Abstract: Antibacterial activity is exhibited by 2-azetidinones having a 3-acylamino substituent and having an activating group in the 1-position of the formula ##STR1## wherein R is ##STR2## A.sub.1 is --NH-- or ##STR3## A.sub.2 is ##STR4## or --CH.dbd.CH--.

Abstract: A rigid, hollow cylindrical insert is designed to be located and to remain in the end portion of a deformable plastic tube. The end portion of the tube is situated between thin film layers with the insert aligned with an edge to be sealed. The assembly is placed between the mating pressure dies to be welded. In a single operation, the edges of the layers are sealed to form a pouch as the tube end portion is welded to the layers along the seam at the top of the pouch. The insert supports the tube end portion in a non-deformed state during welding. This permits an effective weld to be obtained with tubes of various structures and, particularly, very soft tubes such as ones with thin walls composed of polyvinylchloride.