Hyperpolarized Amino Acid Derivatives as Multivalent Magnetic Resonance pH Sensor Molecules. - Christian Hundshammer; Stephan Düwel; David Ruseckas; Geoffrey Topping; Piotr Dzien; Christoph Müller; Benedikt Feuerecker; Jan B. Hövener; Axel Haase; Markus Schwaiger; Steffen J. Glaser; Franz Schilling (Sensors, 2018)