Modification of 4 Mhz N.M.R. Water Proton Relaxation Times in Very High Diluted Aqueous Solutions

1997 ◽  
pp. 95-110 ◽  
Author(s):  
J. L. Demangeat ◽  
P. Gries ◽  
B. Poitevin
Keyword(s):  
Aqueous Solutions ◽  
Relaxation Times ◽  
Water Proton ◽  
Proton Relaxation ◽  
Very High

Temperature Dependence of Proton Relaxation Times in Aqueous Solutions of Paramagnetic Ions

1959 ◽  
Vol 30 (4) ◽  
pp. 950-956 ◽  
Author(s):  
Robert A. Bernheim ◽  
Thomas H. Brown ◽  
H. S. Gutowsky ◽  
D. E. Woessner
Keyword(s):  
Aqueous Solutions ◽  
Temperature Dependence ◽  
Relaxation Times ◽  
Proton Relaxation ◽  
Paramagnetic Ions

Characterization of periventricular edema in normal-pressure hydrocephalus by measurement of water proton relaxation times

1990 ◽  
Vol 73 (6) ◽  
pp. 864-870 ◽  
Author(s):  
Norihiko Tamaki ◽  
Takayuki Shirakuni ◽  
Kazumasa Ehara ◽  
Satoshi Matsumoto
Keyword(s):  
Relaxation Time ◽  
White Matter ◽  
Gray Matter ◽  
Normal Pressure Hydrocephalus ◽  
Relaxation Times ◽  
Normal Pressure ◽  
Water Proton ◽  
Proton Relaxation ◽  
Csf Shunting ◽  
Significant Difference

✓ The magnetic resonance longitudinal relaxation time (T1) and transverse relaxation time (T2) of the water proton of the periventricular white and cortical gray matter were measured for 17 control patients and 21 patients with suspected normal-pressure hydrocephalus (NPH). Of the latter group, 14 showed good response to shunting (true-NPH group) and seven showed no response (false-NPH group). In the true-NPH group, both the T1 and the T2 of the periventricular white matter were significantly prolonged compared to the control values, and slowly shortened after cerebrospinal fluid (CSF) shunting. The true-NPH group showed significantly longer T1 and T2 of the white matter than did the false-NPH group. The T1 and T2 of the white matter were longer than those of the gray matter in this group, which was the reverse of the relationship observed in the control patients. In the white matter of the false-NPH group, there was a significant prolongation of T1 only; no difference was seen in the T2 compared to control values. There was no change in either T1 or T2 of this region after CSF shunting. The false-NPH group showed no significant difference in either T1 or T2 between the white and the gray matter. There was no difference in either T1 or T2 of the gray matter between the false-NPH and control groups or between preshunt and postshunt measurements in each patient group. It is suggested that a distinction between true- and false-NPH, which cannot be made from the radiographic appearance alone, may be possible from measurement of relaxation times. The mechanism of varied relaxation behavior between two entities may be explained by a difference in properties of the biological water and its environment.

Influence of glycogen on water proton relaxation times

1986 ◽  
Vol 3 (3) ◽  
pp. 463-466 ◽  
Author(s):  
J. C. Gore ◽  
M. S. Brown ◽  
C. T. Mizumoto ◽  
I. M. Armitage
Keyword(s):  
Relaxation Times ◽  
Water Proton ◽  
Proton Relaxation

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

Inspecting Insulin Products Using Water Proton NMR. I. Noninvasive vs Invasive Inspection

2021 ◽  
pp. 193229682110238
Author(s):  
Marc B. Taraban ◽  
Yilin Wang ◽  
Katharine T. Briggs ◽  
Yihua Bruce Yu
Keyword(s):  
Quality Control ◽  
Relaxation Rate ◽  
Drug Product ◽  
Proton Nmr ◽  
Water Proton ◽  
Proton Relaxation ◽  
Content Uniformity ◽  
Biologic Drugs ◽  
Insulin Solution ◽  
Insulin Pens

Background: There is a clear need to transition from batch-level to vial/syringe/pen-level quality control of biologic drugs, such as insulin. This could be achieved only by noninvasive and quantitative inspection technologies that maintain the integrity of the drug product. Methods: Four insulin products for patient self-injection presented as prefilled pens have been noninvasively and quantitatively inspected using the water proton NMR technology. The inspection output is the water proton relaxation rate R2(1H2O), a continuous numerical variable rather than binary pass/fail. Results: Ten pens of each product were inspected. R2(1H2O) displays insignificant variation among the 10 pens of each product, suggesting good insulin content uniformity in the inspected pens. It is also shown that transferring the insulin solution out of and then back into the insulin pen caused significant change in R2(1H2O), presumably due to exposure to O2 in air. Conclusions: Water proton NMR can noninvasively and quantitatively inspect insulin pens. wNMR can confirm product content uniformity, but not absolute content. Its sensitivity to sample transferring provides a way to detect drug product tampering. This opens the possibility of inspecting every pen/vial/syringe by manufacturers and end-users.

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