Évaluation expérimentale de l'efficacité d'un candidat vaccin sous-unitaire contre le virus respiratoire syncytial bovin

Une étude récente a démontré qu’un candidat vaccin sous unitaire composé d’anneaux formés par la nucléoprotéine recombinante du virus respiratoire syncytial humain (nanoparticules N-SRS) pouvait protéger des souris contre une inoculation d’épreuve (Roux et al., 2008). L’objectif de ce projet était d’évaluer l’efficacité de ce vaccin chez le veau, espèce cible naturelle du virus respiratoire syncytial bovin. Pour cela, 24 veaux séronégatifs vis-à-vis du virus et indemnes d’infection respiratoire ont été divisés en 3 groupes homogènes. Deux des groupes ont été vaccinés deux fois à trois semaines d’intervalle selon deux modalités différentes avec deux formulations différentes du vaccin : une administration intra-musculaire seule ou une administration intramusculaire et intra-nasale. Le troisième groupe constituait le groupe témoin d’animaux non vaccinés. Trois semaines après le rappel, tous les animaux ont été infectés par voie intra-nasale et intra-trachéale avec une souche virulente de VRSB. Les résultats ont montré une protection clinique partielle des veaux vaccinés par rapport aux veaux témoins, en l’absence de protection virologique majeure. Aucune différence n’a été mise en évidence entre les deux modes de vaccination. En conclusion, a vaccination avec les nanoparticules N-SRS a induit une réponse immunitaire spécifique, mais n’a protégé que partiellement les veaux vaccinés contre une infection expérimentale avec le virus respiratoire syncytial bovin. Des études sont en cours pour améliorer l’efficacité vaccinale

Elaboration, by tape casting, of an SOFC half cell for low temperature applications

International audienceThese last past years, a major interest has been devoted to decrease the working temperature of solid oxide fuel cells (SOFCs) down to about 700°C. In this respect, materials with a high ionic conductivity at low temperature have to be found and the rpocess to elaborate fuel cells, using these new materials, has to be developed .....

A new subunit vaccine based on nucleoprotein nanoparticles confers partial clinical and virological protection in calves against bovine respiratory syncytial virus

Human and bovine respiratory syncytial viruses (HRSV and BRSV) are two closely related, worldwide prevalent viruses that are the leading cause of severe airway disease in children and calves, respectively. Efficacy of commercial bovine vaccines needs improvement and no human vaccine is licensed yet. We reported that nasal vaccination with the HRSV nucleoprotein produced as recombinant ringshaped nanoparticles (NSRS) protects mice against a viral challenge with HRSV. The aim of this work was to evaluate this new vaccine that uses a conserved viral antigen, in calves, natural hosts for BRSV. Calves, free of colostral or natural anti-BRSV antibodies, were vaccinated with NSRS either intramuscularly, or both intramuscularly and intranasally using MontanideTM ISA71 and IMS4132 as adjuvants and challenged with BRSV. All vaccinated calves developed anti-N antibodies in blood and nasal secretions and N-specific cellular immunity in local lymph nodes. Clinical monitoring post-challenge demonstrated moderate respiratory pathology with local lung tissue consolidations for the non vaccinated calves that were significantly reduced in the vaccinated calves. Vaccinated calves had lower viral loads than the nonvaccinated control calves. Thus NSRS vaccination in calves provided cross-protective immunity against BRSV infection without adverse inflammatory reaction

Triethyl Citrate (TEC) as a Dispersing Aid in Polylactic Acid/Chitin Nanocomposites Prepared via Liquid-Assisted Extrusion

The production of fully bio-based and biodegradable nanocomposites has gained attention during recent years due to environmental reasons; however, the production of these nanocomposites on the large-scale is challenging. Polylactic acid/chitin nanocrystal (PLA/ChNC) nanocomposites with triethyl citrate (TEC) at varied concentrations (2.5, 5.0, and 7.5 wt %) were prepared using liquid-assisted extrusion. The goal was to find the minimum amount of the TEC plasticizer needed to enhance the ChNC dispersion. The microscopy study showed that the dispersion and distribution of the ChNC into PLA improved with the increasing TEC content. Hence, the nanocomposite with the highest plasticizer content (7.5 wt %) showed the highest optical transparency and improved thermal and mechanical properties compared with its counterpart without the ChNC. Gel permeation chromatography confirmed that the water and ethanol used during the extrusion did not degrade PLA. Further, Fourier transform infrared spectroscopy showed improved interaction between PLA and ChNC through hydrogen bonding when TEC was added. All results confirmed that the plasticizer plays an important role as a dispersing aid in the processing of PLA/ChNC nanocomposites.The authors gratefully acknowledge Bio4Energy, Kempestiftelserna, and Wallenberg Wood Science Center (WWSC) in Sweden for the financial support of this work. We also thank Deodato Radic at the Pontifical Catholic University of Chile (PUC) for supplying the bleached chitin powder and Dipl.-Ing Daniel Schwendemann at IWK University of Applied Sciences Eastern, Switzerland for kindly providing the polylactic acid. The authors also acknowledge Maxime Noel for the technical support with the FTIR and Ph.D. candidate Shiyu Geng for the HR-SEM images

Processing of functional fine scale ceramic structures by ink-jet printing

International audienceThis review illustrates the potentiality of ink-jet printing for the fabrication of functional fine scale ceramic structures corresponding to two different kinds of micro-pillar arrays i.e. (i) PZT skeletons, etc..

REMEDIOS MESA DE LEÓN [Material gráfico]

ÁLBUM FAMILIAR CASA DE COLÓNCopia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Enhanced Electrocaloric Response of Vinylidene Fluoride–Based Polymers via One‐Step Molecular Engineering

Electrocaloric refrigeration is one of the most promising environmentally-friendly technologies to replace current cooling platforms—if a notable electrocaloric effect (ECE) is realized around room temperature where the highest need is. Here, a straight-forward, one-pot chemical modification of P(VDF-ter-TrFE-ter-CTFE) is reported through the controlled introduction of small fractions of double bonds within the backbone that, very uniquely, decreases the lamellar crystalline thickness while, simultaneously, enlarging the crystalline coherence along the a-b plane. This increases the polarizability and polarization without affecting the degree of crystallinity or amending the crystal unit cell—undesirable effects observed with other approaches. Specifically, the permittivity increases by >35%, from 52 to 71 at 1 kHz, and ECE improves by >60% at moderate electric fields. At 40 °C, an adiabatic temperature change >2 K is realized at 60 MV m−1 (>5.5 K at 192 MV m−1), compared to ≈1.3 K for pristine P(VDF-ter-TrFE-ter-CTFE), highlighting the promise of a simple, versatile approach that allows direct film deposition without requiring any post-treatment such as mechanical stretching or high-temperature annealing for achieving the desired performance

Electroactive poly(vinylidene fluoride) based materials: recent progress, challenges and opportunities

A poly(vinylidene fluoride) (PVDF) and its copolymers are polymers that, in specific crystalline phases, show high dielectric and piezoelectric values, excellent mechanical behavior and good thermal and chemical stability, suitable for many applications from the biomedical area to energy devices. This chapter introduces the main properties, processability and polymorphism of PVDF. Further, the recent advances in the applications based on those materials are presented and discussed. Thus, it shown the key role of PVDF and its copolymers as smart and multifunctional material, expanding the limits of polymer-based technologies.FCT (Fundação para a Ciência e Tecnologia) for financial support under the framework of Strategic Funding grants UID/FIS/04650/2019, and UID/QUI/0686/2019 and project PTDC/FIS-MAC/28157/2017, PTDC/BTMMAT/28237/2017, PTDC/EMD-EMD/28159/2017. The author also thanks the FCT for financial support under grant SFRH/BPD/112547/2015 (C.M.C.), SFRH/BPD/98109/2013 (V.F.C.), SFRH/BD/140698/2018 (R.B.P.), SFRH/BPD/96227/2013 (P.M.), SFRH/BPD/121526/2016 (D.M.C.), SFRH/BPD/97739/2013 (V. C.), SFRH/BPD/90870/2012 (C.R.). Financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) through project MAT2016-76039-C4-3-R (AEI/FEDER, UE) (including FEDER financial support) and from the Basque Government Industry and Education Departments under the ELKARTEK, HAZITEK and PIBA (PIBA-2018-06)