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Sami Jannin

Cette personne a quitté l’EPFL

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Publications associées (57)

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Method for nmr spectrometry or mri measurement using dissolution dynamic nuclear polarization (dnp) with scavenging of free radicals

Geoffrey Bodenhausen, Sami Jannin, Pascal Miéville

PROBLEM TO BE SOLVED: To provide a method for extending longitudinal relaxation time and transverse relaxation time in nuclear magnetic resonance (NMR), while removing free radicals from hyperpolarized solution. SOLUTION: A method for preparing samples for ...

2011

Ultrahigh-Resolution Magnetic Resonance in Inhomogeneous Magnetic Fields: Two-Dimensional Long-Lived-Coherence Correlation Spectroscopy

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Riddhiman Sarkar, Srinivas Chinthalapalli

A half-century quest for improving resolution in Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) has enabled the study of molecular structures, biological interactions, and fine details of anatomy. This progress largely relied on the ...

2012

Magnetotransport properties depending on the nanostructure of Fe3O4 nanowires

Jean-Philippe Ansermet, Sami Jannin, Jean-Pierre Abid, Santiago Serrano Guisan

We have studied the magnetic behaviour of Fe3O4 nanowires (NWs) with two different diameter ranges, above 150 nm and below 60 nm, made by electrodeposition techniques into a polymeric template. The nanowires were characterized using various techniques, in ...

2006

Methods for nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) measurements using long-lived states

Geoffrey Bodenhausen, Arnaud Comment, Sami Jannin, Riddhiman Sarkar, Paul Romeo Vasos

A method for nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) measurements, includes creation of enhanced polarization of nuclei of a first kind within a sample in a magnetic field at cryogenic temperatures and transfer of the polarized ...

2013

Dynamic Nuclear Polarization by Thermal Mixing Under Partial Saturation

Arnaud Comment, Sami Jannin

We describe a low-temperature thermodynamic model for dynamic nuclear polarization (DNP) via continuous-wave partial saturation of electron spin resonance (ESR) lines that are both homogeneously and inhomogeneously broadened. It is a variant of a reasoning ...

Springer Vienna2012

Transportable long-lived hyperpolarized samples

Geoffrey Bodenhausen, David Lyndon Emsley, Sami Jannin

A method for the preparation of a hyperpolarized solution of molecules comprises the steps: 1) suspending or coating of a micro-particulate matrix, which is comprising or consisting of the molecules, with a glass-forming solution or suspension comprising a ...

2016

Hyperpolarization of nitrogen-15 nuclei by cross polarization and dissolution dynamic nuclear polarization

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

Dynamic Nuclear Polarization (DNP) is often achieved by the direct transfer of polarization from electrons to nuclei such as C-13, induced by microwave saturation of the wings of narrow EPR lines of radicals like trityl. In the indirect approach on the oth ...

Amer Inst Physics2017

Hyperpolarized Water to Study Protein-Ligand Interactions

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

The affinity between a chosen target protein and small molecules is a key aspect of drug discovery. Screening by popular NMR methods such as Water-LOGSY suffers from low sensitivity and from false positives caused by aggregated or denatured proteins. This ...

2015

Method and device for rapid dnp

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet

A method for producing hyperpolarized sample material for use in magnetic resonance investigations, with a) preparing a target material, containing high gamma nuclei with a short T1, - a polarizing agent with a broad EPR line, and low gamma nuclei with a l ...

2013

Hyperpolarized Lithium-6 as a Sensor of Nanomolar Contrast Agents

Rolf Gruetter, Arnaud Comment, Cristina Ramona Cudalbu Moldovan, Sami Jannin, Chiara Perazzolo, Jacques Van Der Klink, Ruud van Heeswijk

Lithium is widely used in psychotherapy. The Li-6 isotope has a long intrinsic longitudinal relaxation time T-1 on the order of minutes, making it an ideal candidate for hyperpolarization experiments. In the present study we demonstrated that lithium-6 can ...

Wiley-Blackwell2009

Scavenging Free Radicals To Preserve Enhancement and Extend Relaxation Times in NMR using Dynamic Nuclear Polarization

Rolf Gruetter, Geoffrey Bodenhausen, Arnaud Comment, Sandrine Gerber, Mor-Miri Mishkovsky, Sami Jannin, Pascal Miéville, Riddhiman Sarkar, Paul Romeo Vasos, Puneet Ahuja

Vitamin C for longer lifetimes: N-oxide radicals that are widely used for dynamic nuclear polarization can be reduced by scavengers such as sodium ascorbate (vitamin C) during the dissolution process, thus diminishing losses of polarization during the tran ...

Wiley-Blackwell2010

Method for hyperpolarization transfer in the liquid state

Geoffrey Bodenhausen, Sami Jannin

A method for producing a hyperpolarized sample for use in a magnetic resonance investigation, with the following steps: a) providing a solid sample (50), containing long T1 nuclei and short T1 nuclei in the same molecules (51) b) hyperpolarizing the short ...

2014

Hyperpolarizing Gases via Dynamic Nuclear Polarization and Sublimation

Rolf Gruetter, Geoffrey Bodenhausen, Jean-Philippe Ansermet, Arnaud Comment, François Lazeyras, Sami Jannin, Pascal Miéville, Riddhiman Sarkar, Paul Romeo Vasos, Jean-Noël Hyacinthe, Puneet Ahuja

A high throughput method was designed to produce hyperpolarized gases by combining lowtemperature dynamic nuclear polarization with a sublimation procedure. It is illustrated by applications to 129Xe nuclear magnetic resonance in xenon gas, leading to a si ...

American Physical Society2010

Proton NMR of15N-choline metabolites enhanced by dynamic nuclear polarization

Rolf Gruetter, Geoffrey Bodenhausen, Arnaud Comment, Sami Jannin, Riddhiman Sarkar, Paul Romeo Vasos

(Figure Presented) Chemical shifts of protons can report on metabolic transformations such as the conversion of choline to phosphocholine. To follow such processes in vivo, magnetization can be enhanced by dynamic nuclear polarization (DNP). We have hyperp ...

2009

Principles of operation of a DNP prepolarizer coupled to a rodent MRI scanner

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

A dynamic nuclear polarization prepolarizer was developed and coupled to a 9.4 T rodent magnetic resonance imaging scanner in order to perform in vivo hyperpolarization experiments. In the present paper, emphasis is put on methods and hardware performance ...

2008

Homonuclear decoupling for spectral simplification of carbon-13 enriched molecules in solution-state NMR enhanced by dissolution DNP

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Diego Carnevale, Srinivas Chinthalapalli

Complex overlapping multiplets due to scalar couplings (n)J(C-13, C-13) in fully C-13-enriched molecules can be simplified by polychromatic irradiation of selected spins. The signal intensities of the remaining non-irradiated signals are proportional to th ...

Royal Society of Chemistry2016

Spin Noise Detection of Nuclear Hyperpolarization at 1.2K

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

We report proton spin noise spectra of a hyperpolarized solid sample of commonly used DNP (dynamic nuclear polarization) juice containing TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidine N-oxide) and irradiated by a microwave field at a temperature of 1.2K ...

Wiley-Blackwell2015

Hyperpolarized para-Ethanol

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

We show that an imbalance between the populations of singlet (S) and triplet (T) states in pairs of magnetically equivalent spins can be generated by dissolution dynamic nudear polarization: In partly deuterated ethanol ((CD3CH2OD)-C-13), this T/S imbalanc ...

Amer Chemical Soc2015

Cross polarization from H-1 to quadrupolar Li-6 nuclei for dissolution DNP

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Basile Vuichoud, Angel Joaquin Perez Linde

Cross polarization from protons to quadrupolar Li-6 nuclei is combined with dynamic nuclear polarization of protons at 1.2 K and 6.7 T using TEMPOL as a polarizing agent followed by rapid dissolution. Compared to direct Li-6 DNP without cross-polarization, ...

Royal Society of Chemistry2014

A 140 GHz prepolarizer for dissolution dynamic nuclear polarization

Arnaud Comment, Sami Jannin, Jacques Van Der Klink

Apart from their very classical use to build polarized targets for particle physics, the methods of dynamic nuclear polarization (DNP) have more recently found application for sensitivity enhancement in high-resolution NMR, both in the solid and in the liq ...

2008