Evolution time, constant

Powers R, Gronenborn AM, Clore GM, Bax A. Three-dimensional tripleresonance NMR of 13C/15N-enriched proteins using constant-time evolution. J Magn Reson 1991 94 209-213. 

D 1H-13C CT-HSQC/HMQC identifies proton-carbon spin pairs in both sugar and base. The constant time evolution removes the peak splitting due to 13C-13C coupling. The proton and carbon resonances are subsequently connected by... 

Here, is an Al-dimensional vector containing the transverse relaxation rates along all indirect dimensions, with R 2 = 0 for constant-time evolution elements in the dimension i. Since the standard GAPRO analysis attaches equal weight to each projection spectrum, it is desirable to have similar sensitivities for all individual projection experiments. If the projection angle-dependence of t) is known, (7) provides a basis for producing similar sensitivities for all the projections used in a given APSY experiment, since the user-defined parameters n (p), M (p), hm (p, t), and fmax(0) can be individually adjusted for each projection experiment [5, 42]. 

The approach of Furihata and Seto was to introduce a constant time evolution period in the CT-HMBC-1 pul.se sequence shown in Fig. 9(a). Thus, rather than a sequence in which evolution is represented by... 

Interpulse Low-pass Constant time Evolution Constant time Low-pass delay J filter variable delay variable delay J filter... 

Intra-residue selectivity have been introduced into the CANCO experiment to detect (C ,COi,Ni+i) correlations. The coherence transfer starts with C , converted into the double-anti-phase C zCOzNy coherence and subsequently refocused into the observable CO transverse magnetisation. Two variants of the experiment were described, that either achieved refocusing through the constant time evolution of N or used non-constant time period to detect the N evolution, followed by the refocusing through the transverse CO evolution. The choice of the optimal experiment depends on the relaxation rates of the nuclei. 

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