1. Centre for Magnetic Resonance, and Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St. Lucia, Queensland 4072, Australia, School of Physical Sciences, Queensland University of Technology, Brisbane, Queensland, 4001, Australia, School of Molecular and Microbial Science, University of Queensland, St. Lucia, Queensland 4072, Australia, and SEMATECH, Austin, Texas 78741-6499