Microscopy

List of Papers (Total 212)

Enhanced detection efficiency of genetically encoded tag allows the visualization of monomeric proteins by electron microscopy

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...

Production of electron vortex beams carrying large orbital angular momentum using spiral zone plates

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...

Three-dimensional reconstructions of electrostatic potential distributions with 1.5-nm resolution using off-axis electron holography

Three-dimensional (3D) reconstruction experiments were carried out by observing high-resolution 3D electrostatic potential distributions of Pt nanoparticles using off-axis electron holographic tomography. These Pt nanoparticles were mounted on the surfaces of amorphous silicon pillars. In order to realize high-resolution observation, we developed a mechanically stable 3D specimen...

Twin-electron biprism

In order to obtain a large deflection angle without increasing the applied voltage to an electron biprism, we have developed a ‘twin-electron biprism’ (TBP), which is composed of two filament electrodes and a pair of ground plates. The observed interference-fringe spacing revealed that the deflection angle created by a TBP was about twice larger than that by a ‘conventional...

Vortex beams for atomic resolution dichroism

Vortex beams carrying orbital angular momentum have been produced recently with electron microscopy by interfering an incident electron beam with a grid containing dislocations. Here, we present an analytical derivation of vortex wave functions in reciprocal and real space. We outline their mathematical and physical properties and describe the conditions under which vortex beams...

New views of materials through aberration-corrected scanning transmission electron microscopy

The successful correction of third-order and, more recently, fifth-order aberrations has enormously enhanced the capabilities of the scanning transmission electron microscope (STEM), by not only achieving record resolution, but also allowing near 100% efficiency for electron energy loss spectroscopy, and higher currents for two-dimensional spectrum imaging. These advances have...

Adaptation of the Tokuyasu method for the ultrastructural study and immunogold labelling of filamentous fungi

The study of filamentous fungi is fundamental not only to extend their biotechnological applications, but also to develop new drugs to fight pathological species. Morphological analyses are particularly relevant when investigating their development and differentiation. The need to maintain the orientation of hyphae and the presence of a cell wall, which hampers the sample...

Novel nanofibrous scaffolds for water filtration with bacteria and virus removal capability

We demonstrate a new class of composite fibrous membranes, consisting of an ultra-fine cellulose nanofibrous network infused into an electrospun polyacrylonitrile (PAN) nanofibrous scaffold on a melt-blown polyethylene terephthalate (PET) non-woven substrate for water purification. Depending on the infusion process and the ultra-fine cellulose nanofibers (UFCNs) used [e.g...

Estimation of wave fields of incident beams in a transmission electron microscope by using a small selected-area aperture

The direction of an electron beam in a nanometer-sized area is measured directly by utilizing a selected-area aperture. By the measurements at several areas in a beam, the wavefront curvature and thus the defocus value of the beam are detected. From the defocus value, the wave field at the specimen plane is also reproduced in consideration of the influences of the condenser...

Direct imaging of pH1N1 2009 influenza virus replication in alveolar pneumocytes in fatal cases by transmission electron microscopy

Human influenza virus pandemics constitute a major global public health issue. Although studies on autopsy specimens from the recent pandemic by the 2009 influenza A (H1N1) virus have revealed a broad spectrum of pathologic findings, direct electron microscopic studies of the lung tissue from influenza fatalities are few. In this study, we examined five well-preserved pulmonary...

A low fluence Q-switched Nd:YAG laser modifies the 3D structure of melanocyte and ultrastructure of melanosome by subcellular-selective photothermolysis

Laser treatment using low fluence for melasma was previously introduced to overcome postinflammatory hypermelanosis after Q-switched laser therapy. However, research on the mechanism of this treatment is very limited. In this study, a collimated low fluence 1064 nm Q-switched Nd:YAG laser with a pulse width of <7 ns was applied using top-hat beam mode. The aim of this study was...

Dengue virus-induced autophagosomes and changes in endomembrane ultrastructure imaged by electron tomography and whole-mount grid-cell culture techniques

The biogenesis events and formation of dengue virus (DENV) in the infected host cells remain incompletely understood. In the present study, we examined the ultrastructural changes associated with DENV-2 replication in three susceptible host cells, C6/36, Vero and SK Hep1, a cell line of human endothelial origin, using transmission electron microscopy, whole-mount grid-cell...

Development of wavelength-dispersive soft X-ray emission spectrometers for transmission electron microscopes—an introduction of valence electron spectroscopy for transmission electron microscopy

Two types of wavelength-dispersive soft X-ray spectrometers, a high-dispersion type and a conventional one, for transmission electron microscopes were constructed. Those spectrometers were used to study the electronic states of valence electrons (bonding electrons). Both spectrometers extended the acceptable energy regions to higher than 2000 eV. The best energy resolution of 0...