Journal of Magnetic Resonance Open最新文献

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23Na intermolecular multiple-quantum coherences in salt solutions 盐溶液中的23Na分子间多量子相干性
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2025-01-20 DOI: 10.1016/j.jmro.2025.100186
Haoyu Li , Yifan Song , Yu Yin , Juntao Xia , Yun Chen , Maria Grazia Concilio , Xueqian Kong
{"title":"23Na intermolecular multiple-quantum coherences in salt solutions","authors":"Haoyu Li ,&nbsp;Yifan Song ,&nbsp;Yu Yin ,&nbsp;Juntao Xia ,&nbsp;Yun Chen ,&nbsp;Maria Grazia Concilio ,&nbsp;Xueqian Kong","doi":"10.1016/j.jmro.2025.100186","DOIUrl":"10.1016/j.jmro.2025.100186","url":null,"abstract":"<div><div>The phenomenon of intermolecular multiple-quantum coherences (iMQCs) has been known for decades, mainly for spin-1/2 nuclei. However, the iMQC of <sup>23</sup>Na, a spin-3/2 quadrupolar nucleus, has not been studied previously. In this communication, we report the observation of <sup>23</sup>Na iMQC signals arising from <sup>23</sup>Na–<sup>23</sup>Na long-range dipolar interaction in the aqueous solutions of various sodium salts. We investigated the iMQC signal in response to different experimental parameters. We also formulated a theoretical model to explain the experimental results. Since sodium ions play important roles in biology and industry, <sup>23</sup>Na iMQC experiments could bring new insights into ion dynamics and interactions in solutions.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"22 ","pages":"Article 100186"},"PeriodicalIF":2.624,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387344","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}
引用次数: 0
Developing hyperpolarized metabolic contrast agents at high field dDNP for large animal research 大动物实验高场dDNP超极化代谢造影剂的研制
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-12-27 DOI: 10.1016/j.jmro.2024.100184
Ditte B. Christensen , Ingeborg S. Skre , Jan Henrik Ardenkjær-Larsen, Magnus Karlsson, Mathilde H. Lerche
{"title":"Developing hyperpolarized metabolic contrast agents at high field dDNP for large animal research","authors":"Ditte B. Christensen ,&nbsp;Ingeborg S. Skre ,&nbsp;Jan Henrik Ardenkjær-Larsen,&nbsp;Magnus Karlsson,&nbsp;Mathilde H. Lerche","doi":"10.1016/j.jmro.2024.100184","DOIUrl":"10.1016/j.jmro.2024.100184","url":null,"abstract":"<div><div>Dissolution Dynamic Nuclear Polarization (dDNP) polarizers have achieved high field strengths and large sample volumes. These advancements necessitate new formulations of hyperpolarized metabolic contrast agents (HMCAs) to enable large animal studies. While several metabolic substrates have been investigated at lower field dDNP and tested as HMCAs in rodents, <sup>13</sup>C-labeled pyruvate remains the most studied HMCA and is currently the only one actively used in clinical trials due to its favorable biological and physical properties. Effective human and large animal dDNP formulations require high molar substrate concentrations, low DNP sample viscosity for efficient dissolution, and adequate dilution of the DNP sample to minimize signal decay and maximize HMCA concentration.</div><div>We present substrate formulations optimized for high-field polarization and large-volume dissolution. Specifically, we validate the upscaling of [1–<sup>13</sup>C]pyruvate under high-field conditions and demonstrate that [1–<sup>13</sup>C]2-keto-isocaproate and [1,4–<sup>13</sup>C<sub>2</sub>]fumarate, which have been proven successful in rodent studies, can be formulated to yield high polarization at suitable concentrations and volumes for large animal metabolic MR imaging.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"22 ","pages":"Article 100184"},"PeriodicalIF":2.624,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164938","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}
引用次数: 0
Assessing a hyperpolarized [1-13C]-labeled alanine derivative enhanced via parahydrogen for in vivo studies 通过对氢增强超极化[1-13C]标记的丙氨酸衍生物的体内研究
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-12-20 DOI: 10.1016/j.jmro.2024.100183
Lisa M. Fries , Denis Moll , Ruhuai Mei , Theresa L․ K․ Hune , Josef Elsaßer , Stefan Glöggler
{"title":"Assessing a hyperpolarized [1-13C]-labeled alanine derivative enhanced via parahydrogen for in vivo studies","authors":"Lisa M. Fries ,&nbsp;Denis Moll ,&nbsp;Ruhuai Mei ,&nbsp;Theresa L․ K․ Hune ,&nbsp;Josef Elsaßer ,&nbsp;Stefan Glöggler","doi":"10.1016/j.jmro.2024.100183","DOIUrl":"10.1016/j.jmro.2024.100183","url":null,"abstract":"<div><div>Magnetic Resonance Imaging (MRI) is a valuable non-invasive technique widely used in clinical diagnostics; however, its sensitivity is limited, posing challenges in various medical conditions. Hyperpolarization techniques represent a promising approach to dramatically enhance signals in magnetic resonance imaging (MRI) and allow the use endogenous metabolites as contrast media. In this study, we synthesized N-acetyl-alanine ethyl ester as a novel imaging agent and assessed its <em>in vivo</em> imaging capabilities, potentially offering diagnostic and monitoring capabilities for cardiovascular diseases. It is derived from N-acetyl-alanine, an endogenous metabolic end product of protein degradation. The <em>in vivo</em> experiments resulted in high-resolution images of the circulatory system acquired within sub-seconds. Our findings not only highlight the potential preclinical utility of this new, generally available agent, but also advance the frontier of hyperpolarized contrast agents.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"22 ","pages":"Article 100183"},"PeriodicalIF":2.624,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164181","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}
引用次数: 0
Unveiling the impact of second-order 1H-17O Quadrupolar-Dipolar interaction on solid-state NMR spectroscopy 揭示二级1H-17O四极-偶极相互作用对固体核磁共振波谱的影响
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-12-10 DOI: 10.1016/j.jmro.2024.100182
Yi Ji , Kuizhi Chen , Aijing Hao , Guangjin Hou
{"title":"Unveiling the impact of second-order 1H-17O Quadrupolar-Dipolar interaction on solid-state NMR spectroscopy","authors":"Yi Ji ,&nbsp;Kuizhi Chen ,&nbsp;Aijing Hao ,&nbsp;Guangjin Hou","doi":"10.1016/j.jmro.2024.100182","DOIUrl":"10.1016/j.jmro.2024.100182","url":null,"abstract":"<div><div>Recent advances in the <sup>17</sup>O-enrichment techiques and high-resolution nuclear magnetic resonance (NMR) methods have opened new opportunities to utilize <sup>17</sup>O NMR to disentangle the zeolitic structure−property relationship that has not been well resolved through traditional <sup>1</sup>H, <sup>27</sup>Al, and <sup>29</sup>Si NMR spectroscopy. Compared with one-dimensional <sup>17</sup>O magic angle spinning (MAS) NMR experiments, <sup>1</sup>H-<sup>17</sup>O correlation spectrocopy has become a crucial method for revealing the structures and dynamics of reactive hydroxyl species in zeolites with higher resolution and precision. However, the introduction of <sup>17</sup>O can induce changes in <sup>1</sup>H MAS NMR signals due to the second-order <sup>1</sup>H-<sup>17</sup>O quadrupolar-dipolar (2nd-QD) cross interaction, which has recently been revealed by us on H-ZSM-5 (H-MFI) zeolites with 10-membered-ring (MR) channels. Herein, we performed various <sup>1</sup>H-<sup>17</sup>O correlation experiments (<sup>1</sup>H{<sup>17</sup>O}-<em>J</em>-heteronuclear multiple quantum coherence (HMQC), <sup>1</sup>H{<sup>17</sup>O}-<em>D</em>-HMQC, and <sup>1</sup>H→<sup>17</sup>O-<span><em>D</em></span>-RINEPT) on two other types of <sup>17</sup>O-enriched zeolites, i.e., H-Mordenite (H-MOR) with 8-/12-MR channels and H-ZSM-35 (H-FER) with 8-/10-MR channels. Notably, unusual <sup>1</sup>H-<sup>17</sup>O correlation signals with tilted patterns and magnetic-field-dependent shifts were observed on both samples and all tested correlation experiments at high fields up to 18.8 T. These observations were further comprehensively explained by theoretical analysis of the <sup>1</sup>H-<sup>17</sup>O quadrupolar-dipolar interaction, thus demonstrating that the <sup>1</sup>H-<sup>17</sup>O 2nd-QD interaction generally affects the <sup>1</sup>H and <sup>1</sup>H-<sup>17</sup>O correlation MAS NMR spectra of the dehydrated <sup>17</sup>O-enriched zeolites, irrespective of the framework types. Beyond zeolites, the non-ignorable 2nd-QD interaction on NMR spectroscopy can complicate NMR identification of <sup>17</sup>O-labeled hydroxyls in many other inorganic materials and biomolecules. The analysis methods proposed in this study are expected to effectively address these challenges and provide clearer insights into such systems.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"22 ","pages":"Article 100182"},"PeriodicalIF":2.624,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164180","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}
引用次数: 0
Hyperpolarized 129Xe for benchtop NMR: Inline instrumentation for automated yet flexible operation yielding high polarization 用于台式核磁共振的超极化129Xe:内联仪器,用于自动化但灵活的操作,产生高极化
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-12-10 DOI: 10.1016/j.jmro.2024.100179
Wolfgang Kilian , Samira Gulich , Thomas Riemer , Lorenz Mitschang
{"title":"Hyperpolarized 129Xe for benchtop NMR: Inline instrumentation for automated yet flexible operation yielding high polarization","authors":"Wolfgang Kilian ,&nbsp;Samira Gulich ,&nbsp;Thomas Riemer ,&nbsp;Lorenz Mitschang","doi":"10.1016/j.jmro.2024.100179","DOIUrl":"10.1016/j.jmro.2024.100179","url":null,"abstract":"<div><div>The use of hyperpolarized media in combination with benchtop NMR spectrometers is currently extensively investigated to enable cost effective but highly sensitive applications. In this work, the instrumentation for the use of hyperpolarized <sup>129</sup>Xe gas on a commercial benchtop-NMR spectrometer in a fully controllable yet automated mode is presented. A continuous-flow <sup>129</sup>Xe polarizer is operated inline with the benchtop spectrometer. While the adjustment of the xenon gas partial pressure in the range of mbar to bar as well as the volume flow through the NMR sample is facilitated by the polarizer’s mass-flow controllers and two back-pressure regulators, respectively, the gas flow towards the NMR sample in situ in the benchtop magnet is time-controlled within the spectrometer’s RF pulse sequence programming. A calibration procedure for the gas flow control as well as thermally polarized xenon gas standards are introduced for quantification of the absolute <sup>129</sup>Xe polarization. In this way, the <sup>129</sup>Xe polarization achieved in the NMR measurement is determined in the 50% to 5% regime for very lean 1<!--> <!-->mbar to high 500<!--> <!-->mbar xenon partial pressure, respectively – in the optimum a more than 250,000-fold increase in comparison to thermal polarization. Such instrumentation may be implemented by combining any of the well-established continuous-flow <sup>129</sup>Xe polarizer with any of the commercial benchtop spectrometers, thus facilitating high-performance hyperpolarized <sup>129</sup>Xe benchtop NMR studies.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"22 ","pages":"Article 100179"},"PeriodicalIF":2.624,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164827","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}
引用次数: 0
Dynamic electron and nuclear spin polarization in solution using porphyrin and tris(2,4,6-trichlorophenyl)-methyl (TTM) radical derivatives 卟啉和三(2,4,6-三氯苯基)-甲基(TTM)自由基衍生物在溶液中的动态电子和核自旋极化
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-12-09 DOI: 10.1016/j.jmro.2024.100181
Reiya Yabuki , Koki Nishimura , Yuta Sawada , Masaaki Fuki , Yasuhiro Kobori , Nobuhiro Yanai
{"title":"Dynamic electron and nuclear spin polarization in solution using porphyrin and tris(2,4,6-trichlorophenyl)-methyl (TTM) radical derivatives","authors":"Reiya Yabuki ,&nbsp;Koki Nishimura ,&nbsp;Yuta Sawada ,&nbsp;Masaaki Fuki ,&nbsp;Yasuhiro Kobori ,&nbsp;Nobuhiro Yanai","doi":"10.1016/j.jmro.2024.100181","DOIUrl":"10.1016/j.jmro.2024.100181","url":null,"abstract":"<div><div>Chemically induced dynamic electron polarization (CIDEP) generates radical electron spins with high polarization at room temperature by quenching the photo-excited state of chromophores, which is useful for microwave-free optical dynamic nuclear polarization (DNP) in solution. While nitroxyl (TEMPO) radicals are typically used for this purpose, we show that a tris(2,4,6-trichlorophenyl)-methyl (TTM) radical derivative shows greater electron spin polarization than TEMPO by CIDEP using porphyrin chromophores. This is attributed to the longer spin-lattice relaxation time of TTM radicals, with a contribution of efficient quenching of chromophore photo-excited state by energy transfer from the triplet state of porphyrins to the doublet state of the TTM radicals. The porphyrin-TTM pair shows a larger nuclear spin polarization under continuous laser excitation than the porphyrin-TEMPO pair because of the larger polarization and longer spin-lattice relaxation time of the TTM radical electron spins. This work demonstrates the first example of in-solution CIDEP and optically-driven DNP using TTM radicals, opening new opportunities in a wide range of biological and medical applications.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"22 ","pages":"Article 100181"},"PeriodicalIF":2.624,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164178","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}
引用次数: 0
Applications of 129Xe and PFG NMR techniques on adsorption and diffusion of molecular sieve materials 129Xe和PFG核磁共振技术在分子筛材料吸附和扩散中的应用
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-12-01 DOI: 10.1016/j.jmro.2024.100180
Shushu Gao , Jiamin Yuan , Fangxiu Ye , Zhiqiang Liu , Anming Zheng , Shutao Xu
{"title":"Applications of 129Xe and PFG NMR techniques on adsorption and diffusion of molecular sieve materials","authors":"Shushu Gao ,&nbsp;Jiamin Yuan ,&nbsp;Fangxiu Ye ,&nbsp;Zhiqiang Liu ,&nbsp;Anming Zheng ,&nbsp;Shutao Xu","doi":"10.1016/j.jmro.2024.100180","DOIUrl":"10.1016/j.jmro.2024.100180","url":null,"abstract":"<div><div>Molecular sieves possess unique properties and have emerged as the predominant catalysts with shape selectivity in the petrochemical industry because of their well-defined pore architectures. However, the existence of a constrained pore surroundings of molecular sieves can limit intracrystalline diffusion, leading to underutilization of the active volume of the molecular sieve or rapid catalysts deactivation during catalytic processes. Moreover, the mechanism of adsorption and diffusion of molecules inside molecular sieves is crucial for the optimization and advancement of catalysts in heterogeneous catalysis. Due to the complexity of the diffusion process in molecular sieve materials, it is very necessary to develop characterization methods that are more sensitive and informative for studying the adsorption and diffusion of guests inside pores. Advancements in characterization techniques and theoretical calculations have led to a more profound comprehension of the adsorption and diffusion properties of molecular sieves at the microscopic scale. This article mainly summarizes the research progress of molecular adsorption and diffusion in molecular sieve materials using advanced <sup>129</sup>Xe NMR, hyperpolarized (HP) <sup>129</sup>Xe NMR, and pulsed-field gradient (PFG) NMR techniques in recent years and focuses on the principles of these techniques and applicability of the relationship of adsorption-diffusion using these techniques within several molecular sieve systems. Moreover, the effects of the topology and pore connectivity of molecular sieves on the adsorption and diffusion of guest molecules as well as the effects of intracrystalline diffusion on catalytic reactions are discussed.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100180"},"PeriodicalIF":2.624,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745759","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}
引用次数: 0
Dynamic nuclear polarization mechanism in isolated NV-centers at high magnetic fields 高磁场下孤立 NV 中心的动态核极化机制
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-11-23 DOI: 10.1016/j.jmro.2024.100178
Shubham Kumar Debadatta, Sheetal Kumar Jain
{"title":"Dynamic nuclear polarization mechanism in isolated NV-centers at high magnetic fields","authors":"Shubham Kumar Debadatta,&nbsp;Sheetal Kumar Jain","doi":"10.1016/j.jmro.2024.100178","DOIUrl":"10.1016/j.jmro.2024.100178","url":null,"abstract":"<div><div>Nitrogen vacancy centers in diamonds are promising spin-based quantum sensors and qubits. These optically addressable paramagnetic point defects have the potential to allow efficient dynamic nuclear polarization (DNP) under ambient conditions due to their large electron spin polarization and long spin coherence time. NV-based DNP studies have shown significant sensitivity enhancement of <sup>13</sup>C nuclear magnetic resonance (NMR). In this work, we present an analytical theory using a density matrix and average Hamiltonian theory for NV-<sup>13</sup>C spin system under varying magnetic fields, internal interaction strengths, and microwave irradiation parameters. We use a reduced basis approach under selective excitation of a single quantum transition in NV-center electron spin levels to derive the expressions for the matching conditions, effective Hamiltonian and polarization transfer frequency. Our results provide insight into the optimal experimental conditions for efficient DNP and the impact of the internal interactions on the DNP performance. The theoretical predictions are verified using numerical simulations.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100178"},"PeriodicalIF":2.624,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722643","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}
引用次数: 0
MQMAS spectra of half-integer quadrupolar nuclei enhanced by indirect DNP 通过间接 DNP 增强的半整数四极核的 MQMAS 光谱
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-11-19 DOI: 10.1016/j.jmro.2024.100177
Hiroki Nagashima , Julien Trébosc , Olivier Lafon , Jean-Paul Amoureux
{"title":"MQMAS spectra of half-integer quadrupolar nuclei enhanced by indirect DNP","authors":"Hiroki Nagashima ,&nbsp;Julien Trébosc ,&nbsp;Olivier Lafon ,&nbsp;Jean-Paul Amoureux","doi":"10.1016/j.jmro.2024.100177","DOIUrl":"10.1016/j.jmro.2024.100177","url":null,"abstract":"<div><div>The observation of half-integer quadrupolar nuclei, which represent 66 % of the NMR-active isotopes, is essential to understand the atomic-level structure of inorganic materials near the surfaces with applications in the field of catalysis, biomaterials and optoelectronics. For that purpose, we have recently introduced an efficient technique, which combines the sensitivity gain provided by indirect DNP (dynamic nuclear polarization) under MAS (magic-angle spinning) and the high resolution obtained by refocusing the second-order quadrupolar interaction (H. Nagashima et al.<em>, J. Phys. Chem. Lett.</em> 15 (2024) 4858). This technique combines (i) a <em>D</em>-RINEPT (dipolar-mediated refocused INEPT) transfer, (ii) an MQMAS (multiple-quantum MAS) filter, and (iii) a QCPMG (quadrupolar Carr-Purcell Meiboom-Gill) detection. We explain the design of several variants of this pulse sequence and notably the selection of the coherence transfer pathways. In particular, the amplitudes of the coherence transfer pathways through the ±3Q coherence orders of the quadrupolar isotope can be equalized using a train of π-pulses selective of the central transition, instead of a z-filter. This equalization method has the advantage to limit the length of the phase cycles and to enhance slightly the signal intensity. Moreover, for spin-3/2 nuclei subject to moderate or large quadrupolar interactions, more efficient excitation and conversion of 3Q coherences are achieved using cosine-modulated long-pulses (cos-lp), instead of fast-amplitude-modulated (FAM) pulses. The performances of the different <em>D</em>-RINEPT-MQMAS-QCPMG variants are compared through the observation of <sup>35</sup>Cl and <sup>27</sup>Al isotopes without DNP in <span>l</span>-histidine hydrochloride and isopropylamine-templated microporous aluminophosphate (ipa-AlPO<sub>4</sub>–14), respectively, as well as the acquisition of DNP-enhanced high-resolution spectra of <sup>11</sup>B and <sup>17</sup>O nuclei near the surface of partially oxidized boron nitride supported on dendritic and fibrous nanosilica and γ-alumina enriched in <sup>17</sup>O isotope using a slurrying approach. The spectra recorded for γ-alumina show that the slurrying method produces less disorder than grinding assisted by <sup>17</sup>O-enriched water.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100177"},"PeriodicalIF":2.624,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722642","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}
引用次数: 0
A miniaturized dual-mode continuous-wave and pulsed pumping ODNP platform 微型化双模连续波和脉冲泵浦 ODNP 平台
IF 2.624
Journal of Magnetic Resonance Open Pub Date : 2024-11-19 DOI: 10.1016/j.jmro.2024.100174
Qing Yang , Hadi Lotfi , Michal Kern , Frederik Dreyer , Mazin Jouda , Jan. G. Korvink , Bernhard Blümich , Jens Anders
{"title":"A miniaturized dual-mode continuous-wave and pulsed pumping ODNP platform","authors":"Qing Yang ,&nbsp;Hadi Lotfi ,&nbsp;Michal Kern ,&nbsp;Frederik Dreyer ,&nbsp;Mazin Jouda ,&nbsp;Jan. G. Korvink ,&nbsp;Bernhard Blümich ,&nbsp;Jens Anders","doi":"10.1016/j.jmro.2024.100174","DOIUrl":"10.1016/j.jmro.2024.100174","url":null,"abstract":"<div><div>In this paper, we present the design and experimental validation of a miniaturized Overhauser dynamic nuclear polarization (ODNP) platform for both continuous-wave (CW) and pulsed DNP enhancement experiments at a <span><math><msub><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> field strength of 0.25<!--> <!-->T. The platform is centered around chip-integrated nuclear magnetic resonance (NMR) and microwave (MW) electronics and further incorporates a custom-designed laser-engraved ODNP probe, providing phase-coherent radio frequency (RF) excitation, low-noise amplification and acquisition of NMR signals, MW frequency synthesis, MW signal modulation, and MW power amplification. An experimental validation using TEMPOL solutions with different concentrations demonstrates the functionality and good performance of the presented ODNP platform. A maximum enhancement of <span><math><mrow><mo>−</mo><mn>92</mn></mrow></math></span> with CW pumping was achieved using a 500<!--> <!-->nL 10<!--> <!-->mM non-degassed TEMPOL solution in water, representing the largest enhancement achieved to date in a chip-based ODNP platform. We also include a preliminary comparison between CW pumping and pulsed pumping using TEMPOL solutions with different electron relaxation times (apparent <span><math><msub><mrow><mi>T</mi></mrow><mrow><msup><mrow><mn>1</mn><mi>e</mi></mrow><mrow><mo>∗</mo></mrow></msup></mrow></msub></math></span> and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>2e</mi></mrow></msub></math></span>). Our study indicates that, for a power-limited miniaturized ODNP platform, pulsed pumping can surpass CW pumping in power efficiency for a given average power when the solution possesses a sufficiently long electron spin-lattice relaxation time.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100174"},"PeriodicalIF":2.624,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704454","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}
引用次数: 0
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