Microscopy (Oxford, England)最新文献_第2页

Precise positional alignment of atom-resolved HAADF images of heteroepitaxial interface with low signal-to-noise ratio. 低信噪比异质外延界面原子分辨 HAADF 图像的精确定位。

Microscopy (Oxford, England) Pub Date : 2025-01-30 DOI: 10.1093/jmicro/dfae038

Kohei Aso, Yoshifumi Oshima

引用次数: 0

Development of a localized surface plasmon-enhanced electron beam-pumped nanoscale light source for electron beam excitation-assisted optical microscopy. 开发用于电子束激发辅助光学显微镜的局部表面等离子体增强电子束泵浦纳米级光源。

Microscopy (Oxford, England) Pub Date : 2025-01-30 DOI: 10.1093/jmicro/dfae043

Atsushi Nakamura, Shunpei Shiba, Kei Hosomi, Atsushi Ono, Yoshimasa Kawata, Wataru Inami

引用次数: 0

Nanoscale visualization of crack tips inside molten corium-concrete interaction debris using 3D-FIB-SEM with multiphase positional misalignment correction. 利用具有多相位置偏差校正功能的 3D-FIB-SEM 对熔融铈-混凝土相互作用碎片内部的裂缝尖端进行纳米级可视化。

Microscopy (Oxford, England) Pub Date : 2025-01-25 DOI: 10.1093/jmicro/dfaf005

Hotaka Miyata, Kenta Yoshida, Kenji Konashi, Yufeng Du, Toru Kitagaki, Takahisa Shobu, Yusuke Shimada

{"title":"Nanoscale visualization of crack tips inside molten corium-concrete interaction debris using 3D-FIB-SEM with multiphase positional misalignment correction.","authors":"Hotaka Miyata, Kenta Yoshida, Kenji Konashi, Yufeng Du, Toru Kitagaki, Takahisa Shobu, Yusuke Shimada","doi":"10.1093/jmicro/dfaf005","DOIUrl":"https://doi.org/10.1093/jmicro/dfaf005","url":null,"abstract":"Characterizing molten corium-concrete interaction (MCCI) fuel debris in Fukushima reactors is essential to develop efficient methods for its removal. To enhance the accuracy of microscopic observation and focused ion beam (FIB) microsampling of MCCI fuel debris, we developed a three-dimentional FIB scanning electron microscopy (SEM) technique with a multiphase positional misalignment (MPPM) correction method. This system automatically aligns voxel positions, corrects contrast, and removes artifacts from a series of over 500 SEM images. The MPPM correction method, which focuses on time-modulated contrast, considerably reduces charge-up artifacts in glass phases, enabling 3D morphological observation and analytical transmission electron microscopy of crack tips in two types of MCCI debris at the 3D/nanoscale for the first time. In the Fe-ZrSiO4-based debris, metallic balls composed of Fe, Cr2O3, and ZrO2 with dimples on the surface of about 2-58 µm in diameter were observed at the crack tips. In the (Zr, U)SiO4 based debris, a core-shell structure composed of a (U, Zr)O2 core with a diameter of about 1-5 μm and a (Zr, U)SiO4 shell with a diameter of about 2-9 μm in complex molten corium-concrete interaction fuel debris at the crack tips.","PeriodicalId":74193,"journal":{"name":"Microscopy (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Self-absorption effect in soft X-ray emission spectra utilized for bandgap evaluation of semiconductors.

Microscopy (Oxford, England) Pub Date : 2025-01-24 DOI: 10.1093/jmicro/dfaf008

Masami Terauchi, Yohei K Sato

{"title":"Self-absorption effect in soft X-ray emission spectra utilized for bandgap evaluation of semiconductors.","authors":"Masami Terauchi, Yohei K Sato","doi":"10.1093/jmicro/dfaf008","DOIUrl":"https://doi.org/10.1093/jmicro/dfaf008","url":null,"abstract":"The self-absorption effects observed in the background intensity just above the Si L-emission spectra of Si and β-Si3N4, and the C K-emission spectra of diamond and graphite were examined. Based on comparisons with reported results, the energy positions of absorption edges-representing the bottom of conduction bands (CB)-were assigned. The self-absorption profiles in the background intensities were consistent with previously reported data. The simultaneous observation of the edges of the valence bands (VB) and CB allowed the determination of a bandgap energy of 1.1 eV for Si, which agrees with the indirect bandgap energy of Si. For β-Si3N4, the bandgap energy was evaluated as 5.1 eV. For diamond, the edge positions were matched with reported values, and the bandgap energy was calculated to be 5.0 eV, slightly smaller than the optical gap of 5.5 eV. These observations suggest that both edge observation can be expected for semiconductors in principle. On the other hand, C K-emission spectrum of graphite, a semimetal also showed an edge structure, which was assigned to the self-absorption edge due to the transitions from 1s to σ* antibonding state of sp2 bonding.","PeriodicalId":74193,"journal":{"name":"Microscopy (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143030356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Noise reduction of low-dose electron holograms using the wavelet hidden Markov model.

Microscopy (Oxford, England) Pub Date : 2025-01-22 DOI: 10.1093/jmicro/dfaf007

Yuto Tomita, Yoshihiro Midoh, Takehiro Tamaoka, Yasukazu Murakami

{"title":"Noise reduction of low-dose electron holograms using the wavelet hidden Markov model.","authors":"Yuto Tomita, Yoshihiro Midoh, Takehiro Tamaoka, Yasukazu Murakami","doi":"10.1093/jmicro/dfaf007","DOIUrl":"https://doi.org/10.1093/jmicro/dfaf007","url":null,"abstract":"The precision in electron holography studies on electrostatic and magnetic fields depends on the image quality of an electron hologram. Enhancing the image quality of electron holograms is essential for the comprehensive analysis of weak electromagnetic fields; however, extended electron beam irradiation can lead to undesirable radiation damage and contamination. Recent studies have demonstrated that noise reduction using the wavelet hidden Markov model (WHMM) can improve the precision of phase analysis for limited thin-foiled crystals. In this study, we examine the effects of WHMM-based denoising on the electron holography data of weakly charged nanoparticles collected under low-electron-dose conditions. The results indicate that effective noise reduction with the WHMM allows for a reduction in the magnitude of the electron dose by approximately half relative to data collection without WHMM denoising, while maintaining the same level of the charge determination precision: less than one elementary charge. Notably, at a low electron dose of 0.40 e-/pixel, WHMM denoising enables the clear visualization of a weak stray electric field outside a charged latex sphere. This method offers significant advantages for electron holography studies of electron-beam-sensitive materials requiring minimal time for electron exposure.","PeriodicalId":74193,"journal":{"name":"Microscopy (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A guide to CNN-based dense segmentation of neuronal EM images. 基于cnn的神经元EM图像密集分割指南。

Microscopy (Oxford, England) Pub Date : 2025-01-13 DOI: 10.1093/jmicro/dfaf002

Hidetoshi Urakubo

{"title":"A guide to CNN-based dense segmentation of neuronal EM images.","authors":"Hidetoshi Urakubo","doi":"10.1093/jmicro/dfaf002","DOIUrl":"https://doi.org/10.1093/jmicro/dfaf002","url":null,"abstract":"Large-scale reconstitution of neuronal circuits from volumetric electron microscopy images is a remarkable research goal in neuroanatomy. However, the large-scale reconstruction is a result of automatic segmentation using convolutional neural networks (CNNs), which is still challenging for general researchers to perform. This review focuses on two representative CNNs for dense neuronal segmentation: flood-filling networks (FFN) and local shape descriptors (LSD)-predicting U-Net (LSD network). It outlines their basic mechanisms, requirements, and output segmentation using author's example segmentation. The FFN excels in segmenting long axons, and the LSD network is adept at segmenting myelinated axons. The choice between FFN and LSD depends on the target, as neither is universally superior. A common limitation of FFN and LSD is the easy detachment of thin spines from parent dendrites, which is fundamentally unavoidable. The author also introduces CNNs proposed to mitigate this issue. As CNN-based automated segmentation can take months, researchers need to be aware of the selection of an appropriate CNN, required computer resources, and fundamental limitations. This review serves as a guide for such dense neuronal segmentation.","PeriodicalId":74193,"journal":{"name":"Microscopy (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142973854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Efficient Data Sampling Scheme to Reduce Acquisition Time in Statistical ALCHEMI. 统计炼金术中减少采集时间的有效数据采样方案。

Microscopy (Oxford, England) Pub Date : 2025-01-13 DOI: 10.1093/jmicro/dfaf004

Akimitsu Ishizuka, Masahiro Ohtsuka, Shunsuke Muto

{"title":"Efficient Data Sampling Scheme to Reduce Acquisition Time in Statistical ALCHEMI.","authors":"Akimitsu Ishizuka, Masahiro Ohtsuka, Shunsuke Muto","doi":"10.1093/jmicro/dfaf004","DOIUrl":"https://doi.org/10.1093/jmicro/dfaf004","url":null,"abstract":"The distribution of dopants in host crystals significantly influences the chemical and electronic properties of materials. Therefore, determining this distribution is crucial for optimizing material performance. The previously developed statistical ALCHEMI (St-ALCHEMI), an extension of the atom-location by channeling-enhanced microanalysis (ALCHEMI) technique, utilizes variations in electron channeling based on the beam direction relative to the crystal orientation. It statistically analyzes spectra collected across multiple beam directions. However, the total experimental time can be extensive, particularly for low dopant concentrations, where typical experiments can span several hours. In this study, we propose a scheme based on efficient sampling point selection that reduces the experimental time required while maintaining accuracy. Guidelines for selecting beam directions were derived from theoretical and experimental analyses of data redundancy. The strategies include choosing directions that exhibit greater variances in the host ionization channeling patterns and lower correlation coefficients between them. Additionally, an edge detection scheme using the dual tree complex wavelet transform, applied to electron channeling patterns, is proposed to significantly reduce measurement time. Our findings suggest that effective sampling can reduce experimental duration by at least two orders of magnitude without compromising accuracy. Implementing the proposed guidelines shortens total measurement times, minimizes electron irradiation damage, and improves S/N ratio through extended data acquisition per tilt.","PeriodicalId":74193,"journal":{"name":"Microscopy (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142973856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Encapsulation, vacuolation, and phagocytosis of the opportunistic fungal pathogen Cryptococcus in the liver of an immunocompetent host. 机会性真菌病原体隐球菌在免疫能力强的宿主肝脏中的包封、空泡化和吞噬作用。

Microscopy (Oxford, England) Pub Date : 2025-01-08 DOI: 10.1093/jmicro/dfaf003

Chul Jong Yoon, Je Geun Chi, Ki Woo Kim

{"title":"Encapsulation, vacuolation, and phagocytosis of the opportunistic fungal pathogen Cryptococcus in the liver of an immunocompetent host.","authors":"Chul Jong Yoon, Je Geun Chi, Ki Woo Kim","doi":"10.1093/jmicro/dfaf003","DOIUrl":"https://doi.org/10.1093/jmicro/dfaf003","url":null,"abstract":"The cellular characteristics of the opportunistic fungal pathogen Cryptococcus species were investigated in the infected liver of an immunocompetent host using transmission electron microscopy (TEM). With no records of immunodeficiency, the 3-year-old female patient displayed a high-grade fever, lethargy, and increasing jaundice. TEM analysis revealed the presence of round yeast cells in the patient's liver. These fungal yeast cells exhibited an array of cellular events in the host's liver: (i) the formation of polysaccharide capsules outside the cell wall, (ii) vacuolation in the cytoplasm, and (iii) phagocytosis by Kupffer cells. The yeast cells were surrounded by electron-transparent polysaccharide capsules (approximately 5 μm thick). A series of yeast vacuolations were observed at different stages of cell development. As vacuoles occupied the cytoplasm of yeast cells, the polysaccharide capsules were thinner and more electron-dense than those of intact yeast cells. Certain yeast cells were phagocytosed by Kupffer cells through the budding scars or discontinued regions in the cell walls. These observations suggested that the patient was suffering from liver cryptococcosis. This study provides insights into the behavior of opportunistic fungal pathogens in the livers of immunocompetent patients.","PeriodicalId":74193,"journal":{"name":"Microscopy (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142959779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observation of morphological changes in silicon-based negative-electrode active materials during charging/discharging using operando scanning electron microscopy. 用operando扫描电镜观察硅基负极活性材料在充放电过程中的形态变化。

Microscopy (Oxford, England) Pub Date : 2024-12-30 DOI: 10.1093/jmicro/dfae060

Takako Kurosawa, Noriaki Fukumoto, Kaoru Inoue, Emiko Igaki

引用次数: 0

Basic properties of solidified organic liquids at a cryogenic temperature for electron microscopic visualization and sample preparation of dispersion systems. 低温下固化有机液体的基本性质，用于电镜观察和分散体系的样品制备。

Microscopy (Oxford, England) Pub Date : 2024-12-30 DOI: 10.1093/jmicro/dfae059

Satoshi Okada

{"title":"Basic properties of solidified organic liquids at a cryogenic temperature for electron microscopic visualization and sample preparation of dispersion systems.","authors":"Satoshi Okada","doi":"10.1093/jmicro/dfae059","DOIUrl":"https://doi.org/10.1093/jmicro/dfae059","url":null,"abstract":"It is challenging to image structures in liquids for electron microscopy (EM); thus, low-temperature imaging has been developed, initially for aqueous systems. Organic liquids (OLs) are widely used as dispersants, although their cryogenic EM (cryo-EM) imaging is less common than that of aqueous systems. This is because the basic properties (e.g., vapor pressure, density, and amorphousness) of OL in the solid state have not been extensively investigated, preventing the determination of whether or not the observed structure is free from artifacts. Herein, I summarized physical data related to the phase change, and the solid density at 77 K and sublimation speed for some OLs were measured independently, to discuss the applicability of OLs for cryo-EM. Among various OL properties, the sublimation temperature, pressure, and rate, and crystallinity are important for cryo-EM. The sublimation-related properties are used to judge whether the OL is stable during storage, observation, and sample preparation such as etching. These properties were calculated, and the calculated sublimation speed matched with that measured by cryo-SEM movie imaging. Crystallinity was estimated using the difference between the extrapolated temperature-dependent liquid density and the solid density of frozen OLs measured in liquid nitrogen. Artifacts observed upon freezing were exemplified by focused ion beam cross-sections of OL-in-water emulsions, and cracks, voids, and wrinkles are found in the OL phase at a large shrinkage ratio. The study findings show that the applicability of OLs largely differs for structural isomers and that appropriate OLs are required for the cryo-EM imaging of nonaqueous systems.","PeriodicalId":74193,"journal":{"name":"Microscopy (Oxford, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142959854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0