Publications associées à Forcing the "lazy" protons to work

Magic Angle Spinning Solid-State 13C Photochemically Induced Dynamic Nuclear Polarization by a Synthetic Donor-Chromophore-Acceptor System at 9.4 T

David Lyndon Emsley, Michael Allan Hope, Máté Visegrádi, Federico De Biasi

Solid-state photochemically induced dynamic nuclear polarization (photo-CIDNP) is a nuclear magnetic resonance spectroscopy technique in which nuclear spin hyperpolarization is generated upon optical irradiation of an appropriate donor-acceptor system. Unt ...

Amer Chemical Soc2024

Magnetic structure and magnetoelectric properties of the spin-flop phase in LiFePO4

Sofie Janas, Ellen Fogh, Paola Caterina Forino

We investigate the magnetic structure and magnetoelectric(ME) effect in the high -field phase of the antiferromagnet LiFePO 4 above the critical field of 31 T. A neutron diffraction study in pulsed magnetic fields reveals the propagation vector to be q = 0 ...

Amer Physical Soc2024

High brightness neutron source optimized for very high pulsed magnetic field experiments

Mina Akhyani

Conducting neutron scattering experiments in the presence of high pulsed magnetic fields, namely above 40 T, provides valuable information about the magnetic structures of materials. However, these experiments are challenging and time-consuming because the ...

EPFL2024

Optimal sensitivity for 1H detected relayed DNP of organic solids at fast MAS

David Lyndon Emsley, Pierrick Berruyer, Saumya Badoni

Dynamic nuclear polarization (DNP) combined with high magnetic fields and fast magic angle spinning (MAS) has opened up a new avenue for the application of exceptionally sensitive 1H NMR detection schemes to study protonated solids. Recently, it has been s ...

Academic Press Inc - Elsevier Science2024

129Xe Dynamic Nuclear Polarization Demystified: The Influence of the Glassing Matrix on the Radical Properties

Rolf Gruetter, Jean-Noël Hyacinthe, Andrea Capozzi, Thanh Phong Kevin Lê, Emma Linnea Wiström

129Xe dissolution dynamic nuclear polarization (DNP) is a controversial topic. The gold standard technique for hyperpolarized xenon magnetic resonance imaging (MRI) is spin exchange optical pumping, which received FDA approval in 2022. Nevertheless, the ve ...

2024

Magnetism of Single Surface Adsorbed Atoms Studied with Radio-Frequency STM

Clément Marie Soulard

This thesis investigates the magnetic properties of single atoms and molecules adsorbed on thin magnesium oxide decoupling layers, grown on a silver single crystal. To address these systems experimentally, we use a low temperature scanning tunneling micros ...

EPFL2024

NMR Crystallography in the Big Data Era: New Methods and Applications Powered by Machine Learning

Manuel Cordova

Structure determination of materials is key to understanding their physical properties. While single-crystal X-ray diffraction is the gold standard for structures displaying long-range order, many materials of interest are polycrystalline and/or disordered ...

EPFL2023

Harmonization of multi-scanner in vivo magnetic resonance spectroscopy: ENIGMA consortium task group considerations

Cristina Ramona Cudalbu

Magnetic resonance spectroscopy is a powerful, non-invasive, quantitative imaging technique that allows for the measurement of brain metabolites that has demonstrated utility in diagnosing and characterizing a broad range of neurological diseases. Its impa ...

FRONTIERS MEDIA SA2023

Robust gamma-aminobutyric acid and energy metabolism measurements by proton and phosphorus magnetic resonance spectroscopy and fingerprinting

Songi Lim

Magnetic resonance spectroscopy (MRS) is the only technique that can detect endogenous metabolites directly and non-invasively in vivo. It allows to identify different metabolites and analyze the dynamic neurochemical processes in the brain, skeletal muscl ...

EPFL2023

Two-dimensional Pure Isotropic Proton Solid State NMR

Manuel Cordova, David Lyndon Emsley, Pinelopi Moutzouri, Bruno Simões de Almeida, Daria Torodii

One key bottleneck of solid-state NMR spectroscopy is that H-1 NMR spectra of organic solids are often very broad due to the presence of a strong network of dipolar couplings. We have recently suggested a new approach to tackle this problem. More specifica ...

Wiley-VCH Verlag GmbH2023

Influence of DNP Polarizing Agents on Biochemical Processes: TEMPOL in Transient Ischemic Stroke

Lara Buscemi Estefanell, Mor-Miri Mishkovsky, Mario Gaetano Lepore, Jean-Noël Hyacinthe, Thanh Phong Kevin Lê

Hyperpolarization of 13C by dissolution dynamic nuclear polarization (dDNP) boosts the sensitivity of magnetic resonance spectroscopy (MRS), making possible the monitoring in vivo and in real time of the biochemical reactions of exogenously infused 13C-lab ...

2023

Magnetic structure of the two-dimensional XY antiferromagnet Sr2CoSi2O7 studied using single-crystal neutron diffraction

Bálint Náfrádi

We report a combined polarized and unpolarized neutron diffraction study on a multiferroic Sr2CoSi2O7 (SCSO) single crystal below and above the antiferromagnetic ordering temperature TN = 6.5 K. Unpolarized neutron diffraction measurements at 15 K confirm ...

AMER PHYSICAL SOC2023

Towards optical MAS magnetic resonance using optical traps

Giovanni Boero, Jens Anders, Nergiz Sahin Solmaz, Reza Farsi

Higher magic angle spinning (MAS) frequencies than currently available are desirable to improve spectral resolution in NMR and EPR systems. While conventional strategies employ pneumatic spinning limited by fluid dynamics, this paper demonstrates the devel ...

Elsevier2023

Deuterated TEKPol Biradicals and the Spin-Diffusion Barrier in MAS DNP

Dominik Józef Kubicki, David Lyndon Emsley, Yu Rao, Amrit Venkatesh, Federico De Biasi

The sensitivity of NMR spectroscopy is considerably enhanced by dynamic nuclear polarization (DNP). In DNP polarization is transferred from unpaired electrons of a polarizing agent to nearby proton spins. In solids, this transfer is followed by the transpo ...

Wiley-VCH Verlag GmbH2023

Hierarchy of the Components in Spray-Dried, Protein-Excipient Particles Using DNP-Enhanced NMR Spectroscopy

David Lyndon Emsley, Baptiste Busi, Pierrick Berruyer, Andrea Bertarello

Protein-based drugs are becoming increasingly important, but there are challenges associated with their formulation (for example, formulating stable inhalable aerosols while maintaining the proper long-term stability of the protein). Determining the morpho ...

Amer Chemical Soc2023

Development of strategies to improve 1H resolution in NMR of solids at 100 kHz magic-angle spinning

Bruno Simões de Almeida

In solid-state NMR, homonuclear dipolar couplings contribute greatly to the broadening of 1H spectral line shapes. Even at the fastest magic-angle spinning rates (MAS) available today [100-150kHz], the linewidths still extend over several hundred Hertz, li ...

EPFL2023

Barriers to resolution in 1H NMR of rotating solids

David Lyndon Emsley, Pinelopi Moutzouri, Bruno Simões de Almeida, Daria Torodii

The role of 1H solid-state NMR in structure elucidation of solids is becoming more preponderant, particularly as faster magic-angle spinning rates (MAS) become available which improve 1H detected assignment strategies. However, current 1H spectral resoluti ...

Academic Press Inc - Elsevier Science2023

Dynamic Nuclear Polarization of Inorganic Halide Perovskites

Dominik Józef Kubicki, David Lyndon Emsley, Gabriele Stevanato, Aditya Mishra, Michael Allan Hope

The intrinsic low sensitivity of nuclear magnetic resonance (NMR) experiments limits their utility for structure determination of materials. Dynamic nuclear polarization (DNP) under magic angle spinning (MAS) has shown tremendous potential to overcome this ...

2023

Single Chip Dynamic Nuclear Polarization Microsystems

Nergiz Sahin Solmaz

Nuclear magnetic resonance (NMR) methods are powerful tools employed in many fields, including physics, chemistry, material science, biology, and medicine. The use of NMR methodologies in an even wider range of applications is often hindered by the relativ ...

EPFL2023

Dynamic nuclear polarisation of 1H in Gd-doped In(OH)3

David Lyndon Emsley, Michael Allan Hope, Amrit Venkatesh, Yuxuan Zhang

Dynamic nuclear polarisation (DNP) of solids doped with high-spin metal ions, such as Gd3+, is a useful strategy to enhance the nuclear magnetic resonance (NMR) sensitivity for these samples. Spin diffusion can relay polarisation throughout a sample, which ...

Academic Press Inc - Elsevier Science2023