{HEAD ~ The typical particle size} is from about 0.7 to about 0.8 micrometers in {TAIL ~ mean diameter} 
{ HEAD ~ The typical particle size } is from about 0.7 to about 0.8 micrometers in { TAIL ~ mean diameter }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL