Kirill A. Gomonov, Vasilii V. Pelipko, Igor A. Litvinov, Ruslan I. Baichurin, Sergey V. Makarenko
{"title":"Nuclear Overhauser Effect in Determining the Configuration of 2-Nitrofuran-3-Carboxylates Hydrazones","authors":"Kirill A. Gomonov, Vasilii V. Pelipko, Igor A. Litvinov, Ruslan I. Baichurin, Sergey V. Makarenko","doi":"10.1007/s00723-024-01677-5","DOIUrl":"10.1007/s00723-024-01677-5","url":null,"abstract":"<div><p>The structure of 4-acetyl-2-nitrofuran-3-carboxylates hydrazones obtained from the interaction of 4-acetyl-5-methyl-2-nitrofuran-3-carboxylates with substituted hydrazines was studied using 1D and 2D <sup>1</sup>H, <sup>13</sup>C NMR spectroscopy. According to <sup>1</sup>H–<sup>1</sup>H NOESY data, it was shown that the hydrazones under consideration exist in the <i>E</i>-configuration, confirmed by X-ray diffraction analysis.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 8","pages":"839 - 846"},"PeriodicalIF":1.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141609082","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}
Quan Lam, Casey Van Stappen, Yi Lu, Sergei A. Dikanov
{"title":"1H HYSCORE Studies of Second Sphere Variants of the Type 1 Copper Site in Azurin: Influence of Mutations on the Hyperfine Couplings of Cys112 CβH2 Protons","authors":"Quan Lam, Casey Van Stappen, Yi Lu, Sergei A. Dikanov","doi":"10.1007/s00723-024-01665-9","DOIUrl":"10.1007/s00723-024-01665-9","url":null,"abstract":"<div><p>In this work, we examined the influence of F114P, F114N, and N47S mutations on the electronic structure of the T1 copper center in azurin (Az) by studying the hyperfine couplings of C<sub>β</sub>H<sub>2</sub> protons of Cys112 using the two-dimensional (2D) pulsed EPR technique HYSCORE (hyperfine sublevel correlation). Our results show that isotropic hyperfine couplings for the two Cys112 C<sub>β</sub> protons in WTAz, F114NAz, and N47SAz vary within 21 ± 2 MHz, with differences of only several tenths of MHz between the two protons in a given protein despite major variations previously observed in S<sub>C112</sub> electron density. Furthermore, significantly smaller couplings of 0.7 MHz and 7.4 MHz are observed for the F114PAz mutation—which eliminates a backbone amide H-bonding interaction with S<sub>C112</sub>—despite previous observations of a significant <i>increase</i> in S character in the SOMO, demonstrating a more complex relationship between C<sub>β</sub>–<sup>1</sup>H hyperfine and the unpaired spin density of S<sub>C112</sub> than previously proposed. In addition, the 2D HYSCORE spectra show resolvable differences in the anisotropic couplings between the two protons in all samples, indicating inconsistencies between previously reported ENDOR and computational data for the WTAz protein. Other findings visible in 2D spectra is the distortion of the cross-ridges from Cys112 C<sub>β</sub>H<sub>2</sub> protons with the large isotropic couplings resulted from <i>a</i><sub><i>iso</i></sub> strain produced by the fluctuations of the C<sub>β</sub>‒H<sub>2</sub> group orientation within <i>θ</i> ~ ± 2° degrees around the most populated conformation.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 9","pages":"1159 - 1174"},"PeriodicalIF":1.1,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571777","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}
Konstantin V. Tyutyukin, Alexandr V. Ievlev, Vladimir V. Matveev, Luis M. Varela, Oscar Cabeza
{"title":"Molecular Mobility Study of 1-Butyl-1-Methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquid by NMR Diffusometry","authors":"Konstantin V. Tyutyukin, Alexandr V. Ievlev, Vladimir V. Matveev, Luis M. Varela, Oscar Cabeza","doi":"10.1007/s00723-024-01678-4","DOIUrl":"10.1007/s00723-024-01678-4","url":null,"abstract":"<div><p>Nuclear magnetic resonance (NMR) investigations of the ionic liquid (IL) 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BmpyrTFSI) are presented. BmpyrTFSI is one of the most commonly used electrolytes, either as a pure liquid or in combination with other solvents and salts. We have studied its physicochemical properties by NMR diffusion, which allows us to measure independently the self-diffusion coefficients of both anions and cations: <sup>1</sup>H for the bmpyr<sup>+</sup> cation, <sup>19</sup>F for the TFSI anion and <sup>13</sup>C for both ions. The purity of the test liquid was verified by NMR spectroscopy and it was shown that there were no impurity lines in the spectra on the <sup>1</sup>H and <sup>13</sup>C nuclei. Self-diffusion coefficients of the cation and anion were measured in the temperature range of 243 to 333 K, which were used to study the mobility of the ions for comparison with the ionic conductivity. All the diffusion attenuations are described by a single component; we can conclude that neither ion pairs nor more complex conglomerates are observed in our system. We believe that the conductivity is completely determined by the self-diffusion of the ions. In addition, the agreement of our data with literature data on the temperature dependence of self-diffusion coefficients on the values of viscosity and ionic conductivity is considered. It is shown that the Stokes–Einstein relation is a poor description of the molecular mobility of this IL.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 8","pages":"785 - 794"},"PeriodicalIF":1.1,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571611","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":"Impact of γ-Irradiation on Separation of Nuclear Spin-Relaxation Mechanisms Under Magnetic Saturation in a NaF Crystal","authors":"A. M. Rochev, V. M. Mikushev, E. V. Charnaya","doi":"10.1007/s00723-024-01675-7","DOIUrl":"10.1007/s00723-024-01675-7","url":null,"abstract":"<div><p>Studies were carried out on the effect of additional continuous magnetic saturation of the NMR line on nuclear spin relaxation in a NaF single crystal before and after γ-irradiation. The times of magnetization recovery after inversion were measured at room temperature using a Bruker Avance 400 pulse spectrometer. The magnetic saturation was obtained by exciting a long additional resonance pulse. Two main contributions to relaxation for quadrupole <sup>23</sup>Na nuclei, due to spin-phonon coupling in a regular crystalline lattice and due to magnetic centers, were separated by suppressing the latter contribution. γ-irradiation was shown to enhance spin relaxation, however, the magnetic saturation does not suppress the contribution of color centers. The times corresponding to <sup>23</sup>Na relaxation due to spin-phonon coupling in a regular lattice, due to magnetic centers and color centers were evaluated. It was shown that the rate of spin–lattice relaxation for dipole <sup>19</sup>F nuclei was not affected by magnetic saturation.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 8","pages":"819 - 826"},"PeriodicalIF":1.1,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548477","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}
Anna S. Kashnik, Anastasiya N. Atnyukova, Denis S. Baranov, Sergei A. Dzuba
{"title":"DEER Study of Spatial Arrangement of Spin-Labeled Diclofenac in Lipid Bilayers of Different Composition","authors":"Anna S. Kashnik, Anastasiya N. Atnyukova, Denis S. Baranov, Sergei A. Dzuba","doi":"10.1007/s00723-024-01674-8","DOIUrl":"10.1007/s00723-024-01674-8","url":null,"abstract":"<div><p>Diclofenac is a non-steroidal anti-inflammatory drug (NSAID). Here, we use double electron–electron resonance (DEER, also known as PELDOR) to study the interaction of spin-labeled diclofenac (diclofenac-SL) with three types of model membranes consisting of palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), an equimolar mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), and this mixture with the addition of 20 mol% cholesterol. The results suggest that lipid-mediated lateral clustering of diclofenac-SL molecules occurs in all cases. For the POPC bilayer, alternative clustering takes place in two opposite leaflets, with random distribution of the molecules within the clusters. For DOPC/DPPC and DOPC/DPPC/cholesterol bilayers, diclofenac-SL molecules are separated by a distance of at least 1.4 nm. DOPC/DPPC/cholesterol bilayers are known to form nanoscale liquid disordered and liquid ordered lateral structures, the latter called lipid rafts. For this case, diclofenac-SL molecules were found to be captured by lipid rafts, forming a quasi-regular two-dimensional substructure in them with a “superlattice” parameter of ~ 3.0 nm.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 9","pages":"1145 - 1157"},"PeriodicalIF":1.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141519424","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":"Electron Spin Resonance Spectroscopy on Magnetic van der Waals Compounds","authors":"Vladislav Kataev, Bernd Büchner, Alexey Alfonsov","doi":"10.1007/s00723-024-01671-x","DOIUrl":"10.1007/s00723-024-01671-x","url":null,"abstract":"<div><p>The field of research on magnetic van der Waals compounds—a special subclass of quasi-two-dimensional materials—is currently rapidly expanding due to the relevance of these compounds to fundamental research where they serve as a playground for the investigation of different models of quantum magnetism and also in view of their unique magneto-electronic and magneto-optical properties pertinent to novel technological applications. The electron spin resonance (ESR) spectroscopy plays an important role in the exploration of the rich magnetic behavior of van der Waals compounds due to its high sensitivity to magnetic anisotropies and unprecedentedly high energy resolution that altogether enable one to obtain thorough insights into the details of the spin structure in the magnetically ordered state and the low-energy spin dynamics in the ordered and paramagnetic phases. This article provides an overview of the recent achievements in this field made by the ESR spectroscopic techniques encompassing representatives of antiferro- and ferromagnetic van der Waals compounds of different crystal structures and chemical composition as well as of a special category of these materials termed magnetic topological insulators.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 9","pages":"923 - 960"},"PeriodicalIF":1.1,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-024-01671-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548478","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}
Ilya V. Yakovlev, Evgeniy S. Papulovskiy, Aleksandr A. Shubin, Aleksandr V. Toktarev, Olga B. Lapina
{"title":"Hydration and Hydrolysis of Boron-Substituted Aluminophosphate BAPO-5 According to Solid-State NMR and DFT Calculations","authors":"Ilya V. Yakovlev, Evgeniy S. Papulovskiy, Aleksandr A. Shubin, Aleksandr V. Toktarev, Olga B. Lapina","doi":"10.1007/s00723-024-01673-9","DOIUrl":"10.1007/s00723-024-01673-9","url":null,"abstract":"<div><p>Microporous aluminophosphates (AlPOs) are prospective materials that can be used as molecular sieves and adsorbents in their pure form or catalysts and catalyst supports when some of the sites are substituted with heteroatoms. One of the approaches to create and finely tune Brønsted acid sites in AlPO is simultaneous introduction of Si and B into the framework. However, boron substitution of AlPOs is briefly studied and proceeds with difficulties. Here, we apply multinuclear solid-state nuclear magnetic resonance together with DFT calculations to investigate the behavior of aluminophosphate AlPO-5 and its boron-substituted analogue BAPO-5 upon interaction with water. We demonstrate that the structure of AlPO-5 facilitates a homogeneous distribution of water molecules and makes BAPO-5 less susceptible to hydrolysis compared to microporous AlPO-11 and BAPO-11.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 10","pages":"1245 - 1261"},"PeriodicalIF":1.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548479","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":"Crossover to XXZ Chain Spin Liquid in the Frustrated Quantum Magnet Cs(_2)CoCl(_4)","authors":"T. A. Soldatov, V. S. Edelman, A. I. Smirnov","doi":"10.1007/s00723-024-01669-5","DOIUrl":"10.1007/s00723-024-01669-5","url":null,"abstract":"<div><p>We study 25–120 GHz electron spin resonance in a quasi-two-dimensional <span>(S=)</span> 3/2 antiferromagnet on an isosceles triangular lattice Cs<span>(_2)</span>CoCl<span>(_4)</span>. Due to the frustration of the exchange interaction along the lateral sides of the triangles, the exchange network may be viewed as a quasi-one-dimensional system of weakly interacting chains. The strong single-ion anisotropy of Co<span>(^{2+})</span> allows a pseudospin <span>(s=)</span> 1/2 formulation of the problem. We observe in experiments a well-pronounced temperature crossover from the ESR of individual pseudospins with a <i>g</i>-factor of 3.3 (corresponding well to individual pseudospins <i>s</i>=1/2) to ESR spectrum shifted strongly down in frequency at the temperature range below 1 K. This shifted ESR spectrum corresponds well to the singularity at the lower boundary of the quasi-spinon continuum of an XXZ spin chain in a transverse field, calculated in theory by Bruognolo et al., in Phys Rev B 94:085136, 2016 and by Laurell et al., in Phys Rev Lett 127:037201, 2021.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 9","pages":"1137 - 1144"},"PeriodicalIF":1.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141519281","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}
A. A. Vasilev, D. Yu. Nefedov, E. V. Charnaya, Yu. A. Kumzerov, A. V. Fokin
{"title":"Impact of Porous Matrix Morphology on the Phase Diagrams in the GaInSn Alloy Under Nanoconfinement","authors":"A. A. Vasilev, D. Yu. Nefedov, E. V. Charnaya, Yu. A. Kumzerov, A. V. Fokin","doi":"10.1007/s00723-024-01672-w","DOIUrl":"10.1007/s00723-024-01672-w","url":null,"abstract":"<div><p>Gallium alloys are widespread materials in microelectronics and are promising as components of nanocomposites for using in soft robotics, wearable electronics, and sensors. Here, we present NMR studies of the impact of a particular nanoconfinement on the phase diagram for the GaInSn eutectic alloy in a porous Al<sub>2</sub>O<sub>3</sub> ceramic template with the middle pore size 11 nm. Measurements of the NMR spectra and Knight shifts were carried out for <sup>71</sup>Ga, <sup>69</sup>Ga, and <sup>115</sup>In isotopes from 180 to 310 K. The precipitation of gallium-rich segregates with crystalline structures of α- and β-Ga was found at cooling. The evolution of the NMR lines during cooling and warming evidenced the occurrence of the liquid–liquid-phase transition in the melt fraction with pronounced amount of indium. The results obtained for the GaInSn alloy embedded into the porous aluminum oxide ceramic were found to differ remarkably from the phase diagrams of the alloy confined within silica opal and glass porous matrices.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 8","pages":"795 - 804"},"PeriodicalIF":1.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141519415","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":"Automated Quantification of Lateral and Medial Temporal Lobe Volumes for Improved Diagnosis of Early Alzheimer’s Disease","authors":"Marufjon Salokhiddinov, Dharmesh Singh, Akash Gandhamal, Dileep Kumar, Elisabeth Stamou, Munojat Ismailova, Gulnora Rakhimbaeva, Dilshod Tolibov","doi":"10.1007/s00723-024-01667-7","DOIUrl":"10.1007/s00723-024-01667-7","url":null,"abstract":"<div><p>The purpose of this study was to evaluate the importance of automated lateral and medial temporal volume measurement technique for the early diagnosis of Alzheimer's disease (AD). A cross-sectional T1-weighted magnetic resonance image was obtained from 39 healthy adults and 39 patients with mild AD. The study demonstrates significant volume loss in the lateral temporal lobe (LTL) and medial temporal lobe (MTL) regions of the brain in early cases of AD, suggesting that volume loss could be used as a viable biomarker for mild AD diagnosis. Using a deep learning-based auto-segmentation network (CINet), the study accurately estimates the volumes of various LTL and MTL brain regions. Notably, higher volume loss is observed in the left MTL and LTL regions compared to the right, indicating an asymmetric impact in mild AD. The study underscores the significance of automated technique for AD diagnosis and monitoring disease progression, contributing valuable insights for potential early interventions.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 7","pages":"719 - 736"},"PeriodicalIF":1.1,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00723-024-01667-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548481","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}