An Image-Based Website User Authentication Mechanism Using Smart Card

A monocyclic beta -lactam antibiotic having a formamido substituent at the 3S-position, including compounds of the formula (I): (I) and salts thereof wherein R is -SO3H; -PO(OH)Y wherein Y is C1-6 alkoxy, hydroxy, aryloxy, C1-6 alkyl or aryl; wherein Z represents C1-6 alkyl or aryl; wherein Z1 and Z2 may be the same or different and each represents hydrogen, C1-6 alkyl, aryl, amino or C1-6 alkoxy, or Z1 and Z2 together form the residue of a heterocyclic ring; -OSO3H; or where X is hydrogen or hydroxy; R1 is an amino, protected amino or carboxylic acylamino group, and R2 and R3 are independently selected from hydrogen or a hydrocarbon group of 1 to 18 carbon atoms.