Portail HAL UHA (Université de Haute-Alsace)
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L’Union européenne face aux menaces nucléaires et radiologiques. Etat des lieux des instruments juridiques de prévention et de réponse
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Approaches for positioning the active medium in hybrid nanoplasmonics. Focus on plasmon-assisted photopolymerization
No full textInternational audienceOver the past 20 years, hybrid plasmonics for nanoemitters of light or for nanoabsorbers, based on weak or strong coupling between metallic nanocavities and active media (emissive or absorbing entities), have given rise to important research efforts. One of the main current challenges is the control +of the nanoscale spatial distribution and associated symmetry of the active medium in the vicinity of the metallic nanoparticles. In this review, we first recall the main principles of weak and strong coupling by stressing the importance of controlling the spatial distribution of the active medium and present the main approaches developed for achieving this control. Nine different approaches are identified. We then focus our attention on one of them based on plasmonic photopolymerization and discuss the flexibility of this approach in terms of control of the spatial symmetry of the hybrid nanosystem metal−polymer nanoemitters and the resulting polarization dependence of the light emission. The different approaches are analyzed and compared with each other, and some future perspectives and challenges are finally discussed
Therapeutic Contribution of Tau-Binding Thiazoloflavonoid Hybrid Derivatives Against Glioblastoma Using Pharmacological Approach in 3D Spheroids
No full textInternational audienceGrowing evidence has unveiled the pathological significance of Tau in many cancers, including the most aggressive and lethal brain tumor glioblastoma multiform (GBM). In this regard, we have recently examined the structure–activity relationship of a new series of seventeen 2-aminothiazole-fused to flavonoid hybrid compounds (TZF) on Tau-overexpressing GBM cells. Here, we evaluated the anticancer activities of the two lead compounds 2 and 9 using multi-cellular spheroids (MCSs) which represent an easy 3D human cell model to mimic GBM organization, physical constraints and drug penetration. The two compounds reduced cell evasion from spheroids up to three times, especially for Tau-expressing cells. As a first step towards a therapeutic approach, we quantified the effects of these compounds on MCS growth using two complementary protocols: single and repeated treatments. A single injection with compound 9 slowed down the growth of MCSs formed with U87 shCTRL cells by 40% at 10 µM. More interestingly, multiple treatment with compound 9 slowed the growth of U87 shCTRL spheroids by 40% at a concentration of 5 µM, supporting the increased bioavailability of compound 9 within MCSs. In conclusion, compound 9 deserves particular attention as promising candidate for specifically targeting Tau-expressing cancers such as GBM
Enhancing Wastewater Depollution: Sustainable Biosorption Using Chemically Modified Chitosan Derivatives for Efficient Removal of Heavy Metals and Dyes
No full textInternational audienceDriven by concerns over polluted industrial wastewater, particularly heavy metals and dyes, this study explores biosorption using chemically cross-link chitosan derivatives as a sustainable and cost-effective depollution method. Chitosan cross-linking employs either water-soluble polymers and agents like glutaraldehyde or copolymerization of hydrophilic monomers with a cross-linker. Chemical cross-linking of polymers has emerged as a promising approach to enhance the wet-strength properties of materials. The chitosan thus extracted, as powder or gel, was used to adsorb heavy metals (lead (Pb2+) and copper (Cu2+)) and dyes (methylene blue (MB) and crystal violet (CV)). Extensive analysis of the physicochemical properties of both the powder and hydrogel adsorbents was conducted using a range of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM), as well as 1H and 13C nuclear magnetic resonance (NMR). To gain a comprehensive understanding of the sorption process, the effect of contact time, pH, concentration, and temperature was investigated. The adsorption capacity of chitosan powder for Cu(II), Pb(II), methylene blue (MB), and crystal violet (CV) was subsequently determined as follows: 99, 75, 98, and 80%, respectively. In addition, the adsorption capacity of chitosan hydrogel for Cu(II), Pb(II), MB, and CV was as follows: 85, 95, 85, and 98%, respectively. The experimental data obtained were analyzed using the Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models. The isotherm study revealed that the adsorption equilibrium is well fitted to the Freundlich isotherm (R2 = 0.998), and the sorption capacity of both chitosan powder and hydrogel was found to be exceptionally high (approximately 98%) with the adsorbent favoring multilayer adsorption. Besides, Dubinin has given an indication that the sorption process was dominated by Van der Waals physical forces at all studied temperatures
Multi-scale thermal degradation of wood pellets under low heating rates: Experiments and modeling
No full textInternational audiencePyrolysis and combustion experiments were carried out on a single wood pellet in a drop tube furnace, under a heating rate of 5 °C/min. Kinetic modeling was done using the Extended Independent Parallel Reaction model. Three reactions were considered in the pyrolysis case and only one in the combustion case. In the pyrolysis case, a thermal model was proposed which is coupled with the kinetic model to correct the temperature inside the pellet. In the combustion case, the mass rate curve was compared to that of the main gaseous emissions. The mass and mass rate curves between the combustions of a pellet in the drop tube furnace and of pellet sawdust in a thermobalance under the same heating rate were compared
Proust et Einstein
No full textInternational audienceProust followed the development of Einstein's theory of relativity, first special and then general, as his work grew. Towards the end of his career, he was interested to see the two conceptions of time compared, although he suffered from not being able to understand the physicist's mathematical demonstrations. This article attempts to identify what, in the novelist's conception of spacetime, explains this analogy, which was noticed by contemporaries, and to illustrate that, through the construction and development of the characters, the comparison leads deeper into the structures of the novel cycle.Proust suit le développement de la théorie de la relativité, restreinte puis générale, d’Einstein en même temps que s’accroît son œuvre. Vers la fin de sa création, il est intéressé de voir comparer les deux conceptions du temps, quoique souffrant de ne pouvoir comprendre les démonstrations mathématiques du physicien. L’article tente de cerner ce qui, dans la conception de l’espace-temps chez le romancier, explique cette analogie remarquée par les contemporains pour illustrer qu’à travers la construction et l’évolution des personnages, le rapprochement mène plus profondément dans les structures du cycle romanesque
graft4dendrogram
No full textThis R code offers a function to add a new leaf to a dendrogram.The proposed algorithm find the best point to graft the new leaf and perform the graft.A demo and an evaluation test codes are provided
« André Gide la question religieuse. Un sujet critique »
No full textInternational audienceAu cours de sa vie, Gide développe avec le christianisme un rapport controversé. La question occupe l’ensemble de son œuvre, du Journal aux fictions, mais aussi son Christianisme contre le Christ, livre jamais publié. Sa pensée religieuse a fait l’objet de maintes études déjà à partir des années 50. Dans le but d’interroger les diverses facettes « critiques » de ce sujet délicat, cette contribution se propose d’abord de rappeler les éléments fondamentaux de sa critique du christianisme et ensuite d’examiner comment la question religieuse est traitée dans les ouvrages critiques des années 50 et 60 qui se sont penchées sur ce sujet délicat et notamment celles de Charles Moeller, Henri Planche, Laurent Gagnebin, Elsie Pell, pour finir avec celle de Catharine H. Savage, qui reste encore aujourd’hui une référence importante dans le domaine
Éditer les Diverses leçons d’Antoine du Verdier : montage, démontage et intertextualité
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Effect of arbuscular mycorrhizal symbiosis on grapevine response to Neofusicoccum parvum, a major trunk disease fungus
No full textInternational audienceGrapevine is an economically-important culture worldwide but is currently the target of decline, especially caused by grapevine trunk diseases (GTD). One of the major grapevine trunk disease is Botryosphaeria dieback, which is associated with Botryosphaeriaceae fungi. Among the different methods that could contribute to increase grapevine fitness under stresses, viticulture could take advantage of symbiosis with arbuscular mycorrhizal fungi. Within this context, we investigated the effect of V. vinifera cv. Gewurztraminer colonization with the arbuscular mycorrhizal fungus Rhizophagus irregularis on plant tolerance to wood inoculation with Neofusicoccum parvum Bt67, one of the most aggressive fungus associated with Botryosphaeria dieback. We showed that grapevine mycorrhization resulted in a small but significant reduction of wood necrosis size and less intense necrosis symptoms on the leaves. We further characterized the response of grapevine leaves and roots to both arbuscular mycorrhizal fungus (AMF) symbiosis and GTD fungus inoculation, especially the interaction between these two conditions, with a non-targeted metabolomic approach. In the roots, both mycorrhization and N. parvum infection triggered metabolite reprogramming, especially sugars and stilbenes, which were downregulated by both AMF symbiosis and pathogen infection. Furthermore, N. parvum infection triggered a significant decrease in fatty acids and oxylipins in leaves of non-mycorrhized plants, whereas contents were maintained or increased in Rhizophagus irregularis-colonized plants. In conclusion, AMF symbiosis may be an interesting tool to improve health of young grapevines and help sustaining infection by trunk disease fungi, by harnessing lipid metabolism