There are multiple definitions:

1. 2,4-dinitrophenyl(English)

   • can be used to qualitatively detect the carbonyl functionality of a ketone or aldehyde functional group
   • Biochemistry
   • http://myweb.li…he122/exp13.pdf

2. dynamic nuclear polarization(English)

   • NMR, PHIP
   • Biophysics, Medical imaging
   • https://doi.org…cs.jpcc.7b12069