental care workers at serious risk for 2019-nCoV infection. As demonstrated by the recent coronavirus outbreak, information is not enough. During dental practice, blood and saliva can be scattered. Accordingly, dental practice can be a potential risk for dental staff, and there is a high risk of cross-infection. This article addresses all information collected to date on the virus, in accordance with the guidelines of international health care institutions, and provides a comprehensive protocol for managing possible exposure to patients or those suspected of having coronavirus.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.127-131
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• 2014

While searching for lactic acid bacteria that can restore aging-impaired immune responses, we isolated the Toll-like receptor (TLR) 2/NF-${\kappa}B$-activating strain Lactobacillus plantarum HY7712 from kimchi and investigated its immunomodulating effect in whole-body ${\gamma}$-irradiated mice. Exposure to HY7712 strongly activated NF-${\kappa}B$ signaling in RAW264.7 cells, but inhibited lipopolysaccharide-stimulated NF-${\kappa}B$ activation. Moreover, HY7712 protected against the downregulation of interferon (IFN)-${\gamma}$ and upregulation of interleukin (IL)-13 caused by ${\gamma}$-irradiation in mice. In mice, ${\gamma}$-irradiation impaired NK-cell activity against YAC-1 tumor cells, but following HY7712 exposure, the activity of NK cells was restored to 91.5% of the level measured in control mice (p < 0.05). These findings suggest that HY7712 activates the TLR2/NF-${\kappa}B$ signaling pathway and protects against the impairment of NK-cell activity caused by ${\gamma}$-irradiation or aging.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.396-401
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• 2014

Nanomaterials have been widely used in many fields. This study investigates the effects of metal oxide nanoparticles (CuO, NiO, $TiO_2$, $Fe_2O_3$, $Co_3O_4$, ZnO) on germination and germination index (G.I.) of seeds, Lactuca and Raphanus. Under aqueous exposure, CuO on Lactuca shows the most significant impacts on activities compared to others, showing $EC_{50s}$ for germination and G.I. as 0.46 mg/L and 0.37%, respectively. The effects of nanoparticle phytotoxicity on seed Lactuca was much higher than that of Raphanus. In general, the toxicities on seed germination and germination index were as following orders : CuO > ZnO > NiO ${\gg}$ $TiO_2$, $Fe_2O_3$, $Co_3O_4$. No measurable inhibition was observed at 1,000 mg/L (maximum exposure concentration) of $TiO_2$, $Fe_2O_3$, $Co_3O_4$.

• Journal of Radiation Protection and Research
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• v.18 no.1
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• pp.71-82
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• 1993

It is a fundamental element of the nuclear power plant operation to assess exactly the occupational radiation exposure. And, according to recently published ICRP 60 recommendation, it is needed to reduce individual radiaton exposure limit further. In this paper, an optimization techique was suggested for selection of alternatives for reducing occupational radiation exposure, and used in reviewing alternatives given by a plant utility. After the basic analysis, sensitivity analysis was performed to consider the variabilities of the economic variables. From the result, it was found that an option using steam generator nozzle dam and torquing machine was the best with respect to total benefits, and in case of multi-attribute utility analysis, an option using Co-No seal had the highest utility. Therefore, it was necessary to apply more than one technique togeter in optimization study and to consider qualitative factor, too.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.301-306
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• 2016

Objectives: Direct-reading instrument(Photoionization detectors, PID) and quantitative analysis using active type air sampling (Gas chromatography-flame ionization detector, GC-FID) were tested to evaluate their ability to detect volatile organic compounds(VOCs) in a semiconductor manufacturing plant. Methods: The organic compounds used were acetone and ethanol which are normally used as cleaning solutions in the semiconductor manufacturing. The evaluation was based on the preparation of test solutions of known acetone and ethanol concentration in a chamber($600{\times}600{\times}1150mm$). Samples were prepared that would be equivalent to 5~100 ppm for acetone and 10~ 200 ppm ethanol. GC-FID and PID were evaluated simultaneously. Quantitative analysis was performed after sampling and the direct-reading instrument was checked using real-time data logging. Results: Positive correlations between PID and GC-FID were found for acetone and ethanol at 0.04~2.4% for acetone(TLV: 500 ppm) and 0.1~8.3% for ethanol(TLV: 1000 ppm). When the sampling time was 15 min, concentration of test solution was the most similar between measurement methods. However, the longer the sampling time, the less similar the results. PID and GC-FID had similar exposure patterns. Conclusions: The results indicate that PID and GC-FID have similar exposure pattern and positive correlation for detection of acetone and ethanol. Therefore, PID can be used for exposure monitoring for VOCs in the semiconductor manufacturing industry. This study has significance in that it validates measuring occupational exposure using a portable device.

• Journal of Preventive Medicine and Public Health
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• v.38 no.4
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• pp.465-472
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• 2005

Objectives : The aim of this study was to assess the effect of air pollution on the daily respiratory symptoms of elementary school children in Seoul. Methods : Using the panel study design, we collected diary data for the children's respiratory symptoms during the 1st day$\sim$15th day of April, July, October and December in 2003 among the 2nd and 3rd grade elementary school students. We merged the respiratory symptom data with the ambient air pollution data that was monitored by Ministry of Environment. Using a generalized estimate equation, we evaluated the relationship between the daily symptoms of the subjects and the exposure to ai r pollution after controlling for various potential confounders. Results : The nitrogen dioxide (NO2) exposure of the current day significantly increased the upper respiratory symptoms (adjusted odds ratio=1.12, 95% CI=1.01-1.24) and the lower respiratory symptoms (adjusted odds ratio=1.18, 95% CI=1.06-1.31) in the elementary school children. The sulfur dioxide (SO2) and carbon monoxide (CO) exposure in the current day was associated with the lower respiratory symptoms (adjusted odds ratio=1.12, 95% CI=1.01-1.25 for SO2; adjusted odds ratio=1.16, 95% CI=1.02-1.32 for CO). Conclusions : We found that exposure to air pollution affects the daily respiratory symptoms in children. This study suggests that the effect on children's health? due to the short term changes in air pollution levels needs to be considered as an important public health problem.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.642-657
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• 2022

The fourth industrial revolution became a decisive opportunity to increase our dependence on non-face-to-face services. Therefore, this study tried to derive a new strategic plan for non-face-to-face marketing by discussing the short-form branded content currently in the spotlight among the digital native generation. In particular, focusing on the phenomenon of co-viewing, where short-form branded content is viewed and communicated on social media, how exposure type of branded content affect attitudes toward short-form branded content and the products it contains verified. In addition, this research presents the perceived sense of belonging as a mediating variable. It was confirmed through an experiment whether the sense of belonging perceived by consumers during the co-viewing process significantly mediated the relationship between the exposure types and consumer attitudes. As a result of the study, it was found that the exposure type significantly affected the attitude towards the contents and the products contained in them. Furthermore, the perceived sense of belonging was also significant as a mediating variable.

• The Korean Journal of Zoology
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• v.14 no.3
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• pp.119-124
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• 1971

Male mice of strain SM were given 128 rads of single whole-body gamma-irradiation of $^{60}Co$, 14 to 16 minutes following a subcutaneous injection of physiological saline or cortisone acetate (1mg/day, for 4 days preirradiation). The serum protein patterns and the level of the total serum proteins were determined at various time intervals after exposure. Total serum protein was determined by Biuret method and serum protein fractions and A/G ratio were determined by paper electrophoresis using Whatman No.1 filter paper and barbital buffer (pH 8.6, ionic strength 0.06). 1. Total body gamma-irradiation caused a rise in the level of the total serum protein at 1 day and in the level of the serum albumin-globulin ratio at 5 days in both cortisone acetate-treated and control groups. 2. Cortisone acetate delayed the total serum protein rise at 5, 10, and 20 days after exposure. 3. Cortisone acetate delayed the A/G ratio rise at 1, 5, and 10 days after exposure. 4. It may be inferred that cortisone greatly reduces the sensitivity of mice to gamma-irradiation on the blood protein, probided that cortisone is given before the exposure.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.1-3
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• 2000

Indoor carbon monoxide (CO) concentration and personal CO exposures were measured Asan where CO poisoning from twenty coal usage briquette as a domestic fuel to cook and space heating. Twenty-five were houses selected from the Asan area for the survey conducted in February 1997. Newly developed passive CO samplers were placed in the kitchen and living room for the indoor concentration measurement and were worn by homemakers for personal exposure monitoring. The daily average of indoor CO concentration was 16ppm in the kitchen and 10ppm in the living room. The indoor concentration and personal exposures to CO were different in types of the space heating system. House ventilating methods and socioeconomic conditions were also important factors in determining the indoor and personal CO level in Asan.

• The Korean Journal of Malacology
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• v.32 no.1
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• pp.45-54
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• 2016

To evaluate the applicability of cellular energy allocation (CEA) in the bivalves as a biomarker for the assessment of environmental contamination, the energy contents and energy consumption in several tissues of the Manila clam, Ruditapes philippinarum were analyzed. The contents of lipid, glucose, protein and electron transport system (ETS) activity in the foot, siphons, gills, and body of R. philippinarum exposed to crude oil-spiked sediments were measured at 1, 2, 4, 7, 10 days after exposure. The reserved energy (energy available, EA) in the lipid, glucose and protein decreased as contamination level and exposure time increased. In contrast, the ETS activity (energy consumed, EC) showed the reverse tendency. The order of available energy contents were foot > siphons > gill > body. Significant differences in both EA and EC were found only at the highest contamination level (58.3 mg TPAHs/kg DW). EA decreased significantly in the foot and gill at 1 day, in the body at 2 and 7 days after exposure. EC increased significantly in the body at 4 days after exposure. CEA showed higher sensitivity to the contamination than EA or EC. Especially, CEA in the foot and body decreased significantly at lower ranges of contamination level (as low as 6.5 mg TPAHs/kg DW) during 1 to 7 days after exposure. The CEA is more useful than EA or EC alone for the assessment of sediment contamination at lower level that acute toxicity could not be detected. CEA analyses in the body of R. philippinarum after 4 days' exposure to contaminated sediments seem to be the most sensitive and reliable.