• Fashion & Textile Research Journal
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• v.15 no.3
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• pp.452-460
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• 2013

This study conducted a performance evaluation of protective clothing materials used for welding in a hazardous shipbuilding industry work environment. The welding process was selected as the one that most requires industrial protective clothing according to work environment characteristics. Flame proofing and convection heat protection performance (HTI) in the heat transfer characteristics of protective clothing material were indicated in the order of SW1(Oxidant carbon)>SW2(silica coated Oxidant carbon)>SW4(Oxidant carbon/p-aramid)>SW3(flame proofing cotton). However, radiant heat protection performance (RHTI) and the heat transfer factor (TF) were indicated in the order of SW1>SW4>SW2>SW3 and showed different patterns from the convection heat protection performance. SW1 showed superior air permeability and water vapor permeability. The tensile strength and tear strength of welding protective clothing material were indicated in the order of SW4>SW2>SW3>SW1 and showed that a blend fabric of p-aramid was the most superior for the mechanical properties of SW4. SW1 had excellent heat transfer properties in yet met the minimum performance requirements of tensile strength proved to be inappropriate as being a material for welding protective clothing. The abrasion resistance of woven fabric proved superior compared to nonwoven fabric; however, seam strength and dimensional change both met the minimum performance requirements and indicated that all samples appeared non-hazardous. Finally, oxidant carbon/p-aramid blend fabric appeared appropriate as a protective clothing materials for welding.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.2
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• pp.38-43
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• 2019

Electrochemical etching is a popular process to apply metal patterning in various industries. In this study, the electrochemical etching using a patterned copper layer was proposed to fabricate multilayered structures. The process consists of electrodeposition, laser patterning, and electrochemical etching, and a repetition of this process enables the production of multilayered structures. In the fabrication of a multilayered structure, an etch factor that reflects the etched depth and pattern size should be considered. Hence, the etch factor in the electrochemical etching process using the copper layer was calculated. After the repetition process of electrochemical etching using copper layers, the surface characteristics of the workpiece were analyzed by EDS analysis and surface profilometer. As a result, multilayered structures with various shapes were successfully fabricated via electrochemical etching using copper layers.

• Research in Community and Public Health Nursing
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• v.14 no.2
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• pp.253-262
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• 2003

Purpose: This study was carried out to identify factors influencing osteoporosis in women at pre- and post-menopausal state. Methods: The subjects of this study were 52 pre-menopausal and 125 post-menopausal women who were assessed of bone density in one general hospital. The data were collected through review of clinical records and telephone interviews using a questionnaire. Results: In the pre-menopausal women, the factors influencing osteoporosis were regular exercise (protective factor) and age (risk factor). Regression analysis showed that the factors attributable to osteoporosis included educational level, weight, age and number of pregnancy, accounted for 41.89% of the total variance. In the post-menopausal women. the factors influencing osteoporosis were age (risk factor), low educational level (risk factor), low economical state (risk factor), high parity (risk factor), and intake of coffee (protective factor). Regression analysis also showed that factors attributable to their osteoporosis included age, educational level, number of delivery, intake of the coffee, regular exercise, number of pregnancy and duration of oral pill intake, accounted for 37.41 % of the total variance. Conclusion: In pre-menopausal women, regular exercise was one of the most powerful determinant of their bone mass. Therefore, it is necessary to participate in a regular exercise program to maintain peak bone mass density prior to the onset of menopause. In post-menopausal women, increased age was the most influencing factor of their bone mass. Therefore, it is essential to establish early diagnosis and management of osteoporosis after menopause.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.5
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• pp.495-495
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• 2021

• Journal of Korean Medicine for Obesity Research
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• v.20 no.1
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• pp.10-19
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• 2020

Objectives: Oxidative stress-mediated neuroinflammation has been supposed as a crucial factor that contributes to the pathogenesis of many neurodegenerative diseases. In this study, we aimed to investigate the protective activity against oxidative stress and neuroinflammation of protocatechuic acid (PA), active phenolic compound from Momordica Charantia. Methods: Protective activity of PA from oxidative stress was performed under in vitro conditions. Our study investigated the protective mechanism of PA from neuroinflammation in cellular system using C6 glial cell. To investigate the improvement the effects on oxidative stress and neuroinflammation, we induced oxidative stress by H₂O₂ (100 μM) stimulation and induced neuroinflammation by treatment with lipopolysaccharide (LPS) (1 ㎍/mL) and interferon-gamma (IFN-γ) (10 ng/mL) in C6 glial cells. Results: PA showed strong radical scavenging effect against 1,1-dipenyl-2-picrylhydrazyl, hydroxy radical (·OH) and nitric oxide (NO). Under oxidative stress treated by H₂O₂, the result showed the increased mRNA expressions of oxidative stress markers such as nuclear factor-kappaB (NF-κB), cyclooxygenase (COX-2) and inducible nitric oxide (iNOS). However, the treatment of PA led to reduced mRNA expressions of NF-κB, COX-2 and iNOS. Moreover, PA attenuated the production of interleukin-6 and scavenged NO generated by both endotoxin LPS and IFN-γ together. Furthermore, it also reduced LPS and IFN-γ-induced mRNA expressions of iNOS and COX-2. Conclusions: In conclusion, our results collectively suggest that PA, phenolic compound of Momordica Charantia, could be a safe anti-oxidant and a promising anti-neuroinflammatory molecule for neurodegenerative diseases.

• Anxiety and mood
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• v.18 no.2
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• pp.80-91
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• 2022

Objective : Hospital workers' mental health has deteriorated because of the ongoing COVID-19 pandemic. The purpose of this study was to investigate the impact of the prolonged COVID-19 pandemic on the mental health of hospital workers and its determinants. Methods : Two surveys were conducted among employees working in a hospital that received COVID-19 patients from the early phase of the pandemic in South Korea. Data on demographics, perceived threat, workplace evaluation, resilience, and mental health status were collected using the Korean General Health Questionnaire-20 in the initial phase (February 2020) and during the third wave of COVID-19 (December 2020) for 467 and 545 workers, respectively. The mental health of hospital workers in the two phases was compared, and the risk and protective factors during the third wave were investigated. Results : The proportion of patients in the psychiatric high-risk group increased from 2.8% in the initial phase to 11.4% during the third wave. The perceived threat, workplace evaluation, and resilience of respondents deteriorated. Risk factors for mental health during the third wave included the perceived threat items of job stress, loss of control, and considering resignation. Protective factors included presence of children, workplace satisfaction, and hardiness in resilience. Conclusion : Hospital workers' mental health deteriorated as the pandemic progressed. General stress and tension such as job stress, loss of control, considering resignation rather than COVID-19-specific stress had negative effects on mental health of hospital workers. Therefore, care for work stress itself can be helpful to maintain the mental health of hospital workers. Also, governance to improve workplace satisfaction or hardiness in resilience can be a potential protective factor for hospital workers' mental health during the prolonged pandemic.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.57-64
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• 2013

Objectives: Skin exposure to diisocyanates may be an important risk factor for respiratory sensitization to leading asthma. However little is known about the extent of worker's diisocyanates skin exposure and the effectiveness of personal protective equipments in polyurethane foam manufacturing companies. This study provides data on diisocyanates skin exposure, surface diisiocyantes contamination of foams and the effectiveness of personal protective gloves in five polyurethane foam manufacturing companies. Materials and methods Colorimetric SWYPE pads are used for the determination of diisocyanates on surfaces of workers skin and polyurethanes foams. Results: The forearms, necks and faces of workers in polyurethane foam manufacturing companies were found to be contaminated with diisocyanates. Heavy contamination with uncured diisocyanates at large block foams surfaces were found. Personal gloves of workers for skin protection showed significant penetrations by diisocyanates. Conclusions: We found that all workers in polyurethane foam manufacturing companies could be exposed to diisocyanates by skin exposure. Also further researches which would better quantify skin exposure are needed.

• Toxicological Research
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• v.30 no.1
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• pp.45-48
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• 2014

Helicobacter pylori (H. pylori) is the most important factor of gastric disease in clinical practice. Moreover, smoking, stress and a poor diet may be additive factors for gastric damage. With these factors, increasing infection of H. pylori triggers gastritis, gastric ulcers and gastric cancer. To develop a new protective agent, we are concerned with plant-derived extract. The extract of Coptis chinensis (C. chinensis) and its constituents were investigated to assess their protective activities against gastric damage. The C. chinensis extract showed a scavenging effect against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals, inhibition of H. pylori colonization and antiulcerogenic activities in rat. In particular, palmatine derived from C. chinensis was found to be the novel protective agent. It is better than the C. chinensis extract, berberine, a well-known constituent of C. chinensis. We suggest that palmatine from the root cortex of C. chinensis may be a good candidate for the development of new pharmaceuticals to prevent gastric disease.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.12
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• pp.6-12
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• 2014

The safety and reliability of the power system short-circuit current, the short-circuit current depends on the failure to obtain the objective is to quickly eliminate the breaking capacity of the circuit-breaker selection of the cable, the insulation of electrical equipment and protective relay an important factor in determining the level correction and protective relay selection scheme to be meaningful. Standards used in the domestic circuit breaker is applied to the production of IEC standard, but the American National Standards (ANSI / IEEE) by NEMA specification of the fault current calculations and the application of the asymmetric coefficient Korea. Therefore, in this paper, the IEC 60909 standard IEC breaker fault current calculation method and the method for selection of system configurations reviewed and protection system for reviewing the configuration of various protective relays appropriate correction and the correction value is main protection, back-up protection the equipment so that the period of protection relay coordination to minimize accidents and accident protection to minimize interruptions proposed for cooperation.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.436-446
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• 2018

Background: The potential therapeutic values of Korean Red Ginseng extract (KRGE) in autoimmune disorders of nervous system have not been fully investigated. Methods: We used an acute experimental autoimmune encephalomyelitis animal model of multiple sclerosis and determined the effects and mechanism of KRGE on spinal myelination. Results: Pretreatment with KRGE (100 mg/kg, orally) for 10 days before immunization with myelin basic protein $(MBP)_{68-82}$ peptide exerted a protective effect against demyelination in the spinal cord, with inhibited recruitment and activation of immune cells including microglia, decreased mRNA expression of detrimental inflammatory mediators (interleukin-6, interferon-${\gamma}$, and cyclooxygenase-2), but increased mRNA expression of protective inflammatory mediators (insulin-like growth factor ${\beta}1$, transforming growth factor ${\beta}$, and vascular endothelial growth factor-1). These results were associated with significant downregulation of p38 mitogen-activated protein kinase and nuclear factor-${\kappa}B$ signaling pathways in microglia/macrophages, T cells, and astrocytes. Conclusion: Our findings suggest that KRGE alleviates spinal demyelination in acute experimental autoimmune encephalomyelitis through inhibiting the activation of the p38 mitogen-activated protein kinase/nuclear factor-${\kappa}B$ signaling pathway. Therefore, KRGE might be used as a new therapeutic for autoimmune disorders such as multiple sclerosis, although further investigation is needed.