| 摘要 |
A compound for therapeutic or diagnostic use, characterized by having formula (I): wherein R1 and R2 independently are hydrogen, lower alkyl, acyl or together form a cyclic amide or amine; wherein R3 and R4 independently are hydrogen, alkyl, an organic residue; and wherein n is >=2, the individual monomer residues of the compound (I) being independ of each other as to structure; a composition containing such compound, methods for use of the compound and the composition, respectively. |
