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Sami Jannin

Cette personne a quitté l’EPFL

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Publications associées (57)

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Challenges in preparing, preserving and detecting para-water in bulk: overcoming proton exchange and other hurdles

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Diego Carnevale, Daniele Mammoli, Nicola Salvi, Roberto Buratto, Estel Canet Martinez

Para-water is an analogue of para-hydrogen, where the two proton spins are in a quantum state that is antisymmetric under permutation, also known as singlet state. The populations of the nuclear spin states in para-water are believed to have long lifetimes ...

Royal Society of Chemistry2015

A spinning thermometer to monitor microwave heating and glass transitions in dynamic nuclear polarization

Geoffrey Bodenhausen, Sandrine Gerber, Sami Jannin, Pascal Miéville, Marc Anthony Caporini

As previously demonstrated by Thurber and Tycko, the peak position of Br-79 in potassium bromide (KBr) allows one to determine the temperature of a spinning sample. We propose to adapt the original design by using a compact KBr tablet placed at the bottom ...

Wiley-Blackwell2011

Long-Lived States of Magnetically Equivalent Spins Populated by Dissolution-DNP and Revealed by Enzymatic Reactions

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Basile Vuichoud, Daniele Mammoli, Xiao Ji

Hyperpolarization by dissolution dynamic nuclear polarization (D-DNP) offers a way of enhancing NMR signals by up to five orders of magnitude in metabolites and other small molecules. Nevertheless, the lifetime of hyperpolarization is inexorably limited, a ...

Wiley-Blackwell2014

Design and performance of a DNP prepolarizer coupled to a rodent MRI scanner

Rolf Gruetter, Arnaud Comment, Sami Jannin, Jacques Van Der Klink

For most of the last forty years, the techniques of Dynamic Nuclear Polarization (DNP) have been confined to particle-physics laboratories building polarized targets, but recently it has been shown that samples similar to a solid target can be transformed ...

2007

An apparatus for pulsed ESR and DNP experiments using optically excited triplet states down to liquid helium temperatures

Arnaud Comment, Sami Jannin, Jacques Van Der Klink, Tim Rolf Eichhorn

In standard Dynamic Nuclear Polarization (DNP) electron spins are polarized at low temperatures in a strong magnetic field and this polarization is transferred to the nuclear spins by means of a microwave field. To obtain high nuclear polarizations cryogen ...

Academic Press2013

Three-field NMR to preserve hyperpolarized proton magnetization as long-lived states in moderate magnetic fields

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet

This communication describes a three-field experiment where inequivalent scalar coupled spin pairs are hyperpolarized at 3.35 T and 1.2 K by dynamic nuclear polarization (DNP), rapidly transferred to high field (7 T) to prepare a suitable initial condition ...

Elsevier2011

Dynamic nuclear polarization of small labelled molecules in frozen water-alcohol solutions

Arnaud Comment, Sami Jannin, Jacques Van Der Klink

In recent years methods of creating 'hyperpolarized' substances have gained considerable attention in biomedical magnetic resonance and dynamic nuclear polarization (DNP) is one of the most promising, especially for imaging applications. Here we present re ...

2008

Phenylazide Hybrid-Silica - Polarization Platform for Dynamic Nuclear Polarization at Cryogenic Temperatures

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Basile Vuichoud

Hyperpolarization of NMR-active nuclei is key to gather high quality spectra of rare species and insensitive isotopes. We have recently established that silica-based materials containing regularly distributed nitroxyl radicals connected to the silica matri ...

Wiley-V C H Verlag Gmbh2017

Cross Polarization for Dissolution Dynamic Nuclear Polarization Experiments at Readily Accessible Temperatures 1.2 < T < 4.2 K

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet

Cross polarization can provide significant enhancements with respect to direct polarization of low-gamma nuclei such as C-13. Substantial gains in sample throughput (shorter polarization times) can be achieved by exploiting shorter build-up times tau(DNP)( ...

Springer Verlag2012

Dynamic nuclear polarization techniques for magnetic resonance imaging and particles targets experiments

Sami Jannin

Within a collaboration with the Sample Environment and Polarised Targets (SEPT) group at Paul Scherrer Institut (PSI), we developed two Dynamic Nuclear Polarization (DNP) machines operating at ~ 1 K. The first one is working at an electron spin resonance f ...

EPFL2009

Hybrid polarizing solids for pure hyperpolarized liquids through dissolution dynamic nuclear polarization

Geoffrey Bodenhausen, David Lyndon Emsley, Sami Jannin, Aurélien Bornet, Jonas Milani, Basile Vuichoud

Hyperpolarization of substrates for magnetic resonance spectroscopy (MRS) and imaging (MRI) by dissolution dynamic nuclear polarization (D-DNP) usually involves saturating the ESR transitions of polarizing agents (PAs; e.g., persistent radicals embedded in ...

National Academy of Sciences2014

Hyperpolarization of Deuterated Metabolites via Remote Cross-Polarization and Dissolution Dynamic Nuclear Polarization

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Basile Vuichoud

In deuterated molecules such as [1-C-13]pyruvate-d(3), the nuclear spin polarization of C-13 nuclei can be enhanced by combining Hartmann-Hahn cross-polarization (CP) at low temperatures (1.2 K) with dissolution dynamic nuclear polarization (D-DNP). The po ...

American Chemical Society2014

Producing over 100 ml of highly concentrated hyperpolarized solution by means of dissolution DNP

Arnaud Comment, Sami Jannin, Ruud van Heeswijk, Jacques Van Der Klink

New low-temperature inserts compatible with an existing hyperpolarizer were developed to dynamically polarize nuclei in large samples. The performance of the system was tested on 8 ml glassy frozen solutions containing 13C-labeled molecules and doped with ...

Academic Press Inc - Elsevier Science2008

Measuring absolute spin polarization in dissolution-DNP by Spin PolarimetrY Magnetic Resonance (SPY-MR)

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Basile Vuichoud

Dynamic nuclear polarization at 1.2 K and 6.7 T allows one to achieve spin temperatures on the order of a few millikelvin, so that the high-temperature approximation (Delta E < kT) is violated for the nuclear Zeeman interaction Delta E = gamma B(0)h/(2 pi) ...

Academic Press Inc - Elsevier Science2015

Drug Screening Boosted by Hyperpolarized Long-Lived States in NMR

Geoffrey Bodenhausen, Sandrine Gerber, Sami Jannin, Aurélien Bornet, Jonas Milani, Basile Vuichoud, Solène Marcelle Françoise Marie Passemard, Daniele Mammoli, Nicola Salvi, Roberto Buratto

Transverse and longitudinal relaxation times (T11 and T1) have been widely exploited in NMR to probe the binding of ligands and putative drugs to target proteins. We have shown recently that long-lived states (LLS) can be more sensitive to ligand binding. ...

Wiley-Blackwell2014

Filterable Agents for Hyperpolarization of Water, Metabolites, and Proteins

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Pascal Miéville, Basile Vuichoud, Florian Patrick Marie Daniel De la Barre De Nanteuil, Estel Canet Martinez, Xiao Ji

Hyperpolarization is generated by dissolution dynamic nuclear polarization (d-DNP) using a polymer-based polarizing agent dubbed FLAP (filterable labeled agents for polarization). It consists of a thermo-responsive poly(N-isopropylacrylamide), also known a ...

Wiley-V C H Verlag Gmbh2016

Structured and porous materials particularly suitable as polarizing agents in dissolution dynamic nuclear polarization

David Lyndon Emsley, Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet

The present invention concerns materials consisting in a porous and structured network, this network being at least in part formed by Si atoms, or Si atoms and metal atoms, linked to each other by oxy bridges, comprising organic molecules which include at ...

2016

Kinetics of Yttrium-Ligand Complexation Monitored Using Hyperpolarized 89Y as a Model for Gadolinium in Contrast Agents

Geoffrey Bodenhausen, Lothar Helm, Sami Jannin, Pascal Miéville

Hyperpolarization by dissolution dynamic nuclear polarization (DNP) enhances Y-89 spin magnetization by 3 to 4 orders of magnitude and provides a way to monitor yttrium-ligand complexation "on the fly" by means of Y-89 NMR. In this communication, we show a ...

American Chemical Society2010

Optimizing dissolution dynamic nuclear polarization

Sami Jannin, Aurélien Bornet

This article is a short review of some of our recent developments in dissolution dynamic nuclear polarization (d-DNP). We present the basic principles of d-DNP, and motivate our choice to step away from conventional approaches. We then introduce a modified ...

Academic Press Inc - Elsevier Science2016

Feasibility of in vivo N-15 MRS detection of hyperpolarized N-15 labeled choline in rats

Rolf Gruetter, Arnaud Comment, Cristina Ramona Cudalbu Moldovan, Sami Jannin, Ruud van Heeswijk

The increase of total choline in tumors has become an important biomarker in cancer diagnosis. Choline and choline metabolites can be measured in vivo and in vitro using multinuclear MRS. Recent in vivo C-13 MRS studies using labeled substrates enhanced vi ...

2010