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Publications associées (28)

Impact of chlorination and ozonation of dissolved organic matter on its photo-induced production of long-lived photooxidants and excited triplet states

Silvio Canonica, Urs von Gunten, Stephanie Christa Remke, Joanna Maria Houska

Recent studies suggested that long-lived photooxidants (LLPO), which are reactive intermediates formed during irradiation of dissolved organic matter (DOM), may consist of phenoxyl radicals derived from phenolic moieties of the DOM. Besides the well-studie ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Stimulation and homogenization of the protoporphyrin IX endogenous production by photobiomodulation to increase the potency of photodynamic therapy

Georges Wagnières, Emmanuel Louis Arthur Gerelli, Jaroslava Joniová, Cyrus Kazemiraad

Protoporphyrin IX (PpIX) is produced in the mitochondria and used as fluorescent contrast agent or photosensitizer after exogenous 5-aminolevulinic acid (ALA) delivery in cancer photodynamic detection and therapy (PDT). Although routinely used in the clini ...

ELSEVIER SCIENCE SA2021

A general framework for non-exponential delayed fluorescence and phosphorescence decay analysis, illustrated on Protoporphyrin IX

Georges Wagnières, Aurelien Stephen Arnaud Gregor, Emmanuel Louis Arthur Gerelli, Jaroslava Joniová

Delayed fluorescence (DF) is a long-lived luminescence process used in a variety of applications ranging from oxygen sensing in biological tissues to organic Light Emitting Diodes. In common cases, DF results from the deexcitation of the first excited trip ...

2020

Catechin reduces phototoxic effects induced by protoporphyrin IX-based photodynamic therapy in the chick embryo chorioallantoic membrane

Georges Wagnières, Jaroslava Joniová

Significance: Side effects of many cancer treatments are associated with the production of reactive oxygen species (ROS) in normal tissues. This explains why patients treated by photodynamic therapy (PDT) often suffer from skin photosensitization, whereas ...

SPIE Society of Photo-optical Instrumentation Engineers2020

Photoprotective effect of catechin during ALA-PDT

Georges Wagnières, Jaroslava Joniová

The production of reactive oxygen species (ROS) in normal tissues is associated with side effects of many cancer treatments. This is, in particular, the case for the skin photosensitization experienced by certain patients subjected to PDT based on a system ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Laser flash photolysis study of the photoinduced oxidation of 4-(dimethylamino)benzonitrile (DMABN)

Silvio Canonica, Frank Jonathan Leresche, Urs von Gunten

Aromatic amines are aquatic contaminants for which phototransformation in surface waters can be induced by excited triplet states of dissolved organic matter ((DOM)-D-3*). The first reaction step is assumed to consist of a one-electron oxidation process of ...

ROYAL SOC CHEMISTRY2019

Photophysical Heavy-Atom Effect in Iodinated Metallocorroles: Spin-Orbit Coupling and Density of States

Majed Chergui, Marine Eva Fedora Bouduban, Enrico Pomarico

Excited-state dynamics and electronic structures of Al and Ga corrole complexes were studied as a function of the number of beta-pyrrole iodine substituents. Using spectrally broad-band femtosecond-resolved fluorescence upconversion, we determined the kine ...

AMER CHEMICAL SOC2018

Efficient intersystem crossing in 2-aminopurine riboside probed by femtosecond time-resolved transient vibrational absorption spectroscopy

Rebecca Ann Ingle, Hugo Jean Baptiste Marroux

The photophysical dynamics of 2-aminopurine riboside (2APr) in CHCl3 have been studied following excitation at (pump) = 310 nm by means of femtosecond transient vibrational absorption spectroscopy (TVAS) aided by quantum chemical density functional theory ...

ROYAL SOC CHEMISTRY2018

In vivo measurement of the tissue oxygenation by time-resolved luminescence spectroscopy of protoporphyrin IX: Strategies to minimize artefacts associated with photoproducts

Georges Wagnières, Veronika Huntosova, Emmanuel Louis Arthur Gerelli

The determination of the oxygen partial pressure (pO(2)) in real time in living biological tissues is of high interest for numerous therapeutics, including photodynamic therapy (PDT) and radiotherapy. The minimally invasive and real-time measurement of the ...

Spie-Int Soc Optical Engineering2017

Review of the role played by the photosensitizer's photobleaching during photodynamic therapy

Georges Wagnières, Matthieu Philippe Emmanuel Zellweger

Photodynamic therapy (PDT) is based on the combined administration of photosensitizing drugs and light to treat a variety of malignant, pre-malignant and also non-malignant diseases. The reactive species resulting from the excitation of the photosensitizer ...

Natl Inst Optoelectronics2016

Intra-Arterial Drug and Light Delivery for Photodynamic Therapy Using Visudyne (R): Implication for Atherosclerotic Plaque Treatment

Hubert van den Bergh, Georges Wagnières, Matthieu Philippe Emmanuel Zellweger, Manish Jain

Photodynamic therapy (PDT), which is based on the activation of photosensitizers with light, can be used to reduce plaque burden. We hypothesized that intra-arterial photosensitizer administration and photo-activation will lead to high and rapid accumulati ...

2016

Stabilization of the chiral phase of theSU(6m)Heisenberg model on the honeycomb lattice withmparticles per site formlarger than 1

Frédéric Mila, Jérôme Dufour

Low-dimensional quantum magnets at finite temperatures present a complex interplay of quantum and thermal fluctuation effects in a restricted phase space. While some information about dynamical response functions is available from theoretical studies of th ...

2016

Multi-triplet bound states and finite-temperature dynamics in highly frustrated quantum spin ladders

Frédéric Mila, Bruce Normand

2016

Photosensitizing and Inhibitory Effects of Ozonated Dissolved Organic Matter on Triplet-Induced Contaminant Transformation

Silvio Canonica, Urs von Gunten

Dissolved organic matter (DOM) is both a promoter and an inhibitor of triplet-induced organic contaminant oxidation. This dual role was systematically investigated through photochemical experiments with three types of DOM of terrestrial and aquatic origins ...

American Chemical Society2015

2D Fourier Transform Spectroscopy Setup and Ultrafast Dynamics of Porphyrins

Andre Al Haddad

The first section of the thesis discusses the development and implementation of a two dimensional Fourier transform spectroscopy setup, that permits the recording of electronic 2D spectra in the visible regime. A hollow core fiber was used to generate broa ...

EPFL2015

Proton polarization above 70% by DNP using photo-excited triplet states, a first step towards a broadband neutron spin filter

Tim Rolf Eichhorn

The use of polarized protons as neutron spin filter is an attractive alternative to the well established neutron polarization techniques, as the large, spin-clepenclent neutron scattering cross-section for protons is useful up to the sub-MeV region. Employ ...

Elsevier2014

Correlation between Protoporphyrin IX Fluorescence Intensity, Photobleaching, Pain and Clinical Outcome of Actinic Keratosis Treated by Photodynamic Therapy

Hubert van den Bergh, Georges Wagnières, Matthieu Philippe Emmanuel Zellweger, Filippo Piffaretti, Jérôme Barge

Background: Photodynamic therapy (PDT) with Metvix® is a good therapeutic option to treat actinic keratosis, but it presents drawbacks (pain, lesion recurrences, heterogeneous outcome), emphasizing the possible need to individualize treatment. Objective: W ...

Karger2013

Carbon nanotubes quench singlet oxygen generated by photosynthetic reaction centers

László Forró, Arnaud Magrez, Klara Hernadi, Endre Horvath, Krisztina Nagy

Photosensitizers may convert molecular oxygen into reactive oxygen species (ROS) including, e.g., singlet oxygen (O-1(2)), superoxide anion (O-2(-center dot)), and hydroxyl radicals ((OH)-O-center dot), chemicals with extremely high cyto- and potential gen ...

Wiley-V C H Verlag Gmbh2013

Light-responsive polymer nanoreactors: a source of reactive oxygen species on demand

Andrzej Sienkiewicz

Various domains present the challenges of responding to stimuli in a specific manner, with the desired sensitivity or functionality, and only when required. Stimuli-responsive systems that are appropriately designed can effectively meet these challenges. H ...

Royal Soc Chemistry2013

Like a Bolt from the Blue: Phthalocyanines in Biomedical Optics

Hubert van den Bergh

The purpose of this review is to compile preclinical and clinical results on phthalocyanines (Pcs) as photosensitizers (PS) for Photodynamic Therapy (PDT) and contrast agents for fluorescence imaging. Indeed, Pcs are excellent candidates in these fields du ...

Molecular Diversity Preservation International2012

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