Kinetic of biobased bitumen synthesis from microalgae biomass by hydrothermal liquefaction

The current worldwide consumption of bitumen is about 100 million tons. A remarkable combination of properties (adhesion, impermeability to water, specific thermo-rheological behavior) makes it a key material in road construction. Today’s bitumen is mostly obtained from petroleum refining, so bioabased alternatives have to be explored for the future. The ALGOROUTE project funded by the French National Agency for Research (ANR) focuses on the use of hydrothermal liquefaction (HTL) process for the production of bitumen mimicking binders from microalgae biomass. HTL applied to microalgae is inspired by the geological process of petroleum formation, but on a very short time scale: For conditions around 260 °C / 50 bar, bitumen like products have been obtained by our consortium for residence times of about 1 hour [1] [2]. Beside temperature and pressure, the key parameters are the reaction time, algae/water ratio and loading level of reactor. Please click Additional Files below to see the full abstract

Identification de la conductivité thermique d'un polymère semi-cristallin en exploitant la mesure de température au c ur d'une pièce moulée par injection

La conductivité thermique des matériaux polymères est un paramètre déterminant pour l'étude de l'influence de la mise en uvre sur l'évolution des propriétés mécaniques des objets moulés. L'objectif de ce travail est d'identifier la conductivité thermique d'un polymère semi-cristallin en exploitant les mesures de température au c ur d'une pièce moulée par injection. La méthode adoptée est basée sur un calcul inverse par recalage éléments finis. Les résultats obtenus sont comparés aux mesures expérimentales obtenues par conductivimètre

A Soluble Form of the Triggering Receptor Expressed on Myeloid Cells-1 Modulates the Inflammatory Response in Murine Sepsis

The triggering receptor expressed on myeloid cells (TREM)-1 is a recently discovered receptor expressed on the surface of neutrophils and a subset of monocytes. Engagement of TREM-1 has been reported to trigger the synthesis of proinflammatory cytokines in the presence of microbial products. Previously, we have identified a soluble form of TREM-1 (sTREM-1) and observed significant levels in serum samples from septic shock patients but not controls. Here, we investigated its putative role in the modulation of inflammation during sepsis. We observed that sTREM-1 was secreted by monocytes activated in vitro by LPS and in the serum of animals involved in an experimental model of septic shock. Both in vitro and in vivo, a synthetic peptide mimicking a short highly conserved domain of sTREM-1 appeared to attenuate cytokine production by human monocytes and protect septic animals from hyper-responsiveness and death. This peptide seemed to be efficient not only in preventing but also in down-modulating the deleterious effects of proinflammatory cytokines. These data suggest that in vivo modulation of TREM-1 by sTREM peptide might be a suitable therapeutic tool for the treatment of sepsis

Détermination de la répartition spatiale optimale des sources thermiques dans un plateau chauffant

International audienceDans ce travail, on s'intéresse à l'optimisation du chauffage d'un outillage (plateau chauffant) utilisé dans la mise en forme de matériaux composites à hautes températures (~400°C). L'objectif recherché est d'assurer la maîtrise du champ de température en tout point à la surface de l'outillage qui doit reproduire un champ consigne donné afin de chauffer un moule ayant une forme complexe. Pour ce faire, une procédure a été mise en place afin de déterminer la répartition spatiale optimale des sources thermiques de chauffage. La démarche proposée comporte deux étapes : (i) la définition d'une courbe paramétrée qui définit la répartition spatiale des sources de chauffage dans l'épaisseur du plateau chauffant et (ii) l'utilisation d'une méthode inverse couplant un algorithme d'optimisation stochastique avec un code de calcul par éléments finis. Cette deuxième étape permet d'ajuster cette courbe afin d'obtenir un champ de température simulé le plus proche possible de celui voulu à la surface du plateau. On étudie l'évolution de cet écart entre les champs de température ainsi que la consommation énergétique en fonction du nombre de sources retenu. Nomenclature (11 points, 2 colonnes) H Hauteur (m) Valeur maximale de (°C) L Largeur (m) Température normalisée entre [0,1] et Paramètres de la courbe à optimiser Courbe paramétrée Température consigne (°C) Ecart quadratique moyen (°C) Valeur minimale de (°C

255 In vivo detection of non-occlusive thrombi in drug-eluting stents by scintigraphy and radio-labelled annexin V in a rabbit model

IntroductionThrombi in contact with non re-endothelialized stent struts associated with drug-eluting stent (DES) thrombosis. Hence, detection of thrombi in DES could help to evaluate the risk of DES thrombosis. Annexin V radio-labelled with 99mTechnetium (99mTc) is a radio-tracer with a high affinity for activated platelets.ObjectivesOur objectives were: 1) to develop an animal model of non-occlusive thrombosis of stents, 2) to evaluate the ability of annexin V 99mTc for the detection of in-stent thrombi using scintigraphy.MethodsRight carotid arteries of NZW rabbits (n=14) fed a high cholesterol diet were implanted with overlapping DES (n=7) or bare-metal stents (BMS; n=7). Four weeks after stent implantation, rabbits underwent a first scintigraphy 3 hours after injection of 200 MBq of radio-labelled annexin V 99mTc. At the end of the first scintigraphy, a suture was placed surgically proximal to the stented carotid arteries in order to induce a thrombus-prone flow limiting stenosis. Four days later, a second scintigraphy was performed. After the second scintigraphy, stents were excised, imaged ex vivo and then fixed for histological examination and scanning electron microscopy (SEM).ResultsActivities measured in vivo in the stented carotid arteries after injection of annexin V 99mTc were higher on the second scintigraphy after creation of a surgical stenosis as compared to the first scintigraphy (0.24 vs. 0.15 counts/pixel/MBq, respectively; p<0.05). On the second scintigraphy, activities were higher in DES vs. BMS (0.26 vs. 0.19 counts/pixel/MBq, respectively; p < 0.005). High activities measured in stents in vivo were associated with the detection of thrombi on corresponding histological sections and SEM.ConclusionsIn this work, we developed a rabbit model of non-occlusive thrombosis of stents in carotid arteries. In this model, in-stent thrombi could be detected using annexin V 99mTc scintigraphy

Autistic Disorder in Patients with Williams-Beuren Syndrome: A Reconsideration of the Williams-Beuren Syndrome Phenotype

Abstract Background: Williams-Beuren syndrome (WBS), a rare developmental disorder caused by deletion of contiguous genes at 7q11.23, has been characterized by strengths in socialization (overfriendliness) and communication (excessive talkativeness). WBS has been often considered as the polar opposite behavioral phenotype to autism. Our objective was to better understand the range of phenotypic expression in WBS and the relationship between WBS and autistic disorder

Non-Invasive Molecular Imaging of Fibrosis Using a Collagen-Targeted Peptidomimetic of the Platelet Collagen Receptor Glycoprotein VI

Background: Fibrosis, which is characterized by the pathological accumulation of collagen, is recognized as an important feature of many chronic diseases, and as such, constitutes an enormous health burden. We need non-invasive specific methods for the early diagnosis and follow-up of fibrosis in various disorders. Collagen targeting molecules are therefore of interest for potential in vivo imaging of fibrosis. In this study, we developed a collagen-specific probe using a new approach that takes advantage of the inherent specificity of Glycoprotein VI (GPVI), the main platelet receptor for collagens I and III. Methodology/Principal: Findings An anti-GPVI antibody that neutralizes collagen-binding was used to screen a bacterial random peptide library. A cyclic motif was identified, and the corresponding peptide (designated collagelin) was synthesized. Solid-phase binding assays and histochemical analysis showed that collagelin specifically bound to collagen (Kd 10−7 M) in vitro, and labelled collagen fibers ex vivo on sections of rat aorta and rat tail. Collagelin is therefore a new specific probe for collagen. The suitability of collagelin as an in vivo probe was tested in a rat model of healed myocardial infarctions (MI). Injecting Tc-99m-labelled collagelin and scintigraphic imaging showed that uptake of the probe occurred in the cardiac area of rats with MI, but not in controls. Post mortem autoradiography and histological analysis of heart sections showed that the labeled areas coincided with fibrosis. Scintigraphic molecular imaging with collagelin provides high resolution, and good contrast between the fibrotic scars and healthy tissues. The capacity of collagelin to image fibrosis in vivo was confirmed in a mouse model of lung fibrosis. Conclusion/Significance: Collagelin is a new collagen-targeting agent which may be useful for non-invasive detection of fibrosis in a broad spectrum of diseases.Psycholog

Autistic Disorder in Patients with Williams-Beuren Syndrome: A Reconsideration of the Williams-Beuren Syndrome Phenotype

International audienceBackground: Williams-Beuren syndrome (WBS), a rare developmental disorder caused by deletion of contiguous genes at 7q11.23, has been characterized by strengths in socialization (overfriendliness) and communication (excessive talkativeness). WBS has been often considered as the polar opposite behavioral phenotype to autism. Our objective was to better understand the range of phenotypic expression in WBS and the relationship between WBS and autistic disorder. Methodology: The study was conducted on 9 French individuals aged from 4 to 37 years old with autistic disorder associated with WBS. Behavioral assessments were performed using Autism Diagnostic Interview-Revised (ADI-R) and Autism Diagnostic Observation Schedule (ADOS) scales. Molecular characterization of the WBS critical region was performed by FISH. Findings: FISH analysis indicated that all 9 patients displayed the common WBS deletion. All 9 patients met ADI-R and ADOS diagnostic criteria for autism, displaying stereotypies and severe impairments in social interaction and communication (including the absence of expressive language). Additionally, patients showed improvement in social communication over time. Conclusions: The results indicate that comorbid autism and WBS is more frequent than expected and suggest that the common WBS deletion can result in a continuum of social communication impairment, ranging from excessive talkativeness and overfriendliness to absence of verbal language and poor social relationships. Appreciation of the possible co-occurrence of WBS and autism challenges the common view that WBS represents the opposite behavioral phenotype of autism, and might lead to improved recognition of WBS in individuals diagnosed with autism