• Title/Summary/Keyword: Molecular data

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An Easy-to-Use Three-Dimensional Molecular Visualization and Analysis Program: POSMOL

  • Lee, Sang-Joo;Chung, Hae-Yong;Kim, Kwang S.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.7
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    • pp.1061-1064
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    • 2004
  • Molecular visualization software has the common objective of manipulation and interpretation of data from numerical simulations. They visualize many complicated molecular structures with personal computer and workstation, to help analyze a large quantity of data produced by various computational methods. However, users are often discouraged from using these tools for visualization and analysis due to the difficult and complicated user interface. In this regard, we have developed an easy-to-use three-dimensional molecular visualization and analysis program named POSMOL. This has been developed on the Microsoft Windows platform for the easy and convenient user environment, as a compact program which reads outputs from various computational chemistry software without editing or changing data. The program animates vibration modes which are needed for locating minima and transition states in computational chemistry, draws two and three dimensional (2D and 3D) views of molecular orbitals (including their atomic orbital components and these partial sums) together with molecular systems, measures various geometrical parameters, and edits molecules and molecular structures.

What Determines Star Formation Rates?

  • Evans, Neal
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.29.4-29.4
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    • 2016
  • The relations between star formation and properties of molecular clouds are studied based on a sample of star forming regions in the Galactic Plane. Sources were selected by having radio recombination lines to provide identification of associated molecular clouds and dense clumps. Radio continuum and mid-infrared emission were used to determine star formation rates, while 13CO and submillimeter dust continuum emission were used to obtain masses of molecular and dense gas, respectively. We test whether total molecular gas or dense gas provides the best predictor of star formation rate. We also test two specific theoretical models, one relying on the molecular mass divided by the free-fall time, the other using the free-fall time divided by the crossing time. Neither is supported by the data. The data are also compared to those from nearby star forming regions and extragalactic data. The star formation "efficiency," defined as star formation rate divided by mass, spreads over a large range when the mass refers to molecular gas; the standard deviation of the log of the efficiency decreases by a factor of three when the mass of relatively dense molecular gas is used rather than the mass of all the molecular gas.

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Complete Assignments of the 1H and 13C NMR Data of Flavone Derivatives

  • Moon, Byoung-Ho;Lee, Young-Shim;Shin, Choon-Shik;Lim, Yoong-Ho
    • Bulletin of the Korean Chemical Society
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    • v.26 no.4
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    • pp.603-608
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    • 2005
  • The $^1H\;and\;^{13}C$ chemical shifts of flavone and its five derivatives were determined completely using the basic 1D and 2D NMR experiments and molecular modeling. Of the six compounds used for our experiments, the NMR data of three compounds were published previously, but we found that the data of two compounds included wrong assignments. Therefore, we report the corrected data and the complete assignments of NMR data of the other three compounds.

Identification of three independent fern gametophytes and Hymenophyllum wrightii f. serratum from Korea based on molecular data

  • LEE, Chang Shook;LEE, Kanghyup;HWANG, Youngsim
    • Korean Journal of Plant Taxonomy
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    • v.50 no.4
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    • pp.403-412
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    • 2020
  • Colonies of three independent gametophytes (one that is filamentous and two that are ribbon-like) without sporophytes occur in Gyeonggi-do, Gangwon-do, Gyeongsang-do, and Jeju-do, Korea. They have a moss-like appearance at first sight, with tiny plantlets and gemmae, and grow in cool, shaded, relatively deep dint places of large rocks, such as the small caves in high mountains, close to valleys. The gametophytes were identified based on morphological and molecular data by chloroplast DNA (cpDNA) sequence data (rbcL, rps4 gene and rps4-trnS intergenic spacer). Here, rbcL, rps4 gene and rps4-trnS intergenic spacer data of one independent gametophyte distributed in Korea have the same morphology, DNA sequence and monophyletic group as Crepidomanes intricatum from the eastern United States. They also share the same cpDNA data with Crepidomanes schmidtianum recently reported from Korea. The other independent gametophyte should be Hymenophyllum wrightii based on cpDNA data. The last one was presumed to be Pleurosoriopsis makinoi based on molecular data. The taxonomic status was confirmed to be the forma of Hymenophyllum wrightii through a revision of Hymenophyllum wrightii f. serratum based on molecular data.

MOLECULAR GAS PROPERTIES UNDER ICM PRESSURE IN THE CLUSTER ENVIRONMENT

  • LEE, BUMHYUN;CHUNG, AEREE
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.491-494
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    • 2015
  • We present 12CO (2-1) data for four spiral galaxies (NGC 4330, NGC 4402, NGC 4522, NGC 4569) in the Virgo cluster that are undergoing different ram pressure stages. The goal is to probe the detailed molecular gas properties under strong intra-cluster medium (ICM) pressure using high-resolution millimeter data taken with the Submillimeter Array (SMA). Combining this with Institut de RadioAstronomie $Millim{\acute{e}}trique$ (IRAM) data, we also study spatially resolved temperature and density distributions of the molecular gas. Comparing with multi-wavelength data (optical, $H\small{I}$, UV, $H{\alpha}$), we discuss how molecular gas properties and star formation activity change when a galaxy experiences $H\small{I}$ stripping. This study suggests that ICM pressure can modify the physical and chemical properties of the molecular gas significantly even if stripping does not take place. We discuss how this affects the star formation rate and galaxy evolution in the cluster environment.

Deep-Learning-Based Molecular Imaging Biomarkers: Toward Data-Driven Theranostics

  • Choi, Hongyoon
    • Progress in Medical Physics
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    • v.30 no.2
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    • pp.39-48
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    • 2019
  • Deep learning has been applied to various medical data. In particular, current deep learning models exhibit remarkable performance at specific tasks, sometimes offering higher accuracy than that of experts for discriminating specific diseases from medical images. The current status of deep learning applications to molecular imaging can be divided into a few subtypes in terms of their purposes: differential diagnostic classification, enhancement of image acquisition, and image-based quantification. As functional and pathophysiologic information is key to molecular imaging, this review will emphasize the need for accurate biomarker acquisition by deep learning in molecular imaging. Furthermore, this review addresses practical issues that include clinical validation, data distribution, labeling issues, and harmonization to achieve clinically feasible deep learning models. Eventually, deep learning will enhance the role of theranostics, which aims at precision targeting of pathophysiology by maximizing molecular imaging functional information.

Taxonomic Position and Affinities of Isopyrum mandshuricum within Korean Isopyroideae (Ranunculaceae) Based on Molecular Data

  • Lee, Nam-Sook;Yeau, Sung-Hee;Kim, Ji-Hyun;Kim, Min-Ju
    • Animal cells and systems
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    • v.3 no.2
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    • pp.133-141
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    • 1999
  • To examine the taxonomic position and affinities of Isopyrum mandshuricum (Ranunculaceae) and related taxa, genetic analysis were carried out on the basis of isozyme patterns and ITS sequences. Molecular data, both isozyme patterns and ITS sequences suggest that I. mandshuricum is closely related to Enemion raddeanum than to Semiaquilegia adoxoides. The estimation of genetic identities by isozyme analysis reveals that I. manshuricum is genetically distant from E. raddeanum. The phylogenetic tree based on molecular data is rather congruent with the phenogram based on quantitative morphological characteristics, but not consistent with one based on qualitative morphological characteristics. Incongruencies between molecular and qualitative morphological data provide clues to re-evaluate several morphological features.

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Utility of Structural Information to Predict Drug Clearance from in Vitro Data

  • Lee, So-Young;Kim, Dong-Sup
    • Interdisciplinary Bio Central
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    • v.2 no.2
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    • pp.3.1-3.4
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    • 2010
  • In the present research, we assessed the utility of the structural information of drugs for predicting human in vivo intrinsic clearance from in vitro intrinsic clearance data obtained by human hepatic microsome experiment. To compare with the observed intrinsic clearance, human intrinsic clearance values for 51 drugs were estimated by the classical methods using in vivo-in vitro scale-up and by the new methods using the in vitro experimental data and selected molecular descriptors of drugs by the forward selection technique together. The results showed that taking consideration of molecular descriptors into prediction from in vitro experimental data could improve the prediction accuracy. The in vitro experiment is very useful when the data can estimate in vivo data accurately since it can reduce the cost of drug development. Improvement of prediction accuracy in the present approach can enhance the utility of in vitro data.

Informatics for protein identification by tandem mass spectrometry; Focused on two most-widely applied algorithms, Mascot and SEQUEST

  • Sohn, Chang-Ho;Jung, Jin-Woo;Kang, Gum-Yong;Kim, Kwang-Pyo
    • Bioinformatics and Biosystems
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    • v.1 no.2
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    • pp.89-94
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    • 2006
  • Mass spectrometry (MS) is widely applied for high throughput proteomics analysis. When large-scale proteome analysis experiments are performed, it generates massive amount of data. To search these proteomics data against protein databases, fully automated database search algorithms, such as Mascot and SEQUEST are routinely employed. At present, it is critical to reduce false positives and false negatives during such analysis. In this review we have focused on aspects of automated protein identification using tandem mass spectrometry (MS/MS) spectra and validation of the protein identifications of two most common automated protein identification algorithms Mascot and SEQUEST.

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Molecular Dynamics Simulation of First-Order Phase Transition (일차 상변화 과정의 분자 동력학적 모사)

  • Lee, Jae-Yeon;Yoon, Woong-Sup
    • 한국연소학회:학술대회논문집
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    • 2004.11a
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    • pp.161-166
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    • 2004
  • A study of argon droplet vaporization is conducted using molecular dynamics. Instead of using traditional method such as the Navier-Stokes equation. Molecular dynamics uses Lagrangian frame to describe molecular behavior in a system and uses only momentum and position data of all molecules in the system. So every property is not a hypothetical input but a statistical result calculated from the momentum and position data. This work performed a simulation of the first-order stability for phase transition of a three dementional submicron argon droplet within quiescent environment. Lennard-Jones 12-6 potential function is used as a intermolecular potential function. The molecular configuration is examined while an initially non-sperical droplet is changed into the spherical shape and droplet evaporates or condensates.

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