251 research outputs found
A Two-stage Deep Learning Receiver for High Throughput Power Efficient LEO Satellite System with Varied Operation Status
Release of Corrosive Species above the Grate in a Waste Boiler and the Implication for Improved Electrical Efficiency
A Helium-Surface Interaction Potential of BiTe(111) from Ultrahigh-Resolution Spin-Echo Measurements
We have determined an atom-surface interaction potential for the
HeBiTe(111) system by analysing ultrahigh resolution measurements of
selective adsorption resonances. The experimental measurements were obtained
using He spin-echo spectrometry. Following an initial free-particle model
analysis, we use elastic close-coupling calculations to obtain a
three-dimensional potential. The three-dimensional potential is then further
refined based on the experimental data set, giving rise to an optimised
potential which fully reproduces the experimental data. Based on this analysis,
the HeBiTe(111) interaction potential can be described by a
corrugated Morse potential with a well depth , a
stiffness and a surface electronic
corrugation of % of the lattice constant. The improved
uncertainties of the atom-surface interaction potential should also enable the
use in inelastic close-coupled calculations in order to eventually study the
temperature dependence and the line width of selective adsorption resonances
Spatially resolved spectroscopic differentiation of hydrophilic and hydrophobic domains on individual insulin amyloid fibrils
The formation of insoluble β-sheet-rich protein structures known as amyloid fibrils is associated with numerous neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease. A detailed understanding of the molecular structure of the fibril surface is of interest as the first contact with the physiological environment in vivo and plays a decisive role in biological activity and associated toxicity. Recent studies reveal that the inherent sensitivity and specificity of tip-enhanced Raman scattering (TERS) renders this technique a compelling method for fibril surface analysis at the single-particle level. Here, the reproducibility of TERS is demonstrated, indicating its relevance for detecting molecular variations. Consequently, individual fibrils are systematically investigated at nanometer spatial resolution. Spectral parameters were obtained by band-fitting, particularly focusing on the identification of the secondary structure via the amide III band and the differentiation of hydrophobic and hydrophilic domains on the surface. In addition multivariate data analysis, specifically the N-FINDR procedure, was employed to generate structure-specific maps. The ability of TERS to localize specific structural domains on fibril surfaces shows promise to the development of new fibril dissection strategies and can be generally applied to any (bio)chemical surface when structural variations at the nanometer level are of interest
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