Amirafshar Moshtaghpour, Abner Velazco-Torrejon, Daniel Nicholls, Alex W Robinson, Angus I Kirkland, Nigel D Browning
{"title":"Diffusion distribution model for damage mitigation in scanning transmission electron microscopy.","authors":"Amirafshar Moshtaghpour, Abner Velazco-Torrejon, Daniel Nicholls, Alex W Robinson, Angus I Kirkland, Nigel D Browning","doi":"10.1111/jmi.13351","DOIUrl":"https://doi.org/10.1111/jmi.13351","url":null,"abstract":"<p><p>Despite the widespread use of Scanning Transmission Electron Microscopy (STEM) for observing the structure of materials at the atomic scale, a detailed understanding of some relevant electron beam damage mechanisms is limited. Recent reports suggest that certain types of damage can be modelled as a diffusion process and that the accumulation effects of this process must be kept low in order to reduce damage. We therefore develop an explicit mathematical formulation of spatiotemporal diffusion processes in STEM that take into account both instrument and sample parameters. Furthermore, our framework can aid the design of Diffusion Controlled Sampling (DCS) strategies using optimally selected probe positions in STEM, that constrain the cumulative diffusion distribution. Numerical simulations highlight the variability of the cumulative diffusion distribution for different experimental STEM configurations. These analytical and numerical frameworks can subsequently be used for careful design of 2- and 4-dimensional STEM experiments where beam damage is minimised.</p>","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142017749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafael Álvarez-Chimal, César Rodríguez-Cruz, Carlos Alvarez-Gayosso, Jesús A Arenas-Alatorre
{"title":"Study of ZnO nanoparticle-doped dental adhesives on enamels with fluorosis: Electron microscopy, elemental composition and shear bond strength analysis.","authors":"Rafael Álvarez-Chimal, César Rodríguez-Cruz, Carlos Alvarez-Gayosso, Jesús A Arenas-Alatorre","doi":"10.1111/jmi.13353","DOIUrl":"https://doi.org/10.1111/jmi.13353","url":null,"abstract":"<p><p>This study aimed to evaluate dental adhesives containing different concentrations of zinc oxide nanoparticles (ZnO-NPs) for their use in the treatment of dental fluorosis, observe the interaction of the adhesive on healthy enamel surfaces and with mild and moderate fluorosis, measure the adhesive strength and fluorosis, and determine the phosphorus (P) and calcium (Ca) content on these surfaces, as a reference for the potential use of this adhesive with ZnO-NPs for dental fluorosis treatment. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were used to characterise the ZnO-NPs and analyse the weight percentages of P and Ca in the enamel using X-ray energy dispersive spectroscopy (EDS) and the adhesive strength using a universal mechanical testing machine. FESEM characterisation revealed that the ZnO-NPs were less than 100 nm in size, with quasi-spherical and hexagonal prism shapes. The synthesis of the ZnO-NPs was confirmed by TEM, revealing their hexagonal crystalline structure. The adhesive strength by the universal mechanical testing machine showed that the adhesive with a 3% wt. concentration of ZnO-NPs was better in the three groups of teeth, showing higher adhesive strength in teeth with mild (15.15 MPa) and moderate (12.76 MPa) fluorosis surfaces, and was even higher than that in healthy teeth (9.65 MPa). EDS analysis showed that teeth with mild and moderate fluorosis had the highest weight percentages of P and Ca, but there were no statistically significant differences compared to healthy teeth and teeth treated with adhesives. Lay description: This study focused on testing a new dental adhesive containing small particles called ZnO nanoparticles (ZnO-NPs). This study aimed to demonstrate whether this adhesive with ZnO-NPs could be useful for treating dental fluorosis by improving its adhesion to teeth. One of the first objectives was to determine whether the dental adhesive could adhere better to teeth affected by mild or moderate fluorosis than to healthy teeth by measuring whether the levels of two important elements for healthy teeth, calcium (Ca) and phosphorus (P), were affected by the adhesive. The size and shape of the small particles and teeth with mild or moderate fluorosis were observed using scanning electron microscopy. The nanoparticles were small (< 100 nm) and had specific quasi-spherical and hexagonal prismatic shapes. More damage to the enamel was observed in teeth with mild or moderate fluorosis than in healthy teeth. The adhesive strength test demonstrated that the dental adhesive with 3% ZnO-NPs had the best adhesion on all healthy conditions of teeth. It was particularly effective in teeth with mild or moderate fluorosis. Finally, the evaluation of the levels of P and Ca on the enamel showed that teeth with fluorosis had higher levels of these elements, but using the dental adhesive with ZnO-NPs did not change the levels of these elements significantly because the ","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142017750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to “Comparison of holotomographic microscopy and coherence-controlled holographic microscopy”","authors":"","doi":"10.1111/jmi.13354","DOIUrl":"10.1111/jmi.13354","url":null,"abstract":"<p>Chvalova, V., Vomastek, T., & Grousl, T. (2024). Comparison of holotomographic microscopy and coherence-controlled holographic microscopy. <i>Journal of Microscopy</i>, <i>294</i>(1), 5–13. https://onlinelibrary.wiley.com/doi/10.1111/jmi.13260</p><p>In the Acknowledgements, the grant number “Ministry of Health project NU22-03-00197 (to TV)” was incorrect. This should have read: “Ministry of Health project NU23-03-00557 (to TV)”.</p><p>We apologise for this error.</p>","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jmi.13354","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142017748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An alignment algorithm using coherent twin boundaries as internal reference in 3D-EBSD.","authors":"Heng Li, Shuang Xia, Qin Bai, Tingguang Liu, Yong Zhang","doi":"10.1111/jmi.13352","DOIUrl":"https://doi.org/10.1111/jmi.13352","url":null,"abstract":"<p><p>A three-dimensional (3D) microstructural volume is reconstructed from a stack of two-dimensional sections which was obtained by serial sectioning coupled with electron back scattering diffraction (EBSD) mapping of a 316L austenitic stainless steel. A new alignment algorithm named linear translation by minimising the indicator (LTMI) is proposed to reduce the translational misalignments between adjacent sections by referencing to coherent twin boundaries which are flat and lying on {111} planes. The angular difference between the measured orientation of a flat twin boundary and that of the {111} plane is used as an indicator of the accuracy of the alignment operations. This indicator is minimised through linear translations of the centroids of triangular facets, which constitute grain boundaries at a distance not restricted by the in-plane step size of the EBSD maps. And hence the systematic trend in the translational misalignments can be effectively reduced. The LTMI alignment procedure proposed herein effectively corrects the misalignments remained by other methods on a 3D-EBSD data prepared using serial sectioning methods. The accuracy in distinguishing between coherent and incoherent twin boundaries is significantly improved.</p>","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141988183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analysis of the Ag M<sub>4,5</sub> EELS edge to study silver nanoparticle corrosion.","authors":"J C Brennan, D A MacLaren","doi":"10.1111/jmi.13348","DOIUrl":"https://doi.org/10.1111/jmi.13348","url":null,"abstract":"<p><p>Electron energy loss spectra collected from fresh and corroded silver nanoparticles are compared with those from a number of reference materials, focusing on the M<sub>4,5</sub> edge. Chemical shifts and changes in the energy loss near edge structure (ELNES) are described and found to be sufficient to distinguish metallic silver from chemically oxidised silver. The measurements, in conjunction with electron energy loss spectrum imaging, are used to assess the mechanisms for atmospheric corrosion of silver nanoparticles. We unambiguously assign the corrosion product under atmospheric conditions to be silver sulphide, but show the reaction process to be distinctly inhomogeneous, producing a variety of types of corroded particles. LAY DESCRIPTION: >Here, we use analytical electron microscopy to track the corrosion of silver nanoparticles and present chemical maps of the corrosion products. We show clear spectroscopic differences between metallic and corroded silver using the M<sub>4,5</sub> electron energy loss spectral feature, which is not commonly studied. Our study shows that corrosion is due to interactions with sulphur in the atmosphere; and the corrosion is not uniform, but appears to develop from specific points on the surface of the nanoparticles.</p>","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141902013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of reinforcement particle size on the corrosion and mechanical properties of spark plasma sintered aluminium matrix composites.","authors":"Behzad Sadeghi, Pasquale Cavaliere, Mohsen Sanayei","doi":"10.1111/jmi.13350","DOIUrl":"https://doi.org/10.1111/jmi.13350","url":null,"abstract":"<p><p>In this study, the effects of different sizes of reinforcing particles on the corrosion behaviour and mechanical properties of aluminium (Al)-based composites produced by spark plasma sintering (SPS) are analysed. In the study, the effects of SPS parameters, including electrical power, applied pressure and sintering temperature, on the consolidation process and microstructure evolution of the composite are closely investigated. The results reveal a nuanced relationship between the sintering conditions and the properties of the particles, which in turn determine the sintering dynamics and the formation of the microstructural features. The evaluation of mechanical properties indicates a remarkable influence of particle size distribution on the hardness of the composites, showing an initial improvement with the introduction of nanoparticles, followed by a slight decrease as the balance between nano- and micron-sized Al<sub>2</sub>O<sub>3</sub> particles shifts. A scanning electron microscopy (SEM) study demonstrates the influence of particle dimensions on the change of grain boundaries and the spatial arrangement of the composite matrix. Electrochemical experiments in a 0.1 M NaCl solution show a consistent corrosion potential (E<sub>corr</sub>) across all samples, while the current densities associated with corrosion (i<sub>corr</sub>) show considerable variation. The presence of nano-sized Al<sub>2</sub>O<sub>3</sub> particles was found to increase corrosion resistance, in contrast to the detrimental effects observed with larger microparticles. In particular, composites with a bimodal distribution of particle sizes showed a 3.5-fold increase in corrosion resistance compared to pure Al. The specific Al-2n8mAl<sub>2</sub>O<sub>3</sub> composite that exhibited active electrochemical properties at elevated potentials without a defined passivation range emphasises the significant role of particle size. This study draws attention to bimodal microstructures as a promising route to achieving uniformity and improved corrosion resistance in Al matrix composites, while pointing to the need for further research to fully elucidate the operative mechanisms.</p>","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141893612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emmanuel Soubies, Alejandro Nogueron, Florence Pelletier, Thomas Mangeat, Christophe Leterrier, Michael Unser, Daniel Sage
{"title":"Surpassing light inhomogeneities in structured-illumination microscopy with FlexSIM","authors":"Emmanuel Soubies, Alejandro Nogueron, Florence Pelletier, Thomas Mangeat, Christophe Leterrier, Michael Unser, Daniel Sage","doi":"10.1111/jmi.13344","DOIUrl":"10.1111/jmi.13344","url":null,"abstract":"<p>Super-resolution structured-illumination microscopy (SIM) is a powerful technique that allows one to surpass the diffraction limit by up to a factor two. Yet, its practical use is hampered by its sensitivity to imaging conditions which makes it prone to reconstruction artefacts. In this work, we present FlexSIM, a <i>flexible</i> SIM reconstruction method capable to handle highly challenging data. Specifically, we demonstrate the ability of FlexSIM to deal with the distortion of patterns, the high level of noise encountered in live imaging, as well as out-of-focus fluorescence. Moreover, we show that FlexSIM achieves state-of-the-art performance over a variety of open SIM datasets.</p>","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jmi.13344","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141620144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deep learning for quantifying spatial patterning and formation process of early differentiated human-induced pluripotent stem cells with micropattern images","authors":"Slo-Li Chu, Kuniya Abe, Hideo Yokota, Dooseon Cho, Yohei Hayashi, Ming-Dar Tsai","doi":"10.1111/jmi.13346","DOIUrl":"10.1111/jmi.13346","url":null,"abstract":"<p>Micropatterning is reliable method for quantifying pluripotency of human-induced pluripotent stem cells (hiPSCs) that differentiate to form a spatial pattern of sorted, ordered and nonoverlapped three germ layers on the micropattern. In this study, we propose a deep learning method to quantify spatial patterning of the germ layers in the early differentiation stage of hiPSCs using micropattern images. We propose decoding and encoding U-net structures learning labelled Hoechst (DNA-stained) hiPSC regions with corresponding Hoechst and bright-field micropattern images to segment hiPSCs on Hoechst or bright-field images. We also propose a U-net structure to extract extraembryonic regions on a micropattern, and an algorithm to compares intensities of the fluorescence images staining respective germ-layer cells and extract their regions. The proposed method thus can quantify the pluripotency of a hiPSC line with spatial patterning including cell numbers, areas and distributions of germ-layer and extraembryonic cells on a micropattern, and reveal the formation process of hiPSCs and germ layers in the early differentiation stage by segmenting live-cell bright-field images. In our assay, the cell-number accuracy achieved 86% and 85%, and the cell region accuracy 89% and 81% for segmenting Hoechst and bright-field micropattern images, respectively. Applications to micropattern images of multiple hiPSC lines, micropattern sizes, groups of markers, living and fixed cells show the proposed method can be expected to be a useful protocol and tool to quantify pluripotency of a new hiPSC line before providing it to the scientific community.</p>","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jmi.13346","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141590537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}