Résultats de recherche

JuryProf. Régis HALLEZ (UNamur), PrésidentProf. Jean-Yves MATROULE (UNamur), SecrétaireDr Rob VAN HOUDT (SCK CEN)Dr Kristel MIJNENDONCKX (SCK CEN)Prof. Liselot DEWACHTER (UCLouvain)AbstractThe viable-but-nonculturable (VBNC) state is a type of bacterial dormancy triggered by sublethal stress, where cells remain intact but lose the ability to grow on standard media. This poses challenges for microbial monitoring and public health, as VBNC cells can evade detection and might regain virulence upon resuscitation. Copper compounds are explored as antimicrobial agents, however sublethal Cu concentrations were shown to induce the VBNC state in certain bacteria. This thesis investigates the Cu-induced VBNC state in Cupriavidus metallidurans, a metal-resistant betaproteobacterium, and examines the involvement of its Cu resistance determinants (CRDs). While resuscitation is usually mediated by external factors, we aimed to uncover intrinsic processes that enable spontaneous resuscitation, a rare phenotype lacking mechanistic understanding. Proteomic analysis revealed that expression of CRDs, among others, correlated with mitigated dormancy. Time-resolved profiling showed that VBNC cells exhibit highly dynamic proteomes: VBNC entry involved oxidative stress response, and resuscitation correlated with metabolic reconstitution and the strong induction of periplasmic CRDs. Temporal clustering corroborated the explored proteomic modifications. Through mutational studies we identified the plasmid-encoded copAB system as the minimal resuscitation factor, where integrity of the CopA methionine-rich domain proved critical. ICP-MS analysis indicated that detoxification relies on Cu sequestration rather than export. Altogether, this work uncovers key intrinsic factors and proposes a mechanistic basis for spontaneous resuscitation from the Cu-induced VBNC state in C. metallidurans. These insights refine our understanding of the VBNC state as a dynamic survival strategy and of bacterial Cu resistance.

JuryDr Luca FUSARO (UNamur), PrésidentProf. Carmela APRILE (UNamur), SecrétaireProf. Francesco GIACALONE (Université de Palerme)Prof. Paolo PESCARMONA (Université de Groningen)Prof. Michelangelo GRUTTADAURIA (Université de Palerme)AbstractThis PhD research focused on the design, synthesis, and catalytic evaluation of novel materials based on metal phthalocyanines (MPCs) and imidazolium bromide salts. The initial materials were extensively characterized using a wide range of analytical, spectroscopic, and spectrometric techniques, including solid-state NMR, XPS, TEM, EDX, FT-IR, Raman, CHN analysis, ICP-OES, N₂ physisorption, and TGA. These systems showed remarkable performance in promoting the cycloaddition of CO₂ to epoxides to form cyclic carbonates. Building on these results, a new class of catalysts was developed by covalently anchoring metal phthalocyanines and imidazolium salts onto multi-walled carbon nanotubes (MWCNTs), yielding materials denoted as MPC@MWCNTs. This strategy enabled the creation of a versatile family of catalysts—prepared with different metal centers (Al, Mg, Fe, Ni, Co, Cu, Zn)—while maintaining a unified synthetic approach. The incorporation of MWCNTs was aimed at enhancing both catalytic activity and stability through synergistic support effects. The resulting MPC@MWCNTs were successfully applied in diverse catalytic contexts: CO₂ valorization into cyclic carbonates (Mg-, Fe-, Cu-, and Zn-based systems), nitro-reduction reactions to afford amines (Fe-based system), and electrocatalytic methanol oxidation for energy-related applications (Ni-based system). Overall, this work demonstrated the potential of MPC@MWCNT hybrid materials as robust, tunable, and multifunctional catalysts for sustainable chemical transformations. Assister à l'événement à distance (Teams)

Une conférence donnée en anglais par André Füzfa, Professeur au sein du Département de Mathématique de l'UNamur. Quand : Lundi 14 avril 2025 à 19hOù : Université de Namur - Faculté des sciences - Amphithéâtre S01GratuitEn anglaisPossibilité de rejoindre la conférence en ligne, le lien sera partagé quelques heures avant l'évènement. Retrouvez toutes les infos sur les comptes Facebook (Kapto.UNIVERSEH.) et Instagram (@kapto_universeh) du Kot-à-projet. Un drink sera organisé suite à la conférence.Cette conférence est proposée par "Kàp to UNIVERSEH", le projet sans kot de vulgarisation spatiale de l'Université de Namur, et Local Student Club d'UNIVERSEH. S'inscrire

2025 theme: Stress and emotions in animals The purpose of the symposium aligns with the missions of BCLAS to promote the replacement, reduction and refinement of laboratory animal use by driving reflection, sharing information, providing education and support to the scientific community, authorities and public, in order to lead to an ethical, responsible and qualitative research enabling further improvement in human & animal health.

Abstract Over the past two centuries, advances in healthcare have significantly extended life expectancy by reducing the impact of many diseases. As this progress continues, attention shifts toward more complex illnesses, with cancer emerging as the foremost challenge. Photodynamic therapy (PDT) is a light-activated cancer treatment approved in 1995 that offers a targeted approach by using photosensitizers (PSs) — compounds that, upon light activation, generate reactive singlet oxygen to selectively damage tumor tissue. However, current commercial PSs suffer from several drawbacks: ill-defined composition, poor accumulation in tumors and slow clearance, limited application depths, and insufficient fluorescence for diagnostic imaging. This thesis addresses these limitations by pursuing the development of efficient and partially fluorescent PSs that absorb strongly in the red to near-infrared (NIR) range. The first part of the work focuses on computational tools based on quantum chemistry, particularly density functional theory, to predict molecular properties relevant to PDT. These methods are benchmarked and refined to ensure accurate and efficient screening of candidate compounds. Additionally, a commonly used metric for quantifying charge transfer distance in excited states is reformulated to be independent of molecular symmetry, allowing broader and more robust applicability. In the second part, these tools guide the design of novel PSs. One strategy involves modifying pyrrolopyrrole aza-BODIPY dyes into donor–acceptor structures to enable singlet oxygen generation via spin–orbit charge transfer intersystem crossing (SOCT-ISC). Another approach focuses on a twisted BODIPY compound that achieves photosensitization by facilitating ISC through a distortion of the symmetry. This PS is tuned to absorb NIR light and, in some cases, leverage the SOCT-ISC mechanism. Overall, these efforts did not only yield promising PSs but also provided computational insights to accelerate future developments in the field. Le jury Prof. Guillaume BERIONNI (UNamur), PrésidentProf. Benoît CHAMPAGNE (UNamur), SecrétaireProf. Wouter MAES (UHasselt)Prof. Dirk VANDERZANDE (UHasselt)Prof. Anitha ETHIRAJAN (UHasselt)Prof. Yoann OLIVIER (UNamur)Prof. Wim DEHAEN (KULeuven)Prof. Anna PAINELLI (Universita di Parma)Prof. Mariangela DI DONATO (LENS)Prof. Jan COLPAERT (UHasselt)

Charting the DNA methylome landscape in cancer, chronic disease and phenotype Abstract: Our team has developed some of the first pipelines for genome-scale DNA methylation analysis. Our work has revealed aberrant methylation and expression patterns in several cancer types and revealed new mechanism of epigenetic regulation in cancer cells. We are now applying cutting-edge whole genome scale DNA methylation analysis in tissues as well as well as in cell free DNA (epigenetic liquid biopsy) and epigenetic editing platforms to investigate clinically relevant biomedical questions in cancer (for example, methylation map of colorectal, prostate, lung cancer and pancreatic cancer patients). Our work in epigenetic editing has implication in revealing causal function and new epigenetic regulation. In this talk, I will present the key findings from some of our works over the years and also elaborate on some recent and future directions in understanding the role of DNA methylation events in cancer metastasis, early detection, and treatment monitoring in solid cancers and also in chronic diseases and phenotype. More information on the ILEE website

High-Sensitivity Birefringence Mapping Using Near-Circularly Polarized Light I will describe several techniques for mapping a two-dimensional birefringence distribution, which can be classified according to the optical schemes and principles of work:Illumination geometry (transmitted light/reflected light)Image acquisition (sequential acquisition/simultaneous acquisition)Polarization control (electrically controlled variable retardance/mechanical rotation).This classification facilitates a comparative analysis of the capabilities and limitations in these methods for birefringence characterization. Polychromatic polarizing microscopy (PPM) provides unique capabilities to alternative methods. It leverages vector interference to generate vivid, full-spectrum colors at extremely low retardances, down to < 10 nm. PPM is a significant departure from conventional polarizing microscopes that rely on Newton interference, which requires retardances above 400 nm for color formation. Furthermore, PPM's color output directly reflects the orientation of the birefringent material, a feature absent in conventional microscopy where color is solely determined by retardance.Joint seminar of ILEE & NISM!Le séminaire est accessible à des personnes externes également, pas besoin de s'inscrire. Plus d'infos

Abstract Radiotherapy is a cornerstone of cancer treatment and is currently administered to approximately half of all cancer patients. However, the cytotoxic effects of ionizing radiation on normal tissues represent a major limitation, as they restrict the dose that can be safely delivered to patients and, consequently, reduce the likelihood of effective tumor control. In this context, delivering radiation at ultra-high dose rates (UHDR, > 40 Gy/s) is gaining increasing attention due to its potential to spare healthy tissues surrounding the tumor and to prevent radiation-induced side effects, as compared to conventional dose rates (CONV, on the order of Gy/min).The mechanism underlying this protective effect—termed the FLASH effect—remains elusive, driving intensive research to elucidate the biological processes triggered by this type of irradiation.In vitro models offer a valuable tool to support this research, allowing for the efficient screening of various beam parameters and biological responses in a time- and cost-effective manner. In this study, multicellular tumor spheroids and normal cells were exposed to proton irradiation at UHDR to evaluate its effectiveness in controlling tumor growth and its cytotoxic impact on healthy tissues, respectively.We report that UHDR and CONV irradiation induced a comparable growth delay in 3D tumor spheroids, suggesting similar efficacy in tumor control. In normal cells, both dose rates induced similar levels of senescence; however, UHDR irradiation led to lower apoptosis induction at clinically relevant doses and early time points post-irradiation.Taken together, these findings further highlight the potential of UHDR irradiation to modulate the response of normal tissues while maintaining comparable tumor control.JuryProf. Thomas BALLIGAND (UNamur), PrésidentProf. Stéphane LUCAS (UNamur), SecrétaireProf. Carine MICHIELS (UNamur)Dr Sébastien PENNINCKX (Hôpital Universitaire de Bruxelles)Prof. Cristian FERNANDEZ (Université de Bern)Dr Rudi LABARBE (IBA)

Abstract Due to their unique chemical, physical and photophysical properties, organoboron compounds and in particular triarylboranes play a central role in chemistry and in catalysis. Trivalent neutral boron Lewis acids, which are planar trigonal species, have been shown to exhibit enhanced Lewis acidity and electrophilicities when constrained in a pyramidal trigonal environment. Within the context of the emerging area of geometrically constrained main-group elements, the fundamental experimental and computational investigations of the impact of structural deformation on the physicochemical properties and reactivity of borane derivatives is of interest. This thesis will explore successively the development of geometrically constrained intramolecular FLP and of cationic boron Lewis superacid based on the aza-boratriptycene scaffold, then the synthesis of pyramidalyzed electron-deficient borenium cation with tethered pyridine and NHC ligands embedded in the triptycene scaffold and will finally focus on chiral borenium cations as new Lewis acids. A collaborative work dealing with the combination of the strong 9-sulfonium-10-boratriptycene with hindered Lewis bases is finally performed for developing latent FLP. This work deepens our understanding of the synthesis of constrained boron Lewis acids species, a key step to develop new pyramidal boron Lewis superacids, deblocking new kinds of reactivity in main-group chemistry. For instance, electrophilic Csp2–H borylation reactions of electron-poor aromatics were observed, new unusual binding mode at weakly coordinating anions were discovered and encouraging steps were initiated for reaching new chiral boron-based Lewis acids, opening the path toward new horizons in main-group chemistry.JuryProf. Benoît CHAMPAGNE (UNamur), PrésidentProf. Guillaume BERIONNI (UNamur), SecrétaireProf. Olivier CHUZEL (Aix-Marseille Université)Prof. Raphaël ROBIETTE (UCLouvain)Prof. Stéphane VINCENT (UNamur)

La deadline d'inscription et de soumission pour les abstracts : 20 août 2025.  Plus d'infos sur le site internet de l'Institut NARILIS

Le Congrès des Sciences 2025 s’adresse aux enseignants en sciences (biologie, chimie, physique) et en géographie, et les invite à explorer le thème Eau‑Rêka ! — une immersion interdisciplinaire au cœur des enjeux liés à l’eau, de la qualité des milieux aquatiques à la gestion durable des ressources.Au programme : conférences, ateliers pratiques, visites et moments d’échange entre pairs.Un temps fort de formation continue pour actualiser ses connaissances scientifiques et enrichir ses pratiques pédagogiques.Le Confluent des Savoirs y animera un atelier le 21 août à 15h, consacré à la découverte des habitants microscopiques et macroscopiques des mousses. Les vedettes de cette exploration : les fascinants rotifères bdelloïdes.

Bienvenue à la 1ʳᵉ conférence MG-ERC Cette conférence, en lien avec les thématiques de recherche du département de chimie, a pour objectif de rassembler une centaine de chercheurs travaillant dans les domaines de la chimie des hétéroatomes, de la chimie de coordination, de la catalyse, et de la chimie inorganique. Elle présente une réelle nouveauté en Belgique en termes des domaines couverts, et va permettre aux participants de découvrir des nouveaux concepts, idées et tendances dans ces domaines de recherche récents en chimie. Voici la liste des conférenciers, qui sont des experts mondiaux dans leurs domainesDr. Daniël Broere (Utrecht University, Netherlands)Prof. Agnieszka Nowak-Król (Universität Würzburg, Germany)Dr. Antoine Simonneau (Université Paul-Sabatier, Toulouse, France)Prof. Dr. Sebastian Riedel (Freie Universität, Berlin, Germany)Dr. Arnaud Voituriez (Université Paris-Saclay, France)Prof. Dr. Alessandro Bismuto (Universität Bonn, Germany)Dr. Christian Hering-Junghans (Leibniz-Institut für Katalyse, Germany)Prof. Connie Lu (Universität Bonn, Germany)Prof. Simon Aldridge (University of Oxford, UK)Dr. Ghenwa Bouhadir (Université Paul-Sabatier, Toulouse, France)Prof. Dr. Viktoria Däschlein-Gessner (Ruhr-University of Bochum, Germany)    Dr. Jennifer A. Garden (University of Edinburgh, UK)Prof. Muriel Hissler (Université de Rennes, France)Prof. Jean-François Paquin (Université de Laval, Canada) Plus d’informations et inscription