• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.44.1-44.11
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• 2023

Background: A series of breast cancer cases were recently reported in a tertiary university hospital in South Korea. Nurses are generally exposed to risk factors for breast cancer such as night shift work, antineoplastic agents, and job strain. However, the epidemiological evidence of excess incidence among nurses remains lacking. This study aims to investigate the excess incidence of breast cancer among nurses in a tertiary university hospital and provide epidemiological evidence of occupational risk factors. Methods: A retrospective cohort was developed using personnel records of female workers in the nursing department who worked from January 2011 to June 2021 in a tertiary university hospital in South Korea. Sick leave records were used to identify cases of breast cancer. The standardized incidence ratio of breast cancer among nurses was compared to the general population. Results: A total of 5,509 nurses were followed up for 30,404 person-years, and 26 breast cancer cases were identified. This study revealed a significantly increased breast cancer incidence among all included nurses, with a standardized incidence ratio of 1.65 (95% confidence interval [CI]: 1.08-2.41), compared to the general population. Workers, who handle antineoplastic agents in their representative department and current and/or former department, had significantly elevated breast cancer standardized incidence ratios of 2.73 (95% CI: 1.008-5.94) and 3.39 (95% CI: 1.46-6.68), respectively. Conclusions: This study provides significant evidence of increased breast cancer risk among nursing staff in a hospital setting, particularly those who handle antineoplastic drugs. Measures that reduce exposure to risk factors should be implemented, especially anticancer drugs, to protect healthcare professionals. Further research at a national level that focuses on healthcare workers is necessary to validate breast cancer incidence and its contributing factors.

• Safety and Health at Work
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• v.15 no.3
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• pp.338-344
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• 2024

Background: Sickness presenteeism (SP) has gained attention in occupational health. This study aimed to analyze the relationship between SP and depressive symptoms by occupation and employment type during the COVID-19 pandemic in Korea. Methods: Community Health Survey data (August 16 to October 31, 2020-2021) were used to assess depressive symptoms and SP among workers (n = 221,241; mean age 46.0; 53.5% male). Depressive symptoms were measured using the Patient Health Questionnaire-9, and SP was defined by the ability to rest at home when exhibiting COVID-19 symptoms. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of depressive symptoms were estimated using multiple logistic regression analyses for each sex and year stratum. The interaction between SP and occupation on depressive symptoms was assessed using relative excess risk due to interaction (RERI). Results: The prevalence of depressive symptoms was higher in individuals with SP than in those without SP (4.22% [n = 696] vs. 1.89% [n = 3861], respectively). After adjusting for demographic and occupational variables, the association between SP and depressive symptoms was significant in both sexes in 2020 and 2021 (OR [95% CI]: 2.18 [1.82-2.62], 2.41 [1.97-2.93], 2.05 [1.77-2.38], 2.47 [2.11-2.88] for male-2020, male-2021, female-2020, and female-2021, respectively). A marginally significant interaction between service workers and SP on depressive symptoms was observed among male workers in 2021 (RERI = 2.37, 95% CI = [-0.04-4.78]) but not in other strata. Conclusion: SP is significantly associated with depressive symptoms in Korean workers across employment and occupational types, with a prominent association in service workers.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.185-190
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• 2004

Acute aquatic toxicity of effluents discharged from five dyeing plants in Gyeong-gi province were evaluated to assess whether the current Korean water quality standards(KWQS) could protect aquatic life. Chemical analyses of all parameters regulated under KWQS, except for E-coli, were also carried out to determine regulation compliance of the samples. All the effluent samples were satisfied with KWQS except for the color in only one sample. In acute Daphnia magna toxicity tests, significant mortality was observed in one of five samples and EC50 was 12.1%(95% confidence interval 9.1-16.2), which was in compliance with KWQS. The result of the Microtox assay indicated that acute microbial toxicity existed in effluents from three out of five plants, two of which were in compliance with KWQS. The agreement between regulation compliance of chemical concentrations of effluent and observed toxicity from various biological toxicity tests was very poor to fair (kappa = 0.194~0.250). The data presented suggest that exposure to dyeing wastewater which were in compliance with Korean water quality standards may not be safe to aquatic biota, and multiple tropical levels should be considered in aquatic toxicity monitoring of dyeing industry.

• Nutrition Research and Practice
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• v.17 no.5
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• pp.984-996
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• 2023

BACKGROUND/OBJECTIVES: Prior studies, mostly conducted in Western countries, have suggested that the low cost of energy-dense foods is associated with an increased risk of obesity. This study aimed to investigate the association between food costs and obesity risk among Koreans who may have different food cost and dietary patterns than those of Western populations. SUBJECTS/METHODS: We used baseline data from a cohort of 45,193 men and 83,172 women aged 40-79 years (in 2006-2013). Dietary intake information was collected using a validated food frequency questionnaire. Prudent and Western dietary patterns extracted via principal component analysis. Food cost was calculated based on Korean government data and market prices. Logistic regression analyses were performed to investigate the association of daily total, prudent, and Western food cost per calorie with obesity. RESULTS: Men in the highest total food cost quintile had 15% higher odds of obesity, after adjusting for demographic characteristics and lifestyle factors (adjusted odds ratio, 1.15; 95% confidence interval, 1.08-1.22; P-trend < 0.001); however, this association was not clear in women (P-trend = 0.765). While both men and women showed positive associations between prudent food cost and obesity (P-trends < 0.001), the association between Western food cost and obesity was only significant in men (P-trend < 0.001). CONCLUSIONS: In countries in which consumption of Western foods is associated with higher food costs, higher food costs are associated with an increased risk of obesity; however, this association differs between men and women.

• Tuberculosis and Respiratory Diseases
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• v.87 no.3
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• pp.309-318
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• 2024

Background: There is limited data regarding the clinical outcomes of clonal hematopoiesis of indeterminate potential (CHIP) in patients with chronic obstructive pulmonary disease (COPD). This study aimed to evaluate the clinical significance of CHIP as a COPD biomarker. Methods: This retrospective study was conducted on patients with COPD who were enrolled prospectively in the Seoul National University Hospital Airway Registry from January 2013 to December 2019 and underwent pulmonary function and blood tests. We evaluated the CHIP score according to smoking status and severity of airflow obstruction. Results: We analyzed next-generation sequencing data to detect CHIP in 125 patients with COPD. Current smokers had a higher prevalence of CHIP in combination of DNMT3A, TET2, and PPM1D (DTP), DNA methyltransferase 3 alpha (DNMT3A), and protein phosphatase, Mg²⁺/Mn²⁺ dependent 1D (PPM1D) genes than in never- or ex-smokers. CHIP of DTP and DNMT3A genes was significantly associated with current smokers (adjusted odds ratio [aOR], 2.80; 95% confidence interval [CI], 1.01 to 7.79) (aOR, 4.03; 95% CI, 1.09 to 14.0). Patients with moderate-to-severe airflow obstruction had a higher prevalence of CHIP in most of the explored genes than those with mild obstruction, although the difference was not statistically significant. CHIP in ASXL transcriptional regulator 1 (ASXL1) genes was significantly associated with history of mild, severe, and total acute exacerbation. Conclusion: Given that CHIP in specific genes was significantly associated with current smoking status and acute exacerbation, CHIP can be considered as a candidate biomarker for COPD patients.

• Korean Journal of Radiology
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• v.21 no.6
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• pp.707-716
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• 2020

Objective: To evaluate pharmacokinetic variables from contrast-enhancing lesions (CELs) and non-enhancing T2 high signal intensity lesions (NE-T2HSILs) on dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging for predicting progression-free survival (PFS) in glioblastoma (GBM) patients. Materials and Methods: Sixty-four GBM patients who had undergone preoperative DCE MR imaging and received standard treatment were retrospectively included. We analyzed the pharmacokinetic variables of the volume transfer constant (Ktrans) and volume fraction of extravascular extracellular space within the CEL and NE-T2HSIL of the entire tumor. Univariate and multivariate Cox regression analyses were performed using preoperative clinical characteristics, pharmacokinetic variables of DCE MR imaging, and postoperative molecular biomarkers to predict PFS. Results: The increased mean Ktrans of the CEL, increased 95th percentile Ktrans of the CELs, and absence of methylated O⁶-methylguanine-DNA methyltransferase promoter were relevant adverse variables for PFS in the univariate analysis (p = 0.041, p = 0.032, and p = 0.083, respectively). The Kaplan-Meier survival curves demonstrated that PFS was significantly shorter in patients with a mean Ktrans of the CEL > 0.068 and 95th percentile Ktrans of the CEL > 0.223 (log-rank p = 0.038 and p = 0.041, respectively). However, only mean Ktrans of the CEL was significantly associated with PFS (p = 0.024; hazard ratio, 553.08; 95% confidence interval, 2.27-134756.74) in the multivariate Cox proportional hazard analysis. None of the pharmacokinetic variables from NE-T2HSILs were significantly related to PFS. Conclusion: Among the pharmacokinetic variables extracted from CELs and NE-T2HSILs on preoperative DCE MR imaging, the mean Ktrans of CELs exhibits potential as a useful imaging predictor of PFS in GBM patients.

• Health Policy and Management
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• v.27 no.3
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• pp.247-255
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• 2017

Background: South Korea has experienced problems with excessive pharmaceutical expenditures. In 2010, the South Korean government introduced an outpatient prescription incentive program to effectively manage pharmaceutical expenditures. Therefore, we examined the relationship between the outpatient prescription incentive program and pharmaceutical expenditures. Methods: We used data from the Korean National Health Insurance claims database, which included medical claims filed for 22,732 clinics from 2011-2014 to evaluate associated pharmaceutical expenditures. We performed multiple regression analysis and Poisson regression analysis using generalized estimating equation models to examine the associations between outpatient prescription incentives and the outcome variables. Results: The data used in this study consisted of 123,392 cases from 22,372 clinics (average 5.4 periods follow-up). Clinics that had received outpatient prescription incentives in the last period had better cost saving and Outpatient Prescribing Costliness Index (OPCI) (received: proportion of cost saving, ${\beta}=6.8179$; p-value < 0.0001; OPCI, ${\beta}=-0.0227$; p-value < 0.0001; reference = non-received). Moreover, these clinics had higher risk in the provision of outpatient prescription incentive (relative risk, 2.772; 95% confidence interval, 2.720 to 2.824). The associations were higher in clinics that had separate prescribing and dispensing programs, or had professional staff. Conclusion: The introduction of an outpatient prescription incentive program for clinics effectively managed problems with rapid increases of pharmaceutical expenditures in South Korea. However, the pharmaceutical expenditures still increased in spite of the positive impact of the outpatient prescription incentive program. Therefore, healthcare professionals and health policy makers should develop more effective alternatives (i.e., for clinics without separate prescribing and dispensing programs) based on our results.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.102-105
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• 1991

In recognition of the transportation problems of the present and to prepare for the ever increasing demands of the future, government decided to develop the magnetically levitated train domestically and started R&D program office in Korea Institute of Machinery and Metals(KIMM). This office since has established three step by step goals : first to develop a 40 passenger exhibition vehicle for Daejon EXPO'93, second to develop the low to mid-speed maglev system for urban public transportation by 1997 and finally the high speed inter-city maglev train by year 2001. The first two maglev systems will use attractive levitation-LIM driven technologies and these technologies are the ones currently being developed by this office and others. The maglev train system is a product of wide range of technologies from electro-technologies to civil engineering technologies. Some of the technologies are currently available but more have to be developed in the near future and these technologies are owned by or to be developed by various institutions within the science & technology community. The level of the technologies available at the present time are still very rudimentary and their basis are very narrow. Recently we have made a few successes in terms of levitation and propulsion but they are only with small scale modules and results are very qualitative at best. A great deal of development work has yet to be done to refine the technologies and to gain confidence. Full scale levitation/propulsion modules will be tested on the curved guideway within 6 months by this office and another institution. This paper reviews the current status of the maglev technologies in Korea and discuss the development strategies. The Korean maglev program is very ambitious and the schedule is even more so. A steady financial support and strong system engineering and integration are essential to the success of this program.

• Publications of The Korean Astronomical Society
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• v.33 no.2
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• pp.9-19
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• 2018

We investigate the life of Lee Cheon (1376-1451) who was closely connected with astronomy during the reign of King Sejong of the Joseon dynasty. Lee Cheon is widely regarded as one of the outstanding scientists of King Sejong's period. However, his contributions to the development of the astronomy during the period have not been enlightened. Based on the historical records on the life and achievements of Lee Cheon, mainly referring to the Joseonwangjosillok (Annals of the Joseon Dynasty), we address three important points. First, Lee Cheon was a distinguished administrator who filled various government posts. Second, he was a supervising engineer in public works and metal smelting during his position in military. Third, he was a scientific technician and manufactured precision equipment such as the metal movable type sets. By virtue of these aspects, Lee Cheon was taken into confidence by King Sejong on the Ganui-dae project (i.e., manufacture various astronomical instruments and construct their platform in order to make a calendar suitable for Joseon). During the period of this project, Lee Cheon not only supervised the construction of the Ganui (simplified armillary sphere) and Ganui-dae (platform for astronomical instruments) but also participated in the production of the astronomical instruments such as Gyupyo (Gnomon) and Honcheonui (Armillary Sphere). In conclusion, we regard Lee Cheon as one of the astronomers who led a great advance in astronomy during King Sejong's era.

• Korean Parent-Child Health Journal
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• v.16 no.1
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• pp.11-16
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• 2013

Purpose: Ethiopia is one of the sub-Saharan countries most affected by high maternal and infant mortality. The government has trained health extension workers (HEWs), the community health workers, to deliver preventive and basic curative health services to community residents in Ethiopia. Very few studies have investigated on-the-job educational effects for HEWs on improvement of their knowledge and performance confidence in maternal and child health care (MCH). This study aimed at identifying the educational effects for HEWs in one health center in Tigray, Ethiopia on improvement of their knowledge in MCH. Methods: Twelve HEWs from 6 health posts participated in this study. A health center officer provided a total of 5 educational sessions on antenatal and postnatal care, family planning, and newborn care from August, 2012 to April, 2013. Ten to 12 items regarding the topics were tested before and after each education. Wilcoxon signed rank test was used to analyze the data. Results: All the HEWs were female with average 4-year working experience. Their knowledge significantly increased after education, except the first session. Their satisfaction on education was greater than 45 points out of 50. Conclusion: This study suggests a focused education for HEWs should continue to improve their capacity on MCH.