• 제목/요약/키워드: Competitive interactions

검색결과 91건 처리시간 0.027초

Alpha-alkylcysteines as Inhibitors for Carboxypeptidase A. Synthesis, Evaluation, and Implication for Inhibitor Design Strategy

  • Lee, Hyun-Soo;Kim, Dong-H.
    • Bulletin of the Korean Chemical Society
    • /
    • 제23권4호
    • /
    • pp.593-597
    • /
    • 2002
  • (R,S)- and (R)-2-Benzylcysteine (1) and (R,S)-2-phenethylcysteine (2) were synthesized and evaluated as inhibitors for carboxypeptidase A (CPA) with the expectation that these compounds exhibit improved inhibitory activities over 2-benzyl-3-mercaptopropanoic acid (BMPA), a potent CPA competitive inhibitor, possibly having additional interactions of their amino group with the carboxylate of Glu-270 of the enzyme upon binding to CPA. Contrary to the expectation, however, the CPA inhibitory potencies of these compounds were found to be much reduced compared with that of BMPA, suggesting that the amino group in the inhibitors rather exerts steric hindrance in binding of these inhibitors to CPA.

Yeast에 의한 휘발성 유기화합물 분해에 있어서의 기질상호관계 해석 (Substrate Interactions in the Biodegradation of Volatile Organic Compounds by a Yeast Strain)

  • 장현섭;정미영;신승규;송지현;황선진
    • 상하수도학회지
    • /
    • 제22권2호
    • /
    • pp.187-193
    • /
    • 2008
  • Biological removal capacities for volatile organic compounds (VOCs) were determined using a yeast strain, Candida tropicalis. In this study, VOCs including toluene, benzene, p-xylene, and styrene as single substrates or mixtures were tested in the batch culture of the yeast strain. In addition, a kinetic model was applied to evaluate substrate interactions between the VOCs. The yeast strain was able to biodegrade each VOC effectively as a growth substrate, implying it could applied to wide range of VOCs. When the yeast strain was subjected to VOCs in mixtures, the biodegradation rate of one substrate were either increased (stimulated) or decreased (inhibited) by the presence of the others. Both benzene and toluene were inhibited by the other VOCs, and substrate interaction parameters estimated in the model indicated that styrene was the strongest inhibitor for the benzene and toluene biodegradation. Meanwhile, the biodegradation of p-xylene and styrene was stimulated by the presence of either benzene or toluene. The biodegradation rate of p-xylene was significantly increased especially by the presence of toluene, and the styrene biodegradation was enhanced greatly by the benzene addition. The results of the substrate interaction by the yeast strain suggest that the biodegradation rates for the VOCs in mixtures should be carefully evaluated. Furthermore, the competitive inhibition coefficient could be applied as a useful index to determine the substrate interaction

플립러닝을 활용한 체육과 경쟁활동 교수학습 모형개발 (The Development of Teaching and Learning Model in Physical Education and Competitive Activities Using Flipped Learning)

  • 전기찬;이동엽
    • 문화기술의 융합
    • /
    • 제8권5호
    • /
    • pp.351-357
    • /
    • 2022
  • 본 연구는 체육과 경쟁활동 플립러닝 교수학습 모형을 개발하고 그 모형의 타당성을 확인하는 것을 목적으로 수행되었다. 우리는 본 연구의 목적 달성을 위한 연구 방법으로 모형 연구 방법을 활용하였는데, 먼저 모형 개발 연구를 통하여 체육과 경쟁활동 플립러닝 교수학습 모형을 개발하였고, 이어서 모형 타당화 연구를 통하여 모형의 타당화 작업을 수행하였다. 본 연구를 통하여 개발한 교수학습 모형을 바탕으로 학교 현장의 체육 수업에서 학생은 수동적인 학습자에서 능동적인 학습자로 변화할 수 있고, 모형 내에서 제시한 협력형 활동을 통하여 기존의 체육 수업과는 다른 학습자간의 상호작용을 바탕으로 수업 목표를 달성할 수 있을 것으로 기대된다.

미국 대학과 기업간 연계의 발전 과정 (Development of Interactions between Higher Education Institutions and Companies in the U.S.)

  • 김형주
    • 한국경제지리학회지
    • /
    • 제8권1호
    • /
    • pp.51-70
    • /
    • 2005
  • 지식이 경쟁력을 결정짓는 주요 원천으로 강조되고 있으며, 고등 교육을 필요로 하는 지식 인력에 대한 수요가 크게 늘어난 지식 기반 사회에서, 대학 교육과 경제 발전의 관계가 점차 강조되고 있다. 대학들은 최근 변화의 시대에 직면하여 교육 기능과 더불어 대학 연구의 상품화나 기업가 정신의 고양에 힘쓰고 있는 한편, 기업들은 빠르게 변화하고 점차 복잡해지는 기술 환경 속에서 외부와의 연계를 추구하고 있다. 이에 따라 대학들은 기업들의 혁신 과정에 공헌함으로써 국가와 지역 경제 발전에 이바지하고 있다. 본 연구는 발전된 대학 교육 시스템과 효율적으로 운영되는 대학과 기업간 연계를 보여주고 있는 미국의 사례를 역사적으로 고찰하여 우리나라의 대학과 기업간 연계에 대한 연구에 시사점을 제시하고자 한다. 이를 위해 미국 대학의 종류와 특성을 살피고, 대학과 기업간 연계의 발전 과정을 역사적으로 분석하며, 미국이 세계적인 경쟁 우위를 가지고 있는 정보 기술 분야를 사례로 산업의 특성과 대학과 기업간 연계의 발전 과정을 정리한다. 끝으로 복잡하고 다층적인 대학과 기업간 연계 관계의 주요 유형들을 정리하여 대학과 기업 연계에 대한 이후 연구에 개념적 틀을 제시한다.

  • PDF

Characterization of Ca2+-Dependent Protein-Protein Interactions within the Ca2+ Release Units of Cardiac Sarcoplasmic Reticulum

  • Rani, Shilpa;Park, Chang Sik;Sreenivasaiah, Pradeep Kumar;Kim, Do Han
    • Molecules and Cells
    • /
    • 제39권2호
    • /
    • pp.149-155
    • /
    • 2016
  • In the heart, excitation-contraction (E-C) coupling is mediated by $Ca^{2+}$ release from sarcoplasmic reticulum (SR) through the interactions of proteins forming the $Ca^{2+}$ release unit (CRU). Among them, calsequestrin (CSQ) and histidine-rich $Ca^{2+}$ binding protein (HRC) are known to bind the charged luminal region of triadin (TRN) and thus directly or indirectly regulate ryanodine receptor 2 (RyR2) activity. However, the mechanisms of CSQ and HRC mediated regulation of RyR2 activity through TRN have remained unclear. We first examined the minimal KEKE motif of TRN involved in the interactions with CSQ2, HRC and RyR2 using TRN deletion mutants and in vitro binding assays. The results showed that CSQ2, HRC and RyR2 share the same KEKE motif region on the distal part of TRN (aa 202-231). Second, in vitro binding assays were conducted to examine the $Ca^{2+}$ dependence of protein-protein interactions (PPI). The results showed that TRN-HRC interaction had a bell-shaped $Ca^{2+}$ dependence, which peaked at pCa4, whereas TRN-CSQ2 or TRN-RyR2 interaction did not show such $Ca^{2+}$ dependence pattern. Third, competitive binding was conducted to examine whether CSQ2, HRC, or RyR2 affects the TRN-HRC or TRN-CSQ2 binding at pCa4. Among them, only CSQ2 or RyR2 competitively inhibited TRN-HRC binding, suggesting that HRC can confer functional refractoriness to CRU, which could be beneficial for reloading of $Ca^{2+}$ into SR at intermediate $Ca^{2+}$ concentrations.

회계정보시스템 아웃소싱의 결정요인과 성공요인에 관한 실증연구 (An Empirical Study on the Determinant Factors and Success Factors of Accounting Information Systems Outsourcing)

  • 정준수;송신근;천면중
    • Asia pacific journal of information systems
    • /
    • 제11권1호
    • /
    • pp.91-115
    • /
    • 2001
  • Faced with tougher competition in global, organizations are pressured to improve organizational productivity, including information systems(IS) departments. Especially related to IS, trying to remain competitive and up-to-date in rapidly changing world is becoming a financial burden to many organizations. Through outsourcing, organizations can provide better services and acquire and maintain a competitive advantage. In recent years IS outsourcing related researches have appeared in trade and academic literature. However the research on accounting information systems(AIS) outsourcing is very little or limited. This study attempts to empirically test the relationship between determinant factors and the degree of accounting information systems outsourcing as well as the relationship between success factors and the interactions between the degree of accounting information systems outsourcing and outsourcing success. Based on the previous studies on IS outsourcing and its related theories, determinant factors(transaction characteristic, resource performance, and risk dependence) and success factors(monitor, participation, and vendor capability) were identified and their measures were developed. Empirical results demonstrate that the change in the degree of AIS outsourcing is determined by the specificity of accounting information asset, uncertainty, the effect of internal AIS, AIS cost-effectiveness, and cost increase risks, and that monitor and vendor capability are implementation factors determining the degree of outsourcing success.

  • PDF

토착 미생물을 이용한 MTBE와 BTEX의 혐기성 생분해 연구 (A Study on Anaerobic Biodegradation of MTBE and BTEX by Indigenous Microorganisms)

  • 정우진;장순웅
    • 한국지하수토양환경학회지:지하수토양환경
    • /
    • 제21권3호
    • /
    • pp.88-94
    • /
    • 2016
  • The simultaneous biodegradation between MTBE (Gasoline additives) and BTEX (Benzene, Toluene, Ethyl-benzene, o-Xylene, m-Xylene, p-Xylene) was achieved within a competitive inter-relationship, with not only electron accepters such as nitrate, sulfate, and iron(III) without oxygen, but also with electron donors such as MTBE and BTEX. Preexisting indigenous microorganisms from a domestic sample of gasoline contaminated soil was used for a lab-scale batch test. The result of the test showed that the biodegradation rate of MTBE decreased when there was co-existing MTBE and BTEX, compared to having just MTBE present. The growth of indigenous microorganisms was not affected in the case of the MTBE treatment, whereas the growth of the microorganisms was decreased in combined MTBE and BTEX sample. This may indicate that an inhibitor related to biodegradation when BTEX and MTBE are mixed will be found. This inhibitor may be found to retard the anaerobic conditions needed for efficient breakdown of these complex carbon chain molecules in-situ. Moreover, it is also possible that an unknown competitive reaction is being imposed on the interactions between MTBE and BTEX dependent on conditions, ratios of mixture, etc.

조직시민행동이 정보시스템 사용성과에 미치는 영향: 흡수능력의 매개역할을 중심으로

  • 길진호;곽기영
    • 한국경영정보학회:학술대회논문집
    • /
    • 한국경영정보학회 2008년도 춘계학술대회
    • /
    • pp.525-540
    • /
    • 2008
  • With the competitive pressure and the development of information and communication technology, many organizations have introduced various kinds of enterprise-wide systems like enterprise resource planning (ERP) systems as strategic tools for the purpose of improving organizational performance. Despite their promised strategic benefits, however, their implementation has suffered from a high failure rate and difficulty in realizing the anticipated benefits. Previous studies have indicated that one of the most critical failure reasons is the lack of knowledge sharing and utilization across organizations. As a consequence, many information systems (IS) researchers have paid attention to examining the effect of absorptive capacity closely associated with knowledge sharing and transferring on IS usage performance. ERP systems implementation involves changes not only in systems but also in processes and other social dimensions, which can be related to organizational citizenship behavior (OCB) requiring appropriate communications and interactions among organizational members. A lack of communications and interactions due to a lack of OCB might lead to weak absorptive capacity and thus negatively influence knowledge sharing across organizations, because OCB facilitates a successful collaboration among functional units and positively impacts individual's attitude toward radical organizational change. With this motivation, this study has two research objectives. First, it introduces and tests a theoretical model accounting for the relationships among performance of ERP system usage, absorptive capacity, and OCB. Second, it examines a mediating role of absorptive capacity between OCB and performance of EPR system usage. Theoretical and practical implications of the study ware discussed, along with its limitations.

  • PDF

Effects of Morphine and Panax ginseng on the Opioid Receptor-G protein Interactions

  • Kim, Young-Ran;Kim, Ae-young;Kim, Kyeong-Man
    • Biomolecules & Therapeutics
    • /
    • 제7권1호
    • /
    • pp.1-6
    • /
    • 1999
  • Effects of Panax ginseng on the morphine toxicity were studied in relation to its effects on the opioid receptor-G protein interactions. Morphine treatments (3 days) reduced the body weight increment rate and the weight of the thymus and spleen. These changes were usually recovered by the concomitant administration of ginseng total saponin (GTS) but occasionally further deteriorated. This discrepancy was studied in relation to the opioid receptor coupling to G protein, that is, the effects of morphine and GTS on the opioid receptors were studied using the antagonist-agonist competitive binding studies. When GTS recovered the morphine toxicity, morphine shifted the striatal $\delta$ receptors to slightly higher affinity state, and this was partly recovered by the GTS treatment. However, morphine did not have any effect on the affinity state of $\delta$ receptor from NG108-15 cells, suggesting that additional factors were needed for the modulation of the affinity states of $\delta$ receptor. Effects of morphine and GTS on $\mu$ receptor were complicate and variable, and we could not reach a clear conclusion. The morphine toxicity might accompany complicate biological involvements, and the modulation of the affinity states of the opioid receptors might explain a part of the effects of GTS on the morphine toxicity.

  • PDF

경영전략과 최고경영자 특성이 기업성과에 미치는 영향: 벤처기업을 중심으로 (Competitive strategies, CEO characteristics, and firm performance in venture businesses)

  • 박경미;황재원
    • 한국산학기술학회논문지
    • /
    • 제20권1호
    • /
    • pp.52-63
    • /
    • 2019
  • 전략분야의 연구들은 일정 수준 이상 성공한 대기업을 대상으로 실증분석을 실시함으로써 제대로 된 성과함의를 도출하지 못할 여지가 있다. 이러한 측면에서 미래 시점에 성공할 기업과 실패할 기업이 현재 시점에 혼재되어 있는 벤처기업을 대상으로 논의의 타당성을 검증함으로써 보다 변별력 있는 연구결과를 획득할 가능성은 높아질 수 있다. 본 연구는 경영전략과 최고경영자의 특성, 그리고 이들 간의 상호작용효과가 기업성과에 미치는 영향에 대한 가설을 제시하고, 387개 벤처기업으로부터 회수된 설문에 근거하여 실증분석을 실시함으로써 전략분야의 논의들이 어떤 타당성을 가지는지를 벤처기업을 대상으로 검증하고자 하였다. 분석결과에 따르면 경영전략 중에서는 기술혁신 차별화 전략이, 최고경영자의 특성 중에서는 혁신성과 장기지향성이 기업성과에 유의한 영향을 미치는 것으로 나타났다. 또한 경영전략과 최고경영자의 특성 간의 상호작용효과의 경우 원가우위 전략과 마케팅 차별화 전략은 위험감수성향, 혁신성, 장기지향성 모두에 대해 유의한 결합효과를 보여주었다. 반면에 기술혁신 차별화 전략은 최고경영자의 특성 중 어느 것과도 유의한 결합효과를 보여주지 않았다. 이를 통해 원가우위 전략과 마케팅 차별화 전략은 기업성과에 단독으로 영향을 미치지 않고 최고경영자의 특성과 결합될 때 영향을 미치는 반면. 기술혁신 차별화 전략은 기업성과에 단독으로 영향을 미치지만 최고경영자의 특성과는 결합효과가 존재하지 않는다는 결론에 도달하였다. 본 연구는 벤처기업의 성과제고를 위해서는 경영전략과 최고경영자의 특성 간에 적합성을 추구하는 것이 중요하다는 사실을 실증분석을 통해 확인했다는 점에서 의의를 가진다.