Muscle atrophy is characterized by a decrease in the mass of the muscle. With an increase in life expectancy and chronic illnesses, the incidence of muscle atrophy is increasing and the quality of life of patients is decreasing. Thus, reducing muscle atrophy is of high clinical and socio-economic importance. Mistletoe is a semi-parasitic plant that has been used as a traditional medicine in many countries to treat various human illnesses. It has been reported that Korean mistletoe extract (KME) has diverse biological functions including anti-tumor, anti-oxidant, anti-diabetic, anti-obesity properties, and extension of lifespan. Especially, we have recently reported that KME improves exercise endurance in mice, indicating its beneficial roles in enhancing the capacity of skeletal muscle. In this study, we investigated whether KME could activate the signaling pathway related to protein synthesis in a mouse model of muscle atrophy. Interestingly, KME efficiently activated the Akt/mTOR pathway, and Akt and mTOR are important signaling hub molecules for the acceleration of protein synthesis in muscle cells. In addition, KME also increased the activity of S6 kinase which is involved in the regulation of muscle cell size. Moreover, the ERK activity, required for transcription of ribosomal RNA for protein synthesis, was also enhanced in KME-treated mouse muscle. These data support the idea that KME increases muscle mass via increased protein synthesis. Our findings also suggest that Korean mistletoe might be a promising candidate for the development of functional foods that are beneficial for preventing muscle atrophy.

Bitter melon (Momordica charantia) is used in traditional herbal medicine in many Asian countries for the treatment of several diseases such as diabetes, eczema, night blindness, psoriasis, and rheumatism. Especially, most reports concerning the biological activities of bitter melon have focused on its effects on diabetes and hyperglycemia. Also, bitter melon is regarded as a longevity food, suggesting that it has several beneficial effects on anti-aging and the maintenance of a healthy state. Thus, we investigated whether bitter melon could increase the capacity of exercise in this study. Interestingly, bitter melon fruit extract activated AMP-activated protein kinase (AMPK), which is important for regulating glucose homeostasis, mitochondrial content and exercise capacity. In addition, bitter melon extract increased the expression of enzymes involved in fatty acid oxidation such as mitochondrial uncoupling protein 3 (UCP3), carnitine palmitoyl transferase 1b (CPT1b), and pyruvate dehydrogenase lipoamide kinase isozyme 4 (PDK4). Moreover, exercise tolerance was much more enhanced in bitter melon treated animals compared to the non-treated control group. These results suggest that bitter melon is a promising candidate for the development of functional foods beneficial for physical strength and the enhancement of exercise capacity.

본 연구에서는 겨우살이 열수 추출물인 미슬로 C의 안전성을 검토하고자 유전 독성 및 실험동물을 이용한 안전성 검사를 실시하였다. 미슬로 C의 미생물 돌연변이 실험을 S. typhimurium의 히스티딘 요구성 균주와 E. coli의 트립토판 요구성 균주를 이용하여 대사 활성계 적용 및 비적용 하에서 복귀돌연변이 시험을 실시한 바, 5,000 ㎍/plate의 처리 농도까지 복귀돌연변이 집락은 나타나지 않았다. ICR 마우스에게 500, 1,000 및 2,000 ㎎/㎏를 경구 투여하고, 골수세포를 수집하여 소핵을 측정한 결과, 정상마우스의 경우와 비교하여 유의한 소핵은 관찰되지 않았기에 미슬로 C는 유전독성을 유발하지 않는 것으로 판단되었다. 식품의약안전청의 의약품 등의 독성시험기준에 따라 암․수 SD 계열의 랫드에 시험물질을 0, 500, 1,000 및 2,000 ㎎/㎏/day의 용량으로 1회 경구 투여한 후, 14일간의 체중 변화 및 사망률을 조사한 결과, 대조군과 비교하여 유의한 체중 변화는 없었으며, LD50은 2,000 ㎎/㎏ 이상인 것으로 사료된다. 또한 0, 250, 500 및 1,000 ㎎/㎏/day의 용량으로 13주간 반복 투여하면서 실험동물의 일반증상, 체중변화, 혈액 및 혈액생화학적 변화, 부검소견, 조직학적인 변화를 관찰하였다. 시험기간 중 암․수 모든 군에서 시험물질 투여에 기인한 일반적인 증상 변화는 관찰되지 않았고, 시험물질의 반복 투여로 인한 사망 마우스 역시 관찰되지 않았다. 따라서 미슬로 C를 13주간의 랫드에 대한 13주 반복 경구투여 결과, 무독성량은 최소한 1,000 ㎎/㎏ 이하인 결과를 나타냈으며, 이 농도에서 독성을 유발하는 표적장기는 관찰되지 않았다.

대다수의 중·저층 RC 건물은 다양한 수평저항시스템으로 이루어져 있으며, 그 가운데에서도 취성적인 파괴성상을 나타내 는 전단파괴형 부재와 연성능력이 탁월한 휨파괴형 부재가 대표적이며, RC 건축물의 내진성능은 각 파괴모드를 나타내는 부재의 강도 및 변형특성의 조합으로 평가되어야한다. 본 연구에서는 전단 및 휨파괴형 부재가 혼합된 중·저층 RC 건물을 대상으로 반복가력실험을 수행하여 내진성능을 검토하였다.

본 연구에서는 비내진상세를 가지는 중⦁저층 R/C 건물의 1층 골조를 제작하여 무보강 실험체에 대한 구조실험을 실시하였다. 실험결과 실험체는 부재각 1.33%에서 전단파괴를 나타내어, 비내진상세를 가지는 R/C 건물의 내진성능에 관한 중요한 자료를 획득하였다. 본 연구에서는 간주형 좌굴방지 강재 슬릿댐퍼 시스템을 개발하였으며 내진보강효과를 검증하기 위하여 구조실험에 선행하여 상기 국내 비내진상세 RC 골조 실험결과를 기반으로 비선형해석을 실시하였다.

수직거동 마찰댐퍼 시스템의 내진보강공법의 유효성을 판단하기 위해 제진장치의 반복가력실험과 1980년대 비내진 상세를 가지는 R/C건축물을 대상으로 하는 실물 2층 골조를 제작하여 유사동적실험을 실시하였다. 실험결과 수직거동 마찰댐퍼 시스템으로 보강된 실험체는 동일 가속도(200 gal)에서 기준 실험체 대비 최대하중은 약 1.6배 증가하였고, 응답변위는 0.4배로 저감되어 본 연구에서 개발된 수직거동 마찰댐퍼 내진보강공법의 유효성이 검증되었다.

2016년 경주지진 이후로 국내에서도 본격적으로 건축물의 지진대책 강구가 시급한 시점에서 국내에 널리 보급되어 있는 R/C 건축 물의 효율적인 내진성능 평가 및 내진보강을 포함한 내진대책을 위한 기초적인 자료를 얻고자, 2016년 경주지진에서 지진피해를 받은 R/C 저 층 학교건축물(M학교)을 대상으로 지진피해도구분판정법을 이용하여 잔존내진성능과 지진피해정도를 평가함과 동시에, 부재수준의 비선형 동적해석을 수행하여 지진피해정도와의 상관관계를 검토하였다. 지진피해도구분판정에 의한 손상도-I로 분류된 기둥은 2개, 손상도-Ⅱ가 1 개, 손상도-III으로 분류된 기둥이 3개로 각각 평가되어, 최종적으로 평가한 내진성능잔존율(R)은 88.2%로 피해분류는 소규모 피해로 판정되 었으며, 또한 비선형동적해석 결과 1층 X방향의 최대응답을 나타낸 기둥의 휨변위는 0.7 mm, 전단변위는 6 mm로 전단균열은 발생하였지만, 전단파괴는 발생하지 않았다. 경주지진에서 지진피해를 입은 M학교의 지진피해가 1층의 X방향에 집중되어 있다는 사실, 휨균열보다는 전단 균열이 발생하였다는 사실을 고려한다면 본 연구에서 수행한 비선형동적해석 결과는 2016년 경주지진에서 지진피해를 받은 M학교의 지진피 해상황을 잘 반영하고 있다고 사료되며, 국내 기존 저층 R/C 건축물의 효율적인 내진성능 평가 및 내진보강을 포함한 내진대책을 위한 기초적 인 자료로서 활용가능하다고 사료된다.

The purpose of this study is to evaluate a RCS strengthening method for medium & low-rise R/C buildings using the nonlinear analyses of member-level. In this study, a three-story R/C buildings that represents a typical Korean school constructed in the 1980s was selected. Seismic capacities of the building before and after CFCC strengthening method are evaluated using the nonlinear static & dynamic analyses of member-level.

This paper proposes a new seismic retrofit methodology combined with glass fiber sheet (GFS) and non-compression X-brace system using carbon fiber (CFXB) for reinforced concrete buildings damaged in earthquakes. The result reveals that the retrofitting methodology(CR-1, CR-2) proposed in this study is more strengthen than non-retrofit methodology(CS-0) about maximum resisting force and maximum displacement.

The main purpose of this study is to evaluate the seismic capacity of R/C building having masonry spandrel-walls. The pseudo dynamic test was applied in order to investigate relationships of the short column effect between a pure R/C frame and a R/C frame having masonry spandrel-walls. At the same time, the non-linear dynamic analysis was carried out and compared test results.

The purpose of this study is to evaluate a RCS strengthening method for medium & low-rise R/C buildings using the nonlinear analyses of member levels. In this study, a three-story R/C buildings that represents a typical Korean school building constructed in the 1980s was selected. Seismic capacities of the building before and after strengthening with the RCS method are evaluated using the nonlinear static & dynamic analyses of member levels.

The purpose of this study is to evaluate seismic characteristics of medium and low-rise R/C buildings controlled by both shear and flexure. In this study, relationships between ultimate state and ductility demands of each lateral load-resisting-system were investigated based on laboratory tests.

The purpose of this paper is to verify the seismic strengthening effect of R/C buildings strengthened with the Carbon Fiber Composite Cable (CFCC) In this study, a three-story R/C building that constructed in the 1980s was selected, and its seismic performance before and after strengthening was evaluated based on the nonlinear dynamic analyses of members levels. The result indicated that the seismic strengthening effect of the proposed CFCC method was verified in terms of both strength and ductility demands, compared to the building before strengthening.

The purpose of this study is to verify a RCS strengthening method for Medium & Low-rise R/C buildings using the nonlinear analysis. In this study, a three-story R/C building that represents a typical Korean school constructed in the 1980s was selected. Seismic capacities of the building before and after RCS strengthening are evaluated based on the nonlinear static and dynamic analyses.

Many existing building in korea, constructed according to an out-date standard, were found to be inadequate to withstand major earthquake. Accordingly, significant research effort has been devoted to develop and evaluate different strengthening techniques to increase to seismic resistance of R/C structure. In our previous research[1], the galss fiber sheet and carbon fiber brace system for seismic strengthening was developed. In the study, a three-story R/C building that represent a typical Korean school constructed in 1980s was selected, and its seismic performance before and after strengthening was evaluated based on the seismic capacity evalution method.

The purpose of this paper is to verify the seismic strengthening effect of R/C buildings strengthened with the Carbon Fiber Composite Cable(CFCC). In this study, a three-story R/C building that represents a typical Korean school constructed in the 1980s was selected, and its seismic performance before and after strengthening was evaluated based on the nonlinear dynamic analyses. The result indicated that the seismic strengthening effect of the proposed CFCC method was verified in terms of both strength and ductility demands, compared to the building before strengthening