542 research outputs found
Quantum Magnetic Properties in Perovskite with Anderson Localized Artificial Spin-1/2
Quantum magnetic properties in a geometrically frustrated lattice of spin-1/2
magnet, such as quantum spin liquid or solid and the associated spin
fractionalization, are considered key in developing a new phase of matter. The
feasibility of observing the quantum magnetic properties, usually found in
geometrically frustrated lattice of spin-1/2 magnet, in a perovskite material
with controlled disorder is demonstrated. It is found that the controlled
chemical disorder, due to the chemical substitution of Ru ions by Co-ions, in a
simple perovskite CaRuO3 creates a random prototype configuration of artificial
spin-1/2 that forms dimer pairs between the nearest and further away ions. The
localization of the Co impurity in the Ru matrix is analyzed using the Anderson
localization formulation. The dimers of artificial spin-1/2, due to the
localization of Co impurities, exhibit singlet-to-triplet excitation at low
temperature without any ordered spin correlation. The localized gapped
excitation evolves into a gapless quasi-continuum as dimer pairs break and
create freely fluctuating fractionalized spins at high temperature. Together,
these properties hint at a new quantum magnetic state with strong resemblance
to the resonance valence bond system.Comment: 8 pages, 6 figure
Proteins in Ionic Liquids: Reactions, Applications and Futures
Biopolymer processing and handling is greatly facilitated by the use of ionic liquids, given the increased solubility, and in somecases, structural stability imparted to these molecules. Focussing on proteins, we highlight here not just the key drivers behind protein-ionic liquid interactions that facilitate these functionalities, but address relevant current and potential applications of protein-ionic liquid interactions, including areas of future interest
Dissecting the oxidative folding of circular cystine knot miniproteins
Cyclotides are plant proteins with exceptional stability owing to the presence of a cyclic backbone and three disulfide bonds arranged in a cystine knot motif. Accordingly, they have been proposed as templates to stabilize bioactive epitopes in drug-design applications. The two main subfamilies, referred to as the Möbius and bracelet cyclotides, require dramatically different in vitro folding conditions to achieve the native fold. To determine the underlying elements that influence cyclotide folding, we examined the in vitro folding of a suite of hybrid cyclotides based on combination of the Möbius cyclotide kalata B1 and the bracelet cyclotide cycloviolacin O1. The folding pathways of the two cyclotide subfamilies were found to be different and influenced by specific residues within intercysteine loops 2 and 6. Two changes in these loops, a substitution in loop 2 and an addition in loop 6, enabled the folding of a cycloviolacin O1 analogue under conditions in which folding does not occur in vitro for the native peptide. A key intermediate contains a native-like hairpin structure that appears to be a nucleation locus early in the folding process. Overall, these mechanistic findings on the folding of cyclotides are potentially valuable for the design of new drug leads. Copyright Mary Ann Liebert, Inc
Donor Availability in the Low Resource Environment: How Can we Deal with the Challenges:Meeting report of the session organised by the ISBT Working party Global Blood Safety Session on World Blood Donor Day during the ISBT in Focus online congress, June 14th, 2021
Donor Availability in the Low Resource Environment: How Can we Deal with the Challenges:Meeting report of the session organised by the ISBT Working party Global Blood Safety Session on World Blood Donor Day during the ISBT in Focus online congress, June 14th, 2021
Donor Availability in the Low Resource Environment: How Can we Deal with the Challenges:Meeting report of the session organised by the ISBT Working party Global Blood Safety Session on World Blood Donor Day during the ISBT in Focus online congress, June 14th, 2021
Donor Availability in the Low Resource Environment: How Can we Deal with the Challenges:Meeting report of the session organised by the ISBT Working party Global Blood Safety Session on World Blood Donor Day during the ISBT in Focus online congress, June 14th, 2021
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