• Title, Summary, Keyword: Scanning electron microscopy

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Reconstruction of Neural Circuits Using Serial Block-Face Scanning Electron Microscopy

  • Kim, Gyu Hyun;Lee, Sang-Hoon;Lee, Kea Joo
    • Applied Microscopy
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    • v.46 no.2
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    • pp.100-104
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    • 2016
  • Electron microscopy is currently the only available technique with a spatial resolution sufficient to identify fine neuronal processes and synaptic structures in densely packed neuropil. For large-scale volume reconstruction of neuronal connectivity, serial block-face scanning electron microscopy allows us to acquire thousands of serial images in an automated fashion and reconstruct neural circuits faster by reducing the alignment task. Here we introduce the whole reconstruction procedure of synaptic network in the rat hippocampal CA1 area and discuss technical issues to be resolved for improving image quality and segmentation. Compared to the serial section transmission electron microscopy, serial block-face scanning electron microscopy produced much reliable three-dimensional data sets and accelerated reconstruction by reducing the need of alignment and distortion adjustment. This approach will generate invaluable information on organizational features of our connectomes as well as diverse neurological disorders caused by synaptic impairments.

The development of scanning electron microscopy (전자현미경 개발)

  • Oh H. J.;Chang D. Y.;Yang H. N.;Kim D. H.;Park M, J.;Shim C. H.;Kim C. S.
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • pp.15-18
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    • 2005
  • We have designed and fabricated a thermal scanning electron microscopy. It includes an electron source, two condenser lenses, one objective lens, a scanning coil and a stigmator coil for focusing in column and also have a secondary electron detector for constructing the image in chamber with a high vacuum condition and control part for operating the SEM. Especially, in order for us to find out the optical characteristics, our attention and studies have been concentrated on the effects of two condenser lenses and one objective lens for high resolution with SEM. Finally, we developed a high resolution thermal scanning electron microscopy.

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Precise Comparison of Two-dimensional Dopant Profiles Measured by Low-voltage Scanning Electron Microscopy and Electron Holography Techniques

  • Hyun, Moon-Seop;Yoo, Jung-Ho;Kwak, Noh-Yeal;Kim, Won;Rhee, Choong-Kyun;Yang, Jun-Mo
    • Applied Microscopy
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    • v.42 no.3
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    • pp.158-163
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    • 2012
  • Detailed comparison of low-voltage scanning electron microscopy and electron holography techniques for two-dimensional (2D) dopant profiling was carried out with using the same multilayered p-n junction specimen. The dopant profiles obtained from two methods are in good agreement with each other. It demonstrates that reliability of dopant profile measurement can be increased through precise comparison of 2D profiles obtained from various microscopic techniques.

Analysis of Ceramics Using Scanning Electron Microscopy (주사전자현미경을 활용한 세라믹의 분석)

  • Lee, Sujeong
    • Ceramist
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    • v.22 no.4
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    • pp.368-380
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    • 2019
  • A ceramic is used as a key material in various fields. Accordingly, the use of scanning electron microscopy is increased for the purpose of evaluating the reliability and defects of advanced ceramic materials. The scanning electron microscope is developed to overcome the limitations of optical microscopy and uses accelerated electrons for imaging. Various signals such as SE, BSE and characteristic X-rays provide useful information about the surface microstructure of specimens and, the content and distribution of chemical components. The development of electron guns, such as FEG, and the improved lens system combined with the advanced in-lens detectors and STEM-in-SEM system have expanded the applications of SEM. Automated SEM-EDS analysis also greatly increases the amount of data, enabling more statistically reliable results. In addition, X-ray CT, XRF, and WDS, which are installed in scanning electron microscope, have transformed SEM a more versatile analytical equipment. The performance and specifications of the scanning electron microscope to evaluate ceramics were reviewed and the selection criteria for SEM analysis were described.

Morphological Discretion of Basidiospores of the Puftball Mushroom Calostoma by Electron and Atomic Force Microscopy

  • Kim, Mi-Sun;Kim, Ki-Woo;Jung, Hack-Sung
    • Journal of Microbiology and Biotechnology
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    • v.17 no.10
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    • pp.1721-1726
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    • 2007
  • Comparative morphology among species of the genus Calostoma, including C. cinnabarina, C. ravenelii, and C. japonicum, was investigated by scanning electron microscopy and atomic force microscopy. Spore morphology of C. cinnabarina and C. ravenelii showed no dramatic differences by light microcopy and scanning electron microscopy. To differentiate these species, atomic force microscopy was employed. Quantitative analysis of the surface roughness of basidiospores revealed subtle differences in height fluctuation at the nanometer scale between the species of Calostoma. Basidiospores of C. cinnabarina had a relatively rougher surface than those of C. ravenelii at $2.0{\times}2.0\;{\mu}m^2$ scan areas.

Tissue Preparation with t-Butyl Alcohol Freeze-drying Method for Scanning Electron Microscopy: Application for Rat Liver (t-Butyl Alcohol 동결건조법을 이용한 흰쥐 간장의 주사전자현미경적 관찰)

  • Uhm, Chang-Sub;Park, Eun-Kyung;Park, Chang-Hyun
    • Applied Microscopy
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    • v.28 no.3
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    • pp.299-306
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    • 1998
  • T-butyl alcohol (TBA) freeze-drying method originally designed by Inoue and Osadake (1989) was adopted to dry specimens for scanning electron microscopy and the results were compared with those dried using critical point dryer (CPD). Small pieces $(1\times1\times3mm)$ of liver of Sprague-Dawley rats were cut and fixed in 2% glutaraldehyde in 0.1 M sodium cacodylate buffer after anesthesia, and processed for scanning electron microscopy by several modifications of TBA freeze-drying methods and by the standard preparation method using CPD. The bile canaliculi and sinusoidal endothelial surface were observed. Tissue dehydrated with TBA before TBA freeze-drying preserved the structures best comparable to those prepared with CPD. This result suggests that combination of dehydration with TBA and TBA freeze-drying is a superior method to the original TBA freeze-drying method dehydrated with ethanol.

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A Study on the Scanning Electron Microscopy of the Buffalo Mammary Gland

  • Dang, A.K.;Ludri, R.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.1
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    • pp.101-103
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    • 2001
  • Scanning Electron Microscopy of twelve lactating buffalo mammary gland was done. The lactating mammary gland showed alveolus, arrangement of blood vessels and myoepithelial cells on the alveolus, the formation of lobules and interlobular connective tissue. From the exposed alveolar lumen fat globule formation can be seen which is still attached to the alveolar surface by microvilli. This technique should further be extended to study the alveolar structure in detail during different stages of mammary gland development in buffaloes.

Realization for Each Element for capturing image in Scanning Electron Microscopy (주사 전자 현미경에서 영상 획득에 필요한 구성 요소 구현)

  • Lim, Sun-Jong;Lee, Chan-Hong
    • Journal of Korean Society of Laser Processing
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    • v.12 no.2
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    • pp.26-30
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    • 2009
  • Scanning Electron Microscopy (SEM) includes high voltage generator, electron gun, column, secondary electron detector, scan coil system and image grabber. Column includes electron lenses (condenser lens and objective lens). Condenser lens generates fringe field, makes focal length and control spot size. Focal length represents property of lens. Objective lens control focus. Most of the electrons emitted from the filament, are captured by the anode. The portion of the electron current that leaves the gun through the hole in the anode is called the beam current. Electron beam probe is called the focused beam on the specimen. Because of the lens and aperture, the probe current becomes smaller than the beam current. It generate various signals(backscattered electron, secondary electron) in an interaction with the specimen atoms. In this paper, we describe the result of research to develop the core elements for low-resolution SEM.

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Characteristics of Auditory Stereocilia in the Apical Turn of the Echolocating Bats by Scanning Electron Microscopy

  • Kim, Jinyong;Jung, Yongwook
    • Applied Microscopy
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    • v.44 no.1
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    • pp.8-14
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    • 2014
  • The auditory system of the Korean greater horseshoe bat (Rhinolophus ferrumequinum korai, RFK) is adapted to its own echolocation signal, which consist of constant frequency (CF) element and frequency modulated (FM) element. In contrast, the Japanese long-fingered bat (Miniopterus schreibersii fuliginosus, MSF) emits FM signals. In the present study, the characteristics of stereocilia in RFK (a CF/FM bat) and MSF (a FM bat) were studied in the apical turn of the cochlea where the lower frequencies are transduced. Stereocilia lengths and numbers were quantitatively measured in RFK by scanning electron microscopy and compared with those of MSF. Each inner hair cells (IHCs) of RFK possessed three rows of stereocilia, whereas MSF possessed five rows of stereocilia. Gradients in stereocilia lengths and numbers of stereocilia of the IHCs of RFK were found to be less pronounced and fewer, respectively, than those of MSF. Each outer hair cells (OHCs) possessed three rows of stereocilia in both species. OHCs stereocilia in RFK that distinguished it from MSF were a shorter length and a greater number of stereocilia. These features suggest that the apical cochleas of RFK are adapted for the processing of higher frequency echolocation calls rather than that of MSF.