The three-dimensional (3D) anatomical structure of living organisms is intrinsically linked to their functions, yet modern life sciences have not fully explored this aspect. Recently, the combination of efficient tissue clearing techniques and light-sheet fluorescence microscopy (LSFM) for rapid 3D imaging has improved access to 3D spatial information in biological systems. This technology has found applications in various fields, including neuroscience, cancer research, and clinical histopathology, leading to significant insights. It allows imaging of entire organs or even whole bodies of animals and humans at multiple scales. Moreover, it enables a form of spatial omics by capturing and analyzing cellome information, which represents the complete spatial organization of cells. While current 3D imaging of cleared tissues has limitations in obtaining sufficient molecular information, emerging technologies such as multi-round tissue staining and super-multicolor imaging are expected to address these constraints. 3D imaging using tissue clearing and light-sheet microscopy thus offers a valuable research tool in the current and future life sciences for acquiring and analyzing large-scale biological spatial information.

X-ray microscopy using computed tomography (CT) is an excellent three-dimensional imaging instrument. Three-dimensional X-ray microscopy (3DXRM) is a nondestructive imaging technique used to inspect internal and external structures in units of submicrometers or less. The 3DXRM, although attractive, is mostly used as an observation instrument and is limited as a measurement system in quantitative evaluation and quality control. Calibration is required for use in measurement systems such as coordinate measurement systems, and specific standard samples and evaluation procedures are needed. The certified values of the standard samples must ideally be traceable to the International System of Units (SI). In the 3DXRM measurement system, line structures (LSs) are fabricated as prototype standard samples to conduct magnification calibration. In this study, we evaluated the LS intervals using calibrated cross-sectional scanning electron microscopy (SEM). A comparison of the evaluation results between SEM and 3DXRM for the LS intervals provided the magnification calibration factor for 3DXRM and validated the LSs, whereby the interval methods and feasibility of constructing an SI traceability system were evaluated using the calibrated SEM. Consequently, a magnification calibration factor of 1.01 was obtained for 3DXRM based on the intervals of the LSs evaluated by SEM. A possible route for realizing SI-traceable magnification calibration of 3DXRM has been presented.

We have demonstrated localized surface plasmon (LSP)-enhanced cathodoluminescence (CL) from an atomic layer deposition (ALD)-grown Al2O3/ZnO/Al2O3 heterostructure to develop a bright nanometer-scale light source for an electron beam excitation-assisted (EXA) optical microscope. Three types of metals, Ag, Al, and Au, were compared, and an 181-fold enhancement of CL emission was achieved with Ag nanoparticles (NPs), with the plasmon resonance wavelength close to the emission wavelength energy of ZnO. The enhanced emission is plausibly attributed to LSP/exciton coupling. However, it is also attributed to an increase in coupling efficiency with penetration depth and also to an increase in light extraction efficiency by grading the refractive indices at the heterostructure.

The spatial coherence and the axial brightness of a cold field emission gun, a Schottky field emission gun and a $\mathrm{LaB}_6$ thermionic gun are precisely measured. By analyzing the Airy pattern from a selected area aperture, various parameters including the spatial coherence length are determined. Using the determined coherence length, the axial brightness of the field emission guns is estimated using the equation which we previously derived based on the discussion of the Wigner function of an electron beam. We also make some extensions in the method to be applicable to the measurements of the thermionic gun, which has anisotropic intensity distribution in most case unlike the field emission guns. Not conventional average brightness but the axial brightness measured for the three kinds of emitters are compared accurately and precisely without influenced by the measurement conditions.

Cell membrane structures are supramolecular complexes that require the ordered assembly of membrane proteins and lipids. The morphology of various cell adhesion structures in multicellular organisms, such as those between epithelial cells, neural synapse and immune synapses, was initially described through electron microscopic analyses. Subsequent studies aimed to catalog their constituent proteins, which encompass transmembrane cell adhesion molecules, cytoskeletal proteins, and scaffolding proteins that bind the two components. However, the diversity of plasma membrane lipids and their significance in the organization of cell adhesion structures were underappreciated until recently. It is now understood that phase separation of lipids and liquid-liquid phase separation of proteins are important driving forces for such self-assembly. In this review, we summarize recent findings on the role of lipids as scaffolds for supramolecular complexes, using tight junctions in epithelial cells as an example.

A new configuration for near-field ptychography using a full-field illumination with a structured electron beam is proposed. A structured electron beam illuminating the entire field of view is scanned over the specimen, and a series of in-line holograms formed in the near-field region below the specimen are collected. The structured beam is generated by a conductive film with random openings, which ensures high stability and coherence of the beam. Observation in the near-field region reduces the beam concentration that occurs in the far-field region, which contributes to accurate recording of the beam intensity with a finite dynamic range of the detectors. The use of full-field illumination prevents the accumulation of errors caused by concatenating the local structures, which is the method used in conventional reconstruction. Since all holograms are obtained from the entire field of view, they have uniform multiplicity in terms of specimen information within the field of view. This contributes to robust and efficient reconstruction for a large field of view. The proposed method was tested using both simulated and experimental holograms. For the simulated holograms, the reconstruction of the specimen transmission function was achieved with an error less than 1/3485 of the wavelength. The method was further validated using experimental holograms obtained from MgO particles. The reconstructed phase transmission function of the specimen was consistent with the specimen structure and was equivalent to a mean inner potential of V on the MgO particle, which is in close agreement with previously reported values.

Adapting to environmental changes and formulating behavioral strategies are central to the nervous system, with the prefrontal cortex being crucial. Chronic stress impacts this region, leading to disorders including major depression. This review discusses the roles for prefrontal cortex and the effects of stress, highlighting similarities and differences between human/primates and rodent brains. Notably, the rodent medial prefrontal cortex is analogous to the human subgenual anterior cingulate cortex in terms of emotional regulation, sharing similarities in cytoarchitecture and circuitry, while also performing cognitive functions similar to the human dorsolateral prefrontal cortex. It has been shown that chronic stress induces atrophic changes in the rodent mPFC, which mirrors the atrophy observed in the subgenual anterior cingulate cortex and dorsolateral prefrontal cortex of depression patients. However, the precise alterations in neural circuitry due to chronic stress are yet to be fully unraveled. The use of advanced imaging techniques, particularly volume electron microscopy, is emphasized as critical for the detailed examination of synaptic changes, providing a deeper understanding of stress and depression at the molecular, cellular and circuit levels. This approach offers invaluable insights into the alterations in neuronal circuits within the medial prefrontal cortex caused by chronic stress, significantly enriching our understanding of stress and depression pathologies.

Sandwich freezing is a method of rapid freezing by sandwiching specimens between two copper disks and has been used for observing exquisite close-to-native ultrastructure of living yeast and bacteria. Recently, this method has been found to be useful for preserving cell images of glutaraldehyde-fixed cultured cells, as well as animal and human tissues. In the present study, this method was applied to observe the fine structure of living Arabidopsis plant tissues and was found to achieve excellent ultrastructural preservation of cells and tissues. This is the first report of applying the sandwich freezing method to observe plant tissues.