• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.128-135
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• 2010

The main purpose of this study was to develop the greenhouse gas emission factor for power plant using sub-bituminous coal. In Korea, Fired power plant are a major source of greenhouse gases within the fossil fuel combustion sectors, thus the development of emission factors is necessary to understand the characteristics of the national specific greenhouse gas emission and to develop nation specific emission factors. These emission factors were derived from the $CO_2$ concentrations measurement from stack and fuel analysis of sub-bituminous coal. Caloric value of sub-bituminous coal used in the power plants were 5,264 (as received basis), 5,936 (air-dried basis) and 6,575 kcal/kg (dry basis). The C emission factors by fuel analysis and $CO_2$ concentration measurement was estimated to be 26.7(${\pm}0.9$), 26.3(${\pm}2.8$)tC/MJ, respectively. Our estimates of C emission factors were comparable with IPCC default value.

• Journal of agricultural medicine and community health
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• v.25 no.1
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• pp.99-112
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• 2000

This survey was conducted to assess the utilization of health center including health sub-center and community health post and the health service demand of residents in a urban and rural unified community. Officials in Up·Myun·Dong offices visited randomly sampled 4,027 households(4.6% of total households in unified City) which included 3,337 households in urban area(4.9% of total households) and 690 households in rural area(3.7% of total households) and interviewed with heads or housewives of the households in September, 1995. There were significant differences in health-related demographic characteristics including age-sex distribution, educational level, period of residence in the community and medical insurance status of the interviewees between urban and rural areas. Of the respondents, 64.8% in urban area and 55.6% in rural replied that they had utilized the health center in the past. The most common purpose for visiting the health center was to get vaccination in urban area and to get outpatient care in rural area. The top priority health center activity that needs to be reinforced was communicable disease control and over 90% of the respondents preferred to have mobile clinic and home health care service in were also highly demanded. Eighty-six percent of the urban respondents replied that a health sub-center must be established in urban area. In the rural area, 90.3% of the respondents replied that they wanted to maintain the health sub-center and 88.3% wanted to maintain the community health post. Along with the improvement of facilities and equipments of the health center by Rural Health Service Improvement Project, new health service programs must be developed to meet the demand of the community.

• Journal of Environmental Health Sciences
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• v.39 no.2
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• pp.144-150
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• 2013

Objectives: Cooking activity in indoor environments can generate particulate matter. The objective of this study was to determine the concentrations of ultrafine particles (UFP), $PM_{2.5}$, and $PM_{10}$ in cooking and non-cooking areas of major department stores in Seoul. Methods: Eighteen department stores in Seoul, Korea were measured for concentrations of particulate matter. Using real-time monitors, concentrations of UFP, $PM_{2.5}$ and $PM_{10}$ were simultaneously measured in cooking and non-cooking areas on the floor with a food court and a non-cooking floor. Results: The concentrations of UFP, $PM_{2.5}$ and $PM_{10}$ were significantly higher in cooking areas than in noncooking areas and non-cooking floors (p<0.05). UFP and $PM_{2.5}$ were significantly correlated in cooking areas and non-cooking areas but not in non-cooking floors. $PM_{2.5}$ were consisted of approximately 81% in $PM_{10}$ and highly correlated with $PM_{10}$ in all places. Conclusion: A higher correlation between UFP and $PM_{2.5}$ was shown on cooking floor than on non-cooking floor in department stores. High levels of fine particles were caused by cooking activities at food courts. The further management of PM is needed to improve the indoor PM levels at food courts in department stores.

• Safety and Health at Work
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• v.14 no.4
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• pp.358-367
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• 2023

Background: This study aimed to develop and assess the psychometric features of the Physical Activity at Workplace Questionnaire (PAWPQ) based on the Social Cognitive Theory (SCT) to evaluate employees' physical activity (PA) behaviors at the workplace. Methods: This psychometric cross-sectional study was conducted on 455 employees working in one of the gas refineries in Iran. The participants were selected using the proportional stratified sampling method in 2019. The data collection tools were a demographic information questionnaire, the short form of the International Physical Activity Questionnaire (IPAQ), and a questionnaire developed based on the SCT, whose psychometric features were confirmed in terms of validity and reliability. Data were analyzed using SPSS₂₂ and AMOS₂₀ software. Results: The first version of PAWPQ-SCT had 74 items. After evaluating content and face validity, nine items were removed. The results of the content validity index (0.98), content validity ratio (0.86), and impact score (3.62) were acceptable for the whole instrument. In exploratory factor analysis, after removing seven items-58-item final version of the scale-six factors could explain 73.54% of the total variance. The results of structural equation modeling showed the acceptable fit of the model into the data (RMSEA = 0.052, CFI = 0.917, NFI = 0.878, TLI = 0.905, IFI = 0.917, CMIN/DF = 2.818). Cronbach's alpha coefficient and Intraclass Correlation were 0.90 and 0.86, respectively. Conclusion: This study confirmed that the psychometric features of the 58-item final version of PAWPQSCT constructs were acceptable in a sample of Iranian employees. This questionnaire can be used as a valid and reliable tool to evaluate Iranian employees' PA behaviors and develop effective educational interventions for workers and managers.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.4
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• pp.389-397
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• 2018

The starfish, Asterina pectinifera Muller and Troschel (Asterinidae) is an indigenous species commonly found in all coasts of Korea causes damages to shellfish farms. In order to exterminate A. pectinifera, they are dried and used as fertilizer. Although various studies have been conducted to create high added value from the retrieved A. pectinifera, their actual utilization is relatively low. Accordingly, this study aimed to find new practical uses of starfish by identifying useful ingredients for skin anti-aging. Two polyhydroxysteroids and one asterosaponin were isolated from the A. pectinifera. The structures of these compounds were identified as $5{\alpha}$-cholestane-$3{\beta},6{\alpha},7{\alpha},8,15{\alpha},16{\beta},26$-heptol, $5{\alpha}$-cholestane-$3{\beta},4{\beta},6{\alpha},7{\alpha},8,15{\beta},16{\beta},2$6-octol, and asterosaponin $P_1$ on the basis of chemical and spectroscopic analysis. Among these compounds, we have found that asterosaponin $P_1$ increased epidermal stem cell proliferation and the expression of hyaluronan synthase-2 and hyaluronan synthase-3 gene, which are enzymes that synthesize water-binding matrix hyaluronic acids in keratinocytes. In addition, asterosaponin $P_1$ increased synthesis of pro-collagen type I, a major dermal collagen in fibroblasts. As a result, asterosaponin $P_1$ isolated from A. pectinifera could be used as a useful cosmetic ingredient that improves skin symptoms accompanying skin aging.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.414-424
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• 2022

Objectives: This study was established to ascertain the requirements and implementation of core competencies for employees of the a workers' health center. Methods: The study consisted of a four-step process: a literature review, focus group interviews, expert opinions, and a questionnaire. The survey was conducted online among 119 employees of the National Workers' Health Center. Results: As a result of the research, eleven core competencies and 37 sub-competencies were derived in three areas: Competence as a social worker, competence to perform duties, and competence for maintaining expertise. The key demands for core competencies were "health consultation" and "understanding of small businesses.". They responded that they needed to "maintain an ethical attitude" and "consult on workers' health.". The largest score difference between core competency requirements and competency implementation was "collaboration with the community.". Conclusions: It is necessary to increase competencies not only for competencies with high core requirements, but also for relatively low competencies. In addition, efforts should be made to improve the core competencies of the employees of the Workers' Health Center to effectively respond to changes in the industrial structure and crises such as COVID-19.

• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.519-522
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• 2021

The Chinese edible frogs, Hoplobatrachus rugulosus (n=20), and the striped snakehead fish, Channa striata (n=34), were purchased from local markets in 3 administrative regions of Cambodia (Phnom Penh, Pursat, and Takeo Provinces) from May 2017 to April 2019, and their infection status with Gnathostoma sp. larvae was investigated. The frogs and fish were transported to the laboratory with ice and examined using the artificial digestion method. Advanced 3rd-stage larvae (AdL₃) of Gnathostoma spinigerum, 24 in total number (1-6 larvae/frog), were detected from 6 (60.0%) out of 10 frogs purchased from Phnom Penh. No gnathostome larvae were detected in 10 frogs purchased from Takeo Province and 34 snakeheads from Phnom Penh, Pursat, and Takeo Provinces. AdL₃ isolated from the frogs were 2.55-3.90 mm long and 0.31-0.36 mm wide. They had a characteristic head bulb (0.081×0.191 mm in average size) with 4 rows of hooklets, a muscular long esophagus (0.950-1.230 mm long), and 2 pairs of cervical sacs (0.530-0.890 mm long). The average number of hooklets in the 1st, 2nd, 3rd, and 4th rows was 41, 45, 48, and 51, respectively. These features were consistent with G. spinigerum AdL₃. By the present study, it has been first confirmed that the Chinese edible frog, H. rugulosus, from Phnom Penh serves as a second intermediate host for G. spinigerum, although their intensity of infection was not so high compared to other previously reported localities.

• Journal of Environmental Health Sciences
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• v.46 no.4
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• pp.444-456
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• 2020

Objectives: This study developed an index for the indoor air quality management of city buses to allow the provision of indoor air quality information to city bus users. Methods: Nine city buses in Seoul were measured for PM₁₀, PM_2.5, CO₂, temperature, and relative humidity through IoT sensors. Big data collected through the sensors was analyzed to identify indoor air quality on city buses and graded through the index. Results: As a result of dividing the measured city bus data into five grades through the IAQ index, PM₁₀ was rated "good" for 30.4% of the total measured values, and 9.2% were rated "risky". For PM_2.5, 67.7 percent were rated "good" and 0.4 percent were rated "risky". For CO₂, 0.9% were 'good' and 1.1% were 'risky'. The results of the classification through the IAQ index for city buses showed that the impact of good, normal, sensitive, bad, and dangerous were 2.7, 38.8, 46.0, 12.4, and 0.1%, respectively. According to the analysis by measurement area, Seocho-gu, Gangnam-gu, Seongdong-gu, Gwangjin-gu, and Dobong-gu are "normal" and other areas (Seodaemoon-gu, Jongno-gu, Yongsan-gu, Jung-gu, Seongbuk-gu, Dongdaemun-gu, Junggye-gu, Gangbuk-gu, and Nowon-gu) are all rated "sensitive". Conclusions: When analyzing cases where PM₁₀ and CO₂ indices are in the "bad" zone, the concentration is generally found to increase during rush hour, during which there are a large number of passengers. It is expected that indoor air quality management in vehicles will be necessary during rush hour.

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.329-340
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• 2024

Mangiferin is a kind of natural xanthone glycosides and is known to have various pharmacological activities. However, since the beneficial efficacy of this compound has not been reported in retinal pigment epithelial (RPE) cells, this study aimed to evaluate whether mangiferin could protect human RPE ARPE-19 cells from oxidative injury mimicked by hydrogen peroxide (H₂O₂). The results showed that mangiferin attenuated H₂O₂-induced cell viability reduction and DNA damage, while inhibiting reactive oxygen species (ROS) production and preserving diminished glutathione (GSH). Mangiferin also antagonized H₂O₂-induced inhibition of the expression and activity of antioxidant enzymes such as manganese superoxide dismutase and GSH peroxidase, which was associated with inhibition of mitochondrial ROS production. In addition, mangiferin protected ARPE-19 cells from H₂O₂-induced apoptosis by increasing the Bcl-2/Bax ratio, decreasing caspase-3 activation, and blocking poly(ADP-ribose) polymerase cleavage. Moreover, mangiferin suppressed the release of cytochrome c into the cytosol, which was achieved by interfering with mitochondrial membrane disruption. Furthermore, mangiferin increased the expression and activity of heme oxygenase-1 (HO-1) and nuclear factor-erythroid-2 related factor 2 (Nrf2). However, the inhibition of ROS production, cytoprotective and anti-apoptotic effects of mangiferin were significantly attenuated by the HO-1 inhibitor, indicating that mangiferin promoted Nrf2-mediated HO-1 activity to prevent ARPE-19 cells from oxidative injury. The results of this study suggest that mangiferin, as an Nrf2 activator, has potent ROS scavenging activity and may have the potential to protect oxidative stress-mediated ocular diseases.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1190-1197
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• 2016

The acid response of Bifidobacterium longum subsp. longum BBMN68 has been studied in our previous study. The fab gene, which is supposed to be involved in membrane fatty acid biosynthesis, was demonstrated to be induced in acid response. In order to investigate the relationship between acid response and cell membrane fatty acid composition, the acid adaptation of BBMN68 was assessed and the membrane fatty acid composition at different adaptation conditions was identified. Indeed, the fatty acid composition was influenced by acid adaptation. Our results showed that the effective acid adaptations were accompanied with decrease in the unsaturated to saturated fatty acids ratio (UFA/SFA) and increase in cyclopropane fatty acid (CFA) content, which corresponded to previous studies. Moreover, both effective and non-effective acid adaptation conditions resulted in decrease in the C_18:1 cis-9/C_18:1 trans-9 ratio, indicating that the C_18:1 cis-9/C_18:1 trans-9 ratio is associated with acid tolerance response but not with acid adaptation response. Taken together, this study indicated that the UFA/SFA and CFA content of BBMN68 were involved in acid adaptation and the C_18:1 cis-9/C_18:1 trans-9 ratio was involved in acid tolerance response.