In {TAIL ~ certain preferred embodiments}, the molar ration of :{HEAD ~ A} is in the range of 1:1 to 1:10 
In { TAIL ~ certain preferred embodiments } , the molar ration of : { HEAD ~ A } is in the range of 1:1 to 1:10
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH