Journal of Magnetic Resonance Open最新文献_第6页

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 : 2024-12-01 Epub 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, 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":"2024-12-01","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

Hyperpolarization of [13C]formate using parahydrogen 使用对氢使[13C]甲酸盐超极化

IF 2.624

Journal of Magnetic Resonance Open Pub Date : 2024-12-01 Epub Date: 2024-11-17 DOI: 10.1016/j.jmro.2024.100176

Dudari B. Burueva , Sergey V. Sviyazov , Nikita V. Chukanov , Nazim R. Mustafin , Oleg G. Salnikov , Eduard Y. Chekmenev , Kirill V. Kovtunov , Igor V. Koptyug

引用次数: 0

Hyperpolarization and sensitivity in nuclear magnetic resonance 核磁共振中的超极化和灵敏度

IF 2.624

Journal of Magnetic Resonance Open Pub Date : 2024-12-01 Epub Date: 2024-11-16 DOI: 10.1016/j.jmro.2024.100172

Karel Kouřil , Benno Meier

引用次数: 0

Natural abundance 195Pt-13C correlation NMR spectroscopy on surfaces enabled by fast MAS dynamic nuclear polarization 利用快速 MAS 动态核极化实现表面天然丰度 195Pt-13C 相关 NMR 光谱分析

IF 2.624

Journal of Magnetic Resonance Open Pub Date : 2024-12-01 Epub Date: 2024-10-09 DOI: 10.1016/j.jmro.2024.100167

Zhuoran Wang , Thomas C. Robinson , Domenico Gioffrè , Rochlitz Lukas , David Gajan , Aaron J. Rossini , Christophe Copéret , Anne Lesage

{"title":"Natural abundance 195Pt-13C correlation NMR spectroscopy on surfaces enabled by fast MAS dynamic nuclear polarization","authors":"Zhuoran Wang , Thomas C. Robinson , Domenico Gioffrè , Rochlitz Lukas , David Gajan , Aaron J. Rossini , Christophe Copéret , Anne Lesage","doi":"10.1016/j.jmro.2024.100167","DOIUrl":"10.1016/j.jmro.2024.100167","url":null,"abstract":"<div><div>Surface organometallic chemistry has developed as an effective strategy for the rational design and synthesis of well-defined, single-site Pt-based heterogeneous catalysts. Given its high sensitivity to changes in electronic structure, <sup>195</sup>Pt solid-state NMR spectroscopy offers a unique approach to investigate the chemical structure and local environment of Pt surface sites, providing invaluable insights for establishing structure-activity relationships. However, this approach is typically hindered by severe sensitivity issues, due to the low loading of Pt sites and the often-encountered large <sup>195</sup>Pt chemical shift anisotropies. To overcome this limitation, <sup>195</sup>Pt NMR signature of surface metal centers can be indirectly detected through protons. Indirect detection on <sup>13</sup>C spins, has also been demonstrated to be feasible by combining isotopic labeling with dynamic nuclear polarization (DNP). Here, we extend this methodology to a supported Pt complex at natural abundance. The material was prepared by grafting <strong>(COD)PtMeOSi(O<em>t</em>Bu)<sub>3</sub></strong> (COD = 1,5-cyclooctadiene, Me = methyl and <em>t</em>Bu = <em>tert</em>‑butyl) onto partially dehydroxylated silica. DNP enhanced two-dimensional through-bond <sup>13</sup>C{<sup>195</sup>Pt} heteronuclear correlation experiments were successfully implemented at fast magic angle spinning. They enabled the detection of the 0.37 % NMR-responsive surface species, thereby showcasing the remarkable sensitivity of this approach and its broad applicability. Key bonding information was obtained by measuring the correlated <sup>13</sup>C and <sup>195</sup>Pt isotopic chemical shifts as well as <sup>1</sup><em>J</em>(<sup>13</sup>C-<sup>195</sup>Pt) coupling constants, confirming directly the coordination structure of the surface Pt sites.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100167"},"PeriodicalIF":2.624,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434013","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 : 2024-12-01 Epub 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 , Hadi Lotfi , Michal Kern , Frederik Dreyer , Mazin Jouda , Jan. G. Korvink , Bernhard Blümich , 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 0.25T. 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 500nL 10mM 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":"2024-12-01","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

Nuclear hyperpolarization in electron-transfer proteins: Revealing unexpected light-induced 15N signals with field-cycling magic-angle spinning NMR 电子传递蛋白中的核超极化：用场循环魔角旋转 NMR 揭示意想不到的光诱导 15N 信号

IF 2.624

Journal of Magnetic Resonance Open Pub Date : 2024-12-01 Epub Date: 2024-10-05 DOI: 10.1016/j.jmro.2024.100168

Patrick Kurle-Tucholski , Luca Gerhards , Yonghong Ding , Yunmi Kim , Irina S. Anisimova , A. Alia , Ilia A. Solov'yov , Jörg Matysik

{"title":"Nuclear hyperpolarization in electron-transfer proteins: Revealing unexpected light-induced 15N signals with field-cycling magic-angle spinning NMR","authors":"Patrick Kurle-Tucholski , Luca Gerhards , Yonghong Ding , Yunmi Kim , Irina S. Anisimova , A. Alia , Ilia A. Solov'yov , Jörg Matysik","doi":"10.1016/j.jmro.2024.100168","DOIUrl":"10.1016/j.jmro.2024.100168","url":null,"abstract":"<div><div>The solid-state photo-CIDNP (photo-chemically induced dynamic nuclear polarization) effect allows for nuclear hyperpolarization, i.e., non-Boltzmann nuclear spin population. The effect relies on the light-induced formation of a spin-correlated radical pair (SCRP) and has been observed in various photosynthetic reaction center (RC) proteins and flavin-containing light, oxygen, voltage (LOV) proteins. Both systems exhibit strongly enhanced NMR signals originating from the electron transfer partners. Here, we present experimental data on the magnetic field dependence of the <sup>15</sup>N solid-state photo-CIDNP effect in both phototropin LOV1 C57S from <em>Chlamydomonas reinhardtii</em> and the bacterial photosynthetic RC from <em>Rhodobacter sphaeroides.</em> Using a pneumatic field-cycling system, samples containing a frozen solution of the proteins are explored between 0.25 T and 9.4 T. Both systems yield hyperpolarized <sup>15</sup>N NMR signals across the entire magnetic field range originating from the electron transfer moieties. Also, in both systems, hyperpolarized signals from unexpected positions are detected between 1.0 T and 2.0 T: position N-1 of the flavin in the LOV1 protein and the τ-N of the axial magnesium-coordinating histidine of the donor. A first attempt to explain the occurrence of these unexpected signals based on quantum chemical calculations is presented.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100168"},"PeriodicalIF":2.624,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427347","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

13C-Formate as an indirect low-temperature 1H lineshape polarimeter 作为间接低温 1H 线形偏振计的 13C 甲酸酯

IF 2.624

Journal of Magnetic Resonance Open Pub Date : 2024-12-01 Epub Date: 2024-09-23 DOI: 10.1016/j.jmro.2024.100162

Stuart J. Elliott , Quentin Stern, Sami Jannin

{"title":"13C-Formate as an indirect low-temperature 1H lineshape polarimeter","authors":"Stuart J. Elliott , Quentin Stern, Sami Jannin","doi":"10.1016/j.jmro.2024.100162","DOIUrl":"10.1016/j.jmro.2024.100162","url":null,"abstract":"<div><div><sup>1</sup>H polarization quantification is important for dissolution-dynamic nuclear polarization (<em>d</em>DNP) but can be cumbersome due to the requirement of acquiring thermal equilibrium signals and measurements that are complicated by large background signals. <sup>1</sup>H nuclear magnetic resonance (NMR) spectra can also be deleteriously influenced by line distortions linked with radiation damping from <sup>1</sup>H DNP and cannot be used for accurate calculation of <sup>1</sup>H polarization. Determining <sup>1</sup>H polarization via immediate <sup>13</sup>C lineshape analysis of a simple molecule removes such complications. We present <sup>13</sup>C-sodium formate as a straightforward system for indirect <sup>1</sup>H polarimetry. The <sup>13</sup>C NMR spectra acquired under <em>d</em>DNP conditions have distinct features that are readily reproduced with <sup>13</sup>C lineshape simulations. <sup>1</sup>H polarizations built-up during <sup>1</sup>H DNP were indirectly inferred by fitting simulations to <sup>13</sup>C lineshapes. We provide the <em>MATLAB</em> scripts used for <sup>13</sup>C lineshape analysis in order that the method can be readily implemented in other laboratories.</div></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"21 ","pages":"Article 100162"},"PeriodicalIF":2.624,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427292","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

Creating high, portable proton polarization with photo-excited triplet DNP 利用光激发三重 DNP 创建高便携质子极化

IF 2.624

Journal of Magnetic Resonance Open Pub Date : 2024-09-01 Epub Date: 2024-08-22 DOI: 10.1016/j.jmro.2024.100159

P. Hautle, W.Th. Wenckebach

{"title":"Creating high, portable proton polarization with photo-excited triplet DNP","authors":"P. Hautle, W.Th. Wenckebach","doi":"10.1016/j.jmro.2024.100159","DOIUrl":"10.1016/j.jmro.2024.100159","url":null,"abstract":"<div><p>Dynamic nuclear polarization (DNP) is a powerful tool to polarize nuclear spins and enhance the intensity of their magnetic resonance signal. For DNP a sample is doped with an agent providing unpaired electron spins. Then the sample is cooled in a strong magnetic field to polarize these electron spins and a microwave field is applied to transfer this polarization to the nuclear spins. While DNP is very efficient, it has two inherent issues: the electron spins needed to polarize the nuclear spins are also the main source of polarization decay. Furthermore, polarizing the electron spins requires strong magnets and powerful cryogenics, that may obstruct further use of the polarized nuclear spins.</p><p>These issues can be addressed by using the electron spin of photo-excited triplet states for DNP. After DNP the light creating the electron spins can be shut off, thus eliminating the main source of decay of the nuclear polarization. Moreover, for some well-chosen molecules the photo-excitation process creates the triplet state in a highly polarized state, so magnets and cryogenics can be significantly simplified.</p><p>The present article presents the state of the art of producing a high proton polarization – up to 0.80 – with a long lifetime – typically 50 h at liquid nitrogen temperature and in a field of 0.75 T – using the photo-excited triplet state of pentacene in a naphthalene host. It describes sample preparation, experimental equipment and procedures required to obtain this result, as well the theoretical background required to maximize the polarization transfer from the triplet spins to the proton spins and to optimize the photo-excitation process. It finishes with methods for long-distance transport and final application of polarized samples.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"20 ","pages":"Article 100159"},"PeriodicalIF":2.624,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000141/pdfft?md5=002d182c52f0ebba51698515177991e9&pid=1-s2.0-S2666441024000141-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142041289","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

Understanding magnetic fields, for NMR/MRI 了解磁场，用于核磁共振/MRI

IF 2.624

Journal of Magnetic Resonance Open Pub Date : 2024-09-01 Epub Date: 2024-07-29 DOI: 10.1016/j.jmro.2024.100158

Mark S. Conradi

引用次数: 0

Automated hyperpolarized 129Xe gas generator for nuclear magnetic resonance spectroscopy and imaging applications 用于核磁共振光谱和成像应用的自动超极化 129Xe 气体发生器

IF 2.624

Journal of Magnetic Resonance Open Pub Date : 2024-09-01 Epub Date: 2024-06-26 DOI: 10.1016/j.jmro.2024.100154

Mineyuki Hattori , Takashi Hiraga , Kazuhiro Homma , Norio Ohtake

{"title":"Automated hyperpolarized 129Xe gas generator for nuclear magnetic resonance spectroscopy and imaging applications","authors":"Mineyuki Hattori , Takashi Hiraga , Kazuhiro Homma , Norio Ohtake","doi":"10.1016/j.jmro.2024.100154","DOIUrl":"https://doi.org/10.1016/j.jmro.2024.100154","url":null,"abstract":"<div><p>We describe a method and an apparatus for producing hyperpolarized (HP) Xe gas of high concentration without Xe condensation. The HP Xe generator works under atmospheric pressure and employs a quasi-continuous method to provide a continuous supply of HP Xe gas by adopting technologies for supplying a highly pure gas, a gas control system and precise pressure control. The apparatus has a glass cell containing solid Rb metal and solid Xe in vacuum at a low temperature and is heated so that the Xe becomes a gas and Rb exists in a gas-liquid mixture. Then a magnetic field is applied with laser beam irradiation to produce polarized Xe gas of high concentration. The device was evaluated using a 2T magnetic resonance imaging (MRI) scanner. Long-term experimental operation demonstrated the continuous collection of 30 ml syringes of HP Xe gas with a sufficient polarization rate for fast one scan acquisition. A practical device for the automated manufacture of HP <sup>129</sup>Xe gas was thus successfully developed.</p></div>","PeriodicalId":365,"journal":{"name":"Journal of Magnetic Resonance Open","volume":"20 ","pages":"Article 100154"},"PeriodicalIF":2.624,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666441024000098/pdfft?md5=b9d93058d60dbb47913e59da366288d6&pid=1-s2.0-S2666441024000098-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583180","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