• Biomolecules & Therapeutics
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• v.24 no.1
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• pp.1-8
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• 2016

Alpha-ketoglutarate (AKG) is a key molecule in the Krebs cycle determining the overall rate of the citric acid cycle of the organism. It is a nitrogen scavenger and a source of glutamate and glutamine that stimulates protein synthesis and inhibits protein degradation in muscles. AKG as a precursor of glutamate and glutamine is a central metabolic fuel for cells of the gastrointestinal tract as well. AKG can decrease protein catabolism and increase protein synthesis to enhance bone tissue formation in the skeletal muscles and can be used in clinical applications. In addition to these health benefits, a recent study has shown that AKG can extend the lifespan of adult Caenorhabditis elegans by inhibiting ATP synthase and TOR. AKG not only extends lifespan, but also delays age-related disease. In this review, we will summarize the advances in AKG research field, in the content of its physiological functions and applications.

• Journal of Life Science
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• v.29 no.8
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• pp.888-894
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• 2019

Cartilage diseases, such as rheumatoid arthritis (RA) and osteoarthritis (OA), are associated with the loss of chondrocytes and degradation of articular cartilage. Recent studies revealed that inflammatory reactive oxygen species (ROS) and age-related oxidative stress can affect chondrocyte activity and cartilage homeostasis. We investigated changes in the levels of intracellular antioxidants during cellular senescence of primary chondrocytes from rat articular cartilages. Cellular senescence was induced by serial subculture (passages 0, 2, 4, and 8) of chondrocytes and measured using specific senescence-associated ${\beta}$-galactosidase ($SA-{\beta}-gal$) staining. ROS production increased significantly in the senescent chondrocytes. In addition, total glutathione (GSSG/GSH) and superoxide dismutase (SOD) levels and heme oxygenase-1 (HO-1) expression increased in senescent chondrocytes induced by serial subculture. Analysis of changes in intracellular antioxidant levels in articular cartilage from rats of different ages (5, 25, 40, and 72 wk) revealed that total glutathione levels were highest after 40 wk and slightly decreased after 72 wk as compared with those after 25 wk. SOD and HO-1 expression levels increased in accordance with age. Based on these results, we conclude that intracellular antioxidants may be associated with cartilage protection against excessive oxidative stress in the process of chondrocyte senescence and age-related cartilage degeneration in an animal model.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.346-355
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• 2014

This study was to investigate basic level of physical activity test that reflects activity of daily living(ADL) for institutionalized elderly women. The subjects were 105 elderly women over than 65 years living in long-term care facilities located in Daejeon and Chungnam. The measured eight items related to ADL were tested and the data was analyzed by descriptive statistics, one-way ANOVA, factors analysis and correlation. The results were statistically significant differences. Among eight test items, two factors(muscle strength and mobility) were extracted by principal component factor analysis(PCA). The two factors are appropriate domains for assessment of basic physical activity of institutionalized elderly women. By using Pearson's correlation, between two factors and age, the first principal component scores were significantly decreased with age increasing. Degradation of ADL must be prevented for institutionalized elderly women through maintain muscle strength and mobility.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.1
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• pp.33-37
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• 2013

Autophagy is a degradation process that acts in response to environmental stressors. Recently, autophagy has been detected in normal term, preeclamptic and intrauterine growth-restricted placentas. The object of this work was to investigate the presence of autophagy in first trimester voluntary interruption of pregnancy placental villi by the expression of autophagy-related proteins, light chain 3 (LC3), and Beclin-1. In first trimester placental villi laser scanning confocal microscopy (LSCM) analysis revealed LC3 and Beclin-1 immunoreactivity prevalently located in villous cytotrophoblasts. Using LSCM, LC3, and Beclin-1 were localized to the cytoplasm of the trophoblast layer in human full-term placentas. Beclin-1 expression and LC3 activation were confirmed by western blotting. These data emphasize that autophagy activation is different among cytotrophoblasts and syncytiotrophoblasts depending on the gestational age and thus we speculate that autophagy might play a prosurvival role throughout human pregnancy.

• Journal of Technologic Dentistry
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• v.36 no.1
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• pp.51-62
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• 2014

Purpose: Recently our country is rapidly aging population is growing. In the oral cavity of the elderly status of oral health-related quality of life to evaluate any impact. Methods: The survey used structured self administered questionnaires from April to May in 2011 in Daejeon and Chungcheong provinces to 277 people, analysis of the general characteristics of a frequency analysis method, the difference between the quality of life T/F test, whether oral self-according to the quality of life healthy oral health effects of the multiple regression analysis. Results: Award comes on the number of residual value, lower age all the more, smaller monthly income was small, but significant difference between them was no difference between gender. Residual value according to the number of differences in the quality of life of physical pain upper, physical disability, the lower the physical pain, physical disability, psychological disability were significant differences in degradation. Depending on oral maxillary prosthesis fitted to physical pain, psychological discomfort, physical disability, the lower the functional limitation, physical pain, there was a significant difference in physical disability. Conclusion: Status of the oral cavity of the elderly factors affecting the quality of life remaining in the lower dimensions, upper and lower prosthetics, self-aware state of oral health in order to improve the quality of life of elderly oral health education to be strengthened to increase the residual value, reducing their own prosthetic perceived oral health is health, so they feel it should be for the development of health education programs for the elderly should be.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1414-1418
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• 2017

Inhibition of advanced glycation end product (AGE) formation is a valuable therapeutic strategy for the regulation of diabetic complications. This study was conducted to identify potential therapeutic targets of anti-diabetic complications from irradiated mangiferin using AGE formation assay. Radiolytic degradation of the xanthone glucoside mangiferin by gamma-irradiation resulted in three degraded mangiferin analogues: mangiferdiol (1), mangiferinol (2), and isomangiferinol (3). Structures of the three newly generated compounds were characterized by interpretation of nuclear magnetic resonance ($^1H$, $^{13}C$ NMR, $^1H-^1H$ COSY, HSQC, HMBC, and NOESY) and mass spectroscopic data. The anti-diabetic complication of the generated mangiferin derivatives were tested using in vitro AGE formation method. Among the tested degraded products, mangiferinol (2) and isomangiferinol (3) exhibited significantly improved potency against AGE formation inhibitory activities with $IC_{50}$ values of $5.6{\pm}0.8$ and $7.6{\pm}0.9{\mu}M$, respectively. This result implies that xanthone derivatives generated from gamma-irradiated mangiferin might be beneficial for prevention of diabetic complication and related diseases.

• Journal of Dairy Science and Biotechnology
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• v.33 no.3
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• pp.179-196
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• 2015

Because of our aging population, there is increasing concern about the impact of dementia and age-related cognitive decline. Intense research efforts on effective dietary interventions for the prevention or amelioration of dementia and age-related cognitive decline have indicated that dairy products affect physiological health and potentially healthy brain function during aging. Milk is a rich source of proteins and peptides with nutritional and immunotropic activities. The preparation of biologically active proteins and peptides generally requires enzymatic degradation, chemical modification, or the addition of specific co-factors. Milk-derived preparations are widely available in the food industry in the form of hygiene products and infant formulas. However, milk-derived products could also be applied as preventive or therapeutic measures for a wide-range of pathological conditions not only in neonates and infants but also in adults, including the elderly. Because they have no adverse side effects, milk-derived proteins and peptides could be used as a supplementary treatment for dementia and age-related cognitive decline.

• Management & Information Systems Review
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• v.16
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• pp.139-159
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• 2005

In many countries the demographics clearly informs us that an aging population represent a serious problem. To this extent senior citizens welfare does matter it has developed into a public debate and genuine concern. it seems that the social issues are focused on how the socity views the social welfare policies. In a modern welfare state where the emphasis lies in pursing a high standard of living and thereby high quality of life. This does not cover the very well the old people in society, but the government clearly carries an obligation to look after and care for the retired & old people in the society. This obligation the social and economic impact that an old person faces as he/she grows old. it is important ensure that their lives carries a meaning and that they as a group will not be estranged from the mainstream of society just because they are considered to be part of the aging population. The key issues that must be addressed are 1) The impact of reduced spending power from less income. a lower income stream; 2) increasing health problems and costs; 3) the natural degradation of ones physical & mental powers; 4) and thereby an isolation from the public in general. So clearly the social policy related to the old people in society should be developed with the consent of what they believe is important to them. To ensure their minimum income level that a beneficiary of an old person's pension will receive, the monthly pension should be reflected by the official price index and be adjusted accordingly. by making the job market open for the senior citizens, expending the mandatory retirement age, give companiesincentives to hire senior citizens, there maybe an opportunity to extend to the aging population the possibility to continue to participate in the society at large.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.385-392
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• 2014

The isolators have been generally used to reduce a seismic force. If the isolators apply to the nuclear power plants(NPPs), the durability and capacity for the structures and equipments should be ensured during the life time. In this study, the long-term behavior of isolated NPPs was analyzed for ensuring the seismic safety. The properties of isolator due to the age-related degradation were analyzed. And the seismic behavior of isolated buildings was analyzed by considering the aging of rubber bearings in different temperature environments. According to the analysis results, the natural frequency of structures was increased with time. But the maximum acceleration and maximum displacement of isolated structures have not changed significantly. Although the damaged of structure did not occurred by aging of isolators, it was presented that the spectral acceleration at the target frequency of isolated structure increased with the temperature. Therefore the isolators in the isolated buildings should be carefully designed and manufactured considering the temperature-dependancy of rubber material.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.1
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• pp.10-18
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• 2016

RC(Reinfored Concrete) structures exposed to carbonation in urban city have durability degradation with extended service life and cracks in concrete causes a local accelerated carbonation. In the present work, crack effect on carbonation depth is investigated and the service life of RC structure is evaluated considering cracks from early age and time-dependent cracks based on the previous field investigation. DFP(Durability Failure Probability), safety index, and the related service life are calculated considering the time to crack width reaches to maximum crack width(0.3mm). The results with time effect on crack width show lower DFP and longer service life, which seems to be reasonable compared with conservative results from crack effect from initial stage. Furthermore, crack effect is evaluated to be insignificant on DFP and service life. The technique with time-dependent crack effect on carbonation can be effectively used for RC structure containing cracking in use.