• Molecules and Cells
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• v.26 no.5
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• pp.427-435
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• 2008

In this review, we discuss the genes and the related signal pathways that regulate aging and longevity by reviewing recent findings of genetic longevity models in rodents in reference to findings with lower organisms. We also paid special attention to the genes and signals mediating the effects of calorie restriction (CR), a powerful intervention that slows the aging process and extends the lifespan in a range of organisms. An evolutionary view emphasizes the roles of nutrient-sensing and neuroendocrine adaptation to food shortage as the mechanisms underlying the effects of CR. Genetic and non-genetic interventions without CR suggest a role for single or combined hormonal signals that partly mediate the effect of CR. Longevity genes fall into two categories, genes relevant to nutrient-sensing systems and those associated with mitochondrial function or redox regulation. In mammals, disrupted or reduced growth hormone (GH)-insulin-like growth factor (IGF)-1 signaling robustly favors longevity. CR also suppresses the GH-IGF-1 axis, indicating the importance of this signal pathway. Surprisingly, there are very few longevity models to evaluate the enhanced anti-oxidative mechanism, while there is substantial evidence supporting the oxidative stress and damage theory of aging. Either increased or reduced mitochondrial function may extend the lifespan. The role of redox regulation and mitochondrial function in CR remains to be elucidated.

• Journal of the Korean Data and Information Science Society
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• v.27 no.2
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• pp.437-449
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• 2016

This study empirically analyzes casual relationships among psychological and financial factors influencing the subscription of individual pension and identifies mediation effect by the structural equation model. The analysis based on survey data (N=928) from common people living in the seven major cities in Korea shows that potential longevity, coping efficacy to the financial risks from longevity, subjective knowledge on longevity (cognitive factor), trust in insurers (social factor), and financial literacy(financial factor) are key players exercising direct influence over the subscription of individual pension. It also has been shown that affect on longevity, potential longevity, trust in government, and coping efficacy influence the emotions on longevity, fear and worry, and emotions on longevity are not significant in explaining the subscription of individual pension. Trust in insurers and financial knowledge of prospects have also been reaffirmed to be crucial factors in the activation of individual pension subscription.

• Communications for Statistical Applications and Methods
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• v.28 no.6
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• pp.655-671
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• 2021

This study analyzes the premium risk of insurers in Korea, which is expected to experience the fastest population aging in the world. Based on the Lee-Carter model, we generate 10,000 scenarios for the number of future survivors in the group of the 10,000 policyholders of life annuity. According to the result of simulation study, the probability of insurer's loss for both groups of male and female policyholders is very low. This result indicates that the premium risk of insurers is not as great as the insurer's concern. This study also suggests introduction of the longevity swap as an alternative to manage the premium risk for the insurer which sells life annuity products. The longevity swap allows insurers to hedge premium risk and reduce capital burden due to the premium risk inherent in life annuity. This study also shows through examples that the counterparty of swap deal may have excess profit in exchange for taking premium risk.

• BMB Reports
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• v.52 no.1
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• pp.70-85
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• 2019

Reduction of insulin/insulin-like growth factor 1 (IGF1) signaling (IIS) extends the lifespan of various species. So far, several longevity mouse models have been developed containing mutations related to growth signaling deficiency by targeting growth hormone (GH), IGF1, IGF1 receptor, insulin receptor, and insulin receptor substrate. In addition, p70 ribosomal protein S6 kinase 1 (S6K1) knockout leads to lifespan extension. S6K1 encodes an important kinase in the regulation of cell growth. S6K1 is regulated by mechanistic target of rapamycin (mTOR) complex 1. The v-myc myelocytomatosis viral oncogene homolog (MYC)-deficient mice also exhibits a longevity phenotype. The gene expression profiles of these mice models have been measured to identify their longevity mechanisms. Here, we summarize our knowledge of long-lived mouse models related to growth and discuss phenotypic characteristics, including organ-specific gene expression patterns.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.326-335
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• 2011

When bougainvilleas are subjected to indoor low-light conditions, flower bracts regularly abscise. This study elucidates the effects of plant growth regulators on bract longevity of potted bougainvillea. Potted 'Taipei Red' bougainvillea in four different bract development stages were treated with 1-MCP (1-methylcyclopropene), NAA (1-naphthaleneacetic acid), SNA (sodium salt of naphthaleneacetic acid), IBA (indolebutyric acid), BA (6-benzylaminopurine), $KH_2PO_4$ (potassium dihydrogen phosphate), Put (diamine putrescine), SA (salicylic acid), or STS (silver thiosulfate) and were moved to indoor low-light conditions after treatments. Experimental results indicate that 1-MCP, NAA, SNA, BA, Put, and SA prolonged bract longevity, and this effect increased as bract stage increased. The effect of STS was significant in early bract stages and decreased as bract stages increased. Additionally, 1-MCP, NAA, SNA, BA, Put, SA, and STS treatment significantly reduced endogenous ACC (1-aminocyclopropene-1-carboxylate) content and ACC oxidase activity, suggesting that the inhibition of ethylene production was achieved via physiological metabolism. However, treatment with IBA or $KH_2PO_4$ had no effect on the bract longevity at any stage. In the combined chemical treatments, NAA + STS or NAA + SA were effectively for prolonging bract longevity and contained less protein or chlorophyll degradation, decrease ACC oxidase or ethylene production than the control. In conclusion, we propose that combined chemical treatment significantly prolonged the bract longevity and more effectively than single chemical treatment at any stage.

• Asia-Pacific Journal of Business
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• v.7 no.1
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• pp.11-30
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• 2016

The study specifically aimed to identify factors affecting business longevity. It focused on knowing how embroidery enterprises managed to persist in the industry for many years despite the competitive business environment. After discovering the significant relationships of such factors to longevity, problems experienced by the enterprise cluster were ascertained in order to come up with recommendations that can be proposed to the enterprise owners. Embroidery entrepreneurs have been experiencing a continuous decline in sales due to lack of innovation and intense competition. In the evaluation of their personal entrepreneurial competencies, they scored low on risk-taking, persuasion and networking, and opportunity seeking; thus, implying that these are their weaknesses. On the other hand, the statistical results of this study say that longevity is a function of the entrepreneur's competencies (i.e., persistence, commitment to work contract, demand for quality and efficiency, information seeking, and systematic planning or monitoring), the generation currently managing the business, competition, and the customer's preferences. These results suggest that these independent variables are significant and are deemed critical to business longevity. Thus, entrepreneurs have to find ways on how to use these competencies as an advantage in reinventing their businesses and in reviving their industry.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.466-470
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• 2011

The purpose of this study was to investigate the anti-cancer effects of Carthami Flos in some kinds of human gastric cancer cells. We used two kinds of human gastric cancer cell lines, such as AGS cells and MKN45 cells. We examined cell death by MTT assay and observed the morphological changes with Carthami Flos. Also, we showed that the combination of sub-optimal doses of Carthami Flos and cisplatin noticeably suppresses in AGS cells and doxorubicin in MKN45 cells. Furthermore, we studied the caspase 3 activity to identify the apoptosis. Therefore, our findings provide insight into unraveling the effects of Carthami Flos in human gastric cancer cells and developing therapeutic agents against gastric cancer.

• Korean Journal of Health Education and Promotion
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• v.20 no.4
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• pp.41-50
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• 2003

Objectives： The purpose of this paper is to analyze longevity factors of 507 centenarians in the Republic of Korea. Methods： This paper is designed to survey physical, mental, socio-demographic and dietary factors of 507 centenarians. The data was collected by means of telephone interview from 1999 to 2001. The survey directly contacted centenarians who were able to communicate, or contacted the centenarians caregivers. The association between longevity factors of centenarians was verified by odds ratio of logistic regression. Results： Female centenarians appeared to be non-smokers more often than males (OR＝4.06, CI＝2.06, 7.98). The longevity of persons with a small waist circumference was attributed to health promotion through eating lightly as well as keeping active including walking(OR＝2.37, CI＝1.36, 4.14). A higher probability for longevity is found among optimists who live a happy life and 1aught every day (OR＝26.15, CI＝11.61, 58.89). Among centenarians, vegetarians were shown to be light eaters. More ratios of vegetarians among centenarians included those who reside in a rural district, eat bean paste soup everyday, and consume small quantities of meat (OR＝5.12, CI＝3.24, 8.08). Conclusion： Women, manual workers, under poor to middle economic status, rural residents, optimists, light eaters, vegetarians and non-smokers seemed to have a higher probability of becoming centenarians in The Republic of Korea.

• Korean Journal of Oriental Medicine
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• v.17 no.2
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• pp.129-134
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• 2011

Objective : The purpose of this study was to investigate the anti-cancer effects of Carthami Flos in some kinds of human colorectal adenocarcinoma cells. Method : We used two kinds of human colorectal adenocarcinoma cell lines, such as HT-29 and WiDr cells. We examined cell death by MTT assay and observed the morphological changes with Carthami Flos. Result : We showed that the combination of sub-optimal doses of Carthami Flos and cisplatin noticeably suppresses in HT-29 cells and doxorubicin in WiDr cells. Furthermore, we studied the caspase 3 activity to identify the apoptosis. Conclusion : Our findings provide insight into unraveling the effects of Carthami Flos in human colorectal adenocarcinoma cells and developing therapeutic agents against colorectal cancer.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.158-175
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• 2005

Statement of problem. Every effort has been continually made to obtain objectivity in measuring the longevity of fixed restorations, such as by establishing unified judgement standard for deciding success and adopting statistical method that analyzes the data of successful and failed cases at the same time. In Korea, however desired level of development has not to be made in this field yet. Purpose. This study, adopting California Dental Association (CDA) quality evaluation system, established objective standard for deciding success, and inferred the longevity of fixed restorations and their failure analysis through adopting Kaplan-Meier survival analysis. Material and method. In order to assess the longevity of flxed restorations serviced in Korea and causes of failure, a total of 1109 individuals (aged 15-74, 716 women and 393 men loaded with 2551 unit fixed restorations, and 1934 abutments) who lived in Kyung-In Province were examined and the findings were as follows : Results. 1. Length of service of fixed restorations serviced in Korea was 6.86$\pm$0.15 yr (mean), 5.5 yr (median), and the rate of success was 65.82% in 5 year survival, and 21.15% in 10 year survival. 2. When there was patient's need for replacing old prosthetics, longevity of fixed restorations was 7.51$\pm$0.27 yr (mean), 7 yr (median), and the rate of success was 61.08% in 5 year survival, and 17.57% in 10 year survival. 3. Longevity of fixed restorations was longest in the over-sixty age group(9.21$\pm$0.66) and that of the teen age group(3.39$\pm$0.28) was shortest (p<0.05). 4. Longevity of fixed restorations of women (7.38$\pm$0.18 years) was longer than that of men (6.00$\pm$0.26) (p<0.05). 5. As for the provider factor (such as unlicensed performers, university hospitals, and private clinic), there was no statistically significant difference in longevity of fixed restorations. 6. Defective margin (34.78%). periodontal disease (12.15%), periapical involvement (11.73%), was the most frequent causes of failure and poor esthetics group showed the longest life above all (p<0.05). Actual frequent causes of failure after removing old prosthetics were defective margin, periapical involvement, periodontal disease and uncemented restoration. In 75.67% of the cases, abutment state after removing old prosthetics was good enough for loading another prosthetics. 7. There was found to have statistically significant influence between longevity of single crown (6.35$\pm$0.20 yr) and that of 3 unit fixed restorations (7.60$\pm$0.30 y) (p<0.05). In each case the most frequent cause of failure was defective margin. 8. The number of cantilever pontic, pontic/abutment ratio, oral hygiene status were found to have no statistically significant influence on longevity of fixed restorations in all groups (p>0.05). 9. Longevity of fixed restorations made of non precious metal was longest (9.60$\pm$0.40 yr) semi precious and precious trailing behind(p<0.05). 10. Group function group (37.04%) and partial group function group (44.62%) were predominant in frequency but showed no correlation between them and among different types of occlusal plane and different types of occlusal surface (p>0.05). 11. Longevity of fixed restorations was longest in the centric interference group(9.35$\pm$0.62) (p<0.05) among different types of occlusal interference. Conclusion. We found that longevity of fixed restorations serviced in Korea is affected by age, gender and type of material, and that most frequent cause of failure is defective margin. In order to assess the accurate longevity of axed restorations, unified research design. overcoming inter-observer difference and establishing the objective research items are needed. Furthermore, it is thought that prospective approach through thorough study and regular follow-ups is needed just from the start of research. Nationwide detailed studies on length of service of fixed restorations manufactured in Korea are hoped to be conducted hereafter.