• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.415-424
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• 2021

The life of studying abroad includes not only school life, but also various areas such as economy, social relationship, and culture, so the level of satisfaction in each area could be differently shown in each individual. Based on this critical mind, this study aims to analyze the satisfaction with life of studying abroad in the multidimensional perspective. To analyze this, a latent class analysis was applied to identify subgroups, and a multinomial logistic regression model was applied to verify factors influencing group classification. The results of the analysis could be summarized into two. First, there were sub-groups showing different satisfaction with life of studying abroad. The sub-groups showed different levels of satisfaction in five areas such as housing, economy, social relationship, study, and culture, which were not discerned in single dimension. Second, the classification of group was complexly influenced by academic factor, psychological/emotional factor, and environmental factor. Especially, the predictive factor had different influences on each sub-factor. Based on such results of this study, this study aims to seek for the practical and policy-level suggestions for improving foreign students' satisfaction with life of studying abroad.

• Journal of Korean Library and Information Science Society
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• v.52 no.2
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• pp.127-144
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• 2021

The purpose of this study is to redefine the competencies of teacher librarians and to derive implications for training and re-educating teacher librarians by analyzing the priorities of competencies. A questionnaire survey targeting teacher librarians based on analytic hierarchy process has been conducted. The results indicate that in terms of the upper-level areas of competencies, it was found that they prioritized teacher librarians' competencies in the following order: information specialists, teachers, administrators, and cooperative leaders. Analysis of the lower levels of competency indicates that the priorities of the required competencies are listed in the following order: collection development, management and preservation, teaching and learning, media production, information service, library cooperative instruction, library assisted instruction, content curation. Therefore, being able to provide information resources by developing a collection of books to support the educational process in school libraries was found to be a critical competency. It seems necessary to cultivate the capacity to manage online and offline collections and produce and provide various teaching media and services by utilizing school library resources. It seems to give implications for the education of teacher librarians.

• Journal of Environmental Science International
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• v.30 no.12
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• pp.1067-1079
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• 2021

The coastal water is a space where salmon (Oncorhynchus keta), critical energy-conveying mediator, stay to adapt to different environments while traveling between ocean and river ecosystems for spawning and growth. The mid-eastern coast of Korea (MECW) is the southern limit of salmon distributed in the North Pacific Ocean. Understanding the distribution and migration characteristics of salmon in the MECW is important for the prediction of changes in the amount and distribution of salmon related to changes in the future marine environment. We analyzed the relationship between the salmon migratory timing ascending the Wangpi river and change in vertical seawater temperature and tidal elevation. Overall results highlight that (1) Salmon began to ascend the river when the sea surface water temperature (SST) decreased below 20℃; (2) The number of salmon ascending the river increased when the temperature difference between the upper and lower layers decreased, but decreased when the temperature difference was higher than 5℃; (3) The number of salmon ascending the river peaked, when the SST was 18℃-19℃ and sea levels rose at high tide. This study provide important insight into predicting changes in the ecosystem energy circulation through climate change at its southern distribution limit.

• Tuberculosis and Respiratory Diseases
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• v.85 no.2
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• pp.137-146
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• 2022

Background: Farinelli breathing (FB) exercise is a typical breathing exercise used by singers. This study aimed to compare effects of FB exercise and diaphragmatic breathing (DB) exercise on respiratory function and symptoms in patients with chronic obstructive pulmonary disease (COPD). Methods: Sixteen patients aged 51-80 years with mild or moderate COPD were recruited for this study. They were divided into two groups: DB group (n=8) and FB group (n=8). Both groups received complete breathing exercise training five times per week for 8 weeks. Their respiratory functions, COPD symptoms, cytokine levels, and oxidative stress variables were analyzed during pre- and post-tests. Dependent variables were compared between pre- and post-tests using paired t-tests. An independent t-test was used to compare variables between the groups. Differences were considered significant at p<0.05. Results: The maximal expiratory pressure (MEP), maximum oxygen consumption (VO₂max), and COPD Assessment Test (CAT) scores changed significantly in the DB group after the 8-week intervention compared to those at pre-test, whereas force vital capacity, forced expiratory volume in the first second, maximum voluntary ventilation, maximal inspiratory pressure (MIP), MEP, VO₂max, CAT score, tumor necrosis factor-α, and malondialdehyde level changed significantly in the FB group at post-test compared to those at pre-test. Moreover, both MIP and MEP in the FB group were significantly higher than those in the DB group. Conclusion: FB exercise improved respiratory functions and COPD symptoms of patients with COPD. It might be an alternative breathing exercise in pulmonary rehabilitation programs for patients with COPD.

• Molecules and Cells
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• v.45 no.7
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• pp.454-464
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• 2022

DJ-1 is one of the causative genes of early-onset familial Parkinson's disease (PD). As a result, DJ-1 influences the pathogenesis of sporadic PD. DJ-1 has various physiological functions that converge to control the levels of intracellular reactive oxygen species (ROS). Based on genetic analyses that sought to investigate novel antioxidant DJ-1 downstream genes, pyruvate dehydrogenase (PDH) kinase (PDK) was demonstrated to increase survival rates and decrease dopaminergic (DA) neuron loss in DJ-1 mutant flies under oxidative stress. PDK phosphorylates and inhibits the PDH complex (PDC), subsequently downregulating glucose metabolism in the mitochondria, which is a major source of intracellular ROS. A loss-of-function mutation in PDK was not found to have a significant effect on fly development and reproduction, but severely ameliorated oxidative stress resistance. Thus, PDK plays a critical role in the protection against oxidative stress. Loss of PDH phosphatase (PDP), which dephosphorylates and activates PDH, was also shown to protect DJ-1 mutants from oxidative stress, ultimately supporting our findings. Further genetic analyses suggested that DJ-1 controls PDK expression through hypoxia-inducible factor 1 (HIF-1), a transcriptional regulator of the adaptive response to hypoxia and oxidative stress. Furthermore, CPI-613, an inhibitor of PDH, protected DJ-1 null flies from oxidative stress, suggesting that the genetic and pharmacological inhibition of PDH may be a novel treatment strategy for PD associated with DJ-1 dysfunction.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.307-313
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• 2022

In this study, the correlation between Half Cell Potential(HCP) and the corrosion influencing factors was analyzed with considering three levels of water-cement ratio, the concentration of chloride solution, and cover depth. As a result of long-term corrosion monitoring, HCP behavior was close to the critical corrosion potential(-350 mV) in all water-cement ratios in the case of 3.5 % and 7.0 % chloride concentration. Regarding the passed charge test in 548 curing days, the passed charge results were improved to 'Moderate' grade. Multiple regression analysis was performed to evaluate the correlation between corrosion influencing factors and HCP, and it was evaluated that the effects of influencing factors to HCP were in the order of chloride concentration, water-cement ratio, and cover depth. In the case of the relationship between HCP and the passed charge, the coefficient of determination showed a high level of 0.9, which yielded a close correlation between the passed charge and HCP.

• BMB Reports
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• v.55 no.11
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• pp.571-576
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• 2022

Advancements in the field of proteomics have provided opportunities to develop diagnostic and therapeutic strategies against various diseases. About half of the world's population remains at risk of malaria. Caused by protozoan parasites of the genus Plasmodium, malaria is one of the oldest and largest risk factors responsible for the global burden of infectious diseases with an estimated 3.2 billion persons at risk of infection. For epidemiological surveillance and appropriate treatment of individuals infected with Plasmodium spp., timely detection is critical. In this study, we used combinations of depletion of abundant plasma proteins, 2-dimensional gel electrophoresis (2-DE), image analysis, LC-MS/MS and western blot analysis on the plasma of healthy donors (100 individuals) and vivax and falciparum malaria patients (100 vivax malaria patients and 8 falciparum malaria patients). These analyses revealed that α1-antichymotrypsin (AACT) protein levels were elevated in vivax malaria patient plasma samples (mean fold-change ± standard error: 2.83 ± 0.11, based on band intensities), but not in plasma from patients with other mosquito-borne infectious diseases. The results of AACT immunoblot analyses showed that AACT protein was significantly elevated in vivax and falciparum malaria patient plasma samples (≥ 2-fold) compared to healthy control donor plasma samples, which has not been previously reported.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1245-1252
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• 2022

Induced pluripotent stem cells (iPSCs) can be generated from somatic cells using Oct4, Sox2, Klf4, and c-Myc (OSKM). Small molecules can enhance reprogramming. Licochalcone D (LCD), a flavonoid compound present mainly in the roots of Glycyrrhiza inflata, acts on known signaling pathways involved in transcriptional activity and signal transduction, including the PGC1-α and MAPK families. In this study, we demonstrated that LCD improved reprogramming efficiency. LCD-treated iPSCs (LCD-iPSCs) expressed pluripotency-related genes Oct4, Sox2, Nanog, and Prdm14. Moreover, LCD-iPSCs differentiated into all three germ layers in vitro and formed chimeras. The mesenchymal-to-epithelial transition (MET) is critical for somatic cell reprogramming. We found that the expression levels of mesenchymal genes (Snail2 and Twist) decreased and those of epithelial genes (DSP, Cldn3, Crb3, and Ocln) dramatically increased in OR-MEF (OG2^+/+/ROSA26^+/+) cells treated with LCD for 3 days, indicating that MET effectively occurred in LCD-treated OR-MEF cells. Thus, LCD enhanced the generation of iPSCs from somatic cells by promoting MET at the early stages of reprogramming.

• Korean Journal of Biological Psychiatry
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• v.29 no.2
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• pp.46-55
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• 2022

Objectives Many studies have reported noticeable increases in the proportion of employees working either relatively short or relatively long hours. Such trends have been accompanied by an increasing concern that how much subjective mental well-being of employees would be influenced by their hours of work. The aim of this study was to investigate the association between work hours and clinically relevant depressive symptoms with demographic variables adjusted. Methods Participants were employees of a total of 56 private companies and local government organizations in Korea, aged 19 to 65 years. A self-report questionnaire that included items on working hour, job stress, levels of depression, and socio-demographic factors was administered to 15360 Korean employees, with 14477 valid responses. Hierarchical linear regression analyses, adjusted for sociodemographic factors, job related demographic factors, job stress, were used additionally to estimate the association between working hours and depressive scores. Results We found that working more than 40 hours per week correlated positively with the level of depressive symptoms after adjusting for demographic variables and the level of job stress. Furthermore, working 40 or fewer hours per week correlated negatively with the level of depressive symptoms. Being younger (β = -0.078, β = -0.099), being a female (β = 2.770, β = 1.268), and possessing a lower level of education (β = -0.315, β = -1.125) were significantly associated with higher level of depressive symptoms in all respondents. Conclusions Both of working excessively long or short hours is significantly associated with the prevalence of depressive symptoms. Establishing proper office hours for employees is critical to improving the quality of working conditions and maintaining good mental health in the workplace.

• Journal of Veterinary Science
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• v.21 no.3
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• pp.50.1-50.16
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• 2020

Background: Porcine parvovirus (PPV) is a single-stranded DNA virus that causes porcine reproductive failure. It is of critical importance to study PPV pathogenesis for the prevention and control of the disease. NS1, a PPV non-structural protein, is participated in viral DNA replication, transcriptional regulation, and cytotoxicity. Our previous research showed that PPV can activate nuclear factor kappa B (NF-κB) signaling pathway and then up-regulate the expression of interleukin (IL)-6. Objectives: Herein, the purpose of this study is to determine whether the non-structural protein NS1 of PPV also has the same function. Methods: Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay, western blot, immunofluorescence assay and small interfering RNA (siRNA) were used. Results: Our findings demonstrated that PPV NS1 protein can up-regulate the expression levels of IL-6 and tumor necrosis factor-alpha in a dose-dependent manner. Moreover, PPV NS1 protein was found to induce the phosphorylation of IκBα, then leading to the phosphorylation and nuclear translocation of NF-κB. In addition, the NS1 protein activated the upstream pathways of NF-κB. Meanwhile, TLR2-siRNA assay showed TLR2 plays an important role in the activation of NF-κB signaling pathway induced by PPV-NS1. Conclusions: These findings indicated that PPV NS1 protein induced the up-regulated of IL-6 expression through activating the TLR2 and NF-κB signaling pathways. In conclusion, these findings provide a new avenue to study the innate immune mechanism of PPV infection.