Transverse relaxation time T2 and the corresponding proton
density was measured by a 0.3 T 1HYOMINGMR2 NMR spectrometer
(Ningbo, Zhejiang, China) and calculated using a CPMG pulse
sequence, in which the number of sampling points (TD) was
16,384, Echo Time (TE) was 14 ms, while the number of echo
(NE) was 300.