• Food Science of Animal Resources
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• v.39 no.4
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• pp.655-667
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• 2019

The present study aimed at investigating the effects of dry- and wet-aging methods on flavor compounds and sensory properties of low fat Hanwoo beef muscles. All the beef samples were obtained from 2-grade carcasses of Hanwoo cows. The beef samples used in the dry- and wet-aging methods were prepared in the forms of quarter beef (bone-in) and cuts (boneless), respectively. The dry-aging was carried out at $2^{\circ}C-4^{\circ}C$ and humidity of 65%-85%, while the wet-aging was done at $1^{\circ}C$ for 0, 20, 40, and 60 d. At each aging time, three muscles: longissmus thoracis (LT), glutaeusmedus (GM) and semimembranosus (SM) were taken from the corresponding quarters and cuts, and used for the flavor compounds and sensory analyses. Results showed that both aging methods significantly increased the concentrations of flavor compounds and total amount of all classes of the flavor compounds as the aging time increased (p<0.05). In the dry-aging method, the GM and SM muscles presented significantly higher total amounts of pyrazines and sulfur-containing compounds compared to the LT muscle (p<0.05). Both the aging methods improved the eating quality attributes, indicating by increased scores of sensorial attributes with increased aging time for all the muscles studied (p<0.05). However, compared to the wet-aging, the dry-aging method resulted in significantly higher scores of tenderness and flavor for the GM and SM muscles after 40 to 60 d. Thus, postmortem aging, especially the dry-aging method could be used to improve eating quality attributes (tenderness and flavor) of low fat beef muscles such as GM and SM.

• Biomolecules & Therapeutics
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• v.17 no.2
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• pp.113-124
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• 2009

Aging is a multifaceted biological process that affects all organs and organ systems of the body. This review provides an up-to-date analysis of this highly exciting, rapidly changing field of science. The aging process is largely under genetic control but is highly responsive to diverse environmental influences. The genes that control aging are those that are involved with cell maintenance, cell damage and repair. The environmental factors that accelerate aging are those that influence either damage of cellular macromolecules, or interfere with their repair. Prominent among these are chronic inflammation, chronic infection, some metallic chemicals, ultraviolet light, and others that heighten oxidative stress. Other environment factors slow the aging process. Included among these agents are resveratrol and vitamin D. In addition, dietary restriction and exercise have been found to extend human lifespan. The various mechanisms whereby all these agents exert their influence on aging include epigenetic modification, chromatin maintenance, protection of telomeres, and anti-oxidant defense, among others. The complex process of aging remains under continued, intense investigation.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.1
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• pp.16-33
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• 2004

In Oriental medicine, aging is just a natural process like change of seasons. Ancient Oriental people accepted it as a natural thing to be growing older and to die at last. The science of aging has advanced dramatically. In the last 2 decades, advances in genetics and molecular biology have led to extraordinary new understandings in how cells age, how apoptosis programs cells to die, and how neuroendocrinology plays a role in the lifespan of organisms. Today, the matter of primary concern about aging is a cellular and mitochondrial damage of human body induced by reactive oxygen species(ROS). The skin aging can be divided into two areas, intrinsic(chronologic)-aging and photo-aging. There are lots of photo damage about skin aging. The skin is increasingly exposed to ultraviolet(UV) irradiation in life. Therefore, the risk of photo-oxidative damage of the skin induced by reactive oxygen species(ROS) has increased substantially. Nowadays, many people believe that they can stop or at least delay the process of aging. There are lots of treatments that promise to slow the process of aging and the associated ailments. Many of these treatments, for example, exercise, Vit E, Vit C therapy, hormone therapy, restrict diet, are gradually being subjected to clinical trials. But in spite of all efforts, researches and investigations, there is no single method or treatment which is revealed to be truly effective for delaying progress of aging. Every methods insisted on effect for delaying aging process, has its dark side. All we can do is just keeping ourself healthy until the time of death.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1357-1368
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• 2021

This paper presents thermal aging effect on fracture toughness properties of GTAW (gas tungsten arc welding) and SMAW (shielded metal arc welding) of 316L stainless steels, and investigates the applicability of the existing three thermal aging models for CASS (cast stainless steels). Thermal aging was carried out at 350 ℃ for up to 15,000h and at 400 ℃ up to 8,000h. After aging, tensile and fracture toughness tests using 0.5T C(T) specimens were carried out at room temperature and at 288 ℃. Comparing with the predictions using three (ANL, French and H3T) thermal aging models for CASS show that the predictions can be very non-conservative at operating temperature, and thus that the existing thermal aging models for CASS cannot be applied to the welded stainless steels.

• Molecules and Cells
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• v.45 no.11
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• pp.763-770
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• 2022

Caenorhabditis elegans has been used as a major model organism to identify genetic factors that regulate organismal aging and longevity. Insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) regulates aging in many species, ranging from nematodes to humans. C. elegans is a nonpathogenic genetic nematode model, which has been extensively utilized to identify molecular and cellular components that function in organismal aging and longevity. Here, we review the recent progress in the role of IIS in aging and longevity, which involves direct regulation of protein and RNA homeostasis, stress resistance, metabolism and the activities of the endocrine system. We also discuss recently identified genetic factors that interact with canonical IIS components to regulate aging and health span in C. elegans. We expect this review to provide valuable insights into understanding animal aging, which could eventually help develop anti-aging drugs for humans.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.210-222
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• 2015

The purpose of this study is to verify the mediation effect of social support in the influence of anxiety over aging of the elderly group on successful aging. The results of analyses are as follows: First, as anxiety over aging of the elderly group increased, the successful aging decreased. Second, in the relationship between anxiety over aging of the elderly group and social support, the social support decreased as anxiety over aging increased. Third, in the relationship between social support and successful aging, an increase of social support led to an increase in successful aging. Fourth, Old man in relationship to and successful aging of ageing in the social support mediated effect parts of their identified. Thus, this study suggests measures to decrease the anxiety over aging of the elderly group for the successful aging and proposals for the further studies in an aging society.

• Journal of Korean Public Health Nursing
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• v.29 no.1
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• pp.29-39
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• 2015

Purpose: The purpose of this study was to investigate the aging anxiety, factors of successful aging, and preparation for aging in early and late middle-aged people. Methods: The study subjects were 140 middle-aged people aged from 40 to 59. Data were collected using a self-administered questionnaire from August 16 to September 30, 2013. The collected data were analyzed with descriptive statistics, t-test, ${\chi}^2$-test and Pearson correlation coefficient using IBM SPSS 21.0 program. Results: Between early and late middle age, there were statistically significant differences in the subcategories of aging anxiety: fear of loss (t=2.93, p=.004), fear of old people (t=-2.33, p=.021), physical appearance (t=2.32, p=.022), and psychological concerns (t=2.04, p=.043). A statistically significant difference was found between two groups in one subscale of preparation for aging: physical preparation (t=-2.02, p=.045). In early midlife, significant associations were observed between preparation for aging and both aging anxiety (r=.56, p<.001) and factors of successful aging (r=.54, p<.001). In late midlife, preparation for aging and factors of successful aging showed positive correlation (r=.50, p<.001) Conclusion: Results of this study indicate that programs for successful transition to old age in middle-aged people should consider their aging anxiety level and preparation for aging at their stage of life.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.137-150
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• 2004

Aging effect of sands showed insignificant result in comparison with that of clay, so that it has not been studied so far. But, as penetration resistance increase has been observed with the lapse of time after deposition and disturbance, aging effect of sands has been actively investigated by field tests, and recently many researchers are performing not oかy field tests but also laboratory tests on sands, so aging effects of sands have been also examined by laboratory tests. In this study, to observe the aging effect of undrained static shear behavior for Nak-Dong River sand, undrained static triaxial tests were performed with changing relative density$(D_r)$, consolidation stress ratio$(K_c)$, and consolidation time. These tests showed that modulus within elastic section increased as consolidation time increased, and in addition, phase transformation point strength$(S_{PT})$ and critical stress ratio point strength $(S_{CSR})$ also increased. But pore water pressure ratio$(u/{p_c}')$ decreased as consolidation time increased, so with this various result, aging effect of static shear for sands can be observed as well.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.811-814
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• 2014

Bio-oil instability, or aging, is a significant problem for the long-term storage of fast pyrolysis oils. We investigated bio-oil aging at the molecular level using Fourier-transform ion cyclotron resonance mass spectrometry. Petroleomic analysis suggests that bio-oil aging is resulted from the oligomerization of phenolic lignin products whereas 'sugaric' cellulose/hemicellulose products have negligible effect.

• Macromolecular Research
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• v.16 no.6
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• pp.561-566
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• 2008

NR composites with different curing systems were aged thermally at 60, 70, 80, and $90^{\circ}C$ for 2-185 days in a convection oven, and the changes in the crosslink density were investigated as a function of the accelerated thermal aging. The overall crosslink densities increased with increasing aging time irrespective of the aging temperatures and curing systems. The changes in crosslink density were enhanced by increasing the aging temperature. The degree of the increased crosslink density was in the following order: "the conventional cure system > the semi-EV system > the EV system". For short term thermal aging, the change in crosslink density with the aging time was complicated, particularly for low temperature aging. The activation energies of the change in crosslink density with thermal aging using the conventional and semi-EV cure systems increased and then remained relatively constant with increasing aging time, whereas that of the specimen with an EV cure system tended to increase linearly. The experimental results were explained by the dissociation of the existing polysulfidic linkages and the formation of new cross links through the crosslinking-related chemicals remaining in the sample.