Journal of Magnetic Resonance Open最新文献

{"title":"17O hyperfine spectroscopy in surface chemistry and catalysis","authors":"Yu-Kai Liao ,&nbsp;Paolo Cleto Bruzzese ,&nbsp;Enrico Salvadori ,&nbsp;Mario Chiesa","doi":"10.1016/j.jmro.2023.100101","DOIUrl":"https://doi.org/10.1016/j.jmro.2023.100101","url":null,"abstract":"<div><p>Oxide-based materials are of key technological importance in different areas including advanced functional materials, solid state chemistry and catalysis. Many of the key questions concerning these areas involve understanding the chemical bond between the metal and the oxygen ions in the first or subsequent coordinating shells. The spectroscopic study of oxygen is therefore of fundamental importance to elucidate the complex interfacial coordination chemistry that underlies the development of metal-oxide supported catalysts and other advanced materials. Oxygen atoms at solid surfaces or lining the pores of zeolite frameworks play a vital role in stabilizing and defining the electronic and geometric structure of single metal atoms or clusters that act as catalytically active sites. In the case of paramagnetic species, EPR and its related hyperfine techniques offer a unique opportunity to explore and understand the nature of the chemical bonding in metal-oxide systems through the detection of the ¹⁷O hyperfine interaction. In this perspective we offer an overview of experimental considerations and relevant examples specific to ¹⁷O hyperfine spectroscopy of transition metal ions in zeolites relevant to catalysis. ¹⁷O hyperfine coupling values are obtained, which allow discriminating σ- and π-bonding channels in metal-oxygen bonds involving first-row transition metal ions. An exhaustive collection of ¹⁷O hyperfine and nuclear quadrupole couplings in different systems including molecular and biomolecular chemistry is provided, emphasizing the connection between interfacial and molecular inorganic coordination chemistry.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100101"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3138355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A primer in pulse EPR-based hyperfine spectroscopy for NMR spectroscopists","authors":"Nino Wili","doi":"10.1016/j.jmro.2023.100108","DOIUrl":"https://doi.org/10.1016/j.jmro.2023.100108","url":null,"abstract":"<div><p>The theoretical foundations of NMR and EPR are very similar. Nevertheless, the fields differ significantly in practical aspects. This primer is an attempt to bridge some of the gaps between the fields, and at the same time it highlights some applications of pulse EPR. Basic EPR pulse sequences to detect nuclei in the vicinity of unpaired electrons are introduced. An emphasis is placed on explaining the concept to researchers familiar with NMR. The theoretical background as well as examples are given for electron-nuclear double resonance (ENDOR), electron-spin echo envelope modulation (ESEEM), including hyperfine sublevel correlation spectroscopy (HYSCORE), and electron double resonance (ELDOR)-detected NMR.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100108"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3138356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RF coil efficacy for efficient spin control in low field magnetic resonance experiments✰","authors":"Michele N. Martin,&nbsp;Anthony B. Kos,&nbsp;Stephen E. Russek,&nbsp;Karl F. Stupic","doi":"10.1016/j.jmro.2023.100110","DOIUrl":"https://doi.org/10.1016/j.jmro.2023.100110","url":null,"abstract":"<div><p>At low magnetic fields (&lt;1 T), the low loss of radio frequency (RF) coils can cause RF pulses, in magnetic resonance (MR) experiments, to suffer from long rise and fall times. When severe, long rise and fall times can result in RF pulses with undesirable and/or unexpected shapes, lengths, and amplitudes leading to inadequate spin control during an MR experiment. Experimentally, the lack of spin control becomes evident in the shape of the nutation curve and the inversion efficiency, the degree to which full inversion is accomplished following a 180° pulse. Lowering the quality factor (Q) of tuned coil is shown to reduce the duration of the rise and fall times. The effects of long rise and fall times on the spin behavior during an MR experiment is explored. It is shown that the inversion efficiency can be used to provide a threshold that ensures high fidelity pulses with adequate spin control.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100110"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3138357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytical descriptions of (multiple-contact) cross-polarization dynamics and spin-lattice relaxation in solid alanine","authors":"Jérôme Hirschinger,&nbsp;Jésus Raya","doi":"10.1016/j.jmro.2023.100128","DOIUrl":"10.1016/j.jmro.2023.100128","url":null,"abstract":"<div><p>In this work, several exact and approximate analytical solutions to the quantum master equation are derived using both classical and non-classical coupling models to describe the kinetics of Hartmann-Hahn cross-polarization (HHCP) and multiple-contact CP (MC<img>CP). Moreover, the analytical solution originally obtained by Naito and McDowell [J. Chem. Phys. 84 (1986) 4181.] is shown to be incorrect and the different regimes of spin diffusion and <span><math><msub><mi>T</mi><mrow><mn>1</mn><mi>ρ</mi></mrow></msub></math></span> relaxation are characterized by the amplitude of the second stage of the HHCP dynamics and the HHCP/MC<img>CP crossing time. The analysis of the ¹H–¹³C HHCP and MC<img>CP dynamics together with (Lee-Goldburg) ¹H <span><math><msub><mi>T</mi><mrow><mn>1</mn><mi>ρ</mi></mrow></msub></math></span> relaxation experimental data provides a consistent picture of spin dynamics in solid alanine and explains the apparent discrepancies previously observed between <span><math><msub><mi>T</mi><mrow><mn>1</mn><mi>ρ</mi></mrow></msub></math></span> and <span><math><msub><mi>T</mi><mn>1</mn></msub></math></span> relaxation measurements. The CH and CH₃ protons relax as expected <em>via</em> spin diffusion towards the NH₃ protons but the assumption of common proton spin temperature, in which the bottleneck of relaxation is at the NH₃ sites, generally valid for <span><math><msub><mi>T</mi><mn>1</mn></msub></math></span> relaxation breaks down for <span><math><msub><mi>T</mi><mrow><mn>1</mn><mi>ρ</mi></mrow></msub></math></span> relaxation. A diffusion-limited situation in which nuclear Zeeman energy is transferred to the lattice faster than can be supplied by spin diffusion is observed instead.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100128"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441023000365/pdfft?md5=8634b4f0bfee2e20f4a4370925e073c3&pid=1-s2.0-S2666441023000365-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78948571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A nitroxide-containing cathode material for organic radical batteries studied with pulsed EPR spectroscopy","authors":"Ilia Kulikov ,&nbsp;Anatoliy A. Vereshchagin ,&nbsp;Daniil A. Lukianov ,&nbsp;Oleg V. Levin ,&nbsp;Jan Behrends","doi":"10.1016/j.jmro.2023.100134","DOIUrl":"https://doi.org/10.1016/j.jmro.2023.100134","url":null,"abstract":"<div><p>An electron spin echo in a nitroxide-containing polymer cathode film for organic radical batteries is observed for various states of charge at cryogenic temperatures. The EPR-detected state of charge (ESOC), as inferred from the number of paramagnetic centers in the film, is compared to the results of Coulomb counting based on galvanostatic charging. Spin concentration, longitudinal relaxation times <span><math><msub><mrow><mi>T</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and phase memory times <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>m</mi></mrow></msub></math></span> strongly correlate with the ESOC. In the discharged film, the spin concentration reaches <span><math><mrow><mfenced><mrow><mn>5</mn><mo>±</mo><mn>3</mn></mrow></mfenced><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>20</mn></mrow></msup></mrow></math></span> cm⁻³, causing a phase memory time <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>≪</mo></mrow></math></span> 100 ns (shorter than the resonator ring-down time) that hinders the detection of the spin echo. In the charged film, the decreased spin concentration results in a longer <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>m</mi></mrow></msub></math></span> between 100 ns and 300 ns that enables spin-echo detection, yet limits the length of the microwave pulse sequence. The short, broad-band pulses cause instantaneous diffusion in the unoxidized domains across the oxidized film, affecting the relative peak intensities in the pulsed EPR spectrum. By simulating the spectral distortion caused by instantaneous diffusion, we obtain information on the local spin concentration, which complements the information on the ‘bulk’ spin concentration determined by electrochemistry and continuous-wave EPR spectroscopy.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100134"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441023000420/pdfft?md5=88af9c2697fd9712c8b322df95896bb8&pid=1-s2.0-S2666441023000420-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91962567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing oxide-based glass structures by solid-state NMR: Opportunities and limitations","authors":"Mattias Edén","doi":"10.1016/j.jmro.2023.100112","DOIUrl":"https://doi.org/10.1016/j.jmro.2023.100112","url":null,"abstract":"<div><p>This Primer critically reviews the possibilities and limitations of probing the short-range structure of an oxide-based glass by routine magic-angle spinning (MAS) or triple-quantum MAS (3QMAS) nuclear magnetic resonance (NMR) experiments. We briefly outline the structural features of oxide-based glasses and the basics of solid-state NMR. Besides suggesting guidelines for selecting favorable experimental conditions and important considerations for recording high-quality MAS NMR spectra amenable for subsequent analysis, we review options for extracting NMR observables and their distributions from spins-1/2 as well as half-integer spin quadrupolar nuclei. Considering that the isotropic chemical shift remains the primary probe of local structure by MAS NMR, we thoroughly review its dependence on the short-range oxide-based glass parameters from the viewpoint of a very simple and intuitive but qualitative model. The utility of deconvolutions of notably ²⁹Si and ³¹P MAS NMR spectra are discussed critically. We also suggest alternative yet qualitative analysis options that are available whenever MAS NMR spectral deconvolutions are not warranted without additional information, which incidentally applies to a majority of modern multicomponent glasses.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100112"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1826464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient polarization redistribution in hyperpolarized 1-D-propane produced via pairwise parahydrogen addition","authors":"Nuwandi M. Ariyasingha ,&nbsp;Shiraz Nantogma ,&nbsp;Anna Samoilenko ,&nbsp;Oleg G. Salnikov ,&nbsp;Nikita V. Chukanov ,&nbsp;Larisa M. Kovtunova ,&nbsp;Igor V. Koptyug ,&nbsp;Eduard Y. Chekmenev","doi":"10.1016/j.jmro.2023.100135","DOIUrl":"https://doi.org/10.1016/j.jmro.2023.100135","url":null,"abstract":"<div><p>Parahydrogen-Induced Polarization (PHIP) is NMR hyperpolarization technique that has matured from fundamental science to a biomedical tool for production of hyperpolarized MRI contrast agents. The spin order of nascent parahydrogen-derived protons can be employed directly for enhancement of their NMR signals or for polarization transfer to other nuclei in the hydrogenation product. In this work, we study the process of pairwise parahydrogen addition to propylene, which results in symmetric propane molecule with substantially enhanced methyl and methylene NMR signals. Specifically, we have synthesized site-selectively isotopically labeled 3-<span>d</span>-propylene molecule to study polarization dynamics in the resulting monodeuterated propane after pairwise parahydrogen addition. The deuterium presence in the hyperpolarized propane product results in a minute isotope chemical shift effect allowing to distinguish the proton resonances of CH₃ and CH₂D groups at 600 MHz. Pairwise parahydrogen 1,2-addition to 3-<span>d</span>-propylene was first confirmed by performing the reaction inside a 600 MHz NMR spectrometer, <em>i.e</em>., in the weakly-coupled regime at 14 T, where proton polarization dynamics is restricted to the molecular sites of parahydrogen addition. However, when the pairwise parahydrogen addition is performed in the strongly-coupled regime, <em>i.e</em>., at the Earth's magnetic field, efficient polarization transfer to CH₂D protons is readily observed, leading to polarization redistribution between the three inequivalent sites. This finding is important as it sheds light on polarization dynamics in the strongly coupled symmetric spin systems such as propane studied here—the presented results are expected to be applicable to other spin systems such as butane.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100135"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441023000432/pdfft?md5=27574b8b0966d42351dc5e56ded5517c&pid=1-s2.0-S2666441023000432-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92087351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facile hyperpolarization chemistry for molecular imaging and metabolic tracking of [1–13C]pyruvate in vivo","authors":"Keilian MacCulloch ,&nbsp;Austin Browning ,&nbsp;David O. Guarin Bedoya ,&nbsp;Stephen J. McBride ,&nbsp;Mustapha B. Abdulmojeed ,&nbsp;Carlos Dedesma ,&nbsp;Boyd M. Goodson ,&nbsp;Matthew S. Rosen ,&nbsp;Eduard Y. Chekmenev ,&nbsp;Yi-Fen Yen ,&nbsp;Patrick TomHon ,&nbsp;Thomas Theis","doi":"10.1016/j.jmro.2023.100129","DOIUrl":"https://doi.org/10.1016/j.jmro.2023.100129","url":null,"abstract":"<div><p>Hyperpolarization chemistry based on reversible exchange of parahydrogen, also known as Signal Amplification By Reversible Exchange (SABRE), is a particularly simple approach to attain high levels of nuclear spin hyperpolarization, which can enhance NMR and MRI signals by many orders of magnitude. SABRE has received significant attention in the scientific community since its inception because of its relative experimental simplicity and its broad applicability to a wide range of molecules, however, <em>in vivo</em> detection of molecular probes hyperpolarized by SABRE has remained elusive. Here we describe a first demonstration of SABRE-hyperpolarized contrast detected <em>in vivo</em>, specifically using hyperpolarized [1–¹³C]pyruvate. Biocompatible formulations of hyperpolarized [1–¹³C]pyruvate in, both, methanol-water, and ethanol-water mixtures followed by dilution with saline and catalyst filtration were prepared and injected into healthy Sprague Dawley and Wistar rats. Effective hyperpolarization-catalyst removal was performed with silica filters without major losses in hyperpolarization. Metabolic conversion of pyruvate to lactate, alanine, and bicarbonate was detected <em>in vivo</em>. Pyruvate-hydrate was also observed as a minor byproduct. Measurements were performed on the liver and kidney at 4.7 T via time-resolved spectroscopy and chemical-shift-resolved MRI. In addition, whole-body metabolic measurements were obtained using a cryogen-free 1.5 T MRI system, illustrating the utility of combining lower-cost MRI systems with simple, low-cost hyperpolarization chemistry to develop safe and scalable molecular imaging.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100129"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3266171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hyperpolarized 13C NMR for longitudinal in-cell metabolism using a mobile 3D cell culture system","authors":"T.B.W. Mathiassen ,&nbsp;A.E. Høgh ,&nbsp;M. Karlsson ,&nbsp;S. Katsikis ,&nbsp;K. Wang ,&nbsp;M. Pennestri ,&nbsp;J.H. Ardenkjær-Larsen ,&nbsp;P.R. Jensen","doi":"10.1016/j.jmro.2023.100131","DOIUrl":"10.1016/j.jmro.2023.100131","url":null,"abstract":"<div><p>Hyperpolarization with the dissolution dynamic nuclear polarization (dDNP) technique yields &gt; 10,000-fold signal increases for NMR-active nuclei (e.g. ¹³C). Hyperpolarized ¹³C-labeled metabolic tracer molecules thus allow real-time observations of biochemical pathways in living cellular systems without interfering background. This methodology lends itself to the direct observation of altered intracellular reaction chemistry imparted for instance by drug treatment, infections, or other diseases. A reoccurring challenge for longitudinal cell studies of mammalian cells with NMR and dDNP-NMR is maintaining cell viability in the NMR spectrometer. 3D cell culture methods are increasing in popularity because they provide a physiologically more relevant environment compared to 2D cell cultures. Based on such strategies a mobile 3D culture system was devised. The clinical drug etoposide was used to treat cancer cells (HeLa) and the resulting altered metabolism was measured using hyperpolarized [1–¹³C]pyruvate. We show that sustaining the cell cultivation in cell incubators and only transferring the cells to the NMR spectrometer for the few minutes required for the dDNP-NMR measurements is an attractive alternative to cell maintenance in the NMR tube. High cell viability is sustained, and experimental throughput is many doubled.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100131"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441023000390/pdfft?md5=1fb698b32491f80f5153bc638f0b5899&pid=1-s2.0-S2666441023000390-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86035083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An introduction to one- and two-dimensional lineshape analysis of chemically exchanging systems","authors":"Christopher A. Waudby ,&nbsp;Ignacio Alfonso","doi":"10.1016/j.jmro.2023.100102","DOIUrl":"https://doi.org/10.1016/j.jmro.2023.100102","url":null,"abstract":"<div><p>Molecules are dynamic entities, and understanding intra- and inter-molecular reactions and changes in conformation is one of the most fascinating, important and complex subjects in NMR. Conformational changes and chemical reactions result in observed spins exchanging between different magnetic environments, and the sensitivity of NMR spectra to such dynamic processes has been recognised since the earliest days of the field. Careful analysis of such spectra, acquired using one- or two-dimensional experiments, can provide insight into structural, thermodynamic, kinetic and mechanistic aspects of the underlying exchange process. The theoretical principles of these lineshape analysis methods will be introduced in this article, alongside a practical discussion of calculation methods, data acquisition and analysis software.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"16 ","pages":"Article 100102"},"PeriodicalIF":2.624,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3266169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}