To correct for differential relaxation, an inversion recovery experiment using an array of delay times from 0 to 10 s was performed on both medium and cell extracts.
TR, relaxation time, TI, inversion time, TE, echo time, IR, inversion recovery, mm, millimetre, ms, millisecond, SPIR, spectral presaturation with inversion recovery, FLAIR, fluid attenuated inversion recovery.
Such a relatively large error floor was chosen to roughly represent the estimated data accuracy, which was not available, and to provide a sort of relaxation in the inversion.
The nonexponential shape of IR curves is usually attributed to a contribution from spectral diffusion that often obscures intrinsic longitudinal relaxation rates determined from inversion recovery (35, 44).
By combining the three inversions, the relaxation curve is sampled in an interleaved manner, resulting in a sufficient number of points for accurate T1 quantification (Fig. 6) [10].
This is particularly due to, the p-orbital moments of Te contributing, vectorially, to spin relaxation process operative at broken inversion symmetry sites.
This is illustrated in Fig. 1, where both the relaxation of the magnetisation after inversion and the signal after excitation are shown.
Also, T1 and T2 relaxation times were determined using an inversion recovery (IR) true-FISP sequence (TI=109 2902 ms, 25 inversion times, TR=2.4 ms, TE=1.2 ms, eight averages, scan TR=10 s), and the data fitted using a similar a posteriori approach but which also utilised the dual relaxation sensitivity of the IR true-FISP sequence (Walker-Samuel et al, 2009).
Combining The appropriaterelaxationumber cofstant with the porelaxation marrangementrove the accuracy of determining the pointsbinity overelaxationtal porosity from core measurements.
13C-T1 relaxatimestimes were determined by the inversion recovery method for all carbons to ensure conditions for quantitative 13C NMR measurements.
