• 제목/요약/키워드: Competitive interactions

검색결과 91건 처리시간 0.021초

약물과 생체고분자간의 상호작용(II) Difference Spectra에 의한 Cephalothin 및 Cefazoline과 Human Serum Albumin의 결합에 관한 연구 (Drug-Biomacromolecule Interactions (II) Binding of Cephalothin and Cefazoline to Human Serum Albumin Using Difference Spectrophotometry)

  • 김종국;양지선;안해영;김양배;유병설
    • 약학회지
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    • 제25권4호
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    • pp.161-165
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    • 1981
  • The binding of two cephalosporins, cephalothin and cefazoline to human serum albumin(HSA) was studied by difference spectrophotometry using a spectrophotometric probe, 2-(4'-hydroxybenzeneazo) benzoic acid. The probe is strong visible absorbing material which interacts with serum albumin to give characteristic spectrophotometric peaks and provides the basis for a convenient assay to measure free and bound amounts in the presence of serum albumin and competitive drugs. The results obtained showed that the probe and cephalosporin compete for the same binding site on human serum albumin; thus the probe can be used to gauge the displacement of cephalosporins from human serum albumin. The data were interpreted on the basis of theory of multiple equilibria. The number of binding sites of human serum albumin for 2-(4'-hydroxybenzeneazo) benzoic acid(HBAB), cephalothin and cefazoline appears to be 4. By using this technique the binding constants were found as follows: HSA-HBAB, $7.89{\times}10^{4}M^{-1}$; HSA-cephalothin, $1.09{\times}10^{3}M^{-1}$ ; HSA-cefazoline, $1.21{\times}10^{3}M^{-1}$.

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Study of the Adsorbent-Adsorbate Interactions from Cd(II) and Pb(II) Adsorption on Activated Carbon and Activated Carbon Fiber

  • Kim, Dae Ho;Kim, Doo Won;Kim, Bo-Hye;Yang, Kap Seung;Lim, Yong-Kyun;Park, Eun Nam
    • 대한화학회지
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    • 제57권1호
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    • pp.104-108
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    • 2013
  • The adsorption characteristics of Cd(II) and Pb(II) in aqueous solution using granular activated carbon (GAC), activated carbon fiber (ACF), modified ACF (NaACF), and a mixture of GAC and NaACF (GAC/NaACF) have been studied. The surface properties, such as morphology, surface functional groups, and composition of various adsorbents were determined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The specific surface area, total pore volume, and pore size distribution were investigated using nitrogen adsorption, Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) methods. In this study, NaACF showed a high adsorption capacity and rate for heavy metal ions due to the improvement of its ion-exchange capabilities by additional oxygen functional groups. Moreover, the GAC and NaACF mixture was used as an adsorbent to determine the adsorbent-adsorbate interaction in the presence of two competitive adsorbents.

2중 음이온 체계내에서 시슬 Bt토양의 흡착부위에 대한 황산이온의 경쟁 (Competition of Sulfate for Sorption Sites of Cecil Bt Soil in Binary Anion System)

  • 정덕영
    • 농업과학연구
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    • 제23권2호
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    • pp.250-260
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    • 1996
  • Observed results of the adsorption between two competing anions for the shared sorption sites represent that the adsorption phenomena may depends on the characteristics of anion and available sorption sites in a given conditions. In binary systems, adsorption of one species can significantly influence the fate of the other anion, resulting in control of the extent of solute-adsorbate distributions throughout soil profile. And the proton-donation mechanisms by organic anions having a carboxyl as a functional group can also influence the adsorption of inorganic anions onto the hydroxylated sites of Fe and Al oxides. However, study of competitive adsorption of specifically adsorbed anions illustrates some of difficulties which arise in interpretation of reactions at oxide/aqueous solution interfaces. At least two factors prevented a simple analysis of reactions. First, at any pH value the maximum amount of adsorbate taken up at the surface depends on the identity of the anion. Second, it was necessary to postulate the sorption sites where the anion can be adsorbed. Hence, anions having non-specific adsorption characteristics are less capable for sorption sites, compared to those of specific adsorption characteristics, even though competition complies both ordinary and electrostatic interactions for sorption sites. Therefore, competition among chemical species in soil matrix can be of major significance in determining the effective mobility of any reactive anions with sorption sites.

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대학병원 근무 간호사의 성격적 특성, 권한부여 및 고객지향성간의 관계분석 (An Analysis on the Relationship among Personality Traits, Empowerment and Customer Orientation of Nurses in a Teaching Hospital)

  • 윤경일
    • 한국병원경영학회지
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    • 제8권2호
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    • pp.5-23
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    • 2003
  • To survive in the competitive environment, hospitals pay more attention to patient satisfaction than ever before. Nurses are the employee that have frequent interactions with patients in a hospital, and therefore, the effective management of nursing staff is crucial to maintain high level of patient satisfaction. Searching for a way to an effective human resource management in nursing, this study attempted to investigate the pre-dispositional factors of customer orientation of registered nurses in a hospital. The customer orientation concept is originated from marketing literature and defined as the attitude of employee that focus on establishing a long term relationship rather than short term gains in dealing with customers. The study hypothesized that the personal trait of individual and the perceived level of empowerment affect the level of customer orientation of nurses. We tested the hypothesis 10 a teaching hospital. Three-hundred seventy two nurses were surveyed and 235 responses were collected. Out of the 235 responses, 24 responses were discarded due to the incomplete answers to the questionnaire and 211 responses were analyzed. The data were analyzed using factor analysis and multiple regression analysis. The results showed that the enjoyment dimension of customer orientation was affected by the agreeableness, consciousness, and openness of personal traits and the need dimension of customer orientation was affected by the agreeableness and level of empowerment. Based on the results the research and nursing resources management implications were discussed.

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연속적 시뮬레이션 모델을 이용한 대학정보화의 도입효과 분석 (Analysis of University Information System Based on the Continuous Simulation Model)

  • 박영홍;김경수
    • 한국산업정보학회논문지
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    • 제5권3호
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    • pp.10-17
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    • 2000
  • 오늘날의 대학사회는 정보통신분야의 비약적인 기술혁신으로 큰 변혁을 맞이하고 있다. 첨단의 정보통신시설과 국제적 감각을 갖춘 대학만이 총 공급이 총 수요를 초과하게 되는 미래의 대학 현실에서 생존할 수 있다는 전제 아래 경쟁 대학을 능가하는 생산성제고가 대학 최고의 경영목표가 되고 있다. 세계화, 국제화, 정보화 추세 속에서 사회의 학문적 욕구는 점점 다양해지고 세분화되면서 맞춤 교육과 미래사회가 필요로 하는 지적욕구의 충족을 요구하고 있다. 따라서 대학은 생존을 위한 전략으로 정보화 시스템을 도입하여 교육의 질적 향상을 도모하면서 최상의 교육을 통해 다양한 사회의 지적 욕구에 대응하고 있다. 본 연구는 연속적 시뮬레이션 모델을 이용하여 대학이 정보화를 추진하기 전, 그 효과를 사전에 측정. 평가함으로써 합리적으로 도입수준, 규모 및 내용 등을 결정할 수 있는 방법을 제시한다. 즉 시뮬레이션 모델을 통해 대학이 교육 및 행정의 정보화를 추진함에 있어 이에 수반되는 비용과 이로 인한 효과를 업무의 효율성 증가 및 경쟁력 제고 측면에서 분석하여 최적의 대학정보화의 도입수준을 결정하고 정보화에 대한 투자효율을 극대화시키기 위한 하나의 척도를 제공하게 된다.

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Antiferroelectric and antiferrodistortive phase transitions in Ruddlesden-Popper Pb2TiO4 from first-principles

  • Xu, Tao;Shimada, Takahiro;Wang, Jie;Kitamura, Takayuki
    • Coupled systems mechanics
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    • 제6권1호
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    • pp.29-40
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    • 2017
  • This work employed density functional theory to investigate the structural and ferroelectric properties of the Ruddlesden-Popper (RP) phase of lead titanate, $Pb_2TiO_4$, as well as its phase transitions with epitaxial strain. A wealth of novel structural instabilities, which are absent in the host $PbTiO_3$ material, were identified in the RP phase through phonon soft-mode analysis. Our calculations showed that the ground state of $Pb_2TiO_4$ is antiferroelectric, distinct from the dominant ferroelectric phase in the corresponding host material. In addition, applied epitaxial strain was found to play a key role in the interactions among the instabilities. The induction of a sequence of antiferroelectric and antiferrodistortive (AFD) phase transitions by epitaxial strain was demonstrated, in which the ferroic instability and AFD distortion were cooperative rather than competitive, as is the case in the host $PbTiO_3$. The RP phase in conjunction with strain engineering thus represents a new approach to creating ferroic orders and modifying the interplay among structural instabilities in the same constituent materials, enabling us to tailor the functionality of perovskite oxides for novel device applications.

Light Regulation of rbcL Transcript and Protein-binding Region on rbcL Promoter in Maize

  • Lee, Jae-Seon;Sim, Woong-Seop
    • Journal of Plant Biology
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    • 제39권4호
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    • pp.279-286
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    • 1996
  • To know the changes of rbcL mRNA level by illumination, Northern hybridization analysis was performed with maize (Zea mays L.cv. Golden X Bantam). The average level of rbcL. mRNA in the light-grown shoots was 3.1 times higher than that of the dark-grown shoots after 6 to 10 growth days. The maximum difference of rbcL mRNA level between the dark-grown and the light-grown shoots was 5.1 folds. These results indicate that accumulation of rbcL mRNAin maize shoots is induced by light. Since the transcriptional DNA binding proteins and their cognate promoter elements, we carried out gel-retardation assays to elucidate the specific binding proteins on the rbcL promoter. It was found that plastid proteins of light-grown shoots bound to the R2 DNA fragment (-33 to -229) and R3 DNA fragment (-230 to -418 from ATG) of the rbcL promoter. From the results of competitive binding assays and heat or protease treatments, it was demonstrated that the bindings were sequence-specific DNA-protein interactions. Therefore, it could be concluded that the rbcL promoter region has at least two specific recognition sites for plastid proteins.

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Biogenic Volatile Compounds for Plant Disease Diagnosis and Health Improvement

  • Sharifi, Rouhallah;Ryu, Choong-Min
    • The Plant Pathology Journal
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    • 제34권6호
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    • pp.459-469
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    • 2018
  • Plants and microorganisms (microbes) use information from chemicals such as volatile compounds to understand their environments. Proficiency in sensing and responding to these infochemicals increases an organism's ecological competence and ability to survive in competitive environments, particularly with regard to plant-pathogen interactions. Plants and microbes acquired the ability to sense and respond to biogenic volatiles during their evolutionary history. However, these signals can only be interpreted by humans through the use of state-of the-art technologies. Newly-developed tools allow microbe-induced plant volatiles to be detected in a rapid, precise, and non-invasive manner to diagnose plant diseases. Beside disease diagnosis, volatile compounds may also be valuable in improving crop productivity in sustainable agriculture. Bacterial volatile compounds (BVCs) have potential for use as a novel plant growth stimulant or as improver of fertilizer efficiency. BVCs can also elicit plant innate immunity against insect pests and microbial pathogens. Research is needed to expand our knowledge of BVCs and to produce BVC-based formulations that can be used practically in the field. Formulation possibilities include encapsulation and sol-gel matrices, which can be used in attract and kill formulations, chemigation, and seed priming. Exploitation of biogenic volatiles will facilitate the development of smart integrated plant management systems for disease control and productivity improvement.

LMX, 임파워먼트 그리고 혁신행동 간의 상황적 인과모형: 내국인과 외국인 근로자의 비교분석을 중심으로 (Situational Causal Model Between LMX, Empowerment and Innovation Behavior)

  • 유병남
    • 대한안전경영과학회지
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    • 제23권4호
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    • pp.121-133
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    • 2021
  • The composition of human resources in industrial sites is becoming global. In Korea, too, the proportion of foreign members in all industrial fields and production sites is increasing. This is the reason why an approach that reflects this reality is needed in the basic unit of competitive sources. Competitiveness starts with value creation, and this progresses through field innovation. Through empirical analysis of this study, it was analyzed that South Korea members showed active actions and attitudes in developing, promoting, and realizing ideas when they strongly recognized the real meaning of empowerment given by leaders. On the other hand, it was found that foreign members do not know the meaning of empowerment itself, so they are often unable to play an active role in the development, promotion, and realization of ideas. In fact, it was analyzed that foreign members generally did not experience positive interactions with LMX and were exposed to simple tasks and controls. In other words, they are being discriminated against in terms of communication problems, compensation system, and work environment. In particular, this phenomenon is exacerbated in the case of small and medium-sized enterprises (SMEs). Situational response to foreign workers through improvement of LMX and empowerment should be evaluated as a key management task in a situation where productivity improvement and job unit innovation are urgently needed.

EVALUATION OF COST-TIME RELATIONSHIPS FOR CONTRACTORS PARTICIPATING IN COST-PLUS-TIME BIDDING

  • Saeed Abdollahi Sean Pour;Hyung Seok David Jeong
    • 국제학술발표논문집
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    • The 5th International Conference on Construction Engineering and Project Management
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    • pp.479-487
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    • 2013
  • State Highway Agencies (SHAs) have started utilizing cost-plus-time bidding (A+B bidding) since Federal Highway Agency (FHWA) declared it operational on May 4, 1995. Although this technique has successfully accelerated many projects by incorporating construction time in the bidding competition, a framework to illustrate the interactions of incentive/disincentive (I/D) rates on the competitiveness of contractors participating in the bid competition is yet to be developed. In a previous research, authors indicated that for each bid competition there is an efficient cap for I/D rates which are dictated by the capabilities of contractors in project acceleration. However, the results of previous study were based on the assumption that there is a statistically significant relationship between cost and time. In this study, the entire cost-plus-time projects implemented by the Oklahoma Department of Transportation (ODOT) were investigated. Then the significance of relationship between cost and time were analyzed for each contractor utilizing Analysis of Variance (ANOVA) technique, and the price-time function of each contractor was determined by regression analysis. The results of the analysis indicate that there is a significant relationship between cost and time for the majority of contractors. However, a quadratic relationship is not always significant and for some contractors a linear price-time relationship is significant. The results of this project can be used not only by ODOT to optimize the incentive/disincentive rates but also by contractors to determine the most competitive strategies of other bid participants.

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