• Title/Summary/Keyword: Long-term Aging

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Effects of Long-Term Weight Training Exercise on Aging Heart in Rat (장기간 체중부하 운동훈련이 흰쥐 노화 심근에 미치는 영향)

  • 조현국;이영실;정형재;이용덕;박원학
    • Biomedical Science Letters
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    • v.4 no.2
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    • pp.87-101
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    • 1998
  • There is considerable interests in the effect of regular, vigorous exercise, in particular weight training as a possible measure in improving myocardial function. The present investigation aimed to examine possible effect of a long-term weight training program on the heart in aging rats. Male rats aged 3-,10-, and 20-month-old were divided at random into a control (sedentary) and the exercise group. The training group was exercised for 5 days a week by 1 RM of ten times with weight training apparatus. This investigation examined the changes of the heart muscle relative to histological, ultrastructural, cytochemical, and stereological studies in rats. Quantity of lipofuscin pigments was clearly increased in the weight training group of 15-month-old rats, and mitochondrial degeneration, vacuolization, and interstitial proliferation were observed as well. In the weight training group of 25-month-old rats the frequency as separated intercalated discs, fraying myofibrils and hypercontraction band increased in number compared with the same 15-mon1h-old group. From the experimental result of glucose-6-phosphatase activity, the enzyme activities decreased in the weight training group of 15-month-old rats, and more decreased in the same 25-month-old group. In stereological study, both 15- and 25-month-old training groups, mitochondrial and myofibrilar volume densities significantly decreased, whereas interstitial volume density significantly increased. From the experimental results obtained in the present study, it is suggested that long-term weight training exercise do not cause any significantly qualitative and quantitative ultrastructural change of the heart muscle in the young. On the contrary, long-term weight training exercise stress may actually induce degenerative changes in the heart muscle in the old age.

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Effect of Solar Radiation Aging on the Properties of Epoxy Polymers (에폭시 폴리머의 물성에 미치는 태양광 복사 노화의 영향)

  • Lee, Dong-Geon;Lee, Sang-Bong;Kim, Myung-June;Park, Jung-Sun;Lee, Soo-Yong;Kang, Tae-Yeob
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.9
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    • pp.769-774
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    • 2016
  • Epoxy polymer exposed to solar radiation on long-term is required to a long-term environmental test in order to ensure the reliability of operation performance. In this paper, the solar aging experiment is performed for 7, 14, 28, 56, and 84 cycles, using solar simulator designed according to MIL-STD-810. After the aging experiment, measuring RGB values and using the CIE1976 color space, each RGB decreasing rates and total color shift are calculated. In addition, using a universal testing machine, mechnical properties according to ASTM-D638 are measured. As a result, by increasing solar aging period, total color shift is increased, and the tensile strength and elongation are decreased, but the elastic modulus and the poisson's ratio are slightly changed.

Long-term administration of red ginseng non-saponin fraction rescues the loss of skeletal muscle mass and strength associated with aging in mice

  • Cho, Da-Eun;Choi, Gwang-Muk;Lee, Yong-Seok;Hong, Joon-Pyo;Yeom, Mijung;Lee, Bombi;Hahm, Dae-Hyun
    • Journal of Ginseng Research
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    • v.46 no.5
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    • pp.657-665
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    • 2022
  • Background: Sarcopenia is a new and emerging risk factor aggravating the quality of life of elderly population. Because Korean Red Ginseng (RG) is known to have a great effect on relieving fatigue and enhancing physical performance, it is invaluable to examine its potential as an anti-sarcopenic drug. Methods: Anti-sarcopenic effect of non-saponin fraction of Korean Red Ginseng (RGNS) was evaluated in C2C12 myoblasts treated with C2-ceramide to induce senescence phenotypes, and 22-month-old mice fed with chow diet containing 2% RGNS (w/w) for 4 further months. Results: The RGNS treatment significantly alleviated cellular senescence indicated by intracellular lipid accumulation, increased amount of lysosomal β-galactosidase, and reduced proliferative capacity in C2C12 myoblasts. This effect was not observed with saponin fraction. In an aged mouse, the 4-month-RGNS diet significantly improved aging-associated loss of muscle mass and strength, assessed by the weights of hindlimb skeletal muscles such as tibialis anterior (TA), extensor digitorum longus (EDL), gastrocnemius (GN) and soleus (SOL), and the cross-sectional area (CSA) of SOL muscle, and the behaviors in grip strength and hanging wire tests, respectively. During the same period, an aging-associated shift of fast-to slow-twitch muscle in SOL muscle was also retarded by the RGNS treatment. Conclusions: These findings suggested that the long-term diet of RGNS significantly prevented aging-associated muscle atrophy and reduced physical performance, and thus RGNS has a strong potential to be developed as a drug that prevents or improves sarcopenia.

Improvement of Management of Long-Term Care Facilities Through FGI (FGI를 통한 노인장기요양시설 운영 개선 방향에 관한 연구)

  • Park, Sung Won;Lee, Won Jae
    • The Journal of the Korea Contents Association
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    • v.19 no.1
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    • pp.587-597
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    • 2019
  • With the rapid aging of the nation's population and the increasing number of elderly people with difficulties in daily life, the elderly care system was implemented for social solidarity. Structural problems in the long-term care system that emerged after the introduction of the system are demanded, and the problem of functional readjustment between nursing hospitals and facilities is raised due to the lack of continuity of care for the elderly by institutional and salary types. In this study, we set up research problems related to personnel, staff, and services to address the problem and conducted FGI. Research has shown that the number of elderly and recognized people in the region, the number of elderly and elderly patients, needs to be reflected in long-term care demand, the direction of appropriate institutional and manpower supply policies, and the establishment of local government goals and plans to strengthen the long-care institutions. It was revealed that non-medical accident arbitration bodies are needed to apply the cost of food insurance, provide programs through links with relevant institutions, and manage the admission smoothly.

The Study of Leakage Current Distributions of Plymeric Insulators will Changing Environment (주위 환경 변화 따른 폴리머 절연재료의 표면 누설전류)

  • 이병성;한재홍;김주용;한상옥
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.88-91
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    • 2001
  • Our knowledge about their long-term performance in an outdoor environment is still very limited. The electrical stress caused the surface of these insulators to become degradation. In order to evaluate leakage current patterns caused by surface aging on polymeric insulators, we utilized the combined aging test facility and leakage current monitoring system. And we get the continuous leakage current values from each sample. After completing the 3000h combined aging cycle test, leakage current measurement were conducted for these samples and carried out harmonics analysis for its data.

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Evaluation of Ultimate Pressure Capacity of Prestressed Concrete Containment Building Considering Aging of Materials (재료의 경년상태를 고려한 PSC격납건물의 극한내압능력 평가)

  • 이상근;송영철;권용길;한상훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.805-810
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    • 2000
  • The purpose of this study is to predict long-term structural safety on the Yonggwang Unit 3 prestressed concrete containment building. The aging-related degradations of its main structural materials are investigated and the effects of the property variation of time-dependent materials on the structural behavior of containment building are also assessed through the analysis on the ultimate pressure capacity. The nonlinear finite element analyses for both the design criteria condition a the present aging condition are conducted to assess the present structural capacity of the containment building As a result, it is verified that the structural capacity of the Yonggwang Unit 3 containment building under the present aging condition is judged to be still rugged. n addition, the sensitivity of the ultimate pressrue capacity of containment building according to th degradation levels of the structural materials are assessed. Finally, it is showed that the sensitivity levels are in the order of the tendon, rebar and concrete in case of individual material degradations, and the tendon-rebar, tendon-concrete and rebar-concrete in case of coupled material degradations.

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Simulation Modeling for Human Resource Planning and Management: Revision of Promotion and Aging Chain Model (조직인력관리를 위한 예측 시뮬레이션: 승진 체인 모델의 개선)

  • Oh, Youngmin
    • Korean System Dynamics Review
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    • v.15 no.3
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    • pp.105-141
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    • 2014
  • Human Resource Planning and Management(HRPM) is to make organization efficiently and effectively. Based on Promotion and Aging Chain Model, a revised personnel management prediction simulation is established in terms of mid- and long-term organizational changes, annual budget and personnel strategy including a promotion, aging and laying off for the best personnel architecture in organization. Also, the model is possible to find a solution for increasing the organizational capacity. An empirical application to quasi-governmental organization proceeded to testing and validating the model.

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Aging Evaluation of Polymer Insulator Housing with UV Exposure (자외선 노출에 따른 폴리머애자 하우징의 열화특성평가)

  • 이병성;한재홍;김찬영;한용희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.214-217
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    • 1999
  • Polymeric composite insulators have been in use for outdoor insulation. However, our knowledge about their long-term performance in a outdoor environment is still very limited. Especially, these insulator are subjected to the environmental stress such as ultraviolet radiation. Hence, in this paper. the influence of UV radiation on the aging of the shed materials was evaluated. For the aging evaluation, these insulators studied by experiment methods such as contact angle measurement. oxidation induced time. SEM/EDX, FTRI-ATR, tracking test for the different insulator samples. With the increased UV exposure time, samples are shown to exhibit degradation comparable to those of new ones

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Thermal Aging Behaviors of Weather Resistant Rubber Composites of EPDM, IIR, and BIIR (EPDM, IIR, 그리고 BIIR 내후성 고무 복합체의 열노화 거동)

  • Choi, Sung-Seen;Kim, Jong-Chul
    • Elastomers and Composites
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    • v.47 no.2
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    • pp.148-155
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    • 2012
  • EPDM, IIR, and BIIR composites were thermally aged and the crosslink density changes were investigated. Crosslink densities of the EPDM composite increased with increasing the aging time and temperature, whereas those of IIR and BIIR composites for long-term aging at high temperatures tended to decrease. Activation energies for the crosslink density changes of the EPDM composite were higher than those of the BIIR one. The experimental results were explained with the number of allylic hydrogens, activation of the zinc complex, the steric hindrance effect, and oxidation of rubber chain.

Analysis of Degradation Characteristics for Oil-Paper Insulation using Tan Delta Measurement (Tan Delta 측정을 이용한 유침 절연지의 열화특성 분석)

  • Kim, Jeong-Tae;Kim, Woo-Bin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.9
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    • pp.1518-1523
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    • 2016
  • In this study, in order to understand the degradation characteristics of oil-paper insulation for power transformers and OF cables, tan delta was measured using cable model specimens with long-term accelerated thermal and electrical aging. In addition, to find out the degradation level due to the accelerated aging, tensile strengths of aged papers were measured. As a result, tan ${\delta}$ showed the characteristics of slight decrease at the first stage and then increase with the aging time, which could be analyzed due to the evaporation of remaining moisture and the change of aging rate with time. Also, the trend of tensile strengths with aging temperature and time was appeared to be exponentially decreased and by use of these data equivalent calculated lifetimes and accelerated aging factors were derived for each aging temperatures. After then, tan ${\delta}$ was analyzed with the equivalent operating years. For all different aging temperatures, the aged data were very well fit to the equivalent operating years and it is shown that tan ${\delta}$ was increased with the decrease of tensile strength.