A Truncated Herpes Simplex Virus Thymidine Kinase Phosphorylates Thymidine and Nucleoside Analogs an

A closure structure for a container having end closures, one of the end closures being arranged to facilitate opening by a conventional type cutter, the closure being characterized by a diaphragm having an annular area therein with a thickness less than the thickness of the closure material, so that the annular area may be readily pierced and severed.