B23-Circular Dichroism
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Leo
Delage-Laurin
,
David
Reger
,
Abdusalom A.
Suleymanov
,
Zachary
Nelson
,
Louis
Minion
,
Steven
Kooi
,
Jochen R.
Brandt
,
Giuliano
Siligardi
,
Robert P.
Cameron
,
Jessica
Wade
,
Timothy M.
Swager
,
Matthew J.
Fuchter
Diamond Proposal Number(s):
[29153, 31975, 33533]
Open Access
Abstract: Connections between magnetic field induced optical activity and chirality have a rich and complicated history. Although the broken inversion symmetry of chiral molecules generates ‘natural’ optical activity, magnetic optical activity is generated by breaking time reversal symmetry. Therefore, molecular chirality is not expected to influence magnetic optical phenomena, such as Faraday rotation. Here we show that the chiral supramolecular assembly of polymers can result in large Faraday effects (Verdet constants = 105 °T–1m–1). This strong Faraday rotation, which is amongst the highest value known for organic materials, originates from the so-called Faraday B term. Typically, B term Faraday responses are weak. We demonstrate large amplification through excitonic coupling within the supramolecular assembly, where the chirality of the system controls the assembly formed. These observations provide an alternative means to enhance the Faraday rotation of low symmetry systems and clarify the role of chirality in previous reported materials.
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Nov 2025
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I04-Macromolecular Crystallography
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Diamond Proposal Number(s):
[25413]
Open Access
Abstract: In directed evolution, enzyme activity is improved in successive generations of laboratory evolution, which can be described by a simple stepwise climb toward a peak in the fitness landscape. In a naive model of evolution, it can be assumed that each enzyme variant along this path is in a single, well-defined state that differs slightly from the previous one. We analyzed the structural changes in mutants of the β-lactamase BlaC from Mycobacterium tuberculosis obtained via directed evolution for increased ceftazidime hydrolysis activity. Crystal structures of three successive mutants only show an increase in the dynamics of a loop that lines the active site (Ω-loop), enabling better access of the large substrate. However, NMR spectra of wild type and nine mutants of different branches of the directed evolution experiment show a much more diverse and complex picture of the conformational effects. Many mutants show micro-millisecond dynamics for certain regions and most show peak doubling, indicative of two or more conformations being populated. Thus, the straightforward climb to increased ceftazidime activity in the fitness landscape masks a complex trajectory in the conformational landscape, emphasizing the complex and epistatic interplay that single mutations can have on the structure and dynamics of enzymes.
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Nov 2025
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B21-High Throughput SAXS
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Diamond Proposal Number(s):
[31378]
Open Access
Abstract: Amphiphilic compounds, such as phospholipids or surface-active substances, are present in biological systems and can be part of pharmaceutical formulations. As a consequence, all pharmaceutically active ingredients will encounter amphiphilic compounds, either in the formulation or after administration. With the growing interest in peptide-based pharmaceuticals, there is a need to enhance the understanding of the interactions between peptides and amphiphilic compounds.
In this particular study, we have chosen to study mixtures of the comparatively small cyclical octapeptide lanreotide and the conventional anionic surfactant sodium dodecylsulfate (SDS). This was done by examining the self-assembly structures formed in lanreotide-SDS mixtures using light scattering and small-angle X-ray scattering (SAXS).
Above the critical micelle concentration (cmc) of SDS, the large excess of SDS could solubilize all lanreotide and form small micelles with lanreotide attached to the interface. Upon dilution to concentrations below the cmc of SDS, a suspension with dispersed solid nanoparticles is formed. The solid nanoparticles grow in size with decreasing concentration and, eventually, precipitate. The precipitated material is arranged in a liquid crystalline micellar phase, consisting of small close-packed SDS micelles with peptide adsorbed at the interface.
We were able to conclude that lanreotide does not form mixed micelles with SDS, indicating that it lacks the amphiphilic properties required to integrate fully with SDS behaving as a cosurfactant. In contrast, lanreotide attaches to the interface of SDS micelles, resembling the interactions of polymers, proteins, and nucleic acids with surfactants.
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Nov 2025
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I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[29113]
Open Access
Abstract: LiNi0.5Mn1.5O4 (LNMO) cathodes offer a cobalt-free, high-voltage alternative to current state-of-the-art Li-ion battery cathodes, and are particularly well-suited for high-power applications due to their 3D lithium-ion pathways and structural stability. However, degradation of commercial electrolytes at high voltages exacerbates capacity decay, as instability at the cathode surface causes active material loss, surface reconstructions, thickening surface layers, and increases in internal cell resistance. Cationic substitution has been proposed to enhance surface stability, thus limiting capacity decay. Here, we demonstrate the stabilizing effect of Mg on the LNMO cathode surface, which is most evident during the early stages of cycling. This study indicates that improved O 2p-TM 3d hybridization in Mg-substituted LNMO, facilitated by Li-site defects, leads to the formation of a stable surface layer that is corrosion-resistant at high voltage. Examination of Fe-substituted and unsubstituted LNMO further confirms that the surface stability is uniquely enabled by Mg substitution. This work offers valuable insights into surface design for reducing degradation in high-voltage spinel cathodes.
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Nov 2025
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I24-Microfocus Macromolecular Crystallography
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Natalia
Venetz-Arenas
,
Tim
Schulte
,
Sandra
Müller
,
Karin
Wallden
,
Stefanie
Fischer
,
Tom
Resink
,
Nadir
Kadri
,
Maria
Paladino
,
Nicole
Pina
,
Filip
Radom
,
Denis
Villemagne
,
Sandra
Bruckmaier
,
Andreas
Cornelius
,
Tanja
Hospodarsch
,
Evren
Alici
,
Hans-Gustaf
Ljunggren
,
Benedict J.
Chambers
,
Xiao
Han
,
Renhua
Sun
,
Marta
Carroni
,
Victor
Levitsky
,
Tatyana
Sandalova
,
Marcel
Walser
,
Adnane
Achour
Diamond Proposal Number(s):
[21625]
Open Access
Abstract: The balance between affinity and specificity in T cell receptor (TCR)-dependent targeting of HLA-restricted tumor-associated antigens presents a significant challenge for immunotherapy development. T cell engagers that circumvent these limitations are therefore of particular interest. We established a process to generate bispecific Designed Ankyrin Repeat Proteins (DARPins) that simultaneously target HLA-I/peptide complexes and CD3e. These high-affinity T cell engagers elicited CD8+ T cell activation against tumor targets with strong peptide specificity, as confirmed by X-scanning mutagenesis and functional killing assays. A cryo-EM structure of the ternary DARPin/HLA-A*0201/NY-ESO1157-165 complex revealed a rigid, concave DARPin surface spanning the full length of the peptide-binding cleft, contacting both α-helices and the peptide. The present findings reveal promising immuno-oncotherapeutic approaches and demonstrate the feasibility of rapidly developing DARPins with high affinity and specificity for HLA/peptide targets, which can be readily combined with a new generation of anti-CD3e-specific DARPins.
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Nov 2025
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B16-Test Beamline
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Diamond Proposal Number(s):
[33032]
Open Access
Abstract: This study presents the first demonstration of the use of X-ray diffraction (XRD) to quantify the radial or transverse deformation in Hexcel IM7 PolyAcryloNitrile (PAN)-based carbon fibres at temperatures as low as 200 K (-70 °C). The Coefficient of Thermal Expansion (CTE) is a critical design parameter that needs to be precisely quantified for the next generation of carbon fibre-based Liquid Hydrogen (
) storage tanks for net-zero aviation. This variable quantitatively describes the thermal mismatch between the fibre and the resin that is the driver for microcracking and tank leakage. However, quantification of the CTE of the fibres is experimentally challenging. The results provide unique insights, indicating that the microscopic transverse CTE of the fibre (
) is equal to 26.2 × 10-6 K-1 and is governed by van der Waals forces, similar to those in the basal c-axis (out-of-plane) direction of graphite and the radial direction of multi-wall carbon nanotubes. Taking into account the microcrack-induced relaxation effect reported in polycrystalline graphite, the macroscopic fibre transverse CTE was determined to be 7.86 × 10-6 K-1. XRD data were also collected on Hexcel IM7/8552 Uni-directional (UD) and Quasi-isotropic (QI) composite laminates to investigate the influence of the interaction of the resin matrix with the fibre lattice and the stacking sequence on the development of thermal fibre lattice strain. In the UD laminate, the presence of resin induces an additional transverse strain in the fibres as a result of resin contraction during cooling, leading to the development of a compressive strain in the fibre direction. This behaviour was found to be in good agreement with numerical simulations, with a 13 % error at the lowest measured temperature. In contrast, the fibres in the QI configuration were reinforced in the transverse direction, effectively mitigating the influence of resin contraction. These CTE values, insights, and resulting models are essential for multi-scale modelling, design and certification of carbon fibre composite
tanks that are required to achieve net-zero aviation.
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Oct 2025
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[32708]
Open Access
Abstract: BCC superalloys are a promising class of high-temperature materials with a wide range of lattice misfit values, ranging from near-zero to ∼8 %. Analogous to nickel superalloys, lattice misfit combined with elastic anisotropy dictates precipitate morphology (spherical, cuboidal, plate/needle-like), coarsening kinetics, strengthening mechanisms, and microstructure evolution, making misfit control critical for tailoring microstructural stability and creep resistance. However, misfit characterisation, especially at high temperatures, is still in its infancy to establish its links with mechanical properties. This perspective emphasises three aspects of BCC superalloys: representative misfit-driven microstructures and temperature-dependent misfit evolution, state-of-the-art diffraction techniques for high-temperature misfit quantification, and machine learning frameworks to accelerate alloy design involving misfit. By consolidating diverse misfit data and advanced characterisation/modelling strategies, we outline strategies to bridge computational and experimental gaps, advocating for physics-informed models and high-throughput techniques to design next-generation BCC superalloys and motivate systematic studies on the misfit-property relationship in this nascent material class.
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Oct 2025
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I18-Microfocus Spectroscopy
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Ian T.
Burke
,
Patrizia
Onnis
,
Alex L.
Riley
,
Catherine J.
Gandy
,
Violeta
Ramos
,
Gavyn K.
Rollinson
,
Patrick
Byrne
,
Richard A.
Crane
,
Karen A.
Hudson-Edwards
,
Elin
Jennings
,
William M.
Mayes
,
J. Frederick W.
Mosselmans
,
Adam P.
Jarvis
Diamond Proposal Number(s):
[29808, 31675]
Open Access
Abstract: The erosion of legacy coastal municipal solid waste landfill sites will result in the dispersion of particulate material into nearby ecosystems with potential for effects on marine populations. Information on the speciation and solid phase associations of metal(loid) contaminants will help to predict contaminant behaviour and better understand ecosystem risks. Here, we investigate the solid phase composition of, and metal(loid) leaching from, fine fraction materials recovered from three actively eroding coastal landfill sites. High concentrations of a range of potentially toxic elements (As, Cd, Cr, Cu, Pb, Ni and Zn) were present in multiple samples, but metal(loid) leaching rates were very low (≪1 wt%) in both deionised water and seawater solutions. Therefore, particulate dispersion is the most likely mode of contaminant transport occurring at these sites. The fine fraction materials were dominated by fine sand sized (63–180 μm) quartz grains and silt sized (<63 μm) matrix components, which were likely to be poorly retained on beaches and easily transported offshore. Four priority contaminants (As, Cu, Pb and Zn) were found to occur primarily in adsorbed or precipitate forms, as either coatings on other particles or as discrete <10 μm particles. Dilution of these fine-grained contaminated particles within natural pelitic sediments will likely reduce the overall ecosystems impacts; but the risks to filter and bottom feeding organisms, and the potential for biomagnification across trophic levels are poorly understood.
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Oct 2025
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B16-Test Beamline
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Diamond Proposal Number(s):
[30528]
Open Access
Abstract: This paper demonstrates a new approach that exploits both lattice strain mapping via Wide Angle X-ray Scattering (WAXS) and Digital Volume Correlation (DVC) of Computed Tomography (CT) to understand the material response at different length scales in Carbon Fibre Reinforced Polymers (CFRPs) under in-situ loading, a phenomenon of substantial importance for the modelling, design, and certification of composite structures. WAXS gives insight into fibre lattice strain, while DVC provides sub-laminate response in the CFRP. A detailed numerical simulation was also developed to compare with these novel experimental methods. This approach is the first demonstration that the strain within the crystalline regions of the fibre is distinct from the sub-laminate behaviour, with up to 80 % and 36 % differences in the longitudinal and transverse directions, respectively, as a result of the complex microstructure of the fibres. An improved understanding of composite behaviour is fundamental to understanding how strain accommodation leads to structural failure, providing routes to refine part rejection criteria and reduce the environmental impact of this increasingly widespread material class.
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Oct 2025
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Beatriz
Costa-Gomes
,
Joel
Greer
,
Nikolai
Juraschko
,
James
Parkhurst
,
Jola
Mirecka
,
Marjan
Famili
,
Camila
Rangel-Smith
,
Oliver
Strickson
,
Alan
Lowe
,
Mark
Basham
,
Tom
Burnley
Open Access
Abstract: Ease of access to data, tools and models expedites scientific research. In structural biology there are now numerous open repositories of experimental and simulated data sets. Being able to easily access and utilize these is crucial to allow researchers to make optimal use of their research effort. The tools presented here are useful for collating existing public cryoEM data sets and/or creating new synthetic cryoEM data sets to aid the development of novel data processing and interpretation algorithms. In recent years, structural biology has seen the development of a multitude of machine-learning-based algorithms to aid numerous steps in the processing and reconstruction of experimental data sets and the use of these approaches has become widespread. Developing such techniques in structural biology requires access to large data sets, which can be cumbersome to curate and unwieldy to make use of. In this paper, we present a suite of Python software packages, which we collectively refer to as PERC (profet, EMPIARreader and CAKED). These are designed to reduce the burden which data curation places upon structural biology research. The protein structure fetcher (profet) package allows users to conveniently download and cleave sequences or structures from the Protein Data Bank or AlphaFold databases. EMPIARreader allows lazy loading of Electron Microscopy Public Image Archive data sets in a machine-learning-compatible structure. The Class Aggregator for Key Electron-microscopy Data (CAKED) package is designed to seamlessly facilitate the training of machine-learning models on electron microscopy data, including electron-cryo-microscopy-specific data augmentation and labeling. These packages may be utilized independently or as building blocks in workflows. All are available in open-source repositories and designed to be easily extensible to facilitate more advanced workflows if required.
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Oct 2025
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