Videos
Room Temperature DNP via P1 Centers in Diamond
During the 58th session of the Global NMR Discussion Meetings held on December 14th, 2022 via Zoom, Prof. Chandrasekhar Ramanathan from Dartmouth College, USA , gave a talk on the topic "Room Temperature DNP via substitutional-nitrogen (P1) centers in diamond". The recording serves as a tutorial.
Abstract:
Electron spins in diamond have long coherence and relaxation times at room temperature, making them an exciting platform for EPR and DNP experiments under ambient conditions. In this talk I will describe our recent W-band DNP experiments using the substitutional nitrogen (or P1) defect to hyperpolarize the 13C spins in both single crystal and diamond powders. The DNP spectra measured in these samples show signatures of multiple mechanisms including the solid effect, the cross effect, the truncated cross effect and the Overhauser effect. I will discuss how variations in the microscopic environments of the spins could lead to these observations.
Follow Prof. Ramanathan's work here:
Twitter: https://twitter.com/sekharspins
Google scholar: https://scholar.google.com/citations?...
Website: https://sites.dartmouth.edu/quantum-s...
NMR Studies of Gases Adsorbed in Materials and of CO2 Capture
During the 56th session of the Global NMR Discussion Meetings held on November 15th, 2022 via Zoom, Dr. Alexander Forse from University of Cambridge, gave a talk on the topic "A guide to NMR studies of gases adsorbed in materials, with examples on carbon dioxide capture". The recording serves as a tutorial.
Abstract:
In this zoominar I will introduce methods for carrying out NMR spectroscopy experiments on gas adsorption in porous materials. I will introduce the main approaches that are used for these experiments in the literature, and will give examples from our own research on carbon dioxide capture in metal-organic frameworks. Examples will include solid-state NMR studies of carbon dioxide capture in amine-functionalized MOFs, as well as pulsed-field gradient NMR measurements of anisotropic gas diffusion.
Speaker's biography:
2012-2015: PhD in Chemistry, University of Cambridge, UK (Prof. Grey)
2016-2019: Postdoctoral Fellow, UC Berkeley, USA (Prof. Reimer & Prof. Long)
2019-present: Assistant Professor, University of Cambridge, UK
Follow Dr. Forse's work here:
Twitter: https://twitter.com/alexforse1?lang=en
Google scholar: https://scholar.google.com/citations?...
Website: https://www.ch.cam.ac.uk/group/forse/
Paramagnetic effects in NMR: From PRE to metal ions DNP
During the 52nd session of the Global NMR Discussion Meetings held on October 4th, 2022 via Zoom, Dr. Daniel Jardon Alvarez from Weizmann Institute of Science gave a talk on the topic "Paramagnetic effects in NMR: From PRE to metal ions based DNP ". The recording serves as a tutorial.
Abstract:
DNP enhancements are distance independent as long as the nuclear relaxation is governed by paramagnetic relaxation enhancement (PRE) from the polarizing agents. This enables large and homogeneous enhancements in the bulk of inorganic materials upon doping with paramagnetic metal ions. In this talk I will present the basics of PRE and solid effect DNP and, from there, justify the initial statement.
Speaker's biography:
2006-2012: BSc, MSc - Ludwig-Maximilians University, Germany
2012-2016: PhD - University of São Paulo, Brazil
2016-2019: Postdoc - Ohio State University, USA
2019-2021: Postdoc - Weizmann Institute, Israel
2021-present: Senior Intern - Weizmann Institute, Israel
Follow Dr. Jardon Alvarez's work here:
Google scholar: https://scholar.google.com/citations?...
Twitter: @dani_jardon
Review on DNP from metal ion dopants: https://www.sciencedirect.com/science...
1H Detection, MAS & High Fields for Membrane Proteins
During the 49th session of the Global NMR Discussion Meetings held on June 14, 2022 via Zoom, Dr. Loren Andreas from Max Planck Institute for Multidisciplinary Sciences gave a talk on the topic "Proton Detection, Magic-Angle Spinning and High Magnetic Fields for Membrane Protein Structural ". The recording serves as a tutorial.
Abstract:
I will present several topics, starting with the practical aspects of setting up proton-detection measurements with 1.3 mm and 0.7 mm rotors capable of 60 and greater than 100 kHz spinning. From there, I will highlight some of our recent results including detection of bound water, hydrogen bonding interaction, as well as new developments in pulse sequences aimed at global structure determination. I may also briefly mention some DNP results.
Speaker's Biography:
2016-Present: Professor, Group Leader, MPI Göttingen, Germany
2014-2016: Postdoc ENS, Lyon, France
2014: Ph.D. MIT, Boston, USA
Website: https://www.mpinat.mpg.de/andreas
Google scholar: https://scholar.google.com/citations?...
Structure and Dynamics of Viruses by MAS NMR
During the 48th session of the Global NMR Discussion Meetings held on May 17, 2022 via Zoom, Gal Porat-Dahlerbruch from the University of Delaware gave a talk on the topic "Structure and Dynamics of Viruses by MAS NMR". The recording serves as a tutorial.
Abstract:
Magic angle spinning (MAS) NMR has been widely used to characterize the structure and dynamics of viruses at all levels of organization. In this talk, I will cover the basics of MAS NMR spectroscopy with specific emphasis on experiments designed to study viruses, discuss the advantages and complementarity of MAS NMR with respect to other structural biology techniques, and present examples of unique insights gained into HIV-1, Influenza A, Hepatitis B, and other viruses.
Read their recent review here:
Gal Porat-Dahlerbruch, Amir Goldbourt, Tatyana Polenova (2021) Virus Structures and Dynamics by Magic-Angle-Spinning NMR. Annual Review in Virology. 8(1):219-237. DOI: 10.1146/annurev-virology-011921-064653.
Speaker's biography:
2015-2018: BS Chemistry, Tel Aviv University, Israel
2018-2019: Graduate Research Assistant, Tel Aviv University, Israel (Prof. Amir Goldbourt)
2019-Present: Ph.D. Candidate, University of Delaware, USA (Prof. Tatyana Polenova)
Twitter: @MagicAngleGal
Polenova laboratory website: https://sites.udel.edu/polenova-group/
Heteronuclear Spin Decoupling in Static & Rotating Samples
During the 45th session of the Global NMR Discussion Meetings held on March 22nd, 2022 via Zoom, Prof. Matthias Ernst from ETH Zürich gave a talk on the topic "Heteronuclear Spin Decoupling in Static and Rotating Samples". The recording serves as a tutorial.
Abstract: I will discuss the fundamentals of heteronuclear decoupling with an emphasis on the differences between static and rotating samples. The talk will highlight the importance of the interaction-frame transformation in both cases and the new aspects that come up in rotating solids. In the end, I will give qualitative recommendations which sequences to use.
Speaker's biography:
1993: Ph.D, ETH Zürich (with Richard Ernst)
1994-1996: Postdoc, UC Berkeley (with Alex Pines)
1996-1998: Scientist, University of Nijmegen
1998-2011: Senior Scientist and Professor, ETH Zürich
Social Media:
Twitter: @maer
Website: https://www.nmr.ethz.ch/~maer/
Google Scholar: https://scholar.google.com/citations?...
Paramagnetic NMR: Motion, Migration, Charge Compensation in a Na+ Battery
During the 44th session of the Global NMR Discussion Meetings held on March 8th, 2022 via Zoom, Euan Bassey from Prof. Clare Grey's research group at the University of Cambridge gave a talk on the topic below. The recording serves as a tutorial.
Topic: Motion, Migration and Charge Compensation in a Na+ Ion Battery Cathode: Tales from the Paramagnetic NMR Storybook
Abstract: Sodium-ion batteries (NIBs) are a more sustainable and significantly cheaper energy storage alternative to lithium-ion batteries (LIBs) and as such are poised to play a vital role in future grid-based energy storage. To date, the capacities and rate capabilities of NIBs—limited by the cathode—are too low for many real-world applications, and the sources of NIB degradation during charge and discharge have not received the attention that LIBs have. If we are to address the energy storage problem and improve the electrochemical performance of NIB cathodes, we must understand the sources of energy losses of this poor rate behaviour in terms of the changes to the chemical structure of the cathode during charge and discharge.
Solid-state NMR (ss-NMR) is ideally suited to studying such structural changes; variable-temperature 23Na ss-NMR is invaluable in assessing the extent of Na+ ion mobility (and hence the charge-discharge rates possible in NIB cathodes), whilst 17O NMR provides a local handle on the charge compensation scheme. Amongst the families of NIB cathode materials, layered NIB cathodes are particularly attractive, owing to their high Na+ mobility and good gravimetric capacities.
In this presentation, we provide an overview of paramagnetic NMR, the effect of motion on NMR spectra and the assignment of highly paramagnetic NMR spectra. We introduce Na0.67[Mg0.28Mn0.72]O2, a high-capacity, high-rate Na+-ion cathode and go on to report the changes in Na+ ion dynamics during its first charge-discharge cycle. Using a combination of variable temperature 23Na NMR and ab initio calculations of the NMR shifts and energy barriers, we assess the mobility of Na+ ions in the structure and hopping routes of these ions. For the first time, we elucidate the superstructure of P2-Na0.67[Mg0.28Mn0.72]O2 through powder synchrotron X-ray diffraction, powder neutron diffraction and pair distribution function analysis. We examine the structural changes in this material using 25Mg and 17O NMR and use these to develop a mechanism for charge compensation.
Speaker's biography: Euan completed his BA(Cantab) and MSci in Natural Sciences at the University of Cambridge. Having fallen in love with magnetic resonance techniques and solid-state chemistry, he is currently pursuing a PhD in Chemistry, supervised by Prof. Clare Grey. Now in his fourth year, he wishes to enthuse and inspire others to use magnetic resonance techniques to understand novel systems.
Twitter: @EuanBassey
Solid-State NMR and DNP of Cellular Carbohydrates
During the 43rd session of the Global NMR Discussion Meetings held on February 22nd, 2022 via Zoom, Prof. Tuo Wang gave a talk on the topic "Cellular Carbohydrates: Limitations and Opportunities from Solid-State Nuclear Magnetic Resonance (NMR) and Dynamic Nuclear Polarization (DNP)". The recording serves as a tutorial.
Abstract: Solid-State NMR has demonstrated its unique capability of characterizing the highly polymorphic structure of carbohydrate polymers in living cells or intact tissues. Here we will present the recent applications to plant, fungi, and microalgal systems and discuss the new opportunities enabled by ultrahigh-field magnets and DNP.
Website: https://www.chemistry.msu.edu/faculty-research/faculty-members/wang-tuo.aspx
Google Scholar: https://scholar.google.com/citations?...
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...
From genome to NMR spectrum
During the 41st session of the Global NMR Discussion Meetings on Zoom held on 25th January 2022, Prof. Rachel W. Martin, University of California, Irvine, USA, gave a talk on the topic "From genome to NMR spectrum".
The slides in the talk can be downloaded here: https://drive.google.com/file/d/1OPde...
Abstract: As structural biologists, we spend much of our time preparing samples for biomolecular NMR and collecting and analyzing the data. These experimental efforts are very time- and resource-intensive, suggesting that we should pay closer attention to systematically choosing targets for investigation. The advent of inexpensive nucleic acid sequencing technology has led to the rapid proliferation of genome and transcriptome data. Thus, tens of thousands of unique and potentially valuable enzymes have been “discovered” in principle, but in reality are languishing uncharacterized in databases. Furthermore, in many enzyme discovery studies, researchers choose proteins for investigation based on factors such as expression level in the host organism, which may not reflect suitability for the desired chemical application. In this talk, I will discuss our recent efforts toward developing a workflow for efficient target selection using bioinformatics and in silico methodology. Finally, I will present molecular modeling and experimental results, including NMR spectra, for Droserasin 1, a novel antimicrobial peptide we discovered from the genome of the carnivorous plant Drosera capensis.
Prof. Martin's Biography:
2002: PhD, Yale University, USA (with Prof. Kurt W. Zilm)
2002-2005: Postdoc, University of California, Berkeley (with Prof. Alex Pines)
2005-present: Professor, Department of Chemistry and Biochemistry, University of California, Irvine
Follow Prof. Rachel W. Martin and her work on social media:
Twitter: @rachelwmartin
Website: https://probemonkey.com/
Free online resources (sequence level):
• GenBank (repository of annotated DNA sequences): https://www.ncbi.nlm.nih.gov/genbank/
• BLAST (find similar nucleic acid/protein sequences to a given sequence): https://blast.ncbi.nlm.nih.gov/Blast.cgi
• Expasy translate tool (translate nucleic acid to protein): https://web.expasy.org/translate/
• Clustal Omega (align multiple sequences, can use nucleic acid or protein): https://www.ebi.ac.uk/Tools/msa/clust...
• UniProt (find what has been published for your protein): https://www.uniprot.org/
• SignalP (predict signal sequences / targeting sequences) https://services.healthtech.dtu.dk/se...
• Scampi (predict whether your protein is a membrane protein, if yes, predict topology): https://scampi.cbr.su.se/pred/help/ Free online resources (structure level):
• Rosetta, iTasser, AlphaFold (predict protein structures from amino acid sequence) https://www.rosettacommons.org/software https://zhanggroup.org/I-TASSER/ https://alphafold.ebi.ac.uk/ https://colab.research.google.com/git...
• Modeller (Make homology models if you have the structure of a similar protein) https://salilab.org/modeller/
• Protein Data Bank (find solved structures of biological macromolecules) https://www.rcsb.org/ (North America) https://www.ebi.ac.uk/pdbe/node/1 (Europe)
What goes on inside the nucleus?
During the 39th session of the Global NMR Discussion Meetings held on November 23rd, 2021 via Zoom, Prof. Ilya Kuprov gave a talk on "What goes on inside the nucleus: origins of nuclear magnetogyric ratio and quadrupole moment". The recording serves as a tutorial.
Prof. Kuprov is a world renowned magnetic resonance spectroscopy and imaging specialist with a particular focus on large-scale computer simulation of magnetic processes in chemical and biological systems; this includes quantum optimal control and machine learning methods.
2005: DPhil, Chemistry, University of Oxford (with Prof. Peter Hore)
2005-2010: Fellow by Examination, Magdalen College, Oxford
2007-2009: Lecturer in Chemistry, University of Durham
2009-2011: EPSRC Early Career Fellow, University of Oxford
2011-present: Associate Professor of Chemical Physics at the University of Southampton
2018-present: Associate Editor, Science Advances.
Website: https://spindynamics.org
Google Scholar: https://scholar.google.com/citations?...
Time-resolved solid-state NMR: Overview, Application in Biophysics
During the 38th session of the Global NMR Discussion Meetings on Zoom, Dr. Blake Wilson, National Institute of Health (NIH) Bethesda, gave a tutorial on "Time-resolved solid-state nuclear magnetic resonance (NMR) spectroscopy: an overview, with applications to biophysical systems".
Bio of Dr. Blake Wilson:
2013: B.S. Physics, Massachusetts Institute of Technology (Prob. Bob Griffin)
2013 - 2019: PhD, University of California, Santa Barbara (Prof. Mark Sherwin and Prof. Songi Han)
2019 - Present: Postdoctoral fellow, NIH Bethesda (Dr. Rob Tycko)
Follow Dr. Wilson and his work:
Twitter: https://twitter.com/blkwiln
Google scholar: https://scholar.google.com/citations?...
Abstract: I will give an overview of time-resolved solid-state NMR techniques, and how they can be used to study structural conversion processes in biophysical systems. A variety of methods, including rapid pH jumps, rapid temperature jumps, and rapid mixing of different species, can be used to initiate biophysical processes, which can subsequently be probed with millisecond time resolution by sudden freezing followed by interrogation with solid-state NMR. I will discuss how dynamic nuclear polarization (DNP) has been shown to dramatically improve the sensitivity of time-resolved NMR techniques, with the aim of capturing structural information from sparsely populated intermediate states.
Dual NMR-EPR Detection in an Ultra Low Temperature DNP Spectrometer
During the 37th session of the Global NMR Discussion Meetings on Zoom, Kan Tagami, University of California, Santa Barbara (UCSB), gave a talk on the instrumentation aspects of a dynamic nuclear polarization spectrometer with dual nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) detection at ultra-low temperatures.
Speaker's biography:
2012 - 2016: B.S., Chemistry, College of William and Mary, USA.
2016 - present: Graduate Student Researcher, Chemistry, University of California - Santa Barbara, USA (Advisor: Prof. Songi Han)
Kan's research interest is in the spin physics and instrumentation of dynamic nuclear polarization (DNP) in solid state NMR. His goal is to improve the efficiency of solid state DNP under MAS through development of both EPR and NMR instruments, as well as use a wide variety of existing magnetic resonance techniques to characterize and exploit the underlying mechanisms of DNP. Currently, his focus is on development of a low temperature (30K), high field (7T) pulsed EPR/DNP spectrometer with magic angle spinning capabilities.
For more information, see the Han Lab website: https://han.chem.ucsb.edu
Characterization of Metal Halide Perovskites using Solid-State NMR
During the 36th session of the Global NMR Discussion Meetings on Zoom, Dr. Dominik Kubicki, University of Warwick, gave a talk on the characterization of metal halide perovskites using solid-state nuclear magnetic resonance (NMR).
Abstract: Determining the structure-property relationships at multiple length scales is one of the key tenets of rational design of new materials. I will use the example of metal halide perovskites to discuss how we can determine the atomic-level structure of solids in an element-specific manner using solid-state NMR. The range of problems includes quantifying dopant incorporation, phase segregation, halide mixing, decomposition pathways, passivation mechanisms, short-range and long-range dynamics. I will focus on the experimental challenges and discuss practical aspects of recording solid-state NMR data on this class of materials.
Bio: Dominik J. Kubicki is an assistant professor in the Department of Physics at the University of Warwick. He graduated from the Warsaw University of Technology and completed his PhD in solid-state NMR with Lyndon Emsley at EPFL (Switzerland) in 2018. He then worked in the group of Michael Grätzel and subsequently held a Marie Curie-Skłodowska Fellowship at the University of Cambridge working with Sam Stranks and Clare Grey. His research focuses on new materials for sustainable optoelectronic technologies.
Website: https://kubickilab.wordpress.com/
Google scholar: https://scholar.google.ch/citations?u...
Twitter: @DominikJKubicki
NMR Hardware
In Session 34 of the Global NMR Discussion Meetings, Dr. Mark Conradi gave a talk on NMR hardware.
Abstract: Many NMR spectroscopists are uncomfortable with hardware issues. This discussion will cover debugging techniques, so that malfunctions can be narrowed to particular components of the spectrometer. The testing of probes will be covered, as well as the basics of building special purpose probes. While you may not want to build your own 1.3 mm MAS probe, a probe for high-T, high-P, or in situ examination of batteries may be of interest.
Download Dr. Conradi's slides here: https://docs.google.com/presentation/... S
peaker's biography: Prof. Mark Conradi received his PhD in Physics under R.E. Norberg at Washington University in Saint Louis MO. He did a postdoctoral stint at Oak Ridge where he learned about free radicals and ESR. An assistant/ associate professorship followed at College of William and Mary in Virginia. He was a professor at Washington University for 29 years, moving five years ago to ABQMR, a small NMR contract research firm in New Mexico. Conradi's research themes included motions in molecular solids and metal-hydrogen systems and later the imaging of human lungs with hyperpolarized helium-3. Throughout, he has been interested in NMR hardware issues and techniques, such as NMR in diamond-anvil high-pressure cells and NMR in coin-cell batteries.
Google scholar: https://scholar.google.com/citations?...
Practicalities of SPINACH - a tutorial lecture
In Session 33 of the Global NMR Discussion Meetings, Prof. Ilya Kuprov gave a second talk on performing nuclear magnetic resonance (NMR) simulations using the SPINACH program, with an emphasis on practical aspects.
Watch Part 1 here: https://youtu.be/3fnRgGCKnLU
Download related resources from Prof. Kuprov: https://www.dropbox.com/sh/55kn4enfve...
Website and SPINACH download: https://spindynamics.org
Google Scholar: https://scholar.google.com/citations?...
Prof. Kuprov is a world renowned magnetic resonance spectroscopy and imaging specialist with a particular focus on large-scale computer simulation of magnetic processes in chemical and biological systems; this includes quantum optimal control and machine learning methods.
Bio:
2005: DPhil, Chemistry, University of Oxford (with Prof. Peter Hore)
2005-2010: Fellow by Examination, Magdalen College, Oxford 2
007-2009: Lecturer in Chemistry, University of Durham
2009-2011: EPSRC Early Career Fellow, University of Oxford
2011-present: Associate Professor of Chemical Physics at the University of Southampton
2018-present: Associate Editor, Science Advances.
Brief Principles of Symmetry-Based Recoupling in Solid-State NMR
In session 28 held on 25th May 2021, Prof. Malcolm Levitt gave a talk on the principles of symmetry-based recoupling in solid-state nuclear magnetic resonance (NMR) spectroscopy, via Zoom. The video was recorded live during the presentation and serves as an educative lecture.
Prof. Levitt obtained his PhD from Oxford University in 1981, under the supervision of Prof. Ray Freeman. He performed postdoctoral research with Profs. Shimon Vega in Israel and Richard Ernst at the ETH in Zürich (who received the Nobel Prize in Chemistry in 1991). He was then on the research staff at the Francis Bitter Magnet Laboratory at MIT, Boston, USA, for 4 years. He moved back to England as a Royal Society Research Fellow at the Centre for Superconductivity in Cambridge, before becoming a lecturer at the University of Stockholm, Sweden, where he was made a full professor in 1997. He moved back to England to take up a Professorship in Physical Chemistry at the University of Southampton in April 2001.
Website: https://www.southampton.ac.uk/chemist...
Google scholar: https://scholar.google.co.uk/citation...
Abstract:
- high-resolution solid-state NMR requires removal of anisotropic spin interactions; useful information is conveyed by anisotropic spin interactions; having the cake while eating it.
- rotational symmetries of the spin interactions; space, spin and field signatures
- magic-angle spinning and spatial averaging
- multiple-pulse NMR and spin averaging
- combined spin/spatial/time symmetries
- symmetry-based selection rules and space/spin selection diagrams
- C-sequences
- R-sequences
- some examples
Some references:
https://doi.org/10.1002/9780470034590...
https://doi.org/10.1021/ja052306h
https://doi.org/10.1016/S0009-2614(00)00340-7
https://doi.org/10.1016/0009-2614(95)00741-L
These articles can be downloaded from Dropbox: https://www.dropbox.com/sh/lxlw381wa7...
Proton detection solid-state NMR of exotic & unreceptive nuclei
In session 27 held on 11th May 2021, Dr. Amrit Venkatesh gave a talk on "Proton detection solid-state nuclear magnetic resonance (NMR) of exotic & unreceptive nuclei", via Zoom. The video was recorded live during the presentation and serves as an educative lecture.
Bio: Dr. Amrit Venkatesh received his MSc in Chemistry from the Sri Sathya Sai Institute of Higher Learning, India in 2013. Amrit worked as a research fellow at the M.S. University of Baroda for two years where he gained experience in coordination chemistry and provided solution NMR support. Following a brief internship at the NMR center at IISc Bangalore with Dr. Raghothama, Amrit moved to Iowa State University, USA where he completed his PhD under the guidance of Dr. Aaron Rossini in 2020. Amrit is currently a Marie-Curie postdoctoral fellow in Prof. Lyndon Emsley’s group at EPFL, Switzerland.
Follow Amrit: Twitter: https://twitter.com/amrit_venkatesh
Google Scholar: https://scholar.google.com/citations?...
Abstract: NMR is a powerful atomic-level characterization technique but it suffers from an intrinsically poor sensitivity. Fast magic angle spinning and 1H detection in solids improve NMR sensitivity, but these are mainly applied to common spin-1/2 isotopes such as 13C, 15N, 29Si and 31P. Whereas, over 75% of the periodic table consists of unreceptive nuclei that are under-studied using NMR due to the lack of sensitive approaches. In this contribution 1H detection methods for low-gyromagnetic ratio nuclei, half-integer quadrupolar nuclei and high-Z spin-1/2 nuclei with high chemical shift anisotropy will be discussed. Practical considerations and some recent advances will be highlighted.
For detailed information, please refer to these articles:
Low-gyromagnetic ratio nuclei:
https://pubs.acs.org/doi/abs/10.1021/...
https://www.sciencedirect.com/science...
Half-integer quadrupolar nuclei:
https://www.sciencedirect.com/science...
https://pubs.rsc.org/hy/content/artic...
Spin-1/2 nuclei with high chemical shift anisotropy:
https://www.sciencedirect.com/science...
Optimal control and its application in solid-state NMR
In session 26 held on 27th April 2021, Dr. Jan Blahut gave a talk on "Optimal control and its application in solid-state Nuclear Magnetic Resonance (NMR) spectroscopy", via Zoom. The video was recorded live during the presentation and serves as an educative lecture.
Optimal-NMR webpage: https://optimal-nmr.net
Bio:
Dr. Jan Blahut
2008-2013 M.S. in Organic Chemistry, Charles University in Prague
2013-2018 Ph.D. in Inorganic Chemistry, group of prof. P. Hermann, Charles University in Prague
2018-2020 Postdoctoral position in the group of prof. G. Pintacuda, High-filed NMR centre Lyon
2020-present: Postdoctoral position in the group of Dr. Zdenek Tosner, Charles University in Prague
Publons profile: https://publons.com/researcher/216308...
Abstract: Optimal control has its origins in economy and engineering as a mathematical tool to maximize profit or minimize disposed energy. Magnetic resonance is well suited for optimal-control application to design new pulse sequences with improved properties. We will focus on application in solid-state NMR, where the combination of sample spinning, powder averaging, dense network of involved interactions and RF field inhomogeneity render analytical approaches based on Average Hamiltonian Theory unfeasible. Despite the complexity of the problem, the practical application of optimal control based techniques is straightforward. It this tutorial we will also demonstrate how they can be implemented to your work-flow in a simple copy-paste manner, replacing traditional recoupling techniques.
Statistical Learning of NMR tensors
Session 22 held virtually via zoom on 16th February 2021 featured Dr. Deepansh Srivastava, postdoc in Prof. Philip Grandinetti's research group at Ohio State University, U.S.A. Dr. Srivastava gave a talk on "Statistical Learning of Nuclear Magnetic Resonance (NMR) tensors from 2D Isotropic/Anisotropic Correlation NMR Spectra". The video was recorded live during the presentation and serves as an educative lecture.
Follow Dr. Srivastava:
Website: https://deepanshs.github.io/home/
Google scholar: https://scholar.google.com/citations?...
Short abstract: The talk features a direct inversion of 2D isotropic/anisotropic correlation ss-NMR spectra to 3D NMR tensor parameter distribution. The problem, regularized with TSVD and smooth-LASSO methods, promote stability, sparsity, and smoothness in the solution. An application of this method on spectra of non-crystalline material will be shown.
Abstract: Many linear inversion problems involving Fredholm integrals of the first kind are frequently encountered in the field of magnetic resonance. One important application is the direct inversion of a solid-state NMR spectrum containing multiple overlapping anisotropic sub-spectra to obtain a distribution of the tensor parameters. Because of the ill-conditioned nature of this inverse problem, we investigate the use of the truncated singular value decomposition (TSVD) and smooth least absolute shrinkage and selection operator (S-LASSO) based regularization method, which (a) stabilizes the solution and (b) promotes sparsity and smoothness in the solution. We also propose an unambiguous representation for the anisotropy parameters using a piecewise polar coordinate system to minimize rank deficiency in the inversion kernel. To obtain the optimum tensor parameter distribution, we implement the k-fold cross-validation, a statistical learning method, to determine the hyperparameters of the regularized inverse problem. In this talk, I'll show the details of the linear-inversion method along with numerous illustrative applications on purely anisotropic NMR spectra, both synthetic as well as experimental two-dimensional spectra correlating the isotropic and anisotropic frequencies.