Comportamiento estructural de una vivienda con placas de concreto polimérico y otra de albañilería confinada, Villa El Salvador - 2019

El proyecto de investigación tiene la finalidad de realizar un análisis comparativo de los comportamientos estructurales de una vivienda de concreto polimérico y otra de albañilería confiando, en la metodología para el proyecto de investigación se trabajó de modo cuantitativa; con un tipo de investigación aplicada y un diseño experimental en el modo cuasi experimental, ya que se va realizar una manipulación de las variables de la investigación, con el objetivo de análisis el comportamiento estructural de una vivienda con placas de concreto polimérico y otra de albañilería confinada, por lo cual se determinó las siguientes resultados utilizando el método racional y los softwares de Excel y SAP2000, por lo tanto se pudo determinas que el concreto polimérico obtuvo una resistencia a la compresión de 388kg/cm2 y una resistencia a la flexión de 209.26 kg/cm2 por lo cual fue superior que el concreto convencional que se utilizar en la vivienda de albañilería confinada, por el otro lado para el tipo de suelo se obtuvo una capacidad portante de 1kg/cm2, y con un tipo de suelo arenoso de gran potencia, y por último se obtuvo los resultados del criterio del dimensionamiento, que nos indicó una cortante basal máxima de 34.09 toneladas en la vivienda de concreto polimérico y para la vivienda de albañilería confinada se determinó una cortante basal máxima de 58.808 toneladas, y para los desplazamiento de una vivienda de concreto polimérico obtuvo como resultados un desplazamiento máximo en el eje X y Y: -0.283 mm y 0.0842 mm y para la vivienda de albañilería confinada se obtuvo una desplazamiento máximo en el eje X y Y de -0.709 mm y -0.2633 mm, y por lo cual se concluyó que el comportamiento estructural de una vivienda con placas de concreto es más viable que uno de albañilería confinada

Ordering of Ge quantum dots on silicon surfaces via bottom-up and top-down approaches

The nanoscale ordering of inorganic semiconductor quantum dots (QDs) is crucial to obtain reliable structures for novel nanotechnological applications such as nanomemories, nanolasers and nanoelectronic devices. We have directly grown Ge QDs by physical vapour deposition (PVD) on Si(111), Si(100) and some of its vicinal surfaces and studied innovative bottom up techniques to order such nanostructures. Specifically, we harnessed naturally occurring instabilities due to reconstruction and intrinsic anisotropic diffusion in Si bare surfaces, such as step bunching and natural steps occurring in silicon vicinal surfaces, to order the QDs both in one dimension and in the plane. We have also shown the use of controlled quantities of surfactants, like Sb, dramatically improves the desired ordering. Moreover, we have assisted these self-assembling processes using top-down approaches like Focused Ion Beam (FIB) milling and STM nanoindentation to control the nucleation sites and the density of the Ge QDs. Real-time study of growth and self-assembly has been accomplished using Scanning Tunneling Microscopy imaging in UHV. An explanation of the occurring processes is given, and a software routine is used to quantify the ordering of the QDs both in pre-patterned and bare surfaces. Applications, mainly in the field of Nanocrystal Nonvolatile Memories, are discussed

Molecular Mechanisms Mediating Antiangiogenic Action of the Urokinase Receptor-Derived Peptide UPARANT in Human Retinal Endothelial Cells

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Chemical gradients in automotive Cu-SSZ-13 catalysts for NOx_{x} removal revealed by operando X-ray spectrotomography

NOx emissions are a major source of pollution, demanding ever improving performance from catalytic aftertreatment systems. However, catalyst development is often hindered by limited understanding of the catalyst at work, exacerbated by widespread use of model rather than technical catalysts, and global rather than spatially-resolved characterisation tools. Here we combine operando X-ray absorption spectroscopy with microtomography to perform 3D chemical imaging of the chemical state of copper species in a Cu-SSZ-13 washcoated monolith catalyst during NO$_{x}$ reduction. Gradients in copper oxidation state and coordination environment, resulting from an interplay of NOx reduction with adsorption-desorption of NH$_{3}$ and mass transport phenomena, were revealed with micrometre spatial resolution while simultaneously determining catalytic performance. Crucially, direct 3D visualisation of complex reactions on nonmodel catalysts is only feasible using operando X-ray spectrotomography, which can improve our understanding of structure-activity relationships including the observation of mass and heat transport effects

Serum fetuin-A and recurrent urolithiasis in young adults

Objective: Recurrence of urolithiasis is frequent. There are no reliable markers able to indicate recurrent stone former patients. Fetuin-A inhibits hydroxyapatite crystals formation and expansion. This study aims at evaluating whether serum fetuin-A may predict recurrent urolithiasis in young adults. Materials and methods: This is a multicentre study. Young adults patients with recurrent urolithiasis attending 3 urology clinics were enrolled from July 2011 to December 2012. Inclusion criteria were: age 18-40 years, presence of more than one kidney stone. Exclusion criteria were: diabetes mellitus, metabolic disorders, obesity, hypertension, cardiovascular disease, infection diseases. Controls were participants without history of urolithiasis and currently undetected stones. Routine biochemistry, serum concentration of oxalate, fetuin-A, and parathyroid hormone (PTH) were assessed; 24/h urinary excretion of creatinine, uric acid, calcium, sodium, phosphorus, potassium, magnesium, glucose, oxalate, amylase, and protein was measured. Kidney ultrasonography and plain X-ray examination was performed. Results: The total cohort was represented by 120 young adults participants (90 patients, and 30 controls). Clinical characteristics were not different between patients and controls. No significant differences were found in serum concentrations as well as in 24/h urinary excretion of recorded variables. No significant difference was found in serum concentration of fetuin-A (median 35.1 ± 18.62 SD Vs 35.12 ± 14.12, μg/ml; p = 0,908). Conclusions: The data of present study do not substantiate the hypothesis that serum fetuin-A may be a reliable predictor of recurrent urolithiasis in young adults

Dynamic measurements of pressures, sail shape and forces on a full-scale spinnaker

This work presents a full-scale experimental study on a sailing yacht in downwind conditions with simultaneous time-resolved measurements of pressures, sail shape and loads. Those on-water experiments on a J/80 class yacht permit the dynamic behaviour of the fluid structure system made of a light cloth sail and highly curved flow to be investigated. Aerodynamic forces on the asymmetric spinnaker were determined from pressure distribution and shape measurements and also from strain gauges located on the corners of the sail. Both time-averaged and instantaneous data are analysed. The time-averaged pressures and forces were studied according to the apparent wind angle. The pressure distribution and thus the loads tend to decrease when the apparent wind angle is increased. The standard deviation of pressures was largest near the luff, decreasing downstream. Simultaneous time series recordings of the pressure distributions, flapping sail shapes, and forces in the sheets show a strong correlation. Flapping of spinnaker creates pressure peaks at the leading edge, increasing the aerodynamic forces dynamically by 50 to 70%. These results will also give reliable benchmark data to validate unsteady fluid structure interaction predictions from numerical simulations of downwind sails

Endothelial PlexinD1 signaling instructs spinal cord vascularization and motor neuron development

How the vascular and neural compartment cooperate to achieve such a complex and highly specialized structure as the central nervous system is still unclear. Here, we reveal a crosstalk between motor neurons (MNs) and endothelial cells (ECs), necessary for the coordinated development of MNs. By analyzing cell-to-cell interaction profiles of the mouse developing spinal cord, we uncovered semaphorin 3C (Sema3C) and PlexinD1 as a communication axis between MNs and ECs. Using cell-specific knockout mice and in vitro assays, we demonstrate that removal of Sema3C in MNs, or its receptor PlexinD1 in ECs, results in premature and aberrant vascularization of MN columns. Those vascular defects impair MN axon exit from the spinal cord. Impaired PlexinD1 signaling in ECs also causes MN maturation defects at later stages. This study highlights the importance of a timely and spatially controlled communication between MNs and ECs for proper spinal cord development

Motor innervation directs the correct development of the mouse sympathetic nervous system

The sympathetic nervous system controls bodily functions including vascular tone, cardiac rhythm, and the “fight-or-flight response”. Sympathetic chain ganglia develop in parallel with preganglionic motor nerves extending from the neural tube, raising the question of whether axon targeting contributes to sympathetic chain formation. Using nerve-selective genetic ablations and lineage tracing in mouse, we reveal that motor nerve-associated Schwann cell precursors (SCPs) contribute sympathetic neurons and satellite glia after the initial seeding of sympathetic ganglia by neural crest. Motor nerve ablation causes mispositioning of SCP-derived sympathoblasts as well as sympathetic chain hypoplasia and fragmentation. Sympathetic neurons in motor-ablated embryos project precociously and abnormally towards dorsal root ganglia, eventually resulting in fusion of sympathetic and sensory ganglia. Cell interaction analysis identifies semaphorins as potential motor nerve-derived signaling molecules regulating sympathoblast positioning and outgrowth. Overall, central innervation functions both as infrastructure and regulatory niche to ensure the integrity of peripheral ganglia morphogenesis

An isoform of the giant protein titin is a master regulator of human T lymphocyte trafficking

Response to multiple microenvironmental cues and resilience to mechanical stress are essential features of trafficking leukocytes. Here, we describe unexpected role of titin (TTN), the largest protein encoded by the human genome, in the regulation of mechanisms of lymphocyte trafficking. Human T and B lymphocytes express five TTN isoforms, exhibiting cell-specific expression, distinct localization to plasma membrane microdomains, and different distribution to cytosolic versus nuclear compartments. In T lymphocytes, the LTTN1 isoform governs the morphogenesis of plasma membrane microvilli independently of ERM protein phosphorylation status, thus allowing selectin-mediated capturing and rolling adhesions. Likewise, LTTN1 controls chemokine-triggered integrin activation. Accordingly, LTTN1 mediates rho and rap small GTPases activation, but not actin polymerization. In contrast, chemotaxis is facilitated by LTTN1 degradation. Finally, LTTN1 controls resilience to passive cell deformation and ensures T lymphocyte survival in the blood stream. LTTN1 is, thus, a critical and versatile housekeeping regulator of T lymphocyte trafficking

An unusual case of bacillary angiomatosis in the oral cavity of an AIDS patient who had no concomitant tegumentary lesions – case report and review

Bacillary angiomatosis (BA) is an angioproliferative disease of immunocompromised patients that usually presents as vascular tumors in the skin and subcutaneous tissues. It is caused by chronic infections with either Bartonella henselae or B. quintana. Oral cavity BA is exceedingly rare and even rarer without simultaneous cutaneous disease. We report herein the case of a 51-year-old HIV-infected man who presented severe odynophagia and an eroded lesion on the hard palate that progressed to an oronasal fistula. No cutaneous lesions were recorded. Doxycycline led to complete resolution. To the best of our knowledge, only six previous cases of oral BA without tegumentary disease have been previously reported and none of them progressed to fistula