304 research outputs found
Synthesis process of nanowired Al/CuO thermite.
Al/CuO nanothermites were fabricated by thermal oxidation of copper layer at 4501C for 5 hand by aluminum thermal evaporation: thermal evaporation allows producing thin layer less than 2 mminsize. The copper has been deposited by electroplating or thermal evaporation depending on the required thickness. The obtained diameter of Al/CuO nanowiresis 150–250nm. Al/CuO nanowires composite were characterized by scanning electronmicroscopy (SEM), X-raydiffraction (XRD), differential scanning calorimetry (DSC) and differential thermal analysis (DTA). Two distinct exothermicreactions occurred at 515 and 6671C and total energy release of this thermite is 10kJ/cm
Les protéines modulaires : un socle architectural pour la multifonctionnalité.Cas des protéines du complément
Le complément est un système plasmatique qui représente l'élément majeur de la réponseinnée. Son rôle dans l’élimination des pathogènes (bactéries, virus) est bien connu depuis longtempset est induit par la reconnaissance de PAMPs (Pathogen-Associated Molecular Patterns). Enrevanche, la mise en évidence du rôle du complément dans l’élimination des éléments du soi altéréACAMPs (Apoptotic Cell-Associated Molecular Patterns) est beaucoup plus récente.Dans le cas de la lutte contre les pathogènes, le complément génère trois types d'effetsbiologiques synergiques : l'inflammation, la phagocytose et la lyse cellulaire. Dans le cas del’élimination des cellules apoptotiques ou autres cellules du soi modifiées, il induit une élimination« silencieuse » anti-inflammatoire qui contribue au maintien de la tolérance immune. L’ensemble desmécanismes effecteurs liés à l’élimination des corps étrangers est générée par l’activation en cascadede protéases et est finement régulé.On distingue trois voies d’activation du complément en réponse à différents élémentsdéclencheurs, la voie alterne, la voie classique et la voie lectine qui a été découverte plusrécemment, il y a une vingtaine d’années. Le disfonctionnement du système du complément aboutità des maladies inflammatoires et/ou auto-immunes c’est pourquoi la connaissance de sesmécanismes d’action présente à la fois un intérêt fondamental et un intérêt thérapeutique dansdiverses situations pathologiques
Multilayered Al/CuO thermite formation by reactive magnetron sputtering: Nano versus micro
Multilayered Al/CuO thermite was deposited by a dc reactive magnetron sputtering method. Pure Al and Cu targets were used in argon–oxygen gas mixture plasma and with an oxygen partial pressure of 0.13 Pa. The process was designed to produce low stress (<50 MPa) multilayered nanoenergetic material, each layer being in the range of tens nanometer to one micron. The reaction temperature and heat of reaction were measured using differential scanning calorimetry and thermal analysis to compare nanostructured layered materials to microstructured materials. For the nanostructured multilayers, all the energy is released before the Al melting point. In the case of the microstructured samples at least 2/3 of the energy is released at higher temperatures, between 1036 and 1356 K
Toolkit to foster multi-actor research on agrobiodiversity
This toolkit provides building blocks to help create a multi-actor approach to participatory and collaborative plant breeding, and action-research for high quality food systems. It results from the wide range of experience acquired during the Diversifood project to boost cultivated diversity for organic and low-input agriculture and from the collective reflection of all the partners of the project.
The toolkit does not simply provides recipes to apply but illustrates some common prerequisites and traits that emerge in multi-actor projects. In other words, the toolkit proposes strategic «building blocks» to support the successful implementation of the approach. The building blocks have emerged from the feedback provided by Diversifood partners, based on their experiences, as well as from the literature
Toolkit to foster multi-actor research on agrobiodiversity
This toolkit results from a wide range of experience acquired during the Diversifood project to boost cultivated diversity for organic and low-input agriculture and from the collective reflection of all the partners of the project.
It does not simply provide recipes to apply but illustrates some common prerequisites and traits that emerge in such projects. In other words, the toolkit proposes strategic «building blocks» to support the successful implementation of the approach
Specific expression of heme oxygenase-1 by myeloid cells modulates renal ischemia-reperfusion injury
This work was presented in abstract form at the 17th Congress of the European Society for Organ Transplantation (ESOT) in Brussels, Belgium (Brief Oral Presentation, BOS04 – Ischemia, Reperfusion, Metabolism and Aging, abstract N°BO33; 13–16 September 2015) and at the 16th Congress of the European Association of Urology (EAU) in Munich, Germany (Poster Session 48, Kidney Transplant: From Bench to clinical practice, abstract n°603; 11–15 March 2016).Renal ischemia-reperfusion injury (IRI) is a major risk factor for delayed graft function in renal transplantation. Compelling evidence exists that the stress-responsive enzyme, heme oxygenase-1 (HO-1) mediates protection against IRI. However, the role of myeloid HO-1 during IRI remains poorly characterized. Mice with myeloid-restricted deletion of HO-1 (HO-1(M-KO)), littermate (LT), and wild-type (WT) mice were subjected to renal IRI or sham procedures and sacrificed after 24 hours or 7 days. In comparison to LT, HO-1(M-KO) exhibited significant renal histological damage, pro-inflammatory responses and oxidative stress 24 hours after reperfusion. HO-1(M-KO) mice also displayed impaired tubular repair and increased renal fibrosis 7 days after IRI. In WT mice, HO-1 induction with hemin specifically upregulated HO-1 within the CD11b(+) F4/80(lo) subset of the renal myeloid cells. Prior administration of hemin to renal IRI was associated with significant increase of the renal HO-1(+) CD11b(+) F4/80(lo) myeloid cells in comparison to control mice. In contrast, this hemin-mediated protection was abolished in HO-1(M-KO) mice. In conclusion, myeloid HO-1 appears as a critical protective pathway against renal IRI and could be an interesting therapeutic target in renal transplantation.Fonds de la Recherche Scientifique Médicale; Fonds Erasme pour la Recherche Médicale; Société Belge d’Urologie.info:eu-repo/semantics/publishedVersio
PIP30/FAM192A is a novel regulator of the nuclear proteasome activator PA28γ
PA28γ is a nuclear activator of the 20S proteasome involved in the regulation of several essential cellular processes, such as cell proliferation, apoptosis, nuclear dynamics, and cellular stress response. Unlike the 19S regulator of the proteasome, which specifically recognizes ubiquitylated proteins, PA28γ promotes the degradation of several substrates by the proteasome in an ATP- and ubiquitin-independent manner. However, its exact mechanisms of action are unclear and likely involve additional partners that remain to be identified. Here we report the identification of a cofactor of PA28γ, PIP30/FAM192A. PIP30 binds directly and specifically via its C-terminal end and in an interaction stabilized by casein kinase 2 phosphorylation to both free and 20S proteasome-associated PA28γ. Its recruitment to proteasome-containing complexes depends on PA28γ and its expression increases the association of PA28γ with the 20S proteasome in cells. Further dissection of its possible roles shows that PIP30 alters PA28γ-dependent activation of peptide degradation by the 20S proteasome in vitro and negatively controls in cells the presence of PA28γ in Cajal bodies by inhibition of its association with the key Cajal body component coilin. Taken together, our data show that PIP30 deeply affects PA28γ interactions with cellular proteins, including the 20S proteasome, demonstrating that it is an important regulator of PA28γ in cells and thus a new player in the control of the multiple functions of the proteasome within the nucleus
The bacterial cell envelope as delimiter of anti-infective bioavailability - An in vitro permeation model of the Gram-negative bacterial inner membrane.
Gram-negative bacteria possess a unique and complex cell envelope, composed of an inner and outer membrane separated by an intermediate cell wall-containing periplasm. This tripartite structure acts intrinsically as a significant biological barrier, often limiting the permeation of anti-infectives, and so preventing such drugs from reaching their target. Furthermore, identification of the specific permeation-limiting envelope component proves difficult in the case of many anti-infectives, due to the challenges associated with isolation of individual cell envelope structures in bacterial culture. The development of an in vitro permeation model of the Gram-negative inner membrane, prepared by repeated coating of physiologically-relevant phospholipids on Transwell(®) filter inserts, is therefore reported, as a first step in the development of an overall cell envelope model. Characterization and permeability investigations of model compounds as well as anti-infectives confirmed the suitability of the model for quantitative and kinetically-resolved permeability assessment, and additionally confirmed the importance of employing bacteria-specific base materials for more accurate mimicking of the inner membrane lipid composition - both advantages compared to the majority of existing in vitro approaches. Additional incorporation of further elements of the Gram-negative bacterial cell envelope could ultimately facilitate model application as a screening tool in anti-infective drug discovery or formulation development
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