• 제목/요약/키워드: many-body interactions

검색결과 43건 처리시간 0.03초

Ab initio Calculations of Protonated Ethylenediamine-(water)3 Complex: Roles of Intramolecular Hydrogen Bonding and Hydrogen Bond Cooperativity

  • 부두완
    • Bulletin of the Korean Chemical Society
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    • 제22권7호
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    • pp.693-698
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    • 2001
  • Ab initio density functional calculations on the structural isomers, the hydration energies, and the hydrogen bond many-body interactions for gauche-, trans-protonated ethylenediamine-(water)3 complexes (g-enH+(H2O)3, t-enH+(H2O)3) have been performed. The structures and relative stabilities of three representative isomers (cyclic, tripod, open) between g-enH+(H2O)3 and t-enH+(H2O)3 are predicted to be quite different due to the strong interference between intramolecular hydrogen bonding and water hydrogen bond networks in g-enH+(H2O)3. Many-body analyses revealed that the combined repulsive relaxation energy and repulsive nonadditive interactions for the mono-cyclic tripod isomer, not the hydrogen bond cooperativity, are mainly responsible for the greater stability of the bi-cyclic isomer.

Fermi Velocity Renormalization in Graphene

  • Hwang, Choongyu;Siegel, David A.;Lanzara, Alessandra
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.163.1-163.1
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    • 2014
  • Electron-electron interactions bear important information on fundamental electronic properties such as electron effective mass, conductivity, and charge mobility. By using angle-resolved photoemission spectroscopy, here we address unusual electron self-energy in graphene induced by the electron-electron interactions, which are distinguished from those of an ordinary Fermi liquid. Our findings provide a new route for two-dimensional electron systems toward device applications.

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항우울제와 연관약물의 약물상호작용 (Antidepressants and Related Drug Interactions)

  • 이민수
    • 생물정신의학
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    • 제7권1호
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    • pp.21-33
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    • 2000
  • As the clinical practice of using more than one drug at a time increase, the clinician is faced with ever-increasing number of potential drug interactions. Although many interactions have little clinical significances, some may interfere with treatment or even be life-threatening. This review provides a better understanding of drug-drug interactions often encountered in pharmacotherapy of depression. Drug interactions can be grouped into two principal subdivisions : pharmacokinetic and pharmacodynamic. These subgroups serve to focus attention on possible sites of interaction as a drug moves from the site of administration and absorption to its site of action. Pharmacokinetic processes are those that include transport to and from the receptor site and consist of absorption, distribution on body tissue, plasma protein binding, metabolism, and excretion. Pharmacodynamic interactions occur at biologically active sites. In this review, emphasis is placed on antidepressant medications, how they are metabolized by the P450 system, and how they alter the metabolism of other drugs. When prescribing antidepressant medications, the clinician must consider the drug-drug interactions that are potentially problematic.

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내외과계 환자의 정신과 약물치료에서 약물-약물 상호작용 - 고려대학교 부속병원의 자문조정의 경험을 통하여 - (Drug-drug Interactions between Psychotropic Agents and Other Drugs in Physically Ill Patients - Experience of Consultation-liason in Korea University Hospital -)

  • 이민수;이헌정
    • 생물정신의학
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    • 제6권1호
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    • pp.49-66
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    • 1999
  • Polypharmacotherapy, both psychotropic and nonpsychotropic, is widespread in various situations including psychiatric hospitals and general hospitals. As the clinical practice of using more than one drug at a time increase, the clinician is faced with ever-increasing number of potential drug interactions. Although many interactions have little clinical significances, some may interfere with treatment or even be life-threatening. The objective of this review is evaluation for drug-drug interactions often encountered in psychiatric consultation. Drug interactions can be grouped into two principal subdivisions : pharmacokinetic and pharmacodynamic. These subgroups serve to focus attention on possible sites of interaction as a drug moves from the site of administration and absorption to its site of action. Pharmacokinetic processes are those that include transport to and from the receptor site and consist of absorption, distribution on body tissue, plasma protein binding, metabolism, and excretion. Pharmacodynamic interactions occur at biologically active sites. In psychiatric consultation, these two subdivisions of drug interactions between psychotropic drugs and other drugs are likely to happen. We gathered informations of the drugs used in physically ill patients who are consulted to psychiatric department in Korea University Hospital. And we reviewed the related literatures about the drug-drug interactions between psychotropic drugs and other drugs.

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감성공간디자인의 실증적 연구-II (An Empirical Study on Emotional Space Design-II)

  • 오영근
    • 한국실내디자인학회논문집
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    • 제21권1호
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    • pp.103-110
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    • 2012
  • With a theoretical focus on the emotional experiences created via the interface, and the relationship between human beings and space, this study aims to corroborate and clarify the formation and verification of emotional interactions between human beings and space using body movements. It follows the method of Coining "Movement Phrases" through the analysis of body movements in the experimental space, thereby developing them into a complete scenario to produce the story of emotional expression. This study has hereby generated the following outcomes: First, the "pocket-type" exhibition displays a higher frequency of body movements than the "general" exhibition. It has close connections with emotional vocabularies: "Curious," "interesting," "warm," and "fun." The "general" exhibition records a relatively high frequency of emotional vocabularies like "natural," "efficient," and "free." Second, it is possible to analyze the story of space using a scenario, just like drama, based upon attributes and serial relationships. The "exposition" section reveals a high degree of "curiosity" and a large number of body movements, while the "development" section indicates high degree of "surprise" plus slight body movements. The "transition" sections manifest high "interest" and many body movements, and the "climax" section shows a high frequency of "surprise" and many changes in body movements. The "conclusion" section finally invokes images together with body movements.

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Car-Parrinello Molecular Dynamics Study for the Isotope Effect on OH Vibration in Ice Ih

  • Yoon, Yeohoon
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.553-557
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    • 2013
  • The stretching vibration of OH of ice Ih is studied by Car-Parrinello molecular dynamics in regarding the effect of mixed H/D contamination while the vibrational spectrum is considered by velocity-velocity autocorrelations of the sampled ensemble. When hydrogen atoms are immersed randomly into the deuterated ice, a typical vibrational frequency of OH stretching mode is observed to be similar to that from the pure $H_2O$ ice. When focusing on the correlation of isolated neighboring OH stretching, a narrower and blue shifted peak is observed at the high frequency range as a result of the screening from the complex many body correlations by $D_2O$ environment. It is also specifically related to the symmetric intermolecular correlations between neighboring OH stretching modes. More enhanced high frequency range can be explained by the expansion of such two body correlations to collective many body correlations among all possible OH stretching modes. This contribution becomes important when it involves in chemical interactions via excitation of such vibrational states.

Network Graph Analysis of Gene-Gene Interactions in Genome-Wide Association Study Data

  • Lee, Sungyoung;Kwon, Min-Seok;Park, Taesung
    • Genomics & Informatics
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    • 제10권4호
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    • pp.256-262
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    • 2012
  • Most common complex traits, such as obesity, hypertension, diabetes, and cancers, are known to be associated with multiple genes, environmental factors, and their epistasis. Recently, the development of advanced genotyping technologies has allowed us to perform genome-wide association studies (GWASs). For detecting the effects of multiple genes on complex traits, many approaches have been proposed for GWASs. Multifactor dimensionality reduction (MDR) is one of the powerful and efficient methods for detecting high-order gene-gene ($G{\times}G$) interactions. However, the biological interpretation of $G{\times}G$ interactions identified by MDR analysis is not easy. In order to aid the interpretation of MDR results, we propose a network graph analysis to elucidate the meaning of identified $G{\times}G$ interactions. The proposed network graph analysis consists of three steps. The first step is for performing $G{\times}G$ interaction analysis using MDR analysis. The second step is to draw the network graph using the MDR result. The third step is to provide biological evidence of the identified $G{\times}G$ interaction using external biological databases. The proposed method was applied to Korean Association Resource (KARE) data, containing 8838 individuals with 327,632 single-nucleotide polymorphisms, in order to perform $G{\times}G$ interaction analysis of body mass index (BMI). Our network graph analysis successfully showed that many identified $G{\times}G$ interactions have known biological evidence related to BMI. We expect that our network graph analysis will be helpful to interpret the biological meaning of $G{\times}G$ interactions.

USING AN ABSTRACTION OF AMINO ACID TYPES TO IMPROVE THE QUALITY OF STATISTICAL POTENTIALS FOR PROTEIN STRUCTURE PREDICTION

  • Lee, Jin-Woo
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제15권3호
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    • pp.191-199
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    • 2011
  • In this paper, we adopt a position specific scoring matrix as an abstraction of amino acid type to derive two new statistical potentials for protein structure prediction, and investigated its effect on the quality of the potentials compared to that derived using residue specific amino acid identity. For stringent test of the potential quality, we carried out folding simulations of 91 residue A chain of protein 2gpi, and found unexpectedly that the abstract amino acid type improved the quality of the one-body type statistical potential, but not for the two-body type statistical potential which describes long range interactions. This observation could be effectively used when one develops more accurate potentials for structure prediction, which are usually involved in merging various one-body and many-body potentials.

약물 정보 문서 임베딩을 이용한 딥러닝 기반 약물 간 상호작용 예측 (Prediction of Drug-Drug Interaction Based on Deep Learning Using Drug Information Document Embedding)

  • 정선우;유선용
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2022년도 춘계학술대회
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    • pp.276-278
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    • 2022
  • 모든 약물은 신체 내에서 특정한 작용을 하며, 많은 경우 합병증 또는 기존 약물치료 중 새롭게 발생하는 증상에 의해 약물이 혼용되는 경우가 발생한다. 이런 경우 신체 내에서 예상치 못한 상호작용이 발생할 수 있다. 따라서 약물 간 상호작용을 예측하는 것은 안전한 약물 사용을 위해 매우 중요한 과제이다. 본 연구에서는 다중 약물 사용 시 발생 가능한 약물 간 상호작용 예측을 위해 약물 정보 문서를 이용해 학습시키는 딥러닝 기반의 예측 모델을 제안한다. 약물 정보 문서는 DrugBank 데이터를 이용해 약물의 작용 기전, 독성, 표적 등 여러 속성을 결합해 생성되었으며, 두 약물 문서가 한 쌍으로 묶여 딥러닝 기반 예측 모델에 입력으로 사용되고 해당 모델은 두 약물 간 상호작용을 출력한다. 해당 연구는 임베딩 방법이나 데이터 전처리 방법 등 다양한 조건의 변화에 따른 실험 결과의 차이를 분석하여 차후 새로운 약물쌍 간 상호작용을 예측하는 데에 활용이 가능하다.

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마네킨 설계 파라메타 분석연구 (Development of Methods of Constructing Family of Manikin)

  • 김진호;황민철
    • 대한산업공학회지
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    • 제22권4호
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    • pp.663-675
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    • 1996
  • Equipment designer should consider how many people and what range of percentiles will be used as design criteria. The usual practice is to select some large range of the accommodation, such as 5th-95th percentiles. There is difficulty in defining 95% accommodation of population in complex design problems which involve several body dimensions. This paper develops the methods of constructing family of manikins which are validated for population accommodation. They are analyzed by the interactions or relationships between body dimensions. Proposed manikin family represents multivariate body dimensions. Moreover, nine manikin families are determined for representative Korean of 30-50 aged by proposed manikin family. Their 2-D CAD modelings are developed for bio-mechanical and ergonomic applications.

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