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Journal of Electron Microscopy

Marie Kopecká, Soichi Yoshida, Masashi Yamaguchi
The unique long-neck yeast Fellomyces fuzhouensis has F-actin cables and cortical patches. Here, we describe a new F-actin structure present in fungi, a perinuclear F-actin collar ring around the cell nucleus. This F-actin structure can be visualized by fluorescent microscopic imaging of rhodamine-phalloidin-stained F-actin in cells treated with the mitotic drug isopropyl N-(3-chlorophenyl) carbamate or the microtubule inhibitor thiabendazol or when cells were grown in cut dried radish medium or yeast extract pepton dextrose (YEPD) medium...
August 2012: Journal of Electron Microscopy
Masao Inoue, Satoshi Suzuki, Zentaro Akase, Daisuke Shindo
Simulations were carried out for the orbit of electron-induced secondary electrons around a charged microfibril of a sciatic nerve tissue. In order to set the parameters for the simulation, the shape of the microfibril was determined from a transmission electron microscopy image, while the electric potential on the surface of the charged microfibril was evaluated from a reconstructed phase image obtained with electron holography. On the other hand, the passing point and the angle of secondary electrons at the microfibril surface were determined from a reconstructed amplitude image...
August 2012: Journal of Electron Microscopy
Yeong-Gi So, Koji Kimoto
We have investigated the effects of a small misalignment of the crystallographic orientation with respect to an incident probe (i.e. crystal tilt) on annular dark-field (ADF) imaging in scanning transmission electron microscopy (STEM). In STEM-ADF imaging with a small convergence angle, crystal tilt causes an artifact such as a shift of the bright spots corresponding to atomic columns. The displacement of the spots in ADF images differs for each atomic column, resulting in the breakdown of the incoherent imaging approximation...
August 2012: Journal of Electron Microscopy
Hironobu Yanagisawa, Kazuto Hoshi, Yukiyo Asawa, Sadakazu Ejiri, Kozo Sato, Hidehiro Ozawa
During the repair of articular cartilage, type I collagen (COL1)-based fibrous tissues change into a mixture of COL1 and type II collagen (COL2) and finally form hyaline cartilaginous tissues consisting of COL2. In order to elucidate the changes that occur in the matrix during cartilage repair and the roles of fibroblasts and chondrocytes in this process, we generated a minimal cartilage defect model that could be spontaneously repaired. Defects of 0.3 mm were created on the patellofemoral articular cartilage of rats using an Er:YAG laser and were observed histologically, ultrastructurally and histochemically...
August 2012: Journal of Electron Microscopy
Yuko Fukunaga, Ai Higashihara, Yuri Nishino, Takuo Yasunaga, Mingyue Jin, Atsuo Miyazawa
A cadmium-binding, genetically encoded protein tag, consisting of three repeats of metallothionein (3MT), can be used in electron microscopy for the visualization of multimeric- but not monomeric-tagged proteins due to insufficient electron density in monomeric proteins. Here, we present a technique for detecting monomeric 3MT-tagged green fluorescent protein (GFP-3MT) using a platinum compound to intensify the electron density. Substitution of cadmium by platinum as a result of incubating purified cadmium-binding 3MT-tagged GFP (GFP-Cd-3MT) with cis-diamminedichloroplatinum(II) (cisDDP) was assessed by a UV absorption band centered at 284 nm thereby indicating platinum-sulfhydryl bonds...
August 2012: Journal of Electron Microscopy
Tomoharu Tokunaga, Takashi Narushima, Tetsu Yonezawa, Takayuki Sudo, Shuichi Okubo, Shigeyuki Komatsubara, Katsuhiro Sasaki, Takahisa Yamamoto
The temperature distribution on a centre-holed thin foil of molybdenum, used as a sample and heated using a sample-heating holder for electron microscopy, was measured using an infrared thermal camera. The temperature on the heated foil area located near the heating stage of the heating holder is almost equal to the temperature on the heating stage. However, during the measurement of the temperature at the edge of the hole of the foil located farthest from the heating stage, a drop in temperature should be taken into consideration; however, so far, no method has been developed to locally measure the temperature distribution on the heated sample...
August 2012: Journal of Electron Microscopy
Toshie Yaguchi, Takashi Kanemura, Takahiro Shimizu, Daichi Imamura, Akira Watabe, Takeo Kamino
To clarify the influence of moisture on the structural changes of heated nano materials, in situ high temperature transmission electron microscopy (TEM) has been carried out using a conventional analytical TEM combined with a gas injection-specimen heating holder. Air with high moisture content, above 94% relative humidity (RH), from a humidifier was directly injected onto the heated platinum catalyst dispersed on carbon black (Pt/CB), and the morphological changes of the specimens were observed at high magnification dynamically...
August 2012: Journal of Electron Microscopy
Hwang Su Kim, Zaoli Zhang, Ute Kaiser
This report is an extension of the study for structural imaging of 5-6 nm thick β-Si(3)N(4) [0001] crystal with a spherical aberration corrected transmission electron microscope by Zhang and Kaiser [2009. Structure imaging of β-Si(3)N(4) by spherical aberration-corrected high-resolution transmission electron microscopy. Ultramicroscopy 109, 1114-1120]. In this work, a local symmetry breaking with an uneven resolution of dumbbells in the six-membered rings revealed in the reported images in the study of Zhang and Kaiser has been analyzed in detail...
June 2012: Journal of Electron Microscopy
Xiaobin Zhang, Masaki Takeguchi, Ayako Hashimoto, Kazutaka Mitsuishi, Peng Wang, Peter D Nellist, Angus I Kirkland, Meguru Tezuka, Masayuki Shimojo
Optical sectioning using scanning confocal electron microscopy (SCEM) is a new three-dimensional (3D) imaging technique which promises improved depth resolution, particularly for laterally extended objects. Using a stage-scanning system to move the specimen in three dimensions, two-dimensional (2D) images sliced from any plane in XYZ space can be obtained in shorter acquisition times than those required for conventional electron tomography. In this paper, a double aberration-corrected SCEM used in annular dark-field mode was used to observe the 3D structure of SiO(2) hollow spheres fabricated by a carbon template method...
June 2012: Journal of Electron Microscopy
Yoshifumi Oshima
Metal contacts are regarded as key elements of nanometer-scale electronics. Since gold contacts show quantized conductance even at room temperature, much effort has been devoted to understand their conductance behavior on the nanoscale. However, gold contacts do not always show quantized conductance steps during their thinning process, the reason for which has been an open question. Thus, it is necessary to investigate the relationship between the atomic structure and conductance of gold contacts. We developed a custom-made scanning tunneling microscope combined with an ultra-high vacuum transmission electron microscope to clarify the structural dependence of conductance quantization in gold contacts...
June 2012: Journal of Electron Microscopy
Mikiko Nitta, Yosuke Shida, Hitoshi Okada, Masako Osumi, Wataru Ogasawara
The filamentous fungus Trichoderma reesei which is known to secrete high amounts of cellulolytic enzymes was found to produce a massive amount of fibrous material at the outer surface of the cell wall as observed by ultrahigh-resolution low-voltage scanning electron microscopy. Using transmission electron microscopy, the cell wall ornamentation of the hyper-cellulosic mutant PC-3-7 was found to be less massive and much thinner than for QM9414. A significant amount of fibrous material was produced in Avicel-grown cultures that were less abundant in glucose-grown cultures and Avicel was occasionally found entangled within the cell wall-associated fibrous layer...
June 2012: Journal of Electron Microscopy
Koh Saitoh, Yuya Hasegawa, Nobuo Tanaka, Masaya Uchida
We report the production of electron vortex beams carrying large orbital angular momentum (OAM) using micro-fabricated spiral zone plates. A series of the spherical waves, focussing onto different positions along the propagating direction of the electron beam, were observed. The nth order vortex beam has an OAM n times larger than that of the first-order vortex beam. We observed an electron vortex with an OAM up to in a high-order diffracted wave. A linear dependence of the diameter of the vortex beam on the OAM was observed, being consistent to numerical simulations...
June 2012: Journal of Electron Microscopy
Kyoko Matoba, Junichi Takagi, Takuo Yasunaga, Hiroshi Jinnai, Kenji Iwasaki
Alignment of projection images in tomographic reconstruction is a critical process that governs the quality of the reconstructed three-dimensional (3D) image. The most popular alignment method is the marker-based alignment, which typically uses colloidal gold particles added to the specimen (called fiducial markers) to calculate the coordinates of each projection image in the tilt series. This method, however, is not effective when each image contains only a small number of fiducial markers. Therefore, of all the parameters required for alignment, we focussed on the tilt angle and attempted to gage it directly in order to examine whether the acquired angle is accurate enough to perform tomographic reconstruction...
June 2012: Journal of Electron Microscopy
Zheng Hua, Consolato Sergi, Patrick N Nation, Pamela R Wizzard, Ron O Ball, Paul B Pencharz, Justine M Turner, Paul W Wales
This study was designed to evaluate liver disease in neonatal piglets with surgical short bowel syndrome causing intestinal failure with partial parenteral nutrition dependence. The short bowel piglets had 75% surgical resection of distal small intestine, including all ileum and cecum, and were compared with sham controls, without resection, and to healthy sow-reared controls. After 18 days of combined parenteral and enteral nutrition in short bowel and sham piglets, liver tissue was collected for quantitative and semi-quantitative histological and ultrastructural evaluation...
June 2012: Journal of Electron Microscopy
Kenta Yoshida, Alexander Bright, Nobuo Tanaka
We study in situ behavior of platinum single atoms on amorphous carbon (a-carbon) using a spherical aberration-corrected transmission electron microscope (AC-TEM). Diffusion of single atoms, bi-atoms, clusters (<1 nm) and nanoparticles (<3 nm) was recorded in the same image with a time resolution of 1 s, and such diffusion matches the expected mechanism of Ostwald ripening, which was seen on these samples. In situ AC-TEM shows promise for dynamical observation of single atom diffusion, which is important for understanding nanosized catalysts and ceramic sintering processes...
April 2012: Journal of Electron Microscopy
Tsuneyuki Yamamoto, Tomoka Hasegawa, Muneteru Sasaki, Hiromi Hongo, Chihiro Tabata, Zhusheng Liu, Minqi Li, Norio Amizuka
This study was designed to elucidate details of the structure and formation process of the alternate lamellar pattern known to exist in lamellar bone. For this purpose, we examined basic internal lamellae in femurs of young rats by transmission and scanning electron microscopy, the latter employing two different macerations with NaOH at concentrations of 10 and 24%. Observations after the maceration with 10% NaOH showed that the regular and periodic rotation of collagen fibrils caused an alternation between two types of lamellae: one consisting of transversely and nearly transversely cut fibrils, and the other consisting of longitudinally and nearly longitudinally cut fibrils...
April 2012: Journal of Electron Microscopy
Pilar Vigil, Ana María Salgado, Manuel E Cortés
The oviduct is an important organ for successful mammalian reproduction. In this work, human oviducts were inseminated and their explants analyzed using scanning electron microscopy in order to study, at a finer ultrastructual level, the interaction between spermatozoon and oviduct in vitro. Results show unequivocally a spermatozoon tightly attached through the acrosomal region of its head to several cilia of the human tubal epithelial cells. This finding proves that spermatozoa do indeed adhere to the endosalpinx, a fact of utmost relevance for the physiology of the reproductive process, since it supports the idea of a spermatozoa reservoir being formed in the oviduct, which is also briefly discussed...
April 2012: Journal of Electron Microscopy
Hyun-Wook Kim, Seung Hak Oh, Ji-Woong Kim, Bongki Cho, In Sung Park, Woong Sun, Im Joo Rhyu
Mitochondria in all eukaryotes are essential organelles responsible for adenosine triphosphate synthesis, calcium homeostasis and steroidogenesis. Because the structure and distribution of mitochondria are highly diverse depending on their function and cellular conditions, it is important to develop a rapid and accurate method to assess their morphology. In this study, we visualize whole mitochondria in cultured cells using high-voltage electron microscopy (HVEM). Compared with conventional transmission electron microscopic approaches, the present method does not require thin sectioning and thus requires less time for image acquisition and processing...
April 2012: Journal of Electron Microscopy
Daisuke Koga, Masato Nakajima, Tatsuo Ushiki
Scanning electron microscopy (SEM) using osmium-maceration methods has been used for analyzing the three-dimensional structure of cell organelles in tissue samples, but it has been quite difficult to observe free and cultured cells with this technique. The present study was performed to develop a method that can be applied to free and cultured cells for SEM studies of intracellular structures after osmium maceration. The method was also applied to light microscopy (LM) and to transmission electron microscopy (TEM)...
April 2012: Journal of Electron Microscopy
Hai-Bo Zhang, Wei-Qin Li, Meng Cao
In this study, based on a comprehensive numerical simulation of self-consistent charging, we investigate the formation, evolution and influencing factors of space charge distributions for a grounded insulating thin film of SiO(2) negatively charged by a keV non-penetrating focused electron beam. The simulated space charge presents first positive distributions and then negative ones along both the radial and depth directions because of the difference between electron and hole transports. The variations in distribution occur within a range of the minimum potential acting as a potential barrier for carrier transport...
April 2012: Journal of Electron Microscopy
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