摘要:
                                N-15-Choline-d(13) was synthesized as a new biomarker for dynamic nuclear polarization, and the lifetime of the polarized signal governed by the spin-lattice relaxation time T-1 was measured. N-15-Choline-d(13) exhibited a T-1 that was over twice as long as that of N-15-choline, and the hyperpolarized N-15 signal could be observed for 1 h. (C) 2013 Elsevier Ltd. All rights reserved.