DNP-NMR Literature Blog

Design of Nuclear Magnetic Resonance Molecular Probes for Hyperpolarized Bioimaging

Kondo, Yohei, Hiroshi Nonaka, Yoichi Takakusagi, and Shinsuke Sando. “Design of Nuclear Magnetic Resonance Molecular Probes for Hyperpolarized Bioimaging.” Angewandte Chemie International Edition, May 6, 2020, anie.201915718.

https://doi.org/10.1002/anie.201915718

Nuclear hyperpolarization has emerged as a method to dramatically enhance the sensitivity of NMR. By applying this powerful tool, small molecules with stable isotopes have been subjected to highly sensitive biomedical molecular imaging. The recent development of molecular probes for hyperpolarized in vivo analysis has demonstrated the ability of this technique to provide unique metabolic and physiological information. This review presents a brief introduction of hyperpolarization technology, approaches to rational design of molecular probes for hyperpolarized analysis, and examples of molecules that have met with in vitro or in vivo success.

[NMR] Senior MRS Scientist position at Synex Medical, Toronto/Boston/Remote

Senior Magnetic Resonance Scientist

Apply here:https://synex.breezy.hr/p/01e875623b57-senior-magnetic-resonance-scientist

Synex Medical is developing the next generation of non-invasive health sensors to allow for continuous monitoring at the molecular level. Our technology is based on novel techniques in magnetic resonance that allow us to accurately measure critical blood-metabolites completely non-invasively and in highly miniaturized form-factors. We want people to have access to their own metabolism and to make predictive healthcare the norm.

We are an incredibly driven team that are working with the leading experts in our field. We’re looking for a person with experience in magnetic resonance spectroscopy who’s ambitious to tackle hard and exciting problems. 

As a Senior Magnetic Resonance Scientist, you will:

  • Work closely with the NMR team and leading academic collaborators to develop and optimize highly advanced pulse sequences for in vivo measurements.
  • Translate existing pulse sequences from high-field spectrometers to use on benchtop and custom systems.
  • Build and work with ultra compact, low-field (< 1 Tesla) NMR systems.
  • Work with a team of some of the leading electrical engineers, embedded firmware and FPGA designers, and machine learning & signal processing engineers to produce creative solutions to complex scientific challenges.
  • Stay up to date on state-of-the-art NMR techniques and come up with innovative ways of applying them to our technology.

We are looking for someone with:

  • 3+ years of experience working on NMR or MRI platforms.
  • A Ph.D. with an emphasis on applied Magnetic Resonance. M.Sc with significant and highly relevant experience will also be considered.
  • Pulse sequence development experience will be a significant asset.
  • Thorough understanding of magnetic resonance theory and NMR/MRI experimental techniques.
  • Experience with complex sample and/or biological MR techniques.
  • Familiarity with common NMR/MR softwares and pulse sequence programming (e.g. Topspin). Should be able to understand and translate pulse sequences from major NMR/MRI vendors.
  • An ambition and drive to tackle hard problems.

Nice to haves:

  • Experience with permanent magnet NMR, signal processing and analysis, and NMR hardware.
  • Experience with low field NMR (< 1 Tesla) and/or MRI.
  • Experience with in vivo MRS techniques.
  • Experience with modeling NMR experiments and spin dynamics using Hamiltonian and Bloch equation simulations.

Perks: 

  • Competitive salary and company ownership opportunities.
  • A diverse and accepting work atmosphere.
  • Minimum three (3) weeks of vacation entitlement for all new employees.
  • Employee training and development initiatives and support for career advancement (through financial assistance and flexible scheduling).
  • Flexibility in working schedule.

Rudraksha “Rudy” Majumdar, Ph.D.Senior NMR Scientist www.synexmedical.comC:+1 (647) 573-33962 Bloor Street E, Suite 310 Toronto, ON M4W 1A8

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[NMR] Postdoctoral Position on Biophysical NMR at Merck & Co, Inc. (US)

Yongchao SU yongchaosu@gmail.com via listes.univ-paris-diderot.fr Tue, Jan 12, 4:23 PM (19 hours ago)
to nmr

Dear NMR Colleagues,

I’d like to share a three-year-term postdoc opening at Merck & Co, Inc. in the United States. It is a great opportunity for those who would like to pursue an industrial career and utilize this powerful and lovely tool to advance biopharmaceutical characterization for drug product developments.

The proposed study is to investigate molecular mechanisms to understand (in-)stability of oligonucleotide, protein and mAb therapeutics in biological formulations. All junior researchers with solution NMR and/or solid-state NMR training are welcome to apply. Research experiences on biomacromolecules using NMR are appreciated. 

Many thanks if you could share with your group and networks. Interested candidates can forward CVs to me at yongchao.su@merck.com .

Postdoctoral Research Fellow – Biophysical NMR of Protein Therapeutics job in Rahway, New Jersey, United States of America | Research & Development jobs at Merck

Thanks,

Yongchao Su

Principal Scientist

Head of Biopharmaceutical NMR Lab (BNL)

Pharmaceutical Sciences | Preclinical Development

Merck & Co. Inc, Rahway, NJ 07065

Google Scholar | LinkedIn
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Parahydrogen‐Induced Radio Amplification by Stimulated Emission of Radiation

Joalland, Baptiste, Nuwandi M. Ariyasingha, Sören Lehmkuhl, Thomas Theis, Stephan Appelt, and Eduard Y. Chekmenev. “Parahydrogen‐Induced Radio Amplification by Stimulated Emission of Radiation.” Angewandte Chemie International Edition 59, no. 22 (May 25, 2020): 8654–60.

https://doi.org/10.1002/anie.201916597

Radio amplification by stimulated emission of radiation (RASER) was recently discovered in a low-field NMR spectrometer incorporating a highly specialized radiofrequency resonator, where a high degree of proton-spin polarization was achieved by reversible parahydrogen exchange. RASER activity, which results from the coherent coupling between the nuclear spins and the inductive detector, can overcome the limits of frequency resolution in NMR. Here we show that this phenomenon is not limited to low magnetic fields or the use of resonators with high-quality factors. We use a commercial bench-top 1.4 T NMR spectrometer in conjunction with pairwise parahydrogen addition producing protonhyperpolarized molecules in the Earth s magnetic field (ALTADENA condition) or in a high magnetic field (PASADENA condition) to induce RASER without any radio-frequency excitation pulses. The results demonstrate that RASER activity can be observed on virtually any NMR spectrometer and measures most of the important NMR parameters with high precision.

Analysis of the electronic structure of the primary electron donor of photosystem I of Spirodela oligorrhiza by photochemically induced dynamic nuclear polarization (photo-CIDNP) solid-state nuclear magnetic resonance (NMR)

Janssen, Geertje J., Patrick Eschenbach, Patrick Kurle, Bela E. Bode, Johannes Neugebauer, Huub J. M. de Groot, Jörg Matysik, and Alia Alia. “Analysis of the Electronic Structure of the Primary Electron Donor of Photosystem I of Spirodela Oligorrhiza by Photochemically Induced Dynamic Nuclear Polarization (Photo-CIDNP) Solid-State Nuclear Magnetic Resonance (NMR).” Magnetic Resonance 1, no. 2 (November 13, 2020): 261–74.

https://doi.org/10.5194/mr-1-261-2020

The electron donor in photosystem I (PSI), the chlorophyll dimer P700, is studied by photochemically induced dynamic nuclear polarization (photo-CIDNP) magic angle spinning (MAS) nuclear magnetic resonance (NMR) on selectively 13C and uniformly 15N labeled PSI core preparations (PSI-100) obtained from the aquatic plant duckweed (Spirodela oligorrhiza). Light-induced signals originate from the isotope-labeled nuclei of the cofactors involved in the spin-correlated radical pair forming upon light excitation. Signals are assigned to the two donor cofactors (Chl a and Chl a’) and the two acceptor cofactors (both Chl a). Light-induced signals originating from both donor and acceptor cofactors demonstrate that electron transfer occurs through both branches of cofactors in the pseudo-C2 symmetric reaction center (RC). The experimental results supported by quantum chemical calculations indicate that this functional symmetry occurs in PSI despite similarly sized chemical shift differences between the cofactors of PSI and the functionally asymmetric special pair donor of the bacterial RC of Rhodobacter sphaeroides. This contributes to converging evidence that local differences in time-averaged electronic ground-state properties, over the donor are of little importance for the functional symmetry breaking across photosynthetic RC species.

SLIM: A Short‐Linked, Highly Redox‐Stable Trityl Label for High‐Sensitivity In‐Cell EPR Distance Measurements

Fleck, Nico, Caspar A. Heubach, Tobias Hett, Florian R. Haege, Pawel P. Bawol, Helmut Baltruschat, and Olav Schiemann. “SLIM: A Short‐Linked, Highly Redox‐Stable Trityl Label for High‐Sensitivity In‐Cell EPR Distance Measurements.” Angewandte Chemie International Edition 59, no. 24 (June 8, 2020): 9767–72.

https://doi.org/10.1002/anie.202004452

The understanding of biomolecular function is coupled to knowledge about the structure and dynamics of these biomolecules, preferably acquired under native conditions. In this regard, pulsed dipolar EPR spectroscopy (PDS) in conjunction with site-directed spin labeling (SDSL) is an important method in the toolbox of biophysical chemistry. However, the currently available spin labels have diverse deficiencies for in cell applications, e.g. low radical stability or long bioconjugation linkers. In this work, a synthesis strategy is introduced for the derivatization of trityl radicals with a maleimide functionalized methylene group. The resulting trityl spin label SLIM yields narrow distance distributions, enables highly sensitive distance measurements down to concentrations of 90 nM and shows high stability against reduction. Using this label, the GDI domain of YopO is shown to change its conformation within eukaryotic cells.

[NMR] Postdoc position on DNP/RF instrumentation at ENS Paris #DNPNMR

Hi all,
There is a postdoc position available in Kong Ooi Tan’s team at ENS Paris starting in spring 2021. Initial contract is for one year, and renewable at the end of each contract year. The main goal of the project is to develop rf and microwave instrumentation for Dynamic Nuclear Polarization (DNP) techniques at high magnetic fields, i.e., ≥ 9.4 T/ 400 MHz/ 263 GHz. The candidate needs to build a DNP NMR probe with optimized rf & microwave delivery from the source to the sample at a cryogenic condition. The array of instruments that has to be built includes microwave waveguides, resonant cavity, and rf resonance circuitry. Hence, candidates with experience in assembling rf and microwave components is highly desirable. Besides, we will build a low-cost EPR circuitry in the same probe to allow the characterization of the DNP polarizing agents using EPR spectroscopy. Our lab houses an 800 MHz/ 527 GHz MAS-DNP spectrometer, a 600 MHz, a 400 MHz, and two dissolution-DNP polarizers (a Bruker prototype at 6.7 T/ 188 GHz and a home-built cryogen-free system at 9.4 T/ 263 GHz).
More details are available at https://euraxess.ec.europa.eu/jobs/590039Group website: http://www.paris-en-resonance.fr
Feel free to circulate the advertisement to whoever might be interested in this position.
Thank you for your time and happy holidays!
Regards,Kong

Prof. Kong Ooi Tan
Junior ProfessorLaboratoire des Biomolécules UMR 7203 
Département de Chimie
École Normale Supérieure 24 Rue Lhomond 
75231 Paris CEDEX 05
Université PSLhttp://www.paris-en-resonance.fr

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[NMR] Solid-State NMR Service Manager position at Durham University (UK)

Dear colleagues,

In preparation for the retirement of the current manager, we are looking for an experienced solid-state NMR practitioner to run the Durham Solid-State NMR Research Service (https://www.dur.ac.uk/solid.service/).

As well as supporting academic research, primarily for the Department of Chemistry, and particularly for the NMR research groups of Dr Karen Johnston and Prof. Paul Hodgkinson, the Service is essentially self-financing through commercial service work to industry and academia more widely. Maintaining and developing this business model will be key to renewal of the post beyond the initial two year appointment period.

Full details about the position and how to apply can be found here:

https://durham.taleo.net/careersection/du_ext/jobdetail.ftl?job=20000850

[Apologies for the excessive length of the HR-imposed application process – ability to identify the important material is the first selection criterion!]

The closing date is 24 Jan.

With good wishes,

Paul Hodgkinson

Karen Johnston
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Selective NMR observation of the SEI–metal interface by dynamic nuclear polarisation from lithium metal #DNPNMR

Hope, Michael A., Bernardine L. D. Rinkel, Anna B. Gunnarsdóttir, Katharina Märker, Svetlana Menkin, Subhradip Paul, Ivan V. Sergeyev, and Clare P. Grey. “Selective NMR Observation of the SEI–Metal Interface by Dynamic Nuclear Polarisation from Lithium Metal.” Nature Communications 11, no. 1 (December 2020): 2224.

https://doi.org/10.1038/s41467-020-16114-x

While lithium metal represents the ultimate high-energy-density battery anode material, its use is limited by dendrite formation and associated safety risks, motivating studies of the solid–electrolyte interphase layer that forms on the lithium, which is key in controlling lithium metal deposition. Dynamic nuclear polarisation enhanced NMR can provide important structural information; however, typical exogenous dynamic nuclear polarisation experiments, in which organic radicals are added to the sample, require cryogenic sample cooling and are not selective for the interface between the metal and the solid–electrolyte interphase. Here we instead exploit the conduction electrons of lithium metal to achieve an order of magnitude hyperpolarisation at room temperature. We enhance the 7Li, 1H and 19F NMR spectra of solid–electrolyte interphase species selectively, revealing their chemical nature and spatial distribution. These experiments pave the way for more ambitious room temperature in situ dynamic nuclear polarisation studies of batteries and the selective enhancement of metal–solid interfaces in a wider range of systems.

1

Dipolar nuclear polarization via the spin diffusion of a dipole order #DNPNMR

Furman, G.B., S.D. Goren, V.M. Meerovich, and V.L. Sokolovsky. “Dipolar Nuclear Polarization via the Spin Diffusion of a Dipole Order.” Journal of Magnetic Resonance 320 (November 2020): 106847.

https://doi.org/10.1016/j.jmr.2020.106847

We propose transfer of the paramagnetic impurity (PI) polarization to nuclei in bulk, outside the diffusion barrier, by using dipolar system of the nuclear spins. The transfer can overcome influence of the diffusion barrier and is proposed to be implemented in four stages. At the first stage, transition of the Zeeman PI order to the Zeeman order of nuclear spins inside the spin-diffusion barrier is occurred. During the second stage the Zeeman order of both the nuclear spins inside the barrier and the nuclear spins in bulk is transferred into the nuclear dipolar spin order. As a result, the nuclear dipolar spin reservoir inside the barrier acquires a lower spin temperature, and thus a gradient of the spin temperature of the nuclear dipolar spin system is created. Since the external magnetic field and the magnetic field created by PIs do not effect on the dipole-dipole interaction between the nuclear spins, the dipolar reservoir is common for all nuclear spins, both inside and outside the diffusion barrier. Restriction of the diffusion barrier is removed and the spin diffusion of the dipole energy and transfer of the spin dipolar order to bulk spins occurs without obstacles (the third stage). At the last stage, to register an NMR signal, the dipolar order of the bulk spins is transferred into the Zeeman order of these spins. Estimations show that enhancement of the polarization can reaches in the case of a 1H nuclear spin, ~220, for 13C ~850, and for 15N ~2130.

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