Characterization of bleomycin lung injury by nuclear magnetic resonance: Correlation between NMR relaxation times and lung water and collagen content

2002 ◽  
Vol 47 (2) ◽  
pp. 246-256 ◽  
Author(s):  
Antonio G. Cutillo ◽  
Pei H. Chan ◽  
David C. Ailion ◽  
Suetaro Watanabe ◽  
Narayanam V. Rao ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Lung Injury ◽  
Relaxation Times ◽  
Nmr Relaxation ◽  
Collagen Content ◽  
Lung Water ◽  
Nmr Relaxation Times ◽  
Nuclear Magnetic

Rapid, reliable in vivo assays of human phosphate metabolites by nuclear magnetic resonance.

1989 ◽  
Vol 35 (3) ◽  
pp. 392-395 ◽  
Author(s):  
P A Bottomley ◽  
C J Hardy
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Nmr Relaxation ◽  
Fast Method ◽  
Human Volunteers ◽  
Nmr Relaxation Times ◽  
The Subject ◽  
Nuclear Magnetic

Abstract This accurate, reliable, and fast method of assaying absolute concentrations of phosphate metabolites noninvasively in living tissue, including that of humans, combines 31P nuclear magnetic resonance (NMR) spectroscopy and 1H NMR imaging. The images are used to measure the areas of metabolite-bearing tissue in selected sections through the subject, and 31P spectra are acquired from the same section, together with a concentration reference located on the periphery. Metabolite concentrations are calculated from the ratios of areas and integrated signal intensities. Apparatus and protocol are designed to eliminate corrections due to magnetic field nonuniformities and NMR relaxation times. Mean (and SD) concentrations of adenosine triphosphate (ATP), phosphocreatine, and inorganic phosphate (Pi) measured in the brains of 15 normal adult human volunteers with a 1.5-T NMR system were 3.03 (0.49), 5.18 (0.89), and 1.5 (0.7) mmol per liter of wet tissue, respectively. Acquisition times of only a few minutes should facilitate metabolic studies of patients with disorders in limbs and brain, particularly those affecting entire organs.

scholarly journals Preliminary magnetic resonance relaxometric analysis of Fricke gel dosimeters produced with polyvinyl alcohol and glutaraldehyde

2017 ◽  
Vol 32 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Salvatore Gallo ◽  
Giorgio Collura ◽  
Giuseppina Iacoviello ◽  
Anna Longo ◽  
Luigi Tranchina ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Polyvinyl Alcohol ◽  
Dose Range ◽  
Relaxation Times ◽  
Ion Concentration ◽  
Nuclear Magnetic Resonance Relaxometry ◽  
New Formulation ◽  
Nuclear Magnetic

This work describes the preliminary analysis of Fricke gels dosimeters characterized by a new formulation making use of a matrix of polyvinyl alcohol cross-linked by adding glutaraldehyde and analyzed by means of nuclear magnetic resonance relaxometry. In previous optical studies, these gels have shown promising dosimetric features in terms of photon sensitivity and low diffusion of ferric ions produced after irradiation. In this work, we used a portable nuclear magnetic resonance relaxometer to measure the relaxation times (which are important for dosimetric applications) of these gel materials. For this purpose, we performed a study for optimizing the acquisition parameters with a nuclear magnetic resonance relaxometer. Gel samples were exposed to clinical 6 MV photons in the dose range between 0 and 20 Gy. Nuclear magnetic resonance relaxometry measurements were per- formed and the sensitivity to photon beams was measured for various values of the Fe2+ ion concentration. The analyses pointed out that the MR signal increases as the Fe2+ content in- creases and the increase is about 75 % when the concentration of Fe2+ ions is increased from 0.5 mM to 2.5 mM. Furthermore, the sensitivity improvement achieved with increasing the Fe2+ concentration is about 60 %. This paper shows that the portable nuclear magnetic resonance relaxometer used for analysis of porous materials can be used for characterization of these dosimetric gels and this study can be considered as the first step for the characterization of these dosimeters which in future could be used for 3-D dose mapping in clinical applications.

scholarly journals Characterization of moisture in acetylated and propionylated radiata pine using low-field nuclear magnetic resonance (LFNMR) relaxometry

Holzforschung ◽  
2018 ◽  
Vol 72 (3) ◽  
pp. 225-233 ◽  
Author(s):  
Greeley Beck ◽  
Emil Engelund Thybring ◽  
Lisbeth Garbrecht Thygesen ◽  
Callum Hill
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cell Wall ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Radiata Pine ◽  
Saturation Point ◽  
Weight Percentage ◽  
Low Field ◽  
Nuclear Magnetic

AbstractMoisture in radiata pine (Pinus radiataD. Don) earlywood (EW), which was acetylated or propionylated to various degrees, was measured by low-field nuclear magnetic resonance (LFNMR) relaxometry. Spin-spin relaxation times (T2) were determined for fully saturated samples at 22 and −18°C.T2values for EW lumen water increased with increasing acetylation weight percentage gain (WPG), perhaps caused by the less hydrophilic acetylated wood (AcW) surface. Cell wall water (WCW) and the water in pits and small voids also showed increasingT2values as a function of WPG but with a weaker tendency. A possible explanation is the counteracting effects of decreased hydrophilicity and reduced moisture content (MC) of these water populations at higher levels of acetylation. The evaluation of propionylation on WCWT2data was complicated by peak splitting in the relaxation spectrum. ConstantT2values for void water populations at various WPG levels for propionylated samples indicate a modification gradient in the cell wall. Fiber saturation point (FSP) was significantly reduced by both modifications. Slightly higher FSP values for propionylated samples suggest that physical bulking is not the only factor causing moisture exclusion in AcW. But this interpretation is tentative because of the possibility of cell wall damage caused by propionylation.

scholarly journals Nuclear Magnetic Resonance (NMR) Characterization of a Polymerized Ionic Liquid Electrolyte Material

2012 ◽  
Vol 1440 ◽  
Author(s):  
A.L. Michan ◽  
G.T.M. Nguyen ◽  
O. Fichet ◽  
F. Vidal ◽  
C. Vancaeyzeele ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Diffusion Coefficients ◽  
Polymer Network ◽  
Relaxation Times ◽  
Solid Polymer ◽  
Pulsed Field ◽  
Nuclear Magnetic

ABSTRACTSolid electrolyte materials have the potential to improve performance and safety characteristics of lithium-ion batteries by replacing conventional solvent-based electrolytes. A candidate solid polymer electrolyte, AMLi/PEGDM, has been synthesized by crosslinking an anionic monomer AMLi, with poly(ethylene glycol) dimethacrylate. The main goal of the synthesis is to produce a single-ion conducting polymer network where lithium cations can move freely and fluorinated anions are immobilized as part of the polymer network. A comprehensive characterization of anion and cation mobility in the resulting material is therefore required. Using pulsed-field gradient nuclear magnetic resonance (PFG-NMR), we are able to measure and quantify the individual diffusion coefficients of mobile species in the material (19F and 7Li) and confirm the extent to which the fluorinated anionic component is immobilized. We have characterized dry (σ~3.0 x10-7 S/cm at 30°C) and propylene carbonate (PC) saturated gel (σ~1.0x10-4 S/cm at 30°C) samples. Experimental results include NMR spin-spin and spin-lattice relaxation times in addition to diffusion coefficient measurements over a temperature range up to 100°C. Practically, the diffusion measurements are extremely challenging, as the spin-spin (T2) relaxation times are very short, necessitating the development of specialized pulsed-field gradient apparatus. Diffusion coefficients for the most mobile components of the lithium cations and fluorinated anions at 100°C in dry membranes have been found to be 3.4 x10-8 cm2/s and 2.1 x10-8 cm2/s respectively. These results provide valuable insight into the conduction mechanisms in these materials, and will drive further optimization of solid polymer electrolytes.

Laboratory studies of the effect of sorbed oil on proton nuclear magnetic resonance

Geophysics ◽  
2003 ◽  
Vol 68 (3) ◽  
pp. 942-948 ◽  
Author(s):  
Traci R. Bryar ◽  
Rosemary J. Knight
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Surface Area ◽  
Pore Space ◽  
Relaxation Times ◽  
Nmr Relaxation ◽  
Proton Nuclear Magnetic Resonance ◽  
Surface Relaxivity ◽  
Saturated Sands ◽  
Nuclear Magnetic

Proton NMR (nuclear magnetic resonance) measurements were made of T1 and T2 relaxation times of water in saturated sands containing varying amounts of sorbed oil on the grain surfaces. The porosity, surface area, and grain density of the sands and the relaxation times of the extracted pore water were also determined experimentally. Sorption of oil changed the relaxation time of water in the saturated sands through changes in surface area and surface relaxivity, the parameter used to quantify the ability of the surface of the pore space to reduce NMR relaxation times. In some cases the addition of oil to the surfaces decreased the surface area, an observation that suggested the oil was coating the surface in a way to reduce surface roughness. When larger amounts of oil were added to the surface, surface area increased. The changes in surface relaxivity with the amount of sorbed oil were governed by the relaxivity of the clean, oil‐free surfaces. In the Wedron sand, with a surface relaxivity typical of naturally occurring sands, the relaxivity decreased with the addition of oil to the surface of the sand grains. In the A–A sand, a clean, pure quartz sand, the relaxivity increased from a very low value for the oil‐free sample to a higher value, interpreted to be that of the oil surface.

Research of Calibration Curves NMR Relaxation Times of Nanoparticles Gadolinium Oxide

2014 ◽  
Vol 487 ◽  
pp. 94-97
Author(s):  
Chun Lin Yang ◽  
Mei Gui Ou ◽  
Jia Zeng ◽  
Xiu Qun Yang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Nmr Relaxation ◽  
Gadolinium Oxide ◽  
Free Ions ◽  
Calibration Curves ◽  
Relaxation Measurements ◽  
Nmr Relaxation Times

In this paper, a method of assay based on NMR (Nuclear Magnetic Resonance) measurements was developed. A protocol for the dissolution of gadolinium oxide cores and calibration curves were established for Nanoparticles gadolinium oxide. After optimization this method was used for several applications such as checking the concentration in colloids after dialysis or controlling the concentration and the form (oxides or free ions) of lanthanides after in vivo injection. The Experiments showed the samples did not present any suspension or deposit after the dissolution treatment, The concentrations calculated from relaxation measurements are very close to the concentrations measured . According to measure relaxation times T1 and T2, we can approximately determinate the gadolinium concentration. .

Assessment of Lung Water Distribution by Nuclear Magnetic Resonance: A New Method for Quantifying and Monitoring Experimental Lung Injury

1988 ◽  
Vol 137 (6) ◽  
pp. 1371-1378 ◽  
Author(s):  
Antonio G. Cutillo ◽  
Alan H. Morris ◽  
David C. Ailion ◽  
Thomas A. Case ◽  
Carl H. Durney ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Lung Injury ◽  
Water Distribution ◽  
New Method ◽  
Lung Water ◽  
Nuclear Magnetic

An emerging technology: Nuclear magnetic resonance microscopy

1988 ◽  
Vol 46 ◽  
pp. 1000-1001
Author(s):  
M.J. Hennessy ◽  
E. Kwok
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Basic Research ◽  
Local Environment ◽  
Magnetic Resonance Images ◽  
Nmr Microscopy ◽  
Mri Scans ◽  
Temperature Relaxation ◽  
Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

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