cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1510620
title: Calcium and pH induced changes in silk solutions

description: Spider silks are known to have outstanding mechanical properties yet there is still much unknown about how the initial structure, storage and transformation of the silk proteins influence these properties. We have recently characterised the intial shape and size of native silkworm and four principal spider silk proteins in solution, using small angle scattering. In addition to flow, it is known that the concentration of metal ions and pH varies as the silk proteins are processed by the silkworm or spider to form the silk fibre. We wish to examine how these chemical changes influence the size, shape and flexibility of native silk proteins in solution. By comparing silkworm silk with the 4 principal spider silk proteins we will show whether all the silks may have a similar processing route and thus will be directly relevant to our understanding of these high performance natural fibres.
DOI: 10.5286/isis.e.rb1510633
title: Monitoring Packing Changes in Magnetic Halogenated Phthalocyanine Molecules

description: The way that small molecules pack together can have substantial ramifications on the observed physical properties, reactivity, and device characteristics, even if the molecule being packed is structurally identical. This is true in a number of fields of organic chemistry, including pharmaceuticals and organic semiconductors, the latter of which is the subject of this proposal. We aim to demonstrate the ability of the pair distribution function to identify details of molecular packing and short-range magnetic interactions in some manganese phthalocyanine molecules.
DOI: 10.5286/isis.e.rb1520236
title: Exploring nanoscale phase separation in alpha-NaMnO2 and CuMnO2 2D frustrated antiferromagnets  by  atomic PDF analysis

description: Recently, our combined diffraction and NMR experiments have shown that alpha-NaMnO2, an antiferromagnet with two-dimensional triangular stacked topology, is a striking example of an insulating system where the spin,  degree of freedom induces multiple competing phases. In order to shed light in the role of geometric spin frustration, studies of isostructural compounds by total scattering approaches are highly sought. For this reason we request 5-days of beam time on GEM to raise evidence on the evolution of the near-equivalent structural phases of alpha-NaMnO2 against the case of the isostructural, more homogeneous CuMnO2. By analyzing their atomic pair distribution function (PDF) data, we aim to learn how the competition evolves into locally broken symmetry states when the critical region is approached and the transformation from the disordered to the Néel ordered states takes place.
DOI: 10.5286/isis.e.rb1520333
title: NR Study of Selective Binding of a-Helix Antimicrobial Peptides onto Bacterial and Red Blood Cells Membrane Mimics Using Floating Bilayers

description: In this work we will explore how to use PolRef to study the binding of our rationally designed peptide amphiphiles onto floating lipid bilayers mimicking G- bacterial and red blood cell membranes. To help gain insight into the selective binding processes, we will select 2 representative peptides at 2 concentrations (below and above their MICs to typical bacteria) under 3 contrasts (d- and h-lipids and H2O/D2O), requesting 6 days of PolRef beam time. This work will provide valuable molecular insight of peptide selectivity to different membranes under different conditions.
DOI: 10.5286/isis.e.rb1569002
title: Simultaneous SANS and modulated SESANS to resolve growth of surfactant-templated silica materials
DOI: 10.5286/isis.e.rb1610076
title: Investigating the diffusion of C6 cyclic and aromatic hydrocarbons in Pt/MCM-41

description: Diffusion of a range of cyclic hydrocarbons relevant to the nylon production process will be measured in the potential  catalyst Pt/MCM-41 in the context of the benzene hydrogenation reaction. Diffusion will be measured at a number of temperatures in order to gauge the effect of pi-bonding and aromaticity (and thus intermolecular interactions) on the mobility of these molecules. This work is part of a wider project where kinetics of the benzene hydrogenation in this catalyst reaction were successfully measured using neutron total scattering, concluding that mass transport played a crucial role in reaction progress. We aim to directly quantify this mass transport and factors affecting it. This work is also of a more general interest for considering the effect of liquid confinement in porous solids and factors dictating this effect.
DOI: 10.5286/isis.e.rb1610130
title: Skyrmion phase dynamics in the beta-Mn-type system Co8Zn8Mn4

description: Skyrmions are topological objects which have been shown to exist in the spin textures of a range of magnetic materials. As we have recently demonstrated in our transverse field ?muSR work on these systems, mu?SR is a promising method for exploring the physics of skyrmion lattices (SLs). Here we propose to extend these investigations in two ways: (i) to the study of slow dynamics via the use of longitudinal field ?muSR, and (ii) to investigate a new class of skyrmion system - the beta-Mn-type magnet Co8Zn8Mn4
DOI: 10.5286/isis.e.rb1610149
title: Interaction of Low Density Lipoproteins (LDL) with Model Mammalian Cell Membranes

description: Atherosclerosis and subsequent clinical complication is one of the biggest killers in the western world, with a death toll reaching 16.7 million deaths per year. Although many risk factors have been identified, it is well known that various lipoprotein particles in the blood play an important role in the development and rupture of atherosclerotic plaques. Upon adsorption to the cell membrane LDL is thought to exchange both lipids and cholesterol with the blood vessel wall. The unloading of LDL cholesterol cargo may initiate atherosclerotic plaque development. In this experiment we aim to study firstly the adsorption of LDL to a supported lipid bilayer as a function of bilayer charge (PC:PS) ratios. Secondly, through the use of fully deuterated lipid molecules (DMPC, DMPS and cholesterol) we aim to study exchange of the LDL components with the bilayer.
DOI: 10.5286/isis.e.rb1610235
title: Electron Correlation in Expanded Metal Amines: Overcoming Sample Environment Difficulties with High Momentum Muons

description: We have recently completed 4 days on EMU investigating the evolution of local magnetic states in the expanded metal, lithium amine systems. Our results are promising. However, the study of these mixed amine systems was hindered by the necessity for in situ preparation. The difficulties encountered can be avoided by the use of high momentum muons on ARGUS allowing for off-site preparation of samples in bespoke quartz containers. We aim to probe the evolution of local magnetic states in Li(MeNH2)4 and consolidate indications that Li(NH3)2(MeNH2)2 has distinctly different magnetic character to the parent amines.
DOI: 10.5286/isis.e.rb1610476
title: Inelastic neutron scattering investigations to study Ru-trimer and molecular orbital excitations in Ba4Ru3O10

description: The orthorhombic compound Ba4Ru3O10 having Ru3O12 timers coupled via corner-shared oxygens in the crystal structure exhibits very interesting magnetic and transport properties. The susceptibility exhibits a broad maximum near 180K, indicating low-dimensional magnetism, followed by the AFM ordering at 105K. The neutron diffraction study shows that one of the Ru sites, Ru(2) site, orders magnetically, while another Ru site, Ru(1) site, at the centre of a trimer bears no ordered magnetic moment. This behaviour is discussed in the framework of the strong spin-orbit coupling attributed to Ru4+ (4d4 S=1) ions. The ground state of Ru(1) site is proposed to be J=0 with J=1 an excited state. It would be interesting to study the magnetic excitations, spin wave, trimers and molecular orbital excitations, using inelastic neutron scattering to understand the nature of the magnetic interactions.
DOI: 10.5286/isis.e.rb1620242
title: INS of Ln(trensal-thiphene)

description: We have synthesised the series of lanthanide complexes Ln(trensal-thiophene), where Ln = Er, Dy, Yb and H3trensal = 2,2,2-tris(salicylideneimino)trimethylamine. These complexes are functionalised with thiphene groups which make them suitable for graftiong on gold surfaces by specific S - Au interactions. We would like to study the INS spectra of these complexes, in concern with other spectroscopic techniques, to ununmiguously determine their energy spectrum. This information will help us rationalise the static and dynamic magnetic properties of these complexes.
DOI: 10.5286/isis.e.rb1620246
title: Understanding elevated temperature and creep properties of a novel maraging steel

description: Producing a steel alloy that has both high and low temperature capabilities is non-trivial. However, recently a novel maraging steel has been developed that has shown excellent high and low temperature properties. In previous work we have shown how the thermomechanical processing route influences the mechanical properties, and models have been developed to understand the microstructural changes and mechanical behaviour. However, the creep behaviour has proved more difficult to understand. The problem in understanding creep is that accurate quantification of the microstructural changes is difficult and quantification is not possible by other methods. Hence, we want to use SANS to characterise precipitation and void formation to be able to understand and model creep and elevated temperature properties of this alloy.
DOI: 10.5286/isis.e.rb1620409
title: Are ice particles in the laboratory "good" analogues for collision studies of planet-formation processes?

description: With the discovery of almost 3000 exo-planets it is clear that planet formation is a by-product of star formation, yet in the micron  cm size range, where relative velocities are just a few cm s-1, we still do not know how particles stick forming larger boulders until gravitational interactions lead to planet formation. It is postulated that icy grains are the key to this process, but this can only be determined empirically, and much uncertainty remains as to whether the icy particles used in collision experiments really resemble those in planet-forming regions. Here we exploit NIMRODs fast acquisition times and wide Q-range to concurrently characterise the particle size, shape, and ice-phase distributions of a range of icy particle samples prepared by different methods, to feed back to our understanding in planet forming models.
DOI: 10.5286/isis.e.rb1620462
title: Exploring the potential of energy-dependent neutron imaging

description: We would like to explore the potential of energy-dependent neutron imaging, in view of the future Bragg edge transmission analysis options on IMAT and LARMOR. The experiments will use the latest neutron sensitive microchannel plate (MCP) detection system, characterize its performance on a TS-2 neutron beam and produce data sets for developing data processing and corrections procedures for energy-resolved neutron radiography and tomography. Data sets will be collected on a range of standard samples and engineering alloys of varying composition and geometry, to verify the usefulness of neutron imaging for phase, grain and strain mapping in engineering alloys. We ask for a total of 12 days on LARMOR.
DOI: 10.5286/isis.e.rb1670556
title: mSR investigation of atomic structure and photocatalytic properties of defects in rutile TiO2 crystal
DOI: 10.5286/isis.e.rb1700055
title: Rotor dynamics in an organic quantum spin liquid candidate

description: Mimicking the motion of functional biological systems has become possible as a result of sophisticated modern nanotechnology and materials science.In the layered organic quantum spin liquid candidate, (EDT-TTF-CONH2)2+[BABCO]-, the Brownian motion of the molecular rotor BABCO- layers was detected by the virtue of the measurement of T1 using 1H NMR. As the conducting layer of (EDT-TTF-CONH2)2+ is coupled with the rotors, a braked, damped motion is found in the rotor layer. However, the NMR data is limited to the high-temperature regime.  Thus we propose zero-field and longitudinal field Muon Spin Rotation measurements from 2 K to 300 K to investigate the rotor dynamics of the BABCO- layers.This experiment would complete our low-temperature MuSR data of the quantum spin liquid state in this compound, and would help us to better understand the role of disorder in the QSL state.
DOI: 10.5286/isis.e.rb1700058
title: The structure of methane water fluid mixtures at high pressure

description: We have recently discovered that above 2 GPa in the liquid/fluid forms water and methanebecome miscible in proportions up to 33 mole% of methane. This proposal is for time to study thestructure of this remarkable liquid/fluid.
DOI: 10.5286/isis.e.rb1700066
title: Structure of yeast lipid monolayers and the effects of Amphotericin B

description: We have recently developed methods for the extraction, separation and analysis of lipids from yeast cell cultures as physiologically realistic targets for membrane binding drugs such as the antifungal agent Amphotericin B. Our previous results using NR on supported bilayers have shown that the structural consequences of Amphotericin B intricately depend on the membrane lipid composition, in particular of polyunsaturated lipids. In this joint Diamond-ISIS proposal we aim to use a combination of NR, XRR and GIXD to obtain a more detailed picture of yeast lipid structures in monolayers at the air-water interface, in particular the headgroup conformation and the degree of chain ordering, and how AmB changes these. There results will enable a better understanding of the effects of AMB in our yeast lipid membranes and those previously published on model lipid monolayers.
DOI: 10.5286/isis.e.rb1700074
title: Interfacial structures and competitive adsorption of amphiphilic polymers with surfactants at the air-water interface

description: Foam stability, appearance and functionality is governed by the thin liquid films between foam bubbles. These films are stabilised by surface active molecules (surfactants and polymers). The structures of these mixtures at the interface is therefore of crucial importance. We propose to study mixed polymer/surfactant systems relevant to cleaning products, in particular the influence of the polymer molecular architecture and charge on the interfacial structures. The ultimate aim is to establish a link between the interfacial and bulk structures, and their potential industrial applications regarding their foaming and cleaning properties.
DOI: 10.5286/isis.e.rb1710294
title: Adsorption of bioengineered antibodies at the oil/water interface

description: Following our previous study of adsorption of Fc, Fab and the constituent mAb COE-3,  we continue to explore how two bioengineered mAbs adsorb at the oil/water interface by neutron reflection. Inter is preferred because we have built technical capability on this instrument. COE-7 and COE-8 have enlarged Fab and Fc domains and reduced globular stability. Our specific aims are to (a) determine the actual thickness and volume fraction of and (b) the effect of pH on the interfacial distribution. The results will enable us to compare their extent of distributions into the oil region with other globular proteins at the interface. We can then answer if all the globular proteins unfold and produce characteristic segment distributions into the oil region.
DOI: 10.5286/isis.e.rb1710437
title: Examining Hydration Dynamics and the Glass Transition Behaviour of Keratin Fibres using QENS

description: Proteinwater interactions establish and shape the thermodynamic landscape that governs the folding, structure, stability, mechanics and activity of proteins, and thus performance of protein based materials such as skin and hair. In tissue or cellular based protein material systems such as human hair the mechanical and physical performance of these materials in humid environments is very complex and is poorly understood.In this study a series of keratin based fibres, including hairs of different ethinicitiies, will be studied at different humidities and temperatures using neutron scattering. This work will allow us to better understand the way water diffuses in these complex materials at different temperatures and humidiies. This improved understanding of the hydration behaviour of hair may facilitate  the development of improved products for hair care.
DOI: 10.5286/isis.e.rb1510000
title: High Pressure Neutron Diffraction of Croconic Acid

description: Croconic acid (Cacid) possesses a well-defined hysteresis in polarization at room temp and the highest spontaneous polarization observed in organic ferroelectrics to date. The high polarity reversal is thought to be related to the 2 crystallographically independent hydrogen bonding networks.Recently, we performed investigations on Cacid under high-pressure to determine if the pressure induced shortening of the O-O bond would affect the dynamic proton behaviour. The results indicate pressure-induced polymerization near 5.5 GPa.Between 5-10 GPa a gradual diffuse change traditionally associated with a ferroelectric-paraelectric phase transition was observed in the dielectric constant. Upon decompression, the characteristics of the high-pressure polymorph are retained. A neutron study of Cacid using PEARL to investigate the structural changes in the hydrogen bonding network seems warranted.
DOI: 10.5286/isis.e.rb1510054
title: DRUG EFFECTS ON INTRACELLULAR WATER DYNAMICS: CISPLATIN IN HUMAN CANCER CELLS

description: Water dynamics plays a vital role in biochemical processes in a living organism. Intracellular water structure and dynamics are known to be changed by the presence of biomolecules or extrinsic entities (e.g. drugs), while in turn water is prone to disturb the conformation and function of biomolecules. Disruption of the coherent structure of cellular water by even very subtle stimuli is expected to have a significant cost at the functional level and may even induce pathology.The present study aims at extending this concept to the activity of pharmacological agents. Upon a successful exploratory experiment (OSIRIS/RB1400034), the QENS technique will be used to probe the effect of an anticancer drug (cisplatin) on water dynamics in human cancer cells. This is an innovative way of tackling the drug´s pharmacodynamics leading to an improved understanding of its in vivo mode of action.
DOI: 10.5286/isis.e.rb1510076
title: Interaction between slow dynamics of nuclear and magnetic domains in relaxor magnet LuFeCoO4

description: Neutron experiment is carried out on relaxor magnet LuFeCoO4 to study the coupling between the slow dynamics of the dielectric and magnetic properties. At 190 K, the nuclear and magnetic diffuse intensities change simultaneously. Furthermore, the magnetic correlation length along (1,1,0) direction coincides the size of the polar nanoregions estimated from nuclear diffuse scattering in the c-plane. Since the same domain provides both electric and magnetic properties, strong coupling between the two properties through the domain size is expected.
DOI: 10.5286/isis.e.rb1510236
title: Controlling the length of polymeric supramolecular nanotubes

description: The self-assembly of (cyclic peptide)-polymer conjugates provide a versatile and functional platform for the precise design of polymeric supramolecular nanotubes. Moving the platform into aqueous media has been a recent accomplishment that has unlocked many exciting applications; but to complement these advances, we require better control over the structure (in particular, the length) of the nanotube. Here we propose to employ the use of electrostatic interactions to control the thermodynamic product, providing precise control over nanotube lengths and access to more complex nanostructures, such as barcoded and end-functionalised nanotubes.
DOI: 10.5286/isis.e.rb1510392
title: Total scattering study of the II to I phase transition in pyridine

description: Atomistic characterisation of phase transitions in organic materials is important because of the role played by polymorphism in pharmaceuticals and agochemicals. Conventional crystallographic experiments yield an average view of the crystalline state, a substantial approximation in the context of dynamic phenomena like phase transitions. For example there is no information in an ¿average¿ crystal structure on defects which play a crucial role in reconstructive phase transitions.  We will study an unusual transition in pyridine which is only observed if the sample is deuterated. Pyridine-d5 forms a complex Z¿=4 phase on cooling from the liquid.  This phase can be cooled to 2K, where it is metastable. On warming to 170 K it transforms to a Z¿=1 phase, which transforms back to the Z¿=4 phase at 215 K. Total scattering analysis will explore the role of stacking defects in these transitions.
DOI: 10.5286/isis.e.rb1510395
title: flipping and desorption energetics of cholesterol in lipid-raft environments

description: Cholesterol levels in membranes of cellular organelles varies immensely. For example, cholesterol in the plasma membrane (PM) is 35¿45% of the lipid content , while in the endoplasmic reticulum, the site of cholesterol synthesis, it is only 1¿10%. Further, the distribution of cholesterol across the PM is thought to be asymmetric since its outer leaflet is enriched in saturated lipids. These lipids are preferred by cholesterol due to better packing and water-shileding properties compared to unsaturated lipids. Here we propose to investigate the flipping and desorption/absorption behavior of cholesterol in supported flat membranes that mimic the outer PM using time resolved neutron reflectivity. MD simulations suggest that cholesterol flip-flop in these membranes is in the tens of minutes while in purely unsaturated or saturated membranes it is in the millisecond range.
DOI: 10.5286/isis.e.rb1510463
title: Quantification of Residual Stresses in Ferritic Steels using Low-Transformation-Temperature and Conventional Ferritic Welding Consumables

description: F22 steel is widely used in subsea oil transfer components to control flow and defend against well pressure increases. As easily attainable oil deposits have reduced, it is vital to extract oil from deeper subsea reservoirs. This pushes current material to withstand greater pressures, temperatures and corrosion. Hence, requiring the design of new materials to resist greater degradation. A novel hydrogen-resistant HT10 steel was designed to replace F22, although many performance aspects need to be assessed and compared. Welding residual stresses is one critical area, as these stresses are additive with service stress and can cause cracking in welds. Recently, we studied the development of residual stresses in HT10 steel welds using different filler materials. This proposal aims to quantify residual stresses in F22 welds with identical filler materials and provide comparisons with HT10.
DOI: 10.5286/isis.e.rb1510539
title: A Single Crystal study of the Helical and Skyrmion Textures in a Chiral Magnetic system.

description: Cu2OSeO3 belongs to a family of magnetic crystals that displays unique properties of a whirlpool like vortex of magnetic moments (skyrmions) in a small range of temperature and applied magnetic field. Skyrmions are particle-like nanometer sized spin textures observed only in chiral magnetic systems. These have promising uses in the development of new low-powered computing devices. The understanding of the formation of these vortices is important in the development of room temperature operational devices. This system also displays interesting helical and conical magnetic structures which along with the skyrmions form a stable lattice that can be observed by neutron diffraction. We aim to measure for the first time the properties of the system with a technique that allows us to study the crystallographic and magnetic structure as a function of both temperature and applied magnetic field.