In {HEAD ~ certain preferred embodiments}, {TAIL ~ the molar ration} of : is in the range of 1:2 to 1:20 
In { HEAD ~ certain preferred embodiments } , { TAIL ~ the molar ration } of : is in the range of 1:2 to 1:20
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH