• Membrane Journal
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• v.29 no.5
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• pp.263-275
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• 2019

In the present study, thickness of MOR zeolite membranes was controlled by changing seed size, seeding amount, and aging time of hydrothermal solution, and then effect of membrane thickness on pervaporative ethanol dehydration for 90 wt.% ethanol-water mixture was investigated. First, nanosize MOR zeolite seeds with a diameter of 20 to 30 nm was successfully prepared by planetary milling a laboratory synthesized MOR zeolites and the coating amount was controlled by seed concentration and infiltration volume of coating solution during vacuum-assisted seeding. As seeding amount decreased, membrane thickness was reduced up to around $4{\mu}m$. The MOR zeolite membrane having a thickness of $4{\mu}m$ showed a water/ethanol separation factor of 760 and water flux of $1.0kg/m^2h$. The excellent water flux was due to the reduced membrane thickness which was derived from the nanosize seed. Therefore, it could be concluded that membrane thickness control by using nanosize seed can be a crucial factor to improve pervaporative water flux of MOR zeolite membrane.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.326-335
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• 2021

This study was undertaken to determine the effect of fermented soybean extract and its fractions on skin cell proliferation and growth. The extract was procured by the pepsin and Lactobacillus rhamnosus fermentation of soybean. LC-MS analysis was performed subsequent to soybean fermentation, and cell viability was measured by the WST-1 assay. Cell proliferation was observed to increase after exposing cells to the fermented soybean extract and its fractions at all concentrations tested (0~2,000 ㎍/mL). In particular, compared to the normal control group and 120 % proliferation of the EGF (epidermal growth factor) positive control group, 160~180 % cell proliferation was achieved at 800 ㎍/ml, indicating the excellent potential as an application material for skin aging inhibition and skin cell regeneration. In addition, we also examined the effects of fermented soybean extract and its fractions on wound healing ability, in HaCaT cells and fibroblasts. Our results indicate excellent cell migration abilities after treatment with fermented soybean extract and its fractions, as compared to the control treatment. Similar cell migration abilities were observed in the positive control group (EGF). Taken together, our results indicate that fermented soybean extract and its fractions (F4 and F5) exert amelioratory effects as a natural material for skin.

• 한국노년학
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• v.37 no.3
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• pp.601-616
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• 2017

Elderly suicide is a major public health issue in South Korea. The aim of this study was to systematically examine the current knowledge about suicidal ideation among Korean older adults with specific focus on risk and preventive factors. In order to achieve this aim, a meta-analysis was conducted using Korean academic peer-reviewed journals published since 2001. A total of 97 articles were selected that met the research criteria (e.g., original study findings and key words of suicidal ideation, suicidal thought, and suicide). Three domains were identified and used for further analysis: individual, family, and society. Results showed that among individual factors, depression and burden or stress increased the risk of suicidal ideation, while better mental health reduced the risk of suicidal ideation. Among family factors, living alone was a risk factor for suicidal ideation, while family cohesion was a preventive factor for suicidal ideation. Among social factors, elderly discrimination, social isolation, and negative relationships were significant risk factors, while social support, social environment, and social activities were significant preventive factors affecting suicidal ideation. The results suggest several practical implications for developing suicide prevention programs and counseling approaches to address suicidal ideation. For example, depression and stress can be reduced by MBSR (Mindfulness-Based Stress Reduction) program where meditation is used as a coping strategy. In addition, counseling programs specifically focused on improving family and social relations should be implemented. Government should continuously support for these programs to prevent suicide among older Koreans.

• The Korea Journal of Herbology
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• v.29 no.2
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• pp.39-45
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• 2014

Objectives : The purpose of this study was to investigate antiaging and antioxidant effects on cultured human skin fibroblast with 80% ethanol extracts of plants including of stem of Dendropanax morbifera, Corni fructus and Lycii Fructus. Methods : An ethanol extract of three medicinal plants including stem of Dendropanax morbifera, Corni fructus and Lycii Fructus. Extracts were assessed to determine the mechanism of antioxidant and antiaging activities. Antioxidant activity of extract was evaluated by two different assays as 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and super oxide dismutase (SOD) like activities. These extracts were tested for cell viability on HS68 skin fibroblast by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. We investigated the effects of Ultraviolet-B irradiation on cytotoxicity, type 1 collagen, elastin level and oxidative damage in cultured human skin fibroblast (HS68). Recently, many studies have reported that elastin is also involved in inhibiting or repairing wrinkle formation, although collagen is a major factor in the skin wrinkle formation. Results : The extracts obtained dose-dependently increased the scavenging activity on DPPH radical scavenging activity and SOD like activity. The extracts of complex herbal medicine showed low cytotoxicity as more than 100% cell viability in 100ppm/ml concentration. HS68 fibroblasts were survived 70% at 120 $mJ/cm^2$ UVB irradiation and treated tumor necrosis factor (TNF)-alpha. The levels of aging factors and cytotoxicity were decreased by ethanol extract of complex herbal medicine. Conclusions : These results suggest that ethanol extracts of complex medicinal plants of including of stem of Dendropanax morbifera, Corni fructus and Lycii Fructus may have value as the potential antioxidant and antiaging medicinal plant.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.159-167
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• 2023

Titanium dioxide (TiO₂) is commonly used in sunscreen formulations to protect the skin surface and prevent the penetration of harmful ultraviolet (UV) rays by the physical scattering action of light. However, a disadvantage of using TiO₂ is that it can cause white turbidity when used on skin due to its inactive mineral ingredient. In addition, when TiO₂ particles are reduced to nanosize to eliminate opacity, they can increase the transmittance of visible light and reduce whitening, but may lead to serious skin problems, such as allergic inflammation. To overcome these issues, the bandgap of TiO₂ was controlled by adjusting the amount of oxygen defect and nitrogen amount, resulting in color TiO₂ tailored to the skin. This innovative technology can reduce the whitening phenomenon and effectively block blue light, which is known to cause skin aging by inducing active oxygen. The bandgap controlled TiO₂ compounds proposed in this study are hypoallergenic, broad-spectrum, and environmentally friendly. Furthermore, these compounds have been shown to significantly enhance sun protection factor (SPF) of sunscreens, demonstrating their compatibility with blue light blocking products.

• 한국노년학
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• v.29 no.2
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• pp.657-667
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• 2009

The aim of the present study was to investigate the effects of swimming exercise on growth-related telomere length and expression of TRF 2 in different tissues of SD rats. The telomere lengths of all the tissues analyzed were longer in the standard group than either in aged-control group or in two aged-exercise groups, suggesting growth-induced attrition of telomere lengths. On the other hand, it was also found that swimming exercise could attenuate this growth-related telomere attrition in the heart tissue of the long-term group only, with no significant attenuating effects of aerobic exercise on either liver telomere length or soleus muscle telomere length. Also, in the heart, TRF 2 expression was significantly lower in control group compare to standard group. But, there was significantly higher in long term exercise group compare to control group. There was positive correlation between telomere length and expression of TRF 2 in heart tissue. This study implies that the swimming exercise performed for longer periods of time can contribute to growth process of heart by regulation of telomere length and TRF 2 expression. In the growth process, the regular swimming exercise will provide a meaningful advantage for various physiological processes.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.81-105
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• 2010

This study is aimed to investigate the effects of stress on suicidal impulse, considering the mediating effects of existent spirituality, family support, and depression. The data, collected from 1,000 adults were examined by the statistics software SPSS 17.0 and AMOS 17.0, in which descriptive statistics, structural equation model analysis, and multi-group simultaneous analysis are utilized. The study shows that, from the structural equation modeling, the stress has positive effects on depression and suicidal impulses, but negative effects on existent spirituality. Existent spirituality acts as a protective factor, negatively affecting the suicidal impulse. Depression has positive effects on suicidal impulse. Therefore, existent spirituality and depression have mediational effects on the relationship between stress and suicidal impulse. The results of multi-group simultaneous analysis imply that there are no age and sex differences. In conclusion, social workers need to make great efforts to exterminate stress, and treat depression at the first priority, because the depression is a major sign of suicide. As a protective factor, strengthening existent spirituality is a very effective way to prevent a suicidal impulse.

• Land and Housing Review
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• v.14 no.4
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• pp.47-62
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• 2023

Using the dynamic panel model, this study investigates rent determinants for small and medium-sized office buildings in Korea's CBD and Gangnam areas, key business districts. The results reveal that rents for small and medium-sized office buildings in CBD and Gangnam areas are influenced by macroeconomic fluctuations and characteristics of buildings and locations, suggesting a market with both spatial consumer and investment goods attributes. There are several investment implications as follows. First, even if the location in the CBD area is advantageous, the practical limitations in renovating aging small and medium-sized office buildings must be taken into account when investing. Second, parking conditions are a key factor influencing rent prices in CBD areas, so evaluating the parking facilities and improvement potential of small and medium-sized office buildings is essential for investors. Finally, due to the high sensitivity of Gangnam's small and medium-sized office market to macroeconomic trends, it's vital to prioritize monetary policy shifts as a key factor in investment decisions.

• Radiation Oncology Journal
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• v.16 no.2
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• pp.147-157
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• 1998

Purpose : The aim of this retrospective study is to assess the necessity of s1aging laparotomy in the management of supradiaphragmatic CS I-II Hodgkin's disease. Prognostic factors and the usefulness of prognostic factor groups were also analyzed. Materials and Methods : From 1985 to 1995, fifty one Patients who were diagnosed as supradiaphragmatic CS I-II Hodgkin's disease at Yonsei Cancer Center in Seoul, Korea were enrolled in this study Age range was 4 to 67 with median age of 30. The number of patients with each CS IA, II A, and IIB were 16, 25, and 10, respectively. Radiotherapy(RT) was delivered using 4 or 6 MV photon beam to a total dose of 19.5 to 55.6Gy (median dose : 45Gy) with a 1.5 to 1.BGy per fraction. Chemotherapy(CT) was given in 2-12 cycles(median : 6 cycles). Thirty one Patients were treated with RT alone, 4 patients with CT alone and 16 patients with combined chemoradiotherapy. RT volumes varied from involved fields(3), subtotal nodal fields(18) or mantle fields(26). Results : Five-year disease-free survival rate(DFS) was $78.0\%$ and overall survival rate(05) was $87.6\%$. Fifty Patients achieved a complete remission after initial treatment and 8 patients were relapsed. Salvage therapy was given to 7 patients, 1 with RT alone, 4 with CT alone, 2 with RT+CT. Only two patients were successfully salvaged. Feminine gender and large media-stinal adenopathy were significant adverse prognostic factors in the univariate analysis for DFS. The significant adverse prognostic factors of OS were B symptom and clinical stage. When patients were analyzed according to European Organization for Research and Treatment of Cancer(EORTC) prognostic factor groups, the DFS in Patients with very favorable, favorable and unfavorable group was 100, 100 and $55.8\%$(p<0.05), and the 05 in each patients' group was 100, 100 and $75.1\%$(p<0.05), respectively. In very favorable and favorable groups, the DFS and 05 were all $100\%$ by RT alone, but in unfavorable group, RT with CT had a lesser relapse rate than RT alone. The subtotal nodal irradiation had better OFS than mantle RT in patients treated with RT. Conclusion : In present study, the DFS and OS in patients who did not undergo s1aging laparotomy were similar with the results in the literatures of which patients were surgically staged. Therefore, we may suggest that staging laparotomy would not influence the outcome of treatments. In univariate analysis, gender, large mediastinal adenopathy. B symptoms and clinical stage were significant prognostic factors for the survival rate. We confirm the usefulness of EORTC prognostic factor groups which may be a good.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.41-61
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• 2023

The universal form of life in the era of the 4th industrial revolution can probably be summarized as the keyword "non-face-to-face". In particular, in terms of consumption activities, face-to-face contact is gradually changing to a system that minimizes, and offline stores are rapidly changing to non-contact services through kiosks and robots. The social structure is also changing with the passage of time, and most fundamentally, our dietary consumption patterns are changing. In particular, the increase in single-person households and the aging population are having a great impact on changes in the food service industry, which is closely related to dietary life. The HMR (Home Meal Replacement) market has grown significantly as the labor of cooking at home has decreased and the use of substitute foods has increased. As the size of the market has grown, the types of businesses that provide products have also diversified. The development of technology, non-face-to-face culture, and corporate management efficiency are intertwined, and unmanned stores are spreading recently. In this study, service quality attributes of HMR unmanned stores, where competition is gradually intensifying, are classified, and service quality classification using the Kano model and Timko's customer satisfaction coefficient are calculated to provide implications for service management based on customer satisfaction. As a result of the analysis, 'products with short cooking time' and 'variety of products (menu)' were classified as attractive qualities, and 'cleanliness inside/outside of the store' and 'products at reasonable prices' were classified as unified quality. In addition, 'convenience of self-checkout process' was classified as a natural quality, and 'convenience of in-store passage' was classified as an indifferent quality. Furthermore, when the service factor was satisfied within the HMR unmanned store, the factor with the highest satisfaction coefficient was 'product (menu) variety', and the factor with the highest dissatisfaction factor was 'convenience of self-checkout process'. Through the results of this study, it is intended to derive priorities in service quality management of HMR unmanned stores and provide strategic implications for related businesses.