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Zwitterionic Polymers towards the Development of Orientation-Sensitive Bioprobes
No full textInternational audienceDynamics with an orientational degree of freedom are fundamental in biological events. Probes with polarized luminescence enable a determination of the orientation. Lanthanide-doped nanocrystals can provide more precise analysis than quantum dots due to the non-photoblinking/bleaching nature and the multiple line-shaped emission. However, the intrinsic polarization property of the original nanocrystals often deteriorates in complex physiological environments, because the colloidal stability easily breaks and the probes aggregate in the media with abundant salts and macromolecules. Engineering the surface chemistry of the probes is thus essential to be compatible with biosystems, which has remained a challenging task that should be exclusively addressed for each specific probe. Here, we demonstrate a facile and efficient surface functionalization of lanthanide-doped nanorods by zwitterionic block copolymers. Due to the steric interaction and the intrinsic zwitterionic nature of the polymers, high colloidal stability of the zwitterionic nanorod suspension is achieved over wide ranges of pH and concentration of salts, even giving rise to the lyotropic liquid crystalline behavior of the nanorods in physiological media. The shear-aligned ability is shown to be unaltered by the coated polymers and thus the strongly polarized emission of Eu 3+ is preserved. Besides, biological experiments reveal good biocompatibility of the zwitterionic nanorods with negligible non-specific binding. This study is a stepping stone for the use of the nanorods as orientation probes in biofluids and validates the strategy of coupling zwitterions to lanthanide-doped nanocrystals for various bio-applications
RNF213-associated urticarial lesions with hypercytokinemia
No full textInternational audienceBackground. Urticarial lesions are observed in both cutaneous and systemic disorders. Familial forms of urticarial syndromes are rare and can be encountered in systemic auto-inflammatory diseases.Objective. We investigated a large family with dominantly inherited chronic urticarial lesions associated with hypercytokinemia. Methods. We performed a genetic linkage analysis in 14 patients from a 5-generation family, as well as whole-exome sequencing, cytokine profiling and transcriptomic analyses on samples from two patients. The identified candidate protein was studied after in vitro expression of the corresponding normal and mutated recombinant proteins. An unsupervised proteomic approach was followed to unveil the associated protein network. Results. The disease phenotype of the most affected family members is characterized by chronic urticarial flares associated with extremely high plasma levels of pro- (IL-1B, IL-6, TNF-a) and anti-inflammatory (IL-10, IL1-RA) cytokines, with no secondary organ dysfunction, no susceptibility to infections, no fever and normal C-reactive protein levels. Monocyte transcriptomic analyses identified an immunotolerant profile in the most affected patient. Affected family members carried a loss-of-function mutation in RNF213 that encodes mysterin, a protein of poorly known physiological role. We identified the deubiquitinase CYLD, a major regulator of inflammation, as an RNF213 partner and showed that CYLD expression is inhibited by wild-type but not mutant RNF213.Conclusion. We identified a new entity characterized by chronic urticarial lesions associated with a clinically-blunted hypercytokinemia. This disease, due to a loss of function of RNF213, reveals mysterin’s key role in the complex molecular network of innate immunity
Volatile Organic Compounds Analysis as a Potential Novel Screening Tool for Breast Cancer: A Systematic Review
No full textInternational audienceIntroduction: An early diagnosis is crucial in reducing mortality among people who have breast cancer (BC). There is a shortfall of characteristic early clinical symptoms in BC patients, highlighting the importance of investigating new methods for its early detection. A promising novel approach is the analysis of volatile organic compounds (VOCs) produced and emitted through the metabolism of cancer cells.Methods: The purpose of this systematic review is to outline the published research regarding BC-associated VOCs. For this, headspace analysis of VOCs was explored in patient-derived body fluids, animal model-derived fluids, and BC cell lines to identify BC-specific VOCs. A systematic search in PubMed and Web of Science databases was conducted according to the PRISMA guidelines. ReSulTS: Thirty-two studies met the criteria for inclusion in this review.Results highlight that VOC analysis can be promising as a potential novel screening tool. However, results of in vivo, in vitro and case-control studies have delivered inconsistent results leading to a lack of intermatrix consensus between different VOC sampling methods. Discussion: Discrepant VOC results among BC studies have been obtained, highly due to methodological discrepancies. Therefore, methodological issues leading to disparities have been reviewed and recommendations have been made on the standardisation of VOC collection and analysis methods for BC screening, thereby improving future VOC clinical validation studies
Determination of the Effective Permeability of Doubly Porous Materials by a Two-Scale Homogenization Approach
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Optimisation de l’insertion d’implants orthopédiques non cimentés par une méthode acoustique basée sur l’analyse de la force d’impact
No full textSelon la Haute Autorité de Santé (HAS), environ 150 000 personnes subissent chaque année en France une pose de Prothèse Totale de Hanche (PTH). Malgré la fréquence de l’intervention, environ 5% à 10% d’échecs sont constatés dans les 10 ans suivant l’opération [1], ce qui pénalise les patients et engendre des coûts pour le système de santé. Dans le cas d’implants non-cimentés, la stabilité primaire de l’implant est en effet obtenue grâce aux contraintes qui s’exercent à l’interface avec l’os dues à un sous-dimensionnement de la cavité osseuse par rapport à la taille de l’implant. L’enjeu pour le chirurgien est donc d’insérer suffisamment l’implant afin d’éviter la création de micro- mouvements sans néanmoins provoquer de fracture péri-prothétique. Or, le chirurgien ne dispose d’aucun outil d’évaluation en temps-réel de l’état de stabilité de l’implant dans l’os et se base actuellement sur le son produit par le marteau lors de l’impact [2]. Dans cette étude qui porte sur la tige fémorale, nous nous intéresserons au signal de la force d’insertion, enregistrée grâce à un capteur de force présent sur la face d’impact du marteau orthopédique. Nous montrerons que la forme du signal évolue avec l’étape d’insertion de l’implant dans l’os et avec son enfoncement. En particulier, l’intérêt se portera sur l’étude des rebonds de la pièce impactée sur le marteau et un indicateur temporel, correspondant à la distance entre les deux premiers pics du signal, sera analysé au cours de l’insertion. Les résultats de deux études in silico et ex vivo seront également mis en perspective. Cette mesure dynamique des propriétés du système os-implant ouvre des perspectives quant au développement d’un outil d’aide à la décision pour les chirurgiens. [1] NJR. (2017) 14th Annual joint registry report [2] G. Whitwell et al., (2013) Proc Inst Mech Eng
Evolving genealogies for branching populations under selection and competition
No full textFor a continuous state branching process with two types of individuals which are subject to selection and density dependent competition, we characterize the joint evolution of population size, type configurations and genealogies as the unique strong solution of a system of SDE's. Our construction is achieved in the lookdown framework and provides a synthesis as well as a generalization of cases considered separately in two seminal papers by Donnelly and Kurtz (1999), namely fluctuating population sizes under neutrality, and selection with constant population size. As a conceptual core in our approach, we introduce the selective lookdown space which is obtained from its neutral counterpart through a state-dependent thinning of "potential" selection/competition events whose rates interact with the evolution of the type densities. The updates of the genealogical distance matrix at the "active" selection/competition events are obtained through an appropriate sampling from the selective lookdown space. The solution of the above mentioned system of SDE's is then mapped into the joint evolution of population size and symmetrized type configurations and genealogies, i.e. marked distance matrix distributions. By means of Kurtz's Markov mapping theorem, we characterize the latter process as the unique solution of a martingale problem. For the sake of transparency we restrict the main part of our presentation to a prototypical example with two types, which contains the essential features. In the final section we outline an extension to processes with multiple types including mutation
Reducing Choice-Blindness? An Experimental Study Comparing Experienced Meditators to Non-Meditators
No full textInternational audienceThe mindfulness trait is an intrinsic characteristic of one’s disposition that facilitates awareness of the present moment. Meditation has proven to enhance situational awareness. In this study, we compared the performance of participants that were split into two groups depending on their experience in mindfulness meditation (a control group naive to mindfulness meditation and a group of experienced mindfulness meditators). Choice-blindness happens when people fail to notice mismatches between their intentions and the consequences of decisions. Our task consisted of decisions where participants chose one preferred female facial image from a pair of images for a total of 15 decisions. By reversing the decisions, unbeknownst to the participants, three discrepancies were introduced in an online experimental design. Our results indicate that the likelihood of detecting one or more manipulations was higher in the mindful group compared to the control group. The higher FMI scores of the mindful group did not contribute to this observation; only the practice of mindfulness meditation itself did. Thus, this could be explained by better introspective access and control of reasoning processes acquired during practice and not by the latent characteristics that are attributed to the mindfulness trait
Pour une finance responsable et durable : entre promesses et défis
No full textInnovations - Le blog du Réseau de Recherche sur l’Innovatio
Direct-synthesis of AgxCu100-x bimetallic nanoparticles on p-Si supports for the photoelectrochemical reduction of CO2
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Invasion dans nos jardins : nouvelles révélations sur le ver plat mangeur de vers de terre
No full textInternational audienceA popular piece about the diet of the invasive land flatworm Obama nungara in gardens in France.Un article de vulgarisation sur le régime alimentaire du ver plat envahissant Obama nungara dans les jardins en France