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Recent advances in instrumentation and automation have made cryo-EM a popular method for producing near-atomic resolution structures of a variety of proteins and complexes. Sample preparation is still a limiting factor in collecting high quality data. Thickness of the vitreous ice in which the particles are embedded is one of the many variables that need to be optimized for collection of the highest quality data. Here we present two methods, using either an energy filter or scattering outside the objective aperture, to measure ice thickness for potentially every image collected. Unlike geometrical or tomographic methods, these can be implemented directly in the single particle collection workflow without interrupting or significantly slowing down data collection. We describe the methods as implemented into the Leginon/Appion data collection workflow, along with some examples from test cases. Routine monitoring of ice thickness should prove helpful for optimizing sample preparation, data collection, and data processing.
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http://dx.doi.org/10.1016/j.jsb.2018.06.007 | DOI Listing |
J Cardiovasc Electrophysiol
September 2025
Department of Cardiology, Second Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, China.
Background And Aims: Ablation for premature ventricular complexes (PVCs) originating from the right ventricular inflow tract (RVIT) is challenging. Few studies have identified the correlation between right ventricular false tendons (RVFTs) and RVIT PVCs. This study aimed to verify RVFTs as arrhythmogenic and electro-anatomical substrates for PVCs, and propose an enlightening mapping and ablation protocol to improve operative efficacy.
View Article and Find Full Text PDFCryobiology
September 2025
UCIBIO - Applied Molecular Biosciences Unit, Department of Chemistry, School of Science and Technology, NOVA University Lisbon, Caparica, Portugal; Associate Laboratory i4HB - Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, Caparica, Portugal. Electroni
High-throughput experimental screening is desirable to minimize data acquisition time from vast workloads. Cell cryopreservation experiments are routinely performed in single-sample cryovials despite cell seeding being performed in 96-well microplates because these substrates are known to induce microliter supercooling, are prone to thermal compressibility and their lengthy preparation period extends cell exposure time to potentially cytotoxic cryoprotectants. Rather than improving the methodological preciseness of cooling, latest efforts have focused on refining cryoprotectant formulations and supplement precautionary ice nucleators.
View Article and Find Full Text PDFISME J
August 2025
School of Oceanography & Astrobiology Program, University of Washington, Seattle, WA, USA.
Despite growing evidence for the role of DNA methylation in bacterial acclimation to environmental stress, this epigenetic mechanism remains unexplored in sea-ice microbial communities known to tolerate multiple stressors. This study presents a first analysis of DNA methylation patterns in bacterial communities and associated viruses across the vertical thickness of sea ice. Using a novel stepped-sackhole method, we collected sea-ice brines from distinct horizons of an Arctic ice floe, capturing microbial communities that had been exposed to different environmental conditions.
View Article and Find Full Text PDFMedicina (Kaunas)
July 2025
Hospital Virgen de la Concha, 49022 Zamora, Spain.
: Although the use of allografts in revision anterior cruciate ligament reconstruction is associated with theoretical advantages, it has historically led to poorer clinical results and lower survival rates. However, the heterogeneity of the available literature makes it difficult to elucidate the effectiveness of allographs, as most of the studies published do not make any reference to some of the key aspects related to the processing of the allograft employed. The present study analyzed the clinical results and the survival of allografts in patients undergoing revision anterior cruciate ligament reconstruction with a well-characterized, single type of allograft.
View Article and Find Full Text PDFJ Microsc
August 2025
Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
The contributions of coherent bright-field phase and incoherent dark-field amplitude contrast are investigated for thick biological specimens. A model for a T4 phage is constructed and images simulated for both TEM and STEM phase contrast using a multislice code. For TEM, the fraction of the illumination intensity available for phase contrast imaging is limited by the fraction of electrons in the zero loss peak, the plasmon peak, or the Landau distribution peak for very thick specimens.
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