• Journal of Korean Clinical Nursing Research
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• v.27 no.2
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• pp.165-178
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• 2021

Purpose: To analyze nurses' shift work according to the government guidelines for night work and their perceptions of their work schedules. Methods: The study sample included 487 nurses who provided information on their schedules, including the normal working hours of each shift, and overtime per shift during September 2020. Nurses' perceptions were measured in terms of satisfaction, appropriateness for work-life balance, and fairness to their work schedule. Results: One-third of the respondents worked more than 40 hours per week. The average overtime hour was 1.14 hours per shift. Unsocial hours (8 pm to 6 am on weekdays, midnight to midnight on weekends and public holidays) accounted for 56.4% of all working hours. During their last night shift, on average, nurses worked 9.62 hours and had a break of 39 minutes, although 20.5% reported no break. Sixty-eight percent of nurses had at least one between-shift break shorter than 48 hours after a consecutive night shifts. Fifty-seven percent were satisfied with their schedule. One-third perceived their schedule as appropriate for work-life balance, and two-thirds perceived that days off on weekends and nights were fairly distributed within the unit. Working and overtime hours had an inverse relationship with all three aspects of nurses' perceptions. A higher proportion of unsocial hours and having no breaks during the night shift were associated with lower perceptions of fairness. Conclusion: Reducing working hours, ensuring breaks during night shifts, and increasing rewards for unsocial hours are required to improve nurses' perceptions and reduce turnover due to shift work.

• Korean Journal of Veterinary Service
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• v.44 no.4
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• pp.195-207
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• 2021

Species A rotaviruses (RVAs) replicate and assemble their immature particles within electron dense compartments known as viroplasms, where lipid droplets (LDs) interact with the viroplasm and facilitate viral replication. Despite the importance of LD formation in the life cycle of RVAs, the upstream molecules modulating LD formation remain unclear. This study aimed to find out the role of sterol regulatory element-binding proteins (SREBPs) in reprogramming of LD formation after RVA infection. Here, we demonstrate that RVA infection reprograms the sterol regulatory element-binding proteins (SREBPs)-dependent lipogenic pathways in virus-infected cells, and that both SREBP-1 and -2 transactivated genes, which are involved in fatty acid and cholesterol biosynthesis, are essential for LD formation. Our results showed that pharmacological inhibition of SREBPs using AM580 and betulin and inhibition of their downstream cholesterol biosynthesis (simvastatin for HMG-CoA reductase) and fatty acid enzymes (TOFA) negatively modulated the intracellular triacylglycerides and cholesterol levels and their resulting LD and viroplasm formations. Interestingly, pharmacological inhibition of SREBPs significantly reduced RVA protein synthesis, genome replication and progeny production. This study identified SREBPs-mediated lipogenic reprogramming in RVA-infected host cells, which facilitates virus replication through LD formation and its interaction with viroplasms, suggesting that SREBPs can be a potential target for the development of efficient and affordable therapeutics against RVA infection.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.2
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• pp.153-162
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• 2022

Objectives: Fused deposition modeling (FDM) 3D printer which is one of the material extrusion (MEX) technologies is an additive manufacturing (AM) process. 3D printers have been distributed widely in Korea, particularly in school and office, even at home. Several studies have shown that nanoparticles and volatile organic compounds (VOCs) were emitted from an FDM 3D printing process. The objective of this study was to identify types of chemicals possibly emitted from FDM 3D printing materials such as PLA (polylactic acid), ABS (acrylonitrile butadiene styrene), nylon, PETG (polyethylene terephthalate glycol), PVA (polyvinyl alcohol), PC (polycarbonate) filaments. Methods: 19 FDM 3D printing filaments which have been distributed in Korea were selected and analyzed VOCs emitted of 3D printing materials by headspace gas chromatography mass spectrometry (headspace GC-MS). Subsamples were put into a vial and heated up to 200℃ (500 rpm) during 20 minutes before analyzing FDM 3D printing filaments. Results: In the case of PLA filament, lactide and methyl methacrylate, the monomer components of one, were detected, and the volume ratio ranged 27~93%, 0.5~37% respectively. In the case of ABS filaments, styrene (50.5~59.1%), the monomer components of one, was detected. Several VOCs among acetaldehyde, toluene, ethylbenzene, xylene, etc were detected from each FDM 3D printing filaments. Conclusions: Several VOCs, semi-VOCs were emitted from FDM 3D printing filaments in this study and previous studies. Users were possibly exposed to ones so that we strongly believe that we recommend to install the ventilation system such as a local exhaust ventilation (LEV) when they operate the FDM 3D printers in a workplace.

• Fashion & Textile Research Journal
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• v.24 no.5
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• pp.505-518
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• 2022

3D printing technology, also known as additive manufacturing(AM), has not been actively used in the clothing industry despite its potential for economic, environmental, and labor efficiency. Therefore, this study aims to propose a new 3D printing method for the clothing industry, which will be more readily accessible. This roll-type printing method can print wide-sized patterns at once using a 3D modeling program and a FDM 3D printer and help overcome the limitations imposed by the size of the printer. Then, to demonstrate the practical application cases of this printing method, bags of three designs were developed. Prior to product development, a thickness test was performed for stable printing using TPU(Thermoplastic Poly Urethane) filament, and a thickness of 0.45 mm was found to be most suitable for it. Next, the time efficiency test showed that the roll-type printing method takes less time compared to the general printing method in printing wide-sized patterns. Based on these tests, three bags, , and , were developed to confirm the suitability of the roll-type printing method for product development. The advantages of 3D roll-type printing can lie in overcoming of the spatial limitation, and the environmental sustainability as it can reduce waste from the production process. This study is significant in that it presents a new 3D printing method to improve the space limitations and time inefficiency of 3D printers.

• Journal of Naturopathy
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• v.10 no.2
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• pp.71-76
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• 2021

Background: The understanding of back-pain as one of the commonest clinical presentations, made the path to the present study. More than three-quarters of the world's population experience back-pain at some time in their lives Purpose: The present study has evaluated the selected Naturopathic therapeutic procedures on individuals with low back-pain. Methods: Thirteen patients were selected for the study and randomly divided into two groups, viz., Group A, Naturopathic group and Group B, Control group. One patient discontinued. Naturopathic group was treated with mud pack, aromatherapy massage with Eucalyptus oil, acupressure, steam, wet trunk pack, exercises, relaxation and breathing exercises. Advice for life style and diet was given for patients of both the groups. The effect of the therapy was assessed subjectively and objectively. Particular scores drawn for Naturopathic group and control group were individually analyzed before and after treatment and the values were compared using standard statistical protocols. Results: Naturopathic intervention revealed 100% relief in both subjective and objective parameters (i.e., 6 out of 14 parameters showed statistically highly significant P < 0.01 results, while 8 showed significant results P < 0.05). Conclusion: Statistically highly significant results of this study point out the successful management of the multi factorial low back-pain with a multi focused Naturopathic treatment approach. Such encouraging results may pave the way for a future study on a large sample in a longer duration incorporating clinical investigations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1723-1728
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• 2021

C-ITS is an intelligent transportation system that can improve transportation convenience and traffic safety by collecting, managing, and providing traffic information between components such as vehicles, road infrastructure, drivers, and pedestrians. In Korea, road infrastructure is being built across the country through the C-ITS project, and various services such as real-time traffic information provision and bus operation management are provided. However, the current state-of-the-art road infrastructure and information linkage system are insufficient to build C-ITS. In this paper, considering the continuity of time in various spatial aspects, we proposed a group-type network-based traffic situation recognition system that can recognize traffic flows and unexpected accidents through information linkage between traffic infrastructures. It is expected that the proposed system can primarily respond to accident detection and warning in the field, and can be utilized as more diverse traffic information services through information linkage with other systems.

• Safety and Health at Work
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• v.13 no.3
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• pp.336-342
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• 2022

Background: This study aims to identify the safety and health risk perceptions toward the coronavirus disease-2019 (COVID-19) pandemic based on gender in Korean university students who work and study during the pandemic. Methods: A nationwide convenient sampling method was implemented to eliminate any regional characteristics in 757 university students, including those who studied while working. The participants answered the online questionnaire for one week. The collected data were analyzed using the R version 3.4.1 program. Results: The results comparing the safety and health risk perceptions toward COVID-19 based on the gender of the subjects who work while studying, "I often use the Internet to obtain information on COVID-19 infection control" are females appeared to use the internet more often (t = -2.18, p = 0.031) than males. "Compared to pre-COVID-19, I am currently feeling safe after the outbreak" is females felt less safe (t = 3.43, p < 0.001). Although COVID-19 infection control awareness is high among Korean university students and officials, males reported higher scores over females in all the questions, which was statistically significant. Conclusion: There should be prioritized psychological measures for prevention against COVID-19 for vulnerable groups with high mental health risks. A network must be established to protect the mental health of such groups, and candidates who require intervention must be actively identified and supported. Therefore, there must be efforts to deliver accurate information based on scientific evidence of the infectious disease, and the actions should be supported through such active communication.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3516-3525
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• 2022

The high capture cross-section (𝜎_c) of Gadolinium (Gd-155 and Gd-157) causes reactivity penalty and swing at the initial stage of fuel burnup in Pressurized Water Reactor (PWR). The present study is concerned with the feasibility of the combination of mixed burnable poison with both low and high 𝜎_c as an approach to minimize these effects. Two considered reference designs are fuel assemblies with 24 IBA rods of Gd₂O₃ and Er₂O₃ respectively. Models comprise nuclear fuel with a homogeneous mixture of Er₂O₃, AmO₂, SmO₂, and HfO₂ with Gd₂O₃ as well as the coating of PaO₂ and ZrB₂ on the Gd₂O₃ pellet's outer surface. The infinite multiplication factor was determined and reactivity was calculated considering 3% neutron leakage rate. All models except Er₂O₃ and SmO₂ showed expected results namely higher values of these parameters than the reference design of Gd₂O₃ at the early burnup period. The highest value was found for the model of PaO₂ and Gd₂O₃ followed by ZrB₂ and HfO₂. The cycle burnup, discharge burnup, and cycle length for three batch refueling were calculated using Linear Reactivity Model (LRM). The pin power distribution, energy-dependent neutron flux and Fuel Temperature Coefficient (FTC) were also studied. An optimization of model 1 was carried out to investigate effects of different isotopic compositions of Gd₂O₃ and absorber coating thickness.

• The Korea Journal of Herbology
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• v.24 no.4
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• pp.143-148
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• 2009

Objectives : Anxiety and depression are stress-related disorders. Their prevalence are increasing rapidly. Ginseng is the root of Panax ginseng C.A. Meyer (Araliaceae) which has been used for many centuries in asian region. Anxiolytic effect is one of the popular effects of ginseng. Several studies reported saponin fraction of ginseng, including ginsenoside, is a major ingredient of anxiolytic effect. In present study, we investigated anxiolytic-like and antidepressant-like effect of non-saponin fraction in mice. Material and Method : Mice were divided into five groups. Experimental groups were administered non-saponin fractions (25 mg/kg; nsp25, 50 mg/kg; nsp50, 100 mg/kg; nsp100) respectively once a day in the morning at 9am for 1 week. Then, we performed elevated plus-maze (EPM) test for investigating the anxiolytic-like effect and forced swimming test (FST) for investigating the antidepressant-like action. Results : Non-saponin fraction 50 mg/kg group increased frequency and time spent (p<0.05) in open arm on EPM test and decreased immobility time (p<0.05) on FST compared with control group. Conclusions : We suggest that non-saponin fraction has anxiolytic-like effect and antidepressant like effect in mice.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.1
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• pp.11-23
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• 2023

Purpose: This study aimed to determine the effects of cervico-thoracic (C-T) mobilization technique and therapeutic exercise on muscle activity, craniovertebral angle (CVA), and neck disability index (NDI) in patients with neck pain. Methods: : A total of 30 patients with neck pain were included and divided into C-T mobilization combined with Pilates group (Experimental group; EG) and thoracic mobilization and self-exercise (Control group; CG) group; each group consisted of 15 patients. The exercises were performed by patients in both groups three times a week, for four weeks. NDI was used to measure functional disability and sEMG was used to measure muscle activity. Results: The EG participants showed significant improvement in the CVA and NDI after the intervention than the CG (p<.05). While both groups presented after intervention decreased muscle activity(upper trapezius), there were no statistically significant differences between the groups (p>.05). Conclusion: The findings of this study suggest that thoracic mobilization technique combined with Pilates exercise may have beneficial effects on CVA and NDI in patients with neck pain and forward head posture.