Yasunori Nawa

Shizuoka University, Sizuoka, Shizuoka, Japan

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Publications (4)10.07 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: We developed a high-resolution fluorescence microscope in which fluorescent materials are directly excited using a focused electron beam. Electron beam excitation enables detailed observations on the nanometer scale. Real-time live-cell observation is also possible using a thin film to separate the environment under study from the vacuum region required for electron beam propagation. In this study, we demonstrated observation of cellular components by autofluorescence excited with a focused electron beam and performed dynamic observations of intracellular granules. Since autofluorescence is associated with endogenous substances in cells, this microscope can also be used to investigate the intrinsic properties of organelles.
    Biomedical Optics Express 02/2014; 5(2):378-86. · 3.18 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Multi-color, high spatial resolution imaging of fluorescent nanodiamonds (FNDs) in living HeLa cells has been performed with a direct electron-beam excitation-assisted fluorescence (D-EXA) microscope. In this technique, fluorescent materials are directly excited with a focused electron beam and the resulting cathodoluminescence (CL) is detected with nanoscale resolution. Green- and red-light-emitting FNDs were employed for two-color imaging, which were observed simultaneously in the cells with high spatial resolution. This technique could be applied generally for multi-color immunostaining to reveal various cell functions.
    ChemPhysChem 01/2014; · 3.35 Impact Factor
  • W. Inami, Y. Nawa, Y. Kawata
    [show abstract] [hide abstract]
    ABSTRACT: We present superresolving optical imaging system and demonstrate the observation of biological specimens without any stained process. The electron-beam excited assisted (EXA) optical microscope has a few tens nanometer spatial resolution laterally and is possible to observe dynamic behaviors of specimens in various surroundings such as air or liquids. In the EXA-microscope, a nano-light source in a few nanometers size is excited by focused electron beam in an emission layer. An electron beam can be focused to a spot size as small as 1 nanometer in diameter. The EXA-microscope enables to observe optical constants such as absorption, refractive index, polarization properties, and its dynamic behaviors in nanometer scale. We also have developed a direct electron-beam excitation assisted optical microscope with a resolution of a few tens of nanometers and it can be applied for observation of dynamic movements of nanoparticles in liquid. In the microscope, fluorescent materials are directly excited with a focused electron beam. In this paper we present the evaluation result of resolution and observation results of living HeLa cells with high resolution. We have successfully observed fine structures of the cells without any stain process. This is first demonstration of observation of intercellular granules in HeLa cells.
    QiR (Quality in Research), 2013 International Conference on; 01/2013
  • [show abstract] [hide abstract]
    ABSTRACT: We propose a direct electron-beam excitation assisted optical microscope with a resolution of a few tens of nanometers and it can be applied for observation of dynamic movements of nanoparticles in liquid. The technique is also useful for live cell imaging under physiological conditions as well as observation of colloidal solution, microcrystal growth in solutions, etc. In the microscope, fluorescent materials are directly excited with a focused electron beam. The direct excitation with an electron beam yields high spatial resolution since the electron beam can be focused to a few tens of nanometers in the specimens. In order to demonstrate the potential of our proposed microscope, we observed the movements of fluorescent nanoparticles, which can be used for labelling specimens, in a water-based solution. We also demonstrated an observation result of living CHO cells.
    Optics Express 02/2012; 20(5):5629-35. · 3.55 Impact Factor

Publication Stats

7 Citations
106 Views
10.07 Total Impact Points

Institutions

  • 2012–2014
    • Shizuoka University
      • Graduate School of Science and Technology
      Sizuoka, Shizuoka, Japan