Progress in Nuclear Magnetic Resonance Spectroscopy最新文献_第7页

Symmetry versus entropy: Long-lived states and coherences 对称与熵:长期存在的状态和一致性

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2021-02-01 DOI: 10.1016/j.pnmrs.2020.12.002

Florin Teleanu , Aude Sadet , Paul R. Vasos

{"title":"Symmetry versus entropy: Long-lived states and coherences","authors":"Florin Teleanu , Aude Sadet , Paul R. Vasos","doi":"10.1016/j.pnmrs.2020.12.002","DOIUrl":"10.1016/j.pnmrs.2020.12.002","url":null,"abstract":"<div><p>In recent years, new molecular symmetry-based approaches for magnetic resonance have been invented. The implications of these discoveries will be significant for molecular imaging via magnetic resonance, <em>in vitro</em> as well as <em>in vivo</em>, for quantum computing and for other fields. Since the initial observation in 2004 in Southampton that effective spin symmetry can be instilled in a molecule during magnetic resonance experiments, spin states that are resilient to relaxation mechanisms have been increasingly used. Most of these states are related to the nuclear singlet in a pair of <em>J</em>-coupled spins. Tailored relaxation rate constants for magnetization became available in molecules of different sizes and structures, as experimental developments broadened the scope of symmetry-adapted spin states. The ensuing access to timescales longer than the classically-attained ones by circa one order of magnitude allows the study of processes such as slow diffusion or slow exchange that were previously beyond reach. Long-lived states formed by differences between populations of singlets and triplets have overcome the limitations imposed by longitudinal relaxation times (<em>T<sub>1</sub></em>) by factors up to 40. Long-lived coherences formed by superpositions of singlets and triplets have overcome the limit of classical transverse coherence (<em>T<sub>2</sub></em>) by a factor 9. We present here an overview of the development and applications of long-lived states (LLS) and long-lived coherences (LLC’s) and considerations on future perspectives.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"122 ","pages":"Pages 63-75"},"PeriodicalIF":6.1,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2020.12.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25405552","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}

引用次数: 5

Cardiac magnetic resonance fingerprinting: Trends in technical development and potential clinical applications 心脏磁共振指纹识别:技术发展趋势和潜在临床应用

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2021-02-01 DOI: 10.1016/j.pnmrs.2020.10.001

Brendan L. Eck , Scott D. Flamm , Deborah H. Kwon , W.H. Wilson Tang , Claudia Prieto Vasquez , Nicole Seiberlich

{"title":"Cardiac magnetic resonance fingerprinting: Trends in technical development and potential clinical applications","authors":"Brendan L. Eck , Scott D. Flamm , Deborah H. Kwon , W.H. Wilson Tang , Claudia Prieto Vasquez , Nicole Seiberlich","doi":"10.1016/j.pnmrs.2020.10.001","DOIUrl":"10.1016/j.pnmrs.2020.10.001","url":null,"abstract":"<div><p>Quantitative cardiac magnetic resonance has emerged in recent years as an approach for evaluating a range of cardiovascular conditions, with T<sub>1</sub> and T<sub>2</sub> mapping at the forefront of these developments. Cardiac Magnetic Resonance Fingerprinting (cMRF) provides a rapid and robust framework for simultaneous quantification of myocardial T<sub>1</sub> and T<sub>2</sub> in addition to other tissue properties. Since the advent of cMRF, a number of technical developments and clinical validation studies have been reported. This review provides an overview of cMRF, recent technical developments, healthy subject and patient studies, anticipated technical improvements, and potential clinical applications. Recent technical developments include slice profile and pulse efficiency corrections, improvements in image reconstruction, simultaneous multislice imaging, 3D whole-ventricle imaging, motion-resolved imaging, fat–water separation, and machine learning for rapid dictionary generation. Future technical developments in cMRF, such as B<sub>0</sub> and B<sub>1</sub> field mapping, acceleration of acquisition and reconstruction, imaging of patients with implanted devices, and quantification of additional tissue properties are also described. Potential clinical applications include characterization of infiltrative, inflammatory, and ischemic cardiomyopathies, tissue characterization in the left atrium and right ventricle, post-cardiac transplantation assessment, reduction of contrast material, pre-procedural planning for electrophysiology interventions, and imaging of patients with implanted devices.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"122 ","pages":"Pages 11-22"},"PeriodicalIF":6.1,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2020.10.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25405551","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}

引用次数: 7

In vivo methods and applications of xenon-129 magnetic resonance 氙-129磁共振的体内方法及应用

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2021-02-01 DOI: 10.1016/j.pnmrs.2020.11.002

Helen Marshall, Neil J. Stewart, Ho-Fung Chan, Madhwesha Rao, Graham Norquay, Jim M. Wild

{"title":"In vivo methods and applications of xenon-129 magnetic resonance","authors":"Helen Marshall, Neil J. Stewart, Ho-Fung Chan, Madhwesha Rao, Graham Norquay, Jim M. Wild","doi":"10.1016/j.pnmrs.2020.11.002","DOIUrl":"10.1016/j.pnmrs.2020.11.002","url":null,"abstract":"<div><p>Hyperpolarised gas lung MRI using xenon-129 can provide detailed 3D images of the ventilated lung airspaces, and can be applied to quantify lung microstructure and detailed aspects of lung function such as gas exchange. It is sensitive to functional and structural changes in early lung disease and can be used in longitudinal studies of disease progression and therapy response. The ability of <sup>129</sup>Xe to dissolve into the blood stream and its chemical shift sensitivity to its local environment allow monitoring of gas exchange in the lungs, perfusion of the brain and kidneys, and blood oxygenation. This article reviews the methods and applications of <em>in vivo</em> <sup>129</sup>Xe MR in humans, with a focus on the physics of polarisation by optical pumping, radiofrequency coil and pulse sequence design, and the <em>in vivo</em> applications of <sup>129</sup>Xe MRI and MRS to examine lung ventilation, microstructure and gas exchange, blood oxygenation, and perfusion of the brain and kidneys.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"122 ","pages":"Pages 42-62"},"PeriodicalIF":6.1,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2020.11.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25405555","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}

引用次数: 26

Covariance NMR: Theoretical concerns, practical considerations, contemporary applications and related techniques 协方差核磁共振:理论问题，实际考虑，当代应用和相关技术

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2021-02-01 DOI: 10.1016/j.pnmrs.2020.09.001

David A. Snyder

引用次数: 8

Isotope effects on chemical shifts in the study of hydrogen bonded biological systems 氢键生物系统研究中同位素对化学位移的影响

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2020-10-01 DOI: 10.1016/j.pnmrs.2020.08.001

Poul Erik Hansen

引用次数: 4

Relaxivity of manganese ferrite nanoparticles 铁酸锰纳米颗粒的弛豫率

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2020-10-01 DOI: 10.1016/j.pnmrs.2020.07.002

Joop A. Peters

引用次数: 15

NMR-based isotopic and isotopomic analysis 基于核磁共振的同位素和同位素分析

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2020-10-01 DOI: 10.1016/j.pnmrs.2020.07.001

Serge Akoka, Gérald S. Remaud

{"title":"NMR-based isotopic and isotopomic analysis","authors":"Serge Akoka, Gérald S. Remaud","doi":"10.1016/j.pnmrs.2020.07.001","DOIUrl":"10.1016/j.pnmrs.2020.07.001","url":null,"abstract":"<div><p>Molecules exist in different isotopic compositions and most of the processes, physical or chemical, in living systems cause selection between heavy and light isotopes. Thus, knowing the isotopic fractionation of the common atoms, such as H, C, N, O or S, at each step during a metabolic pathway allows the construction of a unique isotope profile that reflects its past history. Having access to the isotope abundance gives valuable clues about the (bio)chemical origin of biological or synthetic molecules. Whereas the isotope ratio measured by mass spectrometry provides a global isotope composition, quantitative NMR measures isotope ratios at individual positions within a molecule. We present here the requirements and the corresponding experimental strategies to use quantitative NMR for measuring intramolecular isotope profiles. After an introduction showing the historical evolution of NMR for measuring isotope ratios, the vocabulary and symbols – for describing the isotope content and quantifying its change – are defined. Then, the theoretical framework of very accurate quantitative NMR is presented as the principle of Isotope Ratio Measurement by NMR spectroscopy, including the practical aspects with nuclei other than <sup>2</sup>H, that have been developed and employed to date. Lastly, the most relevant applications covering three issues, tackling counterfeiting, authentication, and forensic investigation, are presented, before giving some perspectives combining technical improvements and methodological approaches.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"120 ","pages":"Pages 1-24"},"PeriodicalIF":6.1,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2020.07.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38610277","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}

引用次数: 21

Manipulating beams of paramagnetic atoms and molecules using inhomogeneous magnetic fields 利用不均匀磁场操纵顺磁性原子和分子束

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2020-10-01 DOI: 10.1016/j.pnmrs.2020.08.002

Paul Jansen, Frédéric Merkt

引用次数: 7

Pulse sequences for measuring exchange rates between proton species: From unlocalised NMR spectroscopy to chemical exchange saturation transfer imaging 用于测量质子之间交换速率的脉冲序列:从非局部核磁共振波谱到化学交换饱和转移成像

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2020-10-01 DOI: 10.1016/j.pnmrs.2020.06.001

Eleni Demetriou, Aaron Kujawa, Xavier Golay

{"title":"Pulse sequences for measuring exchange rates between proton species: From unlocalised NMR spectroscopy to chemical exchange saturation transfer imaging","authors":"Eleni Demetriou, Aaron Kujawa, Xavier Golay","doi":"10.1016/j.pnmrs.2020.06.001","DOIUrl":"10.1016/j.pnmrs.2020.06.001","url":null,"abstract":"<div><p>Within the field of NMR spectroscopy, the study of chemical exchange processes through saturation transfer techniques has a long history. In the context of MRI, chemical exchange techniques have been adapted to increase the sensitivity of imaging to small fractions of exchangeable protons, including the labile protons of amines, amides and hydroxyls. The MR contrast is generated by frequency-selective irradiation of the labile protons, which results in a reduction of the water signal associated with transfer of the labile protons’ saturated magnetization to the protons of the surrounding free water. The signal intensity depends on the rate of chemical exchange and the concentration of labile protons as well as on the properties of the irradiation field. This methodology is referred to as CEST (chemical exchange saturation transfer) imaging. Applications of CEST include imaging of molecules with short transverse relaxation times and mapping of physiological parameters such as pH, temperature, buffer concentration and chemical composition due to the dependency of this chemical exchange effect on all these parameters. This article aims to describe these effects both theoretically and experimentally. In depth analysis and mathematical modelling are provided for all pulse sequences designed to date to measure the chemical exchange rate. Importantly, it has become clear that the background signal from semi-solid protons and the presence of the Nuclear Overhauser Effect (NOE), either through direct dipole-dipole mechanisms or through exchange-relayed signals, complicates the analysis of CEST effects. Therefore, advanced methods to suppress these confounding factors have been developed, and these are also reviewed. Finally, the experimental work conducted both <em>in vitro</em> and <em>in vivo</em> is discussed and the progress of CEST imaging towards clinical practice is presented.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"120 ","pages":"Pages 25-71"},"PeriodicalIF":6.1,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2020.06.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38610282","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}

引用次数: 5

Contemporary approaches to high-field magnetic resonance imaging with large field inhomogeneity 大场非均匀性高场磁共振成像的当代方法

IF 6.1 2区化学

Progress in Nuclear Magnetic Resonance Spectroscopy Pub Date : 2020-10-01 DOI: 10.1016/j.pnmrs.2020.07.003

Michael Mullen, Michael Garwood

{"title":"Contemporary approaches to high-field magnetic resonance imaging with large field inhomogeneity","authors":"Michael Mullen, Michael Garwood","doi":"10.1016/j.pnmrs.2020.07.003","DOIUrl":"10.1016/j.pnmrs.2020.07.003","url":null,"abstract":"<div><p>Despite its importance as a clinical imaging modality, magnetic resonance imaging remains inaccessible to most of the world’s population due to its high cost and infrastructure requirements. Substantial effort is underway to develop portable, low-cost systems able to address MRI access inequality and to enable new uses of MRI such as bedside imaging. A key barrier to development of portable MRI systems is increased magnetic field inhomogeneity when using small polarizing magnets, which degrades image quality through distortions and signal dropout. Many approaches address field inhomogeneity by using a low polarizing field, approximately ten to hundreds of milli-Tesla. At low-field, even a large relative field inhomogeneity of several thousand parts-per-million (ppm) results in resonance frequency dispersion of only 1–2 kHz. Under these conditions, with necessarily wide pulse bandwidths, fast spin-echo sequences may be used at low field with negligible subject heating, and a broad range of other available imaging sequences can be implemented. However, high-field MRI, 1.5 T or greater, can provide substantially improved signal-to-noise ratio and image contrast, so that higher spatial resolution, clinical quality images may be acquired in significantly less time than is necessary at low-field. The challenge posed by small, high-field systems is that the relative field inhomogeneity, still thousands of ppm, becomes tens of kilohertz over the imaging volume. This article describes the physical consequences of field inhomogeneity on established gradient- and spin-echo MRI sequences, and suggests ways to reduce signal dropout and image distortion from field inhomogeneity. Finally, the practicality of currently available image contrasts is reviewed when imaging with a high magnetic field with large inhomogeneity.</p></div>","PeriodicalId":20740,"journal":{"name":"Progress in Nuclear Magnetic Resonance Spectroscopy","volume":"120 ","pages":"Pages 95-108"},"PeriodicalIF":6.1,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.pnmrs.2020.07.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38610286","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}

引用次数: 9