High-pressure small-angle neutron scattering studies of glucose isomerase conformation in solution

Small-angle neutron scattering (SANS) of solutions of glucose/xylose isomerase fromStreptomyces rubiginosuswas measured as a function of pressure. It is shown that the structure of the enzyme in solution as seen by SANS is practically the same as that in the crystal and does not change with pressure up to 150 MPa. This reflects the unusually high structural stability of this material, which makes it extremely interesting to use as a secondary standard for pressure-dependent SANS experiments. This lack of pressure dependence of the SANS data also indicates that any possible change in hydration of the protein induced by pressure is not visible in the SANS curves. An appropriate correction procedure must be used for the SANS data in order to account for the distortion of the intensity curve due to hard-sphere and electrostatic interactions. After this correction, the isomerase can be readily used as a secondary standard for SANS measurements.

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A Study of Tio2 Aerogels Pore and Ramified Structure by Small-Angle Neutron Scattering

MRS Proceedings ◽

10.1557/proc-376-353 ◽

1994 ◽

Vol 376 ◽

Cited By ~ 1

Author(s):

Zhu Zhu ◽

Min Lin ◽

Geula Dagan ◽

Micha Tomkiewicz

Keyword(s):

Titanium Dioxide ◽

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Gas Adsorption ◽

Scattering Data ◽

Morphological Parameters ◽

Nitrogen Gas ◽

Light Density ◽

Sans Data

ABSTRACTThe microstructral characteristics of titanium dioxide aerogels were studied by Small Angle Neutron Scattering (SANS). A variety of models were used to extract the morphological parameters from the SANS data. The evaluation of scattering data was found to be consistent with nitrogen gas adsorption and TEM measurements of a model of aerogel consisting of a light density matrix in which meso- and macro-pores are embedded.

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Phase Separation In Blends of Polystyrene and Poly (P-METHYLSTYRENE) Using Thermal Analysis And Small-Angle Neutron Scattering

MRS Proceedings ◽

10.1557/proc-321-107 ◽

1993 ◽

Vol 321 ◽

Cited By ~ 1

Author(s):

A. Xenopoulos ◽

J. D. Londono ◽

G. D. Wígnall ◽

B. Wunderlich

Keyword(s):

Thermal Analysis ◽

Phase Separation ◽

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Small Difference ◽

Glass Transitions ◽

Scanning Calorimetry ◽

Reliable Detection ◽

Sans Data

ABSTRACTDifferential scanning calorimetry (DSC) was used to study blends of polystyrene (PS) and poly (p-Methylstyrene) (PpmS). The presence of two glass transitions on heating after quenching was interpreted as evidence of phase separation at the temperature of the liquid before quenching. The small difference between the glass transitions of the homopolymers in the PS/PpmS system of “13 K limits the reliable detection of double glass transitions for blends to concentrations between 30 and 70%. The results of the DSC technique are supported by comparison with small angle neutron scattering (SANS) data.

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A novel methodology to study nanoporous alumina by small-angle neutron scattering

Journal of Applied Crystallography ◽

10.1107/s160057671900726x ◽

2019 ◽

Vol 52 (4) ◽

pp. 745-754 ◽

Cited By ~ 2

Author(s):

Anastasia Christoulaki ◽

Alexis Chennevière ◽

Isabelle Grillo ◽

Lionel Porcar ◽

Emmanuelle Dubois ◽

...

Keyword(s):

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Condensed Matter ◽

Quantitative Information ◽

Sem Analysis ◽

Experimental Conditions ◽

Fitting Method ◽

Hexagonal Arrangement ◽

Sans Data

Nanoporous anodic aluminium oxide (AAO) membranes are promising host systems for confinement of condensed matter. Characterizing their structure and composition is thus of primary importance for studying the behavior of confined objects. Here a novel methodology to extract quantitative information on the structure and composition of well defined AAO membranes by combining small-angle neutron scattering (SANS) measurements and scanning electron microscopy (SEM) imaging is reported. In particular, (i) information about the pore hexagonal arrangement is extracted from SEM analysis, (ii) the best SANS experimental conditions to perform reliable measurements are determined and (iii) a detailed fitting method is proposed, in which the probed length in the fitting model is a critical parameter related to the longitudinal pore ordering. Finally, to validate this strategy, it is applied to characterize AAOs prepared under different conditions and it is shown that the experimental SANS data can be fully reproduced by a core/shell model, indicating the existence of a contaminated shell. This original approach, based on a detailed and complete description of the SANS data, can be applied to a variety of confining media and will allow the further investigation of condensed matter under confinement.

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Ultra-small-angle neutron scattering with azimuthal asymmetry

Journal of Applied Crystallography ◽

10.1107/s1600576716005586 ◽

2016 ◽

Vol 49 (3) ◽

pp. 934-943 ◽

Cited By ~ 13

Author(s):

X. Gu ◽

D. F. R. Mildner

Keyword(s):

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Incident Beam ◽

Bedding Plane ◽

Double Crystal ◽

Thin Sections ◽

Wide Range ◽

Sans Data ◽

Double Crystal Diffractometer

Small-angle neutron scattering (SANS) measurements from thin sections of rock samples such as shales demand as great a scattering vector range as possible because the pores cover a wide range of sizes. The limitation of the scattering vector range for pinhole SANS requires slit-smeared ultra-SANS (USANS) measurements that need to be converted to pinhole geometry. The desmearing algorithm is only successful for azimuthally symmetric data. Scattering from samples cut parallel to the plane of bedding is symmetric, exhibiting circular contours on a two-dimensional detector. Samples cut perpendicular to the bedding show elliptically dependent contours with the long axis corresponding to the normal to the bedding plane. A method is given for converting such asymmetric data collected on a double-crystal diffractometer for concatenation with the usual pinhole-geometry SANS data. The aspect ratio from the SANS data is used to modify the slit-smeared USANS data to produce quasi-symmetric contours. Rotation of the sample about the incident beam may result in symmetric data but cannot extract the same information as obtained from pinhole geometry.

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