• Applied Microscopy
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• v.24 no.1
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• pp.77-85
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• 1994

In order to investigating the pulmonary toxicity of the O-chlorobenzyledene malononitrile (CS), lacrimating agent, $2.6g/m^3$ of CS was inhalated to Sprague-Dawley rats in the plastic chamber for 20 minutes. The ultrastructural changes of type II pneumocytes in the lung were observed with Hitachi 600 transmission electron microscope. The results obtained were as follows: 1. 3 hours after exposure to CS the fusion of surface microvilli, dilatation of cristernae of the rough endoplasmic reticulum, atrophy of Golgi complex and condensation, deletion of lamellated membranes in lamellar bodies were observed in type II pneumocytes. 2. One and 2 days after CS-exposure, disorganization of mitochondrial double membranes, fragmentations of rough endoplasmic reticulum were found in the great alveolar cells. In addition, decrease in amount of polyribosome granules and deletion or condensation of lamellated membranes in lamellar bodies were also observed. 3. 4 days after exposure to CS, the type II pneumocyte revealed new whorled lamellar membranes in lamellar bodies, a few intact rough endoplasmic reticulum and restoration of polyribosome granules. It is consequently suggested that CS induces degenerative changes of cytoplasmic organelles in the type II pneumocytes.

• Journal of Korea Multimedia Society
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• v.21 no.7
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• pp.764-771
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• 2018

In this paper, we propose a high-quality image acquisition algorithm using only a single image, which the high-quality image is normally referred as HDR ones. In order to acquire the HDR image, conventional methods need many images having different exposure values at the same scene and should delicately adjust the color values for a bit-expansion or an exposure fusion. Thus, they require considerable calculations and complex structures. Therefore, the proposed algorithm suggests a completely new approach using one image for the high-quality image acquisition by applying statistical difference and histogram manipulation, or histogram specification, techniques. The techniques could control the pixel's statistical distribution of the input image into the desired one through the local and the global modifications, respectively. As the result, the quality of the proposed algorithm is better than those of conventional methods implemented in commercial image editing softwares.

• Journal of the Korean Society of School Health
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• v.32 no.2
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• pp.77-87
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• 2019

Purpose: This study was conducted to examine the prevalence of current smoking and the factors that influence current smoking among male high school students in Korea according to school type. Methods: Data were extracted from the Korea Youth Risk Behavior Web-Based Survey (2017) and multiple logistic regression was used based on complex sample analysis. The study sample comprised of 15,777 male high school students: 12,583 from general high schools (GHS) and 3,194 from specialized vocational high schools (SVHS). Results: The prevalence of current smoking was significantly higher in SVHS students (19.6%) compared to GHS students (12.6%). Low academic achievement, depressive symptoms, current drinking, and high household economic status were commonly associated with current smoking in male students from both school types. However, exposure to secondhand smoking at home, non-exposure to anti-smoking advertisement, exposure to tobacco advertisement, participation in smoking prevention or cessation education were related to current smoking in GHS students, while living in rural area was associated with current smoking in SVHS students. Conclusion: To reduce current smoking among male high school students, it is necessary to develop smoking prevention policies reflecting the factors associated with current smoking that are different by school type.

• BioChip Journal
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• v.12 no.4
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• pp.304-308
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• 2018

Atopic disease is caused by a complex combination of environmental factors and genetic factors, and studies on influence of exposure to various environmental factors on atopic diseases are continuously reported. However, the exact cause of atopic dermatitis is not yet known. Our study was conducted to analyse the association of SNPs with the development of atopic disease in a small cohort. Samples were collected from the Mothers' and Children's Environmental Health (MOCEH) study and 192 cord blood DNA samples were used to identify incidence of atopy due to influence of exposure to environmental factors. Genetic elements were analysed using a precision medicine research (PMR) array designed with various SNPs for personalized medicine. Case-control analysis of atopy disease revealed 253 significant variants (p<0.0001) and SNPs on five genes (CARD11, ZNF365, KIF3A, DMRTA1, and SFMBT1) were variants identified in previous atopic studies. These results are important to confirm the genetic mutation that may lead to the onset of foetal atopy due to maternal exposure to harmful environmental factors. Our results also suggest that a small-scale genome-wide association analysis is beneficial to confirm specific variants as direct factors in the development of atopy.

• Journal of the Korea Safety Management & Science
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• v.26 no.2
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• pp.87-92
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• 2024

This study aims to compare six observational methods for assessing arm- and hand-intensive tasks, based on literature review. The comparison was conducted in viewpoints of body regions, force/external load, motion repetition, other factors including static posture, coupling, duration/break, pace, temperature, precision task, and final risk or exposure level. The number of risk factors assessed was more, and assessment procedure was more complex than the observational methods for assessing whole-body postural loads such as Ovako Working Posture Analysis System(OWAS), Rapid Upper Limb Assessment(RULA), and Rapid Entire Body Assessment(REBA). Due to these, the intra- and inter-reliabilities were not high. A past study showed that while Hand Arm Risk Assessment Method(HARM) identified the smallest proportion of the work tasks as high risk, Strain Index(SI) and Quick Exposure Check(QEC) hand/wrist were the most rigorous with classifying most work tasks as high risk. This study showed that depending on the observational technique compared, the evaluation factors, risk or exposure level, and evaluation results were different, making it necessary to select a technique appropriate for the characteristics of the work being assessed.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.6
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• pp.575-582
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• 2016

Seoul city has high population density as well as high traffic congestion, which are vulnerable to exposure of environmental pollutions caused by car traffic. However, recent studies are only on local regions about road traffic and air pollution or health effect of road traffic on residents. Thus, comprehensive study data are needed in terms of overall Seoul regions. In this study utilized the nitrogen dioxide concentration through the national air pollution monitoring network data, 2012 to 2013. It also divided regions into high and low exposure districts via the Origin destination data developed by the Korea transport institute to quantify and evaluate the effect of transport policies and analyzed a correlation of asthma symptoms with high and low exposure districts through raw data of community health survey from the Korea centers for disease control and prevention. Based on the collected data, the pearson's correlation analysis was conducted between air pollution substance concentration and high exposure district and multiple logistic regression analysis was conducted to determine the effect of traffic environment and factors on asthma symptoms of residents. Accordingly, the following results were derived. First, the high exposure district was higher concentrations of nitrogen dioxide ($NO_2$) as per time compared to those of the low exposure district (p<0.01). Second, analysis on correlation between average daily environmental concentration in the air pollution monitoring network and road traffic showed that nitrogen dioxide had a significant positive correlation (p<0.01) with car traffic and total traffic as well as with truck traffic (p<0.05) statistically. Third, an adjusted odds ratio about asthma doctor's diagnosis in the high and low exposure districts was analyzed through the logistic regression analysis. With regard to an adjusted model 2 (adjusted gender, age, health behavior characteristics, and demographic characteristics) odds ratio of asthma doctor's diagnosis in the high exposure district was 1.624 (95% CI: 1.269~2.077) compared to that of the low exposure district, which was significant statistically (p<0.001).

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.257-267
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• 2004

Our study investigated the association between solvent exposure and acquired color vision loss using the Lanthony D-15 desaturated panel in petrochemical industry. Since neurotoxic effects associated with chronic solvent exposure, subjects with more than 6 months of exposure were included. Exposure assesment was estimated mean, maximum and cumulative 8hr TWA from individual 8-hour sampling. Exposure status were classified into two groups, occupationally exposed group to solvent and a non-exposed group. The results showed that CCI was positively related for age. According to the results of qualitative analysis, there was no significant difference in the prevalence of specific Type of dyschromatopsia the two examined group. However, the prevalence showed a higher proportion of dyschromatopsia to solvent exposure. It was affect with acquired dyschromatopsia(Type II, III and Complex) in exposed worker group(5.9%,7.86%,14.99%, respectively) than in the nonexposed group(6.16%,7.55%,13.71%, respectively). After each variable was adjusted for age, alcohol and tobacco consumption, a relationship between acquired dyschromatopsia and exposure showed an increase in the Odds ratio as compared to the nonexposed group at only left. The results showed that acquired dyschromatopsia was positively related to age (p<0.001). The results showed that solvent exposure, although not significant, could cause the acquired dyschromatopsia and visual system can serve important information on early neurotoxic effects in generally. Therefore, we need to concerns about eye health in workers.

• Environmental Analysis Health and Toxicology
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• v.12 no.3_4
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• pp.31-41
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• 1997

Public concerns about hazardous health effect from the exposure to organic by-products of the chlorination have been increased. There are numerous studies reporting that chlorination of drinking water produces numerous chlorinated organic by-products including THMs, HAAs, HANs. Some of these products are known to be animal carcinogens. The purpose of this study was to estimate health risk of DBPs by chlorinated drinking water ingestion in Seoul based on methodologies that have been developed for conducting risk assessment of complex-chemical-mixture. The drinking water sample was collected seperately at six water treatment plant in Seoul at March, April, 1996. In tap water of households in Seoul, DBPs were measured wilfh the mean value of 36.6 $\mu$g/L. Risk assessment processes,. which include processes for the estimation of human cancer potency using animal bioassay data and calculation of human exposure, entail uncertainties. In the exposure assessment process, exposure scenarios with various assumptions could affect the exposure amount and excess cancer risk. The reference dose of haloacetonitriles was estimated to be 0.0023 mg/kg/day by applying dibromoacetonitrile NOAEL and uncertainty factor to the mean concentration. In the first case, human excess cancer risk was estimated by the US EPA method used to set the MCL (maximum contaminant level). In the second and third case, the risk was estimated for multi-route exposure with and without adopting Monte-Carlo simulation, respectively. In the second case, exposure input parameters and cancer potencies used probability distributions, and in the third case, those values used point estimates (mean, and maximum or 95% upper-bound value). As a result, while the excess cancer risk estimated by US EPA method considering only direct ingestion tended to be underestimated, the risk which was estimated by considering multi-route exposure without Monte-Carlo simulation and then using the maximum or 95% upper-bound value as input parameters tended to be overestimated. In risk assessment for Trihalomethanes, considering multi-route exposure with adopting Monte-Carlo analysis seems to provide the most reasonable estimations.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.1
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• pp.56-66
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• 1996

In this study, the characteristics of generation and propagarion of transient wave induced in the assembly of four collecting plate upon the propagation of waves are analyzed. Also double exposure holographic inteferometry using ruby pulse laser is built in order to investigate the propagation of transient waves generated by impact load. When impact load was applied at edge of connecting band, the vibration of collecting plates was generated from the contact points between collecting plate and band which connects four collecting plates. Waves generated from the lower part and those reflected from the upper part were mixed as time went on and then formed very complex shapes. Also, when impact load was aplied at center of collecting plate, the waves propagating across the convexo-concave plane were reflected partly at curved section. Therefore the vibration amplitude was decreased as the transiet waves were propagated through the convexo-concave plane.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.649-654
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• 2009

The immune system is comprised of cells and molecules whose collective and coordinated response to the introduction of foreign substance is referred to as the immune response. Defense against microbes is mediated by the early reaction (innate immunity) and the late response (adaptive immunity). Innate immunity consists of the epithelial barrier, phagocytes, complement and natural killer cells. Adaptive immunity, a more complex defense reaction, consists of activation of later-developed lymphocytes that, when stimulated by exposure to infectious agents, increase in magnitude and defensive capabilities with each successive exposure. In this review we discuss recent advances in important primary immune deficiency disorders of innate immunity (chronic granulomatous disease, leukocyte adhesion deficiency) and adaptive immunity (severe combined immune deficiency, Wiskott- Aldrich syndrome).