Source:http://linkedlifedata.com/resource/umls/id/C0439239
NCI: A basic unit of thermodynamic temperature, one of the seven base units of the International System of Units (Systeme International d'Unites, SI). It is 1/273.16th of the thermodynamic temperature of the triple point of water, This sets the size of the kelvin unit for temperature differences and defines the thermodynamic temperature of an equilibrium mixture of waters ice-liquid-vapor as 273.16 K, where 0 K is the lowest possible temperature ("absolute zero").