Thus, the nanoscale particles may comprise a metal or {HEAD ~ a metal oxide} such as {TAIL ~ iron oxide} 
such as
Thus , the nanoscale particles may comprise a metal or { HEAD ~ a metal oxide } such as { TAIL ~ iron oxide }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL