{TAIL ~ a source} of energy sufficient to heat tissue to form {HEAD ~ a denatured proteinaceous substance}; and 
{ TAIL ~ a source } of energy sufficient to heat tissue to form { HEAD ~ a denatured proteinaceous substance } ; and
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH