I22-Small angle scattering & Diffraction
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Qian
Ma
,
Andri K.
Riau
,
Robert D.
Young
,
James S.
Bell
,
Olga
Shebanova
,
Nicholas J.
Terrill
,
Gary H. F.
Yam
,
Evelina
Han
,
Keith M.
Meek
,
Jodhbir S.
Mehta
,
Craig
Boote
Diamond Proposal Number(s):
[23514, 28285, 29862, 34903]
Open Access
Abstract: Purpose: Donor tissue shortfalls and postsurgical complications are driving novel corneal tissue regeneration approaches. Corneal stromal keratocytes (CSKs) have shown promise in promoting corneal repair and restoring transparency. We investigated the impact of intrastromal CSK injection on corneal ultrastructure and proteoglycan (PG) distribution in a rat injury model.
Methods: Rats were divided into four groups: normal (n = 12), injured (irregular phototherapeutic keratectomy centrally; n = 6), CSK (injured + human CSK intrastromal injection; n = 6), and PBS (injured + PBS injection; n = 6). Three weeks after treatment, corneas were examined by slit-lamp and optical coherence tomography. Corneal ultrastructure was analysed via small-angle x-ray scattering (collagen fibril diameter, interfibrillar spacing and matrix order), transmission electron microscopy with cuprolinic blue before and after chondroitinase digestion (CS/DS and KS PGs), and immunofluorescence staining (lumican and decorin).
Results: Irregular phototherapeutic keratectomy caused corneal opacity and significantly disrupted stromal ultrastructure, characterized by increased haze density (P < 0.0001), change in central corneal thickness (P = 0.0005), and interfibrillar spacing (P < 0.0001), along with decreased fibril diameter (P < 0.0001), matrix order (P < 0.0001), CS/DS (P < 0.0001) and KS (P < 0.0001) PGs, lumican, and decorin. CSK injection recovered corneal clarity and native stromal ultrastructure, with haze density (P = 0.8086), change in central corneal thickness (P = 0.9503), fibril diameter (P = 0.1139), interfibrillar spacing (P = 0.5879), matrix order (P = 0.9999), CS/DS (P = 0.9969) and KS (P = 0.2877) PGs, lumican, and decorin returning to normal. In contrast, the PBS group exhibited similar corneal injury responses to the injured group.
Conclusions: CSK injection resolved early stage corneal scarring by restoring stromal collagen arrangement and PG distribution, further endorsing its potential for treating corneal opacities.
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Feb 2025
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I22-Small angle scattering & Diffraction
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Adelaide
Lerebours
,
Justyn
Regini
,
Roy A.
Quinlan
,
Toshihiro
Wada
,
Barbara
Pierscionek
,
Martin
Devonshire
,
Alexia A.
Kalligeraki
,
Alice
Uwineza
,
Laura
Young
,
John M.
Girkin
,
Phil
Warwick
,
Kurt
Smith
,
Masato
Hoshino
,
Kentaro
Uesugi
,
Naoto
Yagi
,
Nick
Terrill
,
Olga
Shebanova
,
Tim
Snow
,
Jim T.
Smith
Diamond Proposal Number(s):
[17075]
Open Access
Abstract: Recent studies apparently finding deleterious effects of radiation exposure on cataract formation in birds and voles living near Chernobyl represent a major challenge to current radiation protection regulations. This study conducted an integrated assessment of radiation exposure on cataractogenesis using the most advanced technologies available to assess the cataract status of lenses extracted from fish caught at both Chernobyl in Ukraine and Fukushima in Japan. It was hypothesised that these novel data would reveal positive correlations between radiation dose and early indicators of cataract formation.
The structure, function and optical properties of lenses were analysed from atomic to millimetre length scales. We measured the short-range order of the lens crystallin proteins using Small Angle X-Ray Scattering (SAXS) at both the SPring-8 and DIAMOND synchrotrons, the profile of the graded refractive index generated by these proteins, the epithelial cell density and organisation and finally the focal length of each lens.
The results showed no evidence of a difference between the focal length, the epithelial cell densities, the refractive indices, the interference functions and the short-range order of crystallin proteins (X-ray diffraction patterns) in lens from fish exposed to different radiation doses. It could be argued that animals in the natural environment which developed cataract would be more likely, for example, to suffer predation leading to survivor bias. But the cross-length scale study presented here, by evaluating small scale molecular and cellular changes in the lens (pre-cataract formation) significantly mitigates against this issue.
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Aug 2023
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[22909]
Open Access
Abstract: The discovery and development of new adhesive materials is critical for real-world applications of polymeric composite materials. Herein, we report the design and synthesis of a library of structurally related phase-separated supramolecular polyurethanes whose mechanical properties and adhesive characteristics can be enhanced through minor structural modifications of the polymer end-group. The interplay between phase separation of the hard domain polar end-groups and soft polybutadiene domains, coupled with tuneable self-assembly afforded by the polar end-groups, gives rise to a class of materials with tuneable mechanical properties. Exceptionally strong supramolecular adhesives and mechanically robust self-healing elastomers were identified. The mechanical properties were investigated through tensile testing. Finally, rheological analysis of the supramolecular materials was used to identify suitable healing and adhesive temperatures in addition to elucidate the supramolecular polyurethanes' thermal-responsive nature.
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Dec 2022
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I02-Macromolecular Crystallography
I03-Macromolecular Crystallography
I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[11316, 8458]
Open Access
Abstract: The mechanical properties of connective tissues are tailored to their specific function, and changes can lead to dysfunction and pathology. In most mammalian tissues the mechanical environment is governed by the micro- and nano-scale structure of collagen and its interaction with other tissue components, however these hierarchical properties remain poorly understood. In this study we use the human cornea as a model system to characterise and quantify the dominant deformation mechanisms of connective tissue in response to cyclic loads of physiological magnitude. Synchronised biomechanical testing, x-ray scattering and 3D digital image correlation revealed the presence of two dominant mechanisms: collagen fibril elongation due to a largely elastic, spring-like straightening of tropocollagen supramolecular twist, and a more viscous straightening of fibril crimp that gradually increased over successive loading cycles. The distinct mechanical properties of the two mechanisms suggest they have separate roles in vivo. The elastic, spring-like mechanism is fast-acting and likely responds to stresses associated with the cardiac cycle, while the more viscous crimp mechanism will respond to slower processes, such as postural stresses. It is anticipated that these findings will have broad applicability to understanding the normal and pathological functioning of other connective tissues such as skin and blood vessels that exhibit both helical structures and crimp.
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Jan 2022
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I22-Small angle scattering & Diffraction
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Andrew
Smith
,
S. G.
Alcock
,
L. S.
Davidson
,
J. H.
Emmins
,
J. C.
Hiller Bardsley
,
P.
Holloway
,
M.
Malfois
,
A. R.
Marshall
,
C. L.
Pizzey
,
S. E.
Rogers
,
O.
Shebanova
,
T.
Snow
,
J. P.
Sutter
,
E. P.
Williams
,
N. J.
Terrill
Open Access
Abstract: Beamline I22 at Diamond Light Source is dedicated to the study of soft-matter systems from both biological and materials science. The beamline can operate in the range 3.7 keV to 22 keV for transmission SAXS and 14 keV to 20 keV for microfocus SAXS with beam sizes of 240 µm × 60 µm [full width half-maximum (FWHM) horizontal (H) × vertical (V)] at the sample for the main beamline, and approximately 10 µm × 10 µm for the dedicated microfocusing platform. There is a versatile sample platform for accommodating a range of facilities and user-developed sample environments. The high brilliance of the insertion device source on I22 allows structural investigation of materials under extreme environments (for example, fluid flow at high pressures and temperatures). I22 provides reliable access to millisecond data acquisition timescales, essential to understanding kinetic processes such as protein folding or structural evolution in polymers and colloids.
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May 2021
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I22-Small angle scattering & Diffraction
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Brian R.
Pauw
,
Andrew
Smith
,
Tim
Snow
,
Olga
Shebanova
,
John P.
Sutter
,
Jan
Ilavsky
,
Daniel
Hermida-Merino
,
Glen J.
Smales
,
Nicholas J.
Terrill
,
Andreas F.
Thünemann
,
Wim
Bras
Open Access
Abstract: Ultra-SAXS can enhance the capabilities of existing synchrotron SAXS/WAXS beamlines. A compact ultra-SAXS module has been developed, which extends the measurable q-range with 0.0015 ≤ q (nm−1) ≤ 0.2, allowing structural dimensions in the range 30 ≤ D (nm) ≤ 4000 to be probed in addition to the range covered by a high-end SAXS/WAXS instrument. By shifting the module components in and out on their respective motor stages, SAXS/WAXS measurements can be easily and rapidly interleaved with USAXS measurements. The use of vertical crystal rotation axes (horizontal diffraction) greatly simplifies the construction, at minimal cost to efficiency. In this paper, the design considerations, realization and synchrotron findings are presented. Measurements of silica spheres, an alumina membrane, and a porous carbon catalyst are provided as application examples.
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May 2021
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[20249]
Open Access
Abstract: A detailed understanding of the local dynamics in ionic liquids remains an important aspect in the design of new ionic liquids as advanced functional fluids. Here, we use small-angle X-ray scattering and quasi-elastic neutron spectroscopy to investigate the local structure and dynamics in a model ionic liquid as a function of temperature and pressure, with a particular focus on state points (P,T) where the macroscopic dynamics, i.e., conductivity, is the same. Our results suggest that the initial step of ion transport is a confined diffusion process, on the nanosecond timescale, where the motion is restricted by a cage of nearest neighbors. This process is invariant considering timescale, geometry, and the participation ratio, at state points of constant conductivity, i.e., state points of isoconductivity. The connection to the nearest-neighbor structure is underlined by the invariance of the peak in the structure factor corresponding to nearest-neighbor correlations. At shorter timescales, picoseconds, two localized relaxation processes of the cation can be observed, which are not directly linked to ion transport. However, these processes also show invariance at isoconductivity. This points to that the overall energy landscape in ionic liquids responds in the same way to density changes and is mainly governed by the nearest-neighbor interactions.
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Mar 2021
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[27906]
Open Access
Abstract: Multicomponent hydrogels offer a tremendous opportunity to prepare useful and exciting materials that cannot be accessed using a single component. Here, we describe an unusual multi‐component low molecular weight gelling system that exhibits pH‐responsive behavior involving cooperative hydrogen bonding between the components, allowing it to maintain a gel phase across a wide pH range. Unlike traditional acid‐triggered gels, our system undergoes a change in the underlying molecular packing and maintains the β‐sheet structure both at acidic and basic pH. We further establish that autonomous programming between these two gel states is possible by an enzymatic reaction which allows us to prepare gels with improved mechanical properties.
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Feb 2021
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I15-Extreme Conditions
I22-Small angle scattering & Diffraction
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Danilo
Di Genova
,
Richard A.
Brooker
,
Heidy M.
Mader
,
James W. E.
Drewitt
,
Alessandro
Longo
,
Joachim
Deubener
,
Daniel R.
Neuville
,
Sara
Fanara
,
Olga
Shebanova
,
Simon
Anzellini
,
Fabio
Arzilli
,
Emily C.
Bamber
,
Louis
Hennet
,
Giuseppe
La Spina
,
Nobuyoshi
Miyajima
Diamond Proposal Number(s):
[17615, 20447]
Open Access
Abstract: Although gas exsolution is a major driving force behind explosive volcanic eruptions, viscosity is critical in controlling the escape of bubbles and switching between explosive and effusive behavior. Temperature and composition control melt viscosity, but crystallization above a critical volume (>30 volume %) can lock up the magma, triggering an explosion. Here, we present an alternative to this well-established paradigm by showing how an unexpectedly small volume of nano-sized crystals can cause a disproportionate increase in magma viscosity. Our in situ observations on a basaltic melt, rheological measurements in an analog system, and modeling demonstrate how just a few volume % of nanolites results in a marked increase in viscosity above the critical value needed for explosive fragmentation, even for a low-viscosity melt. Images of nanolites from low-viscosity explosive eruptions and an experimentally produced basaltic pumice show syn-eruptive growth, possibly nucleating a high bubble number density.
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Sep 2020
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[18402]
Open Access
Abstract: Understanding structure-property relationships is critical for the development of new drug delivery systems. This study investigates the properties of Pluronic smart hydrogel formulations for future use as injectable controlled drug carriers. The smart hydrogels promise to enhance patient compliance, decrease side effects and reduce dose and frequency. Pharmaceutically, these systems are attractive due to their unique sol-gel phase transition in the body, biocompatibility, safety and injectability as solutions before transforming into gel matrices at body temperature. We quantify the structural changes of F127 systems under controlled temperature after flow, as experienced during real bodily injection. Empirical formulae combining the coupled thermal and shear dependency are produced to aid future application of these systems. Induced structural transitions measured in-situ by small angle x-ray and neutron scattering reveal mixed oriented structures that can be exploited to tailor the drug release profile.
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Dec 2019
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