Broadband homonuclear TOCSY with amplitude and phase-modulated RF mixing schemes.
J Biomol NMR
; 40(4): 227-37, 2008 Apr.
Article
en En
| MEDLINE
| ID: mdl-18317934
ABSTRACT
We have explored the design of broadband scalar coupling mediated (13)C-(13)C and cross-relaxation suppressed (1)H-(1)H TOCSY sequences employing phase/amplitude modulated inversion pulses. Considering a variety of supercycles, pulsewidths and a RF field strength of 10 kHz, the Fourier coefficients defining the amplitude and phase modulation profiles of the 180 degrees pulses were optimised numerically so as to obtain efficient magnetisation transfer within the desired range of resonance offsets. The coherence transfer characteristics of the mixing schemes were assessed via numerical simulations and experimental measurements and were compared with commonly used sequences based on rectangular RF pulses. The efficacies of the clean (1)H-(1)H TOCSY sequences were also examined via numerical simulations for application to weakly oriented systems and sequences with efficient, broadband and clean dipolar transfer characteristics were identified. In general, the amplitude and phase modulated TOCSY sequences presented here have moderately better performance characteristics than the sequences currently employed in biomolecular NMR spectroscopy.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Espectroscopía de Resonancia Magnética
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Biomol NMR
Asunto de la revista:
BIOLOGIA MOLECULAR
/
DIAGNOSTICO POR IMAGEM
/
MEDICINA NUCLEAR
Año:
2008
Tipo del documento:
Article
País de afiliación:
Alemania