Structure-activity study of the inhibition of microtubule assembly in vitro by podophyllotoxin and its congeners.

Abstract

We obtain lower bounds for the size of a double blocking set in the Desarguesian projective planePG(2,q). These bounds are best possible forq<11 and in the caseqis a square. With the same technique we also exclude certain values for the size of an ordinary minimal blocking set.