Santiago de Compostela, Spain
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Garcia-Figueiras R.,Hospital Clinico Universitario Of Santiago Of Compostela | Baleato-Gonzalez S.,Hospital Clinico Universitario Of Santiago Of Compostela | Padhani A.R.,Paul Strickland Scanner Center | Oleaga L.,Hospital Clinic Barcelona | And 4 more authors.
Diagnostic and Interventional Radiology | Year: 2016

Abnormal metabolism is a key tumor hallmark. Proton magnetic resonance spectroscopy (1H-MRS) allows measurement of metabolite concentration that can be utilized to characterize tumor metabolic changes. 1H-MRS measurements of specific metabolites have been implemented in the clinic. This article performs a systematic review of image acquisition and interpretation of 1H-MRS for cancer evaluation, evaluates its strengths and limitations, and correlates metabolite peaks at 1H-MRS with diagnostic and prognostic parameters of cancer in different tumor types. © Turkish Society of Radiology 2016.


Lewis R.J.,Astrazeneca | Bernstein M.A.,Astrazeneca | Bernstein M.A.,Mestrelab Research | Chang H.-F.,Astrazeneca | And 2 more authors.
Tetrahedron Asymmetry | Year: 2013

The NMR spectra of separate samples of an analyte complexed with each enantiomer of a chiral solvating agent (CSA) give an accurate estimate of the chemical shifts of racemic analytes in the presence of a single enantiomer of the CSA. This effect allows a CSA-based chiral NMR method to be developed when only a single enantiomer of analyte is available. The ability to develop a method capable of discriminating between enantiomers in these circumstances is useful, for example, to resolve the question of whether racemization has occurred during the synthesis of a chiral molecule. © 2013 Elsevier Ltd. All rights reserved.


Fredi A.,Autonomous University of Barcelona | Nolis P.,Autonomous University of Barcelona | Cobas C.,Mestrelab Research | Parella T.,Autonomous University of Barcelona
Journal of Magnetic Resonance | Year: 2016

Covariance processing is a versatile processing tool to generate synthetic NMR spectral representations without the need to acquire time-consuming experimental datasets. Here we show that even experimentally prohibited NMR spectra can be reconstructed by introducing key features of a reference 1D CHn-edited spectrum into standard 2D spectra. This general procedure is illustrated with the calculation of experimentally infeasible multiplicity-edited pure-shift NMR spectra of some very popular homonuclear (ME-psCOSY and ME-psTOCSY) and heteronuclear (ME-psHSQC-TOCSY and ME-psHMBC) experiments. © 2016 Elsevier Inc.


Fredi A.,Autonomous University of Barcelona | Nolis P.,Autonomous University of Barcelona | Cobas C.,Mestrelab Research | Martin G.E.,Merck And Co. | Parella T.,Autonomous University of Barcelona
Journal of Magnetic Resonance | Year: 2016

The current Pros and Cons of a processing protocol to generate pure chemical shift NMR spectra using Generalized Indirect Covariance are presented and discussed. The transformation of any standard 2D homonuclear and heteronuclear spectrum to its pure shift counterpart by using a reference DIAG spectrum is described. Reconstructed pure shift NMR spectra of NOESY, HSQC, HSQC-TOCSY and HSQMBC experiments are reported for the target molecule strychnine. © 2016 Elsevier Inc. All rights reserved.


Abraham R.J.,University of Liverpool | Griffiths L.,Astrazeneca | Perez M.,Mestrelab Research
Magnetic Resonance in Chemistry | Year: 2014

The 1H chemical shifts of 48 amides in DMSO solvent are assigned and presented. The solvent shifts Δδ (DMSO-CDCl3) are large (1-2 ppm) for the NH protons but smaller and negative (-0.1 to -0.2 ppm) for close range protons. A selection of the observed solvent shifts is compared with calculated shifts from the present model and from GIAO calculations. Those for the NH protons agree with both calculations, but other solvent shifts such as Δδ(CHO) are not well reproduced by the GIAO calculations.The 1H chemical shifts of the amides in DMSO were analysed using a functional approach for near ( ≤ 3 bonds removed) protons and the electric field, magnetic anisotropy and steric effect of the amide group for more distant protons. The chemical shifts of the NH protons of acetanilide and benzamide vary linearly with the π density on the αN and βC atoms, respectively. The C=O anisotropy and steric effect are in general little changed from the values in CDCl3. The effects of substituents F, Cl, Me on the NH proton shifts are reproduced. The electric field coefficient for the protons in DMSO is 90% of that in CDCl3. There is no steric effect of the C=O oxygen on the NH proton in an NH...O=C hydrogen bond. The observed deshielding is due to the electric field effect. The calculated chemical shifts agree well with the observed shifts (RMS error of 0.106 ppm for the data set of 257 entries). Copyright © 2014 John Wiley & Sons, Ltd.


Cobas C.,Mestrelab Research | Iglesias I.,Mestrelab Research | Seoane F.,Mestrelab Research
Magnetic Resonance in Chemistry | Year: 2015

Touch-screen computers are emerging as a popular platform for many applications, including those in chemistry and analytical sciences. In this work, we present our implementation of a new NMR 'app' designed for hand-held and portable touch-controlled devices, such as smartphones and tablets. It features a flexible architecture formed by a powerful NMR processing and analysis kernel and an intuitive user interface that makes full use of the smart devices haptic capabilities. Routine 1D and 2D NMR spectra acquired in most NMR instruments can be processed in a fully unattended way. More advanced experiments such as non-uniform sampled NMR spectra are also supported through a very efficient parallelized Modified Iterative Soft Thresholding algorithm. Specific technical development features as well as the overall feasibility of using NMR software apps will also be discussed. All aspects considered the functionalities of the app allowing it to work as a stand-alone tool or as a 'companion' to more advanced desktop applications such as Mnova NMR. Copyright © 2015 John Wiley & Sons, Ltd.


PubMed | Mestrelab Research and Autonomous University of Barcelona
Type: | Journal: Journal of magnetic resonance (San Diego, Calif. : 1997) | Year: 2016

Covariance processing is a versatile processing tool to generate synthetic NMR spectral representations without the need to acquire time-consuming experimental datasets. Here we show that even experimentally prohibited NMR spectra can be reconstructed by introducing key features of a reference 1D CHn-edited spectrum into standard 2D spectra. This general procedure is illustrated with the calculation of experimentally infeasible multiplicity-edited pure-shift NMR spectra of some very popular homonuclear (ME-psCOSY and ME-psTOCSY) and heteronuclear (ME-psHSQC-TOCSY and ME-psHMBC) experiments.


PubMed | Mestrelab Research, Merck And Co. and Autonomous University of Barcelona
Type: | Journal: Journal of magnetic resonance (San Diego, Calif. : 1997) | Year: 2016

The current Pros and Cons of a processing protocol to generate pure chemical shift NMR spectra using Generalized Indirect Covariance are presented and discussed. The transformation of any standard 2D homonuclear and heteronuclear spectrum to its pure shift counterpart by using a reference DIAG spectrum is described. Reconstructed pure shift NMR spectra of NOESY, HSQC, HSQC-TOCSY and HSQMBC experiments are reported for the target molecule strychnine.


PubMed | Mestrelab Research
Type: Journal Article | Journal: Magnetic resonance in chemistry : MRC | Year: 2015

Touch-screen computers are emerging as a popular platform for many applications, including those in chemistry and analytical sciences. In this work, we present our implementation of a new NMR app designed for hand-held and portable touch-controlled devices, such as smartphones and tablets. It features a flexible architecture formed by a powerful NMR processing and analysis kernel and an intuitive user interface that makes full use of the smart devices haptic capabilities. Routine 1D and 2D NMR spectra acquired in most NMR instruments can be processed in a fully unattended way. More advanced experiments such as non-uniform sampled NMR spectra are also supported through a very efficient parallelized Modified Iterative Soft Thresholding algorithm. Specific technical development features as well as the overall feasibility of using NMR software apps will also be discussed. All aspects considered the functionalities of the app allowing it to work as a stand-alone tool or as a companion to more advanced desktop applications such as Mnova NMR.

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