Journal of microscopy最新文献

Tissue slices can undergo distortions during processing into resin for light and electron microscopy as a result of differential shrinkage of the various tissue components, and this may necessitate removal of a considerable amount of material from the final resin-embedded tissue block to ensure production of complete sections of the sample. To mitigate this problem, a number of techniques have been devised that ensure the sample is held flat during the final curing/polymerisation of the resin. For embedding in acrylic resins, oxygen must be excluded as it inhibits polymerisation, and methods devised for epoxy resin embedding are generally unsuitable. The method describes the preparation and use of air-tight flat-embedding chambers prepared from Melinex film and provides an inexpensive, technically simpler, and versatile alternative to chambers formed from either Thermanox coverslips or Aclar films that have previously been advocated for such purposes. Lay description: Tissue slices can undergo distortions during processing into resin for light and electron microscopy as a result of differential shrinkage of the various tissue components. Such distortions may necessitate removal of a considerable amount of material to ensure production of complete sections of the sample. For embedding in acrylic resins, oxygen must be excluded as it inhibits polymerisation, and methods devised for epoxy resin flat-embedding are generally unsuitable. Air-tight flat-embedding chambers prepared from either Thermanox coverslips, or a combination of PTFE-coated glass slides, polycarbonate film gaskets, and Aclar film have been advocated for such purposes. Thermanox coverslips are expensive and limited in size to 22 mm × 60 mm, and the alternative method is technically complicated. Melinex film is commercially available as 210 mm × 297 mm sheets and is approximately 1/20th the price of Thermanox and less than half the price of Aclar film. The method describes the preparation and use of embedding chambers made from Melinex film, glass slides and double-sided adhesive tape as a technically simpler, inexpensive and versatile alternative to both Thermanox coverslips and the Aclar film method.

The endoplasmic reticulum (ER) is the largest organelle in terms of membrane content, occupying the entire cytoplasmic volume. It is tethered to the cell cortex through ER-plasma membrane contact sites (EPCS). Previous studies have shown that EPCSs labelled by VAP27 align with cortical microtubules, and that ER tubules elongate along microtubules. Here, we addressed the question whether this relationship is bidirectional, with EPCSs influencing microtubule organisation. Using TIRF microscopy to track EPCSs and microtubule dynamics simultaneously, we demonstrate that while EPCSs remain stable, microtubules are highly dynamic and can adjust their positioning based on nearby EPCS in Arabidopsis cotyledon epidermis. In lobes of epidermal cells enclosed by two indentations, where microtubules bundle together, EPCSs flank the bundles and exhibit a distinctive arrangement, forming symmetric arcs in relation to the lobe axis. In guard cells, transversely oriented ER tubules co-align with microtubules. Disrupting microtubules with the drug oryzalin leads to transient guard cells-ER remodelling, followed by its reorganisation into transverse tubules before microtubule recovery. Taken together our observations suggest, that the positioning of EPCSs and cortical microtubules, can affect each other and the organisation of cortical ER.

Roldan, D., Redenbach, C., Schladitz, K., Kübel, C., & Schlabach, S. (2024). Image quality evaluation for FIB-SEM images. Journal of Microscopy, 293(2), 98-117. https://onlinelibrary.wiley.com/doi/10.1111/jmi.13254

Diego Roldan's affiliation appears as “National University, Bogotá, Colombia”

The correct affiliation is “Departamento de Matemáticas, Universidad Nacional de Colombia, Bogotá, Colombia”

We apologise for this error.

Interferometric scattering (iSCAT) microscopy enables high-speed and label-free detection of individual molecules and small nanoparticles. Here we apply point spread function engineering to provide adaptive control of iSCAT images using spatial light modulation. With this approach, we demonstrate improved dynamic spatial filtering, real-time background subtraction, focus control, and signal modulation based on sample orientation.

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.

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

Chvalova, V., Vomastek, T., & Grousl, T. (2024). Comparison of holotomographic microscopy and coherence-controlled holographic microscopy. Journal of Microscopy, 294(1), 5–13. https://onlinelibrary.wiley.com/doi/10.1111/jmi.13260

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)”.

We apologise for this error.

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.