NCIt definition : A SI derived unit of activity of a radionuclide, equal to one nuclear disintegration
or other nuclear transition from a particular energy state occurring in an amount
of a radionuclide during one second-long time interval.;
Alternative definition : CDISC: A unit of activity of a radionuclide, equal to one nuclear disintegration or
other nuclear transition from a particular energy state occurring in an amount of
a radionuclide during one second-long time interval.(NCI);