Encoding resonance

Magnetic resonance unaging, flow and diflfiision all rely upon manipulating spatially varying magnetic fields in such a maimer as to encode spatial infonnation within the accumulated precession of the magnetization. In... 

A. G. Webb 2004, (Optimizing the point spread function in phase-encoded magnetic resonance microscopy), Concept Magn. Reson. 22A, 25-36. 

Pure Phase Encode Magnetic Resonance Imaging of Concrete Building Materials 285 3.4... 

Y. Xia, P.T. Callaghan 1992, ( One-shot velocity microscopy NMR imaging of motion using a single phase-encoding step), Magn. Reson. Med. 23 (1), 138-153. 

S. Han, S. Stapf, B. Bliimich 2000, (Two-dimensional PFG-NMR for encoding correlations of position, velocity and acceleration in fluid transport), J. Magn. Reson. 146, 169. 

Fluorescence or Forster resonance energy transfer (FRET) is widely accepted as being one of the most useful methods to observe biochemical events in vitro and in living cells. Generally, there are two forms of FRET sensors those based on a pair of genetically encoded fluorophores, usually employing fluorescent proteins from jellyfish or corals, or those based on small molecules that make use of small organic fluorophores. 

Fehr, M., Takanaga, H., Ehrhardt, D. W. and Frommer, W. B. (2005b). Evidence for high-capacity bidirectional glucose transport across the endoplasmic reticulum membrane by genetically encoded fluorescence resonance energy transfer nanosensors. Mol. Cell. Biol. 25, 11102-12. 

The REDOR experiment has formed the basis for a large number of ideal pulse type recoupling experiments, and later finite pulse variants, for heteronuclear dipolar recoupling. These include experiments such as frequency selective REDOR (FS-REDOR) [80], TEDOR (Transferred Echo DOuble Resonance) [25], and 3D variants of TEDOR [81, 82], which have found important applications, e.g., for measurement of intemuclear 13C-15N distances in biological solids. We should also mention that rotor-encoded variants of TEDOR, such as REPT, HDOR [83], and REREDOR [84], have been proposed for 1H13C dipolar recoupling under high-speed MAS conditions. 

One should note that the phase shift becomes time-independent and maximal for a = 1, i.e., at the resonance condition v = vG. The frequency spectrum 4>(a) bears a sine shape with a bandwidth inversely proportional to the number of oscillations of the gradient field (Fig. 4). Such a behaviour was also predicted in Ref. 15. Recording in a systematic way the phase shift as a function of vG without space encoding would be a very fast and efficient method to scan in a whole object the possible frequencies of spin motions. 

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