VitriFlex: An Open-Source, Modular, and Customizable Robotic Platform for Cryo-EM Grid Preparation.

Cryo-EM structure and functional analyses show that human iron exporter ferroportin (Fpn) can bind and transport calcium ions and the transport activity is reduced when the concentration of ferrous ions is high.

The cryo-EM structure of ETB-Gi complex, obtained using the Fusion-G system, provides insights into the distinct activation mechanism and G-protein promiscuity of ETB, aiding in the design of ETB agonists for therapeutic applications.

Single-step antibody-based affinity cryo-electron microscopy for imaging and structural analysis of macromolecular assemblies.

A simple and robust procedure for preparing graphene-oxide cryo-EM grids.

Recent technological breakthroughs in single-particle cryo-electron microscopy (cryo-EM) enable rapid atomic structure determination of biological macromolecules. A major bottleneck in the current single particle cryo-EM pipeline is the preparation of good quality frozen cryo-EM grids, which is mostly a trial-and-error process. Among many issues, preferred particle orientation and sample damage by air–water interface (AWI) are common practical problems. Here we report a method of applying metallo-supramolecular branched polymer (MSBP) in the cryo-sample preparation for high-resolution single-particle cryo-EM. Our data shows that MSBP keeps a majority of particles away from air–water interface and mitigates preferred orientation as verified by the analyses of apoferritin, hemagglutinin) trimer and various sample proteins. The use of MSBP is a simple method to improve particle distribution for high-resolution structure determination in single-particle cryo-EM.

The use of simple and economic traps with long lasting lure dispensers is key for implementation of mass trapping strategies against pestiferous fruit flies. Simplicity, cost, ease of assembly, storage and transportation were considered during evaluation of a folding conical trap for mass trapping the Mexican fruit fly, Anastrepha ludens. The application of deltamethrin to the lid of the trap resulted in a cost-effective treatment, which helped retain flies in dry traps for at least 10 wk. However, the conical trap design and the diam, type and disposition of entry-holes, negatively affected performance of the trap under laboratory conditions. High numbers of flies could escape the trap over a short period of time after their release into its interior, although most of them died after escaping because of the delayed effect of exposure to deltamethrin. Under field conditions, no significant differences were observed between orange and yellow traps in capturing either A. ludens or lacewings. In contrast, the folding conical trap model was significantly more efficient in capturing Mexican fruit flies when baited with CeraTrap® lure than when baited either with the conventional hydrolyzed protein or with BioLure®. CeraTrap® lure was also significantly more attractive to beneficial lacewings than the other 2 lures. These results indicated that additional studies on fly population suppression under field conditions will be necessary before deciding to use the folding conical trap as part of a mass trapping strategy to control the Mexican fruit fly.

Standardized and accessible multi-omics bioinformatics workflows through the NMDC EDGE resource

In this work, a modular and open-source platform has been developed for integrating hybrid battery energy storage systems that are intended for grid applications. Alongside integration, this platform will facilitate testing and optimal operation of hybrid storage technologies. Here, a hardware testbed and a control software have been designed, where the former comprises commercial Lithium-iron-phosphate <tex>$(LiFePO_{4})$</tex> and Lead Acid (Pb - acid) cells, custom built Dual Active Bridge (DAB) DC-DC converters, and a commercial DC-AC conversion system. In this testbed the batteries have an operating voltage range of ~11-15V, the DC-AC conversion stage has a DC link voltage of 24V, and it connects to a <tex>$\boldsymbol{208}\mathbf{V}3-\phi$</tex> grid. The hardware testbed can be scaled up to higher voltages. The control software is developed in Python, and the firmware for all the hardware components is developed in C. This software implements hybrid charge/discharge protocols that are suitable for each battery technology for preventing cell degradation, and perform uninter-rupted quality checks on selected battery packs. The developed platform provides flexibility, modularity, safety and economic benefits to utility-scale storage integration.

The radio frequency (RF) laboratory hosted in the Corpuscular Physics Institute (IFIC) of the University of Valencia is designed to house a high-power and high-repetition-rate facility to test normal conduction RF accelerator cavities in the S-Band (2.9985 GHz) in order to perform R&amp;D activities related to particle accelerator cavities. The system, which manages the entire process of RF signal generation, data acquisition and closed-loop control of the laboratory, is currently based on a modular and compact PXI platform system. This contribution details the development of a platform with similar features, but which is based on open architecture standards at both the hardware and software level. For this purpose, a complete system based on the μTCA platform has been developed. This new system must be able to work with accelerator cavities at other operating frequencies, such as 750 MHz, as well as to explore different options at firmware and software levels based on open-source codes.

Adaptive multi-epitope targeting and avidity-enhanced nanobody platform for ultrapotent, durable antiviral therapy

Enzyme nanoreactors are nanoscale compartments consisting of encapsulated enzymes and a selectively permeable barrier. Sequestration and co-localization of enzymes can increase catalytic activity, stability, and longevity, highly desirable features for many biotechnological and biomedical applications of enzyme catalysts. One promising strategy to construct enzyme nanoreactors is to repurpose protein nanocages found in nature. However, protein-based enzyme nanoreactors often exhibit decreased catalytic activity, partially caused by a mismatch of protein shell selectivity and the substrate requirements of encapsulated enzymes. No broadly applicable and modular protein-based nanoreactor platform is currently available. Here, we introduce a pore-engineered universal enzyme nanoreactor platform based on encapsulins – microbial self-assembling protein nanocompartments with programmable and selective enzyme packaging capabilities. We structurally characterize our protein shell designs via cryo-electron microscopy and highlight their polymorphic nature. Through fluorescence polarization assays, we show their improved molecular flux behavior and highlight their expanded substrate range via a number of proof-of-concept enzyme nanoreactor designs. This work lays the foundation for utilizing our encapsulin-based nanoreactor platform for future biotechnological and biomedical applications.

Affordable 3D-printed prototype integrated with open-source electronic platform for low-cost polyamide noncoated adsorption-based microextraction.

Air-water interface (AWI) interactions during cryo-electron microscopy (cryo-EM) sample preparation cause significant sample loss, hindering structural biology research. Organisms like nematodes and tardigrades produce Late Embryogenesis Abundant (LEA) proteins to withstand desiccation stress. Here we show that these LEA proteins, when used as additives during plunge freezing, effectively mitigate AWI damage to fragile multi-subunit molecular samples. The resulting high-resolution cryo-EM maps are comparable to or better than those obtained using existing AWI damage mitigation methods. Cryogenic electron tomography reveals that particles are localized at specific interfaces, suggesting LEA proteins form a barrier at the AWI. This interaction may explain the observed sample-dependent preferred orientation of particles. LEA proteins offer a simple, cost-effective, and adaptable approach for cryo-EM structural biologists to overcome AWI-related sample damage, potentially revitalizing challenging projects and advancing the field of structural biology.

Electron cryomicroscopy (cryo-EM) has revolutionised structural biology, enhancing applicability, size limits and speed. Despite these successes, cryo-EM sample preparation remains a major bottleneck for routinely achieving high-resolution structures through single particle analysis. Challenges such as inconsistent ice thicknesses, air-water interface interactions and preferred particle orientation persist. Here, we introduce a blot-free vitrification method that uses free-standing surfactant-stabilised foam films to address some of these issues. The method achieves uniform ice thicknesses, enables thickness control of the foam film prior to vitrification, and for some specimens enhances orientation distribution efficiency. Furthermore, it reduces particle adsorption to carbon foil on the specimen support. The method simplifies cryo-EM specimen preparation, offering improved control over ice thickness and particle orientation, to help streamline and accelerate structure determination.

Efficient, reproducible and accountable single-particle cryo-electron microscopy structure determination is tedious and often impeded by the lack of a standardized procedure for data analysis and processing. To address this issue, we have developed the FMI Live Analysis and Reconstruction Engine (CryoFLARE). CryoFLARE is a modular open-source platform offering easy integration of new processing algorithms developed by the cryo-EM community. It provides a user-friendly interface that allows fast setup of standardized workflows, serving the need of pharmaceutical industry and academia alike who need to optimize throughput of their microscope. To consistently document how data is processed, CryoFLARE contains an integrated reporting facility to create reports. Live analysis and processing parallel to data acquisition are used to monitor and optimize data quality. Problems at the level of the sample preparation (heterogeneity, ice thickness, sparse particles, areas selected for acquisition, etc.) or misalignments of the microscope optics can quickly be detected and rectified before data collection is continued. Interfacing with automated data collection software for retrieval of acquisition metadata reduces user input needed for analysis, and with it minimizes potential sources of errors and workflow inconsistencies. Local and remote export support in Relion-compatible job and data format allows seamless integration into the refinement process. The support for nonlinear workflows and fine-grained scheduling for mixed workflows with separate CPU and GPU based calculation steps ensures optimal use of processing hardware. CryoFLARE's flexibility allows it to be used for all types of image acquisitions, ranging from sample screening to high-resolution data collection, and it offers a new alternative for setting up image processing workflows. It can be used without modifications of the hardware/software delivered by the microscope supplier. As it runs on a server in parallel to the hardware used for acquisition, it can easily be set up for remote display connections and fast control of the acquisition status.