258 research outputs found
Spin correlations and Dzyaloshinskii-Moriya interaction in CsCuCl
We report on electron spin resonance (ESR) studies of the spin relaxation in
CsCuCl. The main source of the ESR linewidth at temperatures K is attributed to the uniform Dzyaloshinskii-Moriya interaction. The
vector components of the Dzyaloshinskii-Moriya interaction are determined from
the angular dependence of the ESR spectra using a high-temperature
approximation. Both the angular and temperature dependence of the ESR linewidth
have been analyzed using a self-consistent quantum-mechanical approach. In
addition analytical expressions based on a quasi-classical picture for spin
fluctuations are derived, which show good agreement with the quantum-approach
for temperatures K. A small modulation of the
ESR linewidth observed in the -plane is attributed to the anisotropic
Zeeman interaction, which reflects the two magnetically nonequivalent Cu
positions
RNA oligomers at atomic resolution containing 1âmethylpseudouridine, an essential building block of mRNA vaccines
All widely used mRNA vaccines against COVIDâ19 contain in their sequence 1âmethylpseudouridine (m1Κ) instead of uridine. In this publication, we report two high resolution crystal structures (at up to 1.01 and 1.32â
Ă
, respectively) of one such doubleâstranded 12âmer RNA sequence crystallized in two crystal forms. The structures are compared with similar structures which do not contain this modification. Additionally, the Xâray structure of 1âmethylâpseudouridine itself was determined
Sound-propagation gap in fluid mixtures
We discuss the behavior of the extended sound modes of a dense binary
hard-sphere mixture. In a dense simple hard-sphere fluid the Enskog theory
predicts a gap in the sound propagation at large wave vectors. In a binary
mixture the gap is only present for low concentrations of one of the two
species. At intermediate concentrations sound modes are always propagating.
This behavior is not affected by the mass difference of the two species, but it
only depends on the packing fractions. The gap is absent when the packing
fractions are comparable and the mixture structurally resembles a metallic
glass.Comment: Published; withdrawn since ordering in archive gives misleading
impression of new publicatio
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