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See detailUsing IPCAPS to identify fine-scale population structure
Chaichoompu, Kridsadakorn ULg; Fentaw Abegaz, Yazew ULg; Tongsima, Sissades et al

Poster (2017, September 09)

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See detailSynthesis, characterization, and durability study of Pt-Co hollow nanoparticles deposited on carbon xerogel electrocatalysts for Proton Exchange Membrane Fuel Cells (PEMFC)
Zubiaur, Anthony ULg; Asset, Tristan ULg; Olu, Pierre-Yves et al

Poster (2017, September)

Proton exchange membrane fuel cell (PEMFC) catalysts are generally made of carbon black (CB)supported platinum-based nanoparticles. However, the properties of CBs, as described by RodríguezReinoso [1 ... [more ▼]

Proton exchange membrane fuel cell (PEMFC) catalysts are generally made of carbon black (CB)supported platinum-based nanoparticles. However, the properties of CBs, as described by RodríguezReinoso [1], are not optimal for electrocatalysis. A possible solution to the drawbacks of CBs is the use of synthetic nanostructured materials with a controllable and reproducible texture and with a pure, known and constant chemical composition; carbon xerogels (CX) exhibit such properties [2]. Recently, various highly dispersed CX-supported Pt nanoparticles catalysts (Pt/CX) have been synthesized via several methods, such as the strong electrostatic adsorption (SEA) [3] or the charge-enhanced dry impregnation (CEDI) [4]. However, the decrease of the Pt mass contained in the PEMFC electrodes, in particular at the cathode where the oxygen reduction reaction (ORR) is processed, remains a major challenge. Improving the ORR mass activity is currently best achieved by alloying Pt with 3d-transition metal atoms such as cobalt (Co). These alloys perform better than the ORR because the substitution of some Pt atoms by 3d-metal atoms with smaller radius leads to a modified Pt electronic structure [5]. The synthesis and durability of Pt-Co hollow particles/CX (Fig. 1) is currently being studied in our groups. The results indicate that the specific and mass activity of the bimetallic hollow particles dispersed on CX is ca. 10 times higher than that of pure Pt/CB. The first durability results show good stability of the hollow particles structure. Performances and accelerated stress tests (ASTs) in PEMFCs were finally performed. [less ▲]

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See detailCompositional gap at La Picada (CSVZ, Chile) results from critical cristallinity and compaction
Vander Auwera, Jacqueline ULg; Namur, Olivier ULg; Coumont, Valentin et al

Poster (2017, August 16)

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See detailAssessing quality of life using structural equation modeling
Dardenne, Nadia ULg; Pétré, Benoît ULg; Husson, Eddy ULg et al

Poster (2017, August)

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See detailPrevalence of voice disorders among teachers at the beginning of their career
Schiller, Isabel ULg

Poster (2017, August)

Due to the high vocal demands associated with their profession, teachers face an increased risk of developing voice disorders. Research suggests that up to 50 % of experienced teachers are affected. Even ... [more ▼]

Due to the high vocal demands associated with their profession, teachers face an increased risk of developing voice disorders. Research suggests that up to 50 % of experienced teachers are affected. Even student teachers, whose vocal load is still relatively low, report voice problems with a frequency of 20 % (Simberg, Laine, Sala, & Rönnemaa, 2000). Little is known about the prevalence of voice disorders among teachers at the very beginning of their career. In Germany, teachers must complete a two-year teaching practice as part of their professional training after they graduate from university, consisting of attending specialized courses and giving lessons. The aim of this symptom-based study was to determine the prevalence of voice problems among this population. A self-administered questionnaire was answered by 73 German teachers in teaching practice. The prevalence of a voice problem was defined based on the presence of two symptoms that persisted for a minimum of two weeks. Results revealed that 37 % of teachers had voice problems during their teaching practice. Among the most frequent symptoms were hoarseness, an urge to clear one’s throat and problems speaking at a loud voice. Considering that the participants had not even begun teaching full-time, the prevalence of reported voice problems is worrisome. It could be associated with their lacking experience in how to use their voice effectively. The findings highlight the necessity of early intervention programs focusing on vocal hygiene and effective voice use in classroom situations. [less ▲]

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See detailItem purification versus adjustments for multiple comparisons in DIF detection
Drabinova, Adela; Martinkova, Patricia; Magis, David ULg

Poster (2017, July 18)

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See detailDetermining fine population structure using iterative pruning
Chaichoompu, Kridsadakorn ULg; Yazew, Fentaw Abegaz; Tongsima, Sissades et al

Poster (2017, July 10)

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an ... [more ▼]

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an unsupervised clustering algorithm called the iterative pruning method to capture population structure (IPCAPS). Our method supports ordinal data which can be applied directly to SNP data to identify fine-level population structure and it is built on the iterative pruning Principal Component Analysis (ipPCA) algorithm (Intarapanich et al. 2009). The IPCAPS involves an iterative process using multiple splits based on multivariate Gaussian mixture modeling of principal components and Clustering EM estimation as in Lebret et al. (2015). In each iteration, rough clusters and outliers are also identified using our own method called RubikClust. The fixation index (FST) is known to measure a distance between populations and FST = 0.001 may be said to be genetically distinct among the European populations (Tian et al. 2008, Huckins et al. 2014). To observe fine-level population structure using FST, we examined simulated scenarios of one population, 500-8,000 individuals, 5,000-10,000 independent SNPs in HWE (Balding and Nichols 1995), with 100 replicates for each scenario. The simulated SNPs were encoded as additive coding and there was no missing genotype generated. We introduced negative control by subjecting individuals to be separated into two groups using kmeans. We observed that FST values of divided groups were lower than 0.0008, which can be defined as the minimum FST to detect fine-level population structure. To evaluate the performance of our method, we tested different simulated data sets of 2-3 populations, 250 individuals per population, 10,000 independent SNPs in HWE, and FST=[0.0008,0.005], with 100 replicates for each data set. For real-life data sets, we applied the IPCAPS to Thai (Wangkumhang et al. 2013) and HapMap populations. Our method showed that a population classification accuracy was superior to the ipPCA in simulated scenarios of extremely subtle structure (FST=[0.0009,0.005]). In case of the Thai population, results to detect fine-level structure were obtained as well as in case of the HapMap populations. We are convinced that the IPCAPS has a potential to detect fine-level structure and it will be important in molecular reclassification studies of patients once underlying population structure has been removed. [less ▲]

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See detailStable isotopes reveal effects of environmental changes on ecological niches of Iphimediidae amphipods
Michel, Loïc ULg; d'Udekem d'Acoz, Cédric; Frederich, Bruno ULg et al

Poster (2017, July)

When faced with environmental changes, organisms are expected to have some intrinsic ability to adapt through ecological plasticity. However, this process is still poorly understood in many Antarctic ... [more ▼]

When faced with environmental changes, organisms are expected to have some intrinsic ability to adapt through ecological plasticity. However, this process is still poorly understood in many Antarctic invertebrates. Here, we focused on Iphimediidae amphipods, as this widely distributed family shows important ecological diversity. In total, 248 amphipods (19 species) from two widely different zones (the West Antarctic Peninsula, or WAP, and Adélie Land, AL) were studied to elucidate how environment can influence ecological niche parameters. Ecological niches were explored using stable isotope ratios of carbon and nitrogen and the SIBER approach (Jackson et al., 2011). The isotopic niche of the whole amphipod assemblage was wider in WAP than in AL. This was true for both total (proxy of the whole range of resources exploited by animals) and the core (proxy of the most commonly used resources) isotopic niches. The ratio between total and core isotopic niches was smaller in WAP than in AL (4.13 vs. 5.74), suggesting that in WAP, animals commonly use a greater relative percentage of the resources to which they have access. Niche modelling at the specific level revealed that this trend was not found in all taxa. For example, niches of Gnathiphimedia sexdentata and Iphimediella microdentata were bigger in WAP than in AL, following the general pattern. On the other hand, niches of Echiniphimedia echinata and E. hodgsoni had the same width in both areas. Moreover, relative niche overlap between these two species was much higher in WAP (42%) than in AL (20%). Our results indicate that the widely different environmental conditions encountered by the animals in these two zones clearly influence their ecology. Overall, Iphimediidae amphipods tend to exploit more resources in WAP, i.e. in the zone where impacts of global change (temperature increase, sea ice cover decrease) are the strongest. Niche overlap between some closely related (i.e. congeneric) species was also more important in WAP. Ultimately, environmental changes in this region might reinforce these trends, which might lead to competition and perturb amphipod community structure. This research was funded by the Belgian Federal Science Policy Office (BELSPO) in the framework of the vERSO and RECTO projects. [less ▲]

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See detailMean and variance of Dynamic Functional Connectivity in Parkinson’s Disease
Baquero Duarte, Katherine Andrea ULg; Guldenmund, Pieter; Rouillard, Maud ULg et al

Poster (2017, June 29)

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See detailDEVELOPMENT OF A MULTISCALE CONVECTIVE LABSCALE DRYER
Fraikin, Laurent ULg; Salmon, Thierry ULg; Léonard, Angélique ULg

Poster (2017, June 19)

The convective drying technology is currently used in many industries but the industrial process is frequently poorly mastered and some design security factors are used. The lack of optimized conception ... [more ▼]

The convective drying technology is currently used in many industries but the industrial process is frequently poorly mastered and some design security factors are used. The lack of optimized conception rules lead to large energy consumptions. In the same perspective, the use of superheated steam as drying fluid expands and requests the improvement of the knowledge about this specific drying process. For this goal, the PEP’s developed a new convective labscale dryer to conduct various studies. This article presents the new dryer called VESAC. [less ▲]

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See detailSTUDY ON THE STRUCTURAL EVOLUTION OF SEWAGE SLUDGE DURING CONVECTIVE DRYING
Li, Jie; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

Poster (2017, June 19)

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a ... [more ▼]

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a wastewater treatment plant (Grosses Battes WWTP, Belgium) was chosen for both lab-scale experiment and pilot-scale experiment. X-ray macrotomography (resolution: 0.36 mm per pixel) and X-ray microtomography (resolution: 41 μm per pixel) were used to explore the structure evolution of the sludge bed and the single extrudate respectively. 2D cross-sections of the sludge bed and the single extrudate were acquired, which supply a convenient way to investigate the evolution of the structure. The results show that the structure of both the sludge bed and the single extrudate distinctly changes during the drying process. [less ▲]

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See detailStudy of the regulation of β-lactam resistance in Enterococcus hirae
Raymackers, Alice ULg; Maréchal, Maxime; Verlaine, Olivier ULg et al

Poster (2017, June 13)

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See detailImpact of formulation and process parameters on near-infrared spectra: Application for water determination in biopharmaceuticals
Clavaud, Matthieu ULg; Roggo, Yves; Allmendinger, Andrea et al

Poster (2017, June 11)

Traditionally, the water content of freeze-dried biopharmaceuticals is determined by time-consuming methods such as Karl Fischer titration. As a fast and non-destructive method, many studies demonstrated ... [more ▼]

Traditionally, the water content of freeze-dried biopharmaceuticals is determined by time-consuming methods such as Karl Fischer titration. As a fast and non-destructive method, many studies demonstrated the efficiency of Near-Infrared (NIR) spectroscopy for that purpose [1]. In this study, NIR was applied to different freeze-dried monoclonal antibody. The aim was to evaluate the robustness of a NIR model depending on formulation composition and process parameters of the lyophilization parameters, and the benefits of NIR when developing a freeze-drying cycle for a new pharmaceutical product. A full Design of experiments (DoE) was established in order to produce materials with various formulations and various process parameters. As a first step, a calibration model was created and validated. The model creation was based on 4 target lyophilized cycles which were manufactured to obtain samples with different water content concentration. Then, 20 lyophilized cycles were produced according to the DoE. Two levels of protein and sucrose concentration, and two levels of pressure / primary drying temperature and process time were investigated. Furthermore, several samples of each experiment stored at different temperature and relative humidity conditions were evaluated. Chemometrics using Principal Component Analysis (PCA) and Partial Least Squares (PLS) were used to evaluate the process variations and to determine the water content, respectively. NIR is capable to differentiate between different lyophilization process conditions, based on chemometrics. Robust calibration NIR model for water determination was generated against KF independent on lyophilization process parameters and formulation composition. NIR is suitable and robust method for drug product development of freeze-dried formulation. [less ▲]

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See detailBio- and CO2-sourced polyhydroxyurethanes for hydrogels coatings, foams and high performance adhesives
Gennen, Sandro ULg; Panchireddy, Satyannarayana ULg; Grignard, Bruno ULg et al

Poster (2017, June 09)

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and ... [more ▼]

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and industrial fields. Indeed, CO2 can be viewed as a cheap, non-toxic and renewable C1 building block precursor of sophisticated organic molecules and polymers. One representative example of CO2 transformation includes the synthesis of various (bis)cyclic carbonates via CO2/epoxide coupling.1-3 Bis-cyclic carbonates were then valorized as monomers for the synthesis of series of novel low carbon footprint poly(hydroxyurethane)s (PHUs). These polymers are now exploited to produce sustainable materials including foams for thermal insulation,4 hydrogels (for potential biomedical use)5 and high performance adhesives and glues (for metal, glass and wood). [less ▲]

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See detailSeparation, identification and quantification of peptidoglycan fragments by zwitterionic hydrophilic interaction chromatography and capillary electrophoresis coupled to mass spectrometry
Boulanger, Madeleine ULg; Delvaux, Cédric ULg; Raymackers, Alice ULg et al

Poster (2017, June 05)

Bacterial peptidoglycan-derived muropeptides and peptides are soluble fragments acting as messengers in diverse cell-signalling events. As the peptidoglycan wall is a key target of antibiotics, bacteria ... [more ▼]

Bacterial peptidoglycan-derived muropeptides and peptides are soluble fragments acting as messengers in diverse cell-signalling events. As the peptidoglycan wall is a key target of antibiotics, bacteria have developed specific resistance mechanisms based on the detection of these fragments inside their cytoplasm. In our model strain, Bacillus licheniformis, the peptidoglycan dipeptide m-A2pm-D-Glu triggers a beta-lactamase induction. However, the nature and the concentration of cytoplasmic peptidoglycan fragments leading to the dipeptide formation are unknown. Additionally, the muropeptides sensing is involved in the innate immune response toward bacterial invasion and is therefore of considerable importance in eukaryotes self-defence functions. In this context, the development of reliable analytical methods aiming to identify and quantify those fragments in complex samples are of major interest. [less ▲]

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See detailRôle des psychologues spécialisés en neuropsychologie auprès des patients en état de conscience altérée : état des lieux et perspectives
Wauquiez, Grégoire; Radiguer, François; Stephan, Julie et al

Poster (2017, June 02)

Avec les progrès des techniques de soins intensifs et de réanimation, de nombreuses personnes survivent à des lésions cérébrales graves et peuvent notamment présenter dans les suites un état de conscience ... [more ▼]

Avec les progrès des techniques de soins intensifs et de réanimation, de nombreuses personnes survivent à des lésions cérébrales graves et peuvent notamment présenter dans les suites un état de conscience altérée. La création depuis les années 2000 d’unités spécialisées dites “Etats Végétatifs Chroniques / Etats Pauci-Relationnels” témoigne du développement de l’offre de soin dédiée à ces problématiques complexes. De plus en plus d’études scientifiques sont également publiées chaque année sur le sujet de l’évaluation et de la prise en charge de ces patients (ref1). La question du diagnostic d'état d'éveil non répondant ou d'état de conscience minimale constitue entre autres un enjeu majeur pour proposer à ces patients une stimulation adaptée (ref2). Néanmoins, ce domaine d’intervention paraît aujourd'hui encore modérément investi par les psychologues spécialisés en neuropsychologie, professionnels qui semblent pourtant à même d’y contribuer de manière pertinente de par leurs connaissances et leurs compétences (ref3). Où en sont les pratiques sur le terrain et quelles seraient les perspectives de développement à envisager ? Pour tenter de répondre à ces questions, nous avons diffusé une enquête en ligne à destination des neuropsychologues francophones (Belgique, France, Québec et Suisse) en vue de recueillir des données sur la formation, les activités et les attentes de nos collègues. En parallèle, nous avons réalisé une brève revue de la littérature scientifique sur le sujet et sollicité l’avis d’experts concernant les pratiques et spécificités des neuropsychologues auprès de ces patients. Nos premiers résultats mettent en avant 1°) qu’un nombre non négligeable de psychologues spécialisés en neuropsychologie travaillent auprès de patients en état de conscience altérée, 2°) qu'ils ont des connaissances et une pratique spécifique leur permettant d'apporter un réel bénéfice dans le diagnostic et la prise en charge interdisciplinaire de ces patients, et 3°) que le sujet des états de conscience altérée mériterait une place plus importante dans la formation initiale et continue des neuropsychologues afin de contribuer au développement d’une pratique de haut niveau auprès de ces patients tout à fait particuliers. Ces résultats nous feront discuter des questions de la formation initiale, des variétés de pratiques et de la perspective d’une enquête élargie aux pays non francophones. [less ▲]

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See detailMass spectrometry imaging of small xenobiotics on Danio rerio : influence of molecular profiles modification as potential localization asset
Tiquet, Mathieu ULg; Muller, Marc ULg; De Pauw, Edwin ULg

Poster (2017, June 02)

MALDI Mass spectrometry often fail to locate small xenobiotics present in low concentration in tissues due to ion suppression effect. This new method compare tissues of contaminated zebrafish to controles ... [more ▼]

MALDI Mass spectrometry often fail to locate small xenobiotics present in low concentration in tissues due to ion suppression effect. This new method compare tissues of contaminated zebrafish to controles with the statistical tool called receiver operating characteristic. Results cannot directly locate the xenobiotic but can indicate which tissues are affected by the contamination and thus give a hint on the biolocalization. [less ▲]

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See detailAnalyse des pratiques, des représentations et de la tolérance en matière de sexualité adolescente au regard de la consommation pornographique sur Internet
Garcet, Serge ULg; Eloy, Noémie ULg

Poster (2017, June 01)

L’hyper-sexualisation actuelle de l’espace public et la consommation de matériel pornographique semble avoir un impact sur le développement psycho-sexuel adolescent, la tolérance aux pratiques sexuelles ... [more ▼]

L’hyper-sexualisation actuelle de l’espace public et la consommation de matériel pornographique semble avoir un impact sur le développement psycho-sexuel adolescent, la tolérance aux pratiques sexuelles parallèles et l’expérimentation précoce et variée de ces pratiques. Différentes recherches ont été menées auprès d’un panel de plus de 300 adolescents. Les résultats, présentés en synthèses sous forme d’un poster, permettent de rendre une photographie actuelle des pratiques sexuelles adolescentes au regard de la littérature scientifique. Il apparait notamment que 80% des jeunes interrogés se disent consommateurs réguliers de contenus pornographiques. Cette consommation pornographique semble en lien avec le fait d’être plus ouvert aux questions en matière de sexualité, la diversification des pratiques sexuelles, le nombre de partenaires sexuels ou encore le recours à des relations alternatives de types « fuckfsriends » ou « sexting ». La mise en parallèle des pratiques adolescentes en matière de sexualité et de la consommation de pornographie internet a également permis de tenter de répondre à la double interrogation ; L’hyper-sexualisation de l’espace public augmente-t-il la tolérance des jeunes en matière de sexualité ? La pornographie internet influence-t-elle les représentations et pratiques des adolescents en matière de sexualité ? Par extension, cette compilation de résultats, nous a amené à envisager le lien existant entre la consommation précoce et accrue de pornographie chez les adolescents, leur seuil de tolérance aux différentes pratiques sexuelles mises en scène dans ces contenus et la propension que ces jeunes ont à expérimenter ces pratiques, parfois déviantes, au risque de s’inscrire dans la transgression. [less ▲]

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See detailThe acquisition of nouns in children with Specific Language Impairment
Krzemien, Magali ULg; Thibaut, Jean-Pierre; Zghonda, Hela ULg et al

Poster (2017, June 01)

Specific Language Impairment (SLI) is a neurodevelopmental disorder that affects the language development of children with a normal nonverbal intelligence and no history of neurological disorder nor ... [more ▼]

Specific Language Impairment (SLI) is a neurodevelopmental disorder that affects the language development of children with a normal nonverbal intelligence and no history of neurological disorder nor auditory deficit (Leonard, 2014). A difficulty linked to SLI is the poor language productivity and the input dependency that children display compared with their peers: they tend to use a limited variety of verbal forms compared to younger siblings (Conti-Ramsden & Jones, 1997) and use a high proportions of the same verbs as their mothers (Jones & Conti-Ramsden, 1997). Recent studies suggested that these disorders could be linked to a deficit in generalizing constructions (constructions being units of language that vary in complexity and abstractness, Tomasello, 2009) from the input (Leroy et al., 2013). Specifically, some authors proposed that children with SLI would need more exemplars to abstract a given construction from the input and apply it to new instances (Leroy et al., 2013). In this study, we want to broaden this assumption to the acquisition of words: we evaluated the ability of children with SLI to generalize novel words, and in particular relational words. SLI seem indeed to be linked to an impairment in the processing of relations: children with SLI have poorer performance than their age-matched peers in linguistic or non-linguistic analogical tasks, which require to reason about relational structures (Leroy et al., 2014). We draw the hypothesis that children with SLI would need more exemplars in order to generalize words compared to age-matched but also to language-matched peers. We created a novel word extension task to improve this hypothesis: the first part is composed with nine test trials, each associated with a non-word. The child sees one, two, or three exemplars of a novel noun in short animations. The examiner tells him: “This is a /dyfɑ̃/”. Then, the child sees three other animations and the examiner says: “Show me which one of these is a /dyfɑ̃/”. The child has to choose the object that plays the same role as the exemplars among two distractors: an object that looks like one of the exemplar and a non-related distractor. The second part of the task is based on the same protocol but the exemplars are objects that have a specific spatial configuration (like symmetry). Here again, the child sees one, two, or three exemplars of a novel noun associated with the objects. The examiner tells him: “This is a /fegɑ̃/”. Then, the child sees three other objects and the examiner says: “Show me which one of these is a /fegɑ̃/”. The distractors are an object that has the same global form as one of the exemplar but without having the specific configuration required, and the non-related distractor. The participants are 20 children diagnosed with SLI aged from 6 to 12 years-old. Each child is match to a control child in age and non-verbal IQ on the one hand, and to a control child in linguistic age (based on a measure of vocabulary comprehension). Results show that children are better able to extend relational words when presented with several referents of these words, which confirms what has already been found in other experiments (Gentner, 2005). When the feature to be used is a spatial relation between the parts of the objects, children with SLI have more difficulties than age-matched controls extending new words, which confirms that SLI is linked to an impairment in the processing of relations and a greater dependance on perceptual information (Leroy et al., 2014). They also tend to benefit more than age-matched children from the presentation of several referents of a new word in order to extend it, what would mean that they greatly benefit from comparison and variability in order to identify relational similarities. It would be interesting to see if children can learn from several items that relational feature can be pertinent to define categories and extend words, as young children without SLI can do it with shape while children with SLI cannot (Collinson et al., 2015). [less ▲]

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See detailExploration des processus de recollection et de familiarité chez des patients présentant une plainte mnésique : Une étude longitudinale
Simon, Jessica ULg; Collette, Fabienne ULg; Salmon, Eric ULg et al

Poster (2017, June 01)

Les données actuelles suggèrent une altération précoce de la recollection dans les premiers stades de la maladie d’Alzheimer. Par contre, aucun consensus n’a pu être dégagé concernant l’intégrité de la ... [more ▼]

Les données actuelles suggèrent une altération précoce de la recollection dans les premiers stades de la maladie d’Alzheimer. Par contre, aucun consensus n’a pu être dégagé concernant l’intégrité de la familiarité. En effet, certaines études suggèrent une altération précoce de ce processus, alors que d’autres montrent une préservation de celle-ci. Dans ce cadre, nous avons exploré l'impact du type de format de reconnaissance et du matériel sur la recollection et la familiarité chez des patients qui se plaignent de leur mémoire. Nous avons recruté 23 participants âgés contrôles, 9 patients présentant un trouble subjectif de la mémoire (SCI) et 23 patients présentant un trouble cognitif léger (TCL). Les participants ont réalisé une tâche de reconnaissance à choix forcé à deux alternatives et une tâche de reconnaissance Oui-Non incluant des images et des mots. Ces tâches étaient suivies d’une courte évaluation neuropsychologique. Quinze participants âgés contrôles et 23 patients ont participé au suivi, incluant une évaluation neuropsychologique, dans un délai moyen de 21 mois. Nos résultats montrent qu’à l’inclusion, les patients avec TCL avaient des performances moindres en reconnaissance que les deux autres groupes, qui ne différaient pas. De même, ces patients utilisaient moins efficacement la recollection et la familiarité par rapport aux contrôles et aux SCI, qui présentaient des performances similaires. Il n’y avait aucune interaction entre le groupe et le type de format ou le matériel. Lors du suivi, cinq patients avec TCL ont retrouvé un niveau d’efficience cognitive dans la norme et ont été considérés comme des SCI car les plaintes mnésiques étaient toujours présentes. Sur la base de l'adaptation française du test de rappel libre et indicé (RLRI-16), nous avons calculé une pente de déclin mnésique pour chacun de nos patients. Nous avons observé que les indices de recollection et de familiarité étaient expliqués par les pentes de déclin calculées sur le nombre total d’items rappelés librement. Ainsi, nous avons observé un déclin de la recollection et la familiarité dans le groupe de TCL mais pas dans celui des SCI, bien que les deux groupes se plaignent de leur mémoire. En outre, l'efficacité de la familiarité pourrait prédire un déclin cognitif futur. [less ▲]

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See detailEfficacité de la combinaison des méthodes explicite et implicite pour intervenir sur les difficultés morphosyntaxiques
Houben, Lauren; Maillart, Christelle ULg; Leroy, Sandrine ULg

Poster (2017, June 01)

Pour que la logopédie puisse s’appuyer sur une pratique basée sur les preuves (Evidence-Based Practice), il est nécessaire de disposer d’études traitant de l’efficacité des interventions. Dans la ... [more ▼]

Pour que la logopédie puisse s’appuyer sur une pratique basée sur les preuves (Evidence-Based Practice), il est nécessaire de disposer d’études traitant de l’efficacité des interventions. Dans la littérature scientifique, deux approches sont mises en avant pour pallier aux difficultés morphosyntaxiques: les méthodes implicites opposées aux méthodes explicites. Les méthodes implicites s’avèrent pertinentes chez les enfants d’âge préscolaire, en raison de leurs faibles habiletés métalinguistiques. Ces méthodes réfèrent aux méthodes de facilitation grammaticale (imitation, modelage, stimulation focalisée et reformulation) et à l’approche basée sur l’usage. Cette dernière tient compte de l’apprentissage progressif des différentes structures grammaticales chez les enfants ayant un développement typique (notamment Riches, 2013). Les méthodes explicites offrent un apprentissage explicite du langage. Elles reposent sur le constat selon lequel, en raison d’un déficit de la mémoire procédurale, les enfants ayant des troubles du langage ne parviendraient pas à apprendre implicitement le langage. Actuellement, les résultats obtenus quant à l’efficacité de ces méthodes semblent contradictoires. Dès lors, la combinaison des deux types d’approches pourrait être envisagée. Actuellement, une seule étude (Smith-Lock et al., 2013) s’est intéressée à cette combinaison des deux méthodes et a prouvé son efficacité. Bien que cette étude soit assez prometteuse quant aux bienfaits d’une rééducation s’appuyant sur plusieurs méthodes, des recherches complémentaires sont indispensables. [less ▲]

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See detailAgression sexuelle lors d’un conflit dans les relations amoureuses : Un statut spécifique
Courtain, Audrey ULg; Glowacz, Fabienne ULg

Poster (2017, June 01)

Le CADRI (Conflict in Adolescent Dating Relationships Inventory ; Wolfe et al., 2001) est un questionnaire portant sur les fréquences de violence dans les relations amoureuses (VRA), dont la dimension ... [more ▼]

Le CADRI (Conflict in Adolescent Dating Relationships Inventory ; Wolfe et al., 2001) est un questionnaire portant sur les fréquences de violence dans les relations amoureuses (VRA), dont la dimension sexuelle. Il s’inscrit dans la continuité du CTS-2 (Conflict Tactics Scale ; Strauss et al., 1996) utilisé dans le cadre des violences conjugales, ces deux outils ayant été conçus sur base de la théorie du conflit. Or, celle-ci postule que « conflict is an inevitable part of human association, whereas violence as a tactic to deal with conflict is not. » (Strauss et al., 1996, p.284). Ainsi, agresser sexuellement sa petite amie ou son petit ami, est-ce du ressort d’un contexte conflictuel, ou bien de la violence sexuelle : quelle en est la spécificité ? Méthodologie : Deux versions du CADRI ont été administrées en passation groupale à des étudiants (N>200, 15-23 ans) en Belgique francophone : la première étant une version modifiée où la consigne introductive ne circonscrivait pas les items de violence à du conflit, la seconde étant la version-type délimitant les items de violence à un contexte de conflit. Résultats : Les scores diffèrent selon la version-type et la version modifiée du CADRI, et selon que nous nous situons sur le versant de la perpétration ou de la victimisation sexuelle, ainsi que selon le sexe des répondants. Discussion : Alors que l’importance des consignes introductives est globalement reconnue, l’implication conceptuelle de certaines est loin d'être négligeable pour la description, la compréhension et la prévention de l'agression sexuelle comme VRA. [less ▲]

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Peer Reviewed
See detailMicroplastics found in the stomach contents of Squalius cephalus from the Seine River
Collard, France ULg; Gilbert, Bernard ULg; Eppe, Gauthier ULg et al

Poster (2017, June)

Microplastics (plastics < 5 mm) are emerging pollutants of growing concern. Since the 2000s their abundance, degradation and impacts on wildlife are more and more studied and understood. However, few data ... [more ▼]

Microplastics (plastics < 5 mm) are emerging pollutants of growing concern. Since the 2000s their abundance, degradation and impacts on wildlife are more and more studied and understood. However, few data are available particularly in freshwater ecosystems. Some fish species have plastic in their stomach contents such as: Gobio gobio, Alburnus alburnus, Leuciscus leuciscus while other species have not. In controlled conditions, microplastics were found to cause negative impacts in fish: leaching of micropollutants, endocrine disruption, hatching inhibition and decrease of growth rate of larvae. The first step in the understanding of these impacts is the quantification and the characterisation of ingested plastics by organisms in the field. Plastics and other anthropogenic particles (textile fibres) were isolated from 40 stomachs of Squalius cephalus (the European chub) collected in the Seine River (Paris) in August 2016. One station is upstream and the three others are downstream of the Paris Megacity conurbation. This megacity exerts a great pressure on the Seine River. Plastics were isolated thanks to a method using sodium hypochlorite and all particles were then analysed by Raman spectroscopy. The method consists in a degradation overnight of the organic matter in the stomach contents by sodium hypochlorite. This mixture is then filtrated and particles longer than 5 µm are resuspended into an ethanol (99%) solution for centrifugation. The precipitate, containing all particles denser than ethanol, is collected (1.3 ml) and spread on a mount for Raman spectroscopy. Several lasers were used, depending on the particle’s colour. Spectra were recorded with an accumulation ranging from 5 to 50s. Preliminary results showed that 7 individuals out of 25 already analysed (28%) had ingested at least one anthropogenic particle (AP). Eight APs were found and characterized, the majority of them (7) being dyed fibres. One of these fibres was made of a plastic polymer, the polyethylene terephthalate. The others were made of an undetermined material as Raman analyses gave only information on the dye. The eighth particle was a fragment of polypropylene. It is the first time that fish are studied as a part of plastic pollution in the Seine River. All isolated particles have been analysed leading to precise results. The percentage of occurrence is in the common range of other studies while much lower than the European flounder coming from the River Thames and higher than fish coming from Geneva Lake. It is not surprising that the majority of APs were fibres as another study in the river Seine found that the fibres concentration in water is far greater than the fragments concentration, as well as in urban runoff. It is also possible that the retention time of fibres in the gut is longer than fragments. Toxicological impacts of fibre ingestion is still unknown despite their ubiquity in many freshwater environments. [less ▲]

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See detailThe Split-Band Interferometry Approach to Determine the Phase Unwrapping Offset
Libert, Ludivine ULg; De Rauw, Dominique ULg; d'Oreye, Nicolas et al

Poster (2017, June)

This poster presents an approach based on the Split-Band Interferometry to solve the ambiguities introduced during the phase unwrapping of separate regions.

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See detailSafety update on dapagliflozin (DAPA) across the phase 2b/3 clinical trial program
Jabbour, Serge; Seufert, Jochen; SCHEEN, André ULg et al

Poster (2017, June)

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See detailNew data on the Mesozoic radiation of chelonioids
Scavezzoni, Isaure ULg; Fischer, Valentin ULg

Poster (2017, June)

"Turtles" (Testudines) form a successful group of reptiles with several terrestrial, marine and fresh-water species. Their peculiar and somewhat constrained morphology (i. e. : carapace incorporating ribs ... [more ▼]

"Turtles" (Testudines) form a successful group of reptiles with several terrestrial, marine and fresh-water species. Their peculiar and somewhat constrained morphology (i. e. : carapace incorporating ribs, curved limbs, anapsid skull exempt of temporal fenestrae) and ecology has often obscured their relationships and, hence, their evolutionary history, notably in marine turtles (chelonioids). Modern chelonioids are divided in two clades (i. e. : shoft-shelled turtles and hard-shelled turtles) supported by distinct morphological and embryological characters. Their origin is traced back up to the Cretaceous, along with a series of extinct forms, many of which being collectively known as Protostegidae. Fossil evidence show that at least five clades of marine turtles were roaming the seas at the end of the Cretaceous. In fact, chelonioids appeared during the first stages of the Early Cretaceous and quickly exploded to reach a high level of disparity at the lowermost part of the late Cretaceous. Therefore, the Mesozoic radiation of chelonioids must have happened during the "middle" Cretaceous (especially the Aptian-Albian interval). However this radiation is poorly understood as the phylogenetic relationships of marine turtles are not resolved yet. Bringing new data may help resolve these issues, and it is the exact reason why the genus Rhinochelys is being investigated. [less ▲]

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See detailProfiling inferior left dorsal premotor cortex: when Area 55b meets Premotor Eye-Field
Genon, Sarah ULg; Reid, Andrew; Langner, Robert et al

Poster (2017, June)

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See detailImpact of 3’-­‐sialyllactose and Bifidobacterium crudilactis on infant feces microbial composition and virulence modulation of Escherichia coli O157:H7, using the SHIME® gastrointes6nal model
Bondue, Pauline ULg; Lebrun, Sarah ULg; Crevecoeur, Sébastien ULg et al

Poster (2017, June)

Bifidobacterium crudilactis, a bacterial species from bovine origin, growths on bovine milk oligosaccharides (BMO). Cell free spent media (CFSM) from B. crudilactis and 3’-sialyllactose (3’SL), a major ... [more ▼]

Bifidobacterium crudilactis, a bacterial species from bovine origin, growths on bovine milk oligosaccharides (BMO). Cell free spent media (CFSM) from B. crudilactis and 3’-sialyllactose (3’SL), a major BMO, modulated Escherichia coli O157:H7 virulence gene expressiona. In this study, the SHIME® gastrointestinal model was inoculated with 4 different treatments: 3’SL (ttm1), B. crudilactis (ttm2), 3’SL and B. crudilactis (ttm3) and CFSM from 3’SL and B. crudilactis culture (ttm4). In each section of the colon, samples were collected and analysed for short chain fatty acid (SCFA) concentration using HPLC, microbial populations using 16S rDNA metagenetic analysis and correlated with E. coli O157:H7 virulence gene expression. The results showed that SCFA levels were stable during the experiments. Metagenetic analysis showed a microbial diversity in transverse (TC) and descending colon (DC) close to feces, dominated by Bacteroides, Prevotella and Fusobacterium, while the ascending colon (AC) showed a different microbial diversity dominated by Veillonella. Ttm4 and ttm2 induced mainly a down-regulation of virulence genes: fliC in DC with ttm4, and luxS, stx1, qseA in AC, DC or TC with ttm2. Ttm1 also showed a down-regulation of fliC in DC, similar to the one observed with ttm4, but this was associated with an up-regulation of fliC and stx1 in AC or TC. Finally, ttm3 showed slight upregulation of ler, fliC and qseA in AC. These results show that ttm4 and ttm2 might have a positive effect against virulence expression of E. coli O157:H7. However, this trend has to be validated with the further replicates on the SHIME® system. [less ▲]

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See detailUntargeted serum metabolite profiling of colorectal cancer using GC-Orbitrap technology
Di Giovanni, Nicolas ULg; Cojocariu, C; Silcock, P et al

Poster (2017, June)

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Peer Reviewed
See detailStranger harassment: perception, tolerance and the influence of gender identities and gender stereotypes
Goblet, Margot ULg; Glowacz, Fabienne ULg

Poster (2017, May 31)

Stranger harassment is defined as gender based harassment in public spaces. Despite its frequency and its detrimental consequences, research has barely begun to address this phenomenon. Stranger ... [more ▼]

Stranger harassment is defined as gender based harassment in public spaces. Despite its frequency and its detrimental consequences, research has barely begun to address this phenomenon. Stranger harassment is in the eye of the beholder. Gender differences and contextual factors are decisive for its interpretation (Fairchild, 2010; Rotundo, Nguyen and Sackett, 2001). The aim of this study is to estimate contextual factors of stranger harassment and more precisely to examine the influence of gender identities and gender roles on perception and tolerance of stranger harassment within a population of young women and men aged 18-35. Two methods of data collection are used, a paper questionnaire and an on-line questionnaire. The sample should include more than 600 subjects. Participants are surveyed regarding their global life satisfaction (Satisfaction With Life Scale, Diener et al., 1985), personal experiences of stranger harassment (Sexual Experience Questionnaire, Fairchild, 2010) and the context of occurrence and the consequences of those experiences on several aspects of their life. Acceptation and tolerance of sexual harassment (Sexual Harassment Attitude Scale, Mazer et Percival, 1989), identification to gender roles (short French version of Bem Sex-Roles Inventory, Fontayne et al., 2000) and experiences of sexual victimization are also addressed. Results will provide us an overview of stranger harassment and its occurrence. Some risk factors may be identified, as experiences of sexual victimization that may influence tolerance of stranger harassment. Furthermore, the influence of gender roles and gender identities may be crucial for the understanding of stranger harassment as a gender based behavior [less ▲]

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See detailFemmes auteures d’infraction à caractère sexuel en guidance sous contrainte judiciaire : entre représentations et réalités ?
Glowacz, Fabienne ULg; Lagneaux, Julien; MALEMPRE, Marc et al

Poster (2017, May 31)

La délinquance a été le plus souvent conjuguée au masculin alors que la violence des femmes est restée longtemps ignorée. Il en est de même pour la délinquance sexuelle agie par les femmes qui est étudiée ... [more ▼]

La délinquance a été le plus souvent conjuguée au masculin alors que la violence des femmes est restée longtemps ignorée. Il en est de même pour la délinquance sexuelle agie par les femmes qui est étudiée depuis peu et est reconnue tout en étant encore méconnue. Notre étude porte sur l’analyse de 23 dossiers émanant de 4 centres de santé mentale spécialisés en Belgique qui ont notamment pour mission de dresser des avis motivés à la demande d’autorité mandante dans le cadre d’un sursis probatoire, d’une libération probatoire ou définitive. L’analyse de contenu des dossiers a permis d’identifier les caractéristiques psychologique, sociale, sexuelle et criminologique des sujets ainsi que la nature des infractions commises et le profil de victimes. Dans la lignée des travaux en matière de délinquance non sexuelle, nous avons repris plusieurs questions dont celles du statut de la femme en tant que auteure et co-auteure, de la présence de troubles psychopathologiques, de l’usage de violences physiques, des antécédents judiciaires ainsi que des dynamiques familiales dans lesquelles elles ont évolué. Plus spécifiquement à la délinquance sexuelle, la sexualité et le rapport aux victimes et les victimisations antérieures ont été analysées pour compléter le portrait du fonctionnement de ces femmes. Les résultats de cette étude ont été confrontés aux représentations des travailleurs de ces centres recueillis à partir de Focus group. [less ▲]

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See detailLes limites de l’administration de la PCL - R à une population de sujets schizophrènes dans le contexte médico-légal
Englebert, Jérôme ULg; Matteucci, Marie; De Page, Louis et al

Poster (2017, May 31)

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See detailImpact of circulation changes on the long-term trend of stratospheric hydrogen fluoride at five NDACC stations
Prignon, Maxime ULg; Bernath, P.F.; Blumenstock, T. et al

Poster (2017, May 29)

Hydrogen fluoride is mainly produced by the photolysis of anthropogenic source gases such as the chlorofluorocarbons (CFC), the hydrochlorofluorocarbons (HCFC) and the hydrofluorocarbons (HFC). These ... [more ▼]

Hydrogen fluoride is mainly produced by the photolysis of anthropogenic source gases such as the chlorofluorocarbons (CFC), the hydrochlorofluorocarbons (HCFC) and the hydrofluorocarbons (HFC). These families of species are known for contributing to ozone depletion and/or to the greenhouse effect. It is thus essential to regulate and monitor their emissions. Despite the fact that the Montreal protocol (1987) has succeeded to reduce and then suppress the CFC emissions, HF is still increasing in the stratosphere because of ongoing emissions of the HCFC and HFC substitution products. In the framework of the recent studies demonstrating the influence of stratospheric circulation changes on the trend of long-lived tracers (e.g. hydrogen chlorine), we decided to investigate the impact of these circulation changes on HF. To achieve this objective, the rates of changes over time of HF total/partial columns at various latitudes of the globe will be determined and critically discussed. Fourier Transform Infrared data produced at five NDACC sites (Kiruna – 68°N, Jungfraujoch – 46°N, Izana – 28°N, Lauder 45°S and Arrival-heights – 78°S) and satellite data (HALOE and ACE) will be used for this study. This preliminary selection of ground-based stations allows to cover both hemispheres and our period of investigation (last two decades). Finally, in order to support our data interpretation, two SLIMCAT simulations (standard and fixed dynamics) will also be included. [less ▲]

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See detailTh17 cells impact on xenogeneic graft-versus-host disease
Delens, Loïc ULg; SERVAIS, Sophie ULg; Ehx, Grégory ULg et al

Poster (2017, May 24)

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See detailAn anticancer molecule stemming from a plant root produced in a bioreactor
Vassaux, Antoine; Tarayre, Cédric ULg; Delvigne, Frank ULg et al

Poster (2017, May 24)

Secondary metabolites produced by plants or their symbionts have already shown specific properties: anticancer, anti-inflammatory, antibacterial, antifungal effects, etc. Astin C is a non-ribosomal ... [more ▼]

Secondary metabolites produced by plants or their symbionts have already shown specific properties: anticancer, anti-inflammatory, antibacterial, antifungal effects, etc. Astin C is a non-ribosomal peptide (secondary metabolite) produced by the fungus Villosirosea asteris, endosymbiont of the medicinal plant Aster tataricus, which has shown an interesting anticancer activity. The current challenge is the production of the molecule on a large scale and in higher quantities, either from the original fungus through fermentation technologies, or by a heterologous yeast strain having integrated the genes involved in the astin C biosynthesis pathway. The purpose of this workshop is to highlight the implementation possibilities of a strain producing a metabolite of interest. [less ▲]

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See detailStudy of VOCs in the interaction between Banana and Foc TR4
Berhal, Chadi ULg; De Clerck, Caroline ULg; LEVICEK, Carolina et al

Poster (2017, May 23)

Banana fruit (Musa sp.) ranks fourth in term of worldwide production, and has economical and nutritional key values. The popular and most dominant variety of the dessert banana group is the Cavendish ... [more ▼]

Banana fruit (Musa sp.) ranks fourth in term of worldwide production, and has economical and nutritional key values. The popular and most dominant variety of the dessert banana group is the Cavendish variety. Nowadays, the Cavendish is endangered by the newly emergent race of the Panama disease, caused by the fungal pathogen Fusarium oxysporum f.sp. cubense TR4 (Foc TR4). Despite the importance of the Volatile Organic Compounds (VOCs), which are secondary metabolites with a high vapour pressure, in their utility in the plant protection processes, they were never documented as a way to manage this disease on Cavendish. Thus, the aim of this PhD thesis is to study the VOCs in the specific interaction Cavendish/Foc TR4, as a way to manage this threat. Based on the work previously done with other plants at Gembloux Agro-Bio Tech/University of Liège/Belgium, a protocol was optimized for the extraction of the banana plant’s VOCs. And in parallel, models of in-vitro and in-vivo inoculations are under development, in order to distinguish the root zone from the upper part of the plant in the study. The results of the first analysis showed that the majority of the Cavendish VOCs belongs to the terpenes group, as well as ketones and an organic ester. The identified key VOCs of the interaction will be subject to toxicity tests, in order to determine their effect on the development of the plant and the pathogen. The banana plant is a staple food for more than 400 Million people in the world, while this disease persists as a major threat for its production, and this original study could contribute to the fight against this threatening disease. [less ▲]

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See detailDesign of polyphosphoester-based drug delivery systems by efficient thiol-ene reaction
Riva, Raphaël ULg; Vanslambrouck, Stéphanie; Ergül, Zeynep ULg et al

Poster (2017, May 23)

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromolecules, polyphosphoesters (PPE) are appealing polymers for biomedical applications. In contrast to ... [more ▼]

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromolecules, polyphosphoesters (PPE) are appealing polymers for biomedical applications. In contrast to polyesters, PPE properties and functionality are easily tuned via the chemical nature of the lateral chains. To enhance the drug loading capacity of PPE-based micelles used as carriers for the delivery of poorly soluble drugs, an efficient strategy to increase the lipophilicity of the PPE block of polyethylene oxide (PEO)-b-PPE amphiphilic copolymers has been investigated. A PEO-b-PPE copolymer bearing pendant vinyl groups along the PPE block was synthesized and then modified by thiol-ene click reaction with thiols bearing either a long linear alkyl chain (dodecyl) or a tocopherol moiety. Ketoconazole was used as model for hydrophobic drugs. Comparison of the loading contents and release profiles with PEO-b-PPE bearing shorter pendant groups is presented evidencing the key role of the structure of the pendant group on the PPE backbone. Finally, the low cytotoxicity of these novel PEO-b-PPE copolymers was also demonstrated. The tocopherol derivative was evidenced as particularly promising for drug delivery systems. [less ▲]

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See detailA surprising and dramatic neuroendocrine-immune phenotype of mice deficient in Growth Hormone-Releasing Hormone (GHRH)
Farhat, Khalil; Bodart, Gwennaëlle ULg; RENARD, Jeanne de Chantal ULg et al

Poster (2017, May 23)

In the framework of close interactions between the immune and neuroendocrine systems, Growth Hormone (GH) has been proposed to exert significant effects on the immune system, but there is not yet a ... [more ▼]

In the framework of close interactions between the immune and neuroendocrine systems, Growth Hormone (GH) has been proposed to exert significant effects on the immune system, but there is not yet a consensus about GH immunomodulatory properties. These studies investigated the immune and anti-infectious response of dwarf Ghrh-/- mice presenting a severe deficiency of the GHRH/GH/IGF-1 axis. In basal conditions, thymic parameters and T-cell responses of Ghrh-/- mice were not severely affected but a constant B-cell lymphopaenia was observed. Thus, we investigated vaccine and anti-infectious responses of Ghrh-/- mice toward Streptococcus pneumonia, a B-dependent pathogen, Ghrh-/- mice were unable to trigger production of specific IgM and IgG against serotype 1 pneumococcal polysaccharide (PPS) after vaccination with either native PPS (Pnx23) or protein-PPS conjugate (Prev-13) vaccines. These vaccines both include the serotype 1 (our S.pneumoniae strain) and provide an effective protection in mice. A short GH supplementation to Ghrh-/- mice (1 daily injection of 1 mg/kg GH for 4 weeks) restored IgM and IgG response to Pnx23 vaccine but not to Prev-13. This suggests that GH could exert distinct impacts upon spenic areas. Furthermore, after intranasal instillation of a non-lethal dose (defined by the full clearance by WT C57BL/6 mice after 24h) of serotype 1 S.pneumoniae, Ghrh-/- mice exhibited a dramatic susceptibility. This was proved by a marked time-dependent increase in pulmonary bacterial, a septicemia already 24h after infection and a survival limit of 72h. We also observed a dramatic decrease in lung B- and T-cell populations and an increase in proportion of inflammatory macrophages. By contrast, wild-type and heterozygote mice completely cleared S.pneumoniae infection after 24h. In conclusion, our data show without ambiguity that the somatotrope GHRH/GH/IGF-1 axis plays an important and unsuspected role in defense against S.Pneumoniae. [less ▲]

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See detailPrecision synthesis and characterization of novel functional polymers
Scholten, Philip ULg; Debuigne, Antoine ULg; Demarteau, Jérémy ULg et al

Poster (2017, May 23)

Among controlled radical polymerisation techniques, cobalt-mediated radical polymerisation (CMRP) has proven to be a valuable alternative in polymerising unreactive and unconjugated monomers of many ... [more ▼]

Among controlled radical polymerisation techniques, cobalt-mediated radical polymerisation (CMRP) has proven to be a valuable alternative in polymerising unreactive and unconjugated monomers of many different monomer classes under mild conditions, including α-olefins. In a reversible deactivation mechanism, a cobalt complex reversibly traps the active growing chains and converts them into dormant species, avoiding side reactions and allowing for a controlled polymerisation. A fine control over the architecture is possible and allows to synthesise a large diversity of unprecedented block and alternating copolymers. Furthermore, functionalisation of the α- and ω-chain ends is now also possible. In this poster, the polymerization of different vinyl monomers using CMRP has been investigated to design highly functional materials under mild experimental conditions. The copolymerisation behaviour of these novel monomers was examined, and the structure and thermal properties of the new copolymers were investigated. [less ▲]

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See detailÉdition et étude de Gerard du Frattre, compilation épique du XVIe siècle
Lambert, Adélaïde ULg

Poster (2017, May 23)

Présentation du projet de thèse de doctorat.

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See detailUnprecendeted fluoroalkene-based copolymers through cobalt-mediated radical polymerization
Demarteau, Jérémy ULg; Ameduri, Bruno; Ladmiral, Vincent et al

Poster (2017, May 22)

The precision design of fluorinated copolymers is challenging but also attractive for future developments in a wide range of applications involving fluoropolymers, such as advanced coatings or ... [more ▼]

The precision design of fluorinated copolymers is challenging but also attractive for future developments in a wide range of applications involving fluoropolymers, such as advanced coatings or purification membranes. In particular, controlling the radical polymerization of fluoroalkenes remains extremely difficult because of the high reactivity of these monomers due to the lack of resonance stabilizing group on their double bond. Herein, Cobalt-Mediated Radical Polymerization (CMRP) was used to efficiently control the bulk copolymerization of perfluorohexylethylene (PFHE) and vinyl acetate (VAc). Well-defined statistical poly(PFHE-stat-VAc) copolymers with different compositions (0 < FPFHE < 0.5) were obtained accordingly. In some cases, fluorinated monomer content as high as 80 % by weight were achieved. Reactivity ratios were determined (rVAc = 0.18 and rPFHE = 0) and emphasized a clear tendency for alternation. Single step approach and sequential polymerization were assessed for the synthesis of novel PFHE/VAc block copolymers. Finally, the acidic hydrolysis of the pendant ester groups of these block copolymers led to the formation of novel highly amphiphilic macromolecules bearing a PVOH hydrophilic segment and a hydrophobic PFHE-based block. [less ▲]

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See detailProtein encapsulation into nanostructured CaCO3 microparticles templated by PEO-b-polyphosphoester using a supercritical CO2 process
Ergül, Zeynep ULg; Debuigne, Antoine ULg; Calvignac, Brice et al

Poster (2017, May 22)

The use of calcium carbonate microparticles is becoming more and more attractive in biomedical applications as proteins carriers for their controlled delivery in the body. We investigate the protein ... [more ▼]

The use of calcium carbonate microparticles is becoming more and more attractive in biomedical applications as proteins carriers for their controlled delivery in the body. We investigate the protein encapsulation by in situ precipitation of CaCO3 particles prepared by a process based on supercritical CO2 and using a new type of degradable well-defined double hydrophilic block copolymer composed of poly(ethylene oxide) and polyphosphoester block with an affinity for calcium like poly(phosphotriester)s bearing pendent carboxylic acids on each repeating monomer unit which evidenced an efficient structure for templating the formation of CaCO3 leading to unprecedented small-sized particles. Lysozyme was chosen as a model for therapeutic protein for its availability and ease of detection. It was found that by this green process, loading into the CaCO3 microparticles with a diameter about 2 μm can be obtained as determined by scanning electron microscopy. A protein loading up to 6.5% active lysozyme was measured by a specific bioassay (Micrococcus lysodeikticus). By encapsulating fluorescent-labelled lysozyme (lysozyme-FITC), the confocal microscopy images confirmed its encapsulation and suggested a core–shell distribution of lysozyme into CaCO3. [less ▲]

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See detailFunctional emulsion-templated porous polymers by macromolecular surfactant anchoring strategies
Mathieu, Kevin ULg; Jérôme, Christine ULg; Debuigne, Antoine ULg

Poster (2017, May 22)

Macroporous polymer monoliths with interconnected structures have attracted considerable interest in the fields of supported catalysis, chromatography, water purification, etc. A popular and ... [more ▼]

Macroporous polymer monoliths with interconnected structures have attracted considerable interest in the fields of supported catalysis, chromatography, water purification, etc. A popular and straightforward synthesis approach for such open-cell polymers is based on the polymerization of high internal phase emulsion (HIPE). Advanced functional polyHIPEs were also produced via different post-modification strategies but the latter often consists in tedious multi-step processes. This communication aims at reporting an efficient one-pot macromolecular surfactant-assisted method for the simultaneous synthesis and chemical functionalization of macroporous polyHIPEs. Briefly, amphiphilic block copolymers prepared by nitroxide-mediated radical polymerization (NMP) or reversible addition-fragmentation chain transfer (RAFT) were used as HIPE stabilizers and grafted at the surface of the walls of polyHIPE during the polymerization process. The impact of the controlled radical polymerization mechanism on the porous structure, openness and functionalization of the monoliths will be discussed. This strategy was also implemented with alkyne-terminated copolymers in order to decorate the surface of the polyHIPE’s cavities with “clickable” moieties which broadens the scope of functional macroporous polymers. [less ▲]

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See detailPERFORMANCES D’UNE MINI POMPE À CHALEUR RÉVERSIBLE FONCTIONNANT SUR L’AIR EXTRAIT : ÉTUDE NUMERIQUE ET EXPERIMENTALE
Ransy, Frédéric ULg; Gendebien, Samuel ULg; Lemort, Vincent ULg

Poster (2017, May 22)

La majeure partie de la consommation d’énergie des immeubles à appartement dits « basse énergie » est liée à la production d’eau chaude sanitaire et aux pertes par ventilation. De plus, ces immeubles sont ... [more ▼]

La majeure partie de la consommation d’énergie des immeubles à appartement dits « basse énergie » est liée à la production d’eau chaude sanitaire et aux pertes par ventilation. De plus, ces immeubles sont soumis à un risque de surchauffe non négligeable en été. Afin de minimiser leur consommation d’énergie, les systèmes HVAC utilisés dans ces bâtiments se doivent d’être performants et multitâches. Dans cette optique, l’Université de Liège teste actuellement une mini-pompe à chaleur réversible sur air extrait. Cet article présente les résultats expérimentaux obtenus en laboratoire et démontre quelles sont les variables qui influencent les performances de cette machine. Un modèle polynomial est également proposé. [less ▲]

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See detailLaccase detoxification of lignocellulose hydrolysate
Cornet, Iris; Soti, Valentin; Richel, Aurore ULg et al

Poster (2017, May 22)

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See detailSynthesis of cross-linked P(HEMA) particles in supercritical carbon dioxide for protein delivery
Parilti, Rahmet ULg; Howdle, Steven M.; Jérôme, Christine ULg

Poster (2017, May 22)

This project aims to develop a novel one-pot strategy to obtain well-defined cross-linked particles able to carry peptides/proteins in their core, as along with targeting and/or imaging agents on their ... [more ▼]

This project aims to develop a novel one-pot strategy to obtain well-defined cross-linked particles able to carry peptides/proteins in their core, as along with targeting and/or imaging agents on their surface. In addition to this objective, polymerisations will be carried out in supercritical carbon dioxide (scCO2), which confers environmentally benign features to the process. Here, we investigate the feasibility of free radical dispersion polymerizations of 2-hydroxyethyl methacrylate (HEMA) in scCO2. In order to ensure the successful dispersion in scCO2 novel diblock CO2-philic surfactants are employed. These diblock surfactants are formed from two different segments, a CO2-phobic block which has an affinity to the growing particles and a second CO2-philic block that ensures surfactant solubility. [less ▲]

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See detailLa nature des intérêts spécifiques distingue les personnes avec et sans retard de langage.
Chiodo, Liliane ULg; Majerus, Steve ULg; Eusèbe, Sandrine et al

Poster (2017, May 20)

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See detailSchizophrénie et psychopathie : Analyse des difficultés d’objectivation diagnostique à partir de la PCL-R
Matteucci, Marie; Englebert, Jérôme ULg; De Page, Louis et al

Poster (2017, May 20)

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See detailLa modalité est importante quand on mène un jugement de reconnaissance basées sur la fluence, mais les patients atteints d’amnésie ne s’en soucient pas
Thonnard, Adeline; Geurten, Marie ULg; Willems, Sylvie ULg

Poster (2017, May 20)

La reconnaissance chez les patients amnésiques repose principalement sur le sentiment de familiarité. Plusieurs études indiquent que ce sentiment de familiarité pourrait reposer sur la facilité de ... [more ▼]

La reconnaissance chez les patients amnésiques repose principalement sur le sentiment de familiarité. Plusieurs études indiquent que ce sentiment de familiarité pourrait reposer sur la facilité de traitement. Cependant, si les patients amnésiques utilisent normalement cette heuristique métacognitive est une question qui n’a pas encore été explorée de manière approfondie. Dans la présente étude, nous avons utilisé le paradigme de l'illusion de Jacoby et Whitehouse (1989) avec 8 patients atteints de troubles graves de la mémoire et 16 participants sains et appariés. La facilité de traitement a été induite lors du test de reconnaissance en présentant brièvement une amorce qui correspondait au mot devant être évalué. Les résultats préliminaires de cette étude ont révélé que la facilité de traitement induite par l’amorce augmentait les réponses de reconnaissance lorsque la phase d'étude et la phase de test étaient dans la même modalité sensorielle, mais non lorsque l'étude et le test étaient dans des modalités différentes. Les sujets sont donc capables de moduler leur utilisation de la facilité de traitement en tant qu’indice de mémoire en fonction de la non-diagnosticité perçue de cet indice. Cependant, cet effet de modalité semble limité aux participants sains. Les patients amnésiques quant à eux ne semble pas moduler leur utilisation de l'heuristique de fluence. Dans l'ensemble, ces résultats suggèrent que la facilité de traitement peut être utilisée comme un indice pour la reconnaissance dans l'amnésie. Cependant, cette utilisation est sujette à des changements métacognitifs. [less ▲]

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See detailL’impact de la réserve cognitive sur le fonctionnement exécutif au cours du vieillissement normal
Lesoinne, Alexia ULg; Simon, Jessica ULg; Gilsoul, Jessica ULg et al

Poster (2017, May 20)

Il existe une forte variabilité interindividuelle quant aux effets du vieillissement sur la cognition. Selon Stern (2009), les individus qui ont développé un haut niveau de réserve cognitive résisteraient ... [more ▼]

Il existe une forte variabilité interindividuelle quant aux effets du vieillissement sur la cognition. Selon Stern (2009), les individus qui ont développé un haut niveau de réserve cognitive résisteraient mieux aux effets du vieillissement. Afin de déterminer les facteurs de réserve cognitive qui expliquent le déclin exécutif dans le vieillissement, nous avons recruté 165 participants âgés de 59 à 81 ans. Ils ont effectué sept tâches évaluant le fonctionnement exécutif : des épreuves d’inhibition (Stroop et Incompatibilité de la TAP), de flexibilité (Flexibilité de la TAP, épreuve d’alternance arithmétique « plus-moins ») et de mise à jour (subtest Lettre-Chiffre de la MEM III, mise à jour de consonnes et tâche de 2-back). De plus, les participants ont complété différents questionnaires évaluant quatre facteurs de réserve cognitive (niveau d’études, parcours professionnel, activité physique et activités de loisir). Nous avons réalisé des analyses de régression linaire hiérarchique. Après avoir contrôlé les facteurs démographiques, nous avons observé que la réalisation d’au moins une activité culturelle au cours de la vie impactait positivement les capacités d’inhibition, alors que la mise à jour était impactée négativement par un trop grand nombre de loisirs domestiques. Lorsqu’on considère les loisirs actuellement pratiqués, nous observons que la réalisation d’au moins un loisir social a un impact positif sur la flexibilité alors que deux activités à caractère social sont nécessaires pour avoir un impact positif sur la mise à jour. En conclusion, nous observons un effet mitigé et différencié de la réserve cognitive sur le déclin exécutif. [less ▲]

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See detailRecollection versus familiarité dans le vieillissement normal et pathologique : Impact du format du test
Simon, Jessica ULg; Gilsoul, Jessica ULg; SALMON, Eric ULg et al

Poster (2017, May 19)

If familiarity is better preserved than recollection in aging and in the early stage of Alzheimer's disease (Koen & Yonelinas, 2014), the experimental conditions promoting its use should be beneficial to ... [more ▼]

If familiarity is better preserved than recollection in aging and in the early stage of Alzheimer's disease (Koen & Yonelinas, 2014), the experimental conditions promoting its use should be beneficial to these populations. One condition influencing the relative contribution of recollection and familiarity during recognition is the format of the test. The aim of this study was to investigate the impact of test format on recollection and familiarity in normal aging and in MCI in two tasks where the level of performance is equalized. Seventy young participants, 70 younger-old (55-69 years old), 69 older-old (70-85 years old), and 13 MCIs were presented with forced-choice and yes/no visual recognition memory tasks with the Remember/Know/ Guess paradigm. Young participants had better recognition memory performance than younger-old, who performed better than older-old and MCIs. Recollection and familiarity declined progressively in healthy aging. In MCI, recollection was more affected than familiarity, but patients demonstrated a more liberal use of familiarity. Finally, test format did not influence strongly the results. Young people used recollection more often in the forced-choice task compared to the yes/no task. [less ▲]

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See detailViolence psychologique dans les relations amoureuses – Quelle tolérance à la perpétration et à la victimisation ?
Courtain, Audrey ULg; Glowacz, Fabienne ULg

Poster (2017, May 19)

Les relations amoureuses des jeunes adultes peuvent être empreintes de diverses formes de violences (psychologique, physique ou sexuelle). La recherche considère généralement que la violence psychologique ... [more ▼]

Les relations amoureuses des jeunes adultes peuvent être empreintes de diverses formes de violences (psychologique, physique ou sexuelle). La recherche considère généralement que la violence psychologique est moins grave que les formes physique ou sexuelle. Or, elle ne peut pas être négligée. Notre objectif de faire un état des lieux des violences psychologiques que ces jeunes peuvent agir ou subir dans leurs relations amoureuses, et d’explorer dans quelle mesure ils ont des attitudes qui tolèrent (ou pas) ces violences. Méthodologie : Un questionnaire papier a été administré à un large échantillon composé d’étudiants (N>1000, 18-25 ans) en Belgique francophone. Ce questionnaire reprend deux outils : l’un traitant de la violence dans les relations amoureuses (« Conflict in Adolescent Dating Relationships Inventory », Wolfe et al., 2001) et l’autre traitant des attitudes relatives à ces violences («Attitudes Toward Dating Violence Scale », Price & Byers, 1999). Résultats : Après un descriptif des prévalences de violences psychologiques agies et subies, ainsi que des attitudes des participants, nous traiterons des liens entre les violences psychologiques et les attitudes afférentes, en termes de perpétration et de victimisation. Tout au long de nos analyses, les différences de genre seront considérées. Discussion : Ces résultats nous montrent comment les violences psychologiques et leurs attitudes afférentes sont liés, tant en termes de perpétration que de victimisation. S’inscrivant dans la continuité des recherches américaines, nos résultats encouragent l’élaboration de programmes de prévention et de sensibilisation auprès des jeunes adultes par un travail sur les attitudes. [less ▲]

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See detailTraiter l’alexithymie en Hôpital de Jour Psychiatrique : Identification des modulateurs favorisant une meilleure prise en charge
Nasello, Julian ULg; Servais, Catherine; Close, Mireille et al

Poster (2017, May 19)

L’alexithymie (i.e., incapacité à exprimer ses émotions par des mots) serait-elle sensible aux traitements psychothérapeutiques dispensés en Hôpital de Jour (HPJ) ? Quelles en seraient les variables ... [more ▼]

L’alexithymie (i.e., incapacité à exprimer ses émotions par des mots) serait-elle sensible aux traitements psychothérapeutiques dispensés en Hôpital de Jour (HPJ) ? Quelles en seraient les variables prédictives ? Notre recherche a porté sur 73 participants sélectionnés en HPJ et présentant des troubles de l’humeur. En comparant les scores d’entrée et de sortie, des réductions significatives ont été observées sur tous les aspects d’alexithymie. De plus, certaines variables impactant significativement sur l’alexithymie ont été mises en avant : variables démographiques (i.e., genre ; âge ; durée de séjour) ; médication ; variables du MMPI-2 ; support social perçu (PSS). Il apparait que le PSS ainsi que cinq variables mesurées par le MMPI-2 (e.g., les pratiques antisociales ou les attitudes négatives face au traitement) tendaient à réduire ou augmenter les niveaux d’alexithymie. Dès lors, ces résultats tendent à favoriser une conception plus flexible des traits de personnalité, à mettre en évidence le rôle fondamental de la régulation exogène des émotions et à fournir aux thérapeutes les variables à prendre en considération pour optimiser la prise en charge de l’alexithymie. [less ▲]

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See detailClinical pathway evaluation for left and sigmoid colectomy in abdominal surgery
Mattart, Laurine; Stevens, Marie; Magis, David ULg et al

Poster (2017, May 19)

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See detailExploration des processus de recollection et de familiarité chez des patients présentant une plainte mnésique : une étude longitudinale
Simon, Jessica ULg; Collette, Fabienne ULg; SALMON, Eric ULg et al

Poster (2017, May 19)

Recollection refers to recall of details about past events, and familiarity is a feeling of oldness. In this study, we tested how recollection and familiarity are affected in patients with memory ... [more ▼]

Recollection refers to recall of details about past events, and familiarity is a feeling of oldness. In this study, we tested how recollection and familiarity are affected in patients with memory complaints compared to normal aging. We recruited 23 healthy older participants, 9 patients with subjective memory impairment (SCI) and 23 patients with mild cognitive impairment (MCI). Participants performed one 2-alternative forced-choice and one Yes-No recognition memory task including pictures and words, followed by a short neuropsychological evaluation. Fifteen healthy participants and 23 patients (9 SCI and 14 MCI) took part in a neuropsychological follow-up after a mean delay of 21 months. At inclusion, MCI patients had poorer performance in recognition than the other groups, which did not differ. MCI patients had worse performance regarding familiarity and recollection indexes compared to healthy controls and SCI, who exhibit similar performance. There was no interaction between groups and format or material. During the follow-up evaluation, five MCI returned to a normal level of efficiency and were considered as SCI. Based on the French adaptation of the free and cued selective reminding test (RLRI-16), we calculated cognitive decline curves in our patients. We observed that recollection and familiarity indexes were explained by the decline curves calculated on the number of freely recalled items. So, recollection and familiarity were used less efficiently in MCI than SCI although both groups complained about their memory. [less ▲]

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See detailDes jeux de doigts pour renforcer les précurseurs des apprentissages scolaire
Dauvister, Estelle; Vossius, Line ULg; Rousselle, Laurence ULg

Poster (2017, May 19)

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See detailVieillissement non pathologique des fonctions exécutives : influence du polymorphisme nucléotidique val108/158met du gène COMT
Gilsoul, Jessica ULg; Manard, Marine ULg; Collette, Fabienne ULg

Poster (2017, May 19)

Introduction. Selon la Théorie des États-Duaux, les homozygotes Val sur le gène COMT possèderaient de meilleures capacités de flexibilité tandis que les individus Met/Met favoriseraient les capacités de ... [more ▼]

Introduction. Selon la Théorie des États-Duaux, les homozygotes Val sur le gène COMT possèderaient de meilleures capacités de flexibilité tandis que les individus Met/Met favoriseraient les capacités de stabilité. Ces effets génotypiques seraient amplifiés dans le vieillissement car la diminution des ressources cérébrales augmente l’influence des différences génétiques sur la cognition. Notre but est d’investiguer l’influence du polymorphisme nucléotidique COMTVal108/158Met sur les fonctions exécutives dans le vieillissement normal. Méthode. Trois fonctions exécutives ont été évaluées grâce à différentes tâches chez des participants jeunes (N=55) et âgés (N=45) portant l’un des génotypes du gène COMT (Val/Val, Val/Met, et Met/Met). Nous avons réalisé des tests t entre les deux groupes ainsi qu’une ANOVA 6 (Groupe : Jeunes-Met/Met, Jeunes-Val/Met, Jeunes -Val/Val, Âgés-Met/Met, Âgés-Val/Met, et Âgés-Val/Val) X 3 (Fonctionnement exécutif : Inhibition, Flexibilité, et Mise à jour) à mesures répétées avec le Fonctionnement exécutif comme facteur intra-sujet (p < ,05). Résultats. Jeunes et âgés différaient significativement sur les trois fonctions exécutives. Au sein des groupes jeunes et âgés, aucune différence significative n’a pu être mise en évidence entre les groupes génotypiques. De façon intéressante, le groupe des Âgés-Val/Val avait de plus faibles performances que le groupe des Jeunes-Val/Val en inhibition. Discussion. Comme attendu, nous avons trouvé un effet de l’âge sur toutes les fonctions exécutives. La différence entre les Jeunes-Val/Val et les Âgés-Val/Val en inhibition soutient l’idée d’une diminution avec l’avancée en âge des performances lorsqu’une composante de stabilité est requise par la tâche chez des individus possédant un génotype moins favorable pour cette composante. [less ▲]

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See detailLe fonctionnement exécutif dans le vieillissement normal : l’effet médiateur de la vitesse de traitement et du système attentionnel
Gilsoul, Jessica ULg; Simon, Jessica ULg; Collette, Fabienne ULg

Poster (2017, May 19)

Introduction. Le vieillissement normal est associé à une diminution d’efficacité des fonctions exécutives. Cependant, la source de ces difficultés pourrait résider dans certains facteurs « non exécutifs » ... [more ▼]

Introduction. Le vieillissement normal est associé à une diminution d’efficacité des fonctions exécutives. Cependant, la source de ces difficultés pourrait résider dans certains facteurs « non exécutifs ». Dès lors, cette étude a pour but de déterminer si la vitesse de traitement et les variables attentionnelles pourraient médier l’effet de l’âge sur le fonctionnement exécutif. Méthode. Des participants jeunes (N = 104) et âgés (N = 63) ont réalisé une batterie de 21 tâches exécutives (inhibition, flexibilité, mise à jour, et coordination de double tâches), attentionnelles (alerte phasique, attention sélective, et attention soutenue), et de vitesse de traitement. Des modèles de médiation avec la vitesse de traitement et le fonctionnement attentionnel pris séparément comme médiateurs ont été réalisés. Résultats. L’attention sélective médie significativement l’effet de l’âge sur la mise à jour [ΔR2 = 7%, p < ,001]. De plus, la vitesse de traitement médie significativement l’effet de l’âge sur la flexibilité [ΔR2 = 7%, p < ,001], la mise à jour [ΔR2 = 5%, p < ,001], et la coordination de double tâches [ΔR2 = 14%, p < ,001].Discussion. La médiation de l’effet de l’âge sur la plupart des fonctions exécutives par les mesures de vitesse est en accord avec la littérature montrant une grande influence d’un ralentissement de la vitesse de traitement sur la cognition. L’effet de l’âge sur l’inhibition ne semble médié par aucune des variables attentionnelles et de vitesse, ce qui est en accord avec l’hypothèse selon laquelle l’inhibition serait la première fonction cognitive à décliner avec l’avancée en âge (Zacks & Hasher,1988). [less ▲]

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See detailStructural and Magnetic Properties of Nanosized strontium Hexaferrite Powders: Experimental and theoretical investigation
Abraime, Brahim; Ait Tamerd, Mohamed; Mahmoud, Abdelfattah ULg et al

Poster (2017, May 18)

Strontium M-type hexagonal ferrites were synthesized at different calcination temperatures (800 °C, 1000°C and 1100 °C) using sol-gel autocombustion method. Thermogravimetric analysis (TGA), X-ray ... [more ▼]

Strontium M-type hexagonal ferrites were synthesized at different calcination temperatures (800 °C, 1000°C and 1100 °C) using sol-gel autocombustion method. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Mössbauer spectroscopy (MS) and superconducting quantum interference device magnetometer (SQUID) techniques were used to characterize crystal structure, phase composition, morphology and magnetic properties. TGA gives T=800 °C as beginning of suitable calcination. Hexaferrite structure of single phase is obtained according to XRD results for all samples with crystallite size between 28 nm and 35 nm. SEM images show the growth of grain size with increasing of annealing temperature. (BH)max is calculated based on SQUID results and shows an enhancement between T=800°C and T= 1000°C of 25%. The magnetic properties observed at low temperature are explained and confirmed by ab-initio calculations. [less ▲]

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See detailMécanismes de vieillissement des anodes à base de FeSn2 pour batteries Li-ion
Chamas, Mohamad; Mahmoud, Abdelfattah ULg; Tang, junlei et al

Poster (2017, May 18)

Les intermétalliques d’étain ont été proposés comme matériaux d’anode pour batteries Li-ion à forte densité d’énergie car leur capacité spécifique est bien supérieure à celle des anodes commerciales à ... [more ▼]

Les intermétalliques d’étain ont été proposés comme matériaux d’anode pour batteries Li-ion à forte densité d’énergie car leur capacité spécifique est bien supérieure à celle des anodes commerciales à base de carbone. Le mécanisme électrochimique est basé sur la transformation irréversible de FeSn2 en un composite formé de nanoparticules de fer et de Li3.5Sn lors de la première lithiation, puis de réactions réversibles modifiant la composition de Li3.5Sn, les particules de fer assurant la dispersion de ces particules à base d’étain [1]. Cependant, nous avons observé que l’électrode lithiée était instable dans le temps conduisant à l’autodécharge progressive de la batterie [2]. Ce phénomène de vieillissement a été caractérisé par spectrométrie Mössbauer du 57Fe et de 119Sn, par spectroscopie d’impédance et par mesures magnétiques (Figure 1). On montre que le composite Fe/Li3.5Sn se délithie progressivement au cours du temps conduisant à un composite faiblement lithié Fe/LixSn avec x<1. Les nanoparticules de fer sont stables et ne réagissent pas avec LixSn. Les atomes de lithium libérés réagissent avec l’électrolyte et modifient la morphologie de la couche SEI (Surface Electrolyte Interphase) située à la surface des particules LixSn du composite.[1] M. Chamas, M. T. Sougrati, C. Reibel, P.E. Lippens, Chem. Mater. 25, 2410 (2015). [2] M. Chamas, A. Mahmoud, J. Tang, S. Panero, M. T. Sougrati, P. E. Lippens, J. Phys Chem. C 121, 217 (2017). [less ▲]

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See detailModulation of NMDA receptor mediated excitatory synaptic currents in dopamine neurons of the substantia nigra
Destreel, Geoffrey ULg; Seutin, Vincent ULg; Engel, Dominique ULg

Poster (2017, May 17)

Dopamine (DA) neurons of the substantia nigra pars compacta (SNc) exhibit two main firing modes, spontaneous single action potential (AP) firing and bursting. The amount of DA released by these neurons in ... [more ▼]

Dopamine (DA) neurons of the substantia nigra pars compacta (SNc) exhibit two main firing modes, spontaneous single action potential (AP) firing and bursting. The amount of DA released by these neurons in target areas depends on the presynaptic AP firing pattern and is essential to modulate several aspects of behavior such as the control of movement. Bursting activity is mediated by excitatory afferents and specifically by the activation of NMDA receptors (NMDARs). However, the level of activation of NMDARs at these synapses during spontaneous synaptic activity is unknown. We assessed the occupancy of the glycine binding sites of the NMDAR by testing the effects of coagonists and by blocking the uptake of glycine on spontaneous excitatory postsynaptic currents (sEPSCs) in DA neurons of the SNc. Parasagittal midbrain slices (300 – 350 µm thickness) were cut from the brains 16- to 26- days old Wistar rats using a vibratome. Whole-cell recordings were made using warm (~35C°) standard artificial cerebrospinal fluid. sEPSCs were pharmacologically isolated and recorded at +40 and -70 mV. A large NMDAR-sEPSC component was present at +40 mV as revealed by the application of 50 µM D-AP5 (n=8, P < 0.001). At -70 mV, D-AP5 had no effect on the EPSC, as expected (n=7, P = 0.52). The mean amplitude of the average NMDAR sEPSC measured at +40 mV increased significantly from 8.6 ± 0.8 pA in control conditions to 10.9 ± 1.0 pA during bath application of 300 μM glycine (n=10, P < 0.001). We also investigated the effect of D-serine, the other coagonist at the NMDAR glycine site. The mean NMDAR EPSC amplitude measured at +40 mV showed a tendency toward larger values, from 6.8 ± 0.8 pA in control conditions to 8.8 ± 1.1 pA in the presence of 100 µM D-serine (n=4). Blockade of the glycine transporter-1 (GlyT1) significantly increased the mean amplitude of NMDAR sEPSCs measured at +40 mV from 7.1 ± 0.5 pA in control conditions to 10.5 ± 0.8 pA in the presence of 5 μM NFPS (n=8, P < 0.001). At -70 mV, NFPS had no effect on the AMPAR-sEPSC component, as expected (n=8, P = 0.23). In conclusion, our results indicate that the NMDAR glycine sites are not saturated by glycine and D-serine during sEPSCs in control conditions. [less ▲]

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See detailUse of a bio-based binder in the building sector
Gerbinet, Saïcha ULg; Briard, Vincent; Pigeolet, Jean-Pierre et al

Poster (2017, May 15)

A binder is a material or a substance that holds materials together, like a glue. In the building sector, binders have several applications: they can be used in producing wood panels such as MDF to paste ... [more ▼]

A binder is a material or a substance that holds materials together, like a glue. In the building sector, binders have several applications: they can be used in producing wood panels such as MDF to paste together the wood particles and give the panels their stabil-ity. They are also used in insulation materials, such as glass wool or stone wool to bind the fibers together. Traditional binders are mostly fossil-based (phenol-formaldehyde, urea-formaldehyde, etc.), and previous Life Cycle Assessments (LCA) [1-3] show that these binders, even if they are a minor component on a mass basis, can have a major contribution to the environmental impact of the material, especially in wood panels. In addition, the use of these binders has raised some sanitary questions, especially con-cerning indoor air quality. Therefore alternative binders are being investigated, namely bio-based binders. In this presentation, we focus on the ECOSE binder, developed by Knauf Insulation, a global building insulation manufacturer. It has the particularity of being based on plant starch and it is currently used in glass wool products, while other applications are being developed. We underline that using biomass as raw materials instead of fossil-based ma-terials could have several benefits on the environment, especially fossil resources deple-tion and CO2 emissions, but that this is not necessarily the case for all environmental as-pects, for instance land use, even if only the direct land use is included in this study. The presentation will first underline the differences in term of environmental impact be-tween the traditional binder and ECOSE applied in glass mineral wool. Indeed, a compar-ison on a mass basis is not totally relevant: two binders can have different application conditions; therefore, we can only compare them at the application level. But the main focus of the presentation will be on the hypothesis made in the modeling of the biomass part and their influence on the results. For example, the influence of the use of bio-based raw materials instead of traditional ones will be studied, but also the influence of the dis-tance between farm and factory where the starch is produced. The use of local data will be compared with the use of databases. All these results will highlight the difficulties in studying bio-based products and to compare them with fossil-based ones. The use of LCA and a complete analysis of the results are essential to better understand the chal-lenges related to binder technology modification. ________________________________________ 1. Rivela, B., et al., Life cycle inventory of particleboard: A case study in the wood sector. International Journal of Life Cycle Assessment, 2006. 11(2): p. 106-113. 2. Wilson, J.B., Particleboard: A Life-Cycle Inventory of Manufacturing Panels from Resource through Product, in CORRIM: Phase II Final Report. 2008, Department of Wood Science and Engineering, Oregon State University. 3. Silva, D.A.L., et al., Environmental performance assessment of the melamine-urea-formaldehy (MUF) resin manufacture: a case study in Brazil. Journal of Cleaner Production, 2015. 96. [less ▲]

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See detailBelgian speleothem records Holocene cold events?
Allan, Mohammed ULg; Deliège, Adrien ULg; Nicolay, Samuel ULg et al

Poster (2017, May 12)

Speleothem is now regarded as valuable archive of climatic conditions on the continents, offering a number of advantages relative to other continental climate proxy recorders such as lake sediments and ... [more ▼]

Speleothem is now regarded as valuable archive of climatic conditions on the continents, offering a number of advantages relative to other continental climate proxy recorders such as lake sediments and peat cores. High spatial resolution measurements of Mg, Al, Sr, Ba were realized by using laser-ablation inductively coupled plasma mass spectrometry in the Belgian Pere Noel cave. A stalagmite from the Pere Noel (PN) cave representing 12000 years dated by U/Th method. Trace element variations in speleothem are a reflection of hydrochemical conditions. These changes were interpreted as indications of changes in climate in the Han-sur-Lesse region. The similar patterns found in δ 18O, δ 13C and chemical composition along the Pere Noel stalagmite suggests that trace elements in speleothems have the potential to provide high resolution insights into palaeoclimatic variability during the Holocene. A deeper analysis reveals several periods of significant rapid climate change during the Holocene (at 10.7-9.2 ka, 8.2-7.9 ka, 7.2-6.2 ka, 4.8-4.5 ka, and 3-2.4 ka BP), which are similar to the cold events detected from different natural paleoclimate archivers. A comparison between the geochemical analysis of Père Noël speleothem and solar activity (sunspot number) reveals a significant correlation. Spectral analysis methods reveal common solar periodicities (Gleissberg cycle, de Vries cycle, unnamed 500 year, Eddy cycles, and Hallstatt cycle). The geochemical analyses have the potential to prove that PN speleothem is sensitive to changes in solar activity on centennial and millennial timescales during the Holocene. [less ▲]

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See detailStudy of the regulation of the operon ftsW-psr-pbp5 in Enterococcus hirae
Raymackers, Alice ULg; Maréchal, Maxime; Verlaine, Olivier ULg et al

Poster (2017, May 11)

Detailed reference viewed: 14 (3 ULg)
See detailMAGED2 function as cell cycle regulator after a genotoxic stress
Trussart, Charlotte ULg; Pirlot, Céline; Piette, Jacques ULg et al

Poster (2017, May 11)

Detailed reference viewed: 14 (1 ULg)
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See detailToRQuEMaDA: Tool for retrieving queried eubacteria, metadata and dereplicating assemblie
Léonard, Raphaël ULg; Sirjacobs, Damien ULg; Sauvage, Eric ULg et al

Poster (2017, May 11)

The fast-growing number of available prokaryotic genomes, along with their uneven taxonomic distribution, is a problem when trying to assemble broadly sampled genome sets for phylogenomics and comparative ... [more ▼]

The fast-growing number of available prokaryotic genomes, along with their uneven taxonomic distribution, is a problem when trying to assemble broadly sampled genome sets for phylogenomics and comparative genomics. Indeed, most of the new genomes belong to the same subset of hyper-sampled phyla, such as Proteobacteria and Firmicutes, or even to single species, such as Escherichia coli (>3000 genomes as of March 2017), while the continuous flow of newly discovered phyla prompts for regular updates of in-house databases. This situation makes it difficult to maintain sets of representative genomes combining lesser known phyla, for which only few species are available, and sound subsets of highly abundant phyla. An automated method is required but none are publicly available. In this work, the kmer composition of DNA sequences, in conjunction with quality metrics for publicly available assemblies, was used to develop an automated approach for selecting a high-quality subset of representative genomes without redundancy by using our hybrid divide-and-conquer / greedy clustering method. [less ▲]

Detailed reference viewed: 13 (3 ULg)
Peer Reviewed
See detailCrosstalk between VEGF and BMP9 pathway. Implications in HHT disease
Pollenus, Thomas ULg

Poster (2017, May 11)

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Peer Reviewed
See detailLacustrine clay mineral assemblages as a proxy for land-use and climate changes over the last 4 kyr: The Amik Lake
El Ouahabi, Meriam ULg; Hubert, Aurelia ULg; Allan, Mohammed ULg et al

Poster (2017, May 10)

Lake sediments are sensitive to landscape changes and most of these changes seem to be modulated by land-use (anthropogenic factors) coupled to palaeoenvironmental/palaeoclimatic changes. In its detrital ... [more ▼]

Lake sediments are sensitive to landscape changes and most of these changes seem to be modulated by land-use (anthropogenic factors) coupled to palaeoenvironmental/palaeoclimatic changes. In its detrital fraction, the lacustrine sediments record the history of soil erosion within its catchment via the inputs of clays and others detrital products. Within a Mediterranean context, the study investigates the upper sediments infilling the central part of the Amik basin in southern Turkey. This tectonic basin was occupied and exploited by modern human at least since 6000-7000 BC. We focus on the clay mineralogy (x-ray diffraction on oriented aggregates) and magnetic susceptibility measurements (Bartington) of the sedimentary record in the area over the last 4000 years, to assess environmental changes in relation with the different land uses and/or weathering during the successive Bronze, Iron, Roman, Islamic/Ottoman and Modern civilizations. The clay fraction of Amik Lake sediments comprises smectite, kaolinite, illite, chlorite and chlorite/smectite mixed layers that are the inherited clay phases. A relative change in abundance and crystallinity and chemistry of illite attests that environmental conditions evolved in the Amik Plain from the Bronze to Modern Age in relation with climates and/or land-use changes. The history of the Amik Lake reveals different soil erosion episode. The most intense erosion phase occurred during the Bronze/Iron Ages as indicated by the clay and magnetic susceptibility proxies. The Roman period was an exceptional period with soil erosion products arriving from the watershed, probably due the water channelization. A reduction of soil erosion occurred during the post Roman period until nowadays. Significant pedogenesis transformations are evidenced, especially during the Islamic/Ottoman periods suggesting intense chemical weathering conditions related to climate change. [less ▲]

Detailed reference viewed: 49 (13 ULg)
Peer Reviewed
See detailSmart-shoes self-powered by walking
Colson, Gérald ULg; Laurent, Philippe ULg; Bellier, Pierre ULg et al

Poster (2017, May 10)

Nowadays, electronic devices are more and more compact and can be integrated in nearly every object. One of the remaining challenges is to provide smarter ways to power those electronic devices. Because ... [more ▼]

Nowadays, electronic devices are more and more compact and can be integrated in nearly every object. One of the remaining challenges is to provide smarter ways to power those electronic devices. Because of the small amount of energy needed by the latest ultra-low power systems, energy harvesting from the environment becomes a viable solution to power them. In this work, we present the integration of an electronic device and an electrodynamic energy harvester (EH) in a shoe. The electronic device measures the acceleration along one axis at a sampling rate of 30 Hz and sends the data every second using a wireless link. The data are then collected by a gateway and processed to count the number of steps, calculate the contact time and the flying time of the foot. To perform this function, the device requires an average power of 951 μW which is provided by the EH. [less ▲]

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See detailInnovative silage additives to reduce proteolysis in the silo
Herremans, Sophie ULg; Decruyenaere, Virginie; Beckers, Yves ULg et al

Poster (2017, May 10)

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See detailGlucose production: influence of the datasets and of the long term emissions on LCA results
Gerbinet, Saïcha ULg; Belboom, Sandra ULg; Léonard, Angélique ULg

Poster (2017, May 08)

The aim of this study is to have a good understanding of the environmental impact of glucose production. Glucose is generally produced from corn or wheat. Since agricultural processes are known to be ... [more ▼]

The aim of this study is to have a good understanding of the environmental impact of glucose production. Glucose is generally produced from corn or wheat. Since agricultural processes are known to be difficult to evaluate by LCA, the results obtained with two different LCA databases, Gabi and EcoInvent, are compared in this work. The production of glucose from raw materials can be divided in two steps: the agricultural step allowing the cereal production, and the conversion step including the extraction of the starch from the plant and its hydrolysis into glucose. Preliminary results underline the high impact of the agricultural step, so a special attention has been paid to these data. Specific Belgian data collected by the Walloon Agricultural Research Centre (CRA-W) (2014) [1] have been used as primary data (yield, amount of fertilizers, etc.), either using EcoInvent or Gabi datasets background data to model fertilizers, diesel consumption, etc. A third model was built using only data available in Ecoinvent for corn and wheat cultures. For the conversion steps, literature data have been used along with some industrial data. Based on these multiple sources, it is possible to compare the LCA results for the production of 1 kg of glucose for three different cases. The results underlined that the differences between the two databases are smaller than the differences between specific data (Belgium data) or non-specific data (Ecoinvent) for the agricultural steps. Nevertheless, in some impact categories, the differences between the two databases remain high. The presentation will underline where these differences are coming from. This leads to also analyze the differences between background data such as energy generation or fertilizer production. Moreover, special attention has been put on the influence of long-term emissions, in the Ecoinvent database. As these emissions have a large influence in some impact categories, we have to clarify if we should include them or not in view of comparison with GaBi database. Moreover, the Ecoinvent model and the GaBi models have been realized in two different software (Simapro and GaBi, respectively), therefore, some checks have been performed to see if some differences can be induced by the software. In conclusion, this presentation will underline which is the sensibility of the results to parameters not controlled by the LCA practitioner, such as the datasets hypotheses, the software differences, etc. 1. Walloon Agricultural Research Centre (CRA-W), ALT4CER project. 2014. [less ▲]

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See detailMONitOring des flux de POLluants dans les Eaux Souterraines
Jamin, Pierre ULg; Dassargues, Alain ULg; Brouyère, Serge ULg

Poster (2017, May 05)

Contaminated aquifers management is currently based on the evaluation of pollutant concentration in the groundwater. This approach is necessary but totally insufficient to evaluate the risk posed by the ... [more ▼]

Contaminated aquifers management is currently based on the evaluation of pollutant concentration in the groundwater. This approach is necessary but totally insufficient to evaluate the risk posed by the contamination to potential receptors. Since the risk is due to the pollutant that are actually moving, and might reach a receptor, this concentration measurement should be combined to a measurement of the groundwater flow velocity (i.e. the driving force of contaminant migration in aquifers), to quantify the contaminant mass flux at which the receptor is exposed. We propose a new point dilution technique able to measure accurately the groundwater flux and to monitor continuously its changes with time. [less ▲]

Detailed reference viewed: 24 (3 ULg)
See detailQuantifying coral colony morphology to assess their roles in ecosystem processes
Chen, Qi; Yang, Emma; Sturaro, Nicolas ULg et al

Poster (2017, May 04)

Colony morphology is among the best predictors of the scleractinian coral’s function in the reef ecosystem. However, morphological traits are categorical and to convert this information into a ... [more ▼]

Colony morphology is among the best predictors of the scleractinian coral’s function in the reef ecosystem. However, morphological traits are categorical and to convert this information into a quantitative value remains a real challenge to quantify the influence of this parameter on ecosystem processes. Recently, the ratio between colony mass and surface area (CMA) has been proposed to represent a suitable proxy of species morphologies and their growth. Hypothetically, CMA could be used to assess a broad range of biological, ecological, and evolutionary processes in coral reef ecosystem. Here, we propose to test CMA as a predictor of coral morphology and focus on the intraspecific variation of this parameter. We used historical coral collection from the Museum of Zoology (National Taiwan University) and our own specimens collected from contrasting environments to establish a database of coral models using a high-resolution David 3D scanner. From these models, we extracted surface area and volume of the coral colonies. Colony mass was measured on a Mark S Bel balance. CMA was compared for its power in predicting species morphology with other traits such as skeleton density. Eventually, we tested the use of CMA at an intraspecific level to detect plasticity in growth rate. Our 3D models are available online (http://www.dipintothereef.com/corals.html) and constitute a valuable resource for estimating the roles of corals in the ecosystem. [less ▲]

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See detailReinforced poly(hydroxyurethane) coatings and high performance adhesive
Panchireddy, Satyannarayana ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

Poster (2017, May 04)

Polyurethane (PU) is one of the most widely used polymeric materials and largely valorised in coating applications as paints or as adhesives. Because toxicity issues of isocyanates and changes in the ... [more ▼]

Polyurethane (PU) is one of the most widely used polymeric materials and largely valorised in coating applications as paints or as adhesives. Because toxicity issues of isocyanates and changes in the environmental and REACH regulations, there is a need today to develop new greener and safer alternatives to produce PU. One of the most promising way relies on the synthesis of polyurethane by a non-isocyanate route (NIPU) by copolymerization between a bicyclic carbonate monomers and a diamine. This study reports on the synthesis of new sustainable NIPU coatings for Al anti-corrosion protection and for metal adhesion. In a first step, (bio- and) CO2-sourced cyclic carbonates will be synthesized by coupling of multifunctional epoxides with CO2 using a new efficient bicomponent organocatalyst. In a second step, various cyclic carbonates/amines formulations were developed and cured in presence of fillers to produce reinforced NIPUs thermosets which anti-corrosion and adhesive properties are evaluated and benchmarked with existing formulations. Some formulations present outstanding adhesions to various substrates. [less ▲]

Detailed reference viewed: 28 (4 ULg)
See detailSynthesis of well-defined polyvinylamine-containing copolymers via organometallic-mediated radical polymerization
Stiernet, Pierre ULg; Demarteau, Jérémy ULg; Jérôme, Christine ULg et al

Poster (2017, May 04)

Polyvinylamine (PVAm) is a useful polymer involved in a large range of applications including paper coating, surface engineering, membrane separation, etc. It is commonly produced via free radical ... [more ▼]

Polyvinylamine (PVAm) is a useful polymer involved in a large range of applications including paper coating, surface engineering, membrane separation, etc. It is commonly produced via free radical polymerization of N-vinylformamide (NVF) or N-vinylacetamide (NVA) followed by hydrolysis of the pendent amides of the resulting polymers. Due to the lack of stabilizing group on the double bond of N-vinylamides, the controlled radical polymerization of these monomers remained a challenge for a long time, preventing the preparation of well-defined PVAms. Recently, our group reported the controlled polymerization of NVA via reversible deactivation of the growing radical chains with cobalt complexes. Moreover, the use of well-defined PVAms as efficient carriers for gene transfection was demonstrated. This communication aims at reporting the synthesis of novel well-defined polyvinylamine-based copolymers. First, we explored the organometallic-mediated radical copolymerization of NVA and vinyl acetate. The optimized polymerization conditions and the comonomer reactivity ratios will be presented. Further conversion of the pendent amides and esters moieties into amino and hydroxy groups, respectively, was also considered for the preparation of unprecedented hydrophilic polyvinylamine-based copolymers. [less ▲]

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See detailPhoto-crosslinkable hydrogel for guided periodontal tissue regeneration
Chichiricco, Pauline Marie ULg; Riva, Raphaël ULg; Thomassin, Jean-Michel ULg et al

Poster (2017, May 04)

Periodontitis is an inflammatory disease resulting from the presence of oral bacteria biofilm in periodontal tissue, which destroys the tooth-supporting attachment apparatus. Untreated inflammation can ... [more ▼]

Periodontitis is an inflammatory disease resulting from the presence of oral bacteria biofilm in periodontal tissue, which destroys the tooth-supporting attachment apparatus. Untreated inflammation can spread to the gum tissue and lead, ultimately, to the loosening of the supporting tooth bone, with the risk that the tooth eventually falls. Guided Tissue Regeneration is a technique based on the application of a barrier membrane designed to prevent colonization of the wound space by epithelial cells from soft tissues. Indeed, these cells, characterized by a faster migration and proliferation rate compared to bone and periodontal ligament cells, could interfere with the regeneration process. In previously work Struillou et al. demonstrated the benefit effect of silated hydroxypropylmethylcellulose (Si HMPC)-based hydrogel can act as an efficient physical barrier in periodontal defect. Typically, this material is able to form a 3D network through the condensation of silanoate groups at physiological pH. However, a decrease of gelation time is necessary to assure the stability in peripheral part of the wound. In this project, we developed an injectable photo-crosslinkable membrane based on methacrylated carboxymethyl chitosan (CMCs) and Si HPMC that can be applied as a viscous solution and cured in situ in presence of a photoinitiator system made of riboflavin and triethanolamine. A visible light lamp (λ 420-480 nm), already used in dentistry, was preferred over a UV lamp. The addition of methacrylated polymer increase the stability of the material and increase the mass loss, in order to improve the bioresorption of the membrane. The chemical grafting of methacrylated carboxymethyl chitosan was characterized by 1H NMR and Infrared Spectroscopy. The gel point of the solution was determined by rheology and remained compatible with a clinical application. Moreover, the biocompatibility of this biomaterials was tested using murine cells using two assay: Neutral Red assay and MTT Cell Proliferation Assay. The in vitro tests validate the chemical synthesis in a biological point of view. The irradiation on cells and the direct contact with hydrogel doesn’t have an impact on cells viability. The capability of this material to act as a physical barrier was also evaluated using human gingival fibroblast. The cells were isolated from human gum explant before being put in contact with the hydrogel. After four days of contact no cells invasion was observed in the hydrogel using confocal microscopy. These preliminary results are quite promising for the development of novel injectable systems for Guided Periodontal Regeneration. In the future work, in vivo assays will be performed in Periodontal defect in a canine model. [less ▲]

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See detailDesign of polyphosphoester coplymers as scaffolds for tissue engineering applications
Shah, Urmil ULg; Ergül, Zeynep ULg; Jérôme, Christine ULg

Poster (2017, May 04)

Polymers with repeating phosphoester linkages in the backbone are biodegradable and emerged as a promising class of novel biomaterials. In contrast to polyesters, the pentavalency of the phosphorus atom ... [more ▼]

Polymers with repeating phosphoester linkages in the backbone are biodegradable and emerged as a promising class of novel biomaterials. In contrast to polyesters, the pentavalency of the phosphorus atom offers a large diversity of structures and as a consequence a wide range of properties for these materials. This study aims at taking profit of this easy functionalization to synthesize a series of degradable polymers of precisely tailored properties especially elasticity, hydrophilicity and functionality. We aim at developing a set of degradable materials in which only elasticity is varied keeping unchanged other parameters such as hydrophilicity, which remains quite a challenge. For that purpose, we have synthesized by organocatalyzed ring-opening polymerization,random di- and terpolymers between various cyclic phosphoesters bearing a short side-chain (hydrophilic), a longer side-chain (hydrophobic) and an unsaturated side-chain (butenyl)able to cross-link under UV irradiation. Playing on the composition of these copolymers, the cross-linking density and the hydrophilicity can be tuned quite independently. In the future, these materials will be used as model scaffolds to study the growth and differentiation of stem cells. [less ▲]

Detailed reference viewed: 30 (5 ULg)
See detailHow to exploit bio- and CO2-based isocyanates-free polyurethanes for environmental and biomedical applications?
Gennen, Sandro ULg; Grignard, Bruno ULg; Alves, Margot et al

Poster (2017, May 04)

Polyurethane (PU) is one of the most important family of polymers that is largely used in coatings, foams, elastomers, sealants/adhesives in the building, automotive, household and biomedical sectors ... [more ▼]

Polyurethane (PU) is one of the most important family of polymers that is largely used in coatings, foams, elastomers, sealants/adhesives in the building, automotive, household and biomedical sectors. Classically, PU is produced by a step-growth polymerization between di- or polyols and di- or polyisocyanates. However, isocyanates are toxic and produced from even more toxic phosgene. To avoid the use of isocyanates, different synthetic alternatives for PUs have been developed. One of the most studied approaches relies on the step-growth polymerization between di- or polyamines and CO2-sourced di- or polycyclic carbonates, affording poly(β-hydroxyurethane)s (PHUs) that showed improved thermal, chemical and mechanical properties compared to conventional PUs. In this study, we would like to show how PHUs can be exploited to design (bio- and) CO2-based foams for thermal insulation as well as novel reinforced hydrogels for potential biomedical applications. First, we developed a highly efficient binary organocatalyst for the fast and selective synthesis of cyclic carbonates under very mild conditions from CO2 and various epoxides, including bio-based ones. Secondly, these cyclic carbonates were valorised as monomers for the preparation of foams and hydrogels based on PHUs. In this poster, we will describe the preparation and characterization of these PHU foams and hydrogels, and highlight their huge potential as thermal insulating materials (PHU foams) or as biomaterials for shock absorption properties (PHU hydrogels). [less ▲]

Detailed reference viewed: 26 (1 ULg)
See detailSimple, cheap but highly efficient organo catalysts for the fixation of CO2 on propargylic alcohols
Ngassam Tounzoua, Charlene Gabriela ULg; Gilbert, Bernard ULg; Detrembleur, Christophe ULg et al

Poster (2017, May 04)

In the last years, many efforts have been devoted to the valorisation of CO2 as an abundant and renewable C1 building block for cyclic carbonate synthesis. Many synthetic routes have been proposed to ... [more ▼]

In the last years, many efforts have been devoted to the valorisation of CO2 as an abundant and renewable C1 building block for cyclic carbonate synthesis. Many synthetic routes have been proposed to convert CO2 into five or six-membered cyclic carbonates finding applications as green solvent, electrolytes for Li-ion batteries, intermediates for organic synthesis, monomers for the production of polycarbonates or isocyanate-free synthesis of poly(hydroxyrethane)s, etc. Although the 100% atom economy synthesis of 5-membered cyclic carbonates from CO2 and epoxides/oxetanes has been widely reported in the literature, the carboxylative coupling of CO2 with alkynols remains unexplored. Transition metal-based complexes, organic bases (guanidine, amidine, phosphine), N-heterocyclic carbenes or olefins, and K2CO3 have been proposed as catalysts. However they generally present sufficient activity at high pressure and/or temperature or require a high catalyst loading. Additionally some of them are toxic and/or sensitive to hydrolysis or oxidation. In this work, we designed novel, cheap, easily customizable and highly efficient organocatalysts for the synthesis of cyclic α-methylene carbonates from CO2 and alkynols. Kinetics of the CO2/alkynol coupling reaction were followed by Raman spectroscopy with organocatalysts of different structures, and the best candidate was identified. The main parameters that influenced the system reactivity and selectivity have been identified and will be presented in this poster. [less ▲]

Detailed reference viewed: 20 (4 ULg)
See detailAll poly(ionic) liquid-based block copolymers incorporating fluorinated and triethyleneglycol units: direct synthesis in water and investigation as single-ion conductive solids
Ouhib, Farid ULg; Cordella, Daniela; Aqil, Abdelhafid ULg et al

Poster (2017, May 04)

Poly(ionic liquid)s (PILs) have attracted a considerable attention as innovative single-ion solid polyelectrolytes (SPEs) in substitution to the more conventional electrolytes for a variety of ... [more ▼]

Poly(ionic liquid)s (PILs) have attracted a considerable attention as innovative single-ion solid polyelectrolytes (SPEs) in substitution to the more conventional electrolytes for a variety of electrochemical devices. Imidazolium-based PILs are amongst the most investigated, because they are easy to synthesize and some of them have shown a good combination between high ionic conductivity, wide chemical and electrochemical stability, and good mechanical properties. Herein, we report the precise synthesis, characterization, and use as single-ion SPE of a novel double PIL-based amphiphilic diblock copolymer (BCP), i.e. where all monomer units are of N-vinyl-imidazolium-type, with triethylene glycol pendant groups in the first block, and a statistical distribution of N-vinyl-3-ethyl- and N-vinyl-3-perfluorooctyl-imidazolium bromides in the second block. BCP synthesis is achieved directly in water by a one-pot process, following the principle of the cobalt-mediated radical polymerization-induced self-assembly (CMR-PISA). A subsequent anion exchange reaction substituting bis(trifluoromethylsulfonyl)imide (Tf2N-) for bromide (Br-) counter-anions leads to the targeted PIL BCPs with two different lengths of the first block. They demonstrate ionic conductivity σDC = 1-3 10-7 S cm-1, as determined by broadband dielectric spectroscopy at 30 °C (under anhydrous conditions), and form free standing films with mechanical properties suited for SPE applications with Young’s modulus of 3.8 MPa and elongation at break of 250 % as determined by stress/strain experiments. [less ▲]

Detailed reference viewed: 40 (2 ULg)
See detailThiol-ene reaction: an efficient tool to design polyphosphoester-based drug delivery systems
Riva, Raphaël ULg; Vanslambrouck, Stéphanie; Ergül, Zeynep ULg et al

Poster (2017, May 04)

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromolecules, polyphosphoesters (PPE) are appealing polymers for biomedical applications. In contrast to ... [more ▼]

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromolecules, polyphosphoesters (PPE) are appealing polymers for biomedical applications. In contrast to polyesters, PPE properties and functionality are easily tuned via the chemical nature of the lateral chains. To enhance the drug loading capacity of PPE-based micelles used as carriers for the delivery of poorly soluble drugs, an efficient strategy to increase the lipophilicity of the PPE block of polyethylene oxide (PEO)-b-PPE amphiphilic copolymers has been investigated. A PEO-b-PPE copolymer bearing pendant vinyl groups along the PPE block was synthesized and then modified by thiol-ene click reaction with thiols bearing either a long linear alkyl chain (dodecyl) or a tocopherol moiety. Ketoconazole was used as model for hydrophobic drugs. Comparison of the loading contents and release profiles with PEO-b-PPE bearing shorter pendant groups is presented evidencing the key role of the structure of the pendant group on the PPE backbone. Finally, the low cytotoxicity of these novel PEO-b-PPE copolymers was also demonstrated. The tocopherol derivative was evidenced as particularly promising for drug delivery systems. [less ▲]

Detailed reference viewed: 26 (2 ULg)
See detailSynthesis of cross-linked poly(HEMA) microparticles in supercritical carbon dioxide for sustained delivery
Caprasse, Jérémie ULg; Parilti, Rahmet ULg; Riva, Raphaël ULg et al

Poster (2017, May 04)

Microgels are micro-sized polymer networks able to swell or shrink depending on the environment. They find applications in many fields such as for environmental purpose or especially in the biomedical ... [more ▼]

Microgels are micro-sized polymer networks able to swell or shrink depending on the environment. They find applications in many fields such as for environmental purpose or especially in the biomedical field for tissue engineering or controlled drug-delivery applications. Indeed, the use of microgels allows a controlled and sustained release of an encapsulated active ingredient (AI), avoiding Burst release. This work aims at reporting on the solvent-free synthesis of well-defined hydrogel microparticles according to a free radical dispersion polymerization of hydroxyethyl methacrylate (HEMA) in supercritical carbon dioxide (scCO2) which confers environmentally benign features to the process2. For that purpose, a dedicated polymer surfactant has been designed by RAFT polymerization, i.e. poly(ethylene oxide-b-heptadecafluorodecyl acrylate) diblock copolymer with a photocleavable group at the junction of both blocks and used as stabilizer for the HEMA dispersion polymerization in scCO2. The synthesis conditions (stabilizer concentration, temperature and CO2 pressure,…) adapted for the in situ encapsulation of an active ingredient have been studied. Then, the photocleavage of the fluorinated block of the polymer stabilizer allows the further swelling of the polyHEMA particles in water and the sustained release of the encapsulated active ingredient through the microgels. This eco-friendly process allowing the formation of well-defined hydrogel particles, showing a sustain release of their content is quite promising for a high scale microparticles production. Microgels are micro-sized polymer networks able to swell or shrink depending on the environment. They find applications in many fields such as for environmental purpose or especially in the biomedical field for tissue engineering or controlled drug-delivery applications. Indeed, the use of microgels allows a controlled and sustained release of an encapsulated active ingredient (AI), avoiding Burst release. [less ▲]

Detailed reference viewed: 19 (2 ULg)
See detailSynthesis of hierarchical N-doped porous carbon structure/nanospheres Fe2O3 composites and its application in lithium-ion battery as lithium-ion anodes
Alkarmo, Walid ULg; Ouhib, Farid ULg; Aqil, Abdelhafid ULg et al

Poster (2017, May 04)

Nitrogen-doped porous carbons are of special interest, because their unique physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, and ... [more ▼]

Nitrogen-doped porous carbons are of special interest, because their unique physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, and are thus very important for applications in the fields of catalysis, environment techniques and energy generation and storage. Moreover, nitrogen-doping can be further amplified in a porous structure that bears a high surface area to increases their materials performance in electrochemical devices, such as double layer capacitors and lithium-ion batteries. In addition, nitrogen-doping can enhance the lithium insertion, between the nitrogen-doped carbon material and lithium. And it can create a large number of defects in the porous configuration and offer more active sites for lithium insertion. Toward this goal, a hierarchically structured macro- and mesoporous N-doped carbon with dispersed Fe2O3 nanoparticles (NDC@Fe2O3) is prepared by thermal treatment of a novel composite composed by PMMA particles decorated by graphene oxide (GO), PPy and iron salts. The NDC@Fe2O3 composite exhibited high surface area with a hierarchical pores structure. Integrated as a lithium ion battery anode, NDC@Fe2O3 exhibited high reversible capacity of 930 mA h/g over 200 cycles. The combination of Fe2O3 nanoparticles with nitrogen-doped porous carbons to form hybrid anode has been an efficient way to maintain the electronic integrity of the whole electrode since the carbon acts as a buffer layer to accommodate the volume variation and to provide multidimensional electron transport pathways during the charge/discharge process. [less ▲]

Detailed reference viewed: 61 (3 ULg)