Previous works reported that the T1 relaxation values of liver methylene and methene groups were respectively between 0.39 to 1.20 s and 0.60 to 1.16 s [34, 35].
where [I.sub.methene], [I.sub.allylic], [I.sub.methylene], and [I.sub.methyl] are, respectively, the signal amplitude of the methene, allylic methylene, bulk methylene, and terminal methyl peaks.
UIs formula is based on the principle that methene functional group is always next to allylic methylene group in monounsaturated fatty acids and with both allylic and diallylic methylene groups in Poly Unsaturated Fatty Acids (PUFAs).
Table 1: Key Greenhouse Gases Affected by Human Activity (Percentage) Effect Carbon Nitrous dioxide
Methene CFC Oxide Increase in atmospheric concentrations Pre-industrial to 1990 26 115 -- 8 1990-2025 23 51 -- 10 Contribution to the change in heat trapping Pre-industrial to 1990 61 23 12 4 1990-2025 68 17 10 5 Source: World Development Report 1992.