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A surprisingly strong spin rate dependence of (15)N and (13)C NMR T(1) times in magic angle spinning experiments on solid peptides is demonstrated. Using a variety of isotopomers, the phenomenon is shown to be the result of chemical shift anisotropy-mediated spin diffusion. This effect has the potential to be used to detect long-range distance constraints in macromolecular systems.
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http://dx.doi.org/10.1021/ja106730p | DOI Listing |
Phys Rev Lett
August 2025
McMaster University, Department of Physics and Astronomy, Hamilton, Ontario L8S 4M1, Canada.
Magnetic heat capacity measurements of a high-quality single crystal of the dipole-octupole pyrochlore Ce_{2}Hf_{2}O_{7} down to a temperature of T=0.02 K are reported. These show a two-peaked structure, with a Schottky-like peak at T_{1}∼0.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
September 2025
Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States.
Density functional theory (DFT) calculations are employed to investigate the formation energies, charge redistribution, and binding energies of iron-oxygen divacancies in magnetite (FeO) and hematite (FeO). For magnetite, we focus on the low-temperature phase to explore variations with local environments. Building on previous DFT calculations of the variations in formation energies for oxygen vacancies with local charge and spin order in magnetite, we extend this analysis to include octahedral iron vacancies before analyzing the iron-oxygen divacancies.
View Article and Find Full Text PDFChem Sci
September 2025
College of Chemistry and Materials Engineering, Wenzhou University Wenzhou Zhejiang 325035 P. R. China
Sodium-ion batteries (SIBs) are promising alternatives to lithium-ion batteries (LIBs) owing to abundant resources and cost-effectiveness. However, cathode materials face persistent challenges in structural stability, ion kinetics, and cycle life. This review highlights the transformative potential of high-entropy (HE) strategies that leveraging multi-principal element synergies to address these limitations entropy-driven mechanisms.
View Article and Find Full Text PDFOrg Biomol Chem
September 2025
Glycosystems Laboratory, Instituto de Investigaciones Químicas (IIQ), Centro de Investigaciones Científicas Isla de La Cartuja, CSIC and Universidad de Sevilla, 41092 Sevilla, Spain.
In this paper, we present the NMR analysis of multivalent compounds displaying chondroitin sulfate E (CS-E) disaccharide ligands and their interaction with langerin. The disaccharides correspond to the two alternative sequences of CS-E: GlcA-GalNAc and GalNAc-GlcA. Firstly, we studied the conformation of the two corresponding series of glycodendrimers free in solution and in the presence of langerin.
View Article and Find Full Text PDFMagn Reson Med
September 2025
Laboratorio de Procesado de Imagen (LPI), Universidad de Valladolid, Valladolid, Spain.
Purpose: (a) To design a methodology for drawing random samples of any Ensemble Average Propagator (EAP) (b) to modify the KomaMRI simulator to accommodate them as realistic spin movements to simulate diffusion MRI (dMRI) and (c) to compare these simulations with those based on the Diffusion Tensor (DT) model.
Theory And Methods: The rejection method is used for random sampling of EAPs: starting from a probability law that is easily sampled, and whose density function wraps the target EAP, samples are accepted when they lie inside the targeted region. This is used to sample the EAP as described by Mean Apparent Propagator MRI (MAP-MRI) and in Spherical Convolution (SC) based on Spherical Harmonics (SH).