What is NUS acquisition?
Non-Uniform Sampling (NUS) has emerged as a very powerful tool to significantly speed up the acquisition of multidimensional NMR experiments.
This is due to the fact that only a subset of the usual linearly sampled data in the Nyquist grid is measured.
Why is NUS processing required?
This fast acquisition modality introduces a new challenge as the normal Fourier Transform will fail and consequently, special processing techniques are required.
A number of sophisticated methods have been proposed for reconstructing sparsely sampled 2D and higher dimensionality NMR data. Most of these procedures are computationally very expensive and usually require the adjustment of some parameters.
What has Mestrelab implemented since 2014?
Mestrelab has implemented within Mnova a new 2D NUS processing module that fulfills the following criteria:
- Computationally very fast whilst reconstructing the data reliably.
- Works fully automatically without user intervention. A minimum set of adjustable parameters might be used for special cases.
- Compatible with any 2D acquisition protocol and with NMR instrument.
All these requirements have been met with the development of M.I.S.T (MIST), a Modified Iterative Soft Threshold algorithm.
MIST in action: 2D NUS Processing
- The performance of the algorithm is demonstrated with the HSQC spectrum (example on the sidebar).
- Processing of the NUS spectrum was done fully automatically (just drag & drop into Mnova).
- Total processing time was less than 10 seconds.
- It performs well on other 2D experiments such as HMBC and COSY.
NUS 2D processing also for your Mnova app for tablet devices
NUS 2D processing has also been implemented on Mnova Tablet app facilitating the same fast processing on your mobile device for any non-uniform sampled (NUS) NMR spectra.
If you wish to know how to download Mnova Tablet app click here.
Linearly sampled HSQC spectrum
(96 complex increments).
MIST reconstruction of a NUS spectrum
acquired with 48 complex increments
The two figures are shown using
the same contour levels.