IUCrJ in 2025 – welcomes, farewells and special issues

As we start a new year, it is timely to welcome two new Main Editors of IUCrJ and bid farewell to those who have stepped down, as well as highlight a couple of ongoing developments of interest to IUCrJ readers and authors.

Radiation damage and the case for unpatterned fixed targets

Advances in serial crystallography have reshaped approaches to radiation damage at room temperature. This commentary highlights recent work comparing XFEL and synchrotron experiments, emphasizing its implications for serial crystallography at modern X-ray sources.

AutoLEI: A step towards automatic 3D ED data processing

A user-friendly interface has been developed for XDS, enabling efficient real-time and batch processing of 3D ED data to accelerate structure determination.

Exploring fibers with X-ray eyes

The novel analytical approach for interpreting complex X-ray diffraction patterns from fibers described by Wang et al. [(2026), IUCrJ, 13, 63–76] is discussed.

Broadband high-resolution X-ray ptychography system spanning tender to hard X-ray regimes

An advanced X-ray ptychography system has been developed that facilitates nanoscale imaging across both tender and hard X-ray regions using a single optical setup.

Structural insights into the antiviral efficacy of AG7404 against human rhinovirus 3C proteases

This study presents the crystal structure of human rhinovirus (hRV)-B14 3C protease bound to AG7404, a broad-spectrum antiviral inhibitor, at a resolution of 2.11 Å. Antiviral assays and in silico studies provide structural insights into AG7404's efficacy and binding mechanism against hRV-B14, hRV-A16 and hRV-A21 3C proteases.

Structure of the bacteriophage PhiKZ non-virion RNA polymerase bound to a p119L open promoter analogue

Bacteriophage ΦKZ is a massive bacterial virus with potential as a therapy for Pseudomonas aeruginosa, which forms a bacteriophage nucleus in infected cells to exclude the host immune system, and transcribes its genes with its own, non-canonical multi-subunit RNA polymerase. The structure of this polymerase in the process of binding an analogue of its cognate promoter is resolved, revealing an unanticipated method of promoter consensus recognition involving the β-like, rather than the σ-factor-like subunit.

Obtaining single crystals containing cationic porphyrins from aqueous solutions: a systematic approach including nano-crystallization, organic modifiers and gel crystallization

A stepwise guide to the crystallization of charged molecules from aqueous solutions is presented.

Linear-scaling aspherical crystallographic refinement of proteins: a case study for crambin and rubredoxin

Linear-scaling fragment Hirshfeld atom refinement has been implemented in Olex2 within the NoSpherA2 interface, which also solved previous issues with hydrogen bonds. This allowed the refinement of two small proteins, crambin and rubredoxin (the latter including a metal site), with quantum mechanical aspherical atomic form factors.

Anisotropic diffraction of materials with fibre symmetry: application to chitin cuticle

A generalized diffraction model is presented for anisotropic nanomaterials with fibre symmetry, enabling the extraction of 3D orientation, strain and angular dispersion from wide-angle X-ray scattering patterns without sample rotation. Validated on chitinous Bouligand structures in shrimp cuticle, this framework allows robust multi-reflection analysis and is broadly applicable to complex biological and synthetic fibre-based materials.

The relationship between the Ewald sphere and exit wave explored using focal series electron micrographs

The Ewald sphere is inherent in image formation in the electron microscope and must therefore be part of the reconstruction of cryoEM maps. This study examines linear image-formation theory to show how Ewald sphere information derives from focal series micrographs and relates to the exit wave. It concludes by suggesting the proper way to correct for the contrast transfer function for cryoEM reconstruction.

Crystal structure of di­acet­ylene unveiled by X-ray and neutron diffraction, Raman spectroscopy and periodic DFT

The crystal structure and thermal expansion behaviour of di­acet­y­lene were determined via diffraction methods and supplemented by spectroscopic techniques. The similarities to the structure of acetylene and implications for Titan in situ exploration are discussed.

AutoLEI: An XDS-based pipeline with graphical user interface for automated real-time and offline batch 3D ED/microED data processing

A pipeline with a graphical user interface for real-time and offline 3D ED/microED data processing by XDS was developed. The pipeline aims to improve efficiency, minimize redundant data processing work and provide users with real-time feedback during data collection.

Phase transitions in rutile-related V_0.92O₂ synthesized at high pressures and tem­per­atures

Phase transitions in metastable rutile-related V_0.92O₂ were studied with single-crystal X-ray diffraction and measurements of electronic transport properties at extreme conditions. The high-tem­per­a­ture incommensurate phase was found to be insulating.