2,456 research outputs found
Información bibliográfica en tiempo real para el tratamiento de enfermedades: desarrollo de una interfaz gráfica optimizada para dispositivos móviles
El propósito del presente trabajo fue desarrollar una interfaz gráfica optimizada para dispositivos móviles
(Plataforma Móvil) que permita obtener información actualizada, especializada y en tiempo real sobre terapéutica de diversas patologías y enfermedades.Facultad de Ciencias Médica
Sinking of light intruders in a shaken granular bed
We present an experimental study of the displacement of a light intruder immersed in a vibrated granular
bed. Using high speed video we resolve the motion, during one cycle of oscillation, of a cylindrical object
inside a Plexiglas box partially filled with grains. We report experimental evidence that, in the absence of
convection, at least two forces are behind the intruder’s motion: an air drag force—due to the airflow through
the granular bed—and a buoyancy force produced by an air-mediated granular fluid
A Scoping Review on Virtual Reality-Based Industrial Training
The fourth industrial revolution has forced most companies to technologically evolve, applying new digital tools, so that their workers can have the necessary skills to face changing work environments. This article presents a scoping review of the literature on virtual reality-based training systems. The methodology consisted of four steps, which pose research questions, document search, paper selection, and data extraction. From a total of 350 peer-reviewed database articles, such as SpringerLink, IEEEXplore, MDPI, Scopus, and ACM, 44 were eventually chosen, mostly using the virtual reality haptic glasses and controls from Oculus Rift and HTC VIVE. It was concluded that, among the advantages of using this digital tool in the industry, is the commitment, speed, measurability, preservation of the integrity of the workers, customization, and cost reduction. Even though several research gaps were found, virtual reality is presented as a present and future alternative for the efficient training of human resources in the industrial field.This work was supported by Instituto Superior Tecnológico Victoria Vásconez Cuvi. The authors appreciate the opportunity to analyze topics related to this paper. The authors must also recognize the supported bringing by Universidad Tecnica de Ambato (UTA) and their Research and Development Department (DIDE) under project CONIN-P-256-2019, and SENESCYT by grants “Convocatoria Abierta 2011” and “Convocatoria Abierta 2013”
The cosmic shallows I: interaction of CMB photons in extended galaxy halos
We report and analyse the presence of foregrounds in the cosmic microwave
background (CMB) radiation associated to extended galactic halos. Using the
cross correlation of Planck and WMAP maps and the 2MRS galaxy catalogue, we
find that the mean temperature radial profiles around nearby galaxies at show a statistically significant systematic decrease of
extending up to several galaxy radii. This effect strongly
depends on the galaxy morphological type at scales within several tens of times
the galaxy size, becoming nearly independent of galaxy morphology at larger
scales. The effect is significantly stronger for the more extended galaxies,
with galaxy clustering having a large impact on the results. Our findings
indicate the presence of statistically relevant foregrounds in the CMB maps
that should be considered in detailed cosmological studies. Besides, we argue
that these can be used to explore the intergalactic medium surrounding bright
late-type galaxies and allow for diverse astrophysical analyses.Comment: 10 pages, 9 figures, submitted to MNRA
V12 248. Reemplazo de raíz de aorta según técnica de david y de arco aórtico con injerto trifurcado, en un paciente diagnosticado de síndrome de loeys-dietz
IntroducciónSe describe la técnica quirúrgica de un paciente de 24 años de edad con síndrome de Loeys-Dietz. Se trata de una enfermedad hereditaria del tejido conectivo producida por la mutación del gen del receptor del factor de crecimiento transformante (TGF)-β;. Su característica principal y condicionante del pronóstico es la dilatación del sistema vascular, principalmente la aorta.MétodoEl paciente presentaba dilatación aneurismática de la raíz y del arco aórtico, con un diámetro máximo de 50 mm. Tenía además historia familiar de muerte súbita de origen cardíaco en tres familiares de primer grado a edades tempranas. Ante la indicación de tratamiento quirúrgico se procedió a realizar sustitución de los segmentos aneurismáticos. En la raíz aórtica se realizó técnica de preservación valvular (técnica de David, modificación de Miller). La sustitución del arco aórtico se llevó a cabo mediante interposición de injerto trifurcado, en hipotermia moderada y con perfusión cerebral anterógrada.Resultado y conclusionesNo hubo complicaciones postoperatorias. El tratamiento quirúrgico precoz en los pacientes afectos de síndrome de Loeys-Dietz es imprescindible. La experiencia acumulada hasta el momento revela la agresividad de esta enfermedad. Por ello, es necesario un abordaje completo cuando existe afectación a distintos niveles. El empleo de técnicas de preservación valvular permite además disminuir la morbimortalidad asociada a las prótesis valvulares
Glucocorticoid receptor intestinal epithelial knockout mice show attenuated colonic inflammatory response but unaffected permeability in early experimental sepsis
Introduction: Sepsis is defined as an organic dysfunction that threatens the life of patients due to an abnormally regulated response to infection [1]. The initial phase of sepsis is dominated by an increased production of proinflammatory cytokines, which leads to augmented capillary permeability, extravasation, hypercoagulability and myelopoiesis. One of the main sources of infection in sepsis is believed to be the intestinal microbiota via traslocation through the mucosa to the bloodstream. Systemic inflammation weakens intestinal barrier function (IBF) in animal models, resulting in increased bacterial traslocation [2]. Even if the management of sepsis has advanced in the last decades, mortality is still high and there are blanks in terms of pathological systems and long-term consequences. Thus, the search for effective treatments is clearly justified. Glucocorticoids (GC) are part of the drugs used in sepsis, but they have only shown a moderate therapeutic effect. This fact may be caused by harmful effects of GCs on IBF, whose compromise may limit GC clinical benefit by facilitating luminal translocation of microorganisms. Besides, GC treatment impairs epithelial healing in experimental colitis in mice [3]. Previous results of our research group have shown that mice with induced deletion of the GC receptor (GR) in intestinal epithelial cells (i.e. NR3C1ΔIEC mice) are protected against dextran sulphate sodium (DSS)-induced colitis [4]. In turn, gene deletion results in a short lived inflammatory response in the colon [5].
Objective: Understanding the role of the intestinal epithelial GR and its involvement in IBF regulation in experimental sepsis, with the ultimate goal of improving the management of sepsis with GCs.
Matherial and methods: The cecal ligation and puncture (CLP) model of sepsis was applied to WT C57BL/6J and NR3C1ΔIEC mice. Ceacum-exposed mice were used as control (Sham). Mice were sacrificed 24 hours after surgery. Four hours before sacrifice, mice were administered
4 kD FITC-dextran, a fluorescent marker of permeability. Colon, jejunum, adrenes, kidney and liver RT-qPCRs were performed as well as determination of plasma FITC-dextran and corticosterone plasma levels.
Results: After 24 h, CLP mice exhibited elevated corticosterone plasma levels with hypoglycemia and splenomegaly. Intestinal barrier function was weakened, as indicated by increased FITC-dextran plasma levels. A modest increase in inflammatory markers (S100a8, Cxcl1) was noted in the colon and jejunum. The expression of Tjp1, involved in barrier function, was downregulated in CLP mice. Similarly, the colonic expression of Cyp11a1 and Lrh1, involved in local steroidogenesis, was lower in CLP mice, regardless of genotype. Markers of inflammation were also augmented in the lung and kidney. CLP mice exhibited hypercorticosteronemia, which was associated to increased Cyp11a1 in the adrenes. Of note, both parameters were less pronounced in KO mice. The latter also exhibited dampened inflammatory response in the colon but not the jejunum. FITC-dextran plasma levels were similarly increased in WT and KO mice.
Conclusions: In the early stages of the CLP model of sepsis the colon and jejunum are inflamed, and epithelial deletion of the glucocorticoid receptor appears to modulate inflammation in the former, with no change in barrier function. Further studies will characterize the microbiota composition and phenotype in later stages and in the response to glucocorticoid treatment
Effect of band-filling and structural distortions on the Curie temperature of Fe-Mo double perovkites
By means of high resolution neutron powder diffraction at low temperature we
have characterized the structural details of
() and () series of compounds. This study reveals a similar variation of the mean
bond-angle \FeOMo in both series. In contrast, the mean bond-distance \FeMoO\
increases with La but not with Ca substitution. Both series also present a
different evolution of the Curie temperature (), which raises in the La
series and slightly decreases in the Ca one. We thus conclude that the
enhancement of in the La series is due to the electron filling of the
conduction band and a concomitant rising of the density of states at the Fermi
level.Comment: Revtex, 4 Journal pages, 2 figures, 1 tabl
Design and study of a photo-switchable polymeric system in the presence of ZnS nanoparticles under the influence of UV light irradiation
Recent progress in the field of photosensitive materials has prompted a need to develop efficient methods to synthesize materials with basic intermolecular architectural designs and novel properties. Accordingly, in this work we design and study a photoactive polymer as a photo-switchable polymeric system in the presence and absence of ZnS nanoparticles (average size < 10 nm) at 5 wt.%. The influence of UV light irradiation on its properties were also studied. The photoactive block copolymer was obtained from styrene (S) and methyl methacrylate (MMA) as monomers and 1-(2-hydroxyethyl)-3,3-dimethylindoline-6-nitrobenzopyran (SP) was grafted to the block copolymer backbone as a photochromic agent. Furthermore, the incorporation of ZnS (NPs) as photo-optical switch component into the system enhances the purple colored photo-emission, with the open form of the spiropyran derivative (merocyanine, MC). The ZnS stabilize the isomeric equilibrium in the MC interconversion of the photochromic agent. The photo-switchable properties of the PS-b-PMMA-SP in the presence of ZnS (NPs) were examined using UV-VIS spectroscopy, Photoluminescence (PL) spectroscopy, optical fluorescence and scanning electronic microscopy (SEM-EDX.). The observed changes in the absorbance, fluorescence and morphology of the system were associated to the reversible interconversion of the two states of the photochromic agent which regulates the radiative deactivation of the luminescent ZnS NPs component. After UV irradiation the photoactive polymer becomes purple in color. Therefore, these basic studies can lead to the development of innovative functional and nanostructured materials with photosensitive character as photosensitive molecular switches
- …