• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.282-287
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• 2011

Sirt1, a nicotinamide adenine dinucleotide ($NAD^+$)-dependent histone deacetylase, is known to deacetylate a number of proteins that are involved in various cellular pathways such as the stress response, apoptosis and cell growth. Modulation of the stress response by Sirtuin 1 (Sirt1) is achieved by the deacetylation of key proteins in a cellular pathway, and leads to a delay in the onset of cancer or aging. In particular, Sirt1 is known to play an important role in maintaining genomic stability, which may be strongly associated with a protective effect during tumorigenesis and during the onset of aging. In these studies, Sirt1 was generated in stably expressing cells and during the stimulation of DNA damage to examine whether it promotes survival. Sirt1 expressing cells facilitated the repair of DNA damage induced by either ionizing radiation (IR) or bleomycin (BLM) treatment. Fastened damaged DNA repair in Sirt1 expressing cells corresponded to prompt activation of Chk2 and ${\gamma}$-H2AX foci formation and promoted survival. Inhibition of Sirt1 enzymatic activity by a chemical inhibitor, nicotinamide (NIC), delayed DNA damage repair, indicating that promoted DNA damage repair by Sirt1 functions to induce survival when DNA damage occurs.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.4
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• pp.303-309
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• 2008

Deficiency of collagen regeneration, denaturalization of elastic fibers, and promotion of reactive oxygen species formation are important factors for deterioration of skin function. They induce wrinckle formation and decrease skin elasticity. Vitamin C and its derivatives have been used as cosmetic ingredients for anti-aging effects but their chemical instability has been a major problem. In an attempt to develop a novel anti-aging agent with a improved stability and bioactivity, the anti-wrinkle effect of 3-O-cetyl-L-ascorbic acid (VCCE), a new vitamin C derivative, was investigated in this study. VCCE increased procollagen type-1 synthesis in a dose-dependent manner (149% at 0.002%) in cultured fiboroblasts. Its potent anti-wrinkle effect was confirmed in vivo by analyzing human skin replica by a visiometer and the PRIMOS system. It did not cause any irritation in human patch test. Taken together, our findings suggest that the VCCE has potential benefits applicable to cosmetics for anti-wrinkle effects.

• Journal of Korean Medical classics
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• v.24 no.5
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• pp.1-10
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• 2011

According to "Dongeuibogam(東醫寶鑑)", "the Shinnong Herb Bible(神農本草經)", "Chamdonggo(參同攷)", come to the conclusion about medical thought of "the Zhouyi Cantongxie(周易參同契)". Alchemy is a common field both on the eastern and western civilization, but a process of development is different. Ancient chinese alchemist made a study on external alchemy, but harmful consequences of external alchemy was consecutive, many scholars had turned their interest on internal alchemy which is related in human meridian biology and spirit. In the western alchemy has developed to make a study on analytic psychology and science of religion. Most importantly, the eastern and western alchemy have something in common what at the point of the perfection of self is similar, but the name is different, for example in the eastern alchemy we can be immortals and take a spiritual enlightenment with the elixir of life, in the western we can take a cure of souls as a christian. As for internal alchemy, "Cantongxie(參同契)" gives influence to the theories such as the theory of danjeon(lower part of the abdomen), evolution, aging, and life nurturing. Especially, the theory of danjeon shows such merit for studying since it is similar to triple energizers(三焦) and the theory of qi street(氣街) of oriental medicine. The study on "Cantongxie(參同契)" was achieved in Korea too, especially Chosun dynasty. "Candongkao (參同攷)" by Seo Myung-eung(徐命膺, 1716~1787) are representative. According to "Candongkao(參同攷)", Geon(乾), Gon(坤), Gam(坎), and Ri(離), the four trigrams for divination, each are affiliated with lungs, spleen, kidneys, and heart. Nowadays the study on alchemy correspond with modern trends, which are anti-aging and living without any disease. If processed mineral drugs is assured for stability, it can be used for incurable diseases such as cancer.

• KIEAE Journal
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• v.11 no.6
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• pp.109-115
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• 2011

Recently the Elderly with dementia is increasing in Korea with rapid aging of the population. In addition to increasing a number of nuclear family and women's advancement in society, people are less capable of supporting family with dementia. In response, the Seoul city increased welfare facilities for the elderly with dementia about two times for one year. I think that the quantitative portion of facility get to meet the requirements but it is lack of qualitative one in fact. Therefore, the space for the elderly can keep up with the falloff of mental and physical functions, dementia and geriatric diseases according to aging and careful consideration about the space considering stability and convenience is required. At this point, this study has the purpose to plan a daycare center which reflects the characteristics of the elderly to protect them within the community safely and comfortably. As for the research method, case study was conducted to understand the overall situation on the space plan of the daycare center for 3 daycare centers located in Seoul and found out problems. From the generalization of the above study, a space plan for a daycare center considering the characteristics of the elderly was provided. The composition of Dementia welfare facility should be carefully planned to fit characteristics of the patient's behaviors.

• Korea Real Estate Review
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• v.28 no.3
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• pp.53-64
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• 2018

OECD countries have been stimulating private pensions instead of public pensions because the financial stability of public pensions has been threatened by the aging population. Korea, which has the fastest aging population in the world, has been following the recommended policies of major countries. Unlike major economies, however, most of Korea's household assets are composed of real estate assets. Due to the economic and social importance of real estate assets in Korea, the wealth effect of real estate has been used as a major tool in macroeconomic policy. This study analyzed the effect of real estate value changes on the contribution of private pensions (personal pension + retirement pension). Utilizing a two-way, fixed effect model with the balanced panel data of the National Survey of Tax and Benefit, empirical results presented that the private pension contribution increased by 0.171% when the value of real estate increased by 1%. Thus, real estate value changes were analyzed as positive for retirement preparation through private pension. These results suggested that if the real estate market would shrink in the future, consumption would decrease, and the degree of preparation for retirement might be smaller.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.228-237
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• 2013

Paper relics are affected by a number of complex physical, chemical, biological and artificial damaging factors due to the vulnerability of organic materials. Wet cleaning is a conservation treatment method for removing pollutants from paper artefacts. This study was carried out in order to analyse the effect of wet cleaning on Hanji (Traditional Korean paper made from mulberry trees) which is the main material used in Korean paper relics (historical paper documents). For this study, the color change and folding endurance of artificially degraded paper was analysed before and after immersion wet cleaning. The result showed that washing each twice in 30 minutes is the most appropriate method for obtaining cleaning efficiency and material stability.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.6
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• pp.517-531
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• 2021

The water supply facilities of Korea have achieved a rapid growth, along with the other social infrastructures consisting a city, due to the phenomenon of urbanization according to economic development. Meanwhile, the level of water supply service demanded by consumer is also steadily getting higher in keeping with economic growth. However, as an adverse effect of rapid growth, the quantity of aged water supply pipes are increasing rapidly, Bursts caused by pipe aging brought about an enormous economic loss of about 6,161 billion won as of 2019. These problems are not only worsening water supply management, also increasing the regional gap in water supply services. The purpose of this study is to classify hazard evaluation indicators and to rank the water distribution network hazard by cluster using the TOPSIS method. In conclusion, in this study, the entropy-based multi-criteria decision-making methods was applied to rank the hazard management of the water distribution network, and the hazard management ranking for each cluster according to the water supply conditions of the county-level municipalities was determined according to the evaluation indicators of water outage, water leakage, and pipe aging. As such, the hazard ranking method proposed in this study can consider various factors that can impede the tap water supply service in the water distribution network from a macroscopic point of view, and it can be reflected in evaluating the degree of hazard management of the water distribution network from a preventive point of view. Also, it can be utilized in the implementation of the maintenance plan and water distribution network management project considering the equity of water supply service and the stability of service supply.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.3
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• pp.131-139
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• 2011

This study was carried out to examine the stability of $Na_2CO_3-H_2O_2$ carbonate solution with aging time in the dissolving solution after oxidative dissolution of U by a carbonate solution, the Cs/Re filtrate after selective precipitation of Cs and Re (as a surrogate for Tc), and the acidification filtrate after precipitation of U by acidification, respectively. The compositions of dissolving solution were not changed with ageing time, and the selective precipitation of Re and Cs was also not affected without regard to the aging time of dissolving solution. The successive removal of Cs and Re from a carbonate dissolving solution was possible. However, the recovery yield of U by acidification was decreased with increasing the aging time of the dissolving solution and the Cs/Re-filtrate, respectively, because U was converted from the uranyl peroxocarbonato complex to the uranyltricarbonate in the solution aged for a long time. Accordingly, it is effective that a dissolving solution and a Cs/Re filtrate are treated within the aging of 7 days, respectively, in order to recover U more than 99%. On the other hand, the recovery of U was carried out in order of the oxidative dissolution of U selective precipitation of Re and Cs precipitation of U by acidification. Almost all of U and a part of FP were co-dissolved in oxidative dissolution step. Over 99% of Re and Cs from the FP co-dissolved with U could be removed by a TPPCl (tetraphenylphosphonium chloride) and a NaTPB (sodium tetraphenylborate), respectively. U was precipitated nearly 100% by acidification to pH 4. Therefore, it was confirmed that the validity of recovery of U by precipitation methods from a SF (spent fuel) in the $Na_2CO_3-H_2O_2$ solution.

• The Journal of Advanced Prosthodontics
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• v.13 no.3
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• pp.160-171
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• 2021

Purpose. This in-vitro study evaluated and compared the color stability of 3D-printed and conventional heat-polymerized acrylic resins following aging, mechanical brushing, and immersion in staining medium. Materials and methods. Forty disc-shaped specimens (10 mm in diameter and 3 mm thick) were prepared from two 3D-printed [DentaBASE (DB) and Denture 3D+ (D3D)] and one conventional polymethylmethacrylate (PMMA) denture materials. The specimens were thermo-cycled, subjected to mechanical brushing, and were immersed in either coffee, lemon juice, coke, or artificial saliva (AS) to simulate one and two years of oral use. Color measurements of the specimens were recorded by a spectrophotometer at baseline (T0), and after one (T1) and two years (T2) of simulation. The color changes (ΔE) were determined and also quantified according to the National Bureau of Standards (NBS) units. Descriptive statistics, followed by factorial ANOVA and Bonferroni post-hoc test (α=.05), were applied for data analysis. Results. The independent factors, namely material, staining medium, and immersion time, and interaction among these factors significantly influenced ΔE (P<.009). Irrespective of the materials, treatments, and time, the highest and the lowest mean ΔEs were observed for PMMA in lemon juice (4.58 ± 1.30) and DB in AS (0.41 ± 0.18), respectively. Regarding the material type, PMMA demonstrated the highest mean ΔE (2.31 ± 1.37), followed by D3D (1.67 ± 0.66), and DB (0.85 ± 0.52), and the difference in ΔE between the materials were statistically significant (P<.001). All the specimens demonstrated a decreased color changes at T2 compared to T1, and this difference in mean ΔE was statistically significant (P<.001). Conclusion. The color changes of 3D-printed denture resins were low compared to conventional heat polymerized PMMA. All the tested materials, irrespective of the staining medium used, demonstrated a significant decrease in ΔE values over time.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.367-375
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• 2009

Recently, more focus is shift to imbalances in aggregate market supply and demand and an exhaustion of natural resources. In this situation, Electric arc furnace oxidizing slag (EAF slag) has high application possibility as aggregate for concrete due to similar property with general aggregate. However, it is inherent the problem which causes pop-out by free-CaO contained in slag In this study, we've got the plan to assure the chemical stability of EAF slag, and then experimentally tested the mechanical performance and durability for the fine aggregate used EAF slag. On this test result, we suggest the application plan. At the result of this study, it shows that EAF slag would reduce the surface defect such as pop-out due to natural aging for the fixed hour and adjustment the grain size of EAF slag. And mechanical performance and durability according to the replacement rate of concrete service, were revealed more than equal or equal compare to general aggregate. Hereafter, quality control must precede not to impede the beauty of concrete surface as assure the safety for aging and processing. And, to establish the environmental resource recycling system for by-products of steel, it should be made development of various application and guideline of quality control for the EAF slag aggregate. Moreover, it must be constantly studied all kind of engineering performance and durability for related to this study.