• Food Science of Animal Resources
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• v.36 no.2
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• pp.159-169
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• 2016

Animal muscles are stored for specific period (aging) at refrigerated temperatures, during and after which the living muscles start to convert into meat and thus, attain certain superior properties in the final product. Proteolysis, lipolysis, and oxidation are the major biochemical processes involved during the postmortem aging of meat that affect the tenderness, juiciness, and flavor, as well as sometimes may introduce certain undesirable traits. This review analyzes the role of pre- and post-mortem factors that are important for aging and their effect on the chemical and physical changes in the “dry- and wet-aged meat.” Thus, if the meat processing manufacturers optimize the effects of aging for specific muscles, the palatability, color, and the shelf life of the aged meat products could be significantly enhanced.

• Nutrition Research and Practice
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• v.17 no.4
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• pp.597-615
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• 2023

Healthy aging can be defined as an extended lifespan and health span. Nutrition has been regarded as an important factor in healthy aging, because nutrients, bioactive food components, and diets have demonstrated beneficial effects on aging hallmarks such as oxidative stress, mitochondrial function, apoptosis and autophagy, genomic stability, and immune function. Nutrition also plays a role in epigenetic regulation of gene expression, and DNA methylation is the most extensively investigated epigenetic phenomenon in aging. Interestingly, age-associated DNA methylation can be modulated by one-carbon metabolism or inhibition of DNA methyltransferases. One-carbon metabolism ultimately controls the balance between the universal methyl donor S-adenosylmethionine and the methyltransferase inhibitor S-adenosylhomocysteine. Water-soluble B-vitamins such as folate, vitamin B6, and vitamin B12 serve as coenzymes for multiple steps in one-carbon metabolism, whereas methionine, choline, betaine, and serine act as methyl donors. Thus, these one-carbon nutrients can modify age-associated DNA methylation and subsequently alter the age-associated physiologic and pathologic processes. We cannot elude aging per se but we may at least change age-associated DNA methylation, which could mitigate age-associated diseases and disorders.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.1-6
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• 1996

Cellulose fiber reinforced cement composites manufactured by the slurry-dewatering process have found broad applications in thin cement products as replacement for asbestos cement. This paper focuses on the durability characteristics of these composites under different aging conditions. The effects of wetting-drying and freezing-thaw cycles, carbonation, and exposure to hot and humid environments on the structure and properties of cellulose fiber-cement composites were investigated. The predominant mechanisms of aging in the composites were identified through investigation of structure-property relationships. Measures to control these aging mechanisms were diversed and evaluated. Refined cellulose fiber-cement composites are shown to possess excellent durability characteristics under the effects of various aging processes.

• BMB Reports
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• v.50 no.4
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• pp.164-174
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• 2017

Mitochondria are cytosolic organelles essential for generating energy and maintaining cell homeostasis. Despite their critical function, the handful of proteins expressed by the mitochondrial genome is insufficient to maintain mitochondrial structure or activity. Accordingly, mitochondrial metabolism is fully dependent on factors encoded by the nuclear DNA, including many proteins synthesized in the cytosol and imported into mitochondria via established mechanisms. However, there is growing evidence that mammalian mitochondria can also import cytosolic noncoding RNA via poorly understood processes. Here, we summarize our knowledge of mitochondrial RNA, discuss recent progress in understanding the molecular mechanisms and functional impact of RNA import into mitochondria, and identify rising challenges and opportunities in this rapidly evolving field.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.104-110
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• 2008

Poly(allylamine) hydrochloride is a weak cationic polyelectrolyte that exhibits different aggregation properties at different solution pH values and aging times. Specifically, after several days aging in a pH 3 buffer, less than 1 mg/mL poly(allylamine) hydrochloride became turbid, and the hydrodynamic radius increased with a single diffusion mode. However, the hydrodynamic radius did not change at high concentrations. The dynamic processes of polymer aggregations at different pH values were verified by a light scattering and zeta-potential apparatus. The major interaction was caused by the capturing of counterions by the polyelectrolyte, which generates electrostatic, hydrophobic and cation-p interactions.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.65-68
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• 1997

In this study, we investigate the difference between natural aggregate and electric arc furnace (EAF) slag one in order to use EAF slag aggregate as coarse aggregate in concrete. We find the physical and chemical properties of EAF slag aggregate according to the different aging processes. We consider the properties of the concrete made with EAF slag aggregate on these bases.

• 한국노년학
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• v.38 no.3
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• pp.767-782
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• 2018

Academic research of the elderly psychology flourishes in an aging society. The basic concern of both psycho-gerontology dealing with psychological processes of aging and geronto-psychology dealing with psychology of the elderly is with the maintenance of high quality of life and well-being. Given this context, the present study examined research trends of 91 depression and suicide studies and 31 aging and successful aging studies, and compared the trends with those identified in studies published within the first 30 years. It was found that a majority of studies are concerned with the direct or mediating effects of depression on suicide and everyday life, risk factors influencing depression, perceptions of aging and factors influencing those perceptions, and successful aging and factors influencing successful aging. Further, the number of studies of these topics is greater than that of studies published within the first 30 years. The findings were discussed in the context of heightening the quality of life of the older adults.

• Biomolecules & Therapeutics
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• v.23 no.6
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• pp.557-563
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• 2015

Skin aging is the most readily observable process involved in human aging. Ultraviolet B (UVB) radiation causes photo-oxidation via generation of reactive oxygen species (ROS), thereby damaging the nucleus and cytoplasm of skin cells and ultimately leading to cell death. Recent studies have shown that high levels of solar UVB irradiation induce the synthesis of matrix metalloproteinases (MMPs) in skin fibroblasts, causing photo-aging and tumor progression. The MMP family is involved in the breakdown of extracellular matrix in normal physiological processes such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes such as arthritis and metastasis. We investigated the effect of diphlorethohydroxycarmalol (DPHC) against damage induced by UVB radiation in human skin keratinocytes. In UVB-irradiated cells, DPHC significantly reduced expression of MMP mRNA and protein, as well as activation of MMPs. Furthermore, DPHC reduced phosphorylation of ERK and JNK, which act upstream of c-Fos and c-Jun, respectively; consequently, DPHC inhibited the expression of c-Fos and c-Jun, which are key components of activator protein-1 (AP-1, up-regulator of MMPs). Additionally, DPHC abolished the DNA-binding activity of AP-1, and thereby prevented AP-1-mediated transcriptional activation. These data demonstrate that by inactivating ERK and JNK, DPHC inhibits induction of MMPs triggered by UVB radiation.

• Genomics & Informatics
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• v.21 no.2
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• pp.23.1-23.9
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• 2023

The mammalian sirtuin family, consisting of SIRT1-SIRT7, plays a vital role in various biological processes, including cancer, diabetes, neurodegeneration, cardiovascular disease, cellular metabolism, and cellular homeostasis maintenance. Due to their involvement in these biological processes, modulating sirtuin activity seems promising to impact immuneand aging-related diseases, as well as cancer pathways. However, more understanding is required regarding the safety and efficacy of sirtuin-targeted therapies due to the complex regulatory mechanisms that govern their activity, particularly in the context of multiple targets. In this study, the interaction landscape of the sirtuin family was analyzed using a systems biology approach. A sirtuin protein-protein interaction network was built using the Cytoscape platform and analyzed using the NetworkAnalyzer and stringApp plugins. The result revealed the sirtuin family's association with numerous proteins that play diverse roles, suggesting a complex interplay between sirtuins and other proteins. Based on network topological and functional analysis, SIRT1 was identified as the most prominent among sirtuin family members, demonstrating that 25 of its protein partners are involved in cancer, 22 in innate immune response, and 29 in aging, with some being linked to a combination of two or more pathways. This study lays the foundation for the development of novel therapies that can target sirtuins with precision and efficacy. By illustrating the various interactions among the proteins in the sirtuin family, we have revealed the multifaceted roles of SIRT1 and provided a framework for their possible roles to be precisely understood, manipulated, and translated into therapeutics in the future.

• Journal of the Korean Ceramic Society
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• v.48 no.4
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• pp.263-268
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• 2011

ZnO hexagonal rods grown in aqueous solution can be changed into a tubular shape by two-step aging in the course of the growing process. In the first step, hexagonal ZnO rods is grown by aging at $90^{\circ}C$ under a highly supersaturated aqueous solution giving rise to a fast precipitation rate. Meanwhile, during the second step aging at $60^{\circ}C$ in the same aqueous solution, the hexagonal polar face (001) having higher surface energy than (010) side planes dissolves to minimize surface energy. Hence the flat (001) face changes to a craterlike face and the hexagonal rod length of ZnO decreases at an initial-stage of this step aging. The formation of the (101) wedge-type faces is ascribed to the resultant of competitive reactions between the dissolution of polar face minimizing the surface energy which is a dominant reaction at the initial stage and the precipitation reaction dissipating supersaturation. At a later stage of the second-step the reaction rates of these two processes in the aqueous solution become similar and the overall reaction is terminated.