• 대한영양사협회학술지
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• 제26권3호
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• pp.183-195
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• 2020

Endocrine-disrupting chemicals (EDCs) are chemicals present in the environment that interfere with the normal hormone functions of various organisms and cause genetopathy, deformities, or cancer. This study surveyed the awareness of EDCs with 242 cooking staff at 242 meal service facilities for children located in a part of Gyeonggi Province. To minimize infants' exposure to EDCs, the subjects were provided with information on EDCs for two months. The behavior of reducing exposure to EDCs was analyzed according to the awareness of EDCs and work ethics. In addition, the effects before and after being provided with the information were evaluated. According to the results, the levels of awareness of EDCs and work ethics' scores of the cooking staff were high with 3.95 and 4.39 points, respectively, out of five points. In addition, a higher awareness of EDCs and a higher work ethics' score were associated with an improved behavior of reducing exposure to EDCs (P<0.05). The overall cooking and cleaning behavior for reducing exposure to EDCs showed improvement after providing information (P<0.01). Therefore, these results suggest that it is important to provide continuous education to enhance the awareness of EDCs, work ethics, and behavior to reduce exposure to EDCs.

• 한국직업건강간호학회지
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• 제28권4호
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• pp.285-292
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• 2019

Purpose: This study aimed to examine the factors associated with behavior that reduces exposure to environmental hormones among nursing students. Methods: Data were collected from 160 nursing students in D and B cities, using self-report questionnaires. Data were analyzed using SPSS 22.0, and the analyses included descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient test, and stepwise multiple regression. Results: Behavior that reduces exposure to environmental hormones differed significantly in terms of the participants' knowledge about environmental hormones. Behavior that reduces exposure to environmental hormones was negatively correlated with knowledge of environmental hormones, attitude towards pro-environmental behavior, and environmental self-efficacy; these factors were significant predictors of behavior that reduces exposure to environmental hormones, and accounted for 27.0% of the variance. Conclusion: Environmental self-efficacy was identified as the most significant factor affecting behavior that reduces exposure to environmental hormones in nursing students. Therefore, it is necessary to develop programs to improve pro-environmental behavior and environmental self-efficacy in nursing students.

• Computers and Concrete
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• 제26권2호
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• pp.115-125
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• 2020

To reduce the damage of concrete in fire, a new type of lightweight cinder aggregate concrete was developed due to the excellent fire resistance of cinder. To further enhance its fire resistance, Polypropylene (PP) Fibers which can enhance the fire resistance of concrete were also used in this type of concrete. However, the bond behavior of this new type of concrete after fire exposure is still unknown. To investigate its bond behavior, 185 specimens were heated up to 22, 200, 400, 600 or 800℃ for 2 h duration respectively, which is followed by subsequent compressive and tensile tests at room temperature. The concrete-rebar bond strength of C30 PP fiber-reinforced cinder concrete was subsequently investigated through pull-out tests after fire exposure. The microstructures of the PP fiber-reinforced cinder concrete and the status of the PP fibre at different temperature were inspected using an advanced scanning electron microscopy, aiming to understand the mechanism of the bonding deterioration under high temperature. The effects of rebar diameter and bond length on the bond strength of PP fiber-reinforced cinder concrete were investigated based on the test results. The bond-slip relation of PP fiber-reinforced cinder concrete after exposure at different temperature was derived based on the test results.

• 여성건강간호학회지
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• 제25권4호
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• pp.423-433
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• 2019

Purpose: The study aimed to examine the effects of sleep pattern, stress, and attitude towards menstruation, and behavior that causes a reduction in exposure to endocrine disrupting chemicals (EDCs) in the course of premenstrual syndrome (PMS) in female adolescents. Method: In total, 200 girls attending middle school in K city were recruited via convenience sampling between December 11 and 31, 2018, and 192 subjects were selected for the analysis. Data were analyzed using descriptive statistics, an independent t-test, ANOVA, Pearson's correlation coefficient, and multiple regression. Results: Overall, 9 (4.7%), 152 (79.2%), and 31 (16.1%) students had morning-, intermediate-, and evening-type sleep pattern, respectively. The mean scores for school-related stress were highest. Scores for stress regarding relationships with friends were the lowest. The mean score for attitudes toward menstruation was 72.33 out of 147. The mean score for behavior that led to a reduction in EDCs exposure was 56.57 out of 85. The mean scores for PMS severity were 25.30 and 38.39 out of 60. Analysis of factors affecting PMS revealed that severity of menstrual pain (β=.28), use of analgesics during menstruation (β=.17), family history of PMS (β=-.16), stress (β=.19), and behavior that reduces EDCs exposure (β=-.17) exerted significant effects on PMS. The explanatory power of these variables was 37%. Conclusion: The findings propose the necessity of a health intervention program including educational information, which can reduce PMS in adolescents, induce the behaviors which can decrease exposure to EDCs, and activities for managing the stress levels.

• 한국학교보건학회지
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• 제32권2호
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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.

• 한국산학기술학회논문지
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• 제19권6호
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• pp.432-439
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• 2018

본 연구는 치과위생사를 대상으로 방사선 관리에 대한 지식, 태도, 안전관리 행위, 방사선 피폭 불안감을 분석하고 이에 영향을 미치는 요인들을 분석함으로써 방사선 안전 관리 수준을 향상하고 방사선 취급에 대한 올바른 인식 전환과 불안감을 줄이는 방안을 도출하고자 연구하였다. 연구기간은 2017년 9월 10일부터 10월 31일까지 전라북도에 근무하는 치과위생사 280명을 대상으로 SPSS 12.0 프로그램을 사용하여 빈도, 기술통계, 다중회귀분석을 실시하여 분석하여 다음과 같은 결과를 얻었다. 방사선 질 관리에 대한 지식 정도의 평균은 8.07 였고, 정답률은 75.3% 였다. 태도 정도는 96.1%가 긍정적인 태도를 보였으며, 방사선 안전관리 행위는 촬영자는 4.11 였고, '방사선 촬영 시 항상 TLD(개인선량계)를 착용한다'는 4.58 로 가장 높았다. 환자 방사선 안전관리 행위는 3.86 였고, '방사선촬영 전 가임기 여성의 임신 여부를 확인한다'는 4.69 로 가장 높았다. 방사선 피복 뷸안감은 3.86 였고, '임신 중 일 때 태아의 건강 문제로 염려된다'는 4.13로 가장 높았다. 방사선 피폭 불안감에 영향을 미치는 요인으로는 방사선 안전관리 행위가 낮을수록, 연령이 낮을수록, 방사선 촬영경력이 낮을수록, 최종학력이 높을수록, 월 소득이 많을수록, 직위가 높을수록 유의한 영향을 미치는 것으로 나타났다(p<0.05). 이상의 연구결과를 토대로 치과위생사는 방사선 질 관리에 대한 지식, 태도, 안전관리 행위는 높았으나, 방사선 피폭 불안감은 높은 불안감을 가지고 있어 방사선 안전 관리 수준을 향상시켜 방사선 피폭 불안감을 줄일 수 있는 방안 마련이 이루어져야 할 것으로 사료된다.

• Corrosion Science and Technology
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• 제21권4호
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• pp.258-272
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• 2022

Steel structures exposed to the outdoors experienced several types of corrosion, which may reduce their thickness. Since atmospheric corrosion can induce economic losses, it is important to consider the atmospheric corrosion behavior of a variety of metals and alloys. This work performed outdoor exposure tests for 10 years at 14 areas in Korea and calculated the atmospheric corrosion rate of weathering steel. This paper discussed the atmospheric corrosion behavior of weathering steel based on various corrosion factors. The average corrosion rates in coastal, industrial, urban, and rural areas were found to range from (2.83 to 4.23) ㎛/y, (2.99 to 4.23) ㎛/y, (1.72 to 3.14) ㎛/y, and (1.57 to 2.85) ㎛/y respectively. It should be noted that the maximum corrosion rate was about 6.0 times greater than the average corrosion rate. Regardless of the exposure sites, the color differences were increased, but the glossiness was reduced and there was no relationship between the corrosion rate and environmental factors and the glossiness.

• Safety and Health at Work
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• 제14권3호
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• pp.279-286
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• 2023

Background: This study aimed to evaluate the association between exposure to occupational hazards and the metabolic syndrome. A secondary objective was to analyze the additive and multiplicative effects of exposure to risk factors. Methods: This retrospective cohort was based on 31,615 health examinees at the Pusan National University Yangsan Hospital in Republic of Korea from 2012-2021. Demographic and behavior-related risk factors were treated as confounding factors, whereas three physical factors, 19 organic solvents and aerosols, and 13 metals and dust were considered occupational risk factors. Time-dependent Cox regression analysis was used to calculate hazard ratios. Results: The risk of metabolic syndrome was significantly higher in night shift workers (hazard ratio = 1.45: 95% confidence interval = 1.36-1.54) and workers who were exposed to noise (1.15:1.07-1.24). Exposure to some other risk factors was also significantly associated with a higher risk of metabolic syndrome. They were dimethylformamide, acetonitrile, trichloroethylene, xylene, styrene, toluene, dichloromethane, copper, antimony, lead, copper, iron, welding fume, and manganese. Among the 28 significant pairs, 19 exhibited both positive additive and multiplicative effects. Conclusions: Exposure to single or combined occupational risk factors may increase the risk of developing metabolic syndrome. Working conditions should be monitored and improved to reduce exposure to occupational hazards and prevent the development of the metabolic syndrome.

• The Korean Journal of Physiology and Pharmacology
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• 제23권6호
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• pp.467-474
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• 2019

Exposure to lead during pregnancy is a risk factor for the development of psychiatric disorders in the offspring. In this study, we investigated whether exposure to low levels of lead acetate (0.2%) in drinking water during pregnancy and lactation causes behavioral impairment and affects the expression of proteins associated with neurodevelopment. Lead exposure altered several parameters in rat offspring compared with those unexposed in open-field, social interaction, and pre-pulse inhibition tests. These parameters were restored to normal levels after clozapine treatment. Western blot and immunohistochemical analyses of the hippocampus revealed that several neurodevelopmental proteins were downregulated in lead-exposed rats. The expression was normalized after clozapine treatment (5 mg/kg/day, postnatal day 35-56). These findings demonstrate that downregulation of several proteins in lead-exposed rats affected subsequent behavioral changes. Our results suggest that lead exposure in early life may induce psychiatric disorders and treatment with antipsychotics such as clozapine may reduce their incidence.

• Structural Engineering and Mechanics
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• 제87권3호
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• pp.201-210
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• 2023

This paper investigates the flexural behavior of reinforced recycled aggregates concrete (RRAC) beams after exposed to high temperatures. The experimental results from 17 specimens were present and compared with temperatures, recycled coarse aggregate (RCA) replacement percentages, and concrete strength as variables. It was found that the high temperature would not cause an observable change in the failure pattern. However, high temperature can significantly reduce the stiffness and ductility, and accelerate the damage degradation of specimens. After exposure to 600℃, the ultimate bearing capacity of the specimens decreased by 20%-30% The mechanical properties of RRAC beams after high temperatures were barely impacted by the replacement percentages. Increasing the concrete strength of RCA could effectively improve the bearing capacity and peak deflection of RRAC beams after exposed to high temperatures. Furthermore, the calculation method of the bending bearing capacity and deflection of RRAC beams was also discussed.