scholarly journals О возможности использования спектрального анализа для исследования структуры линии сигнала ядерного магнитного резонанса

2021 ◽  
Vol 129 (5) ◽  
pp. 608
Author(s):  
В.В. Давыдов ◽  
В.Д. Купцов ◽  
В.И. Дудкин ◽  
А.В. Мороз ◽  
С.С. Макеев
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Weak Magnetic Field ◽  
Experimental Studies ◽  
Condensed Medium ◽  
Weak Field ◽  
Nmr Spectrum ◽  
Nuclear Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The necessity of recording the spectrum of nuclear magnetic resonance in a weak field from a condensed medium with express control of its state is substantiated. The conditions are established that allow the registration of nuclear magnetic resonance spectra in a weak field. A new design of a small-sized nuclear magnetic spectrometer for recording the NMR spectrum in a weak magnetic field from a volume of a condensed medium of about 3.0 ml has been developed. The results of experimental studies of various media are presented.

scholarly journals Особенности регистрации спектра ядерного магнитного резонанса конденсированной среды при экспресс-контроле ее состояния

2020 ◽  
Vol 128 (10) ◽  
pp. 1554
Author(s):  
В.В. Давыдов ◽  
А.В. Мороз ◽  
Н.С. Мязин ◽  
С.С. Макеев ◽  
В.И. Дудкин
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Weak Magnetic Field ◽  
Experimental Studies ◽  
Condensed Medium ◽  
Weak Field ◽  
Nmr Spectrum ◽  
Nuclear Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The necessity of recording the spectrum of nuclear magnetic resonance in a weak field from a condensed medium during express control of its state is substantiated. The conditions are established that allow realizing the registration of nuclear magnetic resonance spectra in a weak field. A new design of a small-sized nuclear magnetic spectrometer has been developed for recording the NMR spectrum in a weak magnetic field from the volume of the condensed medium of the order of 3.0 ml. The results of experimental studies of various environments are presented.

scholarly journals In vivo Studies of Energy Metabolism in Experimental Cerebral Ischemia Using Topical Magnetic Resonance. Changes in 31P-Nuclear Magnetic Resonance Spectra Compared with Electroencephalograms and Regional Cerebral Blood Flow

1985 ◽  
Vol 5 (2) ◽  
pp. 235-240 ◽  
Author(s):  
Y. Horikawa ◽  
S. Naruse ◽  
K. Hirakawa ◽  
C. Tanaka ◽  
H. Nishikawa ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cerebral Ischemia ◽  
Magnetic Resonance ◽  
Energy State ◽  
In Vivo Studies ◽  
Nmr Spectrum ◽  
In Vivo Measurement ◽  
Nuclear Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The energy state of the brain during and after transient cerebral ischemia was examined in rats by in vivo measurement of 31P-nuclear magnetic resonance (NMR) spectra using a topical magnetic resonance spectrometer. EEGs and regional CBF (rCBF) were monitored on the same ischemic models. Immediately after the induction of ischemia, the height of the ATP and phosphocreatine peaks in the spectrum began to decrease with a concurrent increase of the inorganic phosphate (Pi) peak. The calculated pH from the chemical shift of Pi decreased during ischemia. The EEG pattern became flat immediately after ischemic induction. The rCBF decreased below the sensitivity level of the measuring instrument. With 30-min ischemia, the 31P-NMR spectrum returned to a normal pattern rapidly after recirculation. However, recovery of the EEG was delayed. The rCBF after recirculation showed postischemic hyperemia followed by hypoperfusion. In cases of 120-min ischemia, none of the spectra showed recovery. Thus, we could investigate the dynamic process of pathophysiological changes occurring in the ischemic brain in vivo.

Nuclear magnetic resonance microscopy

1989 ◽  
Vol 47 ◽  
pp. 828-829
Author(s):  
Paul C. Lauterbur
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Signal To Noise ◽  
Field Gradients ◽  
Useful Signal ◽  
Magnetic Field Gradients ◽  
Observation Times ◽  
Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

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