I08-Scanning X-ray Microscopy beamline (SXM)
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Karin
Eusterhues
,
Juergen
Thieme
,
Sneha
Narvekar
,
Tohru
Araki
,
Majid
Kazemian
,
Burkhard
Kaulich
,
Tom
Regier
,
Jian
Wang
,
Johann
Lugmeier
,
Carmen
Höschen
,
Tim
Mansfeldt
,
Kai Uwe
Totsche
Diamond Proposal Number(s):
[18569]
Abstract: Sorption of organic molecules on mineral surfaces can occur through several binding mechanisms of varying strength. Here, we investigated the importance of inner-sphere P-O-Fe bonds in synthetic and natural mineral-organic associations. Natural organic matter such as water extracted soil organic matter (WESOM) and extracellular polymeric substances (EPS) from liquid bacterial cultures were adsorbed to goethite and examined by FTIR spectroscopy and P K-edge NEXAFS spectroscopy. Natural particles from a Bg soil horizon (Gleysol) were subjected to X-ray fluorescence (XRF) mapping, NanoSIMS imaging, and NEXAFS spectro-microscopy at the P K-edge. Inner-sphere P-O-Fe bonds were identified for both, adsorbed EPS extracts and adsorbed WESOMs. Characteristic infrared peaks for P-O-Fe stretching vibrations are present but cannot unambiguously be interpreted due to possible interferences with mono- and polysaccharides. For the Bg horizon, P was only found on Fe oxides, covering the entire surface at different concentrations, but not on clay minerals. Linear combination fitting of NEXAFS spectra indicates that this adsorbed P is mainly a mixture of orthophosphate and organic P compounds. By combining atomic force microscopy (AFM) images with STXM-generated C and Fe distribution maps, we show that the Fe oxide surfaces were fully coated with organic matter. In contrast, clay minerals revealed a much lower C signal. The C NEXAFS spectra taken on the Fe oxides had a substantial contribution of carboxylic C, aliphatic C, and O-alkyl C, which is a composition clearly different from pure adsorbed EPS or aromatic-rich lignin-derived compounds. Our data show that inner-sphere P-O-Fe bonds are important for the association of Fe oxides with soil organic matter. In the Bg horizon, carboxyl groups and orthophosphate compete with the organic P compounds for adsorption sites.
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Sep 2023
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I08-Scanning X-ray Microscopy beamline (SXM)
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Oliver W.
Moore
,
Lisa
Curti
,
Clare
Woulds
,
James A.
Bradley
,
Peyman
Babakhani
,
Benjamin J. W.
Mills
,
William B.
Homoky
,
Ke-Qing
Xiao
,
Andrew W.
Bray
,
Ben J.
Fisher
,
Majid
Kazemian
,
Burkhard
Kaulich
,
Andrew W.
Dale
,
Caroline L.
Peacock
Diamond Proposal Number(s):
[18560, 21323]
Open Access
Abstract: The balance between degradation and preservation of sedimentary organic carbon (OC) is important for global carbon and oxygen cycles1. The relative importance of different mechanisms and environmental conditions contributing to marine sedimentary OC preservation, however, remains unclear2,3,4,5,6,7,8. Simple organic molecules can be geopolymerized into recalcitrant forms by means of the Maillard reaction5, although reaction kinetics at marine sedimentary temperatures are thought to be slow9,10. More recent work in terrestrial systems suggests that the reaction can be catalysed by manganese minerals11,12,13, but the potential for the promotion of geopolymerized OC formation at marine sedimentary temperatures is uncertain. Here we present incubation experiments and find that iron and manganese ions and minerals abiotically catalyse the Maillard reaction by up to two orders of magnitude at temperatures relevant to continental margins where most preservation occurs4. Furthermore, the chemical signature of the reaction products closely resembles dissolved and total OC found in continental margin sediments globally. With the aid of a pore-water model14, we estimate that iron- and manganese-catalysed transformation of simple organic molecules into complex macromolecules might generate on the order of approximately 4.1 Tg C yr−1 for preservation in marine sediments. In the context of perhaps only about 63 Tg C yr−1 variation in sedimentary organic preservation over the past 300 million years6, we propose that variable iron and manganese inputs to the ocean could exert a substantial but hitherto unexplored impact on global OC preservation over geological time.
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Aug 2023
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I08-Scanning X-ray Microscopy beamline (SXM)
I09-Surface and Interface Structural Analysis
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Diamond Proposal Number(s):
[1860, 20639, 22619]
Open Access
Abstract: Li3N is an excellent protective coating material for lithium electrodes with very high lithium-ion conductivity and low electronic conductivity, but the formation of stable and homogeneous coatings is technically very difficult. Here, we show that protective Li3N coatings can be simply formed by the direct reaction of electrodeposited lithium electrodes with N2 gas, whereas using battery-grade lithium foil is problematic due to the presence of a native passivation layer that hampers that reaction. The protective Li3N coating is effective at preventing lithium dendrite formation, as found from unidirectional plating and plating–stripping measurements in Li–Li cells. The Li3N coating also efficiently suppresses the parasitic reactions of polysulfides and other electrolyte species with the lithium electrode, as demonstrated by scanning transmission X-ray microscopy, X-ray photoelectron spectroscopy, and optical microscopy. The protection of the lithium electrode against corrosion by polysulfides and other electrolyte species, as well as the promotion of smooth deposits without dendrites, makes the Li3N coating highly promising for applications in lithium metal batteries, such as lithium–sulfur batteries. The present findings show that the formation of Li3N can be achieved with lithium electrodes covered by a secondary electrolyte interface layer, which proves that the in situ formation of Li3N coatings inside the batteries is attainable.
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Aug 2023
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E01-JEM ARM 200CF
I08-Scanning X-ray Microscopy beamline (SXM)
I13-2-Diamond Manchester Imaging
I14-Hard X-ray Nanoprobe
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Cyril
Besnard
,
Ali
Marie
,
Sisini
Sasidharan
,
Petr
Buček
,
Jessica M.
Walker
,
Julia E.
Parker
,
Matthew C.
Spink
,
Robert A.
Harper
,
Shashidhara
Marathe
,
Kaz
Wanelik
,
Thomas E. J.
Moxham
,
Enrico
Salvati
,
Konstantin
Ignatyev
,
Michal M.
Klosowski
,
Richard M.
Shelton
,
Gabriel
Landini
,
Alexander M.
Korsunsky
Diamond Proposal Number(s):
[27749, 30684, 30691, 31005, 29256, 23873]
Open Access
Abstract: Caries, a major global disease associated with dental enamel demineralization, remains insufficiently understood to devise effective prevention or minimally invasive treatment. Understanding the ultrastructural changes in enamel is hampered by a lack of nanoscale characterization of the chemical spatial distributions within the dental tissue. This leads to the requirement to develop techniques based on various characterization methods. The purpose of the present study is to demonstrate the strength of analytic methods using a correlative technique on a single sample of human dental enamel as a specific case study to test the accuracy of techniques to compare regions in enamel. The science of the different techniques is integrated to genuinely study the enamel. The hierarchical structures within carious tissue were mapped using the combination of focused ion beam scanning electron microscopy with synchrotron X-ray tomography. The chemical changes were studied using scanning X-ray fluorescence (XRF) and X-ray wide-angle and small-angle scattering using a beam size below 80 nm for ångström and nanometer length scales. The analysis of XRF intensity gradients revealed subtle variations of Ca intensity in carious samples in comparison with those of normal mature enamel. In addition, the pathways for enamel rod demineralization were studied using X-ray ptychography. The results show the chemical and structural modification in carious enamel with differing locations. These results reinforce the need for multi-modal approaches to nanoscale analysis in complex hierarchically structured materials to interpret the changes of materials. The approach establishes a meticulous correlative characterization platform for the analysis of biomineralized tissues at the nanoscale, which adds confidence in the interpretation of the results and time-saving imaging techniques. The protocol demonstrated here using the dental tissue sample can be applied to other samples for statistical study and the investigation of nanoscale structural changes. The information gathered from the combination of methods could not be obtained with traditional individual techniques.
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Jul 2023
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I08-Scanning X-ray Microscopy beamline (SXM)
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Diamond Proposal Number(s):
[15230, 24534, 29042, 30776]
Open Access
Abstract: The synchrotron x-ray spectromicroscopy technique Scanning Transmission X-ray Microscopy (STXM) offers a powerful means to examine the underlying biochemistry of biological systems, owing to its combined chemical sensitivity and nanoscale spatial resolution. Here we introduce and demonstrate methodology for the use of STXM to examine the biochemistry of the human brain. We then discuss how this approach can help us better understand the biochemical changes that occur during the development of degenerative brain disorders, potentially facilitating the development of new therapies for disease diagnosis and treatment.
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Jun 2023
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B16-Test Beamline
DIAD-Dual Imaging and Diffraction Beamline
E01-JEM ARM 200CF
E02-JEM ARM 300CF
I08-Scanning X-ray Microscopy beamline (SXM)
I12-JEEP: Joint Engineering, Environmental and Processing
I13-1-Coherence
I13-2-Diamond Manchester Imaging
I14-Hard X-ray Nanoprobe
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Open Access
Abstract: Hard dental tissues possess a complex hierarchical structure that is particularly evident in enamel, the most mineralised substance in the human body. Its complex and interlinked organisation at the Ångstrom (crystal lattice), nano-, micro-, and macro-scales is the result of evolutionary optimisation for mechanical and functional performance: hardness and stiffness, fracture toughness, thermal, and chemical resistance. Understanding the physical–chemical–structural relationships at each scale requires the application of appropriately sensitive and resolving probes. Synchrotron X-ray techniques offer the possibility to progress significantly beyond the capabilities of conventional laboratory instruments, i.e., X-ray diffractometers, and electron and atomic force microscopes. The last few decades have witnessed the accumulation of results obtained from X-ray scattering (diffraction), spectroscopy (including polarisation analysis), and imaging (including ptychography and tomography). The current article presents a multi-disciplinary review of nearly 40 years of discoveries and advancements, primarily pertaining to the study of enamel and its demineralisation (caries), but also linked to the investigations of other mineralised tissues such as dentine, bone, etc. The modelling approaches informed by these observations are also overviewed. The strategic aim of the present review was to identify and evaluate prospective avenues for analysing dental tissues and developing treatments and prophylaxis for improved dental health.
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Apr 2023
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I08-Scanning X-ray Microscopy beamline (SXM)
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Abstract: In this thesis, the bioconversion of palladium and ruthenium solutions into valuable monometallic and bimetallic nanoparticles with highly catalytic activity is described. Bacteria can enzymatically reduce Pd(II) at the expense of an exogenous electron donor to Pd(0). The resulting nanoparticles (NPs) are immobilised in the cytoplasm, membrane and periplasm of the cells resulting in small NPs with a homogeneous size and high catalytic properties. The catalytic activity of the biogenic Pd NPs is sometimes higher than the commercial catalysts with the additional advantage of being synthesized using more economic and environmentally friendly methodologies. Previous studies have shown the ability of some bacteria to recover gold and palladium from wastes using cells of Escherichia coli and Desulfovibrio desulfuricans and have elucidated some of the main enzymes involve in the initial nucleation and formation of Pd NPs. Other studies proved the ability of bacteria to synthesize bimetallic NPs of gold and palladium and palladium and ruthenium.
In this study, cells of E. coli were used for the synthesis of bimetallic NPs of Pd/Ru. A detailed information of the structure of the bimetallic NPs was provided using a combination of spectroscopic and microscopic techniques; a “core/shell” (Ru core, Pd shell) structure was reported with a similar mechanism to that reported previously by Deplanche et al., (2012) with E. coli Pd/Au NPs. In addition, the catalytic properties of the bio-bimetallic NPs were reported for the conversion of 5-hydroxymethylfurfural (5-HMF) (a waste compound derived from the hydrolysis of starch and cellulose for obtaining biofuel) into 2,5-dimethylfuran (2,5-DMF), a valuable compound with similar properties to ethanol, with onward application as biodiesel. The ability to synthesize Pd/Ru NPs was tested using a consortium of acidophilic sulfidogenic (CAS) waste culture recovered from an unrelated biotechnology process together with a traditional sulfidogenic bacterium (D. desulfuricans). D. desulfuricans and CAS culture showed high activity for the conversion of 5-HMF into 2,5-DMF.
Finally, an external source of radio-frequency (RF) (microwave energy (MW)) was applied to resting cells (i.e. before being exposed to Pd(II) solution) of E. coli and D. desulfuricans reporting changes in the dispersity of the resulted Pd NPs compared with untreated cells. The catalytic activity of Pd-NPs on MW-pretreated cells of D. desulfuricans was tested for the hydrogenation of 2-pentyne, showing increased catalytic properties as compared to Pd-NPs on untreated cells.
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Mar 2023
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I08-Scanning X-ray Microscopy beamline (SXM)
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Open Access
Abstract: Scanning transmission X-ray microscopy (STXM) provides the imaging of biological specimens allowing the parallel collection of localized spectroscopic information by X-ray fluorescence (XRF) and/or X-ray Absorption Near Edge Spectroscopy (XANES). The complex metabolic mechanisms which can take place in biological systems can be explored by these techniques by tracing even small quantities of the chemical elements involved in the metabolic pathways. Here, we present a review of the most recent publications in the synchrotrons’ scenario where soft X-ray spectro-microscopy has been employed in life science as well as in environmental research.
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Feb 2023
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I08-Scanning X-ray Microscopy beamline (SXM)
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Christina L.
Davis
,
Ryan A.
Venturelli
,
Alexander B.
Michaud
,
Jon R.
Hawkings
,
Amanda M.
Achberger
,
Trista J.
Vick-Majors
,
Brad E.
Rosenheim
,
John E.
Dore
,
August
Steigmeyer
,
Joel D.
Barker
,
Liane G.
Benning
,
Matthew R.
Siegfried
,
John C.
Priscu
,
Brent C.
Christner
,
Carlo
Barbante
,
Mark
Bowling
,
Justin
Burnett
,
Timothy
Campbell
,
Billy
Collins
,
Cindy
Dean
,
Dennis
Duling
,
Helen A.
Fricker
,
Alan
Gagnon
,
Christopher
Gardner
,
Dar
Gibson
,
Chloe
Gustafson
,
David
Harwood
,
Jonas
Kalin
,
Kathy
Kasic
,
Ok-Sun
Kim
,
Edwin
Krula
,
Amy
Leventer
,
Wei
Li
,
W. Berry
Lyons
,
Patrick
Mcgill
,
James
Mcmanis
,
David
Mcpike
,
Anatoly
Mironov
,
Molly
Patterson
,
Graham
Roberts
,
James
Rot
,
Cathy
Trainor
,
Martyn
Tranter
,
John
Winans
,
Bob
Zook
,
Mark L.
Skidmore
Diamond Proposal Number(s):
[25828]
Open Access
Abstract: Ice streams that flow into Ross Ice Shelf are underlain by water-saturated sediments, a dynamic hydrological system, and subglacial lakes that intermittently discharge water downstream across grounding zones of West Antarctic Ice Sheet (WAIS). A 2.06 m composite sediment profile was recently recovered from Mercer Subglacial Lake, a 15 m deep water cavity beneath a 1087 m thick portion of the Mercer Ice Stream. We examined microbial abundances, used 16S rRNA gene amplicon sequencing to assess community structures, and characterized extracellular polymeric substances (EPS) associated with distinct lithologic units in the sediments. Bacterial and archaeal communities in the surficial sediments are more abundant and diverse, with significantly different compositions from those found deeper in the sediment column. The most abundant taxa are related to chemolithoautotrophs capable of oxidizing reduced nitrogen, sulfur, and iron compounds with oxygen, nitrate, or iron. Concentrations of dissolved methane and total organic carbon together with water content in the sediments are the strongest predictors of taxon and community composition. δ¹³C values for EPS (−25 to −30‰) are consistent with the primary source of carbon for biosynthesis originating from legacy marine organic matter. Comparison of communities to those in lake sediments under an adjacent ice stream (Whillans Subglacial Lake) and near its grounding zone provide seminal evidence for a subglacial metacommunity that is biogeochemically and evolutionarily linked through ice sheet dynamics and the transport of microbes, water, and sediments beneath WAIS.
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Jan 2023
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I08-Scanning X-ray Microscopy beamline (SXM)
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Diamond Proposal Number(s):
[26072]
Open Access
Abstract: Pseudanabaena dominates cyanobacterial blooms in the First-Generation Magnox Storage Pond (FGMSP) at a UK nuclear site. The fission product Cs is a radiologically significant radionuclide in the pond, and understanding the interactions between Cs and Pseudanabaena spp. is therefore important for determining facility management strategies, as well as improving understanding of microbiological responses to this non-essential chemical analogue of K. This study evaluated the fate of Cs following interactions with Pseudanabaena catenata, a laboratory strain most closely related to that dominating FGMSP blooms. Experiments showed that Cs (1 mM) exposure did not affect the growth of P. catenata, while a high concentration of K (5 mM) caused a significant reduction in cell yield. Scanning transmission X-ray microscopy elemental mapping identified Cs accumulation to discrete cytoplasmic locations within P. catenata cells, indicating a potential bioremediation option for Cs. Proteins related to stress responses and nutrient limitation (K, P) were stimulated by Cs treatment. Furthermore, selected K+ transport proteins were mis-regulated by Cs dosing, which indicates the importance of the K+ transport system for Cs accumulation. These findings enhance understanding of Cs fate and biological responses within Pseudanabaena blooms, and indicate that K exposure might provide a microbial bloom control strategy.
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Dec 2022
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