Applied Magnetic Resonance最新文献

{"title":"NMR Spectroscopic and Theoretical Analysis of Boron Incorporation into the AlPO-41 Framework Facilitated by Silicon","authors":"Ilya V. Yakovlev,&nbsp;Aleksandr V. Toktarev,&nbsp;Aleksandr A. Shubin,&nbsp;Evgeniy S. Papulovskiy,&nbsp;Olga B. Lapina","doi":"10.1007/s00723-025-01770-3","DOIUrl":"10.1007/s00723-025-01770-3","url":null,"abstract":"<div><p>The introduction of boron into the aluminophosphate AlPO-41 framework (AFO structure), enhanced by the presence of silicon, was investigated using solid-state NMR spectroscopy and DFT calculations. While boron incorporation into the pure AlPO-41 was negligible, simultaneous co-substitution with silicon facilitated the stabilization of tetrahedral boron within the framework, as evidenced by ¹¹B solid-state NMR. ²⁹Si NMR revealed a more uniform silicon distribution in BSAPO-41 compared to SAPO-41, with isolated Si(4Al) sites and silicon patches identified. The theoretical modeling suggested preferential substitution sites for Si and B. These findings highlight the synergistic role of silicon in enabling boron incorporation, offering a pathway to fine-tune the acidity and catalytic properties of aluminophosphate molecular sieves. Additionally, the theoretical modeling allowed to establish the mechanism of hydration of AlPO-41.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 8","pages":"1031 - 1043"},"PeriodicalIF":1.1,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Kinetic EPR Method with Pulse Reagent Injection as an Efficient Approach for Direct Determination of Antiradical Capacities of Polyphenolic Compounds","authors":"Gaspar Kocharyan,&nbsp;Adrine D. Sahakyan,&nbsp;Zaruhi H. Manukyan,&nbsp;Samvel Kh. Stepanyan,&nbsp;Daria A. Pomogailo,&nbsp;Makich V. Musaelyan","doi":"10.1007/s00723-025-01769-w","DOIUrl":"10.1007/s00723-025-01769-w","url":null,"abstract":"<div><p>Flavonoids — quercetin, rutin, and morin — were kinetically studied as antioxidants in the scavenging of <i>tert</i>-butyl peroxyl radical (<span>(tert - {text{ butylOO}}^{ bullet })</span>) and compared with the reference antioxidant Trolox. For the first time, a direct kinetic electron paramagnetic resonance (EPR) method with pulse injection of reagents was used to determine the anti <span>(tert - {text{ butylOO}}^{ bullet })</span> capacity of the selected flavonoids. The antiradical capacities of the studied compounds were measured at − 32 °C and compared with the results obtained using the widely used oxygen radical absorbance capacity (ORAC) method. It was established that the kinetic EPR method with pulse reagent injection allows for effective and highly accurate determination of the anti-peroxyl radical capacities of polyphenolic compounds with multiple active centers, particularly flavonoids. The obtained data provide key insights for understanding structure–activity relationships (SAR) and the antiradical potential of flavonoids as peroxyl radical scavengers at the molecular level.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 8","pages":"985 - 993"},"PeriodicalIF":1.1,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lindblad Dephasing Relaxation and Quantum Entanglement in Two-Spin Systems in Multiple-Quantum NMR Experiments","authors":"E. B. Fel’dman,&nbsp;E. I. Kuznetsova,&nbsp;E. I. Shipulya,&nbsp;S. G. Vasil’ev,&nbsp;A. I. Zenchuk","doi":"10.1007/s00723-025-01763-2","DOIUrl":"10.1007/s00723-025-01763-2","url":null,"abstract":"<div><p>Dephasing relaxation and quantum entanglement are studied in a two-spin-1/2 system with the dipole–dipole interaction on a basis of the Lindblad equation in multiple-quantum NMR experiments. A multiple-quantum (MQ) NMR dynamics is investigated. It is shown that MQ NMR spectrum consists of only MQ NMR coherences of zeroth- and plus/minus-second orders. Intensities of MQ NMR coherences are calculated. Quantum correlations (entanglement) are also considered. The relationship between entanglement and the MQ NMR coherence of the second order is also investigated.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 8","pages":"1053 - 1062"},"PeriodicalIF":1.1,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Transformations in the Bulk Ga–In Melt: NMR Studies","authors":"A. A. Vasilev,&nbsp;D. Yu. Nefedov,&nbsp;E. V. Charnaya","doi":"10.1007/s00723-025-01765-0","DOIUrl":"10.1007/s00723-025-01765-0","url":null,"abstract":"<div><p>Recently, interest to the Ga–In binary alloy increased remarkably because of its new applications in biology, medicine, flexible robotics, and wearable electronics. We present detailed studies of the evolution of the ⁷¹ Ga and ¹¹⁵In NMR spectra within the temperature range between the complete melted and complete frozen states of the bulk Ga–In alloy aimed to find evidences for the liquid–liquid transition. The Ga–In alloy composition was close to the eutectic point for α-Ga. While the structural transformations were revealed in the supercooled pure gallium and some gallium alloys under nanoconfinement, they were not found in their bulk counterparts, in spite of being theoretically predicted for pure gallium. Changes in the lineshapes and line splitting were found for both gallium and indium isotopes between 277 and 268 K upon cooling and between 250 and 260 K upon warming. The resonance lines within these temperature ranges were deconvolved into two components. Measurements during additional thermal cycles and the analysis of the Knight shifts and intensities of the components proved the occurrence of the liquid–liquid-phase transitions.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 8","pages":"995 - 1006"},"PeriodicalIF":1.1,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quadrupole Spin–Lattice Relaxation of 69Ga and 71Ga in a GaAs Semi-insulator Crystal","authors":"A. M. Rochev,&nbsp;V. M. Mikushev,&nbsp;E. V. Charnaya","doi":"10.1007/s00723-025-01764-1","DOIUrl":"10.1007/s00723-025-01764-1","url":null,"abstract":"<div><p>NMR studies of spin–lattice relaxation were carried out for two gallium isotopes, ⁶⁹Ga and ⁷¹Ga, for an undoped semi-insulator GaAs crystal under the additional continuous magnetic saturation of the nuclear spin systems at the Larmor frequencies. The magnetization recovery after inversion was observed within the temperature range from 80 to 300 K using a Bruker Avance 400 pulse spectrometer. Two main contributions to relaxation due to the hyperfine coupling with the electron centers accompanied by spin diffusion and due to the spin–phonon interaction in the regular crystal lattice were separated by suppressing the first one. Both contributions to relaxation were found to be of the quadrupole nature and followed the temperature dependence predicted for quadrupole relaxation owing to the modulation by thermal phonons of the electric field gradients at nuclei. The results obtained are consistent with the suggestion that the quadrupole hyperfine coupling dominates for nuclei in the neighborhood of the electron centers and the rapid spin diffusion approximation is satisfied.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 8","pages":"1045 - 1052"},"PeriodicalIF":1.1,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-Field NMR for Controlling “Vegan” Food Labelling: Retrospective Analysis of Dairy Products from Germany","authors":"Klaudia Adels,&nbsp;Yulia Monakhova","doi":"10.1007/s00723-025-01762-3","DOIUrl":"10.1007/s00723-025-01762-3","url":null,"abstract":"<div><p>The food industry is creating a diverse range of plant-based alternatives to dairy products, due to the increasing demand from consumers for more sustainable, healthy, and ethical products. Since such products are often more expensive than conventional cow’s milk products, quick, accurate and low-cost instrumental method is necessary to prove the labelling claim. The objective of the research was to examine the use of low-field ¹H-NMR spectroscopy at 80 MHz to differentiate between vegan and non-vegan dairy products as well as among different botanical origins of vegan products. More than 100 samples of vegan and non-vegan products (yoghurt, milk, (cooking) cream, cottage cheese and condensed milk), which are representative of the German market, were investigated. Carbohydrate profile, in particular lactose, glucose, sucrose and galactose, extracted in aqueous phase, can be used to differentiate lactose-free, lactose-containing and plant surrogates. Supplementary information is hidden in fatty acids profile of the investigated products. Exploratory analysis based on principal component analysis (PCA) confirmed and supplemented findings of visual spectra interpretation. Low-field NMR can be a quicker and cheaper alternative to conventional techniques for food label control from both animal and botanical origin.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 7","pages":"871 - 885"},"PeriodicalIF":1.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-025-01762-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145168558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wearable Resonator for In Vivo Electron Paramagnetic Resonance Tooth Dosimetry","authors":"Chang Uk Koo,&nbsp;Jeonghun Oh,&nbsp;Kwon Choi,&nbsp;Sung-Joon Ye","doi":"10.1007/s00723-025-01761-4","DOIUrl":"10.1007/s00723-025-01761-4","url":null,"abstract":"<div><p>Tooth radiation dosimetry using an in vivo electron paramagnetic resonance (EPR) spectrometer serves as a triage method for victims in large-scale radiation emergencies, such as the Fukushima and Chernobyl accidents. However, the victim’s breathing and movement during in vivo measurements causes signal loss and uncertainty in the radiation-induced signal (RIS). This study aims to address these issues by developing a wearable resonator for a tooth. Using ANSYS High Frequency Structure Simulation (HFSS), the dimensions and configuration of an attachable surface coil were optimized by calculating the magnetic field distribution in the enamel volume of a 3D incisor model. The magnetic energy concentration on the tooth enamel was maximized by the attachable surface coil, which had a 5 mm inner diameter and a 0.7 mm trace width at a given microwave power. To assess the dosimetric performance, a 50-Gy irradiated tooth was measured by an optimized wearable resonator. The tooth measurement was conducted by employing homebuilt 1.15 GHz continuous-wave EPR spectroscopy. The configured wearable resonator produced a constant RIS amplitude with a ± 2.0% variation from an exposed tooth sample, even with a 2 mm movement along the central axis. In addition, secure fixation of the wearable resonator resulted in significant stability, showing a relatively low uncertainty of 1.2% in the RIS amplitude. The wearable resonator also achieved an ~ 8.4% increase in RIS amplitude by concentrating more magnetic energy on the tooth sample compared to a conventional rigid resonator. This enhancement improved the accuracy and sensitivity of in vivo tooth dosimetry. In conjunction with an automatic control circuit (ACC), the wearable resonator acquired undistorted in vivo EPR spectra; thereby, significantly reducing the need for manual intervention to reset the device due to the in vivo motion. This combination of the wearable resonator and ACC effectively established a motion compensation system for in vivo EPR tooth dosimetry.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 7","pages":"887 - 902"},"PeriodicalIF":1.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-025-01761-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transforming Medical Imaging with IVIM MR Imaging: A Comprehensive Review of Advances and Challenges in Perfusion and Diffusion Analysis","authors":"Jini Raju,&nbsp;A. Shyna,&nbsp;Ansamma John,&nbsp;Manu J. Pillai","doi":"10.1007/s00723-025-01758-z","DOIUrl":"10.1007/s00723-025-01758-z","url":null,"abstract":"<div><p>Medical imaging plays a pivotal role in modern healthcare, with Magnetic Resonance Imaging (MRI) standing out for its exceptional resolution and non-ionizing nature. Diffusion-Weighted Imaging (DWI) has further enhanced the diagnostic capability of MRI by visualizing tissue microstructure, making it invaluable for early disease detection, but it cannot assess perfusion. IntraVoxel Incoherent Motion (IVIM) MRI addresses this gap by simultaneously quantifying both diffusion and perfusion, offering deeper insights into tissue characteristics. However, its clinical adoption remains limited due to challenges such as the lack of standardized algorithms, noise-related image degradation, and variability in parameter estimation. This review explores the evolution of IVIM MRI, its physiological models for parameter estimation, the impact of noise and denoising techniques on image quality, and different fitting approaches to improve accuracy and reliability. The exploration of these areas in this work aims to enhance the reliability of IVIM and facilitate its integration into clinical practice, ultimately improving diagnostic accuracy and patient outcomes across diverse medical conditions.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 7","pages":"803 - 843"},"PeriodicalIF":1.1,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145170017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fractional Anisotropy as a Potential Marker of Blood–Brain Barrier Disruption in a Rat Model of Ischemia–Reperfusion Injury","authors":"Duen-Pang Kuo,&nbsp;Hua-Shan Liu,&nbsp;Yung-Chieh Chen,&nbsp;Chen-Yin Ou,&nbsp;Cheng-Yu Chen","doi":"10.1007/s00723-025-01759-y","DOIUrl":"10.1007/s00723-025-01759-y","url":null,"abstract":"<div><p>While gadolinium-enhanced magnetic resonance imaging (MRI) enables assessment of blood–brain barrier (BBB) integrity post-stroke, it presents inherent risks and limitations. We evaluated diffusion tensor imaging (DTI) as a contrast-free method for monitoring BBB integrity during ischemia–reperfusion (I/R) in a rat stroke model. Seventeen Sprague–Dawley rats underwent one-hour transient middle cerebral artery occlusion (MCAO). Serial MRI sequences, including DTI, perfusion-weighted imaging, and T1 mapping, were performed to monitor BBB permeability (BBBP) dynamics in regions initially identified as ischemic penumbra (IP) and ischemic core (IC) during MCAO. The fractional anisotropy (FA) ratio (rFA) was compared with BBBP changes throughout the observation period. In the IC, rFA values exhibited a 13% increase during ischemia, followed by a 10% decrease post-recanalization, and a 36% decline at 120 h post-reperfusion. Although BBBP in the IC decreased during ischemia and normalized post-reperfusion, persistent leakage was observed. The IP maintained stable rFA and BBB integrity throughout I/R. Strong negative correlations between rFA and BBBP were found in ischemic regions (IC: r = − 0.90, p &lt; 0.001; IP: r = − 0.78, p = 0.007), with FA reductions at 24 h post-reperfusion predicting BBB disruption at 120 h. These findings suggest that DTI metrics correlate significantly with BBB integrity during I/R, indicating potential utility as a contrast-free monitoring tool for early detection of BBB impairment following stroke.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 7","pages":"845 - 858"},"PeriodicalIF":1.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Investigation of Dosimetric Potentials of Surgical Face Masks Using Electron Spin Resonance Spectroscopy","authors":"Hülya Karaaslan,&nbsp;Selin Erzin","doi":"10.1007/s00723-025-01760-5","DOIUrl":"10.1007/s00723-025-01760-5","url":null,"abstract":"<div><p>In this study, the Electron Spin Resonance (ESR) dosimetric potential of surgical face masks was investigated within the intermediate gamma dose range of 0.05–10 kGy. White, blue, and green mask samples were used for this analysis. FTIR and XRD analyses confirmed that all masks were made of polypropylene. No ESR signals were detected in the unirradiated masks. However, in gamma-irradiated samples, resonance signal components at <span>({g}_{parallel }= 2.031 pm 0.002)</span> and <span>({g}_{perp }= 2.007 pm 0.002)</span>, associated with peroxy radicals (RO2·), were observed, with the intensity of the <span>({g}_{perp }= 2.007 pm 0.002)</span> signal increasing exponentially within the investigated dose range. Despite the decrease in radiation-induced signal intensities at room temperature, surgical masks can be considered as emergency dosimeters when other materials suitable for dose estimation are unavailable.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 7","pages":"859 - 870"},"PeriodicalIF":1.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}