174 research outputs found
Electrospun ZnO/Poly(Vinylidene fluoride-trifluoroethylene) scaffolds for lung tissue engineering
Due to the morbidity and lethality of pulmonary diseases, new biomaterials and scaffolds are needed to support the regeneration of lung tissues, while ideally providing protective effects against inflammation and microbial aggression. In this study, we investigated the potential of nanocomposites of poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] incorporating zinc oxide (ZnO), in the form of electrospun fiber meshes for lung tissue engineering. We focused on their anti-inflammatory, antimicrobial, and mechanoelectrical character according to different fiber mesh textures (i.e., collected at 500 and 4000 rpm) and compositions: (0/100) and (20/80) w/w% ZnO/P(VDF-TrFE), plain and composite, respectively. The scaffolds were characterized in terms of morphological, physicochemical, mechanical, and piezoelectric properties, as well as biological response of A549 alveolar epithelial cells in presence of lung-infecting bacteria. By virtue of ZnO, the composite scaffolds showed a strong anti-inflammatory response in A549 cells, as demonstrated by a significant decrease of interleukin (IL) IL-1a, IL-6, and IL-8 expression in 6 h. In all the scaffold types, but remarkably in the aligned composite ones, transforming growth factor b (TGF-b) and the antimicrobial peptide human b defensin-2 (HBD-2) were significantly increased. The ZnO/P(VDF-TrFE) electrospun fiber meshes hindered the biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa and the cell/scaffold constructs were able to impede S. aureus adhesion and S. aureus and P. aeruginosa invasiveness, independent of the scaffold type. The data obtained suggested that the composite scaffolds showed potential for tunable mechanical properties, in the range of alveolar walls and fibers. Finally, we also showed good piezoelectricity, which is a feature found in elastic and collagen fibers, the main extracellular matrix molecules in lungs. The combination of all these properties makes ZnO/P(VDF-TrFE) fiber meshes promising for lung repair and regeneration
Intelligent non-colorimetric indicators for the perishable supply chain by non-wovens with photo-programmed thermal response
Spoiled perishable products, such as food and drugs exposed to inappropriate temperature, cause million illnesses every year. Risks range from intoxication due to pathogen-contaminated edibles, to suboptimal potency of temperature-sensitive vaccines. High-performance and low-cost indicators are needed, based on conformable materials whose properties change continuously and irreversibly depending on the experienced time-temperature profile. However, these systems can be limited by unclear reading, especially for colour-blind people, and are often difficult to be encoded with a tailored response to detect excess temperature over varying temporal profiles. Here we report on optically-programmed, non-colorimetric indicators based on nano-textured non-wovens encoded by their cross-linking degree. This combination allows a desired time-temperature response to be achieved, to address different perishable products. The devices operate by visual contrast with ambient light, which is explained by backscattering calculations for the complex fibrous material. Optical nanomaterials with photo-encoded thermal properties might establish new design rules for intelligent labels
Discapacidad y Accesibilidad. Reflexiones sobre las barreras en tiempos de distanciamiento social
A partir del aislamiento social de carácter obligatorio dispuesto para todos los habitan-tes del paÃs con el fin de evitar el contagio por el COVID-19 y preservar la vida de las personas como objetivo prioritario, se instala un cambio radical en la rutina en todas las instancias de la vida diaria y, también, en lo personal.En este sentido, las demandas vinculadas a la accesibilidad fÃsica, comunicacional, tecnológica, entre otras, asà como la perspectiva social de la discapacidad que alude a la generación de apoyos y acciones para remover barreras, hoy resultan indispensables ante el análisis crÃtico de cómo se transita la pandemia. ¿Qué escenarios vislumbramos en esta coyuntura particular? ¿Qué medidas y polÃticas podemos identificar en torno al colectivo de personas con discapacidad? ¿Cómo intervienen las organizaciones de las personas con discapacidad en la gestación de estas polÃticas?Nos interesa problematizar estas ideas tanto en el ámbito educativo como social en general, dando cuenta de las acciones, iniciativas, omisiones y experiencias que hemos observado en este tiempo de transitar la pandemia. También, expondremos algunas de las lÃneas de trabajo que como Programa de Discapacidad y Accesibilidad de la Facultad de FilosofÃa y Letras de la Universidad de Buenos Aires hemos llevado adelante.Fil: Fullana, MarÃa Florencia. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras; ArgentinaFil: Gallone, Clara. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras; ArgentinaFil: Heredia, Marina. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras; ArgentinaFil: Liceda, Patricia. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras; ArgentinaFil: Levin, Axel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto de Investigaciones Sociales de América Latina. - Facultad Latinoamericana de Ciencias Sociales. Instituto de Investigaciones Sociales de América Latina; Argentina. Universidad de Buenos Aires; ArgentinaFil: Reznik, LÃa B.. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras; ArgentinaFil: Rusler, Veronica. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras; Argentin
Vitamin D receptor ChIP-seq in primary CD4+ cells: relationship to serum 25-hydroxyvitamin D levels and autoimmune disease
PMCID: PMC3710212This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Bio::Homology::InterologWalk - A Perl module to build putative protein-protein interaction networks through interolog mapping
<p>Abstract</p> <p>Background</p> <p>Protein-protein interaction (PPI) data are widely used to generate network models that aim to describe the relationships between proteins in biological systems. The fidelity and completeness of such networks is primarily limited by the paucity of protein interaction information and by the restriction of most of these data to just a few widely studied experimental organisms. In order to extend the utility of existing PPIs, computational methods can be used that exploit functional conservation between orthologous proteins across taxa to predict putative PPIs or 'interologs'. To date most interolog prediction efforts have been restricted to specific biological domains with fixed underlying data sources and there are no software tools available that provide a generalised framework for 'on-the-fly' interolog prediction.</p> <p>Results</p> <p>We introduce <monospace>Bio::Homology::InterologWalk</monospace>, a Perl module to retrieve, prioritise and visualise putative protein-protein interactions through an orthology-walk method. The module uses orthology and experimental interaction data to generate putative PPIs and optionally collates meta-data into an Interaction Prioritisation Index that can be used to help prioritise interologs for further analysis. We show the application of our interolog prediction method to the genomic interactome of the fruit fly, <it>Drosophila melanogaster</it>. We analyse the resulting interaction networks and show that the method proposes new interactome members and interactions that are candidates for future experimental investigation.</p> <p>Conclusions</p> <p>Our interolog prediction tool employs the Ensembl Perl API and PSICQUIC enabled protein interaction data sources to generate up to date interologs 'on-the-fly'. This represents a significant advance on previous methods for interolog prediction as it allows the use of the latest orthology and protein interaction data for all of the genomes in Ensembl. The module outputs simple text files, making it easy to customise the results by post-processing, allowing the putative PPI datasets to be easily integrated into existing analysis workflows. The <monospace>Bio::Homology::InterologWalk</monospace> module, sample scripts and full documentation are freely available from the Comprehensive Perl Archive Network (CPAN) under the GNU Public license.</p
The ANTARES Optical Beacon System
ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It
consists of a three dimensional array of photomultiplier tubes that can detect
the Cherenkov light induced by charged particles produced in the interactions
of neutrinos with the surrounding medium. High angular resolution can be
achieved, in particular when a muon is produced, provided that the Cherenkov
photons are detected with sufficient timing precision. Considerations of the
intrinsic time uncertainties stemming from the transit time spread in the
photomultiplier tubes and the mechanism of transmission of light in sea water
lead to the conclusion that a relative time accuracy of the order of 0.5 ns is
desirable. Accordingly, different time calibration systems have been developed
for the ANTARES telescope. In this article, a system based on Optical Beacons,
a set of external and well-controlled pulsed light sources located throughout
the detector, is described. This calibration system takes into account the
optical properties of sea water, which is used as the detection volume of the
ANTARES telescope. The design, tests, construction and first results of the two
types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.
- …