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https://www.readbyqxmd.com/read/28633459/electron-microscopy-of-voids-in-si-formed-by-permeable-pulse-laser-irradiation
#1
Hiroyuki Iwata, Daisuke Kawaguchi, Hiroyasu Saka
Voids formed in Si by permeable laser irradiation were investigated by comprehensive electron microscopy. Two types of voids were identified: Type (1): This type was formed mostly closer to the entrance surface of a laser, and a considerable volume of a non-diamond Si (DS) phase was formed in the surrounding matrix. Type (2): This type was formed at the focus of an incident laser, and none of dislocations, cracks and non-DS phase was observed in the surrounding matrix. Type (1) voids are considered to be formed to accommodate volume change resulting from transformation from DS to the non-DS...
June 17, 2017: Microscopy
https://www.readbyqxmd.com/read/28637263/nearly-nondiffracting-electron-lattice-beams-generated-by-polygonal-slits
#2
Hiroki Nambu, Yuuki Noguchi, Koh Saitoh, Masaya Uchida
A method for generating electron lattice beams carrying vortices using nanofabricated polygonal slits in a transmission electron microscope is proposed. Experimental and simulation study of the intensity of the beams verified their Bessel beam-like nearly nondiffracting behavior. Phase analysis using a diffractive imaging method found arrays of quantized vortices, forming an electron beam lattice with cylindrical intensity distribution in the propagation direction. Such vortex lattice beams may be used in a variety of applications including nanofabrication, particle manipulation or a new electron imaging method...
June 15, 2017: Microscopy
https://www.readbyqxmd.com/read/28582514/conformation-and-dynamics-of-single-polymer-chain-studied-by-optical-microscopy-techniques-beyond-the-diffraction-limit
#3
Hiroyuki Aoki
The origin of the unique properties of a polymer material is the large entropic term of a single molecule, which has a chain-like structure with a large molecular weight. From the viewpoint of understanding the fundamental polymer physics, conformation of the single polymer chain is one of the most important matters; however, it has been difficult to examine the behavior of a single chain because of the limitation of conventional experimental methods. Recent developments in optical microscopy allow the fluorescence imaging beyond the diffraction limit of light, and the author's group showed that the conformation and the dynamics of a single polymer chain can be examined by the high-resolution fluorescence imaging...
June 5, 2017: Microscopy
https://www.readbyqxmd.com/read/28541401/three-dimensional-structural-labeling-microscopy-of-cilia-and-flagella
#4
Toshiyuki Oda
Locating a molecule within a cell using protein-tagging and immunofluorescence is a fundamental technique in cell biology, whereas in three-dimensional electron microscopy, locating a subunit within a macromolecular complex remains challenging. Recently, we developed a new structural labeling method for cryo-electron tomography by taking advantage of the biotin-streptavidin system, and have intensively used this method to locate a number of proteins and protein domains in cilia and flagella. In this review, we summarize our findings on the three-dimensional architecture of the axoneme, especially the importance of coiled-coil proteins...
May 25, 2017: Microscopy
https://www.readbyqxmd.com/read/28575515/microscopy-in-this-issue
#5
(no author information available yet)
No abstract text is available yet for this article.
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28430991/development-toward-high-resolution-x-ray-phase-imaging
#6
Atsushi Momose
Since the 1990s, the use of X-ray phase contrast has been extensively studied for imaging weakly absorbing objects consisting of low-Z elements such as biological soft tissues and polymers. The development of X-ray microscopy was also progressing during this time, although absorption contrast was only available. It was straightforward and important to develop phase-contrast X-ray microscopy. One characteristic in the development is that quantitative phase measurement is possible through the acquisition of phase-contrast images under a specific procedure, thanks to digital X-ray image detectors...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28339813/microstructural-observation-of-fuel-cell-catalyst-inks-by-cryo-sem-and-cryo-tem
#7
Junichi Shimanuki, Shinichi Takahashi, Hajime Tohma, Atsushi Ohma, Ayumi Ishihara, Yoshiko Ito, Yuri Nishino, Atsuo Miyazawa
In order to improve the electricity generation performance of fuel cell electric vehicles, it is necessary to optimize the microstructure of the catalyst layer of a polymer electrolyte fuel cell. The catalyst layer is formed by a wet coating process using catalyst inks. Therefore, it is very important to observe the microstructure of the catalyst ink. In this study, the morphology of carbon-supported platinum (Pt/C) particles in catalyst inks with a different solvent composition was investigated by cryogenic scanning electron microscopy (cryo-SEM)...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28339777/support-system-for-fine-focusing-and-astigmatism-correction-using-an-auditory-signal-in-scanning-electron-microscopy
#8
Eisaku Oho, Kazuhiko Suzuki, Sadao Yamazaki
The current study describes a new support system for fine focusing and near-perfect astigmatism correction for scanning electron microscopy (SEM). The signal-to-noise ratio of a series of SEM images obtained from fast scan rates (TV scan) was adopted as a new metric for evaluating focus. Measured signal-to-noise ratio values were converted to an acoustic signal (sound wave frequency) using digital image processing techniques, enabling the SEM user to evaluate image focus using the auditory modality. Accurate focusing and correcting astigmatism in general-purpose SEM is traditionally time-consuming and difficult...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28339765/stem-moir%C3%A3-analysis-for-2d-strain-measurements
#9
Akimitsu Ishizuka, Martin Hytch, Kazuo Ishizuka
A moiré pattern is created in a scanning transmission electron microscope (STEM) when the scan step is close to a crystalline periodicity. Usually, fringes are visible in only one direction, corresponding to a single set of lattice planes, but fringes can be formed in two directions or more. Using an accurate independent calibration, the strains in silicon devices have been determined from the spacing and orientation of one-directional STEM moiré fringes. In this report, we first discuss the origin of the STEM moiré, and then we show how an accurate calibration of the scan step can be obtained from the STEM moiré pattern itself, providing that we know initially only an approximate scan step and the planar spacing...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28339760/ultrastructural-immunohistochemical-study-of-l-type-amino-acid-transporter-1-4f2-heavy-chain-in-tumor-microvasculatures-of-n-butyl-n-4-hydroxybutyl-nitrosamine-bbn-induced-rat-bladder-carcinoma
#10
Eisuke Kume, Tomoko Mutou, Norio Kansaku, Hitoyuki Takahashi, Michael F Wempe, Masahiro Ikegami, Yoshikatsu Kanai, Hitoshi Endou, Shin Wakui
Angiogenesis is essential for tumor growth, and an enhanced vasculature supplying nutrients and oxygen might reflect malignant potential. L-type amino acid transporter 1 (LAT1/4F2hc) comprises a major nutrient transport system responsible for the Na+-independent transport of large neutral amino acids. Seventy five to seventy eight percent N-butyl-N-(4-hydroxybutyl) nitrosamine-induced rat bladder carcinoma cells showed high LAT1/4F2hc expression. While the intracarcinoma microvasculatures of fenestrated endothelial cells highly expressing LAT1/4F2hc might progressively transport essential amino acids from the microvasculatures to the extracellular matrix, non-fenestrated endothelial cells and pericytes did not...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28339656/development-of-a-real-time-wave-field-reconstruction-tem-system-i-incorporation-of-an-auto-focus-tracking-system
#11
Takahiro Tamura, Yoshihide Kimura, Yoshizo Takai
We have developed a real-time wave field reconstruction transmission electron microscope system that enables auto focus tracking at a video rate. In the developed system, a high-speed image calculation technique using a graphical processing unit was incorporated along with two techniques facilitating high-speed focus control using high-voltage modulation and weighted image integration using exposure time control. By utilizing these techniques, the sample drift induced in the Z-axis direction can be measured and automatically corrected for every 1/30 of a second...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28339650/convenient-method-for-better-preservation-of-fine-structures-of-cultured-macrophages-and-engulfed-yeast-cells-by-freeze-substitution-fixation
#12
Masashi Yamaguchi, Azusa Takahashi-Nakaguchi, Yuko Aida, Michiyo Sato-Okamoto, Hiroji Chibana
Rapid freeze-freeze substitution after glutaraldehyde fixation (CF-FS method) obtained the natural and fine structures of macrophages and engulfed yeast cells. Culturing macrophages on single hole molybdenum grids placed in culture dishes made possible the rapid freezing of cells by the 'open sandwich method'. This method may be convenient when rapid-freezing cannot be performed immediately, or when a rapid-freezing device is not available in the lab.
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28339639/comparative-structural-study-of-the-zona-radiata-of-the-eggs-of-three-gobiobotia-cyprinidae-teleostei-endemic-korean-freshwaters
#13
Woong Sun Choi, Jae Goo Kim, Jong Young Park
The genus Gobiobotia in Korea has only three species and all are endemic benthic freshwater fishes. Their oocytes were observed by light microscopy, scanning electron microscopy and transmission electron microscopy to investigate the characteristics of the zona radiata (ZR), a non-cellular envelope, which surrounds the egg. Various developmental cells appeared during the spawning season. During the yolk vesicles stage, which yolk vesicles are spherically developed in periphery of the cytoplasm and gradually increase in its number and size, the ZR becomes visible between its follicular layer and ooplasm...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28339603/optimization-of-stem-imaging-conditions-for-cryo-tomography
#14
Kazuhiro Aoyama, Kotaro Nagano, Kaoru Mitsuoka
For three-dimensional analysis of cryo-specimens using tomography at low and medium magnifications, the use of STEM images has some important advantages over TEM. A clear understanding of the electron dose in STEM is essential for optimized cryo-microscopy so a dose estimation technique for STEM imaging has been developed. The STEM convergence angle was shown to have a large impact on the image quality, in particular on the signal-to-noise ratio in the acquired images. Importantly, there is a clear trade-off between good STEM spatial resolution in the images with a large convergence angle and the signal-to-noise ratio, which is improved by reducing the convergence angle as much as possible...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28100660/secondary-electron-effect-on-electron-beam-induced-charging-of-sio2-particle-analyzed-by-electron-holography
#15
Hiroaki Suzuki, Zentaro Akase, Kodai Niitsu, Toshiaki Tanigaki, Daisuke Shindo
Charging of a SiO2 particle induced by electron illumination was investigated by changing the illuminated area of the particle and its support film through control of the position of the mask plate inserted in a transmission electron microscope illumination system. The electric fields around the charged SiO2 particle were analyzed using electron holography. The amount of charge was evaluated quantitatively by comparing the reconstructed phase images with the simulated phase images. When the support film was not covered against the incident electron beam, secondary electrons emitted from the conductive support film were attracted to the charged particle, resulting in particle discharge...
June 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28531263/in-vivo-dynamics-of-the-cortical-actin-network-revealed-by-fast-scanning-atomic-force-microscopy
#16
Yanshu Zhang, Aiko Yoshida, Nobuaki Sakai, Yoshitsugu Uekusa, Masahiro Kumeta, Shige H Yoshimura
Together with lamellipodia and stress fibers, a dynamic network of actin filaments in the cell cortex plays a major role in the maintenance of cell morphology and motility. In contrast to lamellipodia, which have been well studied in various motile cells, the dynamics of actin filaments in the cell cortex have not yet been clarified due to a lack of proper imaging techniques. Here, we utilized high-speed atomic force microscopy for live-cell imaging and analyzed cortical actin dynamics in living cells. We successfully measured the polymerization rate and the frequency of filament synthesis in living COS-7 cells, and examined the associated effects of various inhibitors and actin-binding proteins...
May 20, 2017: Microscopy
https://www.readbyqxmd.com/read/28453814/graphene-specimen-support-technique-for-low-voltage-stem-imaging
#17
Masao Yamashita, Matthew Ryan Leyden, Hidehito Adaniya, Martin Philip Cheung, Teruhisa Hirai, Yabing Qi, Tsumoru Shintake
The scanning transmission electron microscopy (STEM) mode of today's field emission scanning electron microscopes enables sub-nanometer resolution imaging. Graphene is a single-atom thick, electrically conductive material, making it an excellent specimen support for the low voltage STEM imaging of nanometer-sized objects such as viruses. Here we present low voltage STEM images of bacteriophage T4 recorded on highly cleaned graphene films. The results show that ultrathin graphene support films markedly improve image signal at low accelerating voltages...
April 27, 2017: Microscopy
https://www.readbyqxmd.com/read/28431172/quantitative-analysis-of-li-distributions-in-battery-material-li1-xfepo4-using-fe-m2-3-edge-and-valence-electron-energy-loss-spectra
#18
Shunsuke Kobayashi, Craig A J Fisher, Akihide Kuwabara, Yoshio Ukyo, Yuichi Ikuhara
The spatial distribution of Li ions in a lithium iron phosphate (Li1-xFePO4) single crystal after chemical delithiation is quantitatively investigated using Fe M2,3-edge and valence electron energy loss (EEL) spectroscopy techniques. Li contents between those of end-member compositions LiFePO4 and FePO4 are found to correspond to reproducible changes in Fe M2,3-edge and valence EEL spectra across an interface between LiFePO4 and FePO4 regions. Quantitative analysis of these changes is used to estimate the local valence states of Fe ions, from which the Li concentration in the intermediate phase can be deduced...
April 18, 2017: Microscopy
https://www.readbyqxmd.com/read/28423411/a-convenient-technique-for-live-cell-observation-on-the-surface-of-polytetrafluoroethylene-with-a-phase-contrast-microscope
#19
Naoto Inukai, Kazuaki Tanaka, Tatsuya Takizawa
Phase-contrast microscopy is a convenient technique for live-cell observation on the surface of materials with high optical transmittance. Here, we demonstrate a novel technique to observe living cells on the surface of materials with low optical transmittance, such as polytetrafluoroethylene (PTFE), which are widely used in biomaterials for blood-contacting devices. The surface of a cover glass was coated with a thin PTFE layer with sufficient transmittance, thereby enabling the observation of living cells on the PTFE surface with a phase-contrast microscope...
April 1, 2017: Microscopy
https://www.readbyqxmd.com/read/28423410/analysis-of-dislocation-configurations-in-a-0-0-1-fcc-single-crystal-by-electron-channeling-contrast-imaging-in-the-sem
#20
Ivan Gutierrez-Urrutia
We have investigated the dislocation configurations in a [0 0 1] single crystal of a face-centered alloy (316L stainless steel) by the electron channeling contrast imaging (ECCI) technique in the scanning electron microscope under controlled diffraction conditions. Specific dislocations such as piled-up dislocations and Lomer-Cottrell dislocations were characterized by the analysis of dislocation contrast and dislocation line trace analysis. The ECCI technique also allows the sound estimation of the local resolved stress acting on gliding dislocations by the analysis of the radius of curvature following a transmission electron microscopy-based geometrical approach...
April 1, 2017: Microscopy
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