Vuichoud, B., et al., Hyperpolarization of deuterated metabolites via remote cross-polarization and dissolution dynamic nuclear polarization. J Phys Chem B, 2014. 118(5): p. 1411-5.
http://www.ncbi.nlm.nih.gov/pubmed/24397585
In deuterated molecules such as [1-(13)C]pyruvate-d3, the nuclear spin polarization of (13)C nuclei can be enhanced by combining Hartmann-Hahn cross-polarization (CP) at low temperatures (1.2 K) with dissolution dynamic nuclear polarization (D-DNP). The polarization is transferred from remote solvent protons to the (13)C spins of interest. This allows one not only to slightly reduce build-up times but also to increase polarization levels and extend the lifetimes T1((13)C) of the enhanced (13)C polarization during and after transfer from the polarizer to the NMR or MRI system. This extends time scales over which metabolic processes and chemical reactions can be monitored.