• Title/Summary/Keyword: Molecular approach

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A New Approach of Multi-Scale Simulation for Investigating Nano-Scale Material Deformation Behavior (나노스케일 재료 변형 거동을 위한 새로운 멀티스케일 접근법)

  • Park, Junyoung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.8 no.1
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    • pp.43-47
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    • 2009
  • Recently, an approach for nano-scale material deformation has been developed that couples the atomistic and continuum approaches using Finite Element Method (FEM) and Molecular Dynamics (MD). However, this approach still has problems to connect two approaches because of the difference of basic assumptions, continuum and atomistic modeling. To solve this problem, an alternative way is developed that connects the QuasiMolecular Dynamics (QMD) and molecular dynamics. In this paper, we suggest the way to make and validate the MD-QMD coupled model.

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Mechanical properties and deformation behavior of carbon nanotubes calculated by a molecular mechanics approach

  • Eberhardt, Oliver;Wallmersperger, Thomas
    • Smart Structures and Systems
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    • v.13 no.4
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    • pp.685-709
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    • 2014
  • Carbon nanotubes are due to their outstanding mechanical properties destined for a wide range of possible applications. Since the knowledge of the material behavior is vital regarding the possible applications, experimental and theoretical studies have been conducted to investigate the properties of this promising material. The aim of the present research is the calculation of mechanical properties and of the mechanical behavior of single wall carbon nanotubes (SWCNTs). The numerical simulation was performed on basis of a molecular mechanics approach. Within this approach two different issues were taken into account: (i) the nanotube geometry and (ii) the modeling of the covalent bond. The nanotube geometry is captured by two different approaches, the roll-up and the exact polyhedral model. The covalent bond is modeled by a structural molecular mechanics approach according to Li and Chou. After a short introduction in the applied modeling techniques, the results for the Young's modulus for several SWCNTs are presented and are discussed extensively. The obtained numerical results are compared to results available in literature and show an excellent agreement. Furthermore, deviations in the geometry stemming from the different models are given and the resulting differences in the numerical findings are shown. Within the investigation of the deformation mechanisms occurring in SWCNTs, the basic contributions of each individual covalent bond are considered. The presented results of this decomposition provide a deeper understanding of the governing deformation mechanisms in SWCNTs.

EMPAS: Electron Microscopy Screening for Endogenous Protein Architectures

  • Kim, Gijeong;Jang, Seongmin;Lee, Eunhye;Song, Ji-Joon
    • Molecules and Cells
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    • v.43 no.9
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    • pp.804-812
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    • 2020
  • In cells, proteins form macromolecular complexes to execute their own unique roles in biological processes. Conventional structural biology methods adopt a bottom-up approach starting from defined sets of proteins to investigate the structures and interactions of protein complexes. However, this approach does not reflect the diverse and complex landscape of endogenous molecular architectures. Here, we introduce a top-down approach called Electron Microscopy screening for endogenous Protein ArchitectureS (EMPAS) to investigate the diverse and complex landscape of endogenous macromolecular architectures in an unbiased manner. By applying EMPAS, we discovered a spiral architecture and identified it as AdhE. Furthermore, we performed screening to examine endogenous molecular architectures of human embryonic stem cells (hESCs), mouse brains, cyanobacteria and plant leaves, revealing their diverse repertoires of molecular architectures. This study suggests that EMPAS may serve as a tool to investigate the molecular architectures of endogenous macromolecular proteins.

Cyanobacterial Taxonomy: Current Problems and Prospects for the Integration of Traditional and Molecular Approaches

  • Komarek, Jiri
    • ALGAE
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    • v.21 no.4
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    • pp.349-375
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    • 2006
  • The application of modern ecological, ultrastructural and molecular methods, aided by the cultivation of numerous cyanobacterial morphotypes, has substantially changed our knowledge of these organisms. It has led to major advances in cyanobacterial taxonomy and criteria for their phylogenetic classification. Molecular data provide basic criteria for cyanobacterial taxonomy; however, a correct phylogenetic system cannot be constructed without combining genetic data with knowledge from the previous 150 years research of cyanobacterial diversity. Thus, studies of morphological variation in nature, and modern morphological, ultrastructural, ecophysiological and biochemical characters need to be combined in a “polyphasic” approach. Taxonomic concepts for generic and infrageneric ranks are re-evaluated in light of combined phenotypic and molecular criteria. Despite their usefulness in experimental studies, the limitations of using strains from culture collections for systematic and nomenclatural purposes is highlighted. The need for a continual revision of strain identification and proper nomenclatural practice associated with either the bacteriological or botanical codes is emphasized. Recent advances in taxonomy are highlighted in the context of prospects for understanding cyanobacterial diversity from natural habitats, and the evolutionary and adaptational processes that cyanobacteria undergo.

Insights into structural vaccinology harnessed for universal coronavirus vaccine development

  • Chin Peng Lim;Chiuan Herng Leow;Hui Ting Lim;Boon Hui Kok;Candy Chuah;Jonas Ivan Nobre Oliveira;Malcolm Jones;Chiuan Yee Leow
    • Clinical and Experimental Vaccine Research
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    • v.13 no.3
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    • pp.202-217
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    • 2024
  • Structural vaccinology is pivotal in expediting vaccine design through high-throughput screening of immunogenic antigens. Leveraging the structural and functional characteristics of antigens and immune cell receptors, this approach employs protein structural comparison to identify conserved patterns in key pathogenic components. Molecular modeling techniques, including homology modeling and molecular docking, analyze specific three-dimensional (3D) structures and protein interactions and offer valuable insights into the 3D interactions and binding affinity between vaccine candidates and target proteins. In this review, we delve into the utilization of various immunoinformatics and molecular modeling tools to streamline the development of broad-protective vaccines against coronavirus disease 2019 variants. Structural vaccinology significantly enhances our understanding of molecular interactions between hosts and pathogens. By accelerating the pace of developing effective and targeted vaccines, particularly against the rapidly mutating severe acute respiratory syndrome coronavirus 2 and other prevalent infectious diseases, this approach stands at the forefront of advancing immunization strategies. The combination of computational techniques and structural insights not only facilitates the identification of potential vaccine candidates but also contributes to the rational design of vaccines, fostering a more efficient and targeted approach to combatting infectious diseases.

A New Approach for Multi-Scale for Material Deformation (재료변형의 멀티스케일 해석에 관한 새로운 접근법)

  • Park J.;Kim Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.05a
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    • pp.62-65
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    • 2004
  • Recently, an approach for nanoscale deformation has been developed that couples the atomistic and continuum approaches using Finite Element Method (FEM) and Molecular Dynamics (MD). However, this approach still has problems to connect two approaches because of the difference of basic assumptions, continuum and atomistic. To solve this problem, an alternative way is developed that connects the quasimolecular dynamics (QMD) and molecular dynamics (MD). In this paper, we suggest the way to make and validate the MD-QMD coupled model.

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