24,440 research outputs found

    Mouse model of Schistosomiasis: infection with Schistosoma mansoni in CD-1 mice

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    Schistosomiasis is a parasitic disease that affects almost 240 million worldwide. CD1 mice were infected with cercariae of S. mansoni, after which infection developed for 8 weeks. Tissues were processed to immuno-histological techniques. It was performed H&E staining for overall analyses, Sirius Red for fibrosis and immunohistochemistry for inflammation biomarkers. The most infected organ was the liver, fibrosis decreased with egg development and Galectin-3 (Gal3) and Interleukin 6 (IL-6) were expressed inside granulomasThis work was also supported by FCT – Fundação para a Ciência e Tecnologia (REF UID/BIM/04293/2013) and by the project NORTE-01-0145-FEDER-000012 and by a scholarship to Carla Luís with the reference SAICT2016/FEDER/BIO4DIA/BTI under the supervision of Dr. Rúben Fernandes.N/

    On the Modeling of Droplet Evaporation on Superhydrophobic Surfaces

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    When a drop of water is placed on a rough surface, there are two possible extreme regimes of wetting: the one called Cassie-Baxter (CB) with air pockets trapped underneath the droplet and the one characterized by the homogeneous wetting of the surface, called the Wenzel (W) state. A way to investigate the transition between these two states is by means of evaporation experiments, in which the droplet starts in a CB state and, as its volume decreases, penetrates the surface's grooves, reaching a W state. Here we present a theoretical model based on the global interfacial energies for CB and W states that allows us to predict the thermodynamic wetting state of the droplet for a given volume and surface texture. We first analyze the influence of the surface geometric parameters on the droplet's final wetting state with constant volume, and show that it depends strongly on the surface texture. We then vary the volume of the droplet keeping fixed the geometric surface parameters to mimic evaporation and show that the drop experiences a transition from the CB to the W state when its volume reduces, as observed in experiments. To investigate the dependency of the wetting state on the initial state of the droplet, we implement a cellular Potts model in three dimensions. Simulations show a very good agreement with theory when the initial state is W, but it disagrees when the droplet is initialized in a CB state, in accordance with previous observations which show that the CB state is metastable in many cases. Both simulations and theoretical model can be modified to study other types of surface.Comment: 23 pages, 7 figure

    Superlens made of a metamaterial with extreme effective parameters

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    We propose a superlens formed by an ultra-dense array of crossed metallic wires. It is demonstrated that due to the anomalous interaction between crossed wires, the structured substrate is characterized by an anomalously high index of refraction and supports strongly confined guided modes with very short propagation wavelengths. It is theoretically proven that a planar slab of such structured material makes a superlens that may compensate for the attenuation introduced by free-space propagation and restore the subwavelength details of the source. The bandwidth of the proposed device can be quite significant since the response of the structured substrate is non-resonant. The theoretical results are fully supported by numerical simulations.Comment: Accepted for publication in Phys. Rev. B (in press

    FM 047-02: a collisional pair of galaxies with a ring

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    Aims. We investigate the nature of the galaxy pair FM 047-02, which has been proposed as an archetype of the Solitaire types of peculiar (collisional) ring galaxies. Methods. The study is based on long-slit spectrophotometric data in the range of 3500-9500 angstrons obtained with the Gemini Multi-ObjectComment: 07 pages, 06 figures, 02 tables. arXiv admin note: text overlap with arXiv:1206.071

    Detection of new eruptions in the Magellanic Clouds LBVs R 40 and R 110

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    We performed a spectroscopic and photometric analysis to study new eruptions in two luminous blue variables (LBVs) in the Magellanic Clouds. We detected a strong new eruption in the LBV R40 that reached V9.2V \sim 9.2 in 2016, which is around 1.31.3 mag brighter than the minimum registered in 1985. During this new eruption, the star changed from an A-type to a late F-type spectrum. Based on photometric and spectroscopic empirical calibrations and synthetic spectral modeling, we determine that R\,40 reached Teff=58006300T_{\mathrm{eff}} = 5800-6300~K during this new eruption. This object is thereby probably one of the coolest identified LBVs. We could also identify an enrichment of nitrogen and r- and s-process elements. We detected a weak eruption in the LBV R 110 with a maximum of V9.9V \sim 9.9 mag in 2011, that is, around 1.01.0 mag brighter than in the quiescent phase. On the other hand, this new eruption is about 0.20.2 mag fainter than the first eruption detected in 1990, but the temperature did not decrease below 8500 K. Spitzer spectra show indications of cool dust in the circumstellar environment of both stars, but no hot or warm dust was present, except by the probable presence of PAHs in R\,110. We also discuss a possible post-red supergiant nature for both stars
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