I12-JEEP: Joint Engineering, Environmental and Processing
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Nolwenn
Le Gall
,
Fabio
Arzilli
,
Giuseppe
La Spina
,
Margherita
Polacci
,
Biao
Cai
,
Margaret E.
Hartley
,
Nghia T.
Vo
,
Robert C.
Atwood
,
Danilo
Di Genova
,
Sara
Nonni
,
Edward W.
Llewellin
,
Mike R.
Burton
,
Peter D.
Lee
Diamond Proposal Number(s):
[12392]
Abstract: Crystallisation is a complex process that significantly affects the rheology of magma, and thus the flow dynamics during a volcanic eruption. For example, the evolution of crystal fraction, size and shape has a strong impact on the surface crust formation of a lava flow, and accessing such information is essential for accurate modelling of lava flow dynamics. To investigate the role of crystallisation kinetics on lava flow behaviour, we performed real-time, in situ synchrotron X-ray microtomography, studying the influence of temperature-time paths on the nucleation and growth of clinopyroxene and plagioclase in an oxidised, nominally anhydrous basaltic magma. Crystallisation experiments were performed at atmospheric pressure in air and temperatures from 1250 °C to 1100 °C, using a bespoke high-temperature resistance furnace. Depending on the cooling regime (single step versus continuous), two different crystal phases (either clinopyroxene or plagioclase) were produced, and we quantified their growth from both global and individual 3D texture analyses. The textural evolution of charges suggests that suppression of crystal nucleation is due to changes in the melt composition with increasing undercooling and time. Using existing viscosity models, we inferred the effect of crystals on the viscosity evolution of our crystal-bearing samples to trace changes in rheological behaviour during lava emplacement. We observe that under continuous cooling, both the onsets of the pāhoehoe-‘a‘ā transition and of non-Newtonian behaviour occur within a shorter time frame. With varying both temperature and time, we also either reproduced or approached the clinopyroxene and plagioclase phenocryst abundances and compositions of the Etna lava used as starting material, demonstrating that real-time synchrotron X-ray tomography is an ideal approach to unravel the final solidification history of basaltic lavas. This imaging technology has indeed the potential to provide input into lava flow models and hence our ability to forecast volcanic hazards.
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Aug 2021
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[22299]
Open Access
Abstract: As a result of the synthesis protocol polyoxyethylene sorbitan monooleate (polysorbate 80, PS80) is a highly complex mixture of compounds. PS80 was therefore separated into its main constituents, e.g. polyoxyethylene isosorbide esters and polyoxyethylene esters, as well as mono- di- and polyesters using preparative high-performance liquid chromatography. In this comprehensive study the individual components and their ethoxylation level were verified by matrix assisted laser desorption/ionization time-of-flight and their thermotropic behavior was analyzed using differential scanning calorimetry and X-ray diffraction. A distinct correlation was found between the average length of the ethylene oxide (EO) chains in the headgroup and the individual compounds’ ability to crystallize. Importantly, a critical number of EO units required for crystallization of the headgroup was determined (6 EO units per chain or 24 per molecule). The investigation also revealed that the hydrocarbon tails only crystallize for polyoxyethylene sorbitan esters if saturated. PS80 is synthesized by reacting with approximately 20 mol of EO per mole of sorbitol, however, the number of EO units in the sorbitan ester in commercial PS80 products is higher than the expected 20 (5 EO units per chain). The complex behavior of all tested compounds revealed that if the amount of several of the linear by-products is reduced, the number of EO units in the chains will stay below the critical number and the product will not be able to crystallize by the EO chains.
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Jun 2021
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B22-Multimode InfraRed imaging And Microspectroscopy
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Philip A.
Ash
,
Sophie E. T.
Kendall-Price
,
Rhiannon M.
Evans
,
Stephen
Carr
,
Amelia
Brasnett
,
Simone
Morra
,
Ricardo
Hidalgo
,
Adam J.
Healy
,
Gianfelice
Cinque
,
Mark D.
Frogley
,
Fraser A
Armstrong
,
Kylie A.
Vincent
Diamond Proposal Number(s):
[17753, 19269, 21651]
Open Access
Abstract: Controlled formation of catalytically-relevant states within crystals of complex metalloenzymes represents a significant challenge to structure-function studies. Here we show how electrochemical control over single crystals of [NiFe] hydrogenase 1 (Hyd1) from Escherichia coli makes it possible to navigate through the full array of active site states previously observed in solution. Electrochemical control is combined with synchrotron infrared microspectroscopy, which enables us to measure high signal-to-noise IR spectra in situ from a small area of crystal. The output reports on active site speciation via the vibrational stretching band positions of the endogenous CO and CN- ligands at the hydrogenase active site. Variation of pH further demonstrates how equilibria between catalytically-relevant protonation states can be deliberately perturbed in the crystals, generating a map of electrochemical potential and pH conditions which lead to enrichment of specific states. Comparison of in crystallo redox titrations with measurements in solution or of electrode-immobilised Hyd1 confirms the integrity of the proton transfer and redox environment around the active site of the enzyme in crystals. Slowed proton-transfer equilibria in the hydrogenase in crystallo reveals transitions which are only usually observable by ultrafast methods in solution. This study therefore demonstrates the possibilities of electrochemical control over single metalloenzyme crystals in stabilising specific states for further study, and extends mechanistic understanding of proton transfer during the [NiFe] hydrogenase catalytic cycle.
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Jun 2021
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I08-Scanning X-ray Microscopy beamline (SXM)
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James
Everett
,
Frederik
Lermyte
,
Jake
Brooks
,
Vindy
Tjendana-Tjhin
,
Germán
Plascencia-Villa
,
Ian
Hands-Portman
,
Jane M.
Donnelly
,
Kharmen
Billimoria
,
George
Perry
,
Xiongwei
Zhu
,
Peter J.
Sadler
,
Peter B.
O'Connor
,
Joanna F.
Collingwood
,
Neil D.
Telling
Diamond Proposal Number(s):
[15854]
Open Access
Abstract: The chemistry of copper and iron plays a critical role in normal brain function. A variety of enzymes and proteins containing positively charged Cu+, Cu2+, Fe2+, and Fe3+ control key processes, catalyzing oxidative metabolism and neurotransmitter and neuropeptide production. Here, we report the discovery of elemental (zero–oxidation state) metallic Cu0 accompanying ferromagnetic elemental Fe0 in the human brain. These nanoscale biometal deposits were identified within amyloid plaque cores isolated from Alzheimer’s disease subjects, using synchrotron x-ray spectromicroscopy. The surfaces of nanodeposits of metallic copper and iron are highly reactive, with distinctly different chemical and magnetic properties from their predominant oxide counterparts. The discovery of metals in their elemental form in the brain raises new questions regarding their generation and their role in neurochemistry, neurobiology, and the etiology of neurodegenerative disease.
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Jun 2021
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Krios I-Titan Krios I at Diamond
Krios II-Titan Krios II at Diamond
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Andreas
Schedlbauer
,
Idoia
Iturrioz
,
Borja
Ochoa-Lizarralde
,
Tammo
Diercks
,
Jorge Pedro
Lopez-Alonso
,
José Luis
Lavin
,
Tatsuya
Kaminishi
,
Retina
Çapuni
,
Neha
Dhimole
,
Elisa
De Astigarraga
,
David
Gil-Carton
,
Paola
Fucini
,
Sean R.
Connell
Diamond Proposal Number(s):
[17171, 15422]
Open Access
Abstract: While a structural description of the molecular mechanisms guiding ribosome assembly in eukaryotic systems is emerging, bacteria use an unrelated core set of assembly factors for which high-resolution structural information is still missing. To address this, we used single-particle cryo–electron microscopy to visualize the effects of bacterial ribosome assembly factors RimP, RbfA, RsmA, and RsgA on the conformational landscape of the 30S ribosomal subunit and obtained eight snapshots representing late steps in the folding of the decoding center. Analysis of these structures identifies a conserved secondary structure switch in the 16S ribosomal RNA central to decoding site maturation and suggests both a sequential order of action and molecular mechanisms for the assembly factors in coordinating and controlling this switch. Structural and mechanistic parallels between bacterial and eukaryotic systems indicate common folding features inherent to all ribosomes.
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Jun 2021
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I19-Small Molecule Single Crystal Diffraction
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Diamond Proposal Number(s):
[23404]
Abstract: (S)-(−)-1-Phenylethanaminium 4-(2,4,6-triisopropylbenzoyl)benzoate (S-PEATPBB) undergoes a photochemical reaction in its crystalline form upon UV irradiation and forms three different products: the first product is the result of a Yang cyclization with the participation of the δ-H atom of o-isopropyl (product D) and the second and third products are obtained via a Norrish–Yang reaction with the involvement of the γ-H atom of 2-isopropyl (product P) and 6-isopropyl (product Z). These products are formed in different proportions (D > P >> Z). The path and kinetics of the reaction were monitored step-by-step using crystallographic methods, both under ambient and high-pressure conditions. The reactivity of S-PEATPBB depends strongly on the geometry of the reaction centre and the volume of the reaction cavity. Due to the geometrical preferences making the cyclization reaction easier to proceed, product D dominates over the other products, while the formation of product Z becomes difficult or almost impossible at high pressure. The reaction proceeds with an increase of the unit-cell volume, which, suppressed by high pressure, results in a significant decrease of the reaction rate. The crystal lattice of S-PEATPBB shows high elasticity. The quality of the partially reacted crystal remains the same after decompression from 0.75 GPa to 0.1 MPa.
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Jun 2021
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[22176]
Abstract: Hypothesis: Despite the widespread industrial usage of erucamide as a slip additive to modify polymer surface properties, a controversy appears to have persisted regarding the nanostructure of erucamide surface layers, particularly the molecular orientation at the outermost layer. The erucamide nanostructure and molecular orientation, along with its surface coverage, hydrophobicity, and adhesive response, can be tuned by simply varying the erucamide concentration in the solution from which the spin coated layer is prepared. Experiments: Synchrotron X-ray reflectivity (XRR) allowed a comprehensive characterisation of the out-of-plane structural parameters (e.g. molecular packing and thickness) of the erucamide layers prepared via spin coating from nonaqueous solution on silica. Complementary Atomic Force Microscopy (AFM) imaging with high lateral resolution revealed localised in-plane structures. Contact angle measurements provided information on the wettability of erucamide-coated surfaces. Peak Force Quantitative Nanomechanical Mapping (QNM) allowed a correlation between the erucamide nanostructure with the surface nanomechanical properties (i.e. adhesive response). Findings: Our results reveal erucamide surface nanostructures on silica as patchy monolayers, isolated circular bilayers/rounded rectangle-like aggregates and overlapping plate-like multilayers as the erucamide concentration in the spin coating solution was varied. In all the cases, XRR and AFM results were consistent with the picture that the erucamide tails were oriented outwards. The QNM adhesion force mapping of all the observed morphologies also supported this molecular orientation at the outermost erucamide monolayer. The wettability study further confirmed this conclusion with the observed increase in the surface hydrophobicity and coverage upon increasing erucamide concentration, with the macroscopic water contact angle θ = 92.9° ± 2.9° at the highest erucamide concentration of 2 wt%.
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May 2021
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B18-Core EXAFS
E01-JEM ARM 200CF
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Diamond Proposal Number(s):
[20856]
Open Access
Abstract: Coinage metal nanoparticles with high dispersion can serve as highly efficient heterogeneous catalysts. However, owing to their low melting point, poor thermal stability remains a major obstacle towards their application under reaction conditions. It is a common practice to use porous inorganic templates such as mesoporous silica SBA-15 to disperse Ag nanoparticles (NPs) against aggregation but their stability is far from satisfactory. Here, we show that the catalytic activity for hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG) over Ag NPs dispersed on SBA-15 silica can be further promoted by incorporation of alkali metal ions at small loading, which follows the inverse order of their cationic size: Li+ > Na+ > K+ > Rb+. Among these, 5Ag1–Li0.05/SBA-15 can double the MG yield compared to pristine 5Ag/SBA-15 under identical conditions with superior thermal stability. Akin to the effect of an ionic surfactant on stabilization of a micro-emulsion, the cationic charge of an alkali metal ion can maintain dispersion and modulate the surface valence of Ag NPs. Interstitial Li in the octahedral holes of the face center packed Ag lattice is for the first time confirmed by X-ray pair distribution function and electron ptychography. It is believed that this interstitial-stabilization of coinage metal nanoparticles could be broadly applicable to multi-metallic nanomaterials for a broad range of C–O bond activating catalytic reactions of esters.
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May 2021
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B18-Core EXAFS
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Siyu
Zhao
,
Ruikuan
Xie
,
Liqun
Kang
,
Manni
Yang
,
Xingyu
He
,
Wenyao
Li
,
Ryan
Wang
,
Dan J. L.
Brett
,
Guanjie
He
,
Guoliang
Chai
,
Ivan P.
Parkin
Diamond Proposal Number(s):
[19850]
Open Access
Abstract: It remains a challenge to develop efficient electrocatalysts in neutral media for hydrogen evolution reaction (HER) due to the sluggish kinetics and switch of the rate determining step. Although metal phosphides are widely used HER catalysts, their structural stability is an issue due to oxidization, and the HER performance in neutral media requires improvement. Herein, a new material, i.e., grapevine‐shaped N‐doped iron phosphide on carbon nanotubes, as an efficient HER catalyst in neutral media is developed. The optimized catalyst shows an overpotential of 256 mV at a large current density of 65 mA cm−2, which is even 10 mV lower than that of the commercial 20% Pt/C catalyst. The excellent performance of the catalyst is further studied by combined computational and experimental techniques, which proves that the interaction between nitrogen and iron phosphides can provide more efficient active structures and stabilize the metal phosphide electrocatalysts for HER.
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May 2021
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Sebastian
Gunther
,
Patrick Y. A.
Reinke
,
Yaiza
Fernández-García
,
Julia
Lieske
,
Thomas J.
Lane
,
Helen M.
Ginn
,
Faisal H. M.
Koua
,
Christiane
Ehrt
,
Wiebke
Ewert
,
Dominik
Oberthuer
,
Oleksandr
Yefanov
,
Susanne
Meier
,
Kristina
Lorenzen
,
Boris
Krichel
,
Janine-Denise
Kopicki
,
Luca
Gelisio
,
Wolfgang
Brehm
,
Ilona
Dunkel
,
Brandon
Seychell
,
Henry
Gieseler
,
Brenna
Norton-Baker
,
Beatriz
Escudero-Pérez
,
Martin
Domaracky
,
Sofiane
Saouane
,
Alexandra
Tolstikova
,
Thomas A.
White
,
Anna
Hänle
,
Michael
Groessler
,
Holger
Fleckenstein
,
Fabian
Trost
,
Marina
Galchenkova
,
Yaroslav
Gevorkov
,
Chufeng
Li
,
Salah
Awel
,
Ariana
Peck
,
Miriam
Barthelmess
,
Frank
Schluenzen
,
Paulraj
Lourdu Xavier
,
Nadine
Werner
,
Hina
Andaleeb
,
Najeeb
Ullah
,
Sven
Falke
,
Vasundara
Srinivasan
,
Bruno Alves
França
,
Martin
Schwinzer
,
Hévila
Brognaro
,
Cromarte
Rogers
,
Diogo
Melo
,
Joanna J.
Zaitseva-Doyle
,
Juraj
Knoska
,
Gisel E.
Peña-Murillo
,
Aida Rahmani
Mashhour
,
Vincent
Hennicke
,
Pontus
Fischer
,
Johanna
Hakanpää
,
Jan
Meyer
,
Philip
Gribbon
,
Bernhard
Ellinger
,
Maria
Kuzikov
,
Markus
Wolf
,
Andrea R.
Beccari
,
Gleb
Bourenkov
,
David
Von Stetten
,
Guillaume
Pompidor
,
Isabel
Bento
,
Saravanan
Panneerselvam
,
Ivars
Karpics
,
Thomas R.
Schneider
,
Maria Marta
Garcia-Alai
,
Stephan
Niebling
,
Christian
Günther
,
Christina
Schmidt
,
Robin
Schubert
,
Huijong
Han
,
Juliane
Boger
,
Diana C. F.
Monteiro
,
Linlin
Zhang
,
Xinyuanyuan
Sun
,
Jonathan
Pletzer-Zelgert
,
Jan
Wollenhaupt
,
Christian G.
Feiler
,
Manfred S.
Weiss
,
Eike-Christian
Schulz
,
Pedram
Mehrabi
,
Katarina
Karničar
,
Aleksandra
Usenik
,
Jure
Loboda
,
Henning
Tidow
,
Ashwin
Chari
,
Rolf
Hilgenfeld
,
Charlotte
Uetrecht
,
Russell
Cox
,
Andrea
Zaliani
,
Tobias
Beck
,
Matthias
Rarey
,
Stephan
Günther
,
Dusan
Turk
,
Winfried
Hinrichs
,
Henry N.
Chapman
,
Arwen R.
Pearson
,
Christian
Betzel
,
Alke
Meents
Open Access
Abstract: The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous human suffering. To date, no effective drug is available to directly treat the disease. In a search for a drug against COVID-19, we have performed a high-throughput X-ray crystallographic screen of two repurposing drug libraries against the SARS-CoV-2 main protease (Mpro), which is essential for viral replication. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds that bind to Mpro. In subsequent cell-based viral reduction assays, one peptidomimetic and six non-peptidic compounds showed antiviral activity at non-toxic concentrations. We identified two allosteric binding sites representing attractive targets for drug development against SARS-CoV-2.
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Apr 2021
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