Journal of Magnetic Resonance Open最新文献

{"title":"Understanding magnetic fields, for NMR/MRI","authors":"Mark S. Conradi","doi":"10.1016/j.jmro.2024.100158","DOIUrl":"10.1016/j.jmro.2024.100158","url":null,"abstract":"<div><p>The basic physics of magnetic fields is presented for a target audience of NMR workers. This group often does not have formal training in electromagnetism, but could benefit from an understanding of a <em>selected subset</em> of topics. The focus here is on a relatively non-mathematical view, intended to deliver an intuitive understanding of the topic. The covered topics start with the fields arising from simple idealized currents, including long straight wires, short flat coils, infinite current sheets, long solenoids, and magnetic dipole moments. The generation of field gradients and shim fields is discussed. All of these can be unified by considering the divergence and curl of the magnetic field. Magnetic materials are treated, both linear magnetizable materials (including the sample itself) and permanently magnetized materials; the approaches of equivalent currents and Ampere's theorem for magnetic circuits are presented.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"20 ","pages":"Article 100158"},"PeriodicalIF":2.624,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266644102400013X/pdfft?md5=5ee9eaa54dcb6dba86c4de3a544c31db&pid=1-s2.0-S266644102400013X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945612","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":"Fast quantitative MRI: Spiral Acquisition Matching-Based Algorithm (SAMBA) for Robust T1 and T2 Mapping","authors":"Mireia Perera-Gonzalez ,&nbsp;Christina J. MacAskill ,&nbsp;Heather A. Clark ,&nbsp;Chris A. Flask","doi":"10.1016/j.jmro.2024.100157","DOIUrl":"10.1016/j.jmro.2024.100157","url":null,"abstract":"<div><p>Conventional diagnostic images from Magnetic Resonance Imaging (MRI) are typically qualitative and require subjective interpretation. Alternatively, quantitative MRI (qMRI) methods have become more prevalent in recent years with multiple clinical and preclinical imaging applications. Quantitative MRI studies on preclinical MRI scanners are being used to objectively assess tissues and pathologies in animal models and to evaluate new molecular MRI contrast agents. Low-field preclinical MRI scanners (<span><math><mo>≤</mo></math></span>3.0T) are particularly important in terms of evaluating these new MRI contrast agents at human MRI field strengths. Unfortunately, these low-field preclinical qMRI methods are challenged by long acquisition times, intrinsically low MRI signal levels, and susceptibility to motion artifacts. In this study, we present a new rapid qMRI method for a preclinical 3.0T MRI scanner that combines a Spiral Acquisition with a Matching-Based Algorithm (SAMBA) to rapidly and quantitatively evaluate MRI contrast agents. In this initial development, we compared SAMBA with gold-standard Spin Echo MRI methods using Least Squares Fitting (SELSF) in vitro phantoms and demonstrated shorter scan times without compromising measurement accuracy or repeatability. These initial results will pave the way for future in vivo qMRI studies using state-of-the-art chemical probes.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"20 ","pages":"Article 100157"},"PeriodicalIF":2.624,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000128/pdfft?md5=6a04edfdeeca12220ce76d49dd902c23&pid=1-s2.0-S2666441024000128-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963223","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":"Automated hyperpolarized 129Xe gas generator for nuclear magnetic resonance spectroscopy and imaging applications","authors":"Mineyuki Hattori ,&nbsp;Takashi Hiraga ,&nbsp;Kazuhiro Homma ,&nbsp;Norio Ohtake","doi":"10.1016/j.jmro.2024.100154","DOIUrl":"https://doi.org/10.1016/j.jmro.2024.100154","url":null,"abstract":"<div><p>We describe a method and an apparatus for producing hyperpolarized (HP) Xe gas of high concentration without Xe condensation. The HP Xe generator works under atmospheric pressure and employs a quasi-continuous method to provide a continuous supply of HP Xe gas by adopting technologies for supplying a highly pure gas, a gas control system and precise pressure control. The apparatus has a glass cell containing solid Rb metal and solid Xe in vacuum at a low temperature and is heated so that the Xe becomes a gas and Rb exists in a gas-liquid mixture. Then a magnetic field is applied with laser beam irradiation to produce polarized Xe gas of high concentration. The device was evaluated using a 2T magnetic resonance imaging (MRI) scanner. Long-term experimental operation demonstrated the continuous collection of 30 ml syringes of HP Xe gas with a sufficient polarization rate for fast one scan acquisition. A practical device for the automated manufacture of HP ¹²⁹Xe gas was thus successfully developed.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"20 ","pages":"Article 100154"},"PeriodicalIF":2.624,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000098/pdfft?md5=b9d93058d60dbb47913e59da366288d6&pid=1-s2.0-S2666441024000098-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583180","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 comprehensive solid-state NMR and theoretical modeling study to reveal the structural evolution of layered yttrium hydroxide upon calcination","authors":"Yanxin Liu ,&nbsp;Xinyue Sheng ,&nbsp;Hui Ding,&nbsp;Jun Xu","doi":"10.1016/j.jmro.2024.100155","DOIUrl":"https://doi.org/10.1016/j.jmro.2024.100155","url":null,"abstract":"<div><p>Layered rare earth hydroxides (LREHs) are a new family of ion-exchangeable layered metal hydroxides, which have extensive applications in various fields due to the unique properties of rare earth cations in the layered structure and the anion exchange capacity. The transformation of layered metal hydroxides to new layered phases that can be restored through the memory effect is critical for their chemistry and applications. However, the structure details of these new phases such as the coordination environments of rare earth cations/counterions and their evolution as a function of calcination temperature remain unclear to date. Herein, a comprehensive ⁸⁹Y/³⁵Cl solid-state NMR (ssNMR) and theoretical modeling approach was used to reveal the structural evolution of a representative LREH, namely LYH-Cl, upon calcination. We first identified partial decomposition products of Y₃O(OH)₅Cl₂ and Y(OH)₃ during the dehydration stage, then uncovered the preferential removal of hydroxide ions on yttrium sites coordinated with chlorine during the dehydroxylation stage, and finally determined the preferential removal of chlorine exposed to the surface of layers during the dechlorination stage. The coordination environments of Y³⁺ and Cl⁻ undergo significant changes upon calcination, revealed by ssNMR experiments. These findings thus help us to overcome the obstacles impeding the rational design and synthesis of LREH-based functional materials via memory effect, underscoring the vast potential of ssNMR in deepening the understanding of layered metal hydroxides and related materials.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"20 ","pages":"Article 100155"},"PeriodicalIF":2.624,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000104/pdfft?md5=287c5bd3157fdc6d9649443e59ae270a&pid=1-s2.0-S2666441024000104-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141303279","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 practical introduction to radio frequency electronics for NMR probe builders","authors":"Jose L. Uribe ,&nbsp;Rachel W. Martin","doi":"10.1016/j.jmro.2024.100153","DOIUrl":"10.1016/j.jmro.2024.100153","url":null,"abstract":"<div><p>In this tutorial paper, we describe some basic principles and practical considerations for designing probe circuits for NMR or MRI. The goal is building a bridge from material that is familiar from undergraduate physics courses to more specialized information needed to put together and tune a resonant circuit for magnetic resonance. After a brief overview of DC and AC circuits, we discuss the properties of circuit elements used in an NMR probe and how they can be assembled into building blocks for multi-channel circuits. We also discuss the use of transmission lines as circuit elements as well as practical considerations for improving circuit stability and power handling.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"19 ","pages":"Article 100153"},"PeriodicalIF":2.624,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000086/pdfft?md5=e764d087c8c9589e2032d9c0b4e45ecc&pid=1-s2.0-S2666441024000086-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141130345","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":"Biradicals based on PROXYL containing building blocks for efficient dynamic nuclear polarization in biotolerant media","authors":"Kevin Herr ,&nbsp;Mark V. Höfler ,&nbsp;Henrike Heise ,&nbsp;Fabien Aussenac ,&nbsp;Felix Kornemann ,&nbsp;David Rosenberger ,&nbsp;Martin Brodrecht ,&nbsp;Marcos de Oliveira Jr. ,&nbsp;Gerd Buntkowsky ,&nbsp;Torsten Gutmann","doi":"10.1016/j.jmro.2024.100152","DOIUrl":"https://doi.org/10.1016/j.jmro.2024.100152","url":null,"abstract":"<div><p>A versatile strategy for synthesizing tailored peptide based biradicals is presented. By labeling the protected amino acid hydroxyproline with PROXYL via the OH functionality and using this building block in solid phase peptide synthesis (SPPS), the obtained peptides become polarization agents for DNP enhanced solid-state NMR in biotolerant media. To analyze the effect of the radical position on the enhancement factor, three different biradicals are synthesized. The PROXYL spin-label is inserted in a collagen inspired artificial peptide sequence by binding through the OH group of the hydroxyproline moieties at specific position in the chain. This labeling strategy is universally applicable for any hydroxyproline position in a peptide sequence since solid-phase peptide synthesis is used to insert the building block. High performance liquid chromatography (HPLC) and mass spectrometry (MS) analyses show the successful introduction of the spin label in the peptide chain and electron paramagnetic resonance (EPR) spectroscopy confirms its activity. Dynamic nuclear polarization (DNP) enhanced solid-state nuclear magnetic resonance (NMR) experiments performed on frozen aqueous glycerol-d₈ solutions containing these peptide radicals show significantly higher enhancement factors of up to 45 in ¹H→¹³C cross polarization magic angle spinning (CP MAS) experiments compared to an analogous mono-radical peptide including this building block (ε ≈ 14). Compared to commercial biradicals such as AMUPol for which enhancement factors &gt; 100 have been obtained in the past and which have been optimized in their structure, the obtained enhancement up to 45 for our biradicals presents a significant progress in radical design.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"20 ","pages":"Article 100152"},"PeriodicalIF":2.624,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000074/pdfft?md5=9edd42ec4ece71ac05f76ff326cdb2fa&pid=1-s2.0-S2666441024000074-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141325079","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 statistical learning framework for mapping indirect measurements of ergodic systems to emergent properties","authors":"Nicholas Hindley ,&nbsp;Stephen J. DeVience ,&nbsp;Ella Zhang ,&nbsp;Leo L. Cheng ,&nbsp;Matthew S. Rosen","doi":"10.1016/j.jmro.2024.100151","DOIUrl":"https://doi.org/10.1016/j.jmro.2024.100151","url":null,"abstract":"<div><p>The discovery of novel experimental techniques often lags behind contemporary theoretical understanding. In particular, it can be difficult to establish appropriate measurement protocols without analytic descriptions of the underlying system-of-interest. Here we propose a statistical learning framework that avoids the need for such descriptions for ergodic systems. We validate this framework by using Monte Carlo simulation and deep neural networks to learn a mapping between nuclear magnetic resonance spectra acquired on a novel low-field instrument and proton exchange rates in ethanol-water mixtures. We found that trained networks exhibited normalized-root-mean-square errors of less than 1 % for exchange rates under 150 s⁻¹ but performed poorly for rates above this range. This differential performance occurred because low-field measurements are indistinguishable from one another for fast exchange. Nonetheless, where a discoverable relationship between indirect measurements and emergent dynamics exists, we demonstrate the possibility of approximating it in an efficient, data-driven manner.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"19 ","pages":"Article 100151"},"PeriodicalIF":2.624,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000062/pdfft?md5=ebd7d5b1fe87c839cb035aefb252dc6b&pid=1-s2.0-S2666441024000062-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140822286","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":"Water suppression 101 for benchtop NMR–An accessible guide and primer including fully interactive training videos","authors":"Ronald Soong ,&nbsp;William Wolff ,&nbsp;Jacob Pellizzari ,&nbsp;Katelyn Downey ,&nbsp;Sarah Chen ,&nbsp;Rajshree Ghosh Biswas ,&nbsp;Monica Bastawrous ,&nbsp;Benjamin Goerling ,&nbsp;Venita Busse ,&nbsp;Falko Busse ,&nbsp;Colin Elliott ,&nbsp;Agnes Haber ,&nbsp;Alain Belguise ,&nbsp;Myrna Simpson ,&nbsp;Andre Simpson","doi":"10.1016/j.jmro.2024.100150","DOIUrl":"https://doi.org/10.1016/j.jmro.2024.100150","url":null,"abstract":"<div><p>Benchtop NMR is enjoying a renaissance with numerous manufacturers bringing products to the market over the last decade. The improved accessibility, lower cost of ownership and ease of use (vs high field NMR), is attracting new users into NMR spectroscopy, which is highly beneficial for the field in general. As benchtop NMR systems seldom require deuterated solvents, this allows samples to be analyzed “as is”, without extraction or alteration. However, many interesting samples, be it an organic reaction mixture, beer, or a biofluid, contain one or more solvent/water signals, which often require suppression. Due to the lower spectral dispersion of benchtop NMR's (vs high field) the frequency of solvent/water is much closer to the analytes of interest, making solvent suppression more challenging. As such, there is a conundrum, where novel users wish to analyze unaltered samples but are quickly faced with the challenge of water suppression, and the wealth of options in the high field literature can be overwhelming. It is important to note that all manufacturers offer some sort of automated water suppression that can be performed with a “single click” that are sufficient for “walk-up” applications or occasional users. This primer is aimed as an accessible guide to those wishing to take the next step and is suitable for users who; 1) would like to pick the optimal water suppression approach for their sample type and 2) wish to understand how water suppression works. The guide focuses on water suppression approaches that are easy to apply, namely presaturation based sequences, binomial sequences for aggressive suppression, and WET for multiple signal suppression, across a range of samples including sucrose standards, espresso, human blood serum and wine. The primer finishes with a flow chart that can be used to guide users in choosing the optimal water suppression approach for their specific sample type, with considerations, including exchangeable signals and the preservation of macromolecular signals, amongst others. In addition, the primer includes 3 fully interactive videos based on H5P technology, focusing on how to acquire data using the approaches described here. The videos include quizzes, with a first-person-perspective of the spectrometer software with interactive elements, as if the users were acquiring the data themselves. In summary, the primer is aimed at advanced undergraduates, graduate students, new users, or users wishing to expand their water/solvent suppression skills/knowledge using benchtop NMR.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"19 ","pages":"Article 100150"},"PeriodicalIF":2.624,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000050/pdfft?md5=b2a9acb37ab142c6d9bcdc7a19c13e74&pid=1-s2.0-S2666441024000050-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140558220","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":"SABRE-hyperpolarization dynamics of [1-13C]pyruvate monitored by in situ zero- to ultra-low field NMR","authors":"Adam Ortmeier ,&nbsp;Keilian MacCulloch ,&nbsp;Danila A. Barskiy ,&nbsp;Nicolas Kempf ,&nbsp;John Z Myers ,&nbsp;Rainer Körber ,&nbsp;Andrey N Pravdivtsev ,&nbsp;Kai Buckenmaier ,&nbsp;Thomas Theis","doi":"10.1016/j.jmro.2024.100149","DOIUrl":"https://doi.org/10.1016/j.jmro.2024.100149","url":null,"abstract":"<div><p>Hyperpolarized [1–¹³C]pyruvate is the leading metabolite used in the emerging field of hyperpolarization-enhanced MRI. Signal amplification by reversible exchange (SABRE) is a straight forward hyperpolarization method that has recently been shown to hyperpolarize [1–¹³C]pyruvate at low (microtesla and below) magnetic fields. Here, we show that commercial optical magnetometers with Rb-vapor media can be used to readily monitor the build-up and decay of the hyperpolarized MR signal. In addition, we measure ZULF-NMR spectra in various conditions, ranging from a <em>J</em>-coupling-dominated regime transitioning into a Zeeman-dominated regime when going from a sub-nT field to a µT field. The experimentally acquired spectra are matched well by numerical simulations.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"19 ","pages":"Article 100149"},"PeriodicalIF":2.624,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000049/pdfft?md5=7e68f1c08d02e208bd9c716be41d5efb&pid=1-s2.0-S2666441024000049-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140539223","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":"The generalized Ernst angle","authors":"Ole W. Sørensen","doi":"10.1016/j.jmro.2024.100148","DOIUrl":"10.1016/j.jmro.2024.100148","url":null,"abstract":"<div><p>Though the Ernst angle concept presented in the original paper introducing Fourier NMR spectroscopy was developed for sensitivity optimization in a time-averaged single-pulse experiment it is shown here that its conclusions may be generalized to complex multidimensional experiments. The salient message is to explore (re-)design of NMR pulse sequences to return some of the magnetization to the z axis at the end, so that they can be performed without a relaxation delay. In favorable cases, such pulse sequences can be concatenated in a synergistic way to further enhance sensitivity.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"19 ","pages":"Article 100148"},"PeriodicalIF":2.624,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000037/pdfft?md5=02d1269ff097785256cb6ce2f4b9ad92&pid=1-s2.0-S2666441024000037-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140150329","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}