• 한국발생생물학회지:발생과생식
• /
• 제17권1호
• /
• pp.17-24
• /
• 2013

This study examined the expression of inhibitor of DNA-binding (Id) proteins and vascular endothelial growth factor (VEGF) in the ovary according to female age using a mice model as the first step in investigating the potential role of Ids and VEGF in ovarian aging. C57BL inbred female mice of three age groups (6-9, 14-16, and 23-26 weeks) were injected with 5 IU pregnant mare's serum gonadotropin (PMSG) in order to synchronize the estrus cycle. After 48 h, ovarian expression of Ids and VEGF was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR), western blot and immunohistochemistry. Ovarian apoptosis was examined by ovarian expression of Bcl-2 and Bcl-xL. Expression of Id-1 and VEGF was decreased with advancing female age, but not Id-2, Id-3, and Id-4. In particular, their expressions were significantly decreased in aged mice of 23-26 weeks compared with the young mice of 6-9 weeks (p < 0.05). In contrast, ovarian apoptosis was greatly increased in the aged mice compared to the young mice. This result suggests that Id-1 may have an implicated role in ovarian aging by associating with VEGF.

• 한국노년학
• /
• 제32권4호
• /
• pp.1181-1197
• /
• 2012

본 연구의 목적은 최근 외국에서 개발된 노화태도척도(AAQ)가 한국 노인에게 타당하게 적용가능한지를 검증하는 것이다. 이를 위해 서울, 경기, 충청권 노인 320명을 대상으로 3요인 24문항으로 구성된 노화태도척도(AAQ)에 대해 문항분석, 탐색적 요인분석, 수렴타당도 검증을 실시하였다. 분석 결과, 정규분포 가정에 위배되거나 요인계수가 낮은 3개의 문항이 삭제되어 총 21문항의 노화태도척도(AAQ-21)가 제시되었으며, 심리사회적 상실(psychosocial loss), 신체적 변화(physical change), 심리적 성장(psychological growth)의 3요인이 심리적 상실(psychological loss), 사회적 상실(social loss), 심신의 변화와 성장(change and growth in body and mind)의 3요인으로 재구성되었다. 21문항 노화태도척도의 내적신뢰도, 수렴타당도는 만족할 만한 수준이었다. 본 연구에서 제시한 21문항 노화태도척도(AAQ-21)는 다차원적 측면에서 노화태도를 측정할 뿐만 아니라 노화의 긍정적 측면 및 부정적 측면에 대한 태도까지 측정함으로써 노년학 연구자와 실무자들에게 과학적이고 체계적인 노화태도 측정방법을 제시할 것이다. 또한 노인복지현장 실무자는 물론 노인복지정책 개발자가 성공적 노화를 위한 프로그램과 정책마련을 위한 기초자료로 활용할 수 있을 것이다.

• 한국콘텐츠학회논문지
• /
• 제21권11호
• /
• pp.692-710
• /
• 2021

본 연구에서는 Brothers 등(2019)에 의해 개발된 노화인식 척도(Awareness of Age-Related Change Scale, AARC)의 한국판 타당화 작업을 수행하였다. 노인 당사자의 노화인식을 확인하기 위해 만 65세 이상의 노인 400명을 대상으로 연구를 수행하였다. 두 개의 표본(표본 1: 185명, 표본 2: 215명)을 대상으로 한국어로 번안한 노화인식 척도에 대해 탐색적 요인분석 및 확인적 요인분석을 시행하였다. 탐색적 요인분석에서는 손실 인식 요인은 건강 영역 손실 인식, 건강 외 영역 손실 인식의 두 가지 하위요인으로 구성되고, 이득 인식은 하위요인 없이 단일 요인으로 구성되는 것으로 나타났다. 확인적 요인분석 결과, 탐색적 요인분석 결과로 도출된 요인 구조가 경쟁모형보다 더 타당하였다. 또한 구성타당도를 검증하기 위해 노화태도와 상관분석, 정서경험에 대해 회귀분석을 수행하였다. 마지막으로 본 연구의 의의 및 활용방안을 논의하고, 한계 및 미래 연구를 위한 제언을 밝혔다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권3호
• /
• pp.515-524
• /
• 2020

Objective: Human mesenchymal stromal cells (MSCs) exhibit variable differentiation potential and can be divided accordingly into distinct subpopulations whose ratios vary with donor age. However, it is unknown whether the same is true in pigs. This study investigated MSC subpopulations in miniature pig and compared their characteristics in young (2 to 3 months) and adult (27 to 35 months) pigs. Methods: Osteogenic, chondrogenic, and adipogenic capacity of isolated MSCs was evaluated by von Kossa, Alcian blue, and oil red O staining, respectively. Cell surface antigen expression was determined by flow cytometry. Proliferative capacity was assessed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Expression of marker genes was detected by quantitative real-time polymerase chain reaction. Results: Porcine MSCs comprised cells with trilineage and bilineage differentiation potential (tMSCs and bMSCs, respectively) and non-differentiating stromal cells (NDSCs). The tMSC and bMSC fractions were smaller in adult than in young pigs (63.0% vs 71.2% and 11.6% vs 24.0%, respectively, p<0.05); NDSCs showed the opposite trend (25.4% vs 4.8%; p<0.05). Subpopulations showed no differences in morphology, cell surface antigen expression, or proliferative capacity, but octamer-binding transcription factor 4 (OCT4) expression was higher in tMSCs than in bMSCs and NDSCs (p<0.05), whereas sex determining region Y-box 2 (SOX2) expression was higher in tMSCs and bMSCs than in NDSCs (p<0.05). Aging had no effect on these trends. Conclusion: Porcine MSCs comprise distinct subpopulations that differ in their differentiation potential and OCT4 and SOX2 expression. Aging does not affect the characteristics of each subpopulation but alters their ratios.

• 한국전기전자재료학회논문지
• /
• 제32권6호
• /
• pp.490-495
• /
• 2019

This study performs the thermal aging of chlorosulfonated polyethylene (CSPE) for 807.36 and 1,614.48 hours at $110^{\circ}C$, which is equivalent to 40 and 80 years of aging at $50^{\circ}C$ in nuclear power plants, respectively. Flat-type CSPEs were soaked in seawater for five days and then dried for five days at room temperature. Furthermore, the soaked CSPEs were cleaned for 5 days with fresh water and dried for 1,100 days at room temperature. Through this process, the log IV of the CSPEs decreases, whereas the dissipation factor of the CSPEs increases as thermally accelerated aged years increase at the measured frequency. Although the phase degree of the response voltage versus excitation voltage of the CSPEs increases, that of the response current versus excitation voltage decreases with the thermally accelerated aging. The thermal conductivity of the CSPEs increases slightly, but the thermal diffusivity does not vary with the thermally accelerated aged year increase. The displacement of the compressive strength of the CSPEs decreases gradually as the thermally accelerated aged years increase.

• The Korean Journal of Physiology and Pharmacology
• /
• 제25권3호
• /
• pp.239-249
• /
• 2021

The present study explored the therapeutic potential of hydrogen sulfide (H2S) in restoring aging-induced loss of cardioprotective effect of remote ischemic preconditioning (RIPC) along with the involvement of signaling pathways. The left hind limb was subjected to four short cycles of ischemia and reperfusion (IR) in young and aged male rats to induce RIPC. The hearts were subjected to IR injury on the Langendorff apparatus after 24 h of RIPC. The measurement of lactate dehydrogenase, creatine kinase and cardiac troponin served to assess the myocardial injury. The levels of H2S, cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), nuclear factor erythroid 2-related factor 2 (Nrf2), and hypoxia-inducible factor (HIF-1α) were also measured. There was a decrease in cardioprotection in RIPC-subjected old rats in comparison to young rats along with a reduction in the myocardial levels of H2S, CBS, CSE, HIF-1α, and nuclear: cytoplasmic Nrf2 ratio. Supplementation with sodium hydrogen sulfide (NaHS, an H2S donor) and l-cysteine (H2S precursor) restored the cardioprotective actions of RIPC in old hearts. It increased the levels of H2S, HIF-1α, and Nrf2 ratio without affecting CBS and CSE. YC-1 (HIF-1α antagonist) abolished the effects of NaHS and l-cysteine in RIPC-subjected old rats by decreasing the Nrf2 ratio and HIF-1α levels, without altering H2S. The late phase of cardioprotection of RIPC involves an increase in the activity of H2S biosynthetic enzymes, which increases the levels of H2S to upregulate HIF-1α and Nrf2. H2S has the potential to restore aging-induced loss of cardioprotective effects of RIPC by upregulating HIF-1α/Nrf2 signaling.

• 한국산학기술학회논문지
• /
• 제14권8호
• /
• pp.3682-3690
• /
• 2013

본 연구는 미용학적 측면에서 중년여성을 대상으로 사회적 지지, 자기효능감, 주관적 건강 등 성공적 노화의 영향요인을 분석하고 검증하는 것이다. 서울과 경기 지역의 50~64세의 321명을 대상으로 설문조사하였으며 수집된 자료는 SPSS 18.0으로 분석하였고, 성공적 노화의 영향요인을 파악하기 위하여 다중회귀분석을 시행하였다. 그 결과를 요약하면 다음과 같다. 첫째, 성공적 노화에 가장 큰 영향을 미치는 요인은 사회적 지지였으며, 다음은 자기효능감, 주관적 건강의 순이었다. 둘째, 이들 변인들이 중년여성의 성공적 노화를 56.7% 설명하였다. 그러므로 중년여성들은 성공적인 노후를 위해 노화에 대한 능동적인 의식과 더불어 적극적인 태도를 취하는 것이 필요하며, 노년을 준비하는 예비 노년층에 맞는 실질적인 교육과 중재가 요구된다. 본 연구의 결과를 표면적 가치에 중점을 두고 있는 미용의 지식체계에 신체적, 심리적, 사회적 건강의 영역이 포함될 수 있도록 기초자료로 제공하고자 한다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제26권3호
• /
• pp.207-218
• /
• 2022

Aging in mammals, including humans, is accompanied by loss of bone and muscular function and mass, characterized by osteoporosis and sarcopenia. Although resistance exercise training (RET) is considered an effective intervention, its effect is blunted in some elderly individuals. Fibroblast growth factor (FGF) and its receptor, FGFR, can modulate bone and muscle quality during aging and physical performance. To elucidate this possibility, the FGFR inhibitor NVP-BGJ398 was administrated to C57BL/6n mice for 8 weeks with or without RET. Treatment with NVPBGJ398 decreased grip strength, muscular endurance, running capacity and bone quality in the mice. FGFR inhibition elevated bone resorption and relevant gene expression, indicating altered bone formation and resorption. RET attenuated tibial bone resorption, accompanied by changes in the expression of relevant genes. However, RET did not overcome the detrimental effect of NVP-BGJ398 on muscular function. Taken together, these findings provide evidence that FGFR signaling may have a potential role in the maintenance of physical performance and quality of bone and muscles.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제7권4호
• /
• pp.163-172
• /
• 2007

Phenomenon, such as hardening, cracking or breaking etc.. of PVC tape for wiring harness by aging were detected on driven automobile in field. Hardening or cracking of PVC tape were confirmed decline of elongation by surrounding stress. The accelerated heat aging test was carried out applying temperature most important factor of aging, and then deduced an equation of useful life using arrhenius model. Prediction method of useful life of PVC tape was developed using miner rule calculating damage value by thermal energy classified temperature by matching deduced equation of useful life and measured temperature value on driven automobile in field.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
• /
• pp.289-292
• /
• 2004

반도체 소자의 파괴 원인으로는 주로 열, 전압, 전류, 진동 및 압력 등이 있다. 이 중에서 전압과 열을 스트레스 인자로 적용하여 가속열화 시험을 진행하였다. 전압 및 열에 의한 소자의 열화정도를 파악하기 위해 현재 상용화되어 있는 Phase Control Thyristor 중 $V_{DRM}\;=\;1500V,\;V_{BRM}\;=\;1500V, \;T_{HS}\;=\;-40{\sim}125^{\circ}C$ 정도의 사양을 가지는 소자를 사용하였다. 열화에 의한 여러 가지 변동특성 중에서 소자의 순방향 및 역방향 항복특성의 변화와 누설전류의 변화에 대해 실험을 통해 알아보았다.