Sestrin 2 (SESN2) is a member of the sestrin family of stress-induced proteins that negatively regulate agingassociated biological processes. This study aims to investigate the role of SESN2 in regulating the differentiation potential and senescence of mesenchymal stem cells (MSCs) derived from young and elderly donors. Bulk RNA sequencing revealed a common decline in the SESN2 mRNA levels in MSCs from elderly individuals, which was confirmed via reverse transcription-polymerase chain reaction and western blot analyses. SESN2 knockdown in MSCs from young donors resulted in phenotypic changes similar to those in MSCs from elderly donors, including an enhanced expression of senescence and adipogenic markers and diminished expression of osteogenic markers. To confirm the effect of decreased SESN2 expression on osteogenic and adipogenic differentiation, we induced Sesn2 knockdown in mouse bone marrow-derived MSCs. Sesn2 knockdown suppressed the mRNA expression of osteogenic marker genes, alkaline phosphatase activity, and matrix mineralization. Furthermore, Sesn2 knockdown enhanced mRNA expression of the adipogenic marker genes and intracellular lipid accumulation. These results suggest that a decline in SESN2 expression during aging contributes to the shift of MSC differentiation from osteogenic to adipogenic lineage.

본 연구는 한국의 고령화 현황과 노인의 욕구 및 노인문제를 파악해 국가의 역할과 노인복지의 방향을 제안하고 있다. 이를 위해 인구변화와 고령화 추세에 대한 통계청 데이터, 보건복지부, 국가인권위원회의 자료 를 활용해 비교분석했다. 그 결과 한국의 고령화는 OECD국가의 평균 고 령화 속도보다 2-3배가 빠르다. 또한 2070년에 노년부양비는 100.6%로 증가하고, 노령화 지수는 620%로 급격하게 증가할 것으로 예상된다. 이 러한 현상으로 나타나는 노인빈곤 문제는 적극적인 소득보장정책의 추진 과 고령 친화적 주거환경 조성을 통해 해결해야 한다. 또한 노인차별과 고령자 학대를 예방하기 위한 홍보 및 학대행위에 대한 처벌의 강화가 필요하며, 신체적 노화를 보완할 수 있는 노인건강관리 지원이 필요하다. 마지막으로 노인 1인 가구에 대한 노인의료-돌봄의 연계망을 구축해야 한다.

Dynamic responses of nuclear power plant structure subjected to earthquake loads should be carefully investigated for safety. Because nuclear power plant structure are usually constructed by material of reinforced concrete, the aging deterioration of R.C. have no small effect on structural behavior of nuclear power plant structure. Therefore, aging deterioration of R.C. nuclear power plant structure should be considered for exact prediction of seismic responses of the structure. In this study, a machine learning model for seismic response prediction of nuclear power plant structure was developed by considering aging deterioration. The OPR-1000 was selected as an example structure for numerical simulation. The OPR-1000 was originally designated as the Korean Standard Nuclear Power Plant (KSNP), and was re-designated as the OPR-1000 in 2005 for foreign sales. 500 artificial ground motions were generated based on site characteristics of Korea. Elastic modulus, damping ratio, poisson’s ratio and density were selected to consider material property variation due to aging deterioration. Six machine learning algorithms such as, Decision Tree (DT), Random Forest (RF), Support Vector Machine (SVM), K-Nearest Neighbor (KNN), Artificial Neural Networks (ANN), eXtreme Gradient Boosting (XGBoost), were used t o construct seispic response prediction model. 13 intensity measures and 4 material properties were used input parameters of the training database. Performance evaluation was performed using metrics like root mean square error, mean square error, mean absolute error, and coefficient of determination. The optimization of hyperparameters was achieved through k-fold cross-validation and grid search techniques. The analysis results show that neural networks present good prediction performance considering aging deterioration.

Background: Post-ovulatory aging (POA) of oocytes is related to a decrease in the quality and quantity of oocytes caused by aging. Previous studies on the characteristics of POA have investigated injury to early embryonic developmental ability, but no information is available on its effects on mitochondrial fission and mitophagy-related responses. In this study, we aimed to elucidate the molecular mechanisms underlying mitochondrial fission and mitophagy in in vitro maturation (IVM) oocytes and a POA model based on RNA sequencing analysis. Methods: The POA model was obtained through an additional 24 h culture following the IVM of matured oocytes. NMN treatment was administered at a concentration of 25 μM during the oocyte culture process. We conducted MitoTracker staining and Western blot experiments to confirm changes in mitochondrial function between the IVM and POA groups. Additionally, comparative transcriptome analysis was performed to identify differentially expressed genes and associated changes in mitochondrial dynamics between porcine IVM and POA model oocytes. Results: In total, 32 common genes of apoptosis and 42 mitochondrial fission and function uniquely expressed genes were detected (≥ 1.5-fold change) in POA and porcine metaphase II oocytes, respectively. Functional analyses of mitochondrial fission, oxidative stress, mitophagy, autophagy, and cellular apoptosis were observed as the major changes in regulated biological processes for oocyte quality and maturation ability compared with the POA model. Additionally, we revealed that the activation of NAD+ by nicotinamide mononucleotide not only partly improved oocyte quality but also mitochondrial fission and mitophagy activation in the POA porcine model. Conclusions: In summary, our data indicate that mitochondrial fission and function play roles in controlling oxidative stress, mitophagy, and apoptosis during maturation in POA porcine oocytes. Additionally, we found that NAD+ biosynthesis is an important pathway that mediates the effects of DRP1-derived mitochondrial morphology, dynamic balance, and mitophagy in the POA model.

Machine learning is widely applied to various engineering fields. In structural engineering area, machine learning is generally used to predict structural responses of building structures. The aging deterioration of reinforced concrete structure affects its structural behavior. Therefore, the aging deterioration of R.C. structure should be consider to exactly predict seismic responses of the structure. In this study, the machine learning based seismic response prediction model was developed. To this end, four machine learning algorithms were employed and prediction performance of each algorithm was compared. A 3-story coupled shear wall structure was selected as an example structure for numerical simulation. Artificial ground motions were generated based on domestic site characteristics. Elastic modulus, damping ratio and density were changed to considering concrete degradation due to chloride penetration and carbonation, etc. Various intensity measures were used input parameters of the training database. Performance evaluation was performed using metrics like root mean square error, mean square error, mean absolute error, and coefficient of determination. The optimization of hyperparameters was achieved through k-fold cross-validation and grid search techniques. The analysis results show that neural networks and extreme gradient boosting algorithms present good prediction performance.

본 연구는 노인복지관 이용 여성노인의 사회적 자본과 성공적 노화의 관계 에서 여가활동 만족이 어떠한 매개적인 역할을 하는지 검증함으로써 여성노 인의 성공적 노화를 증진 시킬 수 있는 실천 방안을 모색하는 데 있다. 본 연구는 D지역 10개 노인복지관에서 여가 프로그램을 이용하는 여성노인을 대상으로 하였으며, 최종 자료분석에는 235부를 활용하였다. 본 연구결과, 첫째, 성공적 노화에 여성노인의 사회적 자본이 미치는 영향은 유의미한 것으 로 분석되었다. 노인복지관 이용 여성노인의 사회적 자본 수준이 높을수록 성 공적 노화가 높아진다는 것을 의미한다. 둘째, 여성노인의 여가활동 만족은 사회적 자본과 성공적 노화 간 관계에서 매개효과를 가지고 있음을 알 수 있 다. 이상의 연구결과를 바탕으로 노인복지관 이용 여성노인의 사회적 자본을 증진시키고 성공적 노화의 향상을 위한 시사점을 제시하였다.

Geopolymer, also known as alkali aluminum silicate, is used as a substitute for Portland cement, and it is also used as a binder because of its good adhesive properties and heat resistance. Since Davidovits developed Geopolymer matrix composites (GMCs) based on the binder properties of geopolymer, they have been utilized as flame exhaust ducts and aircraft fire protection materials. Geopolymer structures are formed through hydrolysis and dehydration reactions, and their physical properties can be influenced by reaction conditions such as concentration, reaction time, and temperature. The aim of this study is to examine the effects of silica size and aging time on the mechanical properties of composites. Commercial water glass and kaolin were used to synthesize geopolymers, and two types of silica powder were added to increase the silicon content. Using carbon fiber mats, a fiber-reinforced composite material was fabricated using the hand lay-up method. Spectroscopy was used to confirm polymerization, aging effects, and heat treatment, and composite materials were used to measure flexural strength. As a result, it was confirmed that the longer time aging and use of nano-sized silica particles were helpful in improving the mechanical properties of the geopolymer matrix composite.

본 연구는 북한이탈여성 노인의 성공적 노화 척도개발과 신뢰도, 타당 도를 검증하기 위한 연구이다. 연구자는 북한이탈여성 노인 20명을 심층 면담하여 구성요소를 설정했다. 포커스 그룹을 걸쳐 북한이탈여성 노인 의 성공적 노화 척도 예비문항을 개발했다. 이러한 작업을 수행한 후 문 항분석, 상관관계 분석, 탐색적 요인분석, 확인적 요인분석을 실시하여 척도의 신뢰도와 타당도를 검증했다. 연구결과 4요인 모델, 5요인 모델, 6요인 모델 모두 적합도 검증 결과 판정기준을 만족하는 것으로 분석했 다. 적합도 지수가 높게 나타난 6요인 모델을 최종적으로 선정했다. 연 구결과에 근거하여 북한이탈여성 노인에게 특징적으로 나타난 죽음인식, 자기성장, 모호한 상실 속에서의 가족 애착 등에 대한 논의를 했다.

목적: 본 연구는 국내 초고령자를 대상으로 삶의 만족도 및 우울과 라이프스타일신( 체활동, 식습관, 참여빈도, 참여다양성) 간의 상관관계를 확인하고, 삶의 만족도와 우울에 영향을 미치는 라이프스타일 요인을 분석 및 확인하고자 하였다. 연구방법: 본 연구의 독립변수는 라이프스타일 요인으로 신체활동, 규칙적 식습관, 참여빈도, 참여다양성이었으 며, 종속변인은 삶의 만족도와 우울이었다. 분석을 위해 SPSS를 이용해 상관관계분석 및 다중회귀분석을 실시하였다. 결과: 다중회귀분석을 통해 삶의 만족도에 영향을 미치는 요인으로는 참여빈도(t = 6.262, p < 0.001)와 규칙적 식습관(t = 4.627, p < 0.001)이 통계적 유의성을 가지는 것으로 확인되었으며, 우울에 영향을 미치는 요인으로는 참여빈도(t = 6.540, p < 0.001)와 규칙적 식습관(t = 4.061, p < 0.001)이 통계적 유의성을 가지는 것으로 확인되었다. 결론: 본 연구를 통하여 국내 초고령자의 삶의 만족도와 우울에 영향을 주는 라이프스타일 요인을 확인하였다. 따라서 본 연구 결과를 토대로 초고령자의 삶의 만족도와 우울 개선을 위해서는 라이프스타일을 기반으로 하는 다면적 중재 프로그램이 필요하다.

Black chestnut (BC) was obtained through aging of fresh chestnut (FC) at 80℃ for 15 days. Proximate and mineral compositions along with colors of FC and BC were evaluated. With aging, moisture contents decreased by 50%, whereas sugar contents, carbohydrate contents, and calories increased. Contents of minerals (Fe, P, Ca, Na, Mg, K) were significantly higher in FC than in BC, showing an order of Mg < Ca < P < K in both FC and BC. Using a Hunter color system, it was found that lightness (L), redness (a), and yellowness (b) values of FC were higher than those of BC. Antioxidant and cytotoxic activities of hot water and ethanol (50, 80, 100%) extracts prepared from FC and BC were evaluated. Extraction yields were lower with FC than with BC. Among water and ethanol extracts, water extract showed the highest DPPH radical scavenging activity for both FC and BC. IC50 values for ABTS+ radical scavenging activities increased after aging. Cytotoxicities of FC and BC extracts were similar to each other. They were different against various cell lines (3T3, HeLa, and Sarcoma-180). These results suggest that BC could be used as a new processed food using chestnut.

The Wolsong Nuclear Power Plant (NPP) operates an on-site spent fuel dry storage facility using concrete silo and vertical module systems. This facility must be safely maintained until the spent nuclear fuel (SNF) is transferred to an external interim or final disposal facility, aligning with national policies on spent nuclear fuel management. The concrete silo system, operational since 1992, requires an aging management review for its long-term operation and potential license renewal. This involves comparing aging management programs of different dry storage systems against the U.S. NRC’s guidelines for license renewal of spent nuclear fuel dry storage facilities and the U.S. DOE’s program for long-term storage. Based on this comparison, a specific aging management program for the silo system was developed. Furthermore, the facility’s current practices—periodic checks of surface dose rate, contamination, weld integrity, leakage, surface and groundwater, cumulative dose, and concrete structure—were evaluated for their suitability in managing the silo system’s aging. Based on this review, several improvements were proposed.

PURPOSES : There has been increasing interest in South Korea on warm-mix asphalt (WMA) and cold-mix asphalt (CMA) technologies that allow production of asphalt pavement mixtures at comparatively lower temperatures than those of hot-mix asphalt (HMA) for use in pavement engineering. This study aims to evaluate the feasibility of replacing HMA pavement with WMA pavement with the goal of reducing CO2 emissions associated with asphalt production for road construction. METHODS : Changes in the dynamic modulus characteristics of WMA and HMA according to short-term and long-term aging were evaluated. In addition, the effects of water damage were evaluated for short- and long-term aging stages. RESULTS : For WMA, in the process of mixing and short-term aging, early-age dynamic modulus decreased owing to low temperature and reduced short-term aging (STA) time. This could result in early damage to the asphalt pavement depending on the applied traffic load and environmental load. CONCLUSIONS : Mastercurves of the dynamic modulus were used for comparative analysis of WMA and HMA. Compared to the dynamic modulus after STA of HMA, the estimated aging time determined by experiments for WMA to achieve the required stiffness was more than 48 hours, which is equiva-lent to approximately 4 to 5 years real service life when converted. It is considered that further studies are needed for performance optimization to achieve early-age performance of the asphalt mixes.

이 연구의 목적은 중년기 성인의 노화불안이 인지적 유연성과 자기자비 의 수준을 감소시키는 순차매개효과를 통해서 심리적 안녕감에 부정적 영 향을 미친다는 가설을 경험적으로 검증하는 것이었다. 이를 위해, 40～64 세 연령의 중년기 성인 남녀 371명의 자기보고 자료를 수집하여 통계적으 로 분석하였다. 분석 결과, 중년기 성인의 노화불안은 인지적 유연성, 자기 자비, 심리적 안녕감과 모두 통계적으로 유의미한 부적 상관관계를 나타냈 다. 또한 중년기 성인의 노화불안이 심리적 안녕감에 미치는 부정적 영향 을 인지적 유연성과 자기자비가 순차적으로 매개하는 것으로 밝혀져서, 이 연구의 가설이 검증되었다. 이것은 노화불안을 경험하고 있는 중년기 성인 의 심리적 안녕감을 향상시키는 데 인지적 유연성을 회복하고 자기자비를 함양하는 개입전략이 유익할 수 있음을 시사하는 결과였다. 마지막으로 이 러한 결과의 임상적 함의 및 연구의 한계를 논의하였다.

AA1050/AA6061/AA1050 layered sheet was fabricated by cold roll-bonding process and subsequently T4 and T6 aging-treated. Two commercial AA1050 sheets of 1 mm thickness and one AA6061 sheet of 2 mm thickness were stacked up so that an AA6061 sheet was located between two AA1050 sheets. After surface treatments such as degreasing and wire brushing, they were then roll-bonded to a thickness of 2 mm by cold rolling. The roll-bonded Al sheets were then processed by natural aging (T4) and artificial aging (T6) treatments. The as roll-bonded Al sheets showed a typical deformation structure, where the grains are elongated in the rolling direction. However, after the T4 and T6 aging treatments, the Al sheets had a recrystallized structure consisting of coarse grains in both the AA5052 and AA6061 regions with different grain sizes in each. In addition, the sheets showed an inhomogeneous hardness distribution in the thickness direction, with higher hardness in AA6061 than in AA1050 after the T4 and T6 age treatments. The tensile strength of the T6-treated specimen was higher than that of the T4-treated one. However, the strength-ductility balance was much better in the T4-treated specimen than the T6-treated one. The tensile properties of the Al sheets fabricated in the present study were compared with those in a previous study.

우리나라는 초고령화 사회진입에 전세계적으로 보기드문 급속한 추세에 있다. 또한 코로나19로 인해 대 면적인 사회서비스 제한이 장기화된 상황에서 우리나라 서울보다 1.4배 넓은 소농·도시형인 포천시에 거주 하는 재가노인의 가장 우선시되는 욕구는 먼저 육체적으로 면역력 강화를 위한 영양섭취이고 다음으로는 사회관계를 통한 정신적인 스트레스 해소로 나타났다. 이에 포천시에 위치한 포천노인복지센터는 2004년부터 ‘재가노인지원서비스사업’을 수행하면서 집안에 서 적용 가능한 현관문 개폐와 노인 움직임 감지 등 IOT(Internet Of Things)를 실행하였다. 본 연구에서는 포천시에 거주하는 재가노인을 대상으로 경기도 특화사업인 ‘재가노인 건강기능강화를 위한 맞춤형영양지원사업’을 사회복지사 한명이 식재료와 조리방법을 직접 전달, 설명하는 ‘대면그룹 7명’ 과 수행했다. 그리고 자원봉사자와 재가노인이 일대일 재택대면매칭에 추가하여 ICT를 기반으로 원격화상 을 통해 조리사와 실시간 동시접속 하는 ‘비대면그룹 10명’으로 구분하였다. 8개월 동안 총17명의 대상자에게 음식요리와 섭취를 통해 ‘노인의 영양상태 간이조사’, ‘영양이 노인의 정서· 심리에 미치는 상관관계’ 설문조사와 인바디/혈압측정 등으로 정량적인 결과를 도출함으로써 재가노 인의 건강이 강화됨을 알 수 있었다.

‘지역사회 계속거주(AIP: Aging in Place)’는 자율적이고 독립적인 노년의 삶을 원하는 노인들의 욕구 와 노인시설 운영비용 부담을 줄이고자 하는 정부의 필요성이 부합되면서 인구 고령화에 대처하는 새로운 패러다임으로서 주목받으며 활발히 논의되고 있다. AIP에 관한 국내외의 다양한 연구들은 AIP가 노년기의 삶의 질에 긍정적인 영향을 미치고 있음을 주장하는데, 이는 노인이 자립적으로 생활할 수 있는 사회환경이 제공되었을 때 가능하다. 본 연구는 사람이 살아가는데 가장 기본적인 필수 의료와 임종기 완화의료 및 돌봄 등의 실태를 점검하고 AIP 관련 정책의 현행 법령과 제도를 살펴봄으로써, 국가와 지방정부의 책무는 무엇이며 향후 그 책무를 충실히 이행하기 위한 실효적 방안들은 무엇인지에 관하여 제언한다.

Numerous factors contribute to the deterioration of reinforced concrete structures. Elevated temperatures significantly alter the composition of the concrete ingredients, consequently diminishing the concrete's strength properties. With the escalation of global CO2 levels, the carbonation of concrete structures has emerged as a critical challenge, substantially affecting concrete durability research. Assessing and predicting concrete degradation due to thermal effects and carbonation are crucial yet intricate tasks. To address this, multiple prediction models for concrete carbonation and compressive strength under thermal impact have been developed. This study employs seven machine learning algorithms—specifically, multiple linear regression, decision trees, random forest, support vector machines, k-nearest neighbors, artificial neural networks, and extreme gradient boosting algorithms—to formulate predictive models for concrete carbonation and thermal impact. Two distinct datasets, derived from reported experimental studies, were utilized for training these predictive models. Performance evaluation relied on metrics like root mean square error, mean square error, mean absolute error, and coefficient of determination. The optimization of hyperparameters was achieved through k-fold cross-validation and grid search techniques. The analytical outcomes demonstrate that neural networks and extreme gradient boosting algorithms outshine the remaining five machine learning approaches, showcasing outstanding predictive performance for concrete carbonation and thermal effect modeling.