1
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Negroni M, Kurzbach D. Missing Pieces in Structure Puzzles: How Hyperpolarized NMR Spectroscopy Can Complement Structural Biology and Biochemistry. Chembiochem 2023; 24:e202200703. [PMID: 36624049 DOI: 10.1002/cbic.202200703] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/11/2023]
Abstract
Structure determination lies at the heart of many biochemical research programs. However, the "giants": X-ray diffraction, electron microscopy, molecular dynamics simulations, and nuclear magnetic resonance, among others, leave quite a few dark spots on the structural pictures drawn of proteins, nucleic acids, membranes, and other biomacromolecules. For example, structural models under physiological conditions or of short-lived intermediates often remain out of reach of the established experimental methods. This account frames the possibility of including hyperpolarized, that is, dramatically signal-enhanced NMR in existing workflows to fill these spots with detailed depictions. We highlight how integrating methods based on dissolution dynamic nuclear polarization can provide valuable complementary information about formerly inaccessible conformational spaces for many systems. A particular focus will be on hyperpolarized buffers to facilitate the NMR structure determination of challenging systems.
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Affiliation(s)
- Mattia Negroni
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Währinger Str. 38, 1090, Vienna, Austria
| | - Dennis Kurzbach
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Währinger Str. 38, 1090, Vienna, Austria
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2
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Michaelis VK, Keeler EG, Bahri S, Ong TC, Daviso E, Colvin MT, Griffin RG. Biradical Polarizing Agents at High Fields. J Phys Chem B 2022; 126:7847-7856. [PMID: 36194539 PMCID: PMC9886493 DOI: 10.1021/acs.jpcb.2c03985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The sensitivity enhancements available from dynamic nuclear polarization (DNP) are rapidly reshaping the research landscape and expanding the field of nuclear magnetic resonance (NMR) spectroscopy as a tool for solving complex chemical and structural problems. The past decade has seen considerable advances in this burgeoning method, while efforts to further improve its capabilities continue along many avenues. In this report, we examine the influence of static magnetic field strength and temperature on the reported 1H DNP enhancements from three conventional organic biradicals: TOTAPOL, AMUPol, and SPIROPOL. In contrast to the conventional wisdom, our findings show that at liquid nitrogen temperatures and 700 MHz/460.5 GHz, these three bisnitroxides all provide similar 1H DNP enhancements, ε ≈ 60. Furthermore, we investigate the influence of temperature, microwave power, magnetic field strength, and protein sample deuteration on the NMR experimental results.
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Affiliation(s)
- Vladimir K. Michaelis
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Department of Chemistry, University of Alberta, Edmonton T6G 2G2 Alberta, Canada
| | - Eric G. Keeler
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; New York Structural Biology Center, New York 10027, New York, United States
| | - Salima Bahri
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht 3584CH, The Netherlands
| | - Ta-Chung Ong
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles 90095 California, United States
| | - Eugenio Daviso
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Department of Scientific Support and Applications Development, Covaris LLC, Woburn 01801 Massachusetts, United States
| | - Michael T. Colvin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States; Ortho Clinical Diagnostics, Rochester 14626 New York, United States
| | - Robert G. Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139 Massachusetts, United States
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3
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Elliott SJ, Stern Q, Ceillier M, El Daraï T, Cousin SF, Cala O, Jannin S. Practical dissolution dynamic nuclear polarization. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2021; 126-127:59-100. [PMID: 34852925 DOI: 10.1016/j.pnmrs.2021.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 06/13/2023]
Abstract
This review article intends to provide insightful advice for dissolution-dynamic nuclear polarization in the form of a practical handbook. The goal is to aid research groups to effectively perform such experiments in their own laboratories. Previous review articles on this subject have covered a large number of useful topics including instrumentation, experimentation, theory, etc. The topics to be addressed here will include tips for sample preparation and for checking sample health; a checklist to correctly diagnose system faults and perform general maintenance; the necessary mechanical requirements regarding sample dissolution; and aids for accurate, fast and reliable polarization quantification. Herein, the challenges and limitations of each stage of a typical dissolution-dynamic nuclear polarization experiment are presented, with the focus being on how to quickly and simply overcome some of the limitations often encountered in the laboratory.
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Affiliation(s)
- Stuart J Elliott
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Quentin Stern
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Morgan Ceillier
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Théo El Daraï
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Samuel F Cousin
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Olivier Cala
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Sami Jannin
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France.
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4
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Nevzorov AA, Marek A, Milikisiyants S, Smirnov AI. Characterization of photonic band resonators for DNP NMR of thin film samples at 7 T magnetic field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 323:106893. [PMID: 33418455 PMCID: PMC8362290 DOI: 10.1016/j.jmr.2020.106893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
Polarization of nuclear spins via Dynamic Nuclear Polarization (DNP) relies on generating sufficiently high mm-wave B1e fields over the sample, which could be achieved by developing suitable resonance structures. Recently, we have introduced one-dimensional photonic band gap (1D PBG) resonators for DNP and reported on prototype devices operating at ca. 200 GHz electron resonance frequency. Here we systematically compare the performance of five (5) PBG resonators constructed from various alternating dielectric layers by monitoring the DNP effect on natural-abundance 13C spins in synthetic diamond microparticles embedded into a commercial polyester-based lapping film of just 3 mil (76 μm) thickness. An odd-numbered configuration of dielectric layers for 1D PBG resonator was introduced to achieve further B1e enhancements. Among the PBG configurations tested, combinations of high-ε perovskite LiTaO3 together with AlN as well as AlN with optical quartz wafers have resulted in ca. 40 to over 50- fold gains in the average mm-wave power over the sample vs. the mirror-only configuration. The results are rationalized in terms of the electromagnetic energy distribution inside the resonators obtained analytically and from COMSOL simulations. It was found that average of B1e2 over the sample strongly depends on the arrangement of the dielectric layers that are the closest to the sample, which favors odd-numbered PBG resonator configurations for their use in DNP.
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Affiliation(s)
- Alexander A Nevzorov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| | - Antonin Marek
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Sergey Milikisiyants
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
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5
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Lim BJ, Ackermann BE, Debelouchina GT. Targetable Tetrazine-Based Dynamic Nuclear Polarization Agents for Biological Systems. Chembiochem 2020; 21:1315-1319. [PMID: 31746101 PMCID: PMC7445144 DOI: 10.1002/cbic.201900609] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Indexed: 12/13/2022]
Abstract
Dynamic nuclear polarization (DNP) has shown great promise as a tool to enhance the nuclear magnetic resonance signals of proteins in the cellular environment. As sensitivity increases, the ability to select and efficiently polarize a specific macromolecule over the cellular background has become desirable. Herein, we address this need and present a tetrazine-based DNP agent that can be targeted selectively to proteins containing the unnatural amino acid (UAA) norbornene-lysine. This UAA can be introduced efficiently into the cellular milieu by genetic means. Our approach is bio-orthogonal and easily adaptable to any protein of interest. We illustrate the scope of our methodology and investigate the DNP transfer mechanisms in several biological systems. Our results shed light on the complex polarization-transfer pathways in targeted DNP and ultimately pave the way to selective DNP-enhanced NMR spectroscopy in both bacterial and mammalian cells.
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Affiliation(s)
- Byung Joon Lim
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Bryce E. Ackermann
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Galia T. Debelouchina
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
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6
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Jawla SK, Griffin RG, Mastovsky IA, Shapiro MA, Temkin RJ. Second Harmonic 527-GHz Gyrotron for DNP-NMR: Design and Experimental Results. IEEE TRANSACTIONS ON ELECTRON DEVICES 2020; 67:328-334. [PMID: 32099264 PMCID: PMC7040565 DOI: 10.1109/ted.2019.2953658] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report the design and experimental demonstration of a frequency tunable terahertz gyrotron at 527 GHz built for an 800 MHz Dynamic Nuclear Polarization enhanced Nuclear Magnetic Resonance (DNP-NMR) spectrometer. The gyrotron is designed at the second harmonic (ω = 2ω c) of the electron cyclotron frequency. It produces up to 9.3 W continuous microwave (CW) power at 527.2 GHz frequency using a diode type electron gun operating at V = 16.65 kV, Ib = 110 mA in a TE11,2,1 mode, corresponding to an efficiency of ~0.5%. The gyrotron is tunable within ~ 0.4 GHz by combining voltage and magnetic field tuning. The gyrotron has an internal mode converter that produces a Gaussian-like beam that couples to the HE11 mode of an internal 12 mm i.d. corrugated waveguide periscope assembly leading up to the output window. An external corrugated waveguide transmission line system is built including a corrugated taper from 12 mm to 16 mm i.d. waveguide followed by 3 m of the 16 mm i.d. waveguide The microwave beam profile is measured using a pyroelectric camera showing ~ 84% HE11 mode content.
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Affiliation(s)
- Sudheer K Jawla
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Robert G Griffin
- Department of Chemistry and the Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Ivan A Mastovsky
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Michael A Shapiro
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Richard J Temkin
- Department of Physics and the Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139
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7
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Kaminker I. Recent Advances in Magic Angle Spinning‐Dynamic Nuclear Polarization Methodology. Isr J Chem 2019. [DOI: 10.1002/ijch.201900092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Ilia Kaminker
- School of ChemistryTel Aviv University Ramat Aviv 6997801 Tel Aviv Israel
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8
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Reese M, George C, Yang C, Jawla S, Grün JT, Schwalbe H, Redfield C, Temkin RJ, Griffin RG. Modular, triple-resonance, transmission line DNP MAS probe for 500 MHz/330 GHz. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 307:106573. [PMID: 31505305 PMCID: PMC6766420 DOI: 10.1016/j.jmr.2019.106573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
We describe the design and construction of a modular, triple-resonance, fully balanced, DNP-MAS probe based on transmission line technology and its integration into a 500 MHz/330 GHz DNP-NMR spectrometer. A novel quantitative probe design and characterization strategy is developed and employed to achieve optimal sensitivity, RF homogeneity and excellent isolation between channels. The resulting three channel HCN probe has a modular design with each individual, swappable module being equipped with connectorized, transmission line ports. This strategy permits attachment of a mating connector that facilitates accurate impedance measurements at these ports and allows characterization and adjustment (e.g. for balancing or tuning/matching) of each component individually. The RF performance of the probe is excellent; for example, the 13C channel attains a Rabi frequency of 280 kHz for a 3.2 mm rotor. In addition, a frequency tunable 330 GHz gyrotron operating at the second harmonic of the electron cyclotron frequency was developed for DNP applications. Careful alignment of the corrugated waveguide led to minimal loss of the microwave power, and an enhancement factor ε = 180 was achieved for U-13C urea in the glassy matrix at 80 K. We demonstrated the operation of the system with acquisition of multidimensional spectra of cross-linked lysozyme crystals which are insoluble in glycerol-water mixtures used for DNP and samples of RNA.
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Affiliation(s)
- Marcel Reese
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Christy George
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Chen Yang
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Sudheer Jawla
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - J Tassilo Grün
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-Universität Frankfurt, 60438 Frankfurt, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-Universität Frankfurt, 60438 Frankfurt, Germany
| | - Christina Redfield
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Richard J Temkin
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Robert G Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
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9
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Sergeyev IV, Aussenac F, Purea A, Reiter C, Bryerton E, Retzloff S, Hesler J, Tometich L, Rosay M. Efficient 263 GHz magic angle spinning DNP at 100 K using solid-state diode sources. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 100:63-69. [PMID: 30965254 DOI: 10.1016/j.ssnmr.2019.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 05/03/2023]
Abstract
The development of new, high-frequency solid-state diode sources capable of operating at 263 GHz, together with an optimized stator design for improved millimeter-wave coupling to the NMR sample, have enabled low-power DNP experiments at 263 GHz/400 MHz. With 250 mW output power, signal enhancements as high as 120 are achieved on standard samples - approximately 1/3 of the maximal enhancement available with high-power gyrotrons under similar conditions. Diode-based sources have a number of advantages over vacuum tube devices: they emit a pure mode, can be rapidly frequency-swept over a wide range of frequencies, have reproducible output power over this range, and have excellent output stability. By virtue of their small size, low thermal footprint, and lack of facility requirements, solid-state diodes are also considerably cheaper to operate and maintain than high-power vacuum tube devices. In light of these features, and anticipating further improvements in terms of available output power, solid-state diodes are likely to find widespread use in DNP and contribute to further advances in the field.
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Affiliation(s)
- Ivan V Sergeyev
- Bruker BioSpin Corp., 15 Fortune Drive, Billerica, MA, 01821, USA.
| | - Fabien Aussenac
- Bruker France S.A.S., 34 Rue de l'Industrie, 67160, Wissembourg, France
| | - Armin Purea
- Bruker BioSpin GmbH, Silberstreifen 4, 76287, Rheinstetten, Germany
| | - Christian Reiter
- Bruker BioSpin GmbH, Silberstreifen 4, 76287, Rheinstetten, Germany
| | - Eric Bryerton
- Virginia Diodes Inc., 979 2(nd) St. SE, Charlottesville, VA, 22902, USA
| | - Steven Retzloff
- Virginia Diodes Inc., 979 2(nd) St. SE, Charlottesville, VA, 22902, USA
| | - Jeffrey Hesler
- Virginia Diodes Inc., 979 2(nd) St. SE, Charlottesville, VA, 22902, USA
| | - Leo Tometich
- Bruker BioSpin Corp., 15 Fortune Drive, Billerica, MA, 01821, USA
| | - Melanie Rosay
- Bruker BioSpin Corp., 15 Fortune Drive, Billerica, MA, 01821, USA
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10
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Judge PT, Sesti EL, Saliba EP, Alaniva N, Halbritter T, Sigurdsson ST, Barnes AB. Sensitivity analysis of magic angle spinning dynamic nuclear polarization below 6 K. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 305:51-57. [PMID: 31212198 DOI: 10.1016/j.jmr.2019.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/28/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
Dynamic nuclear polarization (DNP) improves signal-to-noise in nuclear magnetic resonance (NMR) spectroscopy. Signal-to-noise in NMR can be further improved with cryogenic sample cooling. Whereas MAS DNP is commonly performed between 25 and 110 K, sample temperatures below 6 K lead to further improvements in sensitivity. Here, we demonstrate that solid effect MAS DNP experiments at 6 K, using trityl, yield 3.2× more sensitivity compared to 90 K. Trityl with solid effect DNP at 6 K yields substantially more signal to noise than biradicals and cross effect DNP. We also characterize cross effect DNP with AMUPol and TEMTriPol-1 biradicals for DNP magic angle spinning at temperatures below 6 K and 7 Tesla. DNP enhancements determined from microwave on/off intensities are 253 from AMUPol and 49 from TEMTriPol-1. The higher thermal Boltzmann polarization at 6 K compared to 298 K, combined with these enhancements, should result in 10,000× signal gain for AMUPol and 2000× gain for TEMTriPol-1. However, we show that AMUPol reduces signal in the absence of microwaves by 90% compared to 41% by TEMTriPol-1 at 7 Tesla as the result of depolarization and other detrimental paramagnetic effects. AMUPol still yields the highest signal-to-noise improvement per unit time between the cross effect radicals due to faster polarization buildup (T1DNP = 4.3 s and 36 s for AMUPol and TEMTriPol-1, respectively). Overall, AMUPol results in 2.5× better sensitivity compared to TEMTriPol-1 in MAS DNP experiments performed below 6 K at 7 T. Trityl provides 6.0× more sensitivity than TEMTriPol-1 and 1.9× more than AMUPol at 6 K, thus yielding the greatest signal-to-noise per unit time among all three radicals. A DNP enhancement profile of TEMTriPol-1 recorded with a frequency-tunable custom-built gyrotron oscillator operating at 198 GHz is also included. It is determined that at 7 T below 6 K a microwave power level of 0.6 W incident on the sample is sufficient to saturate the cross effect mechanism using TEMTriPol-1, yet increasing the power level up to 5 W results in higher improvements in DNP sensitivity with AMUPol. These results indicate MAS DNP below 6 K will play a prominent role in ultra-sensitive NMR spectroscopy in the future.
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Affiliation(s)
- Patrick T Judge
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA; Department of Biochemistry, Biophysics & Structural Biology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Erika L Sesti
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Edward P Saliba
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Nicholas Alaniva
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Thomas Halbritter
- Department of Chemistry, University of Iceland, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland
| | - Snorri Th Sigurdsson
- Department of Chemistry, University of Iceland, Science Institute, Dunhaga 3, 107 Reykjavik, Iceland
| | - Alexander B Barnes
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA.
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11
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Purea A, Reiter C, Dimitriadis AI, de Rijk E, Aussenac F, Sergeyev I, Rosay M, Engelke F. Improved waveguide coupling for 1.3 mm MAS DNP probes at 263 GHz. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 302:43-49. [PMID: 30953925 DOI: 10.1016/j.jmr.2019.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 06/09/2023]
Abstract
We consider the geometry of a radially irradiated microwave beam in MAS DNP NMR probes and its impact on DNP enhancement. Two related characteristic features are found to be relevant: (i) the focus of the microwave beam on the DNP MAS sample and (ii) the microwave magnetic field magnitude in the sample. We present a waveguide coupler setup that enables us to significantly improve beam focus and field magnitude in 1.3 mm MAS DNP probes at a microwave frequency of 263 GHz, which results in an increase of the DNP enhancement by a factor of 2 compared to previous standard hardware setups. We discuss the implications of improved coupling and its potential to enable cutting-edge applications, such as pulsed high-field DNP and the use of low-power solid-state microwave sources.
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12
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Scott FJ, Alaniva N, Golota NC, Sesti EL, Saliba EP, Price LE, Albert BJ, Chen P, O'Connor RD, Barnes AB. A versatile custom cryostat for dynamic nuclear polarization supports multiple cryogenic magic angle spinning transmission line probes. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 297:23-32. [PMID: 30342370 DOI: 10.1016/j.jmr.2018.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/29/2018] [Accepted: 10/02/2018] [Indexed: 06/08/2023]
Abstract
Dynamic nuclear polarization (DNP) with cryogenic magic angle spinning (MAS) provides significant improvements in NMR sensitivity, yet presents unique technical challenges. Here we describe a custom cryostat and suite of NMR probes capable of manipulating nuclear spins with multi-resonant radiofrequency circuits, cryogenic spinning below 6 K, sample exchange, and microwave coupling for DNP. The corrugated waveguide and six transfer lines needed for DNP and cryogenic spinning functionality are coupled to the probe from the top of the magnet. Transfer lines are vacuum-jacketed and provide bearing and drive gas, variable temperature fluid, two exhaust pathways, and a sample ejection port. The cryostat thermally isolates the magnet bore, thereby protecting the magnet and increasing cryogen efficiency. This novel design supports cryogenic MAS-DNP performance over an array of probes without altering DNP functionality. We present three MAS probes (two supporting 3.2 mm rotors and one supporting 9.5 mm rotors) interfacing with the single cryostat. Mechanical details, transmission line radio frequency design, and performance of the cryostat and three probes are described.
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Affiliation(s)
- Faith J Scott
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Nicholas Alaniva
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Natalie C Golota
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Erika L Sesti
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Edward P Saliba
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Lauren E Price
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Brice J Albert
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Pinhui Chen
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA; Department of Physics, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Robert D O'Connor
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Alexander B Barnes
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA.
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13
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Ardenkjaer-Larsen JH, Bowen S, Petersen JR, Rybalko O, Vinding MS, Ullisch M, Nielsen NC. Cryogen-free dissolution dynamic nuclear polarization polarizer operating at 3.35 T, 6.70 T, and 10.1 T. Magn Reson Med 2018; 81:2184-2194. [PMID: 30357898 DOI: 10.1002/mrm.27537] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 08/26/2018] [Accepted: 08/27/2018] [Indexed: 12/27/2022]
Abstract
PURPOSE A novel dissolution dynamic nuclear polarization (dDNP) polarizer platform is presented. The polarizer meets a number of key requirements for in vitro, preclinical, and clinical applications. METHOD It uses no liquid cryogens, operates in continuous mode, accommodates a wide range of sample sizes up to and including those required for human studies, and is fully automated. RESULTS It offers a wide operational window both in terms of magnetic field, up to 10.1 T, and temperature, from room temperature down to 1.3 K. The polarizer delivers a 13 C liquid state polarization for [1-13 C]pyruvate of 70%. The build-up time constant in the solid state is approximately 1200 s (20 minutes), allowing a sample throughput of at least one sample per hour including sample loading and dissolution. CONCLUSION We confirm the previously reported strong field dependence in the range 3.35 to 6.7 T, but see no further increase in polarization when increasing the magnetic field strength to 10.1 T for [1-13 C]pyruvate and trityl. Using a custom dry magnet, cold head and recondensing, closed-cycle cooling system, combined with a modular DNP probe, and automation and fluid handling systems, we have designed a unique dDNP system with unrivalled flexibility and performance.
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Affiliation(s)
- Jan Henrik Ardenkjaer-Larsen
- Department of Electrical Engineering, Center for Hyperpolarization in Magnetic Resonance, Technical University of Denmark, Kgs. Lyngby, Denmark.,GE Healthcare, Brøndby, Denmark
| | - Sean Bowen
- Department of Electrical Engineering, Center for Hyperpolarization in Magnetic Resonance, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Jan Raagaard Petersen
- Department of Electrical Engineering, Center for Hyperpolarization in Magnetic Resonance, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Oleksandr Rybalko
- Department of Electrical Engineering, Center for Hyperpolarization in Magnetic Resonance, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Mads Sloth Vinding
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Marcus Ullisch
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Niels Chr Nielsen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Aarhus, Denmark
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14
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Jaudzems K, Polenova T, Pintacuda G, Oschkinat H, Lesage A. DNP NMR of biomolecular assemblies. J Struct Biol 2018; 206:90-98. [PMID: 30273657 DOI: 10.1016/j.jsb.2018.09.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/13/2018] [Accepted: 09/27/2018] [Indexed: 11/30/2022]
Abstract
Dynamic Nuclear Polarization (DNP) is an effective approach to alleviate the inherently low sensitivity of solid-state NMR (ssNMR) under magic angle spinning (MAS) towards large-sized multi-domain complexes and assemblies. DNP relies on a polarization transfer at cryogenic temperatures from unpaired electrons to adjacent nuclei upon continuous microwave irradiation. This is usually made possible via the addition in the sample of a polarizing agent. The first pioneering experiments on biomolecular assemblies were reported in the early 2000s on bacteriophages and membrane proteins. Since then, DNP has experienced tremendous advances, with the development of extremely efficient polarizing agents or with the introduction of new microwaves sources, suitable for NMR experiments at very high magnetic fields (currently up to 900 MHz). After a brief introduction, several experimental aspects of DNP enhanced NMR spectroscopy applied to biomolecular assemblies are discussed. Recent demonstration experiments of the method on viral capsids, the type III and IV bacterial secretion systems, ribosome and membrane proteins are then described.
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Affiliation(s)
- Kristaps Jaudzems
- Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280 - CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, 163 The Green, DE 19716, USA
| | - Guido Pintacuda
- Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280 - CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Hartmut Oschkinat
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. (FMP), Campus Berlin-Buch Robert-Roessle-Str. 10 13125 Berlin, Germany
| | - Anne Lesage
- Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280 - CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
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15
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Saliba E, Sesti EL, Alaniva N, Barnes AB. Pulsed Electron Decoupling and Strategies for Time Domain Dynamic Nuclear Polarization with Magic Angle Spinning. J Phys Chem Lett 2018; 9:5539-5547. [PMID: 30180584 PMCID: PMC6151657 DOI: 10.1021/acs.jpclett.8b01695] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/04/2018] [Indexed: 05/05/2023]
Abstract
Magic angle spinning (MAS) dynamic nuclear polarization (DNP) is widely used to increase nuclear magnetic resonance (NMR) signal intensity. Frequency-chirped microwaves yield superior control of electron spins and are expected to play a central role in the development of DNP MAS experiments. Time domain electron control with MAS has considerable promise to improve DNP performance at higher fields and temperatures. We have recently demonstrated that pulsed electron decoupling using frequency-chirped microwaves improves MAS DNP experiments by partially attenuating detrimental hyperfine interactions. The continued development of pulsed electron decoupling will enable a new suite of MAS DNP experiments that transfer polarization directly to observed spins. Time domain DNP transfers to nuclear spins in conjunction with pulsed electron decoupling is described as a viable avenue toward DNP-enhanced, high-resolution NMR spectroscopy over a range of temperatures from <6 to 320 K.
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Affiliation(s)
- Edward
P. Saliba
- Department of Chemistry, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
| | - Erika L. Sesti
- Department of Chemistry, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
| | - Nicholas Alaniva
- Department of Chemistry, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
| | - Alexander B. Barnes
- Department of Chemistry, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
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16
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Martin RW, Kelly JE, Kelz JI. Advances in instrumentation and methodology for solid-state NMR of biological assemblies. J Struct Biol 2018; 206:73-89. [PMID: 30205196 DOI: 10.1016/j.jsb.2018.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 07/08/2018] [Accepted: 09/06/2018] [Indexed: 01/11/2023]
Abstract
Many advances in instrumentation and methodology have furthered the use of solid-state NMR as a technique for determining the structures and studying the dynamics of molecules involved in complex biological assemblies. Solid-state NMR does not require large crystals, has no inherent size limit, and with appropriate isotopic labeling schemes, supports solving one component of a complex assembly at a time. It is complementary to cryo-EM, in that it provides local, atomic-level detail that can be modeled into larger-scale structures. This review focuses on the development of high-field MAS instrumentation and methodology; including probe design, benchmarking strategies, labeling schemes, and experiments that enable the use of quadrupolar nuclei in biomolecular NMR. Current challenges facing solid-state NMR of biological assemblies and new directions in this dynamic research area are also discussed.
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Affiliation(s)
- Rachel W Martin
- Department of Chemistry, University of California, Irvine 92697-2025, United States; Department of Molecular Biology and Biochemistry, University of California, Irvine 92697-3900, United States.
| | - John E Kelly
- Department of Chemistry, University of California, Irvine 92697-2025, United States
| | - Jessica I Kelz
- Department of Chemistry, University of California, Irvine 92697-2025, United States
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17
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Timm KN, Miller JJ, Henry JA, Tyler DJ. Cardiac applications of hyperpolarised magnetic resonance. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 106-107:66-87. [PMID: 31047602 DOI: 10.1016/j.pnmrs.2018.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/14/2018] [Accepted: 05/29/2018] [Indexed: 05/05/2023]
Abstract
Cardiovascular disease is the leading cause of death world-wide. It is increasingly recognised that cardiac pathologies show, or may even be caused by, changes in metabolism, leading to impaired cardiac energetics. The heart turns over 15 times its own weight in ATP every day and thus relies heavily on the availability of substrates and on efficient oxidation to generate this ATP. A number of old and emerging drugs that target different aspects of metabolism are showing promising results with regard to improved cardiac outcomes in patients. A non-invasive imaging technique that could assess the role of different aspects of metabolism in heart disease, as well as measure changes in cardiac energetics due to treatment, would be valuable in the routine clinical care of cardiac patients. Hyperpolarised magnetic resonance spectroscopy and imaging have revolutionised metabolic imaging, allowing real-time metabolic flux assessment in vivo for the first time. In this review we summarise metabolism in the healthy and diseased heart, give an introduction to the hyperpolarisation technique, 'dynamic nuclear polarisation' (DNP), and review the preclinical studies that have thus far explored healthy cardiac metabolism and different models of human heart disease. We furthermore show what advances have been made to translate this technique into the clinic, what technical challenges still remain and what unmet clinical needs and unexplored metabolic substrates still need to be assessed by researchers in this exciting and fast-moving field.
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Affiliation(s)
- Kerstin N Timm
- Department of Physiology, Anatomy and Genetics, University of Oxford, UK.
| | - Jack J Miller
- Department of Physiology, Anatomy and Genetics, University of Oxford, UK; Oxford Centre for Clinical Magnetic Resonance Research, John Radcliffe Hospital, Oxford, UK; Clarendon Laboratory, Department of Physics, University of Oxford, UK.
| | - John A Henry
- Department of Physiology, Anatomy and Genetics, University of Oxford, UK.
| | - Damian J Tyler
- Department of Physiology, Anatomy and Genetics, University of Oxford, UK; Oxford Centre for Clinical Magnetic Resonance Research, John Radcliffe Hospital, Oxford, UK.
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18
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Jaudzems K, Bertarello A, Chaudhari SR, Pica A, Cala-De Paepe D, Barbet-Massin E, Pell AJ, Akopjana I, Kotelovica S, Gajan D, Ouari O, Tars K, Pintacuda G, Lesage A. Dynamic Nuclear Polarization-Enhanced Biomolecular NMR Spectroscopy at High Magnetic Field with Fast Magic-Angle Spinning. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201801016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Kristaps Jaudzems
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Andrea Bertarello
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Sachin R. Chaudhari
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Andrea Pica
- Department of Chemical Sciences; University of Naples Federico II; Via Cintia I-80126 Naples Italy
| | - Diane Cala-De Paepe
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Emeline Barbet-Massin
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Andrew J. Pell
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
- Present address: Department of Materials and Environmental Chemistry; Arrhenius Laboratory; Stockholm University; Svante Arrhenius Väg 16 C SE-106 91 Stockholm Sweden
| | - Inara Akopjana
- Biomedical Research and Study Centre; Rātsupītes 1 LV1067 Riga Latvia
| | | | - David Gajan
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Olivier Ouari
- Aix-Marseille Université, CNRS, ICR UMR 7273; 13397 Marseille cedex 20 France
| | - Kaspars Tars
- Biomedical Research and Study Centre; Rātsupītes 1 LV1067 Riga Latvia
| | - Guido Pintacuda
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Anne Lesage
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
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19
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Jaudzems K, Bertarello A, Chaudhari SR, Pica A, Cala-De Paepe D, Barbet-Massin E, Pell AJ, Akopjana I, Kotelovica S, Gajan D, Ouari O, Tars K, Pintacuda G, Lesage A. Dynamic Nuclear Polarization-Enhanced Biomolecular NMR Spectroscopy at High Magnetic Field with Fast Magic-Angle Spinning. Angew Chem Int Ed Engl 2018; 57:7458-7462. [DOI: 10.1002/anie.201801016] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/06/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Kristaps Jaudzems
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Andrea Bertarello
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Sachin R. Chaudhari
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Andrea Pica
- Department of Chemical Sciences; University of Naples Federico II; Via Cintia I-80126 Naples Italy
| | - Diane Cala-De Paepe
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Emeline Barbet-Massin
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Andrew J. Pell
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
- Present address: Department of Materials and Environmental Chemistry; Arrhenius Laboratory; Stockholm University; Svante Arrhenius Väg 16 C SE-106 91 Stockholm Sweden
| | - Inara Akopjana
- Biomedical Research and Study Centre; Rātsupītes 1 LV1067 Riga Latvia
| | | | - David Gajan
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Olivier Ouari
- Aix-Marseille Université, CNRS, ICR UMR 7273; 13397 Marseille cedex 20 France
| | - Kaspars Tars
- Biomedical Research and Study Centre; Rātsupītes 1 LV1067 Riga Latvia
| | - Guido Pintacuda
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
| | - Anne Lesage
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1; Ens Lyon; Institut des Sciences Analytiques, UMR 5280; 5 rue de la Doua F-69100 VILLEURBANNE France
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20
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Scott FJ, Saliba EP, Albert BJ, Alaniva N, Sesti EL, Gao C, Golota NC, Choi EJ, Jagtap AP, Wittmann JJ, Eckardt M, Harneit W, Corzilius B, Th Sigurdsson S, Barnes AB. Frequency-agile gyrotron for electron decoupling and pulsed dynamic nuclear polarization. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 289:45-54. [PMID: 29471275 DOI: 10.1016/j.jmr.2018.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/09/2018] [Accepted: 02/11/2018] [Indexed: 05/05/2023]
Abstract
We describe a frequency-agile gyrotron which can generate frequency-chirped microwave pulses. An arbitrary waveform generator (AWG) within the NMR spectrometer controls the microwave frequency, enabling synchronized pulsed control of both electron and nuclear spins. We demonstrate that the acceleration of emitted electrons, and thus the microwave frequency, can be quickly changed by varying the anode voltage. This strategy results in much faster frequency response than can be achieved by changing the potential of the electron emitter, and does not require a custom triode electron gun. The gyrotron frequency can be swept with a rate of 20 MHz/μs over a 670 MHz bandwidth in a static magnetic field. We have already implemented time-domain electron decoupling with dynamic nuclear polarization (DNP) magic angle spinning (MAS) with this device. In this contribution, we show frequency-swept DNP enhancement profiles recorded without changing the NMR magnet or probe. The profile of endofullerenes exhibits a DNP profile with a <10 MHz linewidth, indicating that the device also has sufficient frequency stability, and therefore phase stability, to implement pulsed DNP mechanisms such as the frequency-swept solid effect. We describe schematics of the mechanical and vacuum construction of the device which includes a novel flanged sapphire window assembly. Finally, we discuss how commercially available continuous-wave gyrotrons can potentially be converted into similar frequency-agile high-power microwave sources.
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Affiliation(s)
- Faith J Scott
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Edward P Saliba
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Brice J Albert
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Nicholas Alaniva
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Erika L Sesti
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Chukun Gao
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Natalie C Golota
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Eric J Choi
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Anil P Jagtap
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - Johannes J Wittmann
- Institute for Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt am Main, Germany
| | - Michael Eckardt
- Institut für Physikalische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz, Germany; Fachbereich Physik, Universität Osnabrück, Barbarastr. 7, 49076 Osnabrück, Germany
| | - Wolfgang Harneit
- Institut für Physikalische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz, Germany; Fachbereich Physik, Universität Osnabrück, Barbarastr. 7, 49076 Osnabrück, Germany
| | - Björn Corzilius
- Institute for Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt am Main, Germany
| | - Snorri Th Sigurdsson
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - Alexander B Barnes
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA.
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21
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Nanni EA, Jawla S, Lewis SM, Shapiro MA, Temkin RJ. Photonic-band-gap gyrotron amplifier with picosecond pulses. APPLIED PHYSICS LETTERS 2017; 111:233504. [PMID: 29249833 PMCID: PMC5718917 DOI: 10.1063/1.5006348] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 11/12/2017] [Indexed: 05/05/2023]
Abstract
We report the amplification of 250 GHz pulses as short as 260 ps without observation of pulse broadening using a photonic-band-gap circuit gyrotron traveling-wave-amplifier. The gyrotron amplifier operates with a device gain of 38 dB and an instantaneous bandwidth of 8 GHz. The operational bandwidth of the amplifier can be tuned over 16 GHz by adjusting the operating voltage of the electron beam and the magnetic field. The amplifier uses a 30 cm long photonic-band-gap interaction circuit to confine the desired TE03-like operating mode while suppressing lower order modes which can result in undesired oscillations. The circuit gain is >55 dB for a beam voltage of 23 kV and a current of 700 mA. These results demonstrate the wide bandwidths and a high gain achievable with gyrotron amplifiers. The amplification of picosecond pulses of variable lengths, 260-800 ps, shows good agreement with the theory using the coupled dispersion relation and the gain-spectrum of the amplifier as measured with quasi-CW input pulses.
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Affiliation(s)
| | - Sudheer Jawla
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Mass. Ave., Cambridge, Massachusetts 02139, USA
| | - Samantha M Lewis
- Department of Nuclear Engineering, University of California Berkeley, Berkeley, California 94720, USA
| | - Michael A Shapiro
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Mass. Ave., Cambridge, Massachusetts 02139, USA
| | - Richard J Temkin
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Mass. Ave., Cambridge, Massachusetts 02139, USA
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22
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Mentink-Vigier F, Mathies G, Liu Y, Barra AL, Caporini MA, Lee D, Hediger S, G Griffin R, De Paëpe G. Efficient cross-effect dynamic nuclear polarization without depolarization in high-resolution MAS NMR. Chem Sci 2017; 8:8150-8163. [PMID: 29619170 PMCID: PMC5861987 DOI: 10.1039/c7sc02199b] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 10/01/2017] [Indexed: 11/21/2022] Open
Abstract
Dynamic nuclear polarization (DNP) has the potential to enhance the sensitivity of magic-angle spinning (MAS) NMR by many orders of magnitude and therefore to revolutionize atomic resolution structural analysis. Currently, the most widely used approach to DNP for studies of chemical, material, and biological systems involves the cross-effect (CE) mechanism, which relies on biradicals as polarizing agents. However, at high magnetic fields (≥5 T), the best biradicals used for CE MAS-DNP are still far from optimal, primarily because of the nuclear depolarization effects they induce. In the presence of bisnitroxide biradicals, magic-angle rotation results in a reverse CE that can deplete the initial proton Boltzmann polarization by more than a factor of 2. In this paper we show that these depolarization losses can be avoided by using a polarizing agent composed of a narrow-line trityl radical tethered to a broad-line TEMPO. Consequently, we show that a biocompatible trityl-nitroxide biradical, TEMTriPol-1, provides the highest MAS NMR sensitivity at ≥10 T, and its relative efficiency increases with the magnetic field strength. We use numerical simulations to explain the absence of depolarization for TEMTriPol-1 and its high efficiency, paving the way for the next generation of polarizing agents for DNP. We demonstrate the superior sensitivity enhancement using TEMTriPol-1 by recording the first solid-state 2D 13C-13C correlation spectrum at natural isotopic abundance at a magnetic field of 18.8 T.
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Affiliation(s)
| | - Guinevere Mathies
- Francis Bitter Magnet Laboratory , Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics , School of Pharmacy , Tianjin Medical University , Tianjin 300070 , China
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques Intenses - CNRS , Univ. Grenoble Alpes , F-38042 Grenoble , France
| | - Marc A Caporini
- Bruker BioSpin Corporation , 15 Fortune Drive , Billerica , MA 01821 , USA
| | - Daniel Lee
- Univ. Grenoble Alpes , CEA , CNRS , INAC-MEM , F-38000 Grenoble , France .
| | - Sabine Hediger
- Univ. Grenoble Alpes , CEA , CNRS , INAC-MEM , F-38000 Grenoble , France .
| | - Robert G Griffin
- Francis Bitter Magnet Laboratory , Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA
| | - Gaël De Paëpe
- Univ. Grenoble Alpes , CEA , CNRS , INAC-MEM , F-38000 Grenoble , France .
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23
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Lilly Thankamony AS, Wittmann JJ, Kaushik M, Corzilius B. Dynamic nuclear polarization for sensitivity enhancement in modern solid-state NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 102-103:120-195. [PMID: 29157490 DOI: 10.1016/j.pnmrs.2017.06.002] [Citation(s) in RCA: 268] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/03/2017] [Accepted: 06/08/2017] [Indexed: 05/03/2023]
Abstract
The field of dynamic nuclear polarization has undergone tremendous developments and diversification since its inception more than 6 decades ago. In this review we provide an in-depth overview of the relevant topics involved in DNP-enhanced MAS NMR spectroscopy. This includes the theoretical description of DNP mechanisms as well as of the polarization transfer pathways that can lead to a uniform or selective spreading of polarization between nuclear spins. Furthermore, we cover historical and state-of-the art aspects of dedicated instrumentation, polarizing agents, and optimization techniques for efficient MAS DNP. Finally, we present an extensive overview on applications in the fields of structural biology and materials science, which underlines that MAS DNP has moved far beyond the proof-of-concept stage and has become an important tool for research in these fields.
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Affiliation(s)
- Aany Sofia Lilly Thankamony
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Johannes J Wittmann
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Monu Kaushik
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany
| | - Björn Corzilius
- Institute of Physical and Theoretical Chemistry, Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7-9, 60438 Frankfurt, Germany.
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Jain SK, Mathies G, Griffin RG. Off-resonance NOVEL. J Chem Phys 2017; 147:164201. [PMID: 29096491 PMCID: PMC5659863 DOI: 10.1063/1.5000528] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 10/10/2017] [Indexed: 11/14/2022] Open
Abstract
Dynamic nuclear polarization (DNP) is theoretically able to enhance the signal in nuclear magnetic resonance (NMR) experiments by a factor γe/γn, where γ's are the gyromagnetic ratios of an electron and a nuclear spin. However, DNP enhancements currently achieved in high-field, high-resolution biomolecular magic-angle spinning NMR are well below this limit because the continuous-wave DNP mechanisms employed in these experiments scale as ω0-n where n ∼ 1-2. In pulsed DNP methods, such as nuclear orientation via electron spin-locking (NOVEL), the DNP efficiency is independent of the strength of the main magnetic field. Hence, these methods represent a viable alternative approach for enhancing nuclear signals. At 0.35 T, the NOVEL scheme was demonstrated to be efficient in samples doped with stable radicals, generating 1H NMR enhancements of ∼430. However, an impediment in the implementation of NOVEL at high fields is the requirement of sufficient microwave power to fulfill the on-resonance matching condition, ω0I = ω1S, where ω0I and ω1S are the nuclear Larmor and electron Rabi frequencies, respectively. Here, we exploit a generalized matching condition, which states that the effective Rabi frequency, ω1Seff, matches ω0I. By using this generalized off-resonance matching condition, we generate 1H NMR signal enhancement factors of 266 (∼70% of the on-resonance NOVEL enhancement) with ω1S/2π = 5 MHz. We investigate experimentally the conditions for optimal transfer of polarization from electrons to 1H both for the NOVEL mechanism and the solid-effect mechanism and provide a unified theoretical description for these two historically distinct forms of DNP.
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Affiliation(s)
- Sheetal K Jain
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Guinevere Mathies
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Robert G Griffin
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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25
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Albert BJ, Pahng SH, Alaniva N, Sesti EL, Rand PW, Saliba EP, Scott FJ, Choi EJ, Barnes AB. Instrumentation for cryogenic magic angle spinning dynamic nuclear polarization using 90L of liquid nitrogen per day. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 283:71-78. [PMID: 28888182 PMCID: PMC6411293 DOI: 10.1016/j.jmr.2017.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 08/25/2017] [Accepted: 08/29/2017] [Indexed: 05/05/2023]
Abstract
Cryogenic sample temperatures can enhance NMR sensitivity by extending spin relaxation times to improve dynamic nuclear polarization (DNP) and by increasing Boltzmann spin polarization. We have developed an efficient heat exchanger with a liquid nitrogen consumption rate of only 90L per day to perform magic-angle spinning (MAS) DNP experiments below 85K. In this heat exchanger implementation, cold exhaust gas from the NMR probe is returned to the outer portion of a counterflow coil within an intermediate cooling stage to improve cooling efficiency of the spinning and variable temperature gases. The heat exchange within the counterflow coil is calculated with computational fluid dynamics to optimize the heat transfer. Experimental results using the novel counterflow heat exchanger demonstrate MAS DNP signal enhancements of 328±3 at 81±2K, and 276±4 at 105±2K.
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Affiliation(s)
- Brice J Albert
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Seong Ho Pahng
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Nicholas Alaniva
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Erika L Sesti
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Peter W Rand
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Edward P Saliba
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Faith J Scott
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Eric J Choi
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Alexander B Barnes
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA.
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26
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Bernard GM, Goyal A, Miskolzie M, McKay R, Wu Q, Wasylishen RE, Michaelis VK. Methylammonium lead chloride: A sensitive sample for an accurate NMR thermometer. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 283:14-21. [PMID: 28843057 DOI: 10.1016/j.jmr.2017.08.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 07/28/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
A new solid-state nuclear magnetic resonance (NMR) thermometry sample is proposed. The 207Pb NMR chemical shift of a lead halide perovskite, methylammonium lead chloride (MAPbCl3) is very sensitive to temperature, 0.905±0.010ppmK-1. The response to temperature is linear over a wide temperature range, from its tetragonal to cubic phase transition at 178K to >410K, making it an ideal standard for temperature calibrations in this range. Because the 207Pb NMR lineshape for MAPbCl3 appears symmetric, the sample is ideal for calibration of variable temperature NMR data acquired for spinning or non-spinning samples. A frequency-ratio method is proposed for referencing 207Pb chemical shifts, based on the 1H and 13C frequencies of the methylammonium cation, which are used asan internal standard. Finally, this new NMR thermometer has been used to measure the degree of frictional heating asa function of spinning frequency for a series of MAS rotors ranging in outer diameter from 1.3 to 7.0mm. As expected, the largest diameter rotors are more susceptible to frictional heating, but lower diameter rotors are subjected to higher frictional heating temperatures as they are typically spun at much higher spinning frequencies.
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Affiliation(s)
- Guy M Bernard
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Atul Goyal
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Mark Miskolzie
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Ryan McKay
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Qichao Wu
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
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27
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Can TV, Weber RT, Walish JJ, Swager TM, Griffin RG. Frequency-Swept Integrated Solid Effect. Angew Chem Int Ed Engl 2017; 56:6744-6748. [PMID: 28497528 PMCID: PMC5546875 DOI: 10.1002/anie.201700032] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/06/2017] [Indexed: 11/12/2022]
Abstract
The efficiency of continuous wave dynamic nuclear polarization (DNP) experiments decreases at the high magnetic fields used in contemporary high-resolution NMR applications. To recover the expected signal enhancements from DNP, we explored time domain experiments such as NOVEL which matches the electron Rabi frequency to the nuclear Larmor frequency to mediate polarization transfer. However, satisfying this matching condition at high frequencies is technically demanding. As an alternative we report here frequency-swept integrated solid effect (FS-ISE) experiments that allow low power sweeps of the exciting microwave frequencies to constructively integrate the negative and positive polarizations of the solid effect, thereby producing a polarization efficiency comparable to (±10 % difference) NOVEL. Finally, the microwave frequency modulation results in field profiles that exhibit new features that we coin the "stretched" solid effect.
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Affiliation(s)
- Thach V Can
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ralph T Weber
- Bruker BioSpin Corporation, Billerica, MA, 01821, USA
| | - Joseph J Walish
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Timothy M Swager
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Robert G Griffin
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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28
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Can TV, Weber RT, Walish JJ, Swager TM, Griffin RG. Frequency-Swept Integrated Solid Effect. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201700032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Thach V. Can
- Francis Bitter Magnet Laboratory; Massachusetts Institute of Technology; Cambridge MA 02139 USA
- Department of Chemistry; Massachusetts Institute of Technology; Cambridge MA 02139 USA
| | | | - Joseph J. Walish
- Department of Chemistry; Massachusetts Institute of Technology; Cambridge MA 02139 USA
| | - Timothy M. Swager
- Department of Chemistry; Massachusetts Institute of Technology; Cambridge MA 02139 USA
| | - Robert G. Griffin
- Francis Bitter Magnet Laboratory; Massachusetts Institute of Technology; Cambridge MA 02139 USA
- Department of Chemistry; Massachusetts Institute of Technology; Cambridge MA 02139 USA
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29
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Serrao EM, Brindle KM. Dynamic nuclear polarisation: The future of imaging in oncology? Porto Biomed J 2017; 2:71-75. [PMID: 32258590 PMCID: PMC6806983 DOI: 10.1016/j.pbj.2017.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 01/02/2017] [Indexed: 12/19/2022] Open
Abstract
As clinical oncology evolves with new treatment options becoming available, there is an increasing demand on anatomic imaging for the assessment of patients at different stages. Imaging with hyperpolarized 13C-labelled cell substrates has the potential to become a powerful tool in many steps of clinical evaluation, offering a new metabolic metric and therefore a more personalised approach to treatment response. This articles explores the metabolic basis and potential for translation of hyperpolarised pyruvate as a dynamic nuclear polarisation probe in clinical oncology.
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Affiliation(s)
- Eva M Serrao
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Kevin M Brindle
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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30
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Can TV, Weber RT, Walish JJ, Swager TM, Griffin RG. Ramped-amplitude NOVEL. J Chem Phys 2017; 146:154204. [PMID: 28433011 PMCID: PMC5400743 DOI: 10.1063/1.4980155] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 04/03/2017] [Indexed: 11/14/2022] Open
Abstract
We present a pulsed dynamic nuclear polarization (DNP) study using a ramped-amplitude nuclear orientation via electron spin locking (RA-NOVEL) sequence that utilizes a fast arbitrary waveform generator (AWG) to modulate the microwave pulses together with samples doped with narrow-line radicals such as 1,3-bisdiphenylene-2-phenylallyl (BDPA), sulfonated-BDPA (SA-BDPA), and trityl-OX063. Similar to ramped-amplitude cross polarization in solid-state nuclear magnetic resonance, RA-NOVEL improves the DNP efficiency by a factor of up to 1.6 compared to constant-amplitude NOVEL (CA-NOVEL) but requires a longer mixing time. For example, at τmix = 8 μs, the DNP efficiency reaches a plateau at a ramp amplitude of ∼20 MHz for both SA-BDPA and trityl-OX063, regardless of the ramp profile (linear vs. tangent). At shorter mixing times (τmix = 0.8 μs), we found that the tangent ramp is superior to its linear counterpart and in both cases there exists an optimum ramp size and therefore ramp rate. Our results suggest that RA-NOVEL should be used instead of CA-NOVEL as long as the electronic spin lattice relaxation T1e is sufficiently long and/or the duty cycle of the microwave amplifier is not exceeded. To the best of our knowledge, this is the first example of a time domain DNP experiment that utilizes modulated microwave pulses. Our results also suggest that a precise modulation of the microwave pulses can play an important role in optimizing the efficiency of pulsed DNP experiments and an AWG is an elegant instrumental solution for this purpose.
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Affiliation(s)
- T V Can
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - R T Weber
- Bruker BioSpin Corporation, Billerica, Massachusetts 01821, USA
| | - J J Walish
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - T M Swager
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - R G Griffin
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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31
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Engin Kirimli H. Determining the interaction and characterization of asphaltene in alkylbenzene solvents using nuclear-electron double resonance. J DISPER SCI TECHNOL 2017. [DOI: 10.1080/01932691.2016.1180627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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32
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Kaushik M, Qi M, Godt A, Corzilius B. Bis-Gadolinium Complexes for Solid Effect and Cross Effect Dynamic Nuclear Polarization. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201612388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Monu Kaushik
- Goethe-Universität Frankfurt am Main; Institut für Physikalische und Theoretische Chemie; Institut für Biophysikalische Chemie und Biomolekulares Magnetresonanzzentrum (BMRZ); Max-von-Laue-Strasse 7-9 60438 Frankfurt am Main Germany
| | - Mian Qi
- Fakultät für Chemie und Centrum für Molekulare Materialien (CM 2 ); Universität Bielefeld; Universitätsstrasse 25 33615 Bielefeld Germany
| | - Adelheid Godt
- Fakultät für Chemie und Centrum für Molekulare Materialien (CM 2 ); Universität Bielefeld; Universitätsstrasse 25 33615 Bielefeld Germany
| | - Björn Corzilius
- Goethe-Universität Frankfurt am Main; Institut für Physikalische und Theoretische Chemie; Institut für Biophysikalische Chemie und Biomolekulares Magnetresonanzzentrum (BMRZ); Max-von-Laue-Strasse 7-9 60438 Frankfurt am Main Germany
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33
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Ryan H, van Bentum J, Maly T. A ferromagnetic shim insert for NMR magnets - Towards an integrated gyrotron for DNP-NMR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 277:1-7. [PMID: 28189087 PMCID: PMC5796668 DOI: 10.1016/j.jmr.2017.01.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 01/26/2017] [Accepted: 01/29/2017] [Indexed: 05/20/2023]
Abstract
In recent years high-field Dynamic Nuclear Polarization (DNP) enhanced NMR spectroscopy has gained significant interest. In high-field DNP-NMR experiments (⩾400MHz 1H NMR, ⩾9.4T) often a stand-alone gyrotron is used to generate high microwave/THz power to produce sufficiently high microwave induced B1e fields at the position of the NMR sample. These devices typically require a second, stand-alone superconducting magnet to operate. Here we present the design and realization of a ferroshim insert, to create two iso-centers inside a commercially available wide-bore NMR magnet. This work is part of a larger project to integrate a gyrotron into NMR magnets, effectively eliminating the need for a second, stand-alone superconducting magnet.
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Affiliation(s)
- Herbert Ryan
- Bridge12 Technologies, 37 Loring Drive, Framingham, MA 01702, USA
| | - Jan van Bentum
- Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Thorsten Maly
- Bridge12 Technologies, 37 Loring Drive, Framingham, MA 01702, USA
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34
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Combining DNP NMR with segmental and specific labeling to study a yeast prion protein strain that is not parallel in-register. Proc Natl Acad Sci U S A 2017; 114:3642-3647. [PMID: 28330994 DOI: 10.1073/pnas.1619051114] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The yeast prion protein Sup35NM is a self-propagating amyloid. Despite intense study, there is no consensus on the organization of monomers within Sup35NM fibrils. Some studies point to a β-helical arrangement, whereas others suggest a parallel in-register organization. Intermolecular contacts are often determined by experiments that probe long-range heteronuclear contacts for fibrils templated from a 1:1 mixture of 13C- and 15N-labeled monomers. However, for Sup35NM, like many large proteins, chemical shift degeneracy limits the usefulness of this approach. Segmental and specific isotopic labeling reduce degeneracy, but experiments to measure long-range interactions are often too insensitive. To limit degeneracy and increase experimental sensitivity, we combined specific and segmental isotopic labeling schemes with dynamic nuclear polarization (DNP) NMR. Using this combination, we examined an amyloid form of Sup35NM that does not have a parallel in-register structure. The combination of a small number of specific labels with DNP NMR enables determination of architectural information about polymeric protein systems.
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35
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Kaushik M, Qi M, Godt A, Corzilius B. Bis-Gadolinium Complexes for Solid Effect and Cross Effect Dynamic Nuclear Polarization. Angew Chem Int Ed Engl 2017; 56:4295-4299. [DOI: 10.1002/anie.201612388] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Monu Kaushik
- Goethe-Universität Frankfurt am Main; Institut für Physikalische und Theoretische Chemie; Institut für Biophysikalische Chemie und Biomolekulares Magnetresonanzzentrum (BMRZ); Max-von-Laue-Strasse 7-9 60438 Frankfurt am Main Germany
| | - Mian Qi
- Fakultät für Chemie und Centrum für Molekulare Materialien (CM 2 ); Universität Bielefeld; Universitätsstrasse 25 33615 Bielefeld Germany
| | - Adelheid Godt
- Fakultät für Chemie und Centrum für Molekulare Materialien (CM 2 ); Universität Bielefeld; Universitätsstrasse 25 33615 Bielefeld Germany
| | - Björn Corzilius
- Goethe-Universität Frankfurt am Main; Institut für Physikalische und Theoretische Chemie; Institut für Biophysikalische Chemie und Biomolekulares Magnetresonanzzentrum (BMRZ); Max-von-Laue-Strasse 7-9 60438 Frankfurt am Main Germany
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36
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Timm KN, Kennedy BWC, Brindle KM. Imaging Tumor Metabolism to Assess Disease Progression and Treatment Response. Clin Cancer Res 2016; 22:5196-5203. [PMID: 27609841 PMCID: PMC5321522 DOI: 10.1158/1078-0432.ccr-16-0159] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/09/2016] [Indexed: 12/26/2022]
Abstract
Changes in tumor metabolism may accompany disease progression and can occur following treatment, often before there are changes in tumor size. We focus here on imaging methods that can be used to image various aspects of tumor metabolism, with an emphasis on methods that can be used for tumor grading, assessing disease progression, and monitoring treatment response. Clin Cancer Res; 22(21); 5196-203. ©2016 AACR.
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Affiliation(s)
- Kerstin N Timm
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom
| | - Brett W C Kennedy
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom
| | - Kevin M Brindle
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom
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37
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Can TV, Walish JJ, Swager TM, Griffin RG. Time domain DNP with the NOVEL sequence. J Chem Phys 2016; 143:054201. [PMID: 26254646 DOI: 10.1063/1.4927087] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We present results of a pulsed dynamic nuclear polarization (DNP) study at 0.35 T (9.7 GHz/14.7 MHz for electron/(1)H Larmor frequency) using a lab frame-rotating frame cross polarization experiment that employs electron spin locking fields that match the (1)H nuclear Larmor frequency, the so called NOVEL (nuclear orientation via electron spin locking) condition. We apply the method to a series of DNP samples including a single crystal of diphenyl nitroxide (DPNO) doped benzophenone (BzP), 1,3-bisdiphenylene-2-phenylallyl (BDPA) doped polystyrene (PS), and sulfonated-BDPA (SA-BDPA) doped glycerol/water glassy matrices. The optimal Hartman-Hahn matching condition is achieved when the nutation frequency of the electron matches the Larmor frequency of the proton, ω(1S) = ω(0I), together with possible higher order matching conditions at lower efficiencies. The magnetization transfer from electron to protons occurs on the time scale of ∼100 ns, consistent with the electron-proton couplings on the order of 1-10 MHz in these samples. In a fully protonated single crystal DPNO/BzP, at 270 K, we obtained a maximum signal enhancement of ε = 165 and the corresponding gain in sensitivity of ε(T1/T(B))(1/2)=230 due to the reduction in the buildup time under DNP. In a sample of partially deuterated PS doped with BDPA, we obtained an enhancement of 323 which is a factor of ∼3.2 higher compared to the protonated version of the same sample and accounts for 49% of the theoretical limit. For the SA-BDPA doped glycerol/water glassy matrix at 80 K, the sample condition used in most applications of DNP in nuclear magnetic resonance, we also observed a significant enhancement. Our findings demonstrate that pulsed DNP via the NOVEL sequence is highly efficient and can potentially surpass continuous wave DNP mechanisms such as the solid effect and cross effect which scale unfavorably with increasing magnetic field. Furthermore, pulsed DNP is also a promising avenue for DNP at high temperature.
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Affiliation(s)
- T V Can
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J J Walish
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - T M Swager
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - R G Griffin
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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38
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Matsuki Y, Idehara T, Fukazawa J, Fujiwara T. Advanced instrumentation for DNP-enhanced MAS NMR for higher magnetic fields and lower temperatures. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:107-115. [PMID: 26920836 DOI: 10.1016/j.jmr.2016.01.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/14/2016] [Accepted: 01/19/2016] [Indexed: 05/03/2023]
Abstract
Sensitivity enhancement of MAS NMR using dynamic nuclear polarization (DNP) is gaining importance at moderate fields (B0<9T) and temperatures (T>90K) with potential applications in chemistry and material sciences. However, considering the ever-increasing size and complexity of the systems to be studied, it is crucial to establish DNP under higher field conditions, where the spectral resolution and the basic NMR sensitivity tend to improve. In this perspective, we overview our recent efforts on hardware developments, specifically targeted on improving DNP MAS NMR at high fields. It includes the development of gyrotrons that enable continuous frequency tuning and rapid frequency modulation for our 395 GHz-600 MHz and 460 GHz-700 MHz DNP NMR spectrometers. The latter 700 MHz system involves two gyrotrons and a quasi-optical transmission system that combines two independent sub-millimeter waves into a single dichromic wave. We also describe two cryogenic MAS NMR probe systems operating, respectively, at T ∼ 100K and ∼ 30K. The latter system utilizes a novel closed-loop helium recirculation mechanism, achieving cryogenic MAS without consuming any cryogen. These instruments altogether should promote high-field DNP toward more efficient, reliable and affordable technology. Some experimental DNP results obtained with these instruments are presented.
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Affiliation(s)
- Yoh Matsuki
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toshitaka Idehara
- Research Center for Development of Far-Infrared Region, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
| | - Jun Fukazawa
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toshimichi Fujiwara
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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39
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Rosay M, Blank M, Engelke F. Instrumentation for solid-state dynamic nuclear polarization with magic angle spinning NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:88-98. [PMID: 26920834 DOI: 10.1016/j.jmr.2015.12.026] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/17/2015] [Accepted: 12/18/2015] [Indexed: 05/08/2023]
Abstract
Advances in dynamic nuclear polarization (DNP) instrumentation and methodology have been key factors in the recent growth of solid-state DNP NMR applications. We review the current state of the art of solid-state DNP NMR instrumentation primarily based on available commercial platforms. We start with a general system overview, including options for microwave sources and DNP NMR probes, and then focus on specific developments for DNP at 100K with magic angle spinning (MAS). Gyrotron microwave sources, passive components to transmit microwaves, the DNP MAS probe, a cooling device for low-temperature MAS, and sample preparation procedures including radicals for DNP are considered.
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Affiliation(s)
- Melanie Rosay
- Bruker-Biospin, 15 Fortune Drive, Billerica, MA 01730, USA.
| | - Monica Blank
- Communications and Power Industries, 811 Hansen Way, Palo Alto, CA 94304, USA.
| | - Frank Engelke
- Bruker-Biospin, Silberstreifen 4, 76287 Rheinstetten, Germany.
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40
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Abstract
Continuous-wave (CW) dynamic nuclear polarization (DNP) is now established as a method of choice to enhance the sensitivity in a variety of NMR experiments. Nevertheless, there remains a need for the development of more efficient methods to transfer polarization from electrons to nuclei. Of particular interest are pulsed DNP methods because they enable a rapid and efficient polarization transfer that, in contrast with CW DNP methods, is not attenuated at high magnetic fields. Here we report nuclear spin orientation via electron spin-locking (NOVEL) experiments using the polarizing agent trityl OX063 in glycerol/water at a temperature of 80 K and a magnetic field of 0.34 T. (1)H NMR signal enhancements up to 430 are observed, and the buildup of the local polarization occurs in a few hundred nanoseconds. Thus, NOVEL can efficiently dynamically polarize (1)H atoms in a system that is of general interest to the solid-state DNP NMR community. This is a first, important step toward the general application of pulsed DNP at higher fields.
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41
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Smith AN, Long JR. Dynamic Nuclear Polarization as an Enabling Technology for Solid State Nuclear Magnetic Resonance Spectroscopy. Anal Chem 2016; 88:122-32. [PMID: 26594903 PMCID: PMC5704910 DOI: 10.1021/acs.analchem.5b04376] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Adam N Smith
- Department of Chemistry, University of Florida , 214 Leigh Hall, Gainesville, Florida 32611-7200, United States
| | - Joanna R Long
- Department of Biochemistry and Molecular Biology, University of Florida , P. O. Box 100245, Gainesville, Florida 32610-0245, United States
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42
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Perras FA, Reinig RR, Slowing II, Sadow AD, Pruski M. Effects of biradical deuteration on the performance of DNP: towards better performing polarizing agents. Phys Chem Chem Phys 2015; 18:65-9. [PMID: 26619055 DOI: 10.1039/c5cp06505d] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We study the effects of the deuteration of biradical polarizing agents on the efficiency of dynamic nuclear polarization (DNP) via the cross-effect. To this end, we synthesized a series of bTbK and TOTAPol biradicals with systematically increased deuterium substitution. The deuteration increases the radicals' relaxation time, thus contributing to a higher saturation factor and larger DNP enhancement, and reduces the pool of protons within the so-called spin diffusion barrier. Notably, we report that full or partial deuteration leads to improved DNP enhancement factors in standard samples, but also slows down the build-up of hyperpolarization. Improvements in DNP enhancements factors of up to 70% and time savings of up to 38% are obtained upon full deuteration. It is foreseen that this approach may be applied to other DNP polarizing agents thus enabling further sensitivity improvements.
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Affiliation(s)
- Frédéric A Perras
- U.S. DOE Ames Laboratory, Iowa State University, 230 Spedding Hall, Ames, IA 50011-3020, USA.
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43
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Hoff DEM, Albert BJ, Saliba EP, Scott FJ, Choi EJ, Mardini M, Barnes AB. Frequency swept microwaves for hyperfine decoupling and time domain dynamic nuclear polarization. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 72:79-89. [PMID: 26482131 PMCID: PMC4762658 DOI: 10.1016/j.ssnmr.2015.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 05/05/2023]
Abstract
Hyperfine decoupling and pulsed dynamic nuclear polarization (DNP) are promising techniques to improve high field DNP NMR. We explore experimental and theoretical considerations to implement them with magic angle spinning (MAS). Microwave field simulations using the high frequency structural simulator (HFSS) software suite are performed to characterize the inhomogeneous phase independent microwave field throughout a 198GHz MAS DNP probe. Our calculations show that a microwave power input of 17W is required to generate an average EPR nutation frequency of 0.84MHz. We also present a detailed calculation of microwave heating from the HFSS parameters and find that 7.1% of the incident microwave power contributes to dielectric sample heating. Voltage tunable gyrotron oscillators are proposed as a class of frequency agile microwave sources to generate microwave frequency sweeps required for the frequency modulated cross effect, electron spin inversions, and hyperfine decoupling. Electron spin inversions of stable organic radicals are simulated with SPINEVOLUTION using the inhomogeneous microwave fields calculated by HFSS. We calculate an electron spin inversion efficiency of 56% at a spinning frequency of 5kHz. Finally, we demonstrate gyrotron acceleration potentials required to generate swept microwave frequency profiles for the frequency modulated cross effect and electron spin inversions.
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Affiliation(s)
- Daniel E M Hoff
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Brice J Albert
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Edward P Saliba
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Faith J Scott
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Eric J Choi
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Michael Mardini
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Alexander B Barnes
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA.
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44
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Frederick KK, Michaelis VK, Corzilius B, Ong TC, Jacavone AC, Griffin RG, Lindquist S. Sensitivity-enhanced NMR reveals alterations in protein structure by cellular milieus. Cell 2015; 163:620-8. [PMID: 26456111 PMCID: PMC4621972 DOI: 10.1016/j.cell.2015.09.024] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 07/03/2015] [Accepted: 08/26/2015] [Indexed: 12/11/2022]
Abstract
Biological processes occur in complex environments containing a myriad of potential interactors. Unfortunately, limitations on the sensitivity of biophysical techniques normally restrict structural investigations to purified systems, at concentrations that are orders of magnitude above endogenous levels. Dynamic nuclear polarization (DNP) can dramatically enhance the sensitivity of nuclear magnetic resonance (NMR) spectroscopy and enable structural studies in biologically complex environments. Here, we applied DNP NMR to investigate the structure of a protein containing both an environmentally sensitive folding pathway and an intrinsically disordered region, the yeast prion protein Sup35. We added an exogenously prepared isotopically labeled protein to deuterated lysates, rendering the biological environment "invisible" and enabling highly efficient polarization transfer for DNP. In this environment, structural changes occurred in a region known to influence biological activity but intrinsically disordered in purified samples. Thus, DNP makes structural studies of proteins at endogenous levels in biological contexts possible, and such contexts can influence protein structure.
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Affiliation(s)
| | - Vladimir K Michaelis
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Björn Corzilius
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ta-Chung Ong
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Angela C Jacavone
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Robert G Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Susan Lindquist
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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45
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Wilhelm D, Purea A, Engelke F. Fluid flow dynamics in MAS systems. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 257:51-63. [PMID: 26073599 DOI: 10.1016/j.jmr.2015.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 05/15/2015] [Accepted: 05/18/2015] [Indexed: 06/04/2023]
Abstract
The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3mm-rotor diameter has been analyzed for spinning rates up to 67kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor.
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Affiliation(s)
- Dirk Wilhelm
- Zurich University of Applied Sciences, Institute of Applied Mathematics and Physics, Techikumstrasse 9, 8400 Winterthur, Switzerland.
| | - Armin Purea
- Bruker Biospin GmbH, Am Silberstreifen 4, 76287 Rheinstetten, Germany
| | - Frank Engelke
- Bruker Biospin GmbH, Am Silberstreifen 4, 76287 Rheinstetten, Germany
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46
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Mance D, Gast P, Huber M, Baldus M, Ivanov KL. The magnetic field dependence of cross-effect dynamic nuclear polarization under magic angle spinning. J Chem Phys 2015; 142:234201. [DOI: 10.1063/1.4922219] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Deni Mance
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Peter Gast
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
| | - Martina Huber
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Konstantin L. Ivanov
- International Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3a, Novosibirsk 630090, Russia and Novosibirsk State University, Pirogova 2, Novosibirsk 63009, Russia
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47
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Can TV, Ni QZ, Griffin RG. Mechanisms of dynamic nuclear polarization in insulating solids. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 253:23-35. [PMID: 25797002 PMCID: PMC4371145 DOI: 10.1016/j.jmr.2015.02.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 02/05/2015] [Accepted: 02/09/2015] [Indexed: 05/04/2023]
Abstract
Dynamic nuclear polarization (DNP) is a technique used to enhance signal intensities in NMR experiments by transferring the high polarization of electrons to their surrounding nuclei. The past decade has witnessed a renaissance in the development of DNP, especially at high magnetic fields, and its application in several areas including biophysics, chemistry, structural biology and materials science. Recent technical and theoretical advances have expanded our understanding of established experiments: for example, the cross effect DNP in samples spinning at the magic angle. Furthermore, new experiments suggest that our understanding of the Overhauser effect and its applicability to insulating solids needs to be re-examined. In this article, we summarize important results of the past few years and provide quantum mechanical explanations underlying these results. We also discuss future directions of DNP and current limitations, including the problem of resolution in protein spectra recorded at 80-100 K.
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Affiliation(s)
- T V Can
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Q Z Ni
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - R G Griffin
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
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48
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Koers EJ, van der Cruijsen EAW, Rosay M, Weingarth M, Prokofyev A, Sauvée C, Ouari O, van der Zwan J, Pongs O, Tordo P, Maas WE, Baldus M. NMR-based structural biology enhanced by dynamic nuclear polarization at high magnetic field. JOURNAL OF BIOMOLECULAR NMR 2014; 60:157-68. [PMID: 25284462 DOI: 10.1007/s10858-014-9865-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/23/2014] [Indexed: 05/04/2023]
Abstract
Dynamic nuclear polarization (DNP) has become a powerful method to enhance spectroscopic sensitivity in the context of magnetic resonance imaging and nuclear magnetic resonance spectroscopy. We show that, compared to DNP at lower field (400 MHz/263 GHz), high field DNP (800 MHz/527 GHz) can significantly enhance spectral resolution and allows exploitation of the paramagnetic relaxation properties of DNP polarizing agents as direct structural probes under magic angle spinning conditions. Applied to a membrane-embedded K(+) channel, this approach allowed us to refine the membrane-embedded channel structure and revealed conformational substates that are present during two different stages of the channel gating cycle. High-field DNP thus offers atomic insight into the role of molecular plasticity during the course of biomolecular function in a complex cellular environment.
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Affiliation(s)
- Eline J Koers
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
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49
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Slichter CP. The discovery and renaissance of dynamic nuclear polarization. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:072501. [PMID: 24994709 DOI: 10.1088/0034-4885/77/7/072501] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In 1952, Overhauser proposed a method for transferring the large electron spin polarization of conduction electrons in a metal to the metal nuclei, enhancing their polarization one thousand fold. Such an enhancement method is called dynamic nuclear polarization (DNP). The article explains his idea, describes the experiments of Carver and Slichter that confirmed his proposal, their demonstration that the method was not limited to metals, describes the nature of immediate impact on the magnetic resonance community, discusses why DNP was not broadly utilized for many years, explains in simple terms how the method works and reports on the new developments in experimental methods that have given DNP an active and exciting future.
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Affiliation(s)
- Charles P Slichter
- Department of Physics, University of Illinois, 1110 West Green Street, Urbana, IL 61801, USA
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50
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Le D, Casano G, Phan TNT, Ziarelli F, Ouari O, Aussenac F, Thureau P, Mollica G, Gigmes D, Tordo P, Viel S. Optimizing Sample Preparation Methods for Dynamic Nuclear Polarization Solid-state NMR of Synthetic Polymers. Macromolecules 2014. [DOI: 10.1021/ma500788n] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Dao Le
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Gilles Casano
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Trang N. T. Phan
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Fabio Ziarelli
- Aix Marseille Université, CNRS, Centrale Marseille, Fédération
des Sciences Chimiques de Marseille FR 1739, 13397, Marseille, France
| | - Olivier Ouari
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | | | - Pierre Thureau
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Giulia Mollica
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Didier Gigmes
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Paul Tordo
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
| | - Stéphane Viel
- Aix Marseille Université, CNRS,
ICR UMR 7273, 13397, Marseille, France
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