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Aerobic Mukaiyama-type oxidation of essential oil of ortanic tangor from Reunion Island: an applied example of valorization on terpenes using salophen complexes
No full textInternational audienceThe work described in this comprehensive study is based on valorising essential oils from citrus originated from Réunion Island, ortanic tangor, using Mukaiyama-type aerobic oxidation of terpenes, in particular limonene. This innovative work combines extraction, fractionation and catalytic oxidation to transform an agricultural residue into valuable compounds, while respecting the principles of green chemistry. The research highlights the use of metal salophen complexes based on cheap and abundant transition metals to achieve mild epoxidation at room temperature. In addition, a theoretical study using DFT provided a better understanding of the mechanism of this reaction for the best catalyst (molybdenum containing), suggesting that the activator could be a molybdenum oxo-cis-{MoVIO2} species resulting from the evolution of the initial catalyst
Structural, optical, and electronic properties of europium orthophosphate: a combination of experimental and theoretical studies
No full textInternational audienceWe investigated three transition types, combining DFT and UV-Vis. Eu 3+ triggers 4f–4f and 4f–5d. PO 3 units causes the last one
Red Blood Cell Glycation Triggers In Vivo Cerebral Erythrophagocytosis in Adult Zebrafish in a Model Mimicking Hemorrhagic Stroke
No full textInternational audienceHemorrhagic stroke, particularly intracerebral hemorrhage (ICH), is a highly lethal subtype of stroke, responsible for a poor prognosis and a high rate of disability. ICH is characterized by the extravasation of red blood cells (RBCs) into the central nervous system. Efficient clearance of RBC lysis products is critical. Erythrophagocytosis may serve as a key protective mechanism in mitigating secondary damage of ICH. Interestingly, diabetes is known to promote RBC glycation and to exacerbate the consequences of ICH. However, the link between glycation, RBC clearance and neurological outcomes after ICH is not clear. In this study, we aimed to decipher the role of glycated RBCs in ICH. For this, we used human RBCs glycated by methylglyoxal (MGO), an intermediate product of glycolysis recognized as one of the most potent glycating agents in humans. These glycated RBCs displayed altered morphology, reduced deformability capacity and increased eryptosis. We then proceeded to RBC microinjection into the brain parenchyma of Tg(mpeg1.1:mCherry) zebrafish allowing the visualization of both microglia and macrophages. Although the presence of RBCs in the parenchyma did not affect the increased recruitment of mpeg1.1-positive cells to the injection site compared to vehicle injection, RBC glycation significantly enhanced erythrophagocytosis. In conclusion, we established an innovative model of ICH, and we demonstrated enhanced RBC phagocytosis in the brain under glycated conditions. Further research is needed to understand the consequence of such process in ICH damage. Finally, our model may contribute to the identification of specific neurorestorative therapeutics aimed at improving brain plasticity after stroke in diabetic context
Bases génétiques et moléculaires de la résistance à la fusariose chez le vanillier. Approches RNA-Seq et QTL chez Vanilla planifolia
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/616349/)International audienc
Sweet taste induced by miraculin from Sisrè pulp (Synsepalum dulcificum Schumach. & Thonn.) from Benin as affected by heat treatment
No full textInternational audienceThis work focused on the effect of heating treatments on the sweetening property of miraculin contained in Sisrè, the fruit of Synsepalum dulcificum, from Benin. The aim was to define suitable conditions for stabilizing the fruit pulp, at a lower cost while preserving its functional properties. The fruits, collected in the locality of Sèhouè in the Republic of Benin, were frozen whole, pulped and then stored at -20 • C before processing and analyzing. Heat treatments ranging from 40 to 70 • C were applied to the fresh pulp for 5 min. Sensory tests were performed on the heated pulp samples to test the functionality of miraculin and determine the remanence time of the induced sweet taste after treatment at different temperatures. Reverse-phase and steric-exclusion chromatography, in association with electrophoresis were performed to analyze the miraculin content of the pulps, and the generated data were compared with the sensory results. Sensory analysis showed that the sweetening effect of the native pulp before heat treatment lasted at least >1 h 30 min. A significant loss of functionality after exposure of the pulp to temperature values above 50 • C was observed. The results of analyses also showed that from 50 • C, the miraculin concentration decreased significantly. At temperature values above 50 • C, miraculin completely lost its functionality even if the pulp still contained miraculin, probably in its monomeric form that are not active. The intensity and remanence of the sweetening effect of miraculin depended on its concentration. These results demonstrated that the pulp of Sisrè cannot be stabilized by thermal pasteurization and that drying at low temperatures between 40 and 50 • C could be a good technological option for preserving its functionality
Francophonie, plurilinguisme et identité narrative : stylistique du métissage linguistique dans Les cigognes sont immortelles d’Alain Mabanckou
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Earliest evidence of elephant butchery at Olduvai Gorge (Tanzania) reveals the evolutionary impact of early human megafaunal exploitation
No full textInternational audienceIn this valuable study, the authors present traces of bone modification on ~1.8 million-year-old proboscidean remains from Tanzania, which they infer to be the earliest evidence for stone-toolassisted megafaunal consumption by hominins. Challenging published claims, the authors argue that persistent megafaunal exploitation roughly coincided with the earliest Acheulean tools. Notwithstanding the rich descriptive and spatial data, the behavioral inferences about hominin agency rely on traces (such as bone fracture patterns and spatial overlap) that are not unequivocal; the evidence presented to support the inferences thus remains incomplete. Given the implications of the timing and extent of hominin consumption of nutritious and energy-dense food resources, as well as of bone toolmaking, the findings of this study will be of interest to paleoanthropologists and other evolutionary biologists