Applied Magnetic Resonance最新文献_第8页

The Challenges and Opportunities of High-Spin Mn(II) EPR and ENDOR 高旋锰(II) EPR 和ENDOR 的挑战与机遇

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-22 DOI: 10.1007/s00723-024-01680-w

Peter E. Doan, Alex Drena, Ajay Sharma, Brian M. Hoffman

引用次数: 0

The Application of Hierarchical Cluster Analysis to Lignins Classification Based on Data of High-Resolution NMR and Solid-State NMR Spectra on 13C Nuclei 基于 13C 核的高分辨率 NMR 和固态 NMR 光谱数据的层次聚类分析在木质素分类中的应用

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-22 DOI: 10.1007/s00723-024-01686-4

Ilya A. Grishanovich, Yuliya A. Sypalova, Semyon L. Shestakov, Alexandr Yu. Kozhevnikov

{"title":"The Application of Hierarchical Cluster Analysis to Lignins Classification Based on Data of High-Resolution NMR and Solid-State NMR Spectra on 13C Nuclei","authors":"Ilya A. Grishanovich, Yuliya A. Sypalova, Semyon L. Shestakov, Alexandr Yu. Kozhevnikov","doi":"10.1007/s00723-024-01686-4","DOIUrl":"10.1007/s00723-024-01686-4","url":null,"abstract":"<div>Lignin is the second most abundant biological polymer on Earth with a complex chemical structure. A large amount of different technical lignins are produced as a waste product of the pulp and paper industry and are not used rationally. The study of the structure of such lignins is relevant due to their potential applications. It is important to obtain comprehensive knowledge about the structure of lignin macromolecule and to classify lignins based on it. High-resolution nuclear magnetic resonance (NMR) experiments for dissolved samples are widely used to study this biopolymer. However, this approach does not allow researching insoluble technical lignins. Solid-state NMR spectroscopy may become a solution to this problem. In this paper, we propose an approach to classify the degree of lignin alteration by clustering of solid-state spectra with hierarchical cluster analysis method. This approach is important because of the lack of direct correlations between the NMR spectra of lignins in the dissolved and solid states, which is based on experimental data.</div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 8","pages":"827 - 838"},"PeriodicalIF":1.1,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770231","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}

引用次数: 0

Automated Image Registration and Perfusion Sorting Algorithms for PREFUL MRI 用于 PREFUL MRI 的自动图像注册和灌注排序算法

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-20 DOI: 10.1007/s00723-024-01684-6

Timofei V. Taran, Olga S. Pavlova, Mikhail V. Gulyaev, Dmitry S. Dmitriev, Aleksandr G. Pistrak, Kirill N. Ryabikov, Viktor P. Tarasov, Yury A. Pirogov

{"title":"Automated Image Registration and Perfusion Sorting Algorithms for PREFUL MRI","authors":"Timofei V. Taran, Olga S. Pavlova, Mikhail V. Gulyaev, Dmitry S. Dmitriev, Aleksandr G. Pistrak, Kirill N. Ryabikov, Viktor P. Tarasov, Yury A. Pirogov","doi":"10.1007/s00723-024-01684-6","DOIUrl":"10.1007/s00723-024-01684-6","url":null,"abstract":"<div>Respiratory diseases are the leading cause of death and disabilities worldwide. Current clinical approaches are based on computed tomography and positron emission tomography which use harmful ionizing radiation and cannot be used often. Because of that, proton MRI is a promising tool for functional lung assessment. PREFUL MRI method was shown to yield promising results for future clinical use, however, no standard imaging protocols or computer programs which do not require human supervision exist. Therefore, the purpose of this study was to make a step toward automating and improving robustness of the PREFUL method. Several algorithms were designed including phase sorting for respiratory and heart cycles, image registration and lung segmentation. Ten healthy volunteers underwent PREFUL MRI study and maps of fractional ventilation (FV) and perfusion (Qquant) were calculated. The maps showed no sign of any pathology and among all healthy volunteers the mean values of FV and Qquant were 0.21 ± 0.08 and 460 ± 140 ml/min/100 ml, respectively. The obtained results are well agreed with known research data. Thus, our designed automated algorithms for PREFUL MRI can be implemented for assessing ventilation and perfusion of the lung.</div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 8","pages":"741 - 752"},"PeriodicalIF":1.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141740510","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}

引用次数: 0

Differentiation of Cinchonine and Cinchonidine Derivatives Through 13C NMR Analysis of the Quinuclidine Ring 通过对奎宁环的 13C NMR 分析区分辛可宁和辛可尼丁衍生物

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-20 DOI: 10.1007/s00723-024-01687-3

Denilson F. Oliveira, Alan R. T. Machado, Mariana G. Aguilar, Abraão J. S. Viana

{"title":"Differentiation of Cinchonine and Cinchonidine Derivatives Through 13C NMR Analysis of the Quinuclidine Ring","authors":"Denilson F. Oliveira, Alan R. T. Machado, Mariana G. Aguilar, Abraão J. S. Viana","doi":"10.1007/s00723-024-01687-3","DOIUrl":"10.1007/s00723-024-01687-3","url":null,"abstract":"<div>With a view to developing a procedure for the differentiation of cinchonine derivatives from cinchonidine derivatives by NMR analysis, experimental data on cinchonine and cinchonidine, after their dissolution in different solvents (CDCl3, CD3OD and DMSO-d6), were compared with theoretical data, originating from different methodologies: DP4, DP4+ , J-DP4 and ANN. Taking into account the lower computational consumption, as well as the greater efficiency in differentiation, the method selected was the trained artificial neural networks (ANN), which considered only the 13C data from the quinuclidine ring. The method successfully differentiated derivatives originating from OH group protection in ester and ether forms; replacement of the OH group by F and NH2; insertions of N3, 1H-1,2,3-triazol-1-yl and CH3O groups, linked to the quinoline ring; conversion of the vinyl group to the 1-benzyl-1H-1,2,3-triazol-4-yl; and of hydrogenation, dehydrogenation, and bromination of the vinyl group. In all cases the application of the ANN method succeeded in differentiation of cinchonine from cinchonidine derivatives.</div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 11","pages":"1377 - 1388"},"PeriodicalIF":1.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141740509","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}

引用次数: 0

EPR Spectroscopy of the Ground Electron State of the Fe2+ Impurity Ion in Amethyst 紫水晶中 Fe2+ 杂质离子地面电子态的 EPR 光谱分析

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-16 DOI: 10.1007/s00723-024-01683-7

V. F. Tarasov, R. B. Zaripov

引用次数: 0

Vanadyl Porphyrin: Efficient Spin Probe to Study the Alumina Surface of Supported Catalysts 钒基卟啉：研究支撑催化剂氧化铝表面的高效自旋探针

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-16 DOI: 10.1007/s00723-024-01681-9

Anna G. Chetkova, Sergey N. Trukhan, Oleg N. Martyanov

引用次数: 0

Elucidation of Organic Reaction Mechanisms Using Nuclear Magnetic Resonance: A review 利用核磁共振阐明有机反应机理：综述

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-13 DOI: 10.1007/s00723-024-01676-6

Carreras J., Caputo M., Colasurdo D., Pila M., Ruiz D., Laurella S.

{"title":"Elucidation of Organic Reaction Mechanisms Using Nuclear Magnetic Resonance: A review","authors":"Carreras J., Caputo M., Colasurdo D., Pila M., Ruiz D., Laurella S.","doi":"10.1007/s00723-024-01676-6","DOIUrl":"10.1007/s00723-024-01676-6","url":null,"abstract":"<div>Nuclear magnetic resonance (NMR), a technique mainly used for structure determination, has also been extensively used for mechanism elucidation. The study of the different steps involved in a chemical reaction is of utmost importance since it permits the optimization of reaction conditions to improve the yield of a synthesis or to obtain one possible product over another one, for example. This review is organized into two sections. Firstly, the experimental issues concerning the applications of NMR to the elucidation of reaction mechanisms are revised: advantages, limitations and challenges are discussed. The different techniques used for overcoming the difficulties concerning NMR (such as low sensitivity, peak resolution, and mixing time) are described (including stop-flow, rapid-injection, liquid chromatography-NMR, dynamic nuclear polarization, and parahydrogen-induced polarization, among others). In the second section, experiments specifically designed for obtaining mechanistic information by means of different NMR techniques are summarized: kinetic experiments, detection of reaction intermediates, isotope labeling, variable-temperature experiments, and variable-pH experiments. The main objective of this work is to give an overview on the relevance of NMR as a very useful tool for elucidating organic reaction mechanisms.</div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"55 11","pages":"1335 - 1376"},"PeriodicalIF":1.1,"publicationDate":"2024-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141609080","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}

引用次数: 0

Nuclear Overhauser Effect in Determining the Configuration of 2-Nitrofuran-3-Carboxylates Hydrazones 确定 2-硝基呋喃-3-羧酸肼构型的核过豪瑟效应

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-11 DOI: 10.1007/s00723-024-01677-5

Kirill A. Gomonov, Vasilii V. Pelipko, Igor A. Litvinov, Ruslan I. Baichurin, Sergey V. Makarenko

引用次数: 0

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 Azurin 中 1 型铜位点第二球变体的 1H HYSCORE 研究：突变对 Cys112 CβH2 质子超细耦合的影响

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-09 DOI: 10.1007/s00723-024-01665-9

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>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 CβH2 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 Cβ 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 SC112 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 SC112—despite previous observations of a significant increase in S character in the SOMO, demonstrating a more complex relationship between Cβ–1H hyperfine and the unpaired spin density of SC112 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 CβH2 protons with the large isotropic couplings resulted from aiso strain produced by the fluctuations of the Cβ‒H2 group orientation within θ ~ ± 2° degrees around the most populated conformation.</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}

引用次数: 0

Molecular Mobility Study of 1-Butyl-1-Methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquid by NMR Diffusometry 利用核磁共振扩散仪研究 1-丁基-1-甲基吡咯烷鎓双(三氟甲基磺酰基)亚胺离子液体的分子迁移率

IF 1.1 4区物理与天体物理

Applied Magnetic Resonance Pub Date : 2024-07-08 DOI: 10.1007/s00723-024-01678-4

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>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: 1H for the bmpyr+ cation, 19F for the TFSI anion and 13C 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 1H and 13C 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.</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}

引用次数: 0