Centerband-only-detection-of-exchange 31P nuclear magnetic resonance and phospholipid lateral diffusion: theory, simulation and experiment

2015 ◽  
Vol 17 (38) ◽  
pp. 25160-25171 ◽  
Author(s):  
Angel Lai ◽  
Qasim Saleem ◽  
Peter M. Macdonald
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Liquid Crystalline ◽  
Diffusion Theory ◽  
Lateral Diffusion ◽  
Liquid Crystalline Phases ◽  
Simulation And Experiment ◽  
Spherical Vesicles ◽  
Lateral Diffusion Coefficient

Theory of CODEX 31P NMR lateral diffusion coefficient measurements on phospholipids in spherical vesicles is described and used to simulate experimental results on DMPC in both the gel and liquid-crystalline phases.

Deuterium and phosphorus-31 nuclear magnetic resonance of cholesteryl palmitate in dipalmitoylphosphatidylcholine model membranes

1980 ◽  
Vol 58 (23) ◽  
pp. 2433-2441 ◽  
Author(s):  
Robert J. Cushley ◽  
Heiner Gorrissen ◽  
Stephen R. Wassall
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Liquid Crystalline ◽  
Acyl Chain ◽  
Relaxation Times ◽  
Average Diameter ◽  
Low Degree ◽  
Cholesteryl Palmitate ◽  
Degree Of Order ◽  
Ester Chain

Cholesteryl palmitate (CP) bas been incorporated into vesicles of dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylcholine/20 mol% cholesterol, in amounts up to 5 mol%. By means of 31P lanthanide induced shifts the average diameter of these vesicles was calculated to be ~270 Å.The 2H spectral linewidths of selectively deuterated CP incorporated into liquid crystalline dipalmitoylphosphatidylcholine vesicles are ≤ 150 Hz, implying a low degree of order for the ester acyl chain. Addition of 20 mol% cholesterol to the vesicles increases the linewidths which, nevertheless, remain ≤ 185 Hz. The corresponding 2H longitudinal relaxation times (≤ 450 ms) indicate that the fast segmental motions of the ester chain are slower than for the phospholipid chains.

scholarly journals On the Theory of Electron Diffusion in Electrostatic Fields in Gases

1974 ◽  
Vol 27 (2) ◽  
pp. 195 ◽  
Author(s):  
HR Skullerud
Keyword(s):  
Diffusion Coefficient ◽  
Boltzmann Equation ◽  
Diffusion Equation ◽  
Diffusion Tensor ◽  
Lateral Diffusion ◽  
Mean Square ◽  
Electrostatic Fields ◽  
The Mean ◽  
Lateral Diffusion Coefficient

The motion of electrons in a gas in the presence of large electron density gradients has been studied theoretically, starting from the two-term expansion of the Boltzmann equation. The effects of material boundaries have not been considered. An electron swarm released as a b-function in space and with an equilibrium energy distribution is found initially to develop as a spheroid with dimensions determined by the lateral diffusion coefficient. It subsequently passes through a stage involving a slowly decaying pear-shaped deformation, before ultimately becoming an ellipsoid with dimensions determined by the longitudinal and lateral components of the diffusion tensor. Numerical values cited in the literature for the long-term deviations from the mean square widths predicted by the diffusion equation have been found to be in error by factors of 10 or more.

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