The<unk>  in diagnostic radiology, is the conversion<unk>  between exposure and absorbed dose. In other words, it converts between the amount of ionization in air (roentgens or, in SI units, coulombs per kilogram of absorber material) and the absorbed dose in air (rads or grays). The two determinants of the<unk> are the effective atomic number (Z) of the material and the type of ionizing radiation being considered. Since the effective Z of air and soft tissue is approximately the same, the<unk> is approximately 1 for many x-ray imaging applications. However, bone has an<unk> of up to 4, due to its higher effective Z.
F-factor 
Fibrinolysin
Protoxin-II
M protein 
PULHES Factor
Transfer factor
C1-inhibitor
Α-Hederin