• Journal of the Korean Society for Railway
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• v.12 no.5
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• pp.793-799
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• 2009

Using transportations like railway, aviations and roads have been increasing continuously. Traffic accidents have been increasing as well. To prevent or lessen these accidents become a big issue to solve. Therefore, more enforced safety levels are being required to meet. In railway field, continuous efforts of railway safety are being executed to prevent traffic accidents. In present, railway accidents have been decreasing since subway accident happened in Daegu Subway in 2003. However, safety levels in railway field have not yet achieved as much as in advanced countries. Basic concept for enforced safety level in railway system is to prevent or minimize accidents by managing systems like related facilities, management method, organization, education. This is the same concept to minimize error rate in six sigma theory. In this paper, we are to apply six sigma techniques used in manufacturing industry to railway safety and go through ways to make more efficient railway safety system.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.178-186
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• 2014

Background: This study was conducted to assess health risks in regard to exposure by children to volatile organic compounds (VOCs) in children's products. Methods: Ten VOCs were measured by head-space gas chromatography in children's products, including toys, oil pastels, sign pens, furniture, ball pools, and playmats. We estimated the average daily dose (ADD) via inhalation during the use of these children's products and calculated hazard quotient (HQ) by dividing ADD by reference dose of VOCs. Results: Among the measured VOCs, five compounds were identified in children's products: benzene, ethylbenzene, styrene, toluene, and xylene. The detection rates of VOCs in toys, ball pools, furniture, playmats, sign pens, and oil pastels were 85%, 100%, 100%, 30%, 100%, and 60%, respectively. The maximum levels of VOCs were 0.18 mg benzene/kg in toys, 5.92 mg toluene/kg in playmats, 10.37 mg ethylbenzene/kg in ball pools, 24.85 mg xylene/kg in toys, and 118.29 mg styrene/kg in ball pools. From exposure levels of VOCs in the children's products HQs were calculated within a range of $5.71{\times}10^{-10}$ to $4.77{\times}10^{-4}$. The HQ of xylene was the highest for children aged 0-6 playing on the playmats. However, the HQ via inhalation exposure to VOCs in individual products did not exceed 1.00. Conclusion: Based on the results, it was concluded that the use of these children's products do not pose health risks to children.

• Journal of Preventive Medicine and Public Health
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• v.51 no.6
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• pp.298-309
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• 2018

Objectives: The objective of this study was to assess the relationship between systolic and diastolic blood pressure (SBP, DBP) and the risk of death from specific causes other than cardiovascular diseases. Methods: We calculated the risk of specific death by SBP and DBP categories for 506 508 health examinees in 2002-2003 using hazard ratios (HRs) and 95% confidence intervals (CIs) in a Cox proportional hazards model. Results: Compared to normal levels (SBP <120 or DBP <90 mmHg), stage I systolic and diastolic hypertension (SBP 140-159, DBP 85-89 mmHg, respectively) were associated with an increased risk of death from diabetes mellitus, alcoholic liver disease, and renal failure (HR, 1.83; 95% CI, 1.51 to 2.22; HR, 1.24; 95% CI, 1.06 to 1.46; HR, 2.30; 95% CI, 1.64 to 3.21; HR, 1.67; 95% CI, 1.27 to 2.20; HR, 1.99; 95% CI, 1.41 to 2.81; HR, 1.31; 95% CI, 0.99 to 1.73, respectively), but a decreased risk of death from intestinal pneumonia (HR, 0.64; 95% CI, 0.42 to 0.98; HR, 0.59; 95% CI, 0.39 to 0.91). Only stage II systolic hypertension (SBP ${\geq}160mmHg$) was associated with an increased risk of death from pneumonia, liver cirrhosis, and intestinal ischemia (HR, 1.54; 95% CI, 1.19 to 1.98; HR, 1.46; 95% CI, 1.00 to 2.15; HR, 3.77; 95% CI, 1.24 to 11.40, respectively), and stage I and II diastolic hypertension (SBP 140-159 and ${\geq}160mmHg$) were associated with an increased risk of death from intestinal ischemia (HR, 3.07; 95% CI, 1.27 to 7.38; HR, 4.39; 95% CI, 1.62 to 11.88, respectively). Conclusions: An increase in blood pressure levels may alter the risk of death from certain causes other than cardiovascular diseases, a well-known outcome of hypertension, although the mechanism of these associations is not well documented.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.19-26
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• 2019

The objective of this study was to analyze bacteriological and chemical hazards in minimally processed commercial fish products, including Hwangtae (freeze-dried pollock), dried anchovy, fermented anchovy sauce, and salted and dried yellow croaker. Escherichia coli counts from all samples were below the regulation limits of the Korean Ministry of Food and Drug Safety Standards on Quality of Seafood and Seafood Products (Food Code). However, the food poisoning bacterium Staphylococcus aureus was detected at levels above $1.0{\times}10^2$ colony forming units (CFU)/g in Hwangtae, dried anchovy, and salted and dried yellow croaker, which are commonly ingested without heating and pose bacteriological hazards. The detection of S. aureus, an organism indicative of poor personal hygiene, which can be introduced by employees and multiply during distribution, indicates the necessity of improving the sanitary control of minimally processed commercial fish products. Histamine was not detected from dried anchovy or salted and dried yellow croaker, but was detected at some of the highest levels in fermented anchovy sauces. This result suggests that efforts to reduce the amount of histamine in fermented anchovy sauces are required.

• Safety and Health at Work
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• v.12 no.1
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• pp.119-126
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• 2021

Background: During the period 2001 to 2016, the maximum temperatures in Thailand rose from 38-41℃ to 42-44℃. The current occupational heat exposure standard of Thailand issued in 2006 is based on wet bulb globe temperature (WBGT) defined for three workload levels without a work-rest regimen. This study examined whether the present standard still protects most workers. Methods: The sample comprised 168 heat acclimatized workers (90 in construction sites, 78 in foundries). Heart rate and auditory canal temperature were recorded continuously for 2 hours. Workplace WBGT, relative humidity, and wind velocity were monitored, and the participants' workloads were estimated. Heat-related symptoms and signs were collected by a questionnaire. Results: Only 55% of the participants worked in workplaces complying with the heat standard. Of them, 79% had auditory canal temperature ≤ 38.5℃, compared with only 58% in noncompliant workplaces. 18% and 43% of the workers in compliant and noncompliant workplaces, respectively, had symptoms from heat stress, the trend being similar across all workload levels. An increase of one degree (C) in WBGT was associated with a 1.85-fold increase (95% confidence interval: 1.44-2.48) in odds for having symptoms. Conclusion: Compliance with the current occupational heat standard protects 4/5 of the workers, whereas noncompliance reduces this proportion to one half. The reasons for noncompliance include the gaps and ambiguities in the law. The law should specify work/rest schedules; outdoor work should be identified as an occupational heat hazard; and the staff should include occupational personnel to manage heat stress in establishments involving heat exposure.

• Journal of Nutrition and Health
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• v.54 no.4
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• pp.342-354
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• 2021

Purpose: Obesity is a serious public health issue for the modern society and is considered a chronic health hazard. There are many surgical and pharmacological approaches to treat obesity. However, various potentially hazardous side effects remain the biggest challenge. Therefore, diets based on foods derived from natural products have gained increasing attention compared to anti-obesity drugs. Recently, research on edible insects as a food source has been a topic of considerable interest in the scientific communities. This study examined the anti-obesity effects of ingesting an edible insect by feeding a high-fat diet (HFD)-induced obese mouse models with a diet containing Tenebrio molitor larvae powder (TMLP). Methods: Six-week-old female C57BL/6J mice were divided into 4 groups according to treatment: 100% normal diet (ND), 100% HFD (HFD), HFD 99% + TMLP 1% (TMLP), and HFD 97% + TMLP 3% (TMLP 3%). TMLP was added to the HFD for 6 weeks for the latter two groups. Results: Compared to the HFD group, mice in the TMLP group showed weight loss, and micro-computed tomographic imaging revealed that the volume of the adipose tissue in the abdominal area also showed significant reduction. After an autopsy, the fat weight was found to be significantly reduced in the TMLP group compared to the HFD group. In addition, the degree of fat cell deposition in the liver tissue and the size of the adipocytes significantly decreased in the TMLP group. Reverse transcription polymerase chain reaction analysis for the mRNA expression of adipogenesis-related genes namely CCAAT-enhancer-binding proteins (C/EBP-β, C/EBP-δ), and fatty acid-binding protein 4 (FABP4) showed that the expression levels of these genes were significantly reduced in the TMLP group compared to the HFD group. Serum leptin level also decreased significantly in the TMLP group in the comparison with the HFD group. In addition, total cholesterol, triglyceride, and glucose levels in mouse serum also decreased in the TMLP group. Conclusion: Taken together, our results showed that TMLP effectively inhibited adipocyte growth and reduced body weight in obese mice.

• Earthquakes and Structures
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• v.24 no.1
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• pp.37-51
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• 2023

Türkiye has made significant changes and updates in both seismic risk maps and design codes over time, as have other countries with high seismic risk. In this study, the last two seismic design codes and risk maps were compared for the Aegean Region (Western Türkiye) where the earthquake risk has once again emerged with the 2020 Izmir Earthquake (Mw=6.9). In this study, information about the seismicity of the Aegean Region was given. The seismic parameters for all provinces in the region were compared with the last two earthquake risk maps. The spectral acceleration coefficients of all provinces have increased and differentiated with the current seismic hazard map as a result of the design spectra used on a regional basis have been replaced by the geographical location-specific design spectra. In addition, section damage limits were obtained for all provinces within the scope of the last two seismic design codes. Structural analyses for a sample reinforced-concrete building were made separately for each province using pushover analysis. The deformations in the cross-sections were compared with the limit states corresponding to the damage levels specified in the last two seismic design codes for the region. Target displacement requests for all provinces have decreased with the current code. The differentiation of geographical location-specific design spectra both in the last two seismic design code and between provinces has caused changes in section damages and building performance levels. The main aim of this study is to obtain and compare both seismic and structural analysis results for all provinces in the Aegean Region (Western Türkiye).

• Korean Circulation Journal
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• v.52 no.12
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• pp.878-886
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• 2022

Background and Objectives: Moderate aortic stenosis (AS) confers a surprisingly adverse prognosis, approaching that of severe AS. The objective of this study was to describe the clinical course of patients with moderate AS with evidence of concomitant heart failure manifesting as elevated brain natriuretic peptide (BNP) levels. Methods: This is a single-center, retrospective cohort study of 332 patients with elevated BNP. 165 patients with moderate AS were compared with 167 controls with none-mild AS. The Median follow-up duration was 3.85 years. The primary outcome was a composite endpoint of all-cause hospitalizations and all-cause mortality. Results: BNP levels were 530 and 515 pg/mL in the study and the control groups, respectively. Moderate AS had significantly higher rates of primary composite endpoint in both univariate analysis (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.14-1.97; p=0.004) and adjusted analysis (HR, 1.45; 95% CI, 1.05-2.01; p=0.02). Moderate AS had 1.41 (95% CI, 1.18-1.69; p<0.001) times more all-cause hospitalization per patient-year of follow-up compared to controls in the univariate model. After adjustment for significant covariates, moderate AS remained an independent predictor of all-cause hospitalizations (incidence rate ratio [IRR], 1.45; 95% CI, 1.18-1.79; p=0.005). Furthermore, moderate AS was significantly associated with higher all-cause hospitalization rates in both heart failure with reduced ejection fraction (IRR, 1.33; 95% CI, 1.02-1.75; p=0.038) and heart failure with preserved ejection fraction [IRR], 1.31; 95% CI, 1.03-1.67; p=0.026). Conclusions: Moderate AS in conjunction with elevated BNP portends a significantly worse prognosis than those without moderate AS and should be followed closely.

• Korean Journal of Agricultural Science
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• v.51 no.2
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• pp.109-121
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• 2024

Mancozeb is a manganese and zinc-containing fungicide that belongs to the ethylene bisdithiocarbamate group and produces ethylene thiourea (ETU) after biotransformation or environmental degradation, which has toxicological hazard owing to its known antithyroid properties. Although mancozeb leads to negative changes in fertility capacity, the effects of ETU are less known. Therefore, this study examined the alteration of fertilization competence in boar spermatozoa exposed to ETU. The sperm motility, motion kinematics, viability, acrosome integrity, chromatin stability, and intracellular reactive oxygen species (ROS) production of sperm subjected to various ETU concentrations (10, 50, 100, and 200 µM) were evaluated after two different incubation times (30 min and 2 hrs). In addition, the relative mRNA expression of the sperm functional proteins was analyzed after exposure to ETU. A dose-dependent motility reduction was observed in sperm exposed to ETU during both incubation periods compared to the controls. The motion kinematics were reduced significantly in sperm incubated with ETU. Higher percentages of viable sperm were observed in the controls, while such viability was decreased significantly in sperm with 10 - 200 µM ETU. The acrosome integrity was particularly damaged on sperm incubated with 10 - 200 µM ETU for 30 min. Higher intracellular ROS levels were produced in sperm exposed to 200 µM ETU. In addition, lower relative levels of AKAP3, AKAP4, ODF2, and ZPBP2 expression were observed in sperm exposed to ETU compared to the controls. Mancozeb and ETU could adversely affect the reproductive functions of mammals. Hence, the effects of ETU on the reproductive system should be examined further.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.104-110
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• 2013

This study assessed hazards at the harvest stage of strawberry farms which may cause risk to humans. A total of 216 samples were collected from 6 strawberry farms (soil culture farms: A, B, C; nutriculture farms: D, E, F) located in Western Gyeongnam. The collected samples were subjected for sanitary indicator bacteria (aerobic plate count, coliforms and Escherichia coli), major foodborne pathogens (E. coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus and Bacillus cereus), and fungi. The levels of APC and coliform in the soil culture farms were 1.0-6.9 and 0.4-4.6 log CFU/g (leaf, mL, hand or 100 $cm^2$), respectively. The samples obtained from the nutriculture farms were contaminated with the levels of 0.8-4.9, and 0.2-2.6 log CFU/g (leaf, mL, hand or 100 $cm^2$) of APC and coliform. However, E. coli was not detected in any samples. In major foodborne pathogens, S. aureus was detected at the level of ${\leq}$3.3 log CFU/hand in workers' hand samples and B. cereus was detected at the levels of 0.4-4.1 log CFU/g (hand or 100 $cm^2$) in soil, plants and workers' hygiene. L. monocytogenes, E. coli O157:H7 and Salmonella spp. were not detected. Fungi were detected at the levels of 1.0-5.2 and 0.2-4.4 log CFU/g (leaf, mL, hand or 100 $cm^2$) in soil culture and nutriculture farms, respectively.