Session WOA. There are 5 abstracts in this session.

Session: Hyperpolarization, time: 08:30-8:55
Continuous-flow DNP polarizer for in-vivo MRI applications at 1.5 T
Vasyl Denysenkov1; Maxim Terekhov2; Richard Maeder1; Sebastian Fischer1; Stefan Zangos1; Thomas Vogl1; Thomas Prisner1
1Goethe-University Frankfurt, Frankfurt Am Main, Germany; 2University Würzburg, Würzburg, Germany
Here we describe a hyperpolarization approach for in-vivo magnetic resonance imaging at 1.5 T. Water proton enhancements of more than 20 were reached with a resonator inside the bore of the imager. Hyperpolarization is achieved by liquid water flowing continuously through the resonator filled with nitroxide radicals attached to silica gel. With an flow rate of up to 1.5 ml/min localized DNP MR angiography applications on small animals can be performed. The hyperpolarized liquid is injected with a quartz capillary directly into the blood vessels of the animal. The signal-to-noise improvement of this method will be demonstrated on two- and three-dimensional phantoms of blood vessels. Additionally our first ex-vivo and in-vivo DNP enhanced images will be shown.

Session: Hyperpolarization, time: 08:55-9:20
Nanoscale NMR and dynamic nuclear spin polarization enabled by NV centers in diamond
Fedor Jelezko
Ulm University, Ulm, Germany
This presentation is focused on applications of color centers in diamond for nanoscale nuclear magnetic resonance and dynamic nuclear spin hyperpolarization. Owing to their unique optical and spin properties nitrogen-vacancy (NV) color centers can be employed as nanoscale magnetic field sensors including application related to sensing of signals associated with external nuclear spins. We will show how coherent control techniques including entanglement-based protocols allow to increase the sensitivity and spectral resolution of NV based sensors. Applications of NV centers for hyperpolarization of nuclear spins will also be discussed.

Session: Hyperpolarization, time: 09:20-9:35
UTOPIA: A New Time-Optimized Pulsed DNP sequence
Kong Ooi Tan1; Chen Yang1; Guinevere Mathies2; Robert Griffin1
1Massachusetts Institute of Technology, Cambridge, MA; 2University of Konstanz, Konstanz, Germany
Pulsed DNP techniques offer a field-independent approach to efficiently accomplish electron-nuclear polarization transfer. However, they often require large Rabi frequencies and therefore high-power microwave irradiation, i.e. the NOVEL experiment where the matching condition is ω0I= ω1S. Inspired by the recoupling experiments in magic-angle spinning (MAS) NMR such as RFDR, we propose a new low-power DNP sequence that utilizes strategically gated microwave pulses. It therefore Utilizes Time-Optimized Pulses for Intensity Amplification and is referred to as UTOPIA. A maximum enhancement of ~ 200 with multiple resonance conditions spanning across 4ω0I was observed at 0.35 T using only ω1S⁄(2π) = 4 MHz. The pulse sequence was analysed using Floquet theory and the theoretical predictions agree well with numerical simulations.

Session: Hyperpolarization, time: 09:35-9:50
In-cell Dynamic Nuclear Polarization Using Trimodal Polarizing Agents
Brice Albert; Erika Sesti; Edward Saliba; Faith Scott; Nicholas Alaniva; Chukun Gao; Alexander Barnes
Washington University in St. Louis, St. Louis, MO
The implementation of dynamic nuclear polarization to solid-state NMR experiments provides an exquisite method for determining structural details of biomolecules within intact human cells. The complexity of cellular environments exhibit many obstacles including reduced concentration of target nuclei. To date, strategies constructed for in-cell NMR typically involve overexpression of target protein or a variety of several exogenous introduction techniques to cells. To combat the dilute and complex environment within intact human cells, we implement a class of trimodal polarizing agents for dynamic nuclear polarization. The novel polarizing agents consist of a nitroxide biradical, a cell targeting peptide linker, and a fluorophore for optical detection. This new class of polarizing agents provides robust dynamic nuclear polarization enhancements on HEK293F cells.

Session: Hyperpolarization, time: 9:50-10:05
Hyperpolarized Exchange Spectroscopy for Protein NMR
Dennis Kurzbach1; Pavel Kaderavek1; Fabien Ferrage1; Or Szekely2; Greg L. Olsen2; Lucio Frydman2; Borja Mateos3; Robert Konrat3; Geoffrey Bodenhausen1
1Ecole Normale Superieure, Paris, France; 2Weizmann Institute, Rehovot, Israel; 3University Vienna, Vienna, Austria
To rapidly map surface-active patches of proteins at residue-resolution, we show how selective hyperpolarization of solvent-exposed surface residues of the intrinsically disordered protein (IDP) osteopontin and the globular protein ubiquitin (Ubq) can be achieved by means of dissolution dynamic nuclear polarization (D-DNP). A hyperpolarized proton reservoir in the form of HDO is mixed with a protein solution and the solvent-exposed residues exchange with hyperpolarized HDO. While for OPN signal enhancements can be found along the entire primary sequence due to its disordered nature, we find that for the globular Ubq, residues buried in secondary structure elements remain unaffected. Additionally, we demonstrate that direct detection of 13C in enriched proteins can be combined with our method enabling hyperpolarized 13C-15N correlation spectroscopy.