• Journal of the Korean GEO-environmental Society
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• v.21 no.10
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• pp.11-16
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• 2020

Korea's agricultural reservoir is one of the country's major infrastructures and plays an important role in people's lives. However, aging reservoirs are a risk for life and property. Currently, large and small dams and reservoirs have been constructed nationwide for more than 40 years of aging. Dams and reservoirs built nationwide are managed by various institutions. Therefore, it is difficult to manage all dams and reservoirs due to cost and time. Managers in the field with less management personnel and lack of expertise should be able to quickly identify risk factors for multiple reservoirs. In this study, risk factors such as seepage, leakage, settlement slide, crack and erosion were selected. To assess the risk of the items, we used the analytical hierarchical process (AHP), one of the Multi-Criteria Decision Making (MCDM) methods. The analysis showed that seepage has the greatest impact on reservoir collapse. It is judged that the priority of detailed diagnosis can be determined by evaluating the risk of dam reservoir collapse in a convenient way in advance using the calculated weight.

• Journal of Life Science
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• v.21 no.6
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• pp.884-892
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• 2011

This study was performed to investigate the increase of S-allylcysteine content, a biomarker of black garlic, during its aging period, as well as the serum lipid-lowering effects of black garlic extract in high fat diet fed rats. The highest content of S-allylcysteine was observed on the 15th day of the aging period. Sensory evaluation was also estimated to be extremely good on the 15th day of the aging period. High fat diet rats with induced hyperlipidemia were fed diets containing black garlic extract of low, medium, and high doses for 6 weeks. No significant difference in body weight gain and food efficiency was observed between normal, placebo and black garlic fed groups. Liver weight was significantly higher in black garlic fed groups than in the normal group. Total serum cholesterol and triglyceride were significantly lower in low, medium, and high dose groups than in the normal group. Also, HDL-cholesterol was significantly higher and LDL-cholesterol was significantly lower in black garlic diet fed groups than in the normal group. Hepatic levels including total lipid and cholesterol were especially decreased in the black garlic diet fed group than in the placebo group. These results suggest that black garlic intake reduces the levels of serum and hepatic cholesterol in high fat diet fed rats. In conclusion, black garlic has a potential to be used as a functional health food ingredient with beneficial effects on lowering cholesterol and triglyceride levels.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.623-634
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• 2005

Human periodontal ligament fibroblast(hPDLF) is very important to cure periodontal tissue because it can be diverged into various cells. This study examined the expression of MMP-1, TIMP-1, periodontal ligament specific PDLs22, Type I collagen, Fibronectin, TIMP-2, telomerase mRNA in a replicative senescence of hPDLF. The periodontal ligament tissue was obtained from periodontally healthy and non-carious human teeth extracted for orthodontic reasons at the Chosun University Hospital of Dentistry with the donors' informed consent. The hPDLF cells were cultured in a medium containing Dulbecco's modified Eagle medium(DMEM, Gibco BRL, USA) supplemented with 10% fetal bovine serum(FBS, Gibco BRL, USA) at 37C in humidified air with 5% $CO_2$. For the reverse transcription-polymerase chain reaction(RT-PCR) analysis, the total RNA of the 2, 4, 8, 16, 18, and 21 passage cells was extracted using a Trizol Reagent(Invitrogen, USA) in replicative hPDL cells. Two passage cells, i.e. young cells, served as the control, and ${\beta}-actin$ served as the internal control for RT-PCR The results of this study about cell morphology and gene expression according to aging of hPDLF using RT-PCR method are as follows: 1. The size of hPDLF was increased with aging and it was showed that the hPDLF was dying in the final passage. 2. PDLs22 mRNA was expressed in young hPDLF of the two, four, and six passage. 3. TIMP-1 mRNA was expressed in young hPDLF of the two and four passage. 4. There was a tendency that MMP-1 mRNA was weakly expressed over eighteen. 5. Type 1 collagen mRNA was expressed in almost all passages, but it was not expressed in the final passage. 6. Fibronectin mRNA was observed in all passages and it was weakly expressed in the final passage. 7. TIMP-2 and telomerase mRNA were not expressed in this study. Based on above results, it was observed that PDLs22, Type 1 collagen, Fibronectin, MMP-1. and TIMP-1 mRNA in hPDLF were expressed differently with aging. The study using the hPDLF that is collected from healthy patients and periodontitis patients needs in further study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.1
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• pp.104-110
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• 2007

Temperature rise characteristics of medium voltage class transformers and dielectric characteristics of its insulation oil according to the loading rate were investigated using the transformer that has thermocouples embedded in the windings. The hottest-spot of the transformer locates at about 2/3 height of the windings where they adjoin each other among the 3 phase windings. The temperature difference between the hottest-spot and top-oil is about $17[^{\circ}C]$ and the value keeps uniformly in short time after changing the loading rate. Capacitance of the oil varies in inverse proportion to temperature and the inclination rate is about -0.0106 that is not dependent on the aging rate. On the other hand the capacitance is increased depending on the aging rate, so the capacitance characteristics of the oil could be applied to the diagnostic technique.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.387-412
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• 2003

Influence of gelatinase on basement membrane (BM) structure was investigated by using a skin equivalent (SE) model. The results showed that (1) gelatinase produced by cells degraded the BM and (2) the addition of matrix metalloproteinase-specific inhibitor to the SE medium accelerated the formation of BM structure, indicating that gelatinase is involved in BM impairment. The activity of gelatinase was also studied in healthy human facial skin tissues. The result of in situ zymography revealed gelatinase activity around the basal layer of the epidermis, where BM integrity was severely compromised. Therefore, this enzyme was suggested to be associated with BM decomposition in human facial skin. To assess the behavior of gelatinase in stratum corneum (SC) non-invasively, an immunological study was performed. Since positive immunostaining of pro-gelatinase B was observed in SC stripped from sun-exposed skin, whereas no positive staining detected in SC of non-irradiated skin, gelatinase in the epidermis could be non-invasively detected by measuring gelatinase in SC. Gelatinase in SC of healthy female volunteers was monitored using a special film that sensitively and conveniently detects gelatinase. Ninetr percent of SC from facial skin (l00 women, 40's-50's) was gelatinase-positive. On the other hand, SC from non-irradiated skin was negative. These results strongly suggest that (1) gelatinase is constantly produced in the facial epidermis of most middle-aged woman during their daily life, and (2) the enzyme might be involved in the aging-related degeneration of both BM and the matrix fibers of the upper layer of the dermis, acting as a very important aging factor. Strong inhibitory activity against gelatinase was found in turmeric extract and identified curcumin as the major ingredient. Topical application of cream containing turmeric extract significantly decreased the number of gelatinase-positive SC clusters in human facial skins. These results indicated that turmeric is an effective ingredient to prevent skin from photo aging by suppressing chlonically upregulated gelatinase activity by UV and to improve skin condition.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.148-161
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• 2018

A traffic fatality by young people marked average annual decrease of 4.5% since 2011. Meanwhile, a traffic fatality by senior over 65 years old marked average annual increase of 7.9% for the last five years which means that the annual increase of traffic fatality by senior will be a serious problem. This study started questioning that senior drivers over 65 years old did not retain the same causal factor of fatal traffic accidents and thus extensively analyzed a risk of it by age group quantitatively, dividing the senior driver group into the early, middle and latter stages. Depending on the aging level, the risk of traffic fatality showed a wide difference in seven different types of traffic accidents generally, and happened to increase with latter and middle parts of the senior driver more than the early part. Therefore, this study proposes four policy suggestions: 1) The senior driver need to be offered customized driving educations and the improvement of road environment is also recommended. 2) Political assistance is needed to support and guide a safety related technology installation for the new or existing car. 3) Renewal of driving license and an aptitude test(physical examination, cognitive test) for drivers over 75 years old should take in a less than 3 years and an additional road test is needed as occasion demands. 4) Like the United States and Europe, development and extension of customized treatment guidebook for medical teams who examine senior drivers is needed and establishment of education and administration system that a supervisor of driving license renewal can impose safety restriction and American anonymity reporting system is considered to institutionalize in the medium to longer term.

• Korean Journal of Materials Research
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• v.8 no.9
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• pp.807-812
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• 1998

Interfacial reaction and mechanical properties between Sn-Bi-X ternary alloys(X : 2Cu. 2Sb 5In) and Cu-substrate were studied. Cu/solder joints were subjected to aging treatments for up to 60days to see interfacial reaction at $100^{\circ}C$ and then were examined changes of microstructure and interfacial compound by optical microscopy, SEM and EDS. Cu/solder joints were aged to 30days and then loaded to failure at cross head speed of 0.3mm $\textrm{min}^{-1}$ to measure strength and elongation. According to the result of EDS, it is supposed that the soldered interfacial zone was composed of $\textrm{Cu}_{3}\textrm{Sn}$ and $\textrm{Cu}_{6}\textrm{Sn}_{5}$. According to the tensile test of Cu/solder joint, joint strength was decreased by aging treatment. Fractographs of Cu/Sn-Bi solder detailed the effect of aging on fracture behavior. When intermetallic was thin, the fracture occurred through the solder. But as the interfacial intermetallic is thickened, the fracture propagated along the intermetallic/solder interface.

• Journal of Digital Convergence
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• v.15 no.5
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• pp.505-515
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• 2017

This study examines the verification of algorithm on resilience leisure programs for the productive aging of the new elderly in Korea. The subjects for this study were 525 new elderly who lived in metropolis, medium-sized cities and farming area. The reliability and validity test of the questionnaire were conducted by using SPSS 20.0 program; the results of tree analysis are as follows; First, The influential factor in the resilience leisure programs is subjective health status, desire for activity, interpersonal exchange and household income. The most influential resilience factor of algorithm is interpersonal relationship, self-regulating and affirmative. The structural algorithm of resilience was that low interpersonal relationship group related to the affirmative and high interpersonal relationship group related to the self-regulating.

• Korea Journal of Cosmetic Science
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• v.1 no.1
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• pp.1-9
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• 2019

The identification of compounds with anti-senescence activity in cell culture system is a first step in aging research. Given that pyruvate can be used energy source by conversion to acetyl-CoA in mitochondria, and protects cultured cell from various stress-induced cell damage and cell death, synthetic media (e.g., DMEM) often includes 1 mM pyruvate, which is very higher than the pyruvate concentration in human blood (approximately 30 ��M). However, the use of medium containing high concentration of pyruvate is not suitable for screening anti-senescence compounds, because pyruvate also protects against the cellular senescence of primary human dermal fibroblasts (NHDFs) through NAD+ generated during conversion to lactate. In this study, four extracts, i.e., Sprouted seed and fruit complex, Poncirus trifoliata fruit extract, Jaum balancing complex, and Prunus mume extract were used for evaluation of different anti-senescence effect in the absence or presence of 0.1 mM pyruvate, similar to the physiological pyruvate concentration. The senescence in NHDFs cultured with DMEM in the presence of 0.1 mM pyruvate (approximately the physiological concentration in human blood) is accelerated, as observed in pyruvate deprivation conditions. The cytotoxicity of the Poncirus trifoliata fruit extract was protected by pyruvate, and Jaum balancing complex and Prunus mume extract had anti-senescence activity in the presence of 0.1 mM pyruvate, but not in the absence of pyruvate. Given that pyruvate is a powerful protector against both cytotoxicity and cellular senescence, the screening of candidate agents for anti-senescence in high pyruvate conditions using an in vitro cell culture system is not valid. Therefore, we recommend the use of a low concentration of pyruvate to evaluate the anti-senescence effects of candidates, which is more similar to in vivo aging conditions than excessive stress-induced senescence models, to exclude the effect of excessive pyruvate in vitro.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.37 no.1
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• pp.17-28
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• 2024

Objectives : This study was conducted to reveal the scientific mechanism of the anti-skin aging activity of Kyung-Ok-Ko(KOK), which is highly useful as a Korean traditional medicine and functional food. Methods : The skin wrinkle and aging inhibitory activity of KOK was confirmed through in vitro experiments of human dermal fibroblast neonatal cell(HDFn) and in vivo of C. elegans, and hairless mouse(SKH-1). Results : The amount of the C-terminus of the collagen precursor in the HDFn cell culture medium treated with KOK using an enzymes-linked immunoassay kit. The group treated with KOK 200㎍/㎖ was a 28.3% increase of collagen precursor compared to the control group. KOK showed inhibitory activity of MMP-1 compared to the control group at a concentration of 200㎍/㎖. In addition, KOK 200㎍/㎖ showed significant inhibitory activity of thermal stress and an oxidative stress compared to the control group in C. elegans. Furthermore, KOK showed a concentration-dependent(100mg/kg and 500mg/kg) anti-wrinkle formation effect in UV-irradiated hairless mouse(SKH-1). Additionally, when KOK was administered to UV-irradiated hairless mice, an increase in procollagen -1 and -3 genes expression was observed, and mmp-1 and mmp-9 genes, which increase collagen decomposition, decreased with the administration of KOK. Conclusions : The skin aging inhibition mechanism of Kyung-Ok-Ko(KOK) is presumed to be achieved through suppressing thermal stress and oxidative stress, suppressing mmp-1 and mmp-9 genes, and increasing procollagen-1 and procollagen-3.