Filibian, M., et al., Nuclear magnetic resonance studies of DNP-ready trehalose obtained by solid state mechanochemical amorphization. Phys Chem Chem Phys, 2016. 18(25): p. 16912-20.
(1)H nuclear spin-lattice relaxation and Dynamic Nuclear Polarization (DNP) have been studied in amorphous samples of trehalose sugar doped with TEMPO radicals by means of mechanical milling, in the 1.6-4.2 K temperature range. The radical concentration was varied between 0.34 and 0.81%. The highest polarization of 15% at 1.6 K, observed in the sample with concentration 0.50%, is of the same order of magnitude of that reported in standard frozen solutions with TEMPO. The temperature and concentration dependence of the spin-lattice relaxation rate 1/T1, dominated by the coupling with the electron spins, were found to follow power laws with an exponent close to 3 in all samples. The observed proportionality between 1/T1 and the polarization rate 1/Tpol, with a coefficient related to the electron polarization, is consistent with the presence of Thermal Mixing (TM) and a good contact between the nuclear and the electron spins. At high electron concentration additional relaxation channels causing a decrease in the nuclear polarization must be considered. These results provide further support for a more extensive use of amorphous DNP-ready samples, obtained by means of comilling, in dissolution DNP experiments and possibly for in vivo metabolic imaging.
Dynamic Nuclear Polarization as an Enabling Technology for Solid State Nuclear Magnetic Resonance Spectroscopy
From The DNP-NMR Blog:
Dynamic Nuclear Polarization as an Enabling Technology for Solid State Nuclear Magnetic Resonance Spectroscopy
Smith, A.N. and J.R. Long, Dynamic Nuclear Polarization as an Enabling Technology for Solid State Nuclear Magnetic Resonance Spectroscopy. Analytical Chemistry, 2016. 88(1): p. 122-132.
http://dx.doi.org/10.1021/acs.analchem.5b04376
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02-01-2016 05:12 PM
Dynamic nuclear polarization of a glassy matrix prepared by solid state mechanochemical amorphization of crystalline substances
From The DNP-NMR Blog:
Dynamic nuclear polarization of a glassy matrix prepared by solid state mechanochemical amorphization of crystalline substances
Elisei, E., et al., Dynamic nuclear polarization of a glassy matrix prepared by solid state mechanochemical amorphization of crystalline substances. Chem Commun (Camb), 2015. 51(11): p. 2080-3.
http://www.ncbi.nlm.nih.gov/pubmed/25534192
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04-09-2015 03:47 AM
Dynamic nuclear polarization of a glassy matrix prepared by solid state mechanochemical amorphization of crystalline substances
From The DNP-NMR Blog:
Dynamic nuclear polarization of a glassy matrix prepared by solid state mechanochemical amorphization of crystalline substances
This is a very interesting article describing the preparation of a sample for DNP by co-milling the analyte with the polarizing substrate. For a long time it was thought that just mechanically mixing the polarizing agent with the analyte will not result in a sample that is useful for DNP because the radical has to be mixed at an atomic level. Clearly this article demonstrate that this is not necessary. This will open up DNP to be used...
Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25K
Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25K
January 2013
Publication year: 2013
Source:Journal of Magnetic Resonance, Volume 226</br>
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We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20–25K and 9.4Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier , but also includes a corrugated waveguide for transmission of microwaves from...
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12-15-2012 09:51 AM
Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K
Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K
Publication year: 2012
Source:Journal of Magnetic Resonance</br>
Kent R. Thurber, Alexey Potapov, Wai-Ming Yau, Robert Tycko</br>
We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20-25 K and 9.4 Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier (Thurber et al., J. Magn. Reson. 2008) ,...
Nuclear magnetic resonance studies of DNP-ready trehalose obtained by solid state mechanochemical amorphization #DNPNMR
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