• Title/Summary/Keyword: molecular distribution

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Molecular Structural Properties of Legume Starches (두류 전분의 분자구조적 특성)

  • Kweon, Mee-Ra;Ahn, Seung-Yo
    • Korean Journal of Food Science and Technology
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    • v.25 no.3
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    • pp.264-269
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    • 1993
  • Molecular structural properties of legume starches were investigated. In intrinsic viscosity and degree of Polymerization of amylose and amylopectins, cow pea and mung bean were high, but kidney bean was low. Low molecular weight fractions for kidney bean starch were much eluted by gel chromatography. In the elution profiles of their amylose by Sepharose 2B-CL, molecular weight of kidney bean amylose was smaller than that of other amylose Molecular weights of cow pea and mung bean amyloses were large, but that of kidney bean amylose was small and red bean amylose was medium. The elution profiles by Sephadex G-50 after debranching amylopectins with pullulanase showed similar patterns.

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Molecular Modeling of Enantio-discrimination of α-Methoxy-α-trifluoromethylphenylacetic Acid (MTPA) by Cyclomaltoheptaose (β-Cyclodextrin) and 6-Amino-6-deoxy-cyclomaltoheptaose

  • Jung, Eun-Kyoung;Jeong, Karp-Joo;Lee, Sang-San;Kim, Jee-In;Jung, Seun-Ho
    • Bulletin of the Korean Chemical Society
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    • v.24 no.11
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    • pp.1627-1631
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    • 2003
  • Molecular modeling was performed to comprehend the chiral recognition of ${\alpha}$-methoxy-${\alpha}$-trifluoromethylphenylacetic acid (MTPA) enantiomers by cyclomaltoheptaose (${\beta}$-cyclodextrin,${\beta}$-CD) and 6-amino-6-deoxy-cyclomaltoheptaose (am-${\beta}$-CD). Monte Carlo (MC) docking coupled to constant temperature molecular dynamics (MD) simulations was applied to the investigation for the ${\alpha}$-methoxy-${\alpha}$-trifluoromethylphenylacetic acid complexation with two different CDs in terms of the relative distribution of the interaction energies. The calculated results are finely correlated with the experimental observations in chiral recognition thermodynamics. Am-${\beta}$-CD as a host showed the superior enantio-discrimination ability to the native ${\beta}$-CD where the amino group of am-${\beta}$-CD was critically involved in enhancing the ability of chiral discrimination via the Coulombic interaction with MTPA.

Synthesis and characterization of Star Shape Polycaprolactone containing 4-Arm Polycaprolactone Core (4개의 폴리카프로락톤 가지 코어를 가지는 스타형 폴리카프로락톤의 합성 및 분석)

  • An, Sung-Guk;Cho, Chang-Gi
    • Proceedings of the Korean Fiber Society Conference
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    • 2002.04a
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    • pp.199-202
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    • 2002
  • The synthesis of materials with controlled composition and architectures continues to be a focus of considerable current research. Dendritic multiarm polymers such as dendrimer, hyperbranched polymer, and star polymers are three dimensional macromolecules, in which a large number of linear arms of similar molecular weight and narrow molecular weight distribution emanate from a central core. (omitted)

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Preliminary Molecular Dynamics Simulations of the OSS2 Model for the Solvated Proton in Water

  • Lee, Song Hui
    • Bulletin of the Korean Chemical Society
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    • v.22 no.8
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    • pp.847-849
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    • 2001
  • The OSS2(Ojame-Shavitt-Singer 2)[L. Ojame et al., J. Chem. Phys. 109, 5547 (1998)] model as a dissociable water model is examined in order to study the dynamics of H+ in water. MD simulations for 216 water system, 215 water + H+ ion system, and 215 water + OH- ion system using the OSS2 model at 298.15 K with the use of Ewald summation are carried out. The calculated O-H radial distribution functions for these systems are essentially the same and are in very good agreement with that obtained by Ojame.

Leucine Zipper as a Fine Tuner for the DNA Binding; Revisited with Molecular Dynamics Simulation of the Fos-Jun bZIP Complex

  • 최용훈;양철학;김현원;정선호
    • Bulletin of the Korean Chemical Society
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    • v.20 no.11
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    • pp.1319-1322
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    • 1999
  • Leucine zipper dynamically tunes the degree of bifurcation of the DNA binding segments in the basic region of the Fos-Jun bZIP complex. Molecular dynamics simulation indicated that site-specific mutagenesis of conserved leucine residues inside the leucine zipper domain caused the change of dynamic behavior of the basic region, and efficient DNA binding occurs only within a certain range of distance between the two DNA binding segments in the basic region. Distribution of α-helices in the hinge region is also suggested to influence the bifurcation of the DNA binding segments.

On-Line Determination of dn/dc for Size Exclusion Chromatography Coupled with a Light Scattering Detector

  • 이희정;장태현
    • Bulletin of the Korean Chemical Society
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    • v.16 no.7
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    • pp.640-643
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    • 1995
  • The internal standard method, which is widely used in chromatographic techniques, is applied to the size exclusion chromatography for the on-line determination of dn/dc value of the sample. This method is found to provide the dn/dc value with suitable accuracy in determining the absolute molecular weight and the molecular weight distribution of the polymers when a light scattering detector is used.

Kinetic Energy Release in the Fragmentation of tert-Butylbenzene Molecular Ions. A Mass-analyzed Ion Kinetic Energy Spectrometric (MIKES) Study

  • Choe, Joong-Chul;Kim, Byung-Joo;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
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    • v.10 no.2
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    • pp.167-171
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    • 1989
  • Kinetic energy release in the fragmentation of tert-butylbenzene molecular ion was investigated using mass-analyzed ion kinetic energy spectrometry. Method to estimate kinetic energy release distribution (KERD) from experimental peak shape has been explained. Experimental KERD was in good agreement with the calculated result using phase space theory. Effect of dynamical constraint was found to be important.

Distribution of Pathogenic Genes and Molecular Typing of Yersinia pseudotuberculosis isolated from Spring Water in Seoul

  • Kim, Mi-Sun;Shim, Mi-Ja
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.161.2-161.2
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    • 2003
  • In order to investigate the pathogenic genes and genetic relationships of Y. pseudotuberculosis, we isolated 9 strains of Y. pseudotuberculosis from about 380 spring water sites in Seoul and carried out antibiotic susceptibility test, biological test and molecular typing. All isolated strains were distributed throughout the northeast area in Seoul (Mt. Bookhan, Mt. Soorak, Mt. Boolam and etc...).Antibiotic susceptibility test revealed that all the strains were susceptible to chloramphenicol, gentamicin, neomycin and amoxicillin/clavulanic acid, but were resistant to novobiocin and vancomycin. (omitted)

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