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Insensitive nuclei enhancement by polarization transfer (INEPT) is a signal enhancement method used in NMR spectroscopy. It involves the transfer of nuclear spin polarization from spins with large Boltzmann population differences to nuclear spins of interest with lower Boltzmann population differences. [ 1 ]
The linewidth is optimized for polarization transfer from electrons to nuclei, when it is close to the nuclear Larmor frequency. The optimization is related to an embedded three-spin (electron-electron-nucleus) process that mutually flips the coupled three spins under the energy conservation (mainly) of the Zeeman interactions.
A neuron receives signals from neighboring cells through branched, cellular extensions called dendrites.The neuron then propagates an electrical signal down a specialized axon extension from the basal pole to the synapse, where neurotransmitters are released to propagate the signal to another neuron or effector cell (e.g., muscle or gland).
Graphical representation of the INEPT NMR pulse sequence. INEPT is utilized often to improve 15 N resolution because it can accommodate negative gyromagnetic ratios, increases Boltzmann polarization, and decreases T 1 relaxation. [3] Insensitive nuclei enhanced by polarization transfer (INEPT) is a signal
Vector and tensor polarization of particle/nuclei with spin S ≥ 1 are specified by the unit polarization vector and the polarization tensor P `. Additional tensors composed of products of three or more spin matrices are needed only for the exhaustive description of polarization of particles/nuclei with spin S ≥ 3 ⁄ 2.
The nuclear Overhauser effect (NOE) is the transfer of nuclear spin polarization from one population of spin-active nuclei (e.g. 1 H, 13 C, 15 N etc.) to another via cross-relaxation.
A more specific example of this case is presented in the section Chemical Exchange Magnetization transfer. In either case, magnetization transfer techniques probe the dynamic relationship between two or more distinguishable nuclei populations, in so far as energy exchange between the populations can be induced and measured in an idealized NMR ...
Magnetization is then transferred from the proton to the heteronucleus through a one-bond scalar coupling (J-coupling), ensuring that only directly bonded nuclei participate in the transfer. Subsequently, the system evolves during a period called t 1 , and the magnetization is transferred back from the heteronuclear to the proton.