Nuclear spin hyperpolarization is an important resource for increasing the sensitivity of NMR spectroscopy and MRI. Signal enhancements can be as large as 3–4 orders of magnitude. In hyperpolarization experiments, it is often desirable to transfer the initial polarization to other nuclei of choice, either protons or insensitive nuclei such as 13C and 15N. This situation arises primarily in Chemically Induced Dynamic Nuclear Polarization (CIDNP), Para-Hydrogen Induced Polarization (PHIP), and the related Signal Amplification By Reversible Exchange (SABRE). Here we review the recent literature on polarization transfer mechanisms, in particular focusing on the role of Level Anti-Crossings (LACs) therein. So-called “spontaneous” polarization transfer may occur both at low and high magnetic fields. In addition, transfer of spin polarization can be accomplished by using especially designed pulse sequences. It is now clear that at low field spontaneous polarization transfer is primarily due to coherent spin-state mixing under strong coupling conditions. However, thus far the important role of LACs in this process has not received much attention. At high magnetic field, polarization may be transferred by cross-relaxation effects. Another promising high-field technique is to generate the strong coupling condition by spin locking using strong radio-frequency fields. Here, an analysis of polarization transfer in terms of LACs in the rotating frame is very useful to predict which spin orders are transferred depending on the strength and frequency of the B1 field. Finally, we will examine the role of strong coupling and LACs in magnetic-field dependent nuclear spin relaxation and the related topic of long-lived spin-states.
Room temperature hyperpolarization of nuclear spins in bulk
From The DNP-NMR Blog:
Room temperature hyperpolarization of nuclear spins in bulk
Tateishi, K., et al., Room temperature hyperpolarization of nuclear spins in bulk. Proc. Nat. Aca. Sci. USA, 2014. 111(21): p. 7527-7530.
http://www.pnas.org/content/111/21/7527.abstract
Dynamic nuclear polarization (DNP), a means of transferring spin polarization from electrons to nuclei, can enhance the nuclear spin polarization (hence the NMR sensitivity) in bulk materials at most 660 times for 1H spins, using electron spins in thermal equilibrium as polarizing agents. By using electron spins...
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07-12-2014 04:28 AM
Spin dynamic simulations of solid effect DNP: the role of the relaxation superoperator
From The DNP-NMR Blog:
Spin dynamic simulations of solid effect DNP: the role of the relaxation superoperator
Karabanov, A., G. Kwiatkowski, and W. Köckenberger, Spin dynamic simulations of solid effect DNP: the role of the relaxation superoperator. Mol. Phys., 2014: p. 1-17.
http://dx.doi.org/10.1080/00268976.2014.884287
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07-09-2014 05:07 PM
Role of Electron Spin Dynamics on Solid-State Dynamic Nuclear Polarization Performance
From The DNP-NMR Blog:
Role of Electron Spin Dynamics on Solid-State Dynamic Nuclear Polarization Performance
Siaw, T.A., et al., Role of Electron Spin Dynamics on Solid-State Dynamic Nuclear Polarization Performance. Phys. Chem. Chem. Phys., 2014.
http://dx.doi.org/10.1039/C4CP02013H
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06-20-2014 08:14 PM
Level Anti-Crossings are a Key Factor for Understanding para-Hydrogen-Induced Hyperpolarization in SABRE Experiments
From The DNP-NMR Blog:
Level Anti-Crossings are a Key Factor for Understanding para-Hydrogen-Induced Hyperpolarization in SABRE Experiments
Pravdivtsev, A.N., et al., Level Anti-Crossings are a Key Factor for Understanding para-Hydrogen-Induced Hyperpolarization in SABRE Experiments. ChemPhysChem, 2013. 14(14): p. 3327-3331.
http://www.ncbi.nlm.nih.gov/pubmed/23959909
Level anti-crossings in ParaHydrogen Induced Polarization experiments with Cs-symmetric molecules
From The DNP-NMR Blog:
Level anti-crossings in ParaHydrogen Induced Polarization experiments with Cs-symmetric molecules
Buljubasich, L., et al., Level anti-crossings in ParaHydrogen Induced Polarization experiments with Cs-symmetric molecules. J Magn Reson, 2012. 219(0): p. 33-40.
http://www.ncbi.nlm.nih.gov/pubmed/22595295
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11-21-2013 01:14 AM
Dynamic Nuclear Hyperpolarization in Liquids
From The DNP-NMR Blog:
Dynamic Nuclear Hyperpolarization in Liquids
Günther, U., Dynamic Nuclear Hyperpolarization in Liquids, in Modern NMR Methodology, H. Heise and S. Matthews, Editors. 2013, Springer Berlin Heidelberg. p. 23-69.
http://dx.doi.org/10.1007/128_2011_229
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07-18-2013 12:39 AM
Structure and lipid interactions of an anti-inflammatory and anti-atherogenic 10-residue class G(*) apolipoprotein J peptide using solution NMR.
Structure and lipid interactions of an anti-inflammatory and anti-atherogenic 10-residue class G(*) apolipoprotein J peptide using solution NMR.
Structure and lipid interactions of an anti-inflammatory and anti-atherogenic 10-residue class G(*) apolipoprotein J peptide using solution NMR.
Biochim Biophys Acta. 2011 Jan;1808(1):498-507
Authors: Mishra VK, Palgunachari MN, Hudson JS, Shin R, Keenum TD, Krishna NR, Anantharamaiah GM
The surprising observation that a 10-residue class G(?) peptide from apolipoprotein J, apoJ, possesses...
The role of level anti-crossings in nuclear spin hyperpolarization
Linear Mode
