Examples of active agents include a paramagnetic element, a radioactive element and {HEAD ~ a fibrinolytic agent}, among {TAIL ~ others} 
among
Examples of active agents include a paramagnetic element , a radioactive element and { HEAD ~ a fibrinolytic agent } , among { TAIL ~ others }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL