1,113 research outputs found

    Comportamiento de la temperatura de trabajo de un lubricante mineral utilizando aceite de ricino como aditivo

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    En aplicaciones automotrices, los lubricantes deben presentar alta adherencia a superficies metálicas para protección ante altas velocidades de trabajo. Actualmente la literatura presenta la posibilidad de utilizar aceite de ricino, como aditivo para favorecer la untuosidad y adherencia de lubricantes minerales, cuando estos se someten a altas revoluciones. El objetivo del presente trabajo busca analizar el comportamiento de la temperatura en un cojinete de deslizamiento, utilizando lubricante SAE 40 y mezclas con aceite de ricino, bajo una condición de carga y velocidad. Los resultados fueron obtenidos para mezclas con 1,5,10 y 25% de aceite dericino, demostrando un comportamiento estable ante las condiciones de trabajo

    Comportamiento de la temperatura de trabajo de un lubricante mineral utilizando aceite de ricino como aditivo

    Get PDF
    En aplicaciones automotrices, los lubricantes deben presentar alta adherencia a superficies metálicas para protección ante altas velocidades de trabajo. Actualmente la literatura presenta la posibilidad de utilizar aceite de ricino, como aditivo para favorecer la untuosidad y adherencia de lubricantes minerales, cuando estos se someten a altas revoluciones. El objetivo del presente trabajo busca analizar el comportamiento de la temperatura en un cojinete de deslizamiento, utilizando lubricante SAE 40 y mezclas con aceite de ricino, bajo una condición de carga y velocidad. Los resultados fueron obtenidos para mezclas con 1,5,10 y 25% de aceite dericino, demostrando un comportamiento estable ante las condiciones de trabajo

    Inkjet‐Printed p‐NiO/n‐ZnO Heterojunction Diodes for Photodetection Applications

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    Transparent Conducting Oxides (TCOs) are an enticing family of optoelectronic materials which have been proven to increase efficiency when incorporated into perovskite light emitting diode (PE-LED) and organic OLED architectures as transport layers. Solution-processed metal oxide inks have already been demonstrated, although there is still a need for high-quality inkjet-printable metal oxide inks with a thermal post-process below 200 °C. The set of inks in this work are adapted from low-boiling point colloidal suspensions of metal oxide nanoparticles synthesized via flame spray pyrolysis. High quality, pinhole- and wrinkle-free inkjet-printed layers are obtained at low temperatures through vacuum oven post process, as proven by scanning electron microscopy. The crystallinity of the layers is confirmed by X-ray diffraction, showing the expected hexagonal and cubic structures respectively for ZnO and NiO. The thin film layers reach over 70% (ZnO) and 90% (NiO) transparency in the visible spectrum. Their implementation in the inkjet-printed p-n diode shows excellent I-V rectifying behavior with an ON/OFF ratio of two orders of magnitude at ±3 V and a forward threshold voltage of 2 V. Furthermore, the device exhibits an increase in photocurrent around four orders of magnitude when illuminated under a 1-sun solar simulator

    Mycobacterial surface characters remodeled by growth conditions drive different tumor-infiltrating cells and systemic IFN-gamma/IL-17 release in bladder cancer treatment

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    The mechanism of action of intravesical Mycobacterium bovis BCG immunotherapy treatment for bladder cancer is not completely known, leading to misinterpretation of BCG-unresponsive patients, who have scarce further therapeutic options. BCG is grown under diverse culture conditions worldwide, which can impact the antitumor effect of BCG strains and could be a key parameter of treatment success. Here, BCG and the nonpathogenic Mycobacterium brumae were grown in four culture media currently used by research laboratories and BCG manufacturers: Sauton-A60, -G15 and -G60 and Middlebrook 7H10, and used as therapies in the orthotopic murine BC model. Our data reveal that each mycobacterium requires specific culture conditions to induce an effective antitumor response. since higher survival rates of tumor-bearing mice were achieved using M. brumae-A60 and BCG-G15 than the rest of the treatments. M. brumae-A60 was the most efficacious among all tested treatments in terms of mouse survival, cytotoxic activity of splenocytes against tumor cells, higher systemic production of IL-17 and IFN-gamma, and bladder infiltration of selected immune cells such as ILCs and CD4(TEM). BCG-G15 triggered an antitumor activity based on a massive infiltration of immune cells, mainly CD3(+) (CD4(+) and CD8(+)) T cells, together with high systemic IFN-gamma release. Finally, a reduced variety of lipids was strikingly observed in the outermost layer of M. brumae-A60 and BCG-G15 compared to the rest of the cultures, suggesting an influence on the antitumor immune response triggered. These findings contribute to understand how mycobacteria create an adequate niche to help the host subvert immunosuppressive tumor actions

    VEGF Gene Expression in Adult Human Thymus Fat: A Correlative Study with Hypoxic Induced Factor and Cyclooxigenase-2

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    UNLABELLED:It is well known that the adult human thymus degenerates into fat tissue; however, it has never been considered as a potential source of angiogenic factors. Recently, we have described that this fat (TAT) produces angiogenic factors and induces human endothelial cell proliferation and migration, indicating its potential angiogenic properties. DESIGN:Adult thymus fat and subcutaneous adipose tissue specimens were obtained from 28 patients undergoing cardiac surgery, making this tissue readily available as a prime source of adipose tissue. We focused our investigation on determining VEGF gene expression and characterizing the different genes, mediators of inflammation and adipogenesis, and which are known to play a relevant role in angiogenesis regulation. RESULTS:We found that VEGF-A was the isoform most expressed in TAT. This expression was accompanied by an upregulation of HIF-1alpha, COX-2 and HO-1 proteins, and by increased HIF-1 DNA binding activity, compared to SAT. Furthermore, we observed that TAT contains a high percentage of mature adipocytes, 0.25% of macrophage cells, 15% of endothelial cells and a very low percentage of thymocyte cells, suggesting the cellular variability of TAT, which could explain the differences in gene expression observed in TAT. Subsequently, we showed that the expression of genes known as adipogenic mediators, including PPARgamma1/gamma2, FABP-4 and adiponectin was similar in both TAT and SAT. Moreover the expression of these latter genes presented a significantly positive correlation with VEGF, suggesting the potential association between VEGF and the generation of adipose tissue in adult thymus. CONCLUSION:Here we suggest that this fat has a potential angiogenic function related to ongoing adipogenesis, which substitutes immune functions within the adult thymus. The expression of VEGF seems to be associated with COX-2, HO-1 and adipogenesis related genes, suggesting the importance that this new fat has acquired in research in relation to adipogenesis and angiogenesis

    Molecular and evolutionary basis of O-antigenic polysaccharide driven phage sensitivity in environmental pseudomonads

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    Pseudomonas protegens CHA0, a bacterial strain able to suppress plant pathogens as well as efficiently kill lepidopteran pest insects, has been studied as biocontrol agent to prevent ensuing agricultural damage. However, the success of this method is dependent on the efficient plant colonization by the bacterial inoculant while it faces competition from the resident microbiota as well as predators such as bacteriophages. One of these naturally occurring phages, ΦGP100, was found to drastically reduce the abundance of CHA0 once inoculated into plant microcosms, resulting in the loss of plant protection against a phytopathogen. Here, we investigated the molecular determinants implicated in the interaction between CHA0 and the phage ΦGP100 using a high-density transposon-sequencing approach. We show that lipopolysaccharide cell surface decorations, specifically the longer OBC3-type O-antigenic polysaccharide (O-PS, O-antigen) of the two dominant O-PS of CHA0 is essential for the attachment and infection of ΦGP100. Moreover, when exploring the distribution of the OBC3 cluster in bacterial genomes, we identified several parts of this gene cluster that are conserved in phylogenetically distant bacteria. Through heterologous complementation, we integrated an OBC3-type gene copy from a phylogenetically distant bacterium and were able to restore the phage sensitivity of a CHA0 mutant which lacked the ability to form long O-PS. Finally, we evidence that the OBC3 gene cluster of CHA0 displays a high genomic plasticity and likely underwent several horizontal acquisitions and genomic rearrangements. Collectively, this study underlines the complexity of phage-bacteria interaction and the multifunctional aspect of bacterial cell surface decorations
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