The present invention relates generally to synthetic pyrimidine derivatives and, more particularly, to the methods of deriving the compounds that are the derivatives of 2,8-dithioxo-1H-pyrano2,3-d: 6,5-d\u2032dipyrimidine or its 10-aza-analogue. In one embodiment, each tip has an overcap with an antimicrobial sponge disposed therein, the sponge sanitizing the writing tip when not in use. The retention portion is provided so as to be in contact with the heat-generating body of the radiographic detector, detachably retains a power supply portion, and is thermally conductive. A stator is positioned opposite a rotor. The invention also relates to RGD-enriched gelatines that are used for attachment to integrins.