Progress in Nuclear Magnetic Resonance Spectroscopy最新文献

{"title":"Dynamics in inorganic glass-forming liquids by NMR spectroscopy","authors":"Sabyasachi Sen","doi":"10.1016/j.pnmrs.2019.11.001","DOIUrl":"10.1016/j.pnmrs.2019.11.001","url":null,"abstract":"<div><p>Dynamical NMR spectroscopy provides unique mechanistic understanding of the transport and relaxation processes in glass-forming liquids over timescales typically ranging from ~10⁻⁹ s to ~10² s, and thus has been used extensively in the past to study the dynamical behavior of polymeric and organic glass-forming liquids. However, reports in the literature of similar studies on inorganic glass-forming liquids have remained somewhat limited due to the experimental challenges. In this contribution we present a review of the high-temperature NMR spectroscopic studies of atomic and molecular dynamics in a wide variety of inorganic glass-forming liquids including oxides, halides and chalcogenides as well as select ionic liquids and molten salts. The significance of these dynamical processes in understanding the nature of the liquid-to-glass transition and their connection with the macroscopic transport properties of these liquids are discussed.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"116 ","pages":"Pages 155-176"},"PeriodicalIF":6.1,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.11.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37704660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast time-resolved NMR with non-uniform sampling","authors":"Dariusz Gołowicz ,&nbsp;Paweł Kasprzak ,&nbsp;Vladislav Orekhov ,&nbsp;Krzysztof Kazimierczuk","doi":"10.1016/j.pnmrs.2019.09.003","DOIUrl":"10.1016/j.pnmrs.2019.09.003","url":null,"abstract":"<div><p>NMR spectroscopy is a versatile tool for studying time-dependent processes: chemical reactions, phase transitions or macromolecular structure changes. However, time-resolved NMR is usually based on the simplest among available techniques – one-dimensional spectra serving as “snapshots” of the studied process. One of the reasons is that multidimensional experiments are very time-expensive due to costly sampling of evolution time space. In this review we summarize efforts to alleviate the problem of limited applicability of multidimensional NMR in time-resolved studies. We focus on techniques based on sparse or non-uniform sampling (NUS), which lead to experimental time reduction by omitting a significant part of the data during measurement and reconstructing it mathematically, adopting certain assumptions about the spectrum. NUS spectra are faster to acquire than conventional ones and thus better suited to the role of “snapshots”, but still suffer from non-stationarity of the signal i.e. amplitude and frequency variations within a dataset. We discuss in detail how these instabilities affect the spectra, and what are the optimal ways of sampling the non-stationary FID signal. Finally, we discuss related areas of NMR where serial experiments are exploited and how they can benefit from the same NUS-based approaches.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"116 ","pages":"Pages 40-55"},"PeriodicalIF":6.1,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.09.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37704665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methyl TROSY spectroscopy: A versatile NMR approach to study challenging biological systems","authors":"Stefan Schütz,&nbsp;Remco Sprangers","doi":"10.1016/j.pnmrs.2019.09.004","DOIUrl":"10.1016/j.pnmrs.2019.09.004","url":null,"abstract":"<div><p>A major goal in structural biology is to unravel how molecular machines function in detail. To that end, solution-state NMR spectroscopy is ideally suited as it is able to study biological assemblies in a near natural environment. Based on methyl TROSY methods, it is now possible to record high-quality data on complexes that are far over 100 kDa in molecular weight. In this review, we discuss the theoretical background of methyl TROSY spectroscopy, the information that can be extracted from methyl TROSY spectra and approaches that can be used to assign methyl resonances in large complexes. In addition, we touch upon insights that have been obtained for a number of challenging biological systems, including the 20S proteasome, the RNA exosome, molecular chaperones and G-protein-coupled receptors. We anticipate that methyl TROSY methods will be increasingly important in modern structural biology approaches, where information regarding static structures is complemented with insights into conformational changes and dynamic intermolecular interactions.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"116 ","pages":"Pages 56-84"},"PeriodicalIF":6.1,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.09.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37704666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multinuclear NMR in polypeptide liquid crystals: Three fertile decades of methodological developments and analytical challenges","authors":"Philippe Lesot ,&nbsp;Christie Aroulanda ,&nbsp;Philippe Berdagué ,&nbsp;Abdelkrim Meddour ,&nbsp;Denis Merlet ,&nbsp;Jonathan Farjon ,&nbsp;Nicolas Giraud ,&nbsp;Olivier Lafon","doi":"10.1016/j.pnmrs.2019.10.001","DOIUrl":"10.1016/j.pnmrs.2019.10.001","url":null,"abstract":"<div><p>NMR spectroscopy of oriented samples makes accessible residual anisotropic intramolecular NMR interactions, such as chemical shift anisotropy (RCSA), dipolar coupling (RDC), and quadrupolar coupling (RQC), while preserving high spectral resolution. In addition, in a chiral aligned environment, enantiomers of chiral molecules or enantiopic elements of prochiral compounds adopt different average orientations on the NMR timescale, and hence produce distinct NMR spectra or signals. NMR spectroscopy in chiral aligned media is a powerful analytical tool, and notably provides unique information on (pro)chirality analysis, natural isotopic fractionation, stereochemistry, as well as molecular conformation and configuration. Significant progress has been made in this area over the three last decades, particularly using polypeptide-based chiral liquid crystals (CLCs) made of organic solutions of helically chiral polymers (as PBLG) in organic solvents. This review presents an overview of NMR in polymeric LCs. In particular, we describe the theoretical tools and the major NMR methods that have been developed and applied to study (pro)chiral molecules dissolved in such oriented solvents. We also discuss the representative applications illustrating the analytical potential of this original NMR tool. This overview article is dedicated to thirty years of original contributions to the development of NMR spectroscopy in polypeptide-based chiral liquid crystals.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"116 ","pages":"Pages 85-154"},"PeriodicalIF":6.1,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.10.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37704667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring water exchange across the blood-brain barrier using MRI","authors":"Ben R. Dickie ,&nbsp;Geoff J.M. Parker ,&nbsp;Laura M. Parkes","doi":"10.1016/j.pnmrs.2019.09.002","DOIUrl":"10.1016/j.pnmrs.2019.09.002","url":null,"abstract":"<div><p>The blood-brain barrier (BBB) regulates the transfer of solutes and essential nutrients into the brain. Growing evidence supports BBB dysfunction in a range of acute and chronic brain diseases, justifying the need for novel research and clinical tools that can non-invasively detect, characterize, and quantify BBB dysfunction <em>in-vivo</em><span>. Many approaches already exist for measuring BBB dysfunction in man using positron emission tomography and magnetic resonance imaging (e.g. dynamic contrast-enhanced MRI measurements of gadolinium leakage). This review paper focusses on MRI measurements of water exchange across the BBB, which occurs through a wide range of pathways, and is likely to be a highly sensitive marker of BBB dysfunction. Key mathematical models and acquisition methods are discussed for the two main approaches: those that utilize contrast agents to enhance relaxation rate differences between the intravascular and extravascular compartments and so enhance the sensitivity of MRI signals to BBB water exchange, and those that utilize the dynamic properties of arterial spin labelling to first isolate signal from intravascular spins and then estimate the impact of water exchange on the evolving signal. Data from studies in healthy and pathological brain tissue are discussed, in addition to validation studies in rodents.</span></p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"116 ","pages":"Pages 19-39"},"PeriodicalIF":6.1,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.09.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37704664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Matrix-assisted DOSY","authors":"Iain J. Day","doi":"10.1016/j.pnmrs.2019.09.001","DOIUrl":"10.1016/j.pnmrs.2019.09.001","url":null,"abstract":"<div><p>The analysis of mixtures by NMR spectroscopy is challenging. Diffusion-ordered NMR spectroscopy enables a pseudo-separation of species based on differences in their translational diffusion coefficients. Under the right circumstances, this is a powerful technique; however, when molecules diffuse at similar rates separation in the diffusion dimension can be poor. In addition, spectral overlap also limits resolution and can make interpretation challenging. Matrix-assisted diffusion NMR seeks to improve resolution in the diffusion dimension by utilising the differential interaction of components in the mixture with an additive to the solvent. Tuning these matrix-analyte interactions allows the diffusion resolution to be optimised. This review presents the background to matrix-assisted diffusion experiments, surveys the wide range of matrices employed, including chromatographic stationary phases, surfactants and polymers, and demonstrates the current state of the art.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"116 ","pages":"Pages 1-18"},"PeriodicalIF":6.1,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.09.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37704784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-T2 MRI: Principles and recent advances","authors":"Markus Weiger,&nbsp;Klaas P. Pruessmann","doi":"10.1016/j.pnmrs.2019.07.001","DOIUrl":"10.1016/j.pnmrs.2019.07.001","url":null,"abstract":"<div><p>Among current modalities of biomedical and diagnostic imaging, MRI stands out by virtue of its versatile contrast obtained without ionizing radiation. However, in various cases, e.g., water protons in tissues such as bone, tendon, and lung, MRI performance is limited by the rapid decay of resonance signals associated with short transverse relaxation times <em>T</em>₂ or <em>T</em>₂*. Efforts to address this shortcoming have led to a variety of specialized short-<em>T</em>₂ techniques. Recent progress in this field expands the choice of methods and prompts fresh considerations with regard to instrumentation, data acquisition, and signal processing. In this review, the current status of short-<em>T</em>₂ MRI is surveyed. In an attempt to structure the growing range of techniques, the presentation highlights overarching concepts and basic methodological options. The most frequently used approaches are described in detail, including acquisition strategies, image reconstruction, hardware requirements, means of introducing contrast, sources of artifacts, limitations, and applications.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"114 ","pages":"Pages 237-270"},"PeriodicalIF":6.1,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.07.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47417733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SABRE: Chemical kinetics and spin dynamics of the formation of hyperpolarization","authors":"Danila A. Barskiy ,&nbsp;Stephan Knecht ,&nbsp;Alexandra V. Yurkovskaya ,&nbsp;Konstantin L. Ivanov","doi":"10.1016/j.pnmrs.2019.05.005","DOIUrl":"10.1016/j.pnmrs.2019.05.005","url":null,"abstract":"<div><p>In this review, we present the physical principles of the SABRE (Signal Amplification By Reversible Exchange) method. SABRE is a promising hyperpolarization technique that enhances NMR signals by transferring spin order from parahydrogen (an isomer of the H₂ molecule that is in a singlet nuclear spin state) to a substrate that is to be polarized. Spin order transfer takes place in a transient organometallic complex which binds both parahydrogen and substrate molecules; after dissociation of the SABRE complex, free hyperpolarized substrate molecules are accumulated in solution. An advantage of this method is that the substrate is not modified chemically, and its polarization can be regenerated multiple times by bubbling fresh parahydrogen through the solution. Thus, SABRE requires two key ingredients: (i) polarization transfer and (ii) chemical exchange of both parahydrogen and substrate. While there are several excellent reviews on applications of SABRE, the background of the method is discussed less frequently. In this review we aim to explain in detail how SABRE hyperpolarization is formed, focusing on key aspects of both spin dynamics and chemical kinetics, as well as on the interplay between them. Hence, we first cover the known spin order transfer methods applicable to SABRE — cross-relaxation, coherent spin mixing at avoided level crossings, and coherence transfer — and discuss their practical implementation for obtaining SABRE polarization in the most efficient way. Second, we introduce and explain the principle of SABRE hyperpolarization techniques that operate at ultralow (&lt;1 μT), at low (1μT to 0.1 T) and at high (&gt;0.1 T) magnetic fields. Finally, chemical aspects of SABRE are discussed in detail, including chemical systems that are amenable to SABRE and the exchange processes that are required for polarization formation. A theoretical treatment of the spin dynamics and their interplay with chemical kinetics is also presented. This review outlines known aspects of SABRE and provides guidelines for the design of new SABRE experiments, with the goal of solving practical problems of enhancing weak NMR signals.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"114 ","pages":"Pages 33-70"},"PeriodicalIF":6.1,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.05.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49064334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solid state NMR at very high temperatures","authors":"Holger Kirchhain,&nbsp;Leo van Wüllen","doi":"10.1016/j.pnmrs.2019.05.006","DOIUrl":"10.1016/j.pnmrs.2019.05.006","url":null,"abstract":"<div><p>Whereas high resolution NMR at temperatures up to 550 K can be routinely performed selecting from a variety of commercially available NMR hardware, experiments in the high temperature regime, defined here as T &gt; 550 K, have been restricted to just a few specialized laboratories. In this contribution we present important developments of high temperature NMR over the last decades. Various methods to achieve high resolution high temperature NMR, including resistive heating, laser-assisted heating and inductive heating, are presented and their specific advantages and disadvantages discussed. The various ways of temperature monitoring including the use of chemical shift thermometers or T₁ thermometers are reviewed. In the last section, some typical application examples from the field of oxidic glasses and melts are given.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"114 ","pages":"Pages 71-85"},"PeriodicalIF":6.1,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.05.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44960164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combination of illumination and high resolution NMR spectroscopy: Key features and practical aspects, photochemical applications, and new concepts","authors":"Philipp Nitschke ,&nbsp;Nanjundappa Lokesh ,&nbsp;Ruth M. Gschwind","doi":"10.1016/j.pnmrs.2019.06.001","DOIUrl":"10.1016/j.pnmrs.2019.06.001","url":null,"abstract":"&lt;div&gt;&lt;p&gt;In the last decade, photochemical and photocatalytic applications have developed into one of the dominant research fields in chemistry. However, mechanistic investigations to sustain this enormous progress are still relatively sparse and in high demand by the photochemistry community. UV/Vis spectroscopy and EPR spectroscopy have been the main spectroscopic tools to study the mechanisms of photoreactions due to their higher time resolution and sensitivity. On the other hand, application of NMR in photosystems has been mainly restricted to photo-CIDNP, since the initial photoexcitation was thought to be the single key to understand photoinduced reactions. In 2015 the Gschwind group showcased the possibility that different reaction pathways could occur from the same photoexcited state depending on the reaction conditions by using &lt;em&gt;in situ&lt;/em&gt; LED illumination NMR. This was the starting point to push the active participation of NMR in photosystems to its full potential, including reaction profiling, structure determination of intermediates, downstream mechanistic studies, dark pathways, intermediate sequencing with CEST etc. Following this, multiple studies using &lt;em&gt;in situ&lt;/em&gt; illumination NMR have been reported focusing on mechanistic investigations in photocatalysis, photoswitches, and polymerizations. The recent increased popularity of this technique can be attributed to the simplicity of the experimental setup and the availability of low cost, high power LEDs. Here, we review the development of experimental design, applications and new concepts of illuminated NMR. In the first part, we describe the development of different designs of NMR illumination apparatus, illuminating from the bottom/side/top/inside, and discuss their pros and cons for specific applications. Furthermore, we address LASERs and LEDs as different light sources as well as special cases such as UVNMR(-illumination), FlowNMR, NMR on a Chip etc. To complete the discussion on experimental apparatus, the advantages and disadvantages of &lt;em&gt;in situ&lt;/em&gt; LED illumination NMR versus &lt;em&gt;ex situ&lt;/em&gt; illumination NMR are described. The second part of this review discusses different facets of applications of inside illumination experiments. It highlights newly revealed mechanistic and structural information and ideas in the fields of photocatalyis, photoswitches and photopolymerization. Finally, we present new concepts and methods based on the combination of NMR and illumination such as sensitivity enhancement, chemical pump probes, experimental access to transition state combinations and NMR actinometry. Overall this review presents NMR spectroscopy as a complementary tool to UV/Vis spectroscopy in mechanistic and structural investigations of photochemical processes. The review is presented in a way that is intended to assist the photochemistry and photocatalysis community in adopting and understanding this astonishingly powerful &lt;em&gt;in situ&lt;/em&gt; LED illumination NMR met","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"114 ","pages":"Pages 86-134"},"PeriodicalIF":6.1,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2019.06.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41297324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}