• BMB Reports
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• v.35 no.1
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• pp.87-93
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• 2002

Neural cell survival is an essential concern in the aging brain and many diseases of the central nervous system. Neural transplantation of the stem cells are already applied to clinical trials for many degenerative neurological diseases, including Huntington's disease, Parkinson's disease, and strokes. A critical problem of the neural transplantation is how to reduce their apoptosis and improve cell survival. Neurotrophic factors generally contribute as extrinsic cues to promote cell survival of specific neurons in the developing mammalian brains, but the survival factor for neural stem cell is poorly defined. To understand the mechanism controlling stem cell death and improve cell survival of the transplanted stem cells, we investigated the effect of plausible neurotrophic factors on stem cell survival. The neural stem cell, HiB5, when treated with PDGF prior to transplantation, survived better than cells without PDGF. The resulting survival rate was two fold for four weeks and up to three fold for twelve weeks. When transplanted into dorsal hippocampus, they migrated along hippocampal alveus and integrated into pyramidal cell layers and dentate granule cell layers in an inside out sequence, which is perhaps the endogenous pathway that is similar to that in embryonic neurogenesis. Promotion of the long term-survival and differentiation of the transplanted neural precursors by PDGF may facilitate regeneration in the aging adult brain and probably in the injury sites of the brain.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.514-519
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• 2001

Converter has been slag produced 10 million tons per year in Japan. It is a steel making by product produced in the same way as the blast-furnace slag. Though blast-furnace slag is being used effectively as a concrete admixture, the converter stag has never been used effectively because of the expansion action of contained free lime and iron oxide. This is an important environmental problem in the steel industry. Beta-2CaOSiO$_2$(beta-C$_2$S) is contained 40 percent in converter slag, therefore it is very promising as a concrete admixture. We proposed an accelerated aging processes capable of stabilizing the converter slag in a short time. The converter slag is dipped into alkali aqueous solution after heating at low temperature. It was subsequently ground to a grain size of 75 ${\mu}{\textrm}{m}$ , inner 30 percent of OPC. The properties of mortar and concrete using the blended cement were determined. As a result, it has become apparent that the expansion was reduced and long term compressive strength was increased while that at early ages was not so remarkable. The hydration exotherm rate was lower than that of the OPC.

• Journal of Life Science
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• v.9 no.5
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• pp.548-555
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• 1999

Long-term effects of Ganoderma lucidum (GL) on memory and oxidative stress of senescence-accelerated mice (SAM) were investigated. Senescence-resistant (R1) and prone (P8) strains of SAM were fed GL diets, premixed with low (20 mg/kg/day, T1) or high (200 mg/kg/day, T2) levels of GL powder for 9 months starting from young (3 months of age) or for 5 months starting from old (7 months of age). After the final feeding at 12 months of age, all animals were subjected to passive avoidance test for the evaluation of memory function. In addition, the changes in hepatic thiobarbituric acid-reactive substance (TBARS) and glutathione were analyzed. SAMP8 fed GL diets from old age (7 months) exhibited the improvement of memory, although GL rather inhibited the memory function of both SAMR1 and SAMP8 mice fed diets from young (3 months of age). Hepatic TBARS contents were decreased in SAMP8 fed high GL diet for 9 months and in SAMR1 fed low GL diet for 5 months. Hepatic glutathione content was also remarkably increased in SAMR1 following both feeding periods, and less extent in SAMP8 fed diet for 5 months of age. Taken together, it is proposed that GL extracts may play an anti-aging role through antioxidant action, and thereby may improve the senescence-related memory dysfunction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1735-1740
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• 2010

The propellant KM10, a single propellant manufactured nitrocellulose, is known to cause natural degradation phenomena at long term storage. The self-life was estimated using generally used high temperature acceleration aging tests to analyze the content of stabilizer and using the Arrhenius equation & Berthelot equation to calculate reaction rate constants. According to the result of this study, self-life of propellant KM10 using the Arrhenius equation & Berthelot equation appear significantly different as 43.73, 16.53years and when compared with the paper of E. R. Bixon, self-life of propellant KM10 predicted using the Arrhenius equation was reasonably determined.

• Journal of Applied Reliability
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• v.7 no.1
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• pp.31-43
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• 2007

The function of O-ring seals is to prevent leakage during the service life of the components in which they are installed. The life prediction of O-ring is very important at various industry fields. Generally, to evaluated the long-term performance of O-ring in severe environments has applied a life prediction technique based on accelerated life test (ALT). In this work, Accelerated thermal aging test(l20, 130, 140, $150^{\circ}C$) of O-ring was applied for life prediction of O-ring. The property changes after thermal aging test was measured using TGA, DSC, FT - IR, Video Microscope and SEM. Shape parameter and life prediction were obtained using MINITAB program.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.59-65
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• 2018

During natural aging, hydroxyl-terminated polybutadiene(HTPB) propellant undergoes a series of slow physico-chemical degradation reactions. By using accelerated ageing conditions it is possible to simulate the material behavior at different time-temperatures focusing on in-service conditions. Aging behaviors of HTPB propellant are investigated using HFC(heat flow calorimeter), a universal technique for measuring the rate of slow chemical and physical processes in long-term storage.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.290-301
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• 2022

Increasing life expectancy leads to a rise in the prevalence of aging-related mental diseases and a concomitant increase in the financial and societal pressures related to their prevention and management. This issue is attracting increasing attention from researchers. Therefore, this study aimed to determine whether a healing program in a forest environment is effective for improving cognitive function, depression, anxiety, and stress in elderly people. A nonequivalent control group pretest-posttest design was used. The experimental group consisted of 18 males and females aged 60 to 80 years who participated in a forest healing program for seven days, while the comparison group comprised 10 people with similar demographics. For the process of data analysis, this study performed a cross-analysis to determine the homogeneity of the data and carried out the Wilcoxon signed-rank test, a nonparametric statistical test, to verify the significance of each group. Participation in the forest healing program led to a significant improve-ment in cognitive function (p=0.030). The levels of depression decreased, but this result was not statistically significant. The levels of anxiety decreased significantly (p=0.004). The mean cortisol score, a measurement of stress, decreased, but it was not statistically significant. These findings confirmed the effectiveness of this program for improving certain mental conditions of elderly people, and affirmed that the use of long-term forest healing programs can be expected to alleviate national pressures created by aging societies.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3898-3906
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• 2023

The paper notes that the most common way of handling spent nuclear fuel (SNF) of power reactors is its temporary long-term dry storage. At the same time, the operation of the dry spent fuel storage facilities almost never use the modern capabilities of information systems in safety control and collecting information for the next studies under implementation of aging management programs. The author proposes a structure of an information system that can be implemented in a dry spent fuel storage facility with ventilated storage containers. To control the thermal component of spent fuel storage safety, a database structure has been developed, which contains 5 tables. An algorithm for monitoring the thermal state of spent fuel was created for the proposed information system, which is based on the comparison of measured and forecast values of the safety criterion, in which the level of heating the ventilation air temperature was chosen. Predictive values of the safety criterion are obtained on the basis of previously published studies. The proposed algorithm is an implementation of the information function of the system. The proposed information system can be used for effective thermal monitoring and collecting information for the next studies under the implementation of aging management programs for spent fuel storage equipment, permanent control of spent fuel storage safety, staff training, etc.

• Journal of Ginseng Research
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• v.48 no.3
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• pp.286-297
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• 2024

Brain plasticity refers to the brain's ability to modify its structure, accompanied by its functional changes. It is influenced by learning, experiences, and dietary factors, even in later life. Accumulated researches have indicated that ginseng may protect the brain and enhance its function in pathological conditions. There is a compelling need for a more comprehensive understanding of ginseng's role in the physiological condition because many individuals without specific diseases seek to improve their health by incorporating ginseng into their routines. This review aims to deepen our understanding of how ginseng affects brain plasticity of people undergoing normal aging process. We provided a summary of studies that reported the impact of ginseng on brain plasticity and related factors in human clinical studies. Furthermore, we explored researches focused on the molecular mechanisms underpinning the influence of ginseng on brain plasticity and factors contributing to brain plasticity. Evidences indicate that ginseng has the potential to enhance brain plasticity in the context of normal aging by mediating both central and peripheral systems, thereby expecting to improve age-related declines in brain function. Moreover, given modern western diet can damage neuroplasticity in the long term, ginseng can be a beneficial supplement for better brain health.

• Journal of Oriental Neuropsychiatry
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• v.13 no.1
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• pp.19-37
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• 2002

Objectives : This study sought to define autonomic functional difference on heart rate variability between headache patients and normal subjects Methods : We determined, heart rate variability of 52 headache patients and 30 normal subjects by means of three time domain measures: Mean PR(mean pulse rate), SDNN(standard deviation of all normal R-R intervals), RMSSD(the square root of the mean of sum of the squares of differences between adjacent normal R-R intervals), and five frequency domain measures: TP(total power), VLF(very low frequency), LF(low frequency), HF(high frequency). Results : 1) RMSSD, TP, HF, HF Norm of HRV decreased with aging and LF Norm, LF/HF increased with aging in headache patients. 2) There was no significant differences between migraine and tention headache in any standard index of HRV, whereas, HRV of total headache patients were smaller than those of normal subjects. 3) In the gender comparison, SDNN, RMSSD, HF of tention headache patients were the smallest and then migraine patients, normal subjects in order with man, whereas, LF Norm, LF/HF of normal subjects were the smallest with man. RMSSD of migraine patients were the smallest and then tention headache patients, normal subjects in order with women. 4) In the term of history of headache patients, SDNN, RMSSD were getting lower as long term. 5) There was no significant differences of HRV in physical symptom of headache patients. Conclusions : All of these results show that standard index of HRV of headache patients were significantly different with normal subjects.