1. Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K., Turku PET Centre, University of Turku and Åbo Akademi University, Kiinamyllynkatu 4-8, 20520 Finland, Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, U.K., GE Healthcare, The Grove Centre, White Lion Road, Amersham HP7 9LL. U.K., AstraZeneca, Etherow Building, Silk Road Business Park, Macclesfield, Cheshire SK10 2NA, U.K., and Imanova, Burlington Danes Building, Imperial College London,...