ChemInform Abstract: APPLICATIONS OF PULSED NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY. PART 12. A SURVEY OF THE PROTON SPIN-LATTICE RELAXATION RATES OF SELECTED FURANOSE DERIVATIVES

1981 ◽  
Vol 12 (1) ◽  
Author(s):  
K. BOCK ◽  
L. D. HALL ◽  
C. PEDERSEN
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Resonance Spectroscopy ◽  
Relaxation Rates ◽  
Spin Lattice ◽  
Pulsed Nuclear Magnetic Resonance

Nuclear magnetic resonance of 169 Tm (enhanced) and 31 P in TmPO 4

1983 ◽  
Vol 387 (1792) ◽  
pp. 75-90 ◽  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Energy Levels ◽  
Lattice Relaxation ◽  
Simple Calculation ◽  
Spin Lattice Relaxation ◽  
Field Calculation ◽  
Relaxation Rates ◽  
Spin Lattice ◽  
Nuclear Magnetic

The enhanced nuclear magnetic resonance (n. m. r.) spectrum of 169 Tm ( I = ½) in the tetragonal compound TmPO 4 has been measured from 1.6 K to 30 K. It is highly anisotropic, with γ /2π = 11.34 and 276MHzT -1 , parallel and perpendicular to the c -axis respectively, at the lowest temperatures. The corresponding values of the Van Vleck electronic susceptibility per ion are 0.0231 and 0.805 μ B T -1 . Above 4 K the values of γ /2π become temperature dependent as excited levels become populated, and the results are discussed in the light of a crystal field calculation of the energy levels and wave functions. The n. m. r. spectrum of 31 P ( I = ½) is shown to exhibit an anisotropic paramagnetic shift, mainly dipolar in origin, exactly proportional to the electronic susceptibility of the Tm 3+ ions, and this is used to extrapolate the measurement of γ for 169 Tm up to 64 K in the perpendicular direction. A simple calculation of the direct process for spin-lattice relaxation shows that this is orders of magnitude too slow to account for the observed relaxation rates, which must be ascribed to the presence of paramagnetic impurities.

NMR Investigations of the Bulk Metallic Glass Zr55Cu30Al10Ni5

1998 ◽  
Vol 554 ◽  
Author(s):  
W. Hoffmann ◽  
M. Baenitz ◽  
K. Lüders ◽  
A. Gebert ◽  
J. Eckert ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Relaxation Rates ◽  
Structural Investigations ◽  
Spin Lattice ◽  
Local Environments

AbstractNuclear magnetic resonance (NMR) was applied for structural investigations of the bulk metallic glass system Zr55Cu30A110Ni5. The 63Cu as well as 27Al resonance was used. For both nuclei, two different spin-lattice relaxation rates were found which can be explained by different local environments of the nuclei.

Na(+)-K(+)-ATPase in endothelial cell energetics: 23Na nuclear magnetic resonance and calorimetry study

1995 ◽  
Vol 268 (1) ◽  
pp. H351-H358 ◽  
Author(s):  
M. L. Gruwel ◽  
C. Alves ◽  
J. Schrader
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Vascular Endothelial Cells ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Shift Reagent ◽  
Spin Lattice Relaxation ◽  
Resonance Spectroscopy ◽  
Spin Lattice ◽  
Nuclear Magnetic

Sodium flux rate and energy consumption of the Na(+)-K+ pump in vascular endothelial cells of porcine aorta grown on micro-carrier beads were studied using a combination of nuclear magnetic resonance spectroscopy of intracellular 23Na and microcalorimetry. The Na+ flux into the cells was determined in the presence of the shift reagent Dy(P3O10)2(7-), while the Na(+)-K+ pump was inhibited with ouabain. Basal Na+ influx was 17 +/- 3 nmol.min-1.mg protein-1, and intracellular Na+ concentration was 23.5 +/- 3.8 mM, resulting in a complete exchange of intracellular Na+ within 5–6 min. Spin-lattice relaxation time (T1) measurements of intracellular Na+ showed a T1 of 19 +/- 1 ms under basal conditions and a T1 of 26.2 +/- 1.6 ms after pump inhibition with 50 microM ouabain. Such an increase is typical for a system in which the total amount of Na+ increases but where the amount of bound Na+ remains constant. The Na+ ionophore nystatin maximally increased the Na(+)-K+ pump rate about twofold, whereas the amount of intracellular Na+ only increased 14%. With microcalorimetry a cellular heat flux of 183 +/- 18 microW per mg endothelial protein was determined, which relates to 7.6 microW/mg endothelial protein generated by the Na(+)-K(+)-adenosinetriphosphatase. Our data demonstrate that small intracellular changes of Na+ can stimulate the endothelial Na(+)-K+ pump activity. The contribution of the Na(+)-K+ pump to total endothelial energy expenditure is approximately 4-5%.

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