• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1559-1563
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• 2004

The topoisomerase II poisoning effect of certain protoberberine alkaloids is associated with anti-cancer activity. Structure-activity relationships of protoberberine analogues substituted on the ring protons reveal that substitution at the C19 position is an important determinant of biological activity. In this study, the effects of substituent modification at the C19 position on the interaction of protoberberines with DNA are determined using UV and NMR spectroscopy. The line broadening effect on aliphatic resonances, chemical shift changes of the imino protons of HP14 upon berberine and berberrubine binding to HP14, and the rate of the exchange process between protoberberine analogs bound indicate that berberrubine binds HP14 more specifically than berberine. In addition, the free HP14 is altered by the substituent at the 19-position. UV spectra of berberrubine have shown a hypochromic effect together with a slight red shift, which are usually regarded as characteristics of DNA intercalation. These results are consistent with our previous report that the berberrubine is partially intercalated with HP14 with molar ratio 1 : 1, whereas a non-specific interaction is predominant between the berberine and HP14.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 춘계학술대회
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• pp.103-112
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• 2001

Bone homeostasis is maintained by a balance between activities of osteoblasts(bone forming cells) and osteoclasts (bone resorbing cells). The activities of these cells are closely regulated by multiple factors including hormones and cytokines. The cessation of estrogen at menopause disrupts the balanced regulation and is the main cause of osteoporosis in postmenopausal women. Recent molecular biological studies led to a discovery of tumor necrosis factor(TNF) and TNF receptor families genes that play critical roles in the regulation of osteoclast formation and function. RANKL (receptor activator of nuclear factor kappa B ligand; also called ODF, TRANCE, and OPGL) expressed on cells supporting osteoclast is essential for osteoclast differentiation, activation, and survival. RANK, the counter-receptor for RANKL, is expressed on progenitor and mature osteoclasts. The interaction between RANKL and RANK is requlated by a soluble decoy receptor OPG (osteoprotegerin). Gene knock out studies of these molecules showed profound effects on bone. These results prompted development of new strategies for treatment of bone diseases. Inhibition of osteoclast activity by blocking the RANKL-RANK interaction using OPG is being attempted. Research on the signaling pathways of RANK is also actively carried out. Screening natural products that inhibit the RANKL-RANK interaction or the activity of obteoclasts would be another effective means to a new drug target for bone resorbing diseases.

• Animal Bioscience
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• 제35권2호
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• pp.272-280
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• 2022

Objective: The aim of this study was to evaluate the effect of ageing and feeding strategies on the calpain protease system and meat quality traits in Braford steers. Methods: Thirty Braford steers were employed; 15 animals were supplemented with corn silage during finishing and 15 were kept only on pasture. Meat quality traits and calpain system protein activity were evaluated in longissimus thoracis et lumborum (LTL) steaks aged for 2, 7, 14, and 21 days. Results: Aged meat showed higher pH and calcium content, while Warner Bratzler shear force (WBSF) decreased to day 21. No interaction between ageing and diet was seen for quality traits. Steers finished with corn silage showed higher values of water holding capacity, WBSF and free calcium, and lower values of pH and cooking loss. Calpain and calpastatin activities decreased with ageing. Finishing steers on pasture produced higher values of calpains and lower values of calpastatin activities. The higher values of calpain 1 activity were observed in muscles aged 2 days from pasture finished animals, and the lower activity of the inhibitor in the 21 days aged samples of the same group. Conclusion: These results suggest a diet by ageing interaction in calpains and calpastatin and this interaction impact in Warner Bratzler Shear Force in Braford LTL muscle.

• 대한수학교육학회지:학교수학
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• 제6권2호
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• pp.153-179
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• 2004

본 연구에서는 모델링 과정의 활동을 세 가지 활동-지각적 활동, 인지적 활동, 메타인지적 활동-으로 구분하여 이 활동들의 상호작용으로 모델을 개발하는 과정을 중학교 학생들을 대상으로 사례연구 방법으로 조사하였다. 연구결과 학생들은 자신의 경험에 기반하여 과제상황을 이해하였고, 도구를 조작하는 지각적인 활동을 하면서 상황을 구조화하였다. 또한 지각적 활동에 기반하여 개발한 모델에 대해 사고하고 추론하는 인지적 활동을 재조직하면서 모델을 개발하였다. 아울러 메타인지적 활동을 통해 모델을 수정하고 정교화하여 일반화 가능한 모델을 개발하였다. 본 연구로부터 모델링 활동은 물리적 세계에서의 지각적인 활동과 추상적인 수학 활동을 연결함으로써 추상적인 수학 지식을 학생들이 이해하기 쉽게 지도할 수 있는 방법이라는 시사점을 얻을 수 있었다.

• 디자인학연구
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• 제18권2호
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• pp.273-282
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• 2005

본 연구는 유비쿼터스 컴퓨팅 환경구축에 활용하기 위한 상황인지 모델과 이를 활용한 멀티모달 인터랙션 디자인 프레임웍을 제안하였다. 먼저 상황인지 모델개발을 위해 사용자의 인터랙션 상황을 파악하는 방법과 수집된 상황의 의미를 추론하여 사용자 요구에 맞는 멀티모달 인터랙션 서비스를 제공하는 방법을 연구하였다. 또한 상황인지 모델(Context cube)을 활용한 멀티모달 인터랙션 디자인 프레임웍을 제안하였으며, 이 프레임웍의 활용성을 검증하는 사례연구를 수행하고, 개인화된 유비쿼터스 서비스 도출 및 이 서비스의 산업화 가능성을 제시하였다. 상황인지는 사용자의 기본 행위(Basic Activity), 공간에서의 사용자 위치 및 공간내의 기기 및 환경 요소, 시간 요소와 사용자의 일상적인 스케줄 정보 요소에 의해 파악할 수 있으며, 이러한 요소들을 종합하여 공간적인 개념의 상황인지 모델(Context Cube)을 개발함으로써, 구체적인 공간 모델 내에서의 다양하고 개인화 된 유비쿼터스 서비스의 제안이 가능하였다. 또한, 실제적인 사용자 시나리오에 의한 사례연구를 통해 개념 모델을 구축하는 과정 및 각 과정에서 요구되는 정보의 유형을 검증하고, 상황인지 모델에서의 구성요소의 내용과 배열 등을 정의함으로써 개념모델의 완성도를 높였으며, 상황인지 모델에서 표현되는 사용자의 인터랙션 특징을 바탕으로 멀티모달 인터랙션 디자인의 접근방법을 개발함으로서 이를 디자인 프레임웍으로 구체화할 수 있었다.

• 디지털융복합연구
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• 제4권2호
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• pp.75-85
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• 2006

The purpose of this study is to confirm whether the IT activity and organizational strategy makes a significant influence on the system performance. IT activity is defined as a system development, system operation and system management. Cost leadership and Differentiation were used as a strategic type. Field research was employed to empirically investigate the relationship among the variables. The finding of the study can be summarized as follows. IT activity and strategic type are not enough to explain the system performance.

• 한국간호교육학회지
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• 제15권1호
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• pp.81-88
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• 2009

Purpose: The purpose of this study was to identify the behavioral responses to a robot pet in pre-school children. Method: This activity for children was conducted for 5 days at a kindergarten and each session lasted 30 minutes. In order to measure children's temperament, Chun Heeyoung's Temperament Rating Scale was used. In addition, to investigate the behavioral responses to a robot pet, each session was videotaped. The videotape data was analyzed according to child-robot interaction. Result: On the average, subjects scored highest in emotionality and lowest in activity for the temperamental subscale. The videotape data revealed verbal, positive nonverbal, and negative nonverbal interaction. Conclusions: These results suggest that child-robot interaction reflects temperamental characteristics, therefore, to develop a nursing intervention program using a robot, it is necessary to consider individual differences and recreational factors to grab children's interest.

• BMB Reports
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• 제43권3호
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• pp.205-211
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• 2010

Sprouty (Spry) proteins have previously been suggested as negative regulators of the MAPK pathway through interaction with Raf-1. However, the molecular basis of this inhibition has not been elucidated. In this study, we used cells expressing FLAGtagged Raf-1 with point mutations at known phosphorylation sites to reveal that activation of Raf-1 mutants does not correlate with their degree of interaction with Spry2. The association of Raf-1 with Spry2 in intact cells was further corroborated by immunofluorescence colocalization. Additionally, there was no significant change observed in the strength of interaction between Raf-1 mutants and Spry2 after paclitaxel treatment despite differences in the activation levels of these mutants. Thus, our study provides the evidence that Spry2 does not directly regulate Raf-1 kinase activity, but instead acts as a scaffolding protein that assists interactions between Raf-1 kinase and its direct regulators.

• BMB Reports
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• 제28권4호
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• pp.331-335
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• 1995

Simian virus 40 (SV40) small-t antigen (small-t) has been known to regulate the activity of a cellular enzyme, protein phosphatase 2A (PP2A), composed of A. B, and C subunits, via binding to the A subunit In the study presented here, the stoichiometry of the binding of small-t to PP2A was determined to be 1: 1. It was also shown that small-t binds to the AC form of PP2A with a higher apparent affinity than it binds to the free A subunit. We also characterized the interaction of PP2A with wild-type and various mutant small-ts. A single-point mutant (Val134Met) and a double-point mutant (Trp147Gly;Leu152 Pro) of small-t exhibited 3-fold and 5-fold lower potencies in inhibiting PP2A activity. respectively. This suggests that the region around amino acids between 134 and 152 of small-t might be important in regulating the enzyme activity of PP2A.

• 가정과삶의질연구
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• 제22권3호
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• pp.1-9
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• 2004

The purposes of this study were (a) to compare the level of sense of community and community activity of the mixed-use residential buildings' residents with the expected residents for the mixed-use residential building, (b) and to investigate the degree of their needs of social interaction. For the survey the questionnaire from 176 residents of mixes-use residential building in Seoul, and 67 expected residents in Bundang Newtown are used. The analytical methods adopted in this study were frequency, percentage, chi-square test and t-test. It was found that the level of sense of community and the community activities of the mixed-use residential building' residents were higher than those of the expected residents. Their residents reported higher degree of participation on community activities than the expected residents. It was also found that the common space in their residential area promoted the residents' sense of community and community activity.