A5052081952- Advanced NMR Techniques and Applications
- Solid-state spectroscopy and crystallography
- Electron Spin Resonance Studies
- NMR spectroscopy and applications
- Atomic and Subatomic Physics Research
- X-ray Diffraction in Crystallography
- Antifungal resistance and susceptibility
- Polysaccharides and Plant Cell Walls
- Advanced MRI Techniques and Applications
- Magnetic and Electromagnetic Effects
- Fungal Infections and Studies
- Crystallization and Solubility Studies
- Advanced Condensed Matter Physics
- Synthesis and Properties of Aromatic Compounds
- Muon and positron interactions and applications
- Advanced Battery Materials and Technologies
- Photochemistry and Electron Transfer Studies
- Nuclear Physics and Applications
- Crystallography and Radiation Phenomena
- Inorganic Fluorides and Related Compounds
- Photosynthetic Processes and Mechanisms
- Legume Nitrogen Fixing Symbiosis
- Ga2O3 and related materials
- Algal biology and biofuel production
- Nuclear materials and radiation effects
National High Magnetic Field Laboratory
2017-2025
Florida State University
2017-2025
Centre National de la Recherche Scientifique
2011-2021
Institut Nanosciences et Cryogénie
2015-2021
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015-2021
CEA Grenoble
2015-2021
Université Grenoble Alpes
2015-2021
Tallahassee Orthopedic Clinic
2020
Weizmann Institute of Science
2012-2015
Chimie de la Matière Condensée de Paris
2010-2013
Lignin is a complex aromatic biopolymer that strengthens and waterproofs plant secondary cell walls, enabling mechanical stability in trees long-distance water transport xylem. removal key step paper production biomass conversion to biofuels, motivating efforts re-engineer lignin biosynthesis. However, the physical nature of lignin's interactions with wall polysaccharides not well understood. Here we show self-aggregates form highly hydrophobic dynamically unique nanodomains, extensive...
The high mortality of invasive fungal infections, and the limited number inefficacy antifungals necessitate development new agents with novel mechanisms targets. cell wall is a promising target as it contains polysaccharides absent in humans, however, its molecular structure remains elusive. Here we report architecture walls pathogenic fungus Aspergillus fumigatus. Solid-state NMR spectroscopy, assisted by dynamic nuclear polarization glycosyl linkage analysis, reveals that chitin...
Plant cell walls constitute the majority of lignocellulosic biomass and serve as a renewable resource biomaterials biofuel. Extensive interactions between polysaccharides aromatic polymer lignin make lignocellulose recalcitrant to enzymatic hydrolysis, but this network remains poorly understood. Here we interrogate nanoscale assembly components in plant stems using solid-state nuclear magnetic resonance dynamic polarization approaches. We show that extent glycan-aromatic association...
We report magic angle spinning, dynamic nuclear polarization (DNP) experiments at magnetic fields of 9.4 T, 14.1 and 18.8 T using the narrow line polarizing agents 1,3-bisdiphenylene-2-phenylallyl (BDPA) dispersed in polystyrene, sulfonated-BDPA (SA-BDPA) trityl OX063 glassy glycerol/water matrices. The 1H DNP enhancement field profiles BDPA radicals exhibit a significant Overhauser effect (OE) as well solid (SE) despite fact that these samples are insulating solids. In contrast, exhibits...
Over the last two decades solid state Nuclear Magnetic Resonance has witnessed a breakthrough in increasing nuclear polarization, and thus experimental sensitivity, with advent of Magic Angle Spinning Dynamic Polarization (MAS-DNP). To enhance polarization protons, exogenous nitroxide biradicals such as TOTAPOL or AMUPOL are routinely used. Their efficiency is usually assessed ratio between NMR signal intensity presence absence microwave irradiation εon/off. While delivers an enhancement...
We introduce a new family of highly efficient polarizing agents for dynamic nuclear polarization (DNP)-enhanced magnetic resonance (NMR) applications, composed asymmetric bis-nitroxides, in which piperidine-based radical and pyrrolinoxyl or proxyl are linked together. The design the AsymPol was guided by use advanced simulations that allow computation impact structure on DNP efficiency. These suggested relatively short linker with intention to generate sizable intramolecular electron dipolar...
The mixed trityl-TEMPO biradical TEMTriPol-1 provides excellent MAS NMR sensitivity with DNP while avoiding nuclear depolarization.
The resurgence of nuclear hyperpolarization brings new insights into spin diffusion processes near paramagnetic centers.
Abstract Efficiently hyperpolarizing proton‐dense molecular solids through dynamic nuclear polarization (DNP) solid‐state NMR is still an unmet challenge. Polarizing agents (PAs) developed so far do not perform well on proton‐rich systems, such as organic microcrystals and biomolecular assemblies. Herein we introduce a new PA, cAsymPol‐POK, report outstanding hyperpolarization efficiency 12.76 kDa U‐ 13 C, 15 N‐labeled LecA protein pharmaceutical drugs at high magnetic fields (up to 18.8 T)...
In magic angle spinning dynamic nuclear polarization (DNP), biradicals such as bis-nitroxides are used to hyperpolarize protons under microwave irradiation through the cross-effect mechanism. This mechanism relies on electron-electron spin interactions (dipolar coupling and exchange interaction) electron-nuclear (hyperfine coupling) surrounding biradical. hyperpolarization is then transferred bulk sample via diffusion. However, involvement of in biradical DNP process has been debate. this...
Abstract Antifungal echinocandins inhibit the biosynthesis of β−1,3-glucan, a major and essential polysaccharide component fungal cell wall. However, efficacy against pathogen Aspergillus fumigatus is limited. Here, we use solid-state nuclear magnetic resonance (ssNMR) other techniques to show that induce dynamic changes in assembly mobile rigid polymers within A. The reduction β−1,3-glucan induced by accompanied concurrent increase levels chitin, chitosan, highly polymorphic α−1,3-glucans,...
A deeper understanding of parameters affecting Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP), an emerging nuclear magnetic resonance hyperpolarization method, is crucial for the development new polarizing agents and successful implementation technique at higher fields (>10 T). Such progress currently impeded by computational limitation which prevents simulation large spin ensembles (electron as well spins) to accurately describe interplay between all multiple key play. In this...
The cooler the better. We report a strategy to push limits of solid-state NMR sensitivity far beyond its current state-of-the-art.
We have identified a hydrated bicarbonate formed by chemisorption of
Rapid progress has been witnessed in the past decade fields of covalent organic frameworks (COFs) and dynamic nuclear polarization (DNP). In this contribution, we bridge these two by constructing radical-embedded COFs as promising DNP agents. Via transfer from unpaired electrons to nuclei, realizes significant enhancement NMR signal intensities. One crucial issues is screen for suitable radicals act efficient polarizing agents, basic criteria which are homogeneous distribution fixed...
Abstract γ-Al 2 O 3 is one of the most widely used catalysts or catalyst supports in numerous industrial catalytic processes. Understanding structure essential to tuning its physicochemical property, which still remains a great challenge. We report strategy for observation and determination oxygen by using two-dimensional (2D) solid-state NMR spectroscopy at high field. 2D 17 double-quantum single-quantum homonuclear correlation experiment conducted an ultra-high magnetic field 35.2 T reveal...
Acetylation, a prevalent modification of cell-wall polymers, is tightly controlled regulatory process that orchestrates plant growth and environmental adaptation. However, due to limited characterization the enzymes involved, it unclear how plants establish dynamically regulate acetylation pattern in response requirements. In this study, we identified rice (
Multidimensional solid-state nuclear magnetic resonance (ssNMR) spectroscopy has emerged as an indispensable technique for resolving polymer structure and intermolecular packing in primary secondary plant cell walls. Isotope (