Since the outbreak of the SARS-CoV-2 pandemic, there have been intense structural studies on purified viral components and inactivated viruses. However, structural and ultrastructural evidence on how the SARS-CoV-2 infection progresses in the native cellular context is scarce, and there is a lack of comprehensive knowledge on the SARS-CoV-2 replicative cycle. To correlate cytopathic events induced by SARS-CoV-2 with virus replication processes in frozen-hydrated cells, we established a unique multi-modal, multi-scale cryo-correlative platform to image SARS-CoV-2 infection in Vero cells. This platform combines serial cryoFIB/SEM volume imaging and soft X-ray cryo-tomography with cell lamellae-based cryo-electron tomography (cryoET) and subtomogram averaging. Here we report critical SARS-CoV-2 structural events – e.g. viral RNA transport portals, virus assembly intermediates, virus egress pathway, and native virus spike structures, in the context of whole-cell volumes revealing drastic cytppathic changes. This integrated approach allows a holistic view of SARS-CoV-2 infection, from the whole cell to individual molecules.

This protocol describes sample preparation strategies for correlative 3D cryo-SIM and cryo soft X-ray tomography. In addition, the authors provide a direct comparison and recommendations regarding the selection and use of fiducials for 3D correlation. TWEET A new protocol for sample preparation and fiducial selection for correlative cryo-SIM and cryo-soft X-ray tomography. #CLXT #cryoimaging #cellstructure #correlativeimaging COVER TEASER Correlative cryo-SIM and cryo-soft X-ray tomographyAbstract 3D correlative microscopy methods have revolutionised biomedical research allowing the acquisition of multi-dimensional information to gain an in-depth understanding of biological systems. With the advent of relevant cryo-preservation methods, correlative imaging of cryogenically preserved samples has led to nanometre resolution imaging (2-50 nm) under harsh imaging regimes such as electron and soft X-ray tomography. These methods have now been combined with conventional and super resolution fluorescence imaging at cryogenic temperatures to augment information content from a given sample resulting in the immediate requirement for protocols that facilitate hassle-free unambiguous cross correlation between microscopes. We present here sample preparation strategies and a direct comparison of different working fiducialisation regimes that facilitate 3D correlation of cryo-structured illumination microscopy and cryo-soft X-ray tomography. Our protocol has been tested at two synchrotron beamlines (B24 at Diamond Light Source in the UK and BL09 Mistral at ALBA in Spain) and has led to the development of a decision aid that facilitates experimental design with the strategic use of markers based on project requirements. This protocol takes between 1.5 hours and 3.5 days to complete, depending on the cell populations used (adherent cells may require several days to grow on sample carriers).

Lithium ion battery (LIB) technology is the state-of-the-art rechargeable energy storage technology for electric vehicles, stationary energy storage and personal electronics. However, a wide variety of degradation effects still contribute to performance limitations. The metallic copper and aluminium current collectors in an LIB can be subject to dissolution or other reactions with the electrolytes. Corrosion of these metal foils is significantly detrimental to the overall performance of an LIB, however the mechanisms of this degradation are poorly understood. This review summarises the key effects contributing to metal current collector degradation in LIBs as well as introduces relevant corrosion and LIB principles. By developing the understanding of these complex chemistries, LIB degradation can be mitigated, enabling safer operation and longer lifetimes.

Despite their ubiquitous usage and increasing societal dependence on Li-ion batteries, there remains a lack of detailed empirical evidence of Li intercalation/deintercalation into graphite even though this process dictates the performance, longevity, and safety of the system. Here, we report direct detection and dissociation of specific crystallographic phases in the lithiated graphite, which form through a stepwise staging process. Using operando measurements, LiC18, LiC12, and LiC6 phases are observed via distinct low-frequency Raman features, which are the result of displacement of the graphite lattice by induced local strain. Density functional theory calculations confirm the nature of the Raman-active vibrational modes, to the layer breathing modes (LBMs) of the lithiated graphite. The new findings indicate graphene-like characteristics in the lithiated graphite under the deep charged condition due to the imposed strain by the inserted Li. Moreover, our approach also provides a simple experimental tool to measure induced strain in the graphite structure under full intercalation conditions.