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Priority claimed from US07/089,073external-prioritypatent/US4839464A/en
Priority claimed from US07/225,045external-prioritypatent/US5019646A/en
Application filed by Univ MinnesotafiledCriticalUniv Minnesota
Application grantedgrantedCritical
Publication of ATE87936T1publicationCriticalpatent/ATE87936T1/en