Videos
Triplet Dynamic Nuclear Polarization
During the 66th session of the Global NMR Discussion Meetings held on May 2nd, 2023 via Zoom, Prof. Nobuhiro Yanai gave a talk on the topic "Triplet Dynamic Nuclear Polarization: New Polarizing Agents and Targets". The recording serves as a tutorial.
Abstract:
Triplet dynamic nuclear polarization (triplet-DNP), which utilizes the polarized electron spins of the photo-excited triplet, is an excellent method to obtain large nuclear spin polarization even under mild conditions below 1 T near room temperature. This talk will highlight the potential of triplet-DNP and the exciting new possibilities that have emerged with recent advancements in polarizing agents and targets. Specifically, I will cover the following topics:
- Mechanism of triplet-DNP as an introduction
- Expanding the targets using supramolecular polarizing agents
- Improving air stability and solubility with non-pentacene polarizing agents
- Challenging polarization transfer with the use of nanomaterials.
Nobuhiro Yanai is an Associate Professor, Department of Chemistry and Biochemistry, Kyushu University, Japan.
Website: https://sites.google.com/view/nobuhiroyanai/
Google scholar: https://scholar.google.com/citations?...
Twitter: https://twitter.com/nobuhiroyanai?lang=en
Surprising Consequences of High Electron Spin Polarization
During the 59th session of the Global NMR Discussion Meetings held on January 10th, 2023 via Zoom, Dr. Quentin Chappuis Stern gave a talk on the topic "The surprising consequences of near unity electron spin polarization". The recording serves as a tutorial.
Abstract:
The inherent low sensitivity of NMR can be overcome by hyperpolarization techniques, which increase the polarization of nuclear spins far beyond the Boltzmann equilibrium. One such method is dynamic nuclear polarization (DNP), which consists of transferring the high polarization of unpaired electron spins to surrounding nuclear spins via microwave irradiation. In the case of dissolution DNP (dDNP), the sample is hyperpolarized in the solid state at low temperature (1-2 K) and moderate magnetic field (3-7 T), where the Boltzmann polarization of electron spins approaches unity, translating into equally high nuclear polarization under DNP. In addition to yielding high nuclear polarization, the high electron polarization has other interesting consequences for NMR. Indeed, as the electron polarization tends towards unity, the electron flip-flop probability vanishes, an effect sometimes referred to as “bath quenching”. By switching on and off microwave irradiation (microwave gating), one switches on and off electron flip-flops and hence paramagnetic relaxation. This has been shown to have a dramatic effect on transverse nuclear relaxation and on nuclear spin diffusion. In this talk, I will review the basic concepts of paramagnetic relaxation and its dependence on electron polarization. I will then present experiments where we used microwave gating to perform efficient CP, to detect EPR properties indirectly via NMR properties, and finally to study nuclear spin diffusion in the vicinity of electron spins.
Speaker's biography:
2014- Undergraduate and Masters, EPFL (Switzerland). Thesis with Prof. Bodenhausen
2022- PhD, CRMN Lyon (France), with Prof. Sami Jannin
Follow Dr. Stern's work here:
Twitter: https://twitter.com/quentinchapp
Google scholar: https://scholar.google.fr/citations?u...
Long-lived states: some unexpected applications
During the 42nd session of the Global NMR Discussion Meetings held on February 8th, 2022 via Zoom, Prof. Geoffrey Bodenhausen gave a talk on the topic "Long-lived states: some unexpected applications". The recording serves as a tutorial.
Abstract: The invention of singlet states, also known as long-lived states (LLS), by Malcolm Levitt was to be followed by many further inventions by scores of creative co-workers in Southampton and Novosibirsk: the quest for molecules immersed in environments capable of supporting singlet states with very long lifetimes, magnetization-to-singlet conversion (M2S), extremely low frequency (ELF) excitation, classification of decay rates according to the eigenvalues of the Liouvillian, effects of exchange on the lifetimes of LLS, etc. Our laboratories at EPFL and ENS have focused on a few applications of long-lived states, such as the study of slow diffusion of macromolecules, long-lived states in substrates of enzymatic reactions, long-lived states in systems with many spins, long-lived population imbalances in systems containing quadrupolar nuclei, elusive long-lived states in water (“para-water”), and long-lived states in drug molecules binding to macromolecular targets.
Speaker's biography:
1996-present: Professor, Department of Chemistry, Ecole Normale Supérieure, Paris
2001-2016: Professor, Ecole Polytechnique Fédérale de Lausanne
1985-2001: Université de Lausanne
1994-1996: National High Magnetic Field Laboratory and Florida State University, Tallahassee
1980-1985: Post-doc at ETH with Richard Ernst
1977 :D. Phil. Oxford with Ray Freeman Corresponding member of the Netherlands Academy of Sciences (KNAW), Fellow of the American Physical Society, Latsis Prize of the Swiss National Science Foundation
Follow Prof. Bodenhausen's work here:
Google scholar: https://scholar.google.fr/citations?u...
Dissolution DNP-enhanced Zero- to Ultralow-Field NMR
In session 29 held on 8th June 2021, Román Picazo-Frutos gave a talk on dissolution dynamic nuclear polarization (DNP)-enhanced zero- to ultralow-Field nuclear magnetic resonance (NMR) spectroscopy, via Zoom. The video was recorded live during the presentation and serves as an educative lecture.
Bio:
2016: Bachelor's in Physics, Universitat de Valencia, Spain
2018: Master's degree in Physics, Johannes Gutenberg Universität, Germany
2019-present: PhD student, Helmholtz-Institut, Mainz, Germany (Prof. Dmitry Budker)
Román works on Zero- and Ultra-low field Nuclear Magnetic Resonance (ZULF NMR). Román is also interested in hyperpolarization, atomic physics, photonics and relaxometry in NMR.
Google scholar: https://scholar.google.com/citations?...
Budker group website: https://budker.uni-mainz.de/
ZULF blog post: getting rid of noise source in ZULF NMR : https://blog.zulf.eu/BP3.php
Abstract:
Zero- and ultra-low field NMR (ZULF-NMR) is a modality of NMR experiment that do not require strong magnets with applications ranging from molecular spectroscopy and chemical-reaction monitoring to dark-matter searches and exotic physics. However, it suffers from low sensitivity. In this work we combine dissolution Dynamic Nuclear Polarization (dDNP) to enhance biomolecules signals in a ZULF-NMR experiment. We discuss the scope of this hyperpolarization technique for ZULF NMR, such as the sample transfer and paramagnetic relaxation caused by the polarizing agent in DNP. We believe this technique can become an established choice for hyperpolarization in ZULF NMR.
Additional references:
Proton to carbon polarization transfer in NMR: https://onlinelibrary.wiley.com/doi/a...
Observing through metal containers at zero field: https://pubs.rsc.org/en/content/artic...
General Review on ZULF NMR: https://onlinelibrary.wiley.com/doi/a...
Dissolution DNP towards Clinical MRI
The 7th session of the Global NMR Discussion Meeting was held on 19th June 2020 via Zoom. Dr. Ardenkjær-Larsen gave a talk on the following topic: Dissolution DNP (Dynamic Nuclear Polarization) towards Clinical MRI (Magnetic Resonance Imaging). The video was recorded live during the presentation and serves as an educative lecture.
Prof. Ardenkjær-Larsen the head of Center for Magnetic Resonance and also the center leader for Center for Hyperpolarization in Magnetic Resonance at the Technical University of Denmark (DTU).
Follow Prof. Ardenkjær-Larsen on Twitter: @ardenkjaer
Website: cmr.healthtech.dtu.dk
Google Scholar: https://scholar.google.co.uk/citation...
Dissolution Dynamic Nuclear Polarization: Genesis and Metamorphosis
In the third session of the Global NMR Discussion Meeting held on 22nd May 2020 via Zoom, Prof. Sami Jannin from CRMN, Lyon (France) gave a talk on the following topic: Dissolution Dynamic Nuclear Polarization: Genesis and Metamorphosis. The video was recorded live during the presentation and serves as an educative lecture for those wanting to learn Dissolution Dynamic Nuclear Polarization.
Prof. Sami Jannin is a professor at Université de Lyon, the Deputy Director of Center Resonance Magnétique Nucleaire À Très Hauts Champs (Lyon, France) and the Head of the Hyperpolarized Magnetic Resonance Laboratory. Research group website: https://www.hmrlab.eu/
Follow Prof. Jannin on Twitter: @Sami_HMRlab