High-sensitivity (27)Al nuclear magnetic resonance (NMR) measurements of aluminum metal under hydrostatic pressure of up to 10.1 GPa reveal an unexpected negative curvature in the pressure dependence of the electronic density of states measured through shift and relaxation, which violates free electron behavior. A careful analysis of the Fermiology of aluminum shows that pressure induces an electronic topological transition (Lifshitz transition) that is responsible for the measured change in the density of states. The experiments also reveal a sudden increase in the NMR linewidth above 4.2 GPa from quadrupole interaction, which is not in agreement with the metal's cubic symmetry.
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http://dx.doi.org/10.1088/0953-8984/26/1/015501 | DOI Listing |
Rev Cardiovasc Med
January 2025
Section of Cardiovascular Imaging, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH 44195, USA.
With the aging of the general population and the rise in surgical and transcatheter aortic valve replacement, there will be an increase in the prevalence of prosthetic aortic valves. Patients with prosthetic aortic valves can develop a wide range of unique pathologies compared to the general population. Accurate diagnosis is necessary in this population to generate a comprehensive treatment plan.
View Article and Find Full Text PDFIndiana Univ J Undergrad Res
June 2024
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine.
Angiomotins (Amots) are a family of adaptor proteins with important roles in cell growth, migration, and proliferation. The Amot coiled-coil homology (ACCH) domain has a high affinity for non-phosphorylated and mono-phosphorylated phosphatidylinositol which provides specificity in the membrane association. The membrane specificity is linked with targeting and recycling of the membrane protein to maintain normal cell phenotypes and function.
View Article and Find Full Text PDFACS Omega
January 2025
Green Chemical Reaction Engineering, Engineering and Technology Institute Groningen, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Pyrolysis liquids from lignocellulosic biomass have the potential to be used as a feed for aromatics such as benzene, toluene, and xylenes (BTX) using catalytic upgrading with zeolites. We here report an experimental study on the conversion of various pyrolysis oil fractions to determine the most suitable one for BTX synthesis. For this purpose, the pyrolysis liquid was fractionated using several extraction/distillation steps to give four fractions with different chemical compositions.
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January 2025
Applied Chemistry and Environment Laboratory, Applied Bioorganic Chemistry Team, Faculty of Science, Ibn Zohr University, Agadir 80000, Morocco.
The goal of this study was to synthesize and evaluate new antimicrobial compounds. We specifically focused on the development of 2,5-disubstituted tetrazole derivatives containing the O-methyl-2,3-O-isopropylidene-(D)-ribofuranoside groups through N-alkylation reactions. The synthesized compounds were characterized using H and C nuclear magnetic resonance (NMR) spectroscopy.
View Article and Find Full Text PDFACS Omega
January 2025
Science Division, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates.
Determining the structure of sitagliptin is crucial for ensuring its effectiveness and safety as a DPP-4 inhibitor used to treat type 2 diabetes. Accurate structure determination is vital for both drug development and maintaining quality control in manufacturing. This study integrates the advanced techniques of solid-state nuclear magnetic resonance (NMR) spectroscopy, three-dimensional (3D) electron diffraction, and density functional theory (DFT) calculations to investigate the structural intricacies of sitagliptin.
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