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Showing 1 to 20 of 68 for “"dynamic nuclear polarization"”.
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Coherent Dynamic Nuclear Polarization: Mechanistic Insights and Experimental Advances
Dynamic Nuclear Polarization (DNP) enhances the sensitivity of solid-state Nuclear Magnetic Resonance (NMR) by transferring polarization from electrons to nuclei. While traditional continuous-wave (CW) DNP has advanced through improved radical design, the development of pulsed DNP—employing short, …
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Dynamic nuclear polarization of amorphous and crystalline small molecules
… pharmaceutical ingredients (API) and excipients. Dynamic nuclear polarization (DNP), which improves NMR sensitivity by 2-3 orders of magnitude, can potentially reduce the necessary experimental time for formulations that have low API contents. However, conventionally DNP samples are prepared in …
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Dynamic nuclear polarization for NMR : applications and hardware development
… as well as supermolecular structure and dynamics. The low signal intensities make many of these experiments prohibitively long. Dynamic Nuclear Polarization provides a method of enhancing signal intensities and reducing experimental time. DNP requires transferring polarization from …
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Dynamic Nuclear Polarization in Samarium Doped Lanthanum Magnesium Nitrate
The dynamic nuclear polarization of hydrogen nuclei by the solid effect in single crystals of samarium doped lanthanum magnesium nitrate (Sm:LMN) has been studied theoretically and experimentally. The equations of evolution governing the dynamic nuclear polarization by the solid effect have been …
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Dynamic nuclear polarization of biological systems at high magnetic fields
Dynamic nuclear polarization methods were studied at high magnetic field strength and were applied to improve the sensitivity of the nuclear magnetic resonance spectroscopy of biological solids. Studies of the dynamics of electron-nuclear polarization transfer via the solid effect and thermal …
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High field dynamic nuclear polarization methods: Microwave sources and mechanisms
In thirty years of active development, dynamic nuclear polarization (DNP) has emerged as a forefront technique for expanding the scope of solid state nuclear magnetic resonance. For the most part, and particularly at high fields, these advances have come with continuous-wave microwave irradiation …
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Advances in Instrumentation for Dynamic Nuclear Polarization & Magic-Angle Spinning NMR
Dynamic nuclear polarization (DNP) is an invaluable tool for increasing the sensitivity of magic angle spinning (MAS) nuclear magnetic resonance (NMR) experiments. Historically, one of the primary drawbacks of DNP has been limited spectral resolution. The resolution of DNP spectra can be …
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Polarizing agents for high-frequency Dynamic Nuclear Polarization : development and applications
Dynamic Nuclear Polarization (DNP) is utilized to enhance NMR signal intensities in systems including metals, ceramics, polymers and biological solids. The enhancement results from polarization transfers from unpaired electrons, usually carried by a polarizing agent such as TEMPO …
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LC - ¹³C NMR utilizing dynamic nuclear polarization (DNP) for signal enhancement
… this requirement, our laboratory has utilized dynamic nuclear polarization (DNP) to ameliorate these otherwise weak or non-existent signals. For favorable molecules, sensitivity recoveries of up to two orders of magnitude have been developed. This improvement (relative to 'H) narrows the …
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I. Persistent radicals for dynamic nuclear polarization : II. Synthesis of substituted indoles
Part I: An brief introduction to dynamic nuclear polarization (DNP) is provided including a discussion of polarization mechanisms and development of new polarization methods in a historical context. Efficient synthesis of highly water-soluble BDPA derivatives that preserve the desirable DNP …
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High-resolution high-frequency dynamic nuclear polarization for biomolecular solid state NMR
Dynamic Nuclear Polarization (DNP) has exploded in popularity over the last few years, finally realizing its potential to overcome the detrimental lack of sensitivity that has plagued performing NMR experiments. Applied to magic angle spinning (MAS) experiments, this renaissance of DNP has been …
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Liquid Phase Carbon-Thirteen Dynamic Nuclear Polarization Study of Monosubstituted Aromatic Compounds
… This suggests that facile transfer of spin polarization to the C-1 carbon via the highly polarizable iodine atom is possible and the dominate electron transfer mechanism for this system. A model of polarization transfer via spin diffusion of abundant proton spins was examined. The results …
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Dynamic nuclear polarization and electron spin resonance in paramagnetic solids at high field
Recent advances in high resolution solid state nuclear magnetic resonance spectroscopy have permitted the detailed structural study of large biological systems. The feasibility of many of these experiments is limited by the inherently low sensitivity of solid state NMR, and the implementation of …
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Flow 1H Dynamic Nuclear Polarization Studies in Normal Liquids and Supercritical Fluid Carbon Dioxide
Flow 1H dynamic nuclear polarization (DNP) experiments of small probe molecules (i.e. chloroform and benzene) were conducted in normal liquids (i.e. neat benzene, deuterated benzene, chloroform) and supercritical fluid CO₂. Initial data collected on the 14N NMR line width of acetonitrile in normal …
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High resolution ¹H, ²D, ¹³C, ²⁹Si, and ¹⁵N dynamic nuclear polarization: development and applications
The limitations of previous dynamic nuclear polarization (DNP) experiments have been avoided by a transfer DNP approach whereby the nuclear spins are polarized by DNP at low magnetic field (0.33 T) and then quickly transferred to a high monitoring field (4.7 T). This approach provides an order of …
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Design, synthesis, and characterization of conjugated polymers and functional paramagnetic materials for dynamic nuclear polarization
… a series of radicals and biradicals for use as dynamic nuclear polarization (DNP) agents is described. DNP is a method to enhance the S/N-ratio in solid-state nuclear magnetic resonance (SS-NMR) that involves transferring the polarization of electrons, which are more easily polarized due to …
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Elucidating the pumping mechanism of bacteriorhodopsin using dynamic nuclear polarization enhanced magic angle spinning NMR
… in sensitivity and/or resolution. Here, dynamic nuclear polarization (DNP) is employed to boost the ¹H NMR signal. With an enhancement of 75, multidimensional spectra of low gyromagnetic nuclei were made possible. The cryogenic experimental temperature also traps the various bR photocycle …
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Advances in Sensitivity and Resolution of Solid State Nuclear Magnetic Resonance and Dynamic Nuclear Polarization
… such as x-ray crystallography and solution-state nuclear magnetic resonance (NMR) cannot provide atomic level resolution of insoluble, noncrystalline proteins. Such proteins include amyloid fibrils implicated in numerous neurodegenerative diseases. While solid state NMR using magic angle spinning …
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Design of a 460 GHz second harmonic gyrotron oscillator for use in dynamic nuclear polarization
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.
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