Analysis of the appearance and disappearance of members of the complex and of the cross linked substance provides a tool for evaluating {HEAD ~ components} of living systems and thereby to follow {TAIL ~ the effects} of treatments of, and abnormalities in, these systems 
Analysis of the appearance and disappearance of members of the complex and of the cross linked substance provides a tool for evaluating { HEAD ~ components } of living systems and thereby to follow { TAIL ~ the effects } of treatments of , and abnormalities in , these systems
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH