• Journal of Life Science
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• v.30 no.12
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• pp.1092-1100
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• 2020

The six-transmembrane epithelial antigen of prostate 4 (Steap4) is a metalloreductase that plays a role in intracellular iron and cupper homeostasis, inflammatory response, and glucose and lipid metabolism. Previously, Steap4 has been reported to stimulate adipocyte differentiation; however, the underlying mechanisms of this action remain unexplored. In the present study, we investigated the molecular mechanisms involved in Steap4-induced adipocyte differentiation using 3T3-L1 cells, immortalized brown adipocyte (iBA) cells, and mouse embryonic fibroblast C3H10T1/2 cells. The knockdown of Steap4 using adenovirus-containing shRNA attenuated mitotic clonal expansion (MCE), as evidenced by the impaired proliferation of 3T3-L1 cells, iBA cells, and C3H10T1/2 cells within 48 hr after adding the differentiation medium. Steap4 knockdown downregulated G1/S phase transition-related cell cycle regulators (including cyclin A and cyclin D) and upregulated cell cycle inhibitors (including p21 and p27). Furthermore, Steap4 knockdown inhibited the phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase, and Akt. Moreover, Steap4 knockdown repressed the expression of early adipogenic activators, such as CCAAT-enhancer-binding protein β (C/EBPβ) and Kruppel-like factor family factor 4 (KLF4). On the other hand, Steap4 knockdown stimulated the expression of adipogenic inhibitors, including KLF2, KLF3, and GATA2. The overexpression of Steap4 using an adenovirus removed the repressive histone marks H3K9me2 and H3K9me3 on the promoter of C/EBPβ. These results indicate that Stepa4 stimulates adipocyte differentiation through the induction of MCE and the modulation of early adipogenic transcription factors, including C/EBPβ, during the early phase of adipocyte differentiation.

• Journal of Nutrition and Health
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• v.54 no.2
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• pp.179-198
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• 2021

Purpose: This study examined general characteristics, health status, accessibility to medical services, health-related quality of life, dietary behavior, and energy and nutrient intakes of the elderly at different levels of food security utilizing data from the 7th Korea National Health and Nutrition Examination Survey (2016-2018). Methods: The elderly subjects (1,721 males and 2,271 females) were divided into 3 groups (secure, mildly insecure, moderately/severely insecure) according to their food security levels. Health and nutrient status was determined using energy intake, nutrient density, the prevalence of insufficient nutrient intake, dietary behavior, and health status. Results: The elderly with food insecurities had a lower self-evaluated health status and a higher prevalence of physician-diagnosed chronic diseases such as arthritis, osteoarthritis, rheumatoid arthritis, osteoporosis for males, and hypertension, stroke, arthritis, and osteoarthritis for females. The associated financial burden was the major reason for not accessing medical services in the food insecure group. Furthermore, the food insecure group had a higher risk of impaired health-related quality of life compared to the secure group. The proportion of subjects with an energy intake below the estimated energy requirement was higher in the food insecure group and a significantly higher prevalence of insufficient intake was observed for all the nutrients (proteins, vitamin A, vitamin B₁, vitamin B₂, niacin, vitamin C, calcium, and iron) assessed in this study compared to the food secure group. Conclusion: This study suggests that food insecurity poses a challenge to the health and nutritional status of the elderly population in Korea and needs proper management. It would be helpful to develop food and nutrition assistance programs to ensure the food stability of the elderly population and assure quality to address gaps in their nutrient intake.

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.189-197
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• 2022

Asthma is a chronic inflammatory disease characterized by recurring symptoms, airflow obstruction, and bronchial hyper-responsiveness. The onset of asthma for most patients begins early in life, and current asthma treatment with anti-inflammatory agents can have adverse effects, eventually leading to impaired quality of life. In the pathogenesis of asthma, macrophages and basophils play a vital role during progression. Macrophages not only induce inflammation by secreting inflammatory cytokines but also promote DNA damage and mucus production through nitric oxide (NO) production. Basophils enhance eosinophil recruitment and aggravate asthma through the FcεRIα receptor with high affinity for histamine and IgE. Therefore, in this study, we investigated whether the activation of macrophages and basophils is suppressed by the individual extracts of 28 natural products. RAW 264.7 cells (mouse macrophages) were treated with the natural products in LPS, and 4 natural product extracts resulted in decreased NO production. In β-hexosaminidase assay using RBL-2H3 cells (rat basophils), 19 natural product extracts decreased β-hexosaminidase production. In NO production and β-hexosaminidase assay using macrophages and basophils, 3 natural product extracts (Plantago asiatica, Centella asiatica, and Perilla frutescens var. japonica) significantly inhibited NO production and β-hexosaminidase release. Overall, we examined the inhibitory effects of 28 natural product extracts on macrophage and basophil activity, and the findings demonstrated the potential of natural product extracts for treating asthma and macrophage- and basophil-related diseases.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.1
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• pp.87-96
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• 2023

This study was conducted to discover substances that regulate skin surface acidification using human epidermal keratinocyte cell lines, and to investigate their effects on the moisturizing ability and skin barrier function of the stratum corneum. Prunella vulgaris (P. vulgaris) is an herb widely distributed in Northwest Africa and North America that has been studied for its anti-apoptotic, antioxidant, and anti-inflammatory effects. However, research on the regulation of NHE1 expression and the restoration of skin barrier function has not been conducted. Analysis of P. vulgaris revealed the presence of rosmarinic acid and caffeic acid as active ingredients, which were tested for toxicity in human epidermal keratinocyte cell lines (HaCaT), and showed no toxic effects were observed at high concentarion (100 ㎍/mL or 100 µM). It is known that sodium-hydrogen ion exchange pumps (NHE1) decrease in expression in aging skin to maintain the acidic pH of the stratum corneum, and it is hypothesized that this decrease plays an important role in the impaired restoration of skin barrier function in aging skin. P. vulgaris extract and caffeic acid increased the expression of NHE1 in keratinocytes, increased the expression of natural moisturizing factor (NMF) precursor filaggrin and ceramide synthesis enzyme serine palmitoyl transferase (SPT). In addition, P. vulgaris and caffeic acid decreased the extracellular pH of keratinocytes, indicating a direct effect on skin pH regulation. Taken together, these results suggest that P. vulgaris and caffeic acid can regulate skin pH through NHE1 modulation, and may help to restore skin barrier function by increasing NMF and ceramide synthesis. These results show the possibility that honeysuckle and caffeic acid can have a positive effect on skin health, and can be the basis for the development of new skin protection products using them.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4C
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• pp.247-254
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• 2006

Online testing method is one of the numerical experiment methods using experimental information for a numerical analysis directly. The method has an advantage in that analysis can be conducted without using an idealized mechanical model, because mechanical properties are updated from element test for a numerical analysis in real time. The online testing method has mainly been used for the geotechnical seismic engineering, whose major target is sand. A testing method that may be applied to a consolidation problem has recently been developed and laboratory and field verifications have been tried. Although related research thus far has mainly used a method to update average reaction for a numerical analysis by positioning an element tests at the center of a consolidation layer, a weakness that accuracy of the analysis can be impaired as the thickness of the consolidation layer becomes more thicker has been pointed out regarding the method. To clarify the effectiveness and possible analysis scope of the online testing method in relation to the consolidation problem, we need to review the results by applying experiment conditions that may completely exclude such a factor. This research reviewed the results of the online consolidation test in terms of reproduction of the consolidation settlement and the dissipation of excess pore water pressure of a clay specimen by comparing the results of an online consolidation test and a separated-type consolidation test carried out under the same conditions. As a result, the online consolidation test reproduced the change of compressibility according effective stress of clay without a huge contradiction. In terms of the dissipation rate of excess pore water pressure, however, the online consolidation test was a little faster. In conclusion, experiment procedure needs to improve in a direction that hydraulic conductivity can be updated in real time so as to more precisely predict the dissipation of excess pore water pressure. Further research or improvement should be carried out with regard to the consolidation settlement after the end of the dissipation of excess pore water pressure.

• Journal of Korea Entertainment Industry Association
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• v.13 no.3
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• pp.181-192
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• 2019

The purpose of this study is to look at the fun that high school students from blind schools feel in sports programs. A questionnaire was used to collect data from 10 out of 12 blind schools nationwide, including 122 male and 102 female students. Research tools are open questionnaires and questions are as follows. - Questionnaire: "Write down three of the most interesting things about sports programs." The data analysis was done with frequency analysis and the following conclusions were drawn. First, male high school students at blind schools are able to build up their physical strength in the area of competent factors (control-self) (23, 21.5%), in the area of competent factors (7, 77.8%) and in the area of motion-related factors (competition) (24, 15.1%), and in the area of non-execution factors (26, 37.7%), Second, high school girls with visual impairments did not respond in the areas of proficiency (control-self) because of stress release (25, 26.6%), in the areas of control-tain), in the areas of movement (competition) because they were able to do various exercises (22, 15.7%), and in the areas of non-watering (environmental) (18, 37.5%). Third, in the sports program comparative analysis of high school students between genders of blind schools, boys are interested in health and physical fitness in the field of competent factors (control-self) and girls are considered to be a means of relieving stress. In the field of competent factors (control-others), boys and girls can react to a variety of sports opportunities. In the future, by studying the fun of students in the physical education program through research to find out more fun in the school physical education program, we will explore practical ways to maximize student participation and increase motivation level The educational aspect of the process, that is, the educational value provided by the physical education, should be composed of content that can change the thinking and behavior of the teacher and the student so that the program contents and operation method.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.767-773
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• 2023

To In this study, we sought to evaluate related factors affecting lung volume and their significance in pulmonary function and ventilation disorders. As experimental subjects, 206 normal adult men and women who underwent a low-dose chest CT scan and a spirometry test were selected at the same time. The experimental method was to measure lung volume using lung CT images obtained through a low-dose chest CT scan using deep learning-based AVIEW. Measurements were made using the LCS automatic diagnosis program. In addition, the results of measuring lung function were obtained using a spirometer, and gender and BMI were selected as related factors that affect lung volume, and significance was evaluated through an independent sample T-test with lung volume. As a result of the experiment, it was confirmed that in evaluating lung volume according to gender, all lung volumes of men were larger than all lung volumes of women. he result of an independent samples T-test using the respective average values for gender and lung volume showed that all lung volumes were larger in men than in women, which was significant (p<0.001). And in the evaluation of lung volume according to BMI index, it was confirmed that all lung volumes of adults with a BMI index of 24 or higher were larger than all lung volumes of adults with a BMI index of less than 24. However, the independent samples T-test using the respective average values for BMI index and lung volume did not show a significant result that all lung volumes were larger in BMI index 24 or higher than in BMI index less than 24 (p<0.055). In the evaluation of lung volume according to the presence or absence of pulmonary ventilation impairment, it was confirmed that all lung volumes of adults with normal pulmonary function ventilation were larger than all lung volumes of adults with pulmonary ventilation impairment. And as a result of the independent sample T-test using the respective average values for the presence or absence of pulmonary ventilation disorder and lung volume, the result was significant that all lung volumes were larger in adults with normal pulmonary function ventilation than in adults with pulmonary function ventilation disorder (p <0.001). Lung volume and spirometry test results are the most important indicators in evaluating lung health, and using these two indicators together to evaluate lung function is the most accurate evaluation method. Therefore, it is expected that this study will be used as basic data by presenting the average lung volume for adults with normal ventilation and adults with impaired lung function and ventilation in similar future studies on lung volume and vital capacity testing.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.3
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• pp.155-172
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• 2024

The COVID-19 pandemic not only posed an enormous human crisis, but also had a profound impact on firms' survival. Social distancing and global lockdown measures designed to protect human lives have paradoxically impaired the business environment. As a result, firms that sought to gain competitive advantage by leveraging external resources were cut off from the external world and faced unexpected challenges. Under these circumstances, researches were conducted in the early stage of the pandemic to explore how certain firms survived while others fell, but they were limited to re-examining business performance using traditional financial factors. However, this study aims to investigate the role of entrepreneurs' competency in crisis situations from the Resource-Based View (RBV), as such competency plays an important role in improving business performance and subsequently the probability of startups' survival. Specifically, we evaluated the performance as of end of 2019 of 1,127 startups evaluated by the Korea Technology Finance Corporation (KOTEC), which provides policy financing based on technology assessment, in 2016. We then conducted an empirical study to determine the mediating role of business performance in the relationship between entrepreneurial competencies and firm survival by verifying how many of the sample firms were still in operation at the end of June 2023, when the Korean government declared COVID-19 as an endemic. For this purpose, we defined technological, financial, and marketing competencies as the sub-factors of entrepreneurial competency, and sales growth rate and employment growth rate as the sub-factors of business performance. The results of the empirical analysis showed that technological and financial competencies of the entrepreneur had a positive impact on both business performance and firm survival, and that sales growth rate and employment growth rate mediated the relationship between technological competence and firm survival. However, the positive influence of entrepreneurs' financial competence of the survival of startups was only evident through the growth of employment. This study is the first study in South Korea to define the survival factors of startups in the context of the COVID-19 pandemic, and is expected to contribute to the theoretical and practical discussions on the importance of entrepreneurs' competency as a firms' survival factor based on RVB.

• Journal of Nutrition and Health
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• v.42 no.5
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• pp.423-433
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• 2009

Folate and vitamin $B_{12}$ are essential cofactors for homocysteine (Hcy) metabolism. Homocysteinemia has been related with cardiovascular and neurodegenerative disease. We examined the effect of folate and/or vitamin $B_{12}$ deficiency on biomarkers of one carbon metabolism in blood, liver and brain, and analyzed the correlation between vitamin biomarkers in mild and moderate homocysteinemia. In this study, Sprague-Dawley male rats (5 groups, n = 10) were fed folatesufficient diet (FS), folate-deficient diet (FD) with 0 or 3 g homocystine (FSH and FDH), and folate-/vitamin $B_{12}$-deficient diet with 3 g homocystine (FDHCD) for 8 weeks. The FDH diet induced mild homocysteinemia (plasma Hcy 17.41 ${\pm}$ 1.94 nmol/mL) and the FDHCD diet induced moderate homocysteinemia (plasma Hcy 44.13 ${\pm}$ 2.65 nmol/mL), respectively. Although liver and brain folate levels were significantly lower compared with those values of rats fed FS or FSH (p < 0.001, p < 0.01 respectively), there were no significant differences in folate levels in liver and brain among the rats fed FD, FDH and FDHCD diet. However, rats fed FDHCD showed higher plasma folate levels (126.5 ${\pm}$ 9.6 nmol/L) compared with rats fed FD and FDH (21.1 ${\pm}$ 1.4 nmol/L, 22.0 ${\pm}$ 2.2 nmol/L)(p < 0.001), which is the feature of "ethyl-folate trap"by vitamin $B_{12}$ deficiency. Plasma Hcy was correlated with hepatic folate (r = -0.641, p < 0.01) but not with plasma folate or brain folate in this experimental condition. However, as we eliminated FDHCD group during correlation test, plasma Hcy was correlated with plasma folate (r = -0.581, p < 0.01), hepatic folate (r = -0.684, p < 0.01) and brain folate (r = -0.321, p < 0.05). Hepatic S-adenosylmethionine (SAM) level was lower in rats fed FD, FDH and FDHCD than in rats fed FS and FSH (p < 0.001, p < 0.001 respectively) and hepatic S-adenosylhomocysteine (SAH) level was significantly higher in those groups. The SAH level in brain was also significantly increased in rats fed FDHCD (p < 0.05). However, brain SAM level was not affected by folate and/or vitamin $B_{12}$ deficiency. This result suggests that dietary folate- and vitamin B12-deficiency may inhibit methylation in brain by increasing SAH rather than decreasing SAM level, which may be closely associated with impaired cognitive function in nutritional homocysteinemia.

• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.669-685
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• 1997

Previous studies, reporting the inverse relationship between osteoarthritis and osteoporosis suggest the existence of possible pathophysiologic mechanisms between them. To examinine the hypothesis that 'bone mineral densities of women with osteoarthritis are significantly higher than that of women without osteoarthritis in Korea', subjects from the health and nutritional examination survey in Kuri city were sampled. Samples were selected through multi-stage sampling frame using established clusters in Kuri city. From August 18 to September 10,1997, the survey was conducted. Among the. total number of selected sample population (1,656 people), response .ate was 52.4 percent (348 men and 519 women). 420 women who took BMD measurement, radiologic exam, and anthropometric exam were selected for the analysis. The analytic results are as follows. 1. General characteristics: Mean BMD was $0.493g/cm^2$, mean age was 43.0, mean BMI was $23.9kg/m^2$. The number of women who experienced menopause was 106, hysterectomy was 19. There were 0 case of osteoarthritis of hip, 64 cases of osteoarthritis of knee, and 2 cases of osteoarthritis of hand. 2. Univariate analysis results: Mean BMD of women with the osteoarthritis of knee was significantly lower than that of women without the osteoarthritis of knee(0.4269 vs. $0.5057g/cm^2$). But, there were too few cases of osteoarthritis of hip and hand, so comparative studies of BMD in osteoarthritis of hip and hand could not be conducted. There were significant differences of BMD among pre-menopause group(0.5204), post-menopause group(0.4206), and hysterectomy group(0.4881). Additionally, there were significant differences of BMD among diabetes group(0.4297), impaired glucose tolerance group(0.4874), and normal group(0.5057). Furthermore, age, parity, BMI, bioimpedance were significantly related with BMD. 3. Multivariate analysis results: To examinine the relationship between osteoarthritis and BMD while controlling the other variables' effects which were significant in the univariate analyses, multiple linear regression analysis was done. But, it was found that osteoarthritis of knee was not a significant variable to BMD anymore. While age and menopause had significant negative relationship with BMD. Diabetes, parity, BMI, and bioimpedance did not have significant relationships with BMD. After stratification of subjects according to menopause, multiple linear regression analyses were done to each strata. Consequently, age in post-menopause group, age and osteoarthritis of knee in hysterectomy group showed significant negative relationship with BMD. The results did not support the many results of other previous studies done with white men and women. further studies of biological plausibility to Korean women are recommended. Also it is suggested that longitudinal study to verify the relationship between osteoarthritis and BMD will be valuable.