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Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
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Dynamic nuclear polarization studies on deuterated nitroxyl spin probes
D David Jebaraj1, Hideo Utsumi2, A Milton Franklin Benial3
1Department of Physics, The American College, Madurai, 625 002, Tamil Nadu, India.
Magnetic Resonance in Chemistry : MRC
|April 27, 2017
Summary
Deuterated nitroxyl radicals enhance Overhauser-enhanced magnetic resonance imaging (MRI) more than undeuterated versions. These studies clarify dynamic nuclear polarization (DNP) parameters crucial for improved MRI contrast agents.
Area of Science:
- Magnetic Resonance Spectroscopy
- Medical Imaging
- Chemical Physics
Background:
- Nitroxyl radicals are vital for Overhauser-enhanced magnetic resonance imaging (MRI).
- Understanding dynamic nuclear polarization (DNP) parameters is key to optimizing MRI contrast agents.
Purpose of the Study:
- To investigate the DNP and electron spin resonance (ESR) properties of novel nitroxyl radicals and their deuterated counterparts.
- To evaluate the potential of these radicals as contrast agents in Overhauser-enhanced MRI.
Main Methods:
- Detailed dynamic nuclear polarization (DNP) and electron spin resonance (ESR) studies.
- Estimation of DNP parameters: DNP factor, longitudinal relaxivity, saturation parameter, leakage factor, and coupling factor.
- Calculation of ESR parameters: line width, line shape, rotational correlation time, hyperfine coupling constant, and g-factor.
Main Results:
- Deuterated nitroxyl radicals exhibited higher DNP enhancement compared to undeuterated versions due to narrower line widths.
- DNP enhancement increased with agent concentration up to 3 mM, then decreased.
- The coupling parameter indicated a predominantly dipolar interaction between electron and nuclear spins.
Conclusions:
- Deuterated nitroxyl radicals offer superior performance for Overhauser-enhanced MRI.
- The study provides a clear understanding of DNP parameters influencing MRI contrast.
- These findings pave the way for developing more effective MRI contrast agents.
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