Proton Hyperfine Structure at Magnetic Fields below ∼ 100 G in Electron Magnetic Resonance Absorptions by Triplet States of Aromatic Molecules

1969 ◽  
Vol 51 (4) ◽  
pp. 1664-1665 ◽  
Author(s):  
Roger E. Gerkin ◽  
Arthur M. Winer
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Hyperfine Structure ◽  
Electron Magnetic Resonance ◽  
Triplet States ◽  
Aromatic Molecules

Nuclear orientation and nuclear cooling experiements in Oxford and Helsinki Part 2. Progress from 1945 to 1970

2003 ◽  
Vol 57 (3) ◽  
pp. 323-330 ◽  
Author(s):  
B. Bleaney ◽  
O. V. Lounasmaa
Keyword(s):  
Magnetic Resonance ◽  
Hyperfine Structure ◽  
Radioactive Isotope ◽  
Nuclear Orientation ◽  
Charge Conjugation ◽  
Electron Magnetic Resonance ◽  
Magnetic Alignment

The development of electron magnetic resonance by E. Zavoisky in 1945–46, and the discovery of hyperfine structure in paramagnetic compounds, soon found applications in cryogenics. Methods suggested for nuclear orientation were followed by experiments on magnetic alignment with the use of the radioactive isotope cobalt–60. These showed that the principles of both parity and charge conjugation are violated. Nuclear cooling reached microkelvin temperatures. † Deceased.

Nuclear magnetic resonance microscopy

1989 ◽  
Vol 47 ◽  
pp. 828-829
Author(s):  
Paul C. Lauterbur
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Signal To Noise ◽  
Field Gradients ◽  
Useful Signal ◽  
Magnetic Field Gradients ◽  
Observation Times ◽  
Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

Calcium efflux of plasma membrane vesicles exposed to ELF magnetic fields-test of a nuclear magnetic resonance interaction model

2012 ◽  
Vol 33 (7) ◽  
pp. 535-542 ◽  
Author(s):  
Wenjun J. Sun ◽  
Mehri Kaviani Mogadam ◽  
Marianne Sommarin ◽  
Henrietta Nittby ◽  
Leif G. Salford ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Plasma Membrane ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Interaction Model ◽  
Membrane Vesicles ◽  
Resonance Interaction ◽  
Calcium Efflux ◽  
Plasma Membrane Vesicles ◽  
Nuclear Magnetic
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