KENBIKYO
Online ISSN : 2434-2386
Print ISSN : 1349-0958
Volume 46 , Issue 3
Showing 1-12 articles out of 12 articles from the selected issue
Feature Articles: New Trends and Prospects in High Voltage Electron Microscopy
  • Nobuo Tanaka
    2011 Volume 46 Issue 3 Pages 150-
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS
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  • Seiichi Watanabe, Shigeo Yatsu, Kenji Ohkubo
    2011 Volume 46 Issue 3 Pages 151-155
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    We report here the formation process of laser-induced nanostructures by means of the in-situ study using a laser-equipped high-voltage electron microscope (Laser-HVEM), which has been developed at HVEM lab., Hokkaido University. A nanosecond pulse Nd:YAG laser (Inlite II-20, Continuum) was mounted to a HVEM (H-1300, Hitachi, accelerating voltage: 1300 kV, point-to-point resolution: 0.204 nm) above the specimen position so that the lineally polarized laser beam can pass through a quartz window and irradiated the TEM specimen at an angle of 60º, which corresponds to a 30º (s-polarized) off-beam light incidence condition. We report in this article some our recent results on in situ experiments using the Laser-HVEM.

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  • Nobuo Tanaka, Jiro Usukura, Michiko Kusunoki, Yahachi Saito, Katuhiro ...
    2011 Volume 46 Issue 3 Pages 156-159
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    Recently, the environmental transmission electron microscopy (ETEM) is highlighted as well as ultra-high resolution transmission electron microscopy with spherical aberration correction. Various kinds of in-situ observations of specimens changed by physical, electrical and mechanical modulations are carried out in the ETEM. In 2010 Nagoya University installed the world-first environmental high-voltage electron microscope, where observations under gas-injection up to 10,000Pa (≅1/10 atmosphere), light and mechanical modulations and three-dimensional tomography are performed for thicker specimens. In this article, the background of development and the preliminary data by using the instrument are reported.

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  • Hidehiro Yasuda
    2011 Volume 46 Issue 3 Pages 160-164
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    The 3MV ultra-high voltage electron microscope in Osaka University has advantages in researches utilizing both wave and particle motion of electrons. In this review, several examples of the researches based on the high transparency, in situ observation and electron radiation effects are listed, and the meaning of non-equilibrium materials science by a combination of radiation effects and in situ observation is shown. As one of recent researches, electron-irradiation-induced non-equilibrium phase transitions in Pd nanoparticles are introduced. When point defects are introduced and frozen by electron irradiation in Pd nanoparticles kept at low temperature, Pd nanoparticles with the fcc structure change from the random crystalline structure to the hcp structure with increasing of the atomic mean square displacements by formation of stacking faults and accumulated lattice strain. Additionally, the importance of researches on the dynamic non-equilibrium materials science using 3MV ultra-high voltage electron microscope is suggested as the future respect.

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  • Kazuhiro Yasuda, Kazufumi Yasunaga, Kenichi Shiiyama, Syo Matsumura
    2011 Volume 46 Issue 3 Pages 165-169
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    Oxides with fluorite structure are known as radiation tolerant ceramics, and have potential applications to advanced fuels of light water reactors, and to inert matrix for the burning and transmutation of minor actinoids and long-lived fission products. This paper reports the nucleation-and-growth of dislocation loops in fluorite structure oxides, such as ceria and yittria stabilized cubic zirconia, formed under electron irradiation. Transmission electron microscopy analysis has shown that the nature of dislocation loops strongly depends on electron energy: dislocation loops formed by energetic electrons less than around 1.3 MeV was found to be faulted dislocation loops consist of oxygen ions lying on {111} planes, and they have revealed anomalous growth process and multiplied dislocations when their size reached at a critical size. On the other hand, perfect dislocation loops on {110} planes were formed at higher electron energies where elastic displacements were induced on both cation and anion sublattice. A role of the selective displacement damage in oxygen sublattice was discussed based on the analysis on TEM images and results obtained by molecular dynamic simulations.

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  • Kazuyoshi Murata, Ryuichi Shigemoto
    2011 Volume 46 Issue 3 Pages 170-174
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    The electron microscopy in biological materials mainly requests three conditions of 1) electron transparency in thick sample, 2) high resolving power, and 3) low damage to the specimen. Almost of these conditions are achieved by high-voltage electron microscope. In this article, we describe the specifications required in the electron microscopes in biological materials. Image examples obtained with q high voltage electron microscope are also introduced. Finally, based on recent technological innovation in electron microscopy, we survey a future direction of the high voltage electron microscope in biology.

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Reviews
  • Nobuo Tanaka
    2011 Volume 46 Issue 3 Pages 175-180
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    Since the latter part of 1990, aberration correction technology, particularly of spherical aberration correction, has been developed. Its installation first started on TEM and next on STEM, which realized the point-to-point resolution of electron microscopes less than 0.1 nm. Recently, chromatic aberration correction instruments are also developed in Germany and Japan. The next targets of electron microscopy are the point-to-point resolution less than 0.04 nm (=40 pm) and three-dimensional observation at atomic dimension. The present paper reviews the history and present status of aberration corrected electron microscopy in order to see the future prospects.

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  • Naoki Kashihara, Atsunori Kuwabara, Hajime Nagasu, Shinya Kobayashi, Y ...
    2011 Volume 46 Issue 3 Pages 181-187
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    Albuminuria is strongly associated with cardiovascular disease. Individuals with albuminuria are more likely to die of CVD than to develop kidney failure. High blood pressure, poor glycemic control, obesity, metabolic syndrome, dyslipidemia, smoking and older age are the risk factors for susceptibility to and initiation of CKD. Glomerular hypertension and endothelial dysfunction are regarded as the common mechanisms underlying in the development of CKD. We have developed the novel techniques which enable us to visualize nitric oxide (NO) and reactive oxygen species (ROS) simultaneously in the tissue. Moreover, we have successfully innovated two-photon laser-microscopy to visualize microcirculation in the kidney in the living animals. These techniques are applicable to explore pathophysiology of many diseases.

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Lectures
  • Hirokazu Sasaki, Takeharu Kato, Takeyoshi Matsuda, Tsukasa Hirayama
    2011 Volume 46 Issue 3 Pages 188-194
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    The focused ion beam (FIB) technique has been indispensable for transmission electron microscopy (TEM) in the preparation of materials such as semiconductors, ceramics and metals, since it allows us to cut out specific parts from a bulk sample. However, it is well known that the high-voltage Ga ion beam damages the surface layers of TEM specimen. To avoid these problems, we have developed a FIB-Ar ion-milling technique to remove the FIB-damaged layers. In this paper, we applied this technique to the TEM specimen preparation for high-resolution transmission electron microscopy and electron holography.

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  • Shunichi Morikawa, Toshiyuki Watanabe, Taichi Ezaki
    2011 Volume 46 Issue 3 Pages 195-200
    Published: September 30, 2011
    Released: December 24, 2019
    JOURNALS FREE ACCESS

    Plasma leakage, caused by the hyper-permeability of blood vessel wall, is significant in the context of angiogenesis such as in regenerating tissues or tumors. We have developed a simple method to visualize blood vessels under a confocal laser scanning microscope by intravenous injection of fluorescent-conjugated tomato lectin that binds to glycocalyx of endothelia. Applying this method to the microcirculatory beds which contain hyper-permeable blood vessels, plasma leakage can be clearly visualized as well as the actual three-dimensional structure of the blood vessel networks, since lectin leaks out from the vessel wall together with plasma elements. Furthermore, by using “IMARIS”, a software program linked with Carl Zeiss confocal microscopes, fine three-dimensional images can be reconstructed from the confocal data, in which the volume of leaked lectin within a fixed area can be easily quantified. In this paper, we describe the practical procedure for the observation and quantification of plasma leakage in microcirculatory beds along with a concrete example of wound-healing animal model.

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