• BMB Reports
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• 제45권10호
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• pp.560-564
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• 2012

The role of peroxiredoxin (Prx) I as an erythrocyte antioxidant defense in red blood cells (RBCs) is controversial. Here we investigated the function of Prx I by using Prx $I^{-/-}$ and Prx I/$II^{-/-}$ mice. Prx $I^{-/-}$ mice exhibited a normal blood profile. However, Prx I/$II^{-/-}$ mice showed more significantly increased Heinz body formation as compared with Prx $II^{-/-}$ mice. The clearance rate of Heinz body-containing RBCs in Prx $I^{-/-}$ mice decreased significantly through the treatment of aniline hydrochloride (AH) compared with wild-type mice. Prx I deficiency decreased the phagocytic capacity of macrophage in clearing Heinz body-containing RBCs. Our data demonstrate that Prx I deficiency did not cause hemolytic anemia, but showed that further increased hemolytic anemia symptoms in Prx $II^{-/-}$ mice by attenuating phagocytic capacity of macrophage in oxidative stress damaged RBCs, suggesting a novel role of Prx I in phagocytosis of macrophage.

• 디지털융복합연구
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• 제17권11호
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• pp.339-347
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• 2019

이 연구는 중년여성의 노화불안에 사회적지지, 건강증진행위가 어떠한 영향을 미치는지 확인하기 위해 시도되었다. 연구대상자는 C시에 거주하는 40세에서 60세까지의 중년여성 160명이었다. 자료는 SPSS 23.0으로 기술통계, t-test, One-way ANOVA, 상관관계, 회귀분석을 하였다. 연구결과 (a) 노화불안은 사회적 지지(r=-.411, p<.001), 건강증진행위(r=-.614, p〈.001)와 음의 상관이 있었고, 사회적 지지(r=.429, p<.001)와 건강증진행위는 양의 상관이 있었다. (b) 중년여성의 노화불안에 영향을 미치는 변수는 건강증진행위의 하부요인인 영양(${\beta}=-0.329$, p<.001)과 스트레스 관리(${\beta}=-0.325$, p<.001), 폐경상태(${\beta}=0.214$, p<.001), 배우자지지(${\beta}=-0.160$, p=.011)였으며 이들의 설명력은 44.7% 이었다(F=33.12, p<.001). 이 연구에서 중년여성의 영양과 스트레스 관리, 배우자지지, 폐경 인식은 노화불안을 낮추는 것을 확인할 수 있었다. 추후 이들 변수를 포함하는 프로그램 개발과 그 효과를 확인할 연구가 필요하다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권4호
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• pp.154-160
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• 2005

We have investigated thermal properties showed by changing the content of carbon black which is the component parts of semiconductive shield in underground power transmission cable. Specimens were made of sheet with the nine of those for measurement. Density of specimens was measured by density meter, and then stress-strain of specimens was measured by TENSOMETER 2000. A speed of measurement was 200[mm/min], ranges of stress and strain were 400(Kgf/$cm^2$) and 600[$\%$]. In addition, tests of stress-strain were progressed by aging specimens at air oven. Finally surface profile was shown in order to looking for protrusion of specimens by using smoothness tester. Density was highly measured according to increasing the content of carbon black from this experimental result, and stress was decreased, while strain was increased according to increasing the content of carbon black. And stress-strain were decreased some after aging because of oxidation reaction of chemical defect. Lastly surface of specimens smoothed generally.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.402-403
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• 2009

Accelerated aging tests were conducted under laboratory conditions on two generator stator bars. Electrical stress is applied in No. 1 model stator bar. Electrical and thermal stresses are applied in No. 2 model stator bar. As aging times increased from 0 to 11460h, dissipation factor($tan{\delta}$) test was performed on No. 1 and No.2 model stator bars. The ${\Delta}tan{\delta}$ of No. 1 and No. 2 stator bars increased with increased in aging time.

• 한국세라믹학회지
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• 제24권5호
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• pp.477-483
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• 1987

Cr2O3 doped Pb(Zr0.525 Ti0.475)O3 piezoelectric ceramics were prepared from reagent grade oxide mixture, PbO, ZrO2, TiO2 and Cr2O3. Piezoelectric and aging properties of specimens were measured for various additions of Cr2O3. Generally, it has been known that aging rate decreased with Cr2O3 addition by stabilizing the domain wall. But hysteresis loops showed that the domain destabilization was occurred at high electric field (larger than 10KV/cm). In smaller additions of Cr2O3 (0-0.2mol%), aging rate increased and microcracks were created with increasing poling filed due to increasing internal stress. In larger additions of Cr2O3(0.4∼0.6mol%), aging rate decreased with increasing poling field.

• 전기학회논문지
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• 제58권7호
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• pp.1375-1379
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• 2009

Insulation tests have been performed on two generator stator bars under accelerated aging under a laboratory environment. Electrical stress was applied to stator bar No.1, and electrical and thermal stresses were applied to stator bar No.2. Nondestructive stator insulation tests including the ac current, dissipation factor($tan{\delta}$), and partial discharge tests have been performed on both bars as the bars were aged for 11460 hours. Experimental test results show that ${\Delta}I$, ${\Delta}tan{\delta}$, and partial discharge of No. 1 and No.2 stator bars increased with increased in aging time. It has been concluded from the test that the stator insulation of the two generators are in good condition.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.313-319
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• 2003

It is well known that ascorbic acid (VC) is an important factor for several physiological reactions. In the skin, VC works as an anti-aging agent due to removing of oxidative stress generated by UV irradiation and stimulation of collagen synthesis. Thus, developing more effective VC derivatives is an important issue in creating anti-aging skin care products. Our study succeeded to develop a novel ascorbic acid derivative, ascorbic acid tetra-2-hexyldecanoate (VC-IP), which is a lipid-soluble pro-VC. The purpose of this study was to indicate the effects of VC-IP as pro-VC and anti-aging agent. First, it was examined whether VC-IP is converted to VC in physiological conditions. Since VC was detected from the cell extracts treated with VC-IP, it was indicated that VC-IP is a pro- VC.(omiited)

• 한국전기전자재료학회논문지
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• 제16권12호
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• pp.1136-1141
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• 2003

The primary insulation materials used in an oil filled transformer are kraft paper, wood, porcelain and oil. Modern transformers use chemically treated paper to improve its tensile strength and resistance to aging caused by immersion in oil. But these insulation papers are mainly aged by thermal stress. Over the life time of the insulation paper and oil, it is exposed to high temperatures, oxygen and water. Its interaction with the steel of the tank and core plus the copper and aluminium of the windings will eventually cause the chemical properties of the oil to decay. High temperature have an effect on mechanical strength of cellulous paper used in the layer insulation. We made two aging cells in which insulation papers and mineral oil are conducted to test thermal properties. It is measured dielectric strength, number of acid, moisture, etc. of insulation paper and oil aged in the aging cells.

• 대한기계학회논문집
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• 제19권2호
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• pp.402-407
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• 1995

The effects of room temperature and strain aging treatment are discussed on the critical condition for the onset of growth of non-propagating cracks on 0.15% C low carbon steel, with special emphasis on the length of the critical non-propagating crack and on the crack opening displacement(COD) at the crack tip. It is found from the experimental analysis that room temperature and strain aging of a fatigue pre-cracked specimen introduced the closure of a crack tip of the pre-crack and the reduction of crack opening displacement at the wake of crack, together with an improvement in crack growth resistance of the microstructure. This may cause an increase in the endurance limit of the specimen, through the enhancement of effective stress for the onset of growth of the critical non-propagating crack.

• Biomolecules & Therapeutics
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• 제21권3호
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• pp.241-245
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• 2013

Aging is the single most important risk factor that increases susceptibility to many forms of diseases. As such, much effort has been put forward to elucidate the mechanisms behind the processes of aging and to discover novel compounds that retain anti-aging activities. Korean red ginseng has been used for a variety of medical purposes in eastern countries for several thousands of years. It has been shown that Korean red ginseng affects a number of biological activities including, but not limited to, anti-inflammatory, anti-oxidative and anti-diabetic pathways. However, few studies have been performed to evaluate its anti-aging effects with an in vivo system. Here Drosophila melanogaster as an in vivo model organism demonstrates that Korean red ginseng tonic extends lifespan, increases resistance to starvation stress and prevents weight gain. This data suggest that Korean red ginseng may regulate organisms' metabolism in favor of extending lifespan.