[1] MRC,RADIOBIOL UNIT,DIDCOT OX11 ORD,OXON,ENGLAND
[2] INST CANC RES,DEPT PHYS,SUTTON SM2 5PX,SURREY,ENGLAND
[3] UNIV LONDON IMPERIAL COLL SCI & TECHNOL,DEPT CHEM,LONDON SW7 2AZ,ENGLAND
[4] HATFIELD POLYTECH,DEPT CHEM,HATFIELD AL10 9AB,HERTS,ENGLAND