New insulation fiberboards from sunflower cake with improved thermal and mechanical properties

New insulation fiberboards from sunflower cake with improved thermal and mechanical properties were produced by pressing at ambient temperature. Best compromise between mechanical and heat insulation properties (λ = 77.6 mW/m K at 25°C) was a starch-based board with 20% binder content. Because of its promising heat insulation properties, this new fiberboard could be positioned on walls and ceilings for thermal insulation of buildings. The bulk cake was an even better insulation material (only 62.0 mW/m K for thermal conductivity at 25°C): usable as loose fill in the attics of houses

Development and application of methodologies using continuous flow for the synthesis of API and diazo compounds

La chimie en flux continu a eu un impact significatif sur la chimie organique, offrant aux chimistes un ensemble d'outils pour la production efficace d'ingrédients pharmaceutiques actifs (IPAs) ainsi que pour la synthèse plus sécurisée de composés dangereux tels que les composés diazoïques. Cette thèse présente de nouvelles méthodologies développées en utilisant la chimie en flux continu pour la synthèse d'APIs et de composés diazoïque. Le chapitre 1 propose un aperçu de la chimie en flux continu, en exposant ses avantages et ses défis afin d’établir une base solide pour le travail présenté dans les chapitres suivants. Le chapitre 2 décrit le développement d'un processus en deux étapes en flux continu pour la synthèse du propofol. Le processus commence par une réaction de Friedel-Crafts en conditions acides, suivie d'une extraction liquide-liquide et d'une étape de décarboxylation en conditions basiques à des températures élevées. Cette méthode a été réalisée sur une échelle de 60 grammes du produit de départ 4-hydroxybenzoate de méthyle, produisant du propofol avec une très bonne pureté à la suite de la distillation. Il est à noter que la chimie en flux continu a réduit le temps de réaction de 12 heures (en traitement par lots) à seulement 40 minutes, tout en permettant de maintenir des rendements comparables. Les chapitres 3, 4 et 5 se concentrent sur de nouvelles stratégies pour la préparation et l'application des composés diazoïques en flux continu. Le chapitre 3 introduit brièvement les composés diazoïques avec une emphase sur les méthodologies pour leurs préparations en flux continu, tandis que le chapitre 4 présente le développement d'une réaction de transfert de composé diazoïque utilisant une base supportée sur du polystyrène et l’azoture de nonafyle (NfN3) comme agent de transfert de diazo. Cette méthode a permis la synthèse de composés α-diazocarbonyle, incluant le méthyle 2-diazo-2-nitroacétate qui a été utilisé dans des réactions de cyclopropanation catalysées par un complexe de rhodium (II) avec divers alcènes et styrènes pour démontrer l’utilité de l'approche. Le chapitre 5 présente une autre méthodologie pour préparer les composés diazoïques, mais impliquant l'oxydation d'hydrazones utilisant un iode polyvalent. Des efforts ont été réalisés pour transférer cette méthodologie de chimie à réacteur fermé vers la chimie en flux continu. Tout d'abord, des composés diazoïques semi-stabilisés ont été préparés avec un temps de résidence court (1.5 minutes) et qui ont été quantifier dans la réaction suivante avec des acides carboxyliques ou des phénols. Une mise à l'échelle du gramme a été réalisée, et une deuxième approche a permis la préparation de composés diazoïques non stabilisés. Ceux-ci ont été utilisés in situ avec l’acide benzoïque pour obtenir des esters dans de bons rendements. Le chapitre 6 démontre des cycloadditions de composés diazoïques non stabilisés avec des alcynes-SF5 utilisés pour former des nouveaux composés SF5-3H-pyrazoles. Les pyrazoles peuvent être chauffés et peuvent subir une transposition sigmatropique [1,5] (réarrangement de van Alphen-Huttel). Ces réarrangements ainsi que les sélectivités obtenues avec les cycloadditions ont été étudiées par DFT.The advent of continuous flow chemistry has revolutionized the field of organic synthesis, offering chemists a versatile and powerful toolset for the efficient, on-demand production of active pharmaceutical ingredients (APIs) and the safe synthesis of hazardous compounds, such as diazo intermediates. The thesis introduces new methodologies developed using continuous flow for the synthesis of APIs and diazo compounds. Chapter 1 provides an overview of continuous flow chemistry, outlining its advantages and challenges to establish a solid foundation for the work presented in subsequent chapters. Chapter 2 details the development of a two-step continuous flow process for synthesizing propofol. The process begins with a Friedel-Crafts reaction under acidic conditions, followed by a liquid-liquid phase separation and a decarboxylation step under basic conditions at elevated temperatures. The method was successfully scaled up to 60 grams of the starting material methyl 4-hydroxybenzoate, yielding high purity propofol after distillation. Notably, continuous flow chemistry reduced the reaction time from 12 hours (in batch processing) to just 40 minutes while maintaining comparable yields. Chapters 3, 4, and 5 focus on strategies for the preparation and application of diazo compounds using continuous flow techniques. Chapter 3 introduces a brief overview of diazo compounds with an emphasis on continuous flow methodologies for their preparation, while Chapter 4 presents the development of a diazo transfer reaction using a polystyrene-supported base and nonaflyl azide (NfN3) as the diazo transfer agent. The method enabled the synthesis of α-diazocarbonyl compounds, including methyl 2-diazo-2-nitroacetate which was subsequently utilized in rhodium(II) catalyzed cyclopropanation reactions with various alkenes and styrenes to demonstrate the approach's utility. In Chapter 5, the use of iodosylbenzene as an oxidant in continuous flow chemistry is explored for synthesizing semi- and non-stabilized diazo compounds. The transition from batch to continuous flow enabled the efficient synthesis of semi-stabilized diazo compounds with short residence times (1.5 minutes), allowing for subsequent reactions with carboxylic acids or phenols. The methodology was also successfully scaled to gram quantities, and a second approach allowed for the synthesis of non-stabilized diazo compounds which were reacted in situ with benzoic acid. Finally, Chapter 6 describes the cycloadditions of non-stabilized diazo compounds with SF₅-alkynes to generate novel SF5-3H-pyrazoles. These pyrazoles could also undergo a [1,5]-sigmatropic shift (van Alphen-Hüttel rearrangement) upon heating. The mechanism of the rearrangement and the selectivities obtained with the cycloadditions were further investigated using DFT studies

Granzyme B enters the mitochondria in a Sam50-, Tim22- and mtHsp70-dependent manner to induce apoptosis

We have found that granzyme B (GB)-induced apoptosis also requires reactive oxygen species resulting from the alteration of mitochondrial complex I. How GB, which does not possess a mitochondrial targeting sequence, enter this organelle is unknown. We show that GB enters the mitochondria independently of the translocase of the outer mitochondrial membrane complex, but requires instead Sam50, the central subunit of the sorting and assembly machinery that integrates outer membrane β- barrel proteins. Moreover, GB breaches the inner membrane through Tim22, the metabolite carrier translocase pore, in a mitochondrial heat-shock protein 70 (mtHsp70)-dependent manner. Granzyme A (GA) and caspase-3 use a similar route to the mitochondria. Finally, preventing GB from entering the mitochondria either by mutating lysine 243 and arginine 244 or depleting Sam50 renders cells more resistant to GB-mediated reactive oxygen species and cell death. Similarly, Sam50 depletion protects cells from GA-, GM- and caspase-3-mediated cell death. Therefore, cytotoxic molecules enter the mitochondria to induce efficiently cell death through a noncanonical Sam50-, Tim22- and mtHsp70-dependent import pathway

Cardiomyocyte overexpression of neuronal nitric oxide synthase delays transition toward heart failure in response to pressure overload by preserving calcium cycling.

International audienceBACKGROUND: Defects in cardiomyocyte Ca(2+) cycling are a signature feature of heart failure (HF) that occurs in response to sustained hemodynamic overload, and they largely account for contractile dysfunction. Neuronal nitric oxide synthase (NOS1) influences myocyte excitation-contraction coupling through modulation of Ca(2+) cycling, but the potential relevance of this in HF is unknown. METHODS AND RESULTS: We generated a transgenic mouse with conditional, cardiomyocyte-specific NOS1 overexpression (double-transgenic [DT]) and studied cardiac remodeling, myocardial Ca(2+) handling, and contractility in DT and control mice subjected to transverse aortic constriction (TAC). After TAC, control mice developed eccentric hypertrophy with evolution toward HF as revealed by a significantly reduced fractional shortening. In contrast, DT mice developed a greater increase in wall thickness (P<0.0001 versus control+TAC) and less left ventricular dilatation than control+TAC mice (P<0.0001 for both end-systolic and end-diastolic dimensions). Thus, DT mice displayed concentric hypertrophy with fully preserved fractional shortening (43.7+/-0.6% versus 30.3+/-2.6% in control+TAC mice, P<0.05). Isolated cardiomyocytes from DT+TAC mice had greater shortening, intracellular Ca(2+) transients, and sarcoplasmic reticulum Ca(2+) load (P<0.05 versus control+TAC for all parameters). These effects could be explained, at least in part, through modulation of phospholamban phosphorylation status. CONCLUSIONS: Cardiomyocyte NOS1 may be a useful target against cardiac deterioration during chronic pressure-overload-induced HF through modulation of calcium cycling

An autonomous method of optimization targeting for an object detection system based on responsability analysis

Object extraction systems performances are not homogeneous over different corpora because objects can take many different aspects within such sets. An adaptation of these systems is thus required in order to maintain equal performances over every kind of object the system may be applied on. Focusing on the issue of parameters optimization, a method has been developed to restrict optimization to parameters of operators which compose the system, responsible for the different categories of errors produced by the system. Two stages are involved in our method. The first one is dedicated to the analysis of the system performances and leads to the extraction of the different error categories already mentionned. The second one relates to the analysis of the behavior of the different operators, leading to extract a single operator responsible for each error category. Experiments have been carried out over a video text detection system.Les systèmes d'extraction d'objets sont mis à mal par la diversité de ces derniers. Leur adaptation est donc nécessaire pour maintenir des performances équivalentes quelle que soit la nature des objets sur lesquels ceux-ci sont appliqués. S'attachant plus particulièrement, dans l'optique de cette adaptation, à la tâche d'optimisation du paramétrage de ces systèmes, nous proposons dans cet article une méthode originale de ciblage de l'optimisation aux seuls paramètres des opérateurs du système estimés responsables des différentes catégories d'erreurs produites par le système. Cette méthode s'appuie alors sur deux analyses distinctes. La première porte sur les performances du système considéré et permet d'extraire les différentes catégories d'erreur déjà mentionnées. La seconde concerne le fonctionnement des différents opérateurs composant le système et donne lieu à la détermination d'un opérateur responsable pour chaque catégorie d'erreur. Une application de cette méthodologie à un système de détection de texte est par ailleurs détaillée

Le processus de production du risque « submersion marine » en zone littorale : l’exemple des territoires « Xynthia »

Les lourdes conséquences des catastrophes naturelles restent (trop) souvent expliquées, à travers les médias notamment, par les phénomènes de changements climatiques, par la défaillance des systèmes de défense ou par le caractère exceptionnel des conditions naturelles comme ce fut le cas lors des événements de février 2010 « Xynthia ». Or de tels phénomènes de submersion marine ont déjà atteint le littoral atlantique par le passé. Certes les dommages matériels et humains étaient moindres mais les conditions naturelles similaires. La différence se trouve dans l’occupation des sols bien plus tournée vers l’urbanisation ces 50 dernières années. Notre objectif est de montrer que loin d’être le fruit d’un phénomène exceptionnel, la submersion marine issue de la tempête Xynthia est l’aboutissement d’un processus de production du risque massif et récent. L’étude a concerné les communes de Charente-Maritime et Vendée qui ont subi des pertes humaines. La densification de l’urbanisation et plus généralement l’aménagement du territoire, même s’ils ne sont pas à l’origine du phénomène, ont accru les enjeux toujours plus vulnérables dans les zones à risques, accentuant ainsi les conséquences matérielles et humaines des phénomènes naturels. La tempête Xynthia a généré une submersion marine d’occurrence sans doute rare mais qui rencontre des dynamiques territoriales très rapides. Un espace quasi désert peut se retrouver en trente ans fortement urbanisé. Cet exemple rappelle que les mesures de prévention du risque en particulier les mesures de réglementation de l’occupation des sols doivent s’apprécier sur la longue durée car leur transgression est quasiment irréversible.The huge aftermaths of disasters remain (too) often explained, through the media, by the climate change or by the failure of flood defenses, as was the storm Xynthia that hit the western part of France in February 2010. However such phenomena of marine flooding linked to windstorm have already struck the Atlantic coast in the past. Material and human damage were lower although natural conditions were quite similar. The difference lies in the urbanization that has widely grown for fifty years. Our goal is to show that the toll of the Xynthia storm is not essentially due to an exceptional marine flooding phenomenon. On the contrary, it is due to the accumulation of vulnerable assets in flood prone zone. The study mainly relies on the seven communes of Charente-Maritime and Vendée which suffered human losses. The densification of urbanization and more generally the lack of land use control led to an anarchic development of assets at risk especially touristic plants and secondary homes. The marine flooding generated by Xynthia Storm has probably a low return period but the low frequency phenomenon has met very rapid territorial dynamics. Thus the process of “production of risk” had been very fast. A quite uninhabited space can be turned into an highly urbanized territory within thirty years. This example reminds that the measures of prevention of risk, especially land use planning must be taken and assessed on the long term because their transgression is irreversible

Low loss coatings for the VIRGO large mirrors

présentée par L. PinardThe goal of the VIRGO program is to build a giant Michelson type interferometer (3 kilometer long arms) to detect gravitational waves. Large optical components (350 mm in diameter), having extremely low loss at 1064 nm, are needed. Today, the Ion beam Sputtering is the only deposition technique able to produce optical components with such performances. Consequently, a large ion beam sputtering deposition system was built to coat large optics up to 700 mm in diameter. The performances of this coater are described in term of layer uniformity on large scale and optical losses (absorption and scattering characterization). The VIRGO interferometer needs six main mirrors. The first set was ready in June 2002 and its installation is in progress on the VIRGO site (Italy). The optical performances of this first set are discussed. The requirements at 1064 nm are all satisfied. Indeed, the absorption level is close to 1 ppm (part per million), the scattering is lower than 5 ppm and the R.M.S. wavefront of these optics is lower than 8 nm on 150 mm in diameter. Finally, some solutions are proposed to further improve these performances, especially the absorption level (lower than 0.1 ppm) and the mechanical quality factor Q of the mirrors (thermal noise reduction)

The thermo-mechano-chemical twin-screw reactor, a new perspective for the biorefinery of sunflower whole plant: aqueous extraction of oil and other biopolymers, and production of biodegradable fiberboards from cake

Biorefinery of sunflower whole plant was performed successfully using a thermo-mechano-chemical twin-screw reactor. This led to the aqueous extraction of oil and other biopolymers like proteins, pectins and non pectic sugars. It resulted in the overall fractionation of biomass, thus allowing a complete valorization of the input. This biorefinery process was not only efficient but it was also environment-friendly. In addition, it contributed to the production of different end products for various industrial applications. Firstly, the hydrophilic phase will be recycled to the process. Secondly, the densest oil-in-water emulsion is a promising candidate for the formulation of cosmetic creams. Thirdly, the upper hydrophobic phase will be usable for the waterproofing treatment of the surface of agromaterials by coating. Its demixing will also lead to the production of proteins with tensioactive properties. These will serve for the food industry. Lastly, the cake was a mixture of plasticized proteins and lignocellulosic fibers. It was thus considered as a natural composite. Its molding into cohesive fiberboards was conducted successfully using both thermopressing and compression molding processes. The self-bonded boards with high density will be suitable for use as load bearing boards in dry conditions (floor underlayers, interior partitions, furniture, etc.). Positioned in walls and ceilings, boards with medium and low density will contribute to the heat insulation of buildings. In addition, the bulk cake will be also usable as a loose fill insulation material. As proposed, this flow chart thus allows a valorization for all fractions originating from the twin-screw reactor

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Localization and Broadband Follow-Up of the Gravitational-Wave Transient GW150914

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser InterferometerGravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimatesof the time, significance, and sky location of the event were shared with 63 teams of observers covering radio,optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter wedescribe the low-latency analysis of the GW data and present the sky localization of the first observed compactbinary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-rayCoordinates Network circulars, giving an overview of the participating facilities, the GW sky localizationcoverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger,there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadbandcampaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broadcapabilities of the transient astronomy community and the observing strategies that have been developed to pursueneutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-upcampaign are being disseminated in papers by the individual teams