1. Medical School, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, U.K.
2. Centre for Mass Spectrometry Imaging, Biomolecular Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, U.K.
3. Materials Research and Technology, Luxembourg Institute of Science and Technology, Belvaux L-4422, Luxembourg
4. European Application Laboratory, Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, U.K.
5. Departments of Pediatrics and Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
6. Department of Chemistry and Laboratory of Integrated Neuroscience, University of Illinois at Chicago, Chicago, Illinois 60607, United States