Electroactive 1,5-benzodiazepines bearing either a tetrathiafulvalene or a ferrocene moiety

International audienceThe synthesis of a series of electroactive 1,5-benzodiazepines bearing either a ferrocene or tetrathiafulvalene core, acting as the electroactive moiety, is reported. The electron donating ability of these redox active 1,5-benzodiazepines is described together with their molecular structures, investigated by X-ray diffraction studies

Amélioration du processus de vérification des architectures générées à l'aide d'outils de synthèse de haut-niveau

L'augmentation de la capacité d'intégration des circuits a permis le développement des systèmes de plus en plus complexes. De cette complexité sont nés des besoins conséquents quant aux méthodes de conception et de vérification. Les outils de synthèse de haut-niveau (HLS) sont une des réponses à ces besoins. Les travaux présentés dans cette thèse ont pour cadre l'amélioration du processus de vérification des architectures matérielles synthétisées par HLS. En particulier, ils proposent une méthode pour la transformation des assertions booléennes spécifiées dans la description algorithmique d'une application en moniteurs matériels pour la simulation. Une deuxième méthode est proposée. Elle cible la synthèse automatique d'un gestionnaire d'erreurs matériel dont le rôle est d'archiver les erreurs survenant dans un circuit en fonctionnement réel, ainsi que leurs contextes d'exécution.The fast growing complexity of hardware circuits, during the last three decades, has change devery step of their development cycle. Design methods evolved a lot, and this evolutionwas necessary to cope with an always shorter time-to-market, mainly driven by the internationalcompetition.An increased complexity also means more errors, harder to find corner-cases, and morelong and expensive simulations. The verification of hardware systems requires more andmore resources, and is the main cost factor of the whole development of a circuit. Since thecomplexity of any system increases, the cost of an error undetected until the foundry stepbecame prohibitive. Therefore, the verification process is divided between multiple stepsinvolved at every moment of the design process : comparison of models behavior, simulationof RTL descriptions, formal analysis of algorithms, assertions usage, etc. The verificationmethodologies evolved a lot, in order to follow the progress of design methods. Somemethods like the Assertion-Based Verification became so important that they are nowwidely adopted among the developers community, providing near-source error detection.Thus, the work described here aims at improving the assertion-based verification process,in order to offer a consequent timing improvment to designers. Two contributions aredetailed. The first one deals with the transformation of Boolean assertions found in algorithmicdescriptions into equivalent temporal assertions in the RTL description generatedby high-level synthesis (HLS) methodologies. Therefore, the assertions are usable duringthe simulation process of the generated architectures. The second contribution targets theverification of hardware systems in real-time. It details the synthesis process of a hardwareerror manager, which has to save and serialize the execution context when an error isdetected. Thus, it is easier to understand the cause of an error and to find its source. Theerrors and their contexts are serialized as reports in a memory readable by the system ordirectly by the designer. The behavior of a circuit can be analyzed without requiring anyprobe or integrated logic analyzer.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Chiral electron-rich bis(cyclopentadienyl) dithiolene molybdenum complexes

International audienceEnantiomerically pure electron rich Cp2Mo(dithiolene) complexes have been synthesized from the enantiopure dithiolene ligands, namely the (R)- and the (S)-3(1-phenylethyl)-1,3-thiazoline-2-thione-4,5-dithiolate ligands. These heteroleptic molybdenum complexes act as very good electron donors, as demonstrated through electrochemical investigations. Both isomers form charge transfer salts with TCNQ with a 1:1 stoechiometry which have been characterized by single crystal X-ray diffraction, EPR and UV–vis spectroscopic investigations. Circular dichroism (CD) experiments were also carried out on the neutral (R) and (S) enantiomers as well as on the mono oxidized species of these Cp2Mo dithiolene complexes

Formol et fixation : nouvelle donne, nouvelles approches…

Mise au point par les chercheurs du Muséum national d’Histoire naturelle à la station de Biologie marine de Concarneau, la technique décrite ici consiste à fixer des poissons au formaldéhyde sous hyperbarie. Élaboré avec pour souci principal une exposition la plus réduite possible du manipulateur aux vapeurs de formol, le champ d’application de ce nouveau procédé s’étend notamment à la sauvegarde, au conditionnement et au transport de certains spécimens des collections des muséums

Mixed-valence gold bis (diselenolene) complex turning metallic under pressure.

While oxidation of d8 anionic gold bis(dithiolene) complexes most often affords the corresponding neutral radical single-component conductor, an original gold bis(diselenolene) complex isolated as a Ph4P+ salt affords upon electrocrystallization a mixed-valence 1 : 2 salt, [Ph4P][Au(Me-thiazds)2]2 (Me-thiazds: 2-methyl-1,3-thiazoline-2-thione-4,5-diselenolate). This salt exhibits a rare charge alternation associated with the simultaneous presence of both cis and trans isomers of the gold complex in the conducting layers. The salt is semiconducting (σRT = 3 × 10−2 S cm−1, Eact = 0.137 eV) but, in contrast with other 1 : 2 gold bis(dithiolene) salts, turns metallic under pressure (>10 GPa). [Ph4P][Au(Me-thiazds)2]2 is thus the first metallic, fully characterized, 1 : 2 mixed-valence gold complex, opening the door for the preparation of highly conducting solids of this type

Rapid Enzyme-linked Immunosorbent Assay for Detection of the Algal Toxin Domoic Acid

Domoic acid (DA) is a potent toxin produced by bloom-forming phytoplankton in the genus Pseudo-nitzschia, which is responsible for causing amnesic shellfish poisoning (ASP) in humans. ASP symptoms include vomiting, diarrhea, and in more severe cases confusion, loss of memory, disorientation, and even coma or death. This paper describes the development and validation of a rapid, sensitive, enzyme linked immunosorbent assay test kit for detecting DA using a monoclonal antibody. The assay gives equivalent results to those obtained using standard high performance liquid chromatography, fluorenylmethoxycarbonyl high performance liquid chromatography, or liquid chromatography—mass spectrometry methods. It has a linear range from 0.1–3 ppb and was used successfully to measure DA in razor clams, mussels, scallops, and phytoplankton. The assay requires approximately 1.5 h to complete and has a standard 96-well format where each strip of eight wells is removable and can be stored at 4°C until needed. The first two wells of each strip serve as an internal control eliminating the need to run a standard curve. This allows as few as 3 or as many as 36 duplicate samples to be run at a time enabling real-time sample processing and limiting degradation of DA, which can occur during storage. There was minimal cross-reactivity in this assay with glutamine, glutamic acid, kainic acid, epi- or iso-DA. This accurate, rapid, cost-effective, assay offers environmental managers and public health officials an effective tool for monitoring DA concentrations in environment samples

The Spatial Architecture of Bacillus subtilis Biofilms Deciphered Using a Surface-Associated Model and In Situ Imaging

The formation of multicellular communities known as biofilms is the part of bacterial life cycle in which bacteria display cooperative behaviour and differentiated phenotypes leading to specific functions. Bacillus subtilis is a Gram-positive bacterium that has served for a decade as a model to study the molecular pathways that control biofilm formation. Most of the data on B. subtilis biofilms have come from studies on the formation of pellicles at the air-liquid interface, or on the complex macrocolonies that develop on semi-solid nutritive agar. Here, using confocal laser scanning microcopy, we show that B. subtilis strains of different origins are capable of forming biofilms on immersed surfaces with dramatically protruding “beanstalk-like” structures with certain strains. Indeed, these structures can reach a height of more than 300 µm with one undomesticated strain from a medical environment. Using 14 GFP-labeled mutants previously described as affecting pellicle or complex colony formation, we have identified four genes whose inactivation significantly impeded immersed biofilm development, and one mutation triggering hyperbiofilm formation. We also identified mutations causing the three-dimensional architecture of the biofilm to be altered. Taken together, our results reveal that B. subtilis is able to form specific biofilm features on immersed surfaces, and that the development of these multicellular surface-associated communities involves regulation pathways that are common to those governing the formation of pellicle and/or complex colonies, and also some specific mechanisms. Finally, we propose the submerged surface-associated biofilm as another relevant model for the study of B. subtilis multicellular communities

Pharmacokinetic aspects of retinal drug delivery

Drug delivery to the posterior eye segment is an important challenge in ophthalmology, because many diseases affect the retina and choroid leading to impaired vision or blindness. Currently, intravitreal injections are the method of choice to administer drugs to the retina, but this approach is applicable only in selected cases (e.g. anti-VEGF antibodies and soluble receptors). There are two basic approaches that can be adopted to improve retinal drug delivery: prolonged and/or retina targeted delivery of intravitreal drugs and use of other routes of drug administration, such as periocular, suprachoroidal, sub-retinal, systemic, or topical. Properties of the administration route, drug and delivery system determine the efficacy and safety of these approaches. Pharmacokinetic and pharmacodynamic factors determine the required dosing rates and doses that are needed for drug action. In addition, tolerability factors limit the use of many materials in ocular drug delivery. This review article provides a critical discussion of retinal drug delivery, particularly from the pharmacokinetic point of view. This article does not include an extensive review of drug delivery technologies, because they have already been reviewed several times recently. Instead, we aim to provide a systematic and quantitative view on the pharmacokinetic factors in drug delivery to the posterior eye segment. This review is based on the literature and unpublished data from the authors' laboratory.Peer reviewe

Innovation et développement dans les systèmes agricoles et alimentaires

L’innovation est souvent présentée comme l’un des principaux leviers pour promouvoir un développement plus durable et plus inclusif. Dans les domaines de l’agriculture et de l’alimentation, l’innovation est marquée par des spécificités liées à sa relation à la nature, mais aussi à la grande diversité d’acteurs concernés, depuis les agriculteurs jusqu’aux consommateurs, en passant par les services de recherche et de développement. L’innovation émerge des interactions entre ces acteurs, qui mobilisent des ressources et produisent des connaissances dans des dispositifs collaboratifs, afin de générer des changements. Elle recouvre des domaines aussi variés que les pratiques de production, l’organisation des marchés, ou les pratiques alimentaires. L’innovation est reliée aux grands enjeux de développement : innovation agro-écologique, innovation sociale, innovation territoriale, etc. Cet ouvrage porte un regard sur l’innovation dans les systèmes agricoles et alimentaires. Il met un accent particulier sur l’accompagnement de l’innovation, en interrogeant les méthodes et les organisations, et sur l’évaluation de l’innovation au regard de différents critères. Il s’appuie sur des réflexions portées par différentes disciplines scientifiques, sur des travaux de terrain conduits tant en France que dans de nombreux pays du Sud, et enfin sur les expériences acquises en accompagnant des acteurs qui innovent. Il combine des synthèses sur l’innovation et des études de cas emblématiques pour illustrer les propos. L’ouvrage est destiné aux enseignants, professionnels, étudiants et chercheurs