Deep neural networks in real-time coherent diffraction imaging

The potential for convolutional neural networks to provide real-time imaging capabilities for coherent diffraction imaging experiments at XFELs is discussed.

Distortions, deviations and alternative facts: reliability in crystallography

In this text based on the 2018 Lonsdale lecture, beginning with early work by Kathleen Lonsdale, instructive examples are given of unusual and unexpected structures derived from X-ray crystallography, not all of which are genuine results.

Complex imaging of phase domains by deep neural networks

Machine-learning approaches can greatly facilitate single-particle-imaging experiments at X-ray free-electron-laser facilities by providing real-time images from the coherent X-ray diffraction data stream, using methods presented in this article.

Direct localization of detergents and bacteriorhodopsin in the lipidic cubic phase by small-angle neutron scattering

Using small-angle neutron scattering with contrast-matching of the lipidic cubic phase (LCP) bilayer, we determined that bacteriorhodopsin (bR) and detergents are largely dissociated upon incorporation into the LCP. This implies that the crystallization of membrane proteins in LCP is relatively insensitive to the choice of detergent, unlike the solution case, and this was experimentally verified with several detergents for bR.

Local and long-range atomic/magnetic structure of non-stoichiometric spinel iron oxide nanocrystallites

The atomic, magnetic and nano-structure of hydro­thermally synthesized non-stoichiometric spinel iron oxide nanoparticles are examined in detail using a wide range of advanced structural characterization methods. The present study constitutes the first use of the recently developed magnetic pair-distribution-function analysis method to model the local magnetic structure in nanoparticles.

Joint neutron/X-ray crystal structure of a mechanistically relevant complex of perdeuterated urate oxidase and simulations provide insight into the hydration step of catalysis

The joint neutron/X-ray crystallographic structure of perdeuterated Aspergillus flavus urate oxidase in complex with the inhibitor 8-azaxanthine and a catalytic water bound in the peroxo hole is presented together with an integrated analysis using biomolecular simulations.

Exploiting prior knowledge about biological macromolecules in cryo-EM structure determination

The incorporation of prior knowledge about the structures of biological macromolecules into the reconstruction process of cryo-EM structure determination is proposed. Using a novel algorithm inspired by regularization by denoising, it is shown how convolutional neural networks can be used within this framework to improve reconstructions from simulated data.

Crystal structure determination of a lifelong biopersistent asbestos fibre using single-crystal synchrotron X-ray micro-diffraction

The in vivo lifelong stability of an amphibole asbestos fibre extracted from a lung of a patient affected by malignant mesothelioma has been verified using synchrotron X-ray micro-diffraction.

Insight into the structure of decagonite – the extraterrestrial decagonal quasicrystal

The crystal structure of decagonite, Al₇₁Ni₂₄Fe₅, the only known natural decagonal quasicrystal found in a meteorite formed at the beginning of the Solar System is reported. The structural model obtained shows peculiarities and slight differences with respect to those obtained for other synthetic decagonal quasicrystals.

General method to calculate the elastic deformation and X-ray diffraction properties of bent crystal wafers

A general method to calculate the elastic deformation and X-ray diffraction curves of arbitrarily shaped, toroidally bent crystal wafers based on the free-energy minimization is presented.

Hydrogen disorder in kaatialaite Fe[AsO₂(OH)₂]5H₂O from Jáchymov, Czech Republic: determination from low-temperature 3D electron diffraction

The hydrogen disorder in kaatialaite mineral Fe[AsO₂(OH)₂]5H₂O from Jáchymov, Czech Republic, is reported. A new analysis using 3D electron diffraction at low temperature demonstrates that even partial hydrogen positions are accessible among heavy atoms from the refinement of 3D electron-diffraction data, even when ignoring the dynamical effects.

Nanosecond X-ray photon correlation spectroscopy using pulse time structure of a storage-ring source

Nanosecond XPCS study of fast colloidal dynamics is demonstrated by employing the intrinsic pulse structure of the storage ring with AGIPD. Correlation functions from single-pulse speckle patterns with the shortest correlation time of 192 ns have been measured, providing an important step towards routine ultrafast XPCS studies at storage rings.

Crystal structure of death-associated protein kinase 1 in complex with the dietary compound resveratrol

The dietary compound resveratrol is an inhibitor of death-associated protein kinase 1.

Single-crystal-to-single-crystal phase transitions of commensurately modulated sodium saccharinate 1.875-hydrate

Two phase transitions of commensurately modulated Na(sac)(15/8)H₂O have been discovered upon cooling. All three phases involve complex disorder. The crystal exhibits an unusual reentrant disorder upon cooling through the first phase transition at 130 K.