MR - recent papers
https://mr.copernicus.org/articles/
Combined list of the recent articles of the journal Magnetic Resonance and the recent discussion forum Magnetic Resonance DiscussionsSecond harmonic electron paramagnetic resonance spectroscopy and imaging reveal metallic lithium depositions in Li-ion batteries
https://doi.org/10.5194/mr-2024-5
<b>Second harmonic electron paramagnetic resonance spectroscopy and imaging reveal metallic lithium depositions in Li-ion batteries</b><br>
Charles-Emmanuel Dutoit, Hania Ahouari, Quentin Denoyelle, Simon Pondaven, and Hervé Vezin<br>
Magn. Reson. Discuss., https://doi.org/10.5194/mr-2024-5,2024<br>
<b>Preprint under review for MR</b> (discussion: open, 1 comment)<br>
In our study, we correlate the first and the second harmonic detection modes of continuous wave electron paramagnetic resonance to identify metallic lithium traces present on the graphite anode after multi electrochemical cycles. Such metallic complexes are a source of limitations which reduces battery life and lead to serious safety issues. To improve their detection, we propose to record simultaneously the first and the second harmonic EPR spectrum.
2024-03-18T07:13:20+01:00Dynamic averaging of anisotropic interactions and its dependence on motional time scales in MAS solid-state NMR
https://doi.org/10.5194/mr-2024-4
<b>Dynamic averaging of anisotropic interactions and its dependence on motional time scales in MAS solid-state NMR</b><br>
Kathrin Aebischer, Lea Marie Becker, Paul Schanda, and Matthias Ernst<br>
Magn. Reson. Discuss., https://doi.org/10.5194/mr-2024-4,2024<br>
<b>Preprint under review for MR</b> (discussion: final response, 8 comments)<br>
To characterize the amplitude of dynamic processes in molecules, anisotropic parameters can be measured using solid-state NMR. However, it is not clear motions on which time scales lead to such a scaling of the anisotropic interactions. Using numerical simulations in small spin systems we could show that mostly the magnitude of the anisotropic interaction determines the range of time scales detected by the scaled anisotropic interaction and experimental parameters play a very minor role.
2024-02-21T07:13:20+01:00An automated NMR platform with light-coupled cryogenic probes to detect low micromolar samples
https://doi.org/10.5194/mr-2024-3
<b>An automated NMR platform with light-coupled cryogenic probes to detect low micromolar samples</b><br>
Wolf Wüster, Pit Gebbers, Alois Renn, Matthias Bütikofer, Roland Riek, and Felix Torres<br>
Magn. Reson. Discuss., https://doi.org/10.5194/mr-2024-3,2024<br>
<b>Revised manuscript under review for MR</b> (discussion: final response, 6 comments)<br>
Drug discovery requires the testing of a large number of samples to identify molecules with a potential therapeutic potential. The recent development of methods to perform such tests within seconds using sample illumination in a magnetic field could increase the throughput of such studies. We present a setup that integrates light into fully automated and commercially available instrumentation. This platform upgrade can increase the drug discovery throughput by a factor of 20 to 50-fold.
2024-02-12T07:13:20+01:00A modular library for fast prototyping of solution-state nuclear magnetic resonance experiments
https://doi.org/10.5194/mr-2024-2
<b>A modular library for fast prototyping of solution-state nuclear magnetic resonance experiments</b><br>
Michał Górka and Wiktor Koźmiński<br>
Magn. Reson. Discuss., https://doi.org/10.5194/mr-2024-2,2024<br>
<b>Revised manuscript accepted for MR</b> (discussion: closed, 6 comments)<br>
We have written a programming library for biological NMR, a commonly used research method. Its use simplifies (makes it faster and less error-prone) development of new research methods. We demonstrate that it allows for consolidating several experimental methods into one file without adding complexity. We hope that it will be of use for other groups developing NMR experiments.
2024-01-31T07:13:20+01:00Deuteration of proteins boosted by cell lysates: high-resolution amide and Hα MAS NMR without re-protonation bottleneck
https://doi.org/10.5194/mr-2024-1
<b>Deuteration of proteins boosted by cell lysates: high-resolution amide and Hα MAS NMR without re-protonation bottleneck</b><br>
Federico Napoli, Jia-Ying Guan, Charles-Adrien Arnaud, Pavel Macek, Hugo Fraga, Cécile Breyton, and Paul Schanda<br>
Magn. Reson. Discuss., https://doi.org/10.5194/mr-2024-1,2024<br>
<b>Revised manuscript accepted for MR</b> (discussion: closed, 6 comments)<br>
Protons (1H) are useful reporters of protein structure and dynamics in solid-state NMR. However, 1H abundance is detrimental to the resolution of NMR spectra. Substituting 1H by deuterons has been an efficient strategy to improve spectral quality, but when the crucial backbone amide sites are not protonated, much information is loss. We propose a method to completely protonate the amide sites, while maintaining high-resolution information, which partially also extends to backbone alpha-1H.
2024-01-17T07:13:20+01:00Solid-state 13C-NMR spectroscopic determination of side-chain mobilities in zirconium-based metal–organic frameworks
https://doi.org/10.5194/mr-5-1-2024
<b>Solid-state 13C-NMR spectroscopic determination of side-chain mobilities in zirconium-based metal–organic frameworks</b><br>
Günter Hempel, Ricardo Kurz, Silvia Paasch, Kay Saalwächter, and Eike Brunner<br>
Magn. Reson., 5, 1–20, https://doi.org/10.5194/mr-5-1-2024, 2024<br>
Investigations of metal–organic frameworks are presented. This substance class is of interest for applications in gas storage (hydrogen, methane), separation, catalysis, and sensor technology. The properties of the material depend on the mobility of alkyl or alkyloxy side chains. We have determined that the side-chain methylene groups move highly anisotropically with a relatively short correlation time. Furthermore, we could improve the analysis procedure for the experiment used here.
2024-01-05T07:13:20+01:00Various facets of intermolecular transfer of phase coherence by nuclear dipolar fields
https://doi.org/10.5194/mr-4-271-2023
<b>Various facets of intermolecular transfer of phase coherence by nuclear dipolar fields</b><br>
Philippe Pelupessy<br>
Magn. Reson., 4, 271–283, https://doi.org/10.5194/mr-4-271-2023, 2023<br>
In nuclear magnetic resonance, the magnetization of abundantly present nuclei contributes to the overall field felt by the same nuclei through intermolecular dipolar interactions. This has led to many surprising discoveries, such as multiple-spin echoes and intermolecular cross-peaks in 2D spectroscopy. In this work, the effect of the dipolar field under continuous irradiation is investigated. Various methods to obtain intermolecular transfer of phase coherences are presented.
2023-12-21T07:13:20+01:00The solid effect of dynamic nuclear polarization in liquids – accounting for g-tensor anisotropy at high magnetic fields
https://doi.org/10.5194/mr-4-243-2023
<b>The solid effect of dynamic nuclear polarization in liquids – accounting for g-tensor anisotropy at high magnetic fields</b><br>
Deniz Sezer, Danhua Dai, and Thomas F. Prisner<br>
Magn. Reson., 4, 243–269, https://doi.org/10.5194/mr-4-243-2023, 2023<br>
We recently liberated the solid effect of dynamic nuclear polarization (DNP) from its perturbative treatment by describing the relevant spin dynamics in a time domain. This allows us to easily account for dynamical processes that modulate the spin interactions in liquids, like the translational diffusion of spins. Here we additionally model the slow rotational diffusion of the polarizing agent and analyze DNP data from nitroxide spin labels in lipid bilayers at 9.4 T.
2023-11-01T07:13:20+01:00Lipid Removal in Deuterium Metabolic Imaging (DMI) using Spatial Prior Knowledge
https://doi.org/10.5194/mr-2023-12
<b>Lipid Removal in Deuterium Metabolic Imaging (DMI) using Spatial Prior Knowledge</b><br>
Robin A. de Graaf, Yanning Liu, Zachary A. Corbin, and Henk M. De Feyter<br>
Magn. Reson. Discuss., https://doi.org/10.5194/mr-2023-12,2023<br>
<b>Revised manuscript accepted for MR</b> (discussion: closed, 5 comments)<br>
Deuterium Metabolic Imaging (DMI) is a novel method to obtain images of dynamic metabolism in the living human brain. While DMI is generally simple and robust, small signals from deuterated skull lipids can distort the metabolic information within the brain. Here we use MRI-based information on brain and skull locations to remove lipid signals from DMI data. With an average 90 % lipid removal, DMI is used to generate distinct and artifact-free metabolic maps on patients with brain tumors.
2023-09-20T07:13:20+02:00Cryogenic-compatible spherical rotors and stators for magic angle spinning dynamic nuclear polarization
https://doi.org/10.5194/mr-4-231-2023
<b>Cryogenic-compatible spherical rotors and stators for magic angle spinning dynamic nuclear polarization</b><br>
Lauren E. Price, Nicholas Alaniva, Marthe Millen, Till Epprecht, Michael Urban, Alexander Däpp, and Alexander B. Barnes<br>
Magn. Reson., 4, 231–241, https://doi.org/10.5194/mr-4-231-2023, 2023<br>
This paper describes the design and implementation of new technology for nuclear magnetic resonance, which is a technique used to understand the molecular structure and dynamics of many systems. The spherical sample container and its apparatus introduced in this paper are used to perform initial proof-of-principle experiments at cryogenic temperatures. Further development of this technology will facilitate more flexibility in magnetic resonance experiments.
2023-09-06T07:13:20+02:00Asymmetry in three-site relaxation exchange NMR
https://doi.org/10.5194/mr-4-217-2023
<b>Asymmetry in three-site relaxation exchange NMR</b><br>
Bernhard Blümich, Matthew Parziale, and Matthew Augustine<br>
Magn. Reson., 4, 217–229, https://doi.org/10.5194/mr-4-217-2023, 2023<br>
Diffusive motion in confined three-site relaxation exchange was studied in Monte Carlo simulations. In thermodynamic equilibrium, the cross-peaks in NMR relaxation exchange maps are symmetric. Asymmetry is observed in mass-balanced driven equilibrium corresponding to circular flow. If this motion can be stimulated by external forces, it can be beneficial to heterogeneous catalysis.
2023-08-24T07:13:20+02:00Performance of the cross-polarization experiment in conditions of radiofrequency field inhomogeneity and slow to ultrafast magic angle spinning (MAS)
https://doi.org/10.5194/mr-4-199-2023
<b>Performance of the cross-polarization experiment in conditions of radiofrequency field inhomogeneity and slow to ultrafast magic angle spinning (MAS)</b><br>
Andrej Šmelko, Jan Blahut, Bernd Reif, and Zdeněk Tošner<br>
Magn. Reson., 4, 199–215, https://doi.org/10.5194/mr-4-199-2023, 2023<br>
We present a tutorial on the cross-polarization experiment, which has been the main method of magnetization transfer in solid-state NMR for decades. We explain the principles of its volume-selective performance in the presence of magic angle spinning and radiofrequency field inhomogeneity and the decrease in efficiency with increasing sample rotation frequency.
2023-08-15T07:13:20+02:00Cell-free synthesis of proteins with selectively 13C-labelled methyl groups from inexpensive precursors
https://doi.org/10.5194/mr-4-187-2023
<b>Cell-free synthesis of proteins with selectively 13C-labelled methyl groups from inexpensive precursors</b><br>
Damian Van Raad, Gottfried Otting, and Thomas Huber<br>
Magn. Reson., 4, 187–197, https://doi.org/10.5194/mr-4-187-2023, 2023<br>
A novel cell-free protein synthesis system called eCells produces amino acids based on specific isotopes using low-cost precursors. The system selectively labels methyl groups, i.e valine and leucine, with high efficiency. eCells achieve high levels of 13C incorporation and deuteration in protein preparations, making them suitable for NMR experiments of large protein complexes. They are easy to prepare, can be scaled up in volume and are a promising tool for protein production and NMR studies.
2023-07-19T07:13:20+02:00Modelling and correcting the impact of RF pulses for continuous monitoring of hyperpolarized NMR
https://doi.org/10.5194/mr-4-175-2023
<b>Modelling and correcting the impact of RF pulses for continuous monitoring of hyperpolarized NMR</b><br>
Gevin von Witte, Matthias Ernst, and Sebastian Kozerke<br>
Magn. Reson., 4, 175–186, https://doi.org/10.5194/mr-4-175-2023, 2023<br>
Hyperpolarization methods offer the possibility of overcoming the inherent sensitivity limits of nuclear magnetic resonance (NMR) given by the thermal Boltzmann spin distribution. The radio-frequency (RF) pulses to monitor the hyperpolarization process alter it by depleting the created magnetization. Possible corrections are simulated with a rate-equation model containing a single source and relaxation rate. The accuracy is demonstrated experimentally, enabling the use of larger flip angles.
2023-07-13T07:13:20+02:00Non-perturbative treatment of the solid effect of dynamic nuclear polarization
https://doi.org/10.5194/mr-4-129-2023
<b>Non-perturbative treatment of the solid effect of dynamic nuclear polarization</b><br>
Deniz Sezer<br>
Magn. Reson., 4, 129–152, https://doi.org/10.5194/mr-4-129-2023, 2023<br>
Since its discovery 65 years ago, the solid-state dynamic nuclear polarization effect has been rationalized in terms of mixing of the Zeeman energy levels. Before becoming aware of this explanation, Erb, Motchane and Uebersfeld proposed a dynamical equation to make sense of their experiments. Here we provide a formal justification of their phenomenological equation. The result is a different way of thinking about the solid-state effect, with novel implications for the effect in liquids.
2023-06-05T07:13:20+02:00The solid effect of dynamic nuclear polarization in liquids
https://doi.org/10.5194/mr-4-153-2023
<b>The solid effect of dynamic nuclear polarization in liquids</b><br>
Deniz Sezer<br>
Magn. Reson., 4, 153–174, https://doi.org/10.5194/mr-4-153-2023, 2023<br>
We show that the field profile of the solid effect in liquids is rich in dynamical information, including about timescales of molecular diffusion. We develop a general theoretical framework for extracting this information through quantitative fits to the experimental data. Unusual peaks in the enhancement field profile, which resemble thermal mixing but are not related to it, are demonstrated to arise in liquids under some conditions. These additionally restrict the dynamical parameters.
2023-06-05T07:13:20+02:00Time-domain proton-detected local-field NMR for molecular structure determination in complex lipid membranes
https://doi.org/10.5194/mr-4-115-2023
<b>Time-domain proton-detected local-field NMR for molecular structure determination in complex lipid membranes</b><br>
Anika Wurl, Kay Saalwächter, and Tiago Mendes Ferreira<br>
Magn. Reson., 4, 115–127, https://doi.org/10.5194/mr-4-115-2023, 2023<br>
R-proton-detected local-field NMR is a powerful method to obtain structural information from biological membrane models. However, the conventional analysis of experiments, by using a Fourier transform in the indirect time-domain and reading-off splittings, is unsuitable to investigate complex systems. One then needs to model the experimental data. Fitting the experimental data with simulations that account for radiofrequency field inhomogeneity enables accurate modeling of R-PDLF data.
2023-05-12T07:13:20+02:00Introduction to “Geoffrey Bodenhausen Festschrift”
https://doi.org/10.5194/mr-4-111-2023
<b>Introduction to “Geoffrey Bodenhausen Festschrift”</b><br>
Daniel Abergel and Fabien Ferrage<br>
Magn. Reson., 4, 111–114, https://doi.org/10.5194/mr-4-111-2023, 2023<br>
2023-05-02T07:13:20+02:00Simulation of NMR spectra at zero and ultralow fields from A to Z – a tribute to Prof. Konstantin L'vovich Ivanov
https://doi.org/10.5194/mr-4-87-2023
<b>Simulation of NMR spectra at zero and ultralow fields from A to Z – a tribute to Prof. Konstantin L'vovich Ivanov</b><br>
Quentin Stern and Kirill Sheberstov<br>
Magn. Reson., 4, 87–109, https://doi.org/10.5194/mr-4-87-2023, 2023<br>
This tutorial paper shows how to simulate NMR spectra at zero to ultralow fields. The process is presented in detail, including the tricks that are usually omitted from research papers and assuming as little prior knowledge from the reader as possible. In this attempt to make NMR simulation approachable, the authors wish to pay tribute to the late Prof. Konstantin L’vovich Ivanov.
2023-04-11T07:13:20+02:00Multidimensional encoding of restricted and anisotropic diffusion by double rotation of the q vector
https://doi.org/10.5194/mr-4-73-2023
<b>Multidimensional encoding of restricted and anisotropic diffusion by double rotation of the q vector</b><br>
Hong Jiang, Leo Svenningsson, and Daniel Topgaard<br>
Magn. Reson., 4, 73–85, https://doi.org/10.5194/mr-4-73-2023, 2023<br>
Diffusion MRI is a clinically important tool for noninvasive detection of pathological conditions that lead to microscopic changes in cell and tissue structures, but this technique suffers from interpretational ambiguities when applied to heterogeneous and disordered tissues comprising cells with multiple sizes, shapes, and orientations. We propose a simple scheme to encode the MRI signal with a sufficient amount of information to resolve and study all properties simultaneously.
2023-03-15T07:13:20+01:00