Heating caused by radiofrequency irradiation and sample rotation in13C magic angle spinning NMR studies of lipid membranes

2004 ◽  
Vol 42 (10) ◽  
pp. 875-881 ◽  
Author(s):  
Sergey V. Dvinskikh ◽  
Vasco Castro ◽  
Dick Sandström
Keyword(s):  
Lipid Membranes ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Studies ◽  
Sample Rotation ◽  
Angle Spinning

scholarly journals General Guidelines for Sample Preparation Strategies in HR-µMAS NMR-based Metabolomics of Microscopic Specimens

Metabolites ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 54 ◽  
Author(s):  
Lucas-Torres ◽  
Bernard ◽  
Huber ◽  
Berthault ◽  
Nishiyama ◽  
...  
Keyword(s):  
High Resolution ◽  
Sample Preparation ◽  
Bulk Sample ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Studies ◽  
Sample Rotation ◽  
Angle Spinning ◽  
Bioanalytical Techniques ◽  
General Studies

The study of the metabolome within tissues, organisms, cells or biofluids can be carried out by several bioanalytical techniques. Among them, nuclear magnetic resonance (NMR) is one of the principal spectroscopic methods. This is due to a sample rotation technique, high-resolution magic angle spinning (HR-MAS), which targets the analysis of heterogeneous specimens with a bulk sample mass from 5 to 10 mg. Recently, a new approach, high-resolution micro-magic angle spinning (HR-μMAS), has been introduced. It opens, for the first time, the possibility of investigating microscopic specimens (<500 μg) with NMR spectroscopy, strengthening the concept of homogeneous sampling in a heterogeneous specimen. As in all bioanalytical approaches, a clean and reliable sample preparation strategy is a significant component in designing metabolomics (or -omics, in general) studies. The sample preparation for HR-μMAS is consequentially complicated by the μg-scale specimen and has yet to be addressed. This report details the strategies for three specimen types: biofluids, fluid matrices and tissues. It also provides the basis for designing future μMAS NMR studies of microscopic specimens.

scholarly journals High-resolution magic angle spinning NMR studies for metabolic characterization of Arabidopsis thaliana mutants with enhanced growth characteristics

PLoS ONE ◽  
2018 ◽  
Vol 13 (12) ◽  
pp. e0209695 ◽  
Author(s):  
Dieuwertje Augustijn ◽  
Niels van Tol ◽  
Bert J. van der Zaal ◽  
Huub J. M. de Groot ◽  
A. Alia
Keyword(s):  
Arabidopsis Thaliana ◽  
High Resolution ◽  
Magic Angle Spinning ◽  
Growth Characteristics ◽  
Magic Angle ◽  
Nmr Studies ◽  
Angle Spinning

Characterization of metallurgical-grade aluminas and their precursors by 27Al NMR and XRD

2007 ◽  
Vol 85 (10) ◽  
pp. 889-897 ◽  
Author(s):  
Linus M Perander ◽  
Zoran D Zujovic ◽  
Tania Groutso ◽  
Margaret M Hyland ◽  
Mark E Smith ◽  
...  
Keyword(s):  
Solid State ◽  
High Field ◽  
Structural Complexity ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Studies ◽  
Transition Alumina ◽  
Angle Spinning ◽  
Alpha Alumina

The structure of metallurgical- or smelter-grade aluminas (MGAs) is complex and poorly understood. Ultra-high-field solid-state 27Al NMR results on industrial as well as on laboratory-prepared aluminas are discussed in relation to XRD results. It is demonstrated that high-field NMR can effectively be used to quantify the proportion of the thermodynamically stable alpha-alumina phase in these materials. The results demonstrate that 27Al NMR is a vital adjunct to XRD methods to quantify the transition alumina phases that invariably dominate the MGAs. The nature of the disorder in these materials, determined by 27Al NMR, is also compared with literature data, such as XANES and EXAFS studies, on typical laboratory-prepared materials. The utility of 27Al NMR studies to provide new insight into the structural complexity of metallurgical aluminas is shown.Key words: solid-state magic-angle-spinning NMR, metallurgical-grade alumina, transition alumina, gamma-alumina, coordination number.

scholarly journals Sample spinning to mitigate polarization artifact and interstitial-vacancy imbalance in ion-beam irradiation

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Cui-Lan Ren ◽  
Yang Yang ◽  
Yong-Gang Li ◽  
Ping Huai ◽  
Zhi-Yuan Zhu ◽  
...  
Keyword(s):  
Ion Beam ◽  
Neutron Radiation ◽  
Magic Angle Spinning ◽  
Natural Material ◽  
Magic Angle ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Beam Radiation ◽  
Sample Rotation ◽  
Angle Spinning

AbstractAccelerator-based ion-beam irradiation has been widely used to mimic the effects of neutron radiation damage in nuclear reactors. However, ion radiation is most often monodisperse in the incoming ions’ momentum direction, leading to excessive polarization in defect distribution, while the scattering under neutron irradiation is often more isotropic and has less radiation-induced polarization. Mitigation of the excess-polarization as well as the damage non-uniformity artifact might be crucial for making the simulation of neutron radiation by ion-beam radiation more realistic. In this work, a general radiation polarization theory in treating radiation as external polar stimuli is established to understand the natural material responses in different contexts, and the possibility to correct the defect polarization artifact in ion-beam irradiation. Inspired by Magic Angle Spinning in Nuclear Magnetic Resonance, we present a precise sample spinning strategy to reduce the point-defect imbalance effect in ion-beam irradiation. It can be seen that with optimized surface inclination angle and the axis of sample rotation, the vacancy-interstitial population imbalance, as well as the damage profile non-uniformity in a designated region in the target are both reduced. It is estimated that sample spinning frequency on the order of kHz should be sufficient to scramble the ion momentum monodispersity for commonly taken ion fluxes and dose rates, which is experimentally feasible.

Proton Magic Angle Spinning NMR Reveals New Features in Photodynamically Treated Bacteria

2003 ◽  
Vol 58 (5-6) ◽  
pp. 401-407 ◽  
Author(s):  
Yngve Johansen ◽  
Hege Christin Widerøe ◽  
Jostein Krane ◽  
Anders Johnsson ◽  
Anders Johnsson
Keyword(s):  
Blue Light ◽  
Glycine Betaine ◽  
Aminolevulinic Acid ◽  
Irradiation Time ◽  
Regulatory Volume Decrease ◽  
Magic Angle Spinning ◽  
Eukaryotic Cells ◽  
Magic Angle ◽  
Nmr Studies ◽  
Angle Spinning

Abstract The bacterium Propionibacterium acnes is light-sensitive due to porphyrin-induced photosensitization. The light sensitivity increases with incubation of 5-aminolevulinic acid, ALA. For the first time, 1H magic angle spinning NMR spectroscopy is used to describe the photoinduced changes in the bacterium after ALA incubation. Successful photosensitization was performed with light-emitting diodes in the blue and red regions (430 and 654 nm, respectively). The irradiation setup, suitable for irradiation of bacaterium suspensions in petri dishes is described. For NMR studies blue light diodes with about 90 μmol/m2s were chosen. After blue light irradiation, the endogenous glycine betaine, proline, glutamate and choline levels in P. acnes decreased with increasing irradiation time. For sublethal light doses (50% survival fraction), the endogenous glycine betaine level decreased 80% on average. The corresponding percentages for proline, choline and glutamate were about 40, 25 and 10, respectively. It is hypothesized that the irradiation, inducing porphyrin photosensitization amplified by ALA incubation, leads to elimination of the osmolyte glycine betaine and possibly also proline by so-called regulatory volume decrease (RVD) mechanisms. These mechanisms are known to be active in several prokaryotic and eukaryotic cells when exposed to hypotonic stress. They are also known to be present in several eukaryotic cells during photodynamic therapy (PDT) exposure leading to hypotonoc stress. The findings contribute to the knowledge of the inactivation mechanisms of P. acnes in photosensitization, and could therefore be of interest in the efforts to use PDT as treatment of the acne disease.

Metabolic Profiling of Lung Granuloma inMycobacterium tuberculosisInfected Guinea Pigs: Ex vivo1H Magic Angle Spinning NMR Studies

2011 ◽  
Vol 10 (9) ◽  
pp. 4186-4195 ◽  
Author(s):  
B. S. Somashekar ◽  
Anita G. Amin ◽  
Christopher D. Rithner ◽  
JoLynn Troudt ◽  
Randall Basaraba ◽  
...  
Keyword(s):  
Metabolic Profiling ◽  
Guinea Pigs ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Studies ◽  
Angle Spinning
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