25 research outputs found
SynthÚse et évaluation des propriétés antiparasitaires et antibactériennes de nouvelles fluoroquinolones
Le sujet de cette thĂšse concerne la synthĂšse de nouvelles fluoroquinolones et l Ă©valuation de leur potentiel en tant qu antiparasitaires (sur Toxoplasma gondii et Plasmodium spp) et antibactĂ©riens (sur Mycobacterium tuberculosis). Parmi une bibliothĂšque virtuelle de fluoroquinolones prĂ©dites comme trĂšs actives sur Toxoplasma gondii, quatre fluoroquinolones ont Ă©tĂ© choisies et synthĂ©tisĂ©es. Le potentien de ces fluoroquinolones a Ă©tĂ© Ă©valuĂ© in vitro sur des souches RH de T. gondii, sur des souches NF54-R de P. falciparum, sur des souches 265 BY de P. yoelli yoelli, sur des souches H37Rv de M. tuberculosis, ainsi que sur l ADN gyrase de M. tubeculosis. Parmi les quatre fluoroquinolones synthĂ©tisĂ©es et testĂ©es, une d entre elles se dĂ©tache clairement. Cette fluoroquinolone, en effet, est la seule Ă s ĂȘtre rĂ©vĂ©lĂ©e aussi active que prĂ©vu sur T. gondii, ce qui la place parmi les fluoroquinolones les plus actives sur ce parasite. De mĂȘme, elle est la seule Ă possĂ©der un effet schizonticide sur des hĂ©patocytes infectĂ©s par P. yoelii yoelii. Enfin, mĂȘme si sa concentration minimale inhibitrice sur M. tuberculosis est trĂšs Ă©levĂ©e, son inhibition de l activitĂ© de surenroulement de l ADN gyrase de M. tuberculosis est comparable aux fluoroquinolones les plus actives. Il serait intĂ©ressant d Ă©valuer les propriĂ©tĂ©s pharmacologiques de cette fluoroquinolone afin de voir si son usage comme antiparasitaire est envisageable.NICE-BU Sciences (060882101) / SudocSudocFranceF
Comparison of Electrochemical Immunosensors and Aptasensors for Detection of Small Organic Molecules in Environment, Food Safety, Clinical and Public Security
We review here the most frequently reported targets among the electrochemical immunosensors and aptasensors: antibiotics, bisphenol A, cocaine, ochratoxin A and estradiol. In each case, the immobilization procedures are described as well as the transduction schemes and the limits of detection. It is shown that limits of detections are generally two to three orders of magnitude lower for immunosensors than for aptasensors, due to the highest affinities of antibodies. No significant progresses have been made to improve these affinities, but transduction schemes were improved instead, which lead to a regular improvement of the limit of detections corresponding to ca. five orders of magnitude over these last 10 years. These progresses depend on the target, however
Quinone-Based Polymers for Label-Free and Reagentless Electrochemical Immunosensors: Application to Proteins, Antibodies and Pesticides Detection
Polyquinone derivatives are widely recognized in the literature for their remarkable properties, their biocompatibility, simple synthesis, and easy bio-functionalization. We have shown that polyquinones present very stable electroactivity in neutral aqueous medium within the cathodic potential domain avoiding side oxidation of interfering species. Besides, they can act as immobilized redox transducers for probing biomolecular interactions in sensors. Our group has been working on devices based on such modified electrodes with a view to applications for proteins, antibodies and organic pollutants using a reagentless label-free electrochemical immunosensor format. Herein, these developments are briefly reviewed and put into perspective
Projet PĂ©daGo! Transformons les pratiques entre pairs
International audienceRĂ©sumĂ©La pĂ©dagogie dans lâenseignement supĂ©rieur doit sâadapter Ă lâĂ©volution des formations, des pratiques dâenseignement, des modalitĂ©s dâĂ©valuation et des espaces dâapprentissage. Dans ce contexte de profonds changements se pose la question de lâaccompagnement des enseignants dans leur parcours de formation.Pour rĂ©pondre Ă ce besoin, au niveau local, cinq enseignants-chercheurs de diffĂ©rentes disciplines ont lancĂ© le projet PĂ©daGo! au sein de leur universitĂ©. Il vise Ă crĂ©er une communautĂ© de pratiques permettant le partage entre pairs et lâapprentissage collectif. Les actions menĂ©es dans le projet PĂ©daGo! sont de deux natures : dâune part, lâorganisation de dĂ©jeuners pĂ©dagogiques permet aux participants dâĂ©changer sur leurs pratiques, de partager leurs conceptions pĂ©dagogiques et de favoriser leur rĂ©flexivitĂ©. Un compte-rendu de chaque dĂ©jeuner et des ressources complĂ©mentaires sont proposĂ©s sur un espace documentaire partagĂ©. Dâautre part, la conception dâĂ©pisodes de podcast ont pour ambition de toucher un public plus large, de façon asynchrone. Les invitĂ©s du podcast, experts dans leur domaine, sont questionnĂ©s sur leurs expĂ©riences portant sur la mise en place dâune pratique pĂ©dagogique ou sur une thĂ©matique dâintĂ©rĂȘt pour les acteurs de lâenseignement.Un volet recherche est associĂ© au projet. MenĂ© par une chercheuse en Sciences de l'Ăducation, il sâinscrit dans le cadre dâune recherche-action et a pour problĂ©matique : comment promouvoir et encourager l'engagement actif des acteurs pĂ©dagogiques d'une institution, dans le cadre d'une communautĂ© de pratiques en favorisant une dynamique collective et collaborative ? Cette recherche prĂ©sente deux objectifs qui concernent chacun un niveaudistinct dâacteurs : les participants - bĂ©nĂ©ficiaires du projet - et les cinq membres concepteurs et animateurs du projet.Concernant les participants, la recherche vise Ă estimer leur engagement dans les actions proposĂ©es en lien avec leur intention de dĂ©part et leur Ă©valuation des actions. Des indicateurs spĂ©cifiques Ă chacune des actions ont Ă©tĂ© dĂ©finis (nombre de personnes inscrites au dĂ©jeuner, pratique actuelle en pĂ©dagogie, intention de changement, satisfaction, audience du podcastâŠ). Concernant les concepteurs, il sâagit dâestimer les effets de leur engagement et de leur implication dans le projet sur leur propre dĂ©veloppement professionnel, en termes de posture et de pratique. LâĂ©mergence de marqueurs de lâĂ©volution de leur posture est Ă©valuĂ©e en combinant deux mĂ©thodes de recherche qualitatives : des entretiens individuels et des focus groups en dĂ©but, milieu et fin du projet.Ce projet se dĂ©roule sur 2 ans. Lors du congrĂšs de lâAIPU, quatre dĂ©jeuners pĂ©dagogiques auront Ă©tĂ© organisĂ©s et quatre Ă©pisodes de podcasts diffusĂ©s. Les donnĂ©es associĂ©es Ă ces actions auront Ă©tĂ© recueillies. Lâanalyse des rĂ©sultats permettra dâillustrer lâĂ©volution des pratiques individuelles et la dynamique collective crĂ©Ă©e par cette nouvelle communautĂ©. La place de cette communautĂ© dans lâinstitution sera Ă©galement discutĂ©e.Une attention toute particuliĂšre sera portĂ©e Ă la transfĂ©rabilitĂ© du projet pour pĂ©renniser ou dupliquer cette initiative dans dâautres contextes pĂ©dagogiques
Laser Powder Bed Fusion thermal monitoring using optical fiber sensors: in situ measurements and modelling
International audienceWe performed temperature measurements in a part manufactured by Laser Powder Bed Fusion using optical fiber sensors. A simplified model of the process was developed, and the experimental measurements are compared to simulated temperature values
Fabrication and Use of Organic Electrochemical Transistors for Sensing of Metabolites in Aqueous Media
This review first recalls the basic functioning principles of organic electrochemical transistors (OECTs) then focuses on the transduction mechanisms applicable to OECTs. Materials constituting the active semiconducting part are reviewed, from the historical conducting polymers (polyaniline, polypyrrole) to the actual gold standard, poly-3,4-ethylenedioxythiophene: polystyrene sulfonic acid (PEDOT:PSS), as well as the methods used to fabricate these transistors. The review then focuses on applications of OECTs for the detection of small molecules and more particularly of metabolites, with a distinction between enzymatic and non-enzymatic transduction pathways. Finally, the few patents registered on the topic of OECT-based biosensors are reviewed, and new tracks of improvement are proposed
Surface heat flux estimation with embedded thermocouples and Fiber Bragg Grating sensor in ITER-like plasma facing components
International audienceThe main objective of WEST is to study the behavior of the ITER-like divertor monobloc components, test their resistance and ageing under ITER relevant heat loads.For the upcoming phase 2 of WEST, the lower divertor is now fully equipped with the ITER-like actively cooled bulk tungsten Plasma Facing Units (PFU), designed to withstand 10MW/m2 in steady state. This divertor is also equipped with an enlarged set of ThermoCouples (TCs x 16) and Fiber Bragg Gratings (FBGs) probes (x5) with 14 measurement spots each to evaluate the heat loading during the experiments. This paper presents the new TC and FBG diagnostics as well as the associated inverse method used to estimate the surface heat flux from the embedded temperature measurements in the divertor. The performance of each diagnostic will be evaluated with synthetic measurements generated with realistic heat flux intensity and distribution. The results of a parametrical analysis shows that each diagnostic is able to estimate the spatial distribution of the expected heat fluxes in WES
Lipophilic quinolone derivatives: Synthesis and in vitro antibacterial evaluation
International audienceThis paper reports on the design of a series of 10 novel lipophilic piperazinyl derivatives of the 1-cyclopropyl-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid, their synthesis, their characterisation by 1H, 13C and 19F NMR, IR spectroscopy and HRMS, as well as their biological activity against bacteria of medical interest. Among these derivatives, 2 were as potent as the parent quinolone against Neisseriagonorrhoeae whereas all the compounds displayed lower activity than the parent quinolone against other bacteria of medical interest. Our results showing that the increased lipophilicity was deleterious for antibacterial activity may help to design new quinolone derivatives in the future, especially lipophilic quinolones which have been poorly investigated previously