Journal of Magnetic Resonance Open最新文献

{"title":"Probing nanoparticle proximity effects on selective butadiene hydrogenation over Pd-Au/TiO2 with parahydrogen-induced polarization NMR","authors":"Bintian Lu ,&nbsp;Weiyu Wang ,&nbsp;Shuangqin Zeng ,&nbsp;Xiuzhi Gao ,&nbsp;Jun Xu ,&nbsp;Feng Deng","doi":"10.1016/j.jmro.2025.100192","DOIUrl":"10.1016/j.jmro.2025.100192","url":null,"abstract":"<div><div>Selective butadiene hydrogenation to butene is a crucial process in the petrochemical industry, however, a comprehensive understanding of the underlying structure-activity relationships remains elusive. This study explores the influence of supported metal nanoparticle proximity on butadiene hydrogenation using parahydrogen-induced polarization NMR spectroscopy. A sol-immobilization method was employed to systematically control the spacing between PdAu nanoparticles on Pd-Au/TiO₂ catalysts, while preserving their overall physicochemical properties. Experimental results demonstrate that denser PdAu nanoparticle arrangements lead to enhanced catalytic activity. This improved activity is coupled with accelerated isomerization of the semi-hydrogenated butene and over-hydrogenation to butane, facilitated by enhanced butene adsorption and subsequent conversion. Furthermore, increasing the hydrogen content significantly boosts butadiene conversion and butane formation, while having a less impact on butene isomerization. The addition of an inert support material, altering the spatial distribution of catalyst particles, positively affects both catalytic activity and butene selectivity. These findings highlight the critical role of nanoparticle proximity in controlling reaction pathways in butadiene hydrogenation.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100192"},"PeriodicalIF":2.624,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577291","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":"Evaluating metrics of spectral quality in nonuniform sampling","authors":"D. Levi Love,&nbsp;Michael R. Gryk,&nbsp;Adam D. Schuyler","doi":"10.1016/j.jmro.2025.100187","DOIUrl":"10.1016/j.jmro.2025.100187","url":null,"abstract":"<div><div>In pursuit of an adaptive approach to nonuniform sampling (<strong>NUS</strong>), two critical determinants arise: (1) the ability to determine an endpoint by way of quantitatively assessing spectral quality and (2) the ability to systematically determine what additional FIDs to collect if the aforementioned stop criteria is not met. As previously established, <em>in situ</em> receiver operator characteristic (<strong>IROC</strong>, (Zambrello et al., 2017)) assesses the recovery of injected synthetic ground truth signals to define spectral quality. The Nonuniform Sampling Contest (<strong>NUScon</strong>, (Pustovalova et al., 2021)), defines a workflow for processing NUS experiments and quantitatively evaluating spectral quality. We augmented that workflow by including an IROC module, which we believe to be an effective component of defining stop criteria for adaptive FID collection. As for the decision of what additional FIDs, this study builds off the work of prior studies on the influence the seed used to generate a nonuniform sample schedule has on the quality of a NUS reconstruction (Hyberts et al., 2011), i.e., whether a sampling method yields “high-variance” or “low-variance” schedules (Zambrello et al., 2020). Namely, existing work has been focused on reducing seed-dependence (Eddy et al., 2012; Mobli, 2015; Worley, 2016) or “optimizing” the seed (Hyberts and Wagner, 2022) by evaluating sample schedules using a computationally inexpensive metric based on the characterization of the point-spread function, like sidelobe-to-peak ratio (Lustig et al., 2007) and peak-to-sidelobe ratio (<strong>PSR</strong>, (Eddy et al., 2012; Mobli, 2015; Worley, 2016; Craft et al., 2018)). This study assesses the ability of PSR, an <em>a priori</em> metric that is based solely on the nonuniform sample schedule, to predict spectral quality as assessed by IROC. This work uses IROC to show that seed optimization via PSR does not result in better quality spectra. In addition, the trends observed in the spectral quality reported by IROC informs our future designs for adaptive FID selection.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100187"},"PeriodicalIF":2.624,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464323","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":"Robotic arms for hyperpolarization-enhanced NMR","authors":"Kirill Sheberstov ,&nbsp;Erik Van Dyke ,&nbsp;Jingyan Xu ,&nbsp;Raphael Kircher ,&nbsp;Liubov Chuchkova ,&nbsp;Yinan Hu ,&nbsp;Sulaiman Alvi ,&nbsp;Dmitry Budker ,&nbsp;Danila A. Barskiy","doi":"10.1016/j.jmro.2025.100194","DOIUrl":"10.1016/j.jmro.2025.100194","url":null,"abstract":"<div><div>Optimization of nuclear spin hyperpolarization experiments often require varying one system parameter at a time (or several parameters in a nontrivial manner) as well as multiple repetitions of signal measurements. Use of automated robotic systems can significantly streamline this optimization process, accelerating data acquisition and improving reproducibility in the long term. In this work we show an exemplary system built on open-source components and demonstrate several benchtop and ultralow-field NMR experiments employing photo-CIDNP and SABRE-derived hyperpolarization. This work illustrates that open-source platforms employing benchtop NMR and robotic systems built in a modular manner with remote operation allow the implementation of various unconventional experiments in a reproducible manner.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100194"},"PeriodicalIF":2.624,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577292","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":"Avoiding broadband radiation damping effects in NOESY spectra","authors":"Kelsey Anne Marr,&nbsp;Alexej Jerschow","doi":"10.1016/j.jmro.2025.100203","DOIUrl":"10.1016/j.jmro.2025.100203","url":null,"abstract":"<div><div>Radiation damping is a well-known phenomenon in the context of NMR spectroscopy. Several strategies exist for minimizing the effects of radiation damping, which have mostly been focused on limiting the effects of one resonance (frequently the water resonance). When samples with many resonances are examined at high concentration, such approaches often cannot be used. One category of systems where the broadband nature of radiation damping leads to complications are deep eutectic solvents (DESs). DESs are considered innovative solvent systems that have several advantages such as tunability and environmental friendliness, with important applications ranging from catalysis to drug delivery. It is of interest to examine the intermolecular effects via NMR spectroscopy in these systems. Here we show that broadband radiation effects are very strong in these systems and identify simple strategies specifically for 2D NOESY NMR spectroscopy to regain the ability to quantify intermolecular interactions in these systems.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100203"},"PeriodicalIF":2.624,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to average Hamiltonian theory. II. Advanced examples","authors":"Andreas Brinkmann","doi":"10.1016/j.jmro.2025.100191","DOIUrl":"10.1016/j.jmro.2025.100191","url":null,"abstract":"<div><div>Where the first part of our tutorial <em>Introduction to average Hamiltonian theory</em> (Brinkmann, 2016) introduced in detail the basic concepts and demonstrated the application to two composite radio-frequency (rf) pulses in nuclear magnetic resonance (NMR) spectroscopy, this second part will present in a comprehensive but educational manner two, more advanced examples for the application of average Hamiltonian theory in solid-state NMR spectroscopy, both to analyse and design rf pulse sequences: (i) The Rotational-Echo Double Resonance (REDOR) sequence, which recouples the heteronuclear dipolar coupling during sample rotation around an axis at the magic-angle of <span><math><mrow><mn>54</mn><mo>.</mo><mn>7</mn><msup><mrow><mn>4</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> with respect to the external static magnetic field. We will gradually increase the complexity of applying average Hamiltonian theory by first considering ideal, infinitesimally short rf pulses. Next, we will examine finite pulses with an rf phase of zero, and finally, we will explore finite pulses with arbitrary rf phases. In the latter case, if a first order average Hamiltonian proportional to heteronuclear longitudinal two-spin order (<span><math><mrow><mn>2</mn><msub><mrow><mi>I</mi></mrow><mrow><mi>z</mi></mrow></msub><msub><mrow><mi>S</mi></mrow><mrow><mi>z</mi></mrow></msub></mrow></math></span>) is desired, solutions for the choice of rf phases include the XY and MLEV type schemes. (ii) The Lee–Goldburg homonuclear dipolar decoupling sequence under static samples conditions and its improved successors, Flip-Flop Lee–Goldburg (FFLG) and Frequency-Switched Lee–Goldburg (FSLG).</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100191"},"PeriodicalIF":2.624,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474023","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":"Paramagnetic relaxation: Direct and Raman relaxation of spin S=12","authors":"W.Th. Wenckebach","doi":"10.1016/j.jmro.2025.100193","DOIUrl":"10.1016/j.jmro.2025.100193","url":null,"abstract":"<div><div>Paramagnetic relaxation in solids is a vast subject, about as vast as the range of manifestations of electron spin in matter. It is a complex subject as well: it is the interface between paramagnetic centres – be it transition metal ions, radicals or defects – and quantized vibrations: phonons. So it requires an understanding of both these phonons and those paramagnetic centres. Moreover, contrary to the case of integer spin, for half-integer spin the coupling between electron spins and phonons is indirect. Two interactions are needed, the spin–orbit interaction between the spin and the orbits of the paramagnetic centre and the orbit–phonon interaction between the latter and the phonons.</div><div>The present article is an effort to navigate the theory of this extensive subject for spin <span><math><mrow><mi>S</mi><mo>=</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac></mrow></math></span> and aims to derive the main properties of the two most important mechanisms: direct and red Raman relaxation. It tries to do so from first principles, that is, it includes a generalized, but fundamental description of the vibrational states, the orbital and spin states on the one hand, and the orbit–phonon and spin–orbit interaction on the other. Based on these descriptions it derives the transition matrix elements responsible for paramagnetic relaxation, following the original approach of Van Vleck for paramagnetic centres with spin <span><math><mrow><mi>S</mi><mo>=</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac></mrow></math></span>, a relatively weak spin–orbit interaction and embedded in an insulating, diamagnetic solid. Subsequently phonon statistics are included to derive the paramagnetic relaxation rates. No effort is done to review the vast body of experimental work on the subject.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100193"},"PeriodicalIF":2.624,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing cation dynamics and phase transition in hybrid organic-inorganic perovskites by 13C solid-state NMR spectroscopy at very high resolution","authors":"Yue Dou ,&nbsp;Qing Wang ,&nbsp;Hengxing Ji ,&nbsp;Haiming Liu","doi":"10.1016/j.jmro.2025.100197","DOIUrl":"10.1016/j.jmro.2025.100197","url":null,"abstract":"<div><div>The spatial dynamics of cations have a significant impact on the photodynamic behavior of excited states in high-performance hybrid organic-inorganic perovskites. Multinuclear (¹H, ²H, and ¹⁴N) solid-state NMR (SSNMR) spectroscopy has traditionally been utilized to study the motion of methylammonium (MA) cations in methylammonium lead (II) halides MAPbX₃ (X = I, Br, Cl). NMR methods based on spin-lattice relaxation or quadrupolar line shape analysis over a limited temperature range demonstrate rapid MA reorientation, but the cation dynamics in a wider temperature range covering phase transition of all major crystallographic phases is lacking. Due to its low sensitivity, ¹³C NMR is rarely used to assess MA dynamics in these perovskites. Herein, we adopte variable-temperature (VT) ¹³C MAS NMR at very high resolution and dipolar-coupled transverse relaxation analysis as a new tool for dynamical characterization without isotopic enrichment, and systematically investigated MA dynamics in MAPbX₃ across phase transitions. This new approach enables retrieval of activation energy of MA reorientation and assessment of motion regimes. We propose a generalized “Camel model” that describes the common trend of cation dynamics for MAPbX₃, suggesting possible complicated reorientation modes. Furthermore, we discover the evolution of multiple MA sites in orthorhombic MAPbCl₃, consistent with X-ray crystallography, demonstrating its unique advantage in resolving and characterizing multi-cation dynamics. The VT ¹³C SSNMR effectively probes organic ion motions and phase transitions in hybrid perovskites, helpful for further elucidating the structure-property relationship in photovoltaic conversion mechanisms.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100197"},"PeriodicalIF":2.624,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738290","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":"Determination of the surface relaxivity of soft sediment using particle size and shape","authors":"Nick J. Hol ,&nbsp;Ismail Myouri ,&nbsp;Claire Chassagne ,&nbsp;Leo Pel","doi":"10.1016/j.jmro.2025.100198","DOIUrl":"10.1016/j.jmro.2025.100198","url":null,"abstract":"<div><div>This study presents a method to determine surface relaxivity in soft sediments by combining one-dimensional Nuclear Magnetic Resonance (NMR) imaging with particle size and shape estimates. In order to determine the surface relaxivity up to now often methods like Mercury Intrusion Porosimetry or Brunauer–Emmett–Teller (BET) are used which where drying steps are involved which can alter material properties during analysis, particularly in highly deformable materials, making these techniques unreliable for soft soils. By combining NMR relaxometry and estimates of particle sizes and shapes of a soft soil, this new approach provides accurate, non-invasive surface relaxivity measurements. This method is demonstrated on kaolinite, glass beads, and natural soils, showing that this method supports detailed assessment of pore size distributions in soft sediments, benefiting geotechnical and environmental research where soil stability is critical.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"23 ","pages":"Article 100198"},"PeriodicalIF":2.624,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chiral recognition of some D and L-amino acids by microcrystalline cellulose assisted diffusion-ordered NMR spectroscopy","authors":"Bowen Han ,&nbsp;Jing He ,&nbsp;Shaohua Huang","doi":"10.1016/j.jmro.2025.100189","DOIUrl":"10.1016/j.jmro.2025.100189","url":null,"abstract":"<div><div>Chiral amino acids play an indispensable role in living organisms. Diffusion-ordered NMR spectroscopy is an effective NMR tool and a noninvasive analytical method for the analyses of mixture without the need for physical separation of the analytes. However, conventional diffusion-ordered NMR spectroscopy method usually fails to resolve the mixtures of chiral amino acids because of their same molecular masses, sizes, and shapes. Microcrystalline cellulose has been gradually gained more and more interest owing to its wide compatibility, surface area, excellent separation efficiency, non-toxicity, cost-effective, and mechanical stability in many fields. Herein we provide a fast, simple, specific and sensitive method to resolve some D and L-amino acids mixtures by using microcrystalline cellulose as a matrix. This work recognized some D and L- proteinogenic amino acid enantiomers with diffusion-ordered NMR for the first time.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"22 ","pages":"Article 100189"},"PeriodicalIF":2.624,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164179","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 hybrid setup for rodent hyperpolarized metabolic imaging using a clinical magnetic resonance scanner","authors":"Ditte Bentsen Christensen ,&nbsp;Ingeborg Sæten Skre ,&nbsp;Jan Henrik Ardenkjær-Larsen ,&nbsp;Mor Mishkovsky ,&nbsp;Mathilde H Lerche","doi":"10.1016/j.jmro.2025.100190","DOIUrl":"10.1016/j.jmro.2025.100190","url":null,"abstract":"<div><div>Metabolic magnetic resonance spectroscopic imaging using hyperpolarized contrast agents offers a non-invasive approach to monitoring real-time in vivo energy metabolism. The technique involves hyperpolarizing a contrast agent in a polarizer, administering it to a living system, and then imaging its distribution and metabolites using a magnetic resonance scanner. Over the past two decades, the method has transitioned from in vitro studies to clinical research, with an increasing focus on clinical applications.</div><div>Here, we present a hybrid system that adapts a clinical magnetic resonance scanner for pre-clinical rodent experiments. The hybrid system includes (1) a customizable, 3D-printable animal cradle setup and (2) optimized imaging strategies, including coil configurations, metabolic contrast agent administration, and proton imaging acquisition. The system enables ¹³C dynamic imaging, which we illustrate with detection of hyperpolarized [1–¹³C]pyruvate and its metabolites in the mouse brain. We detail the experimental procedure, provide practical guidance, and showcase the capabilities of the system with example data from mouse brain imaging.</div><div>This hybrid setup bridges the gap between clinical and pre-clinical research, enabling iterative testing of equipment, imaging sequences, and hypotheses across phantoms, in vivo rodent models and clinical settings. By facilitating a smoother translation, both forward and reverse, between pre-clinical and clinical applications, this approach enhances the potential for advancing metabolic imaging research.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"22 ","pages":"Article 100190"},"PeriodicalIF":2.624,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143353597","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}