Atomic distribution in zinc cadmium germanium phosphide (ZnxCd1-xGeP2) semiconductor alloys: phosphorus-31 and cadmium-113 magic-angle spinning, 31P spin-echo, and 31P-113Cd heteronuclear double quantum filtering MAS-NMR studies

1992 ◽  
Vol 96 (26) ◽  
pp. 11048-11054 ◽  
Author(s):  
Deanna Franke ◽  
Kesha Banks ◽  
Hellmut Eckert
Keyword(s):  
Spin Echo ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Double Quantum ◽  
Magic Angle ◽  
Semiconductor Alloys ◽  
Nmr Studies ◽  
Atomic Distribution ◽  
Zinc Cadmium ◽  
Angle Spinning

Continuous Flow Hyper-Polarized 129Xe-Mas Nmr Studies of Microporous Materials.

2003 ◽  
Vol 775 ◽  
Author(s):  
Andrei Nossov ◽  
Flavien Guenneau ◽  
Marie-Anne Springuel-Huet ◽  
Valérie Montouillout ◽  
Jean-Pierre Cognec ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
Original Design ◽  
Nmr Studies ◽  
Powder Samples ◽  
Angle Spinning

Summary:A Magic Angle Spinning (MAS) NMR probe has been designed allowing the in-situ measurements of NMR spectra of working catalyst. The probe was built following the original design of M. Hunger [Hunger, 1995 #2]. It allows the magic angle spinning of powder samples up to 3.5 kHz, under gas flowing conditions, and at temperatures up to 573K.

A multinuclear MAS NMR study of the short-range structure of fluorophosphate glass

1992 ◽  
Vol 7 (7) ◽  
pp. 1892-1899 ◽  
Author(s):  
R.K. Brow ◽  
Z.A. Osborne ◽  
R.J. Kirkpatrick
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectroscopic Studies ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
Nmr Studies ◽  
Nmr Study ◽  
Fluorophosphate Glass ◽  
Angle Spinning

We have examined the bonding arrangements in Na–P–O–F and Na–Al–P–O–F glasses using 19F, 27Al, and 31P solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. For the Al-free series of glasses, the 19F NMR spectra are dominated by peaks near +90 ppm, representative of F terminating P-chains. The formation of these bonds has little effect on the 31P chemical shifts, indicating that F preferentially replaces bridging oxygen on the phosphate tetrahedra, consistent with previous NMR studies of crystalline fluorophosphates and other spectroscopic studies of fluorophosphate glass. For the Na–Al–P–O–F glasses, 27Al NMR detects only octahedral Al-sites, the 19F NMR spectra include a second peak near −12 ppm due to F bonded to Al, and the 31P NMR spectra contain signals due to Q1-sites with one or more Al next-nearest neighbors. The relative intensity of the two 19F peaks correlates well with previous spectroscopic studies and shows that a greater fraction of F–P bonds forms when the base glass is remelted in NH4HF2.

Elucidation of correlated disorder in zeolite IM-18

2019 ◽  
Vol 75 (3) ◽  
pp. 333-342 ◽  
Author(s):  
Xiaoge Wang ◽  
Yihan Shen ◽  
Rongli Liu ◽  
Xiaolong Liu ◽  
Cong Lin ◽  
...  
Keyword(s):  
Single Crystal ◽  
Polycrystalline Sample ◽  
Simulation Method ◽  
Magic Angle Spinning ◽  
Two Dimensions ◽  
Mas Nmr ◽  
Double Quantum ◽  
Magic Angle ◽  
Disordered Structures ◽  
Angle Spinning

Classical crystallography is based on the translational periodicity of crystals and the analysis of discrete Bragg reflections. However, it is inadequate for determining disordered structures, of which the diffuse scattering is vital to evaluate the disorder level. The correlated disorder of IM-18 presents as zigzag chains arranged in translational periodicity and the double four-ring units randomly distributed along two dimensions. Supercell models regulated by multiple probabilities were systematically built to simulate the single-crystal and powder X-ray diffraction patterns in order to ascertain the specific disorder configuration in the single-crystal or polycrystalline samples of IM-18. The presence of defects in the polycrystalline sample was proved by combining 29Si magic angle spinning (MAS) NMR and 1H–1H double quantum MAS NMR spectra, and was quantitatively explored by the simulation method. The method could also elucidate other disordered structures in polycrystalline or single-crystal samples, despite the presence of defects or multidimensional disorder.

scholarly journals Resonance assignments and secondary structure analysis of dynein light chain 8 by magic-angle spinning NMR spectroscopy

2011 ◽  
Vol 89 (7) ◽  
pp. 909-918 ◽  
Author(s):  
Shangjin Sun ◽  
Andrew H. Butterworth ◽  
Sivakumar Paramasivam ◽  
Si Yan ◽  
Christine M. Lightcap ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Light Chain ◽  
Structural Information ◽  
Resonance Assignments ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
Dynein Light Chain ◽  
Nmr Studies ◽  
Angle Spinning

Dynein light chain LC8 is the smallest subunit of the dynein motor complex and has been shown to play important roles in both dynein-dependent and dynein-independent physiological functions via its interaction with a number of its binding partners. It has also been linked to pathogenesis including roles in viral infections and tumorigenesis. Structural information for LC8-target proteins is critical to understanding the underlying function of LC8 in these complexes. However, some LC8-target interactions are not amenable to structural characterization by conventional structural biology techniques owing to their large size, low solubility, and crystallization difficulties. Here, we report magic-angle spinning (MAS) NMR studies of the homodimeric apo-LC8 protein as a first effort in addressing more complex, multi-partner, LC8-based protein assemblies. We have established site-specific backbone and side-chain resonance assignments for the majority of the residues of LC8, and show TALOS+-predicted torsion angles ϕ and ψ in close agreement with most residues in the published LC8 crystal structure. Data obtained through these studies will provide the first step toward using MAS NMR to examine the LC8 structure, which will eventually be used to investigate protein–protein interactions in larger systems that cannot be determined by conventional structural studies.

scholarly journals Combination of solid state NMR and DFT calculation to elucidate the state of sodium in hard carbon electrodes

2016 ◽  
Vol 4 (34) ◽  
pp. 13183-13193 ◽  
Author(s):  
Ryohei Morita ◽  
Kazuma Gotoh ◽  
Mika Fukunishi ◽  
Kei Kubota ◽  
Shinichi Komaba ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Dft Calculation ◽  
Magic Angle Spinning ◽  
The State ◽  
Mas Nmr ◽  
Magic Angle ◽  
Multiple Quantum ◽  
Hard Carbon ◽  
Angle Spinning

We examined the state of sodium electrochemically inserted in HC prepared at 700–2000 °C using solid state Na magic angle spinning (MAS) NMR and multiple quantum (MQ) MAS NMR.

scholarly journals Sampling Method Affects HR-MAS NMR Spectra of Healthy Caprine Brain Biopsies

Metabolites ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 38
Author(s):  
Annakatrin Häni ◽  
Gaëlle Diserens ◽  
Anna Oevermann ◽  
Peter Vermathen ◽  
Christina Precht
Keyword(s):  
Nmr Spectroscopy ◽  
Sampling Method ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
1H Nuclear Magnetic Resonance ◽  
Rapid Changes ◽  
Tissue Degradation ◽  
Angle Spinning

The metabolic profiling of tissue biopsies using high-resolution–magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy may be influenced by experimental factors such as the sampling method. Therefore, we compared the effects of two different sampling methods on the metabolome of brain tissue obtained from the brainstem and thalamus of healthy goats by 1H HR-MAS NMR spectroscopy—in vivo-harvested biopsy by a minimally invasive stereotactic approach compared with postmortem-harvested sample by dissection with a scalpel. Lactate and creatine were elevated, and choline-containing compounds were altered in the postmortem compared to the in vivo-harvested samples, demonstrating rapid changes most likely due to sample ischemia. In addition, in the brainstem samples acetate and inositols, and in the thalamus samples ƴ-aminobutyric acid, were relatively increased postmortem, demonstrating regional differences in tissue degradation. In conclusion, in vivo-harvested brain biopsies show different metabolic alterations compared to postmortem-harvested samples, reflecting less tissue degradation. Sampling method and brain region should be taken into account in the analysis of metabolic profiles. To be as close as possible to the actual situation in the living individual, it is desirable to use brain samples obtained by stereotactic biopsy whenever possible.

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