After their crystallization from magmatic melt, minerals such as accessory zircon are often subject to different kinds of chemical impairment. This includes the radiation-induced damage of the crystal lattice due to the incorporation of radioactive elements (U, Th) and the dissolution of the mineral structure due to the permanent action of aggressive fluid phases. Both phenomena can be best studied by using specific crystal sections and electron microscopy visualization techniques (backscattered electron imaging, BSEI). Crystal damage by the emission of α-particles corresponds to a continuous transformation of the regularly structured lattice into an amorphous mass. Mineral dissolution is expressed by the formation of specific corrosion pits, which may be refilled by recrystallized material.

Certain bacteria degrade wood by creating tunnels in cell walls. Transmission electron microscopy (TEM) has played a key role in understanding the intricate architecture of the tunnels produced within the cell wall and the process of cell wall degradation. The most prominent feature of tunnels is the presence of periodic crescent-shaped slime bands, which is the single most important diagnostic characteristic of bacterial tunneling-type cell wall degradation. The review presented covers the aspects relevant to understanding bacterial tunneling of wood cell walls, emphasizing the importance of the application of TEM in this area of research.

Scanning electron microscopes (SEMs) are a popular analytical tool due to their high spatial resolution, large depth of field, and analytical capabilities. However, in many cases, the large-scale installation and cost of SEMs can be a barrier to entry for smaller laboratories or facilities. The introduction of a more compact benchtop SEM has changed the landscape, enabling scientists in many fields to adopt the technology and revolutionize research. Benchtop SEMs can be used in a variety of industries including materials science, pharmaceutical research, energy exploration, science education, and academia. These industries require analysis at the nanoscale for quality control, failure analysis, and R&D, for all of which the benchtop SEM is perfectly positioned to provide necessary detail. These advantages and new developments in the technology have made the benchtop SEM a widely available and well-accepted tool.

This article is the second within a three-part series on Fourier ptychography, which is a computational microscopy technique for high-resolution, large field-of-view imaging. While the first article laid out the basics of Fourier ptychography, this second part sheds light on its algorithmic ingredients. We present a non-technical discussion of phase retrieval, which allows for the synthesis of high-resolution images from a sequence of low-resolution raw data. Fourier ptychographic phase retrieval can be carried out on standard, widefield microscopy platforms with the simple addition of a low-cost LED array, thus offering a convenient alternative to other phase-sensitive techniques that require more elaborate hardware such as differential interference contrast and digital holography.

This article introduces a training simulator for electron beam alignment using Ronchigrams. The interactive web application, www.ronchigram.com, is an advanced educational tool aimed at making scanning transmission electron microscopy (STEM) more accessible and open. For experienced microscopists, the tool offers on-hand quantification of simulated Ronchigrams and their resolution limits.