scholarly journals Intracellular and Extracellular Spaces of Normal Adult Rat Brain Determined from the Proton Nuclear Magnetic Resonance Relaxation Times

1987 ◽  
Vol 7 (5) ◽  
pp. 552-556 ◽  
Author(s):  
Munetaka Haida ◽  
Masahiro Yamamoto ◽  
Hideshi Matsumura ◽  
Yukito Shinohara ◽  
Minoru Fukuzaki
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Rat Brain ◽  
Brain Tissue ◽  
Relaxation Times ◽  
Proton Nuclear Magnetic Resonance ◽  
Water Molecules ◽  
Normal Rat ◽  
Rat Brain Tissue ◽  
Nuclear Magnetic

The nuclear magnetic resonance method was used to investigate the state of water molecules in normal rat brain tissue in vitro. The transverse magnetization decay curve (TMDC) of the fresh brain tissue of adult rats (8- or 10-weeks-old) was biexponential, which could be interpreted in terms of two distinct transverse relaxation times ( T2). Several factors that may affect the TMDC are discussed. It was concluded that the fast and slow components of T2 correspond to those of the water molecules of the intracellular and the extracellular spaces of normal rat brain tissue, respectively.

scholarly journals A nuclear magnetic resonance study of water in aggrecan solutions

2016 ◽  
Vol 3 (3) ◽  
pp. 150705 ◽  
Author(s):  
Richard J. Foster ◽  
Robin A. Damion ◽  
Thomas G. Baboolal ◽  
Stephen W. Smye ◽  
Michael E. Ries
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Rate ◽  
Activation Energies ◽  
Proton Nuclear Magnetic Resonance ◽  
Water Molecules ◽  
Transverse Relaxation Rate ◽  
Relaxation Rates ◽  
Transverse Relaxation ◽  
Nuclear Magnetic

Aggrecan, a highly charged macromolecule found in articular cartilage, was investigated in aqueous salt solutions with proton nuclear magnetic resonance. The longitudinal and transverse relaxation rates were determined at two different field strengths, 9.4 T and 0.5 T, for a range of temperatures and aggrecan concentrations. The diffusion coefficients of the water molecules were also measured as a function of temperature and aggrecan concentration, using a pulsed field gradient technique at 9.4 T. Assuming an Arrhenius relationship, the activation energies for the various relaxation processes and the translational motion of the water molecules were determined from temperature dependencies as a function of aggrecan concentration in the range 0–5.3% w/w. The longitudinal relaxation rate and inverse diffusion coefficient were approximately equally dependent on concentration and only increased by upto 20% from that of the salt solution. The transverse relaxation rate at high field demonstrated greatest concentration dependence, changing by an order of magnitude across the concentration range examined. We attribute this primarily to chemical exchange. Activation energies appeared to be approximately independent of aggrecan concentration, except for that of the low-field transverse relaxation rate, which decreased with concentration.

Detecting and quantifying organic contaminants in sediments with nuclear magnetic resonance

Geophysics ◽  
2016 ◽  
Vol 81 (6) ◽  
pp. EN87-EN97 ◽  
Author(s):  
Emily L. Fay ◽  
Rosemary J. Knight
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Crude Oil ◽  
Organic Contaminants ◽  
Relaxation Times ◽  
Proton Nuclear Magnetic Resonance ◽  
Bulk Fluid ◽  
Sediment Samples ◽  
Water Signal ◽  
Nuclear Magnetic

We have conducted proton nuclear magnetic resonance (NMR) measurements of relaxation times [Formula: see text] and [Formula: see text] as well as the diffusion coefficient [Formula: see text] to detect and quantify gasoline, diesel, crude oil, and trichloroethylene (TCE) in sediment samples containing water. The sediment samples were coarse sand, fine sand, and a sand-clay mixture. We found that water, gasoline, diesel, and crude oil all exhibited similar signal amplitudes per unit volume, whereas TCE exhibited one-tenth the signal. The ability to use [Formula: see text] measurements to distinguish the contaminant signal from the water signal depended on the bulk-fluid properties as well as the sediment texture and grain size. In the [Formula: see text] distributions for samples containing equal volumes of contaminant and water, the contaminant signal could be resolved for crude oil in sand and for gasoline and TCE in the sand-clay mixture. Adding the diffusion measurement, using either pulsed or static gradients, made it possible to distinguish diesel and crude oil in all of the samples due to the large differences between the [Formula: see text] of the contaminants and water. From the diffusion measurements, we were able to accurately quantify diesel and crude oil volumes ranging from 1% to 17% of the total sample volume. These methods could be applied in the field using NMR logging tools to quantify and monitor subsurface contamination.

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