COMPARACIÓN IN VITRO DEL EFECTO PROCINÉTICO DE ERITROMICINA, AZITROMICINA Y CLARITROMICINA EN DUODENO DE Oryctolagus cuniculus

Desde la introducción de la Eritromicina a la práctica por sus propiedades antibacterianas, ha presentado reacciones adversas gastrointestinales. Subsecuentes estudios han demostrado que la estructura de los macrólidos les confiere una acción procinética a estas drogas, como agonistas de la motilina o como estimulante de las vías colinérgicas. El objetivo de nuestro estudio fue comparar el efecto de Eritromicina, Azitromicina y Claritromicina sobre la motilidad intestinal utilizando un modelo experimental de duodeno aislado de Oryctolagus cuniculus, el cual se dividió en 3 segmentos y  administrándosele por cada segmento los compuestos mencionados a concentraciones distintas de cada macrólido. Se determinó la frecuencia y la amplitud de las contracciones del duodeno aislado antes y después de la administración de Eritromicina, Azitromicina y Claritromicina en cada segmento. Los tres macrólidos estudiados aumentan la amplitud de las contracciones pero no sucede lo mismo con la frecuencia la cual se mantiene manera constante. Se establece que la Eritromicina, Azitromicina y Claritromicina tiene efectos importantes sobre la motilidad del duodeno de Oryctolagus cuniculus, llegando a presentar un mayor efecto la eritromicina. Palabras Claves: Motilidad, Oryctolagus cuniculus, Eritromicina, Azitromicina, Claritromicina.<w:LsdException Locked="false" Priority="66" SemiHidden="false" UnhideWhenUsed="false" Name="

Contaminación de agua superficial de la periferia urbana de Puerto Maldonado, al sureste de la amazonia peruana

The aim of this study was to evaluate the contamination of surface waters in the urban periphery of Puerto Maldonado (Peruvian Amazon), using biological, physicochemical, and microbiological analyses. The water samples were collected in six water bodies (two rivers, three streams and one lake). The physicochemical parameters of each study site did not exceed the limits of the Peruvian Environmental Quality Standard (ECA), except for dissolved oxygen in rivers near urban areas. Pollution of water resources is related to raw sewage and rainwater runoff. Thus, the highest points of faecal contamination were in rivers near urban areas, exceeding the threshold established by the ECA for the conservation of the aquatic environment (CFU ml-1 >2000). In the Madre de Dios River, the concentration of faecal coliforms exceeded the maximum allowed by the ECA by 75 fold, indicating that the Tambopata and Madre de Dios rivers of Puerto Maldonado are heavily contaminated.El objetivo del estudio fue evaluar la contaminación de aguas superficiales en la periferia urbana de Puerto Maldonado (amazonia peruana), utilizando análisis biológicos, fisicoquímicos y microbiológicos. Las muestras de agua se colectaron en seis cuerpos de agua (dos ríos, tres quebradas y un lago). Los parámetros fisicoquímicos de cada sitio de estudio no superaron los límites del Estándar de Calidad Ambiental peruano (ECA), excepto el oxígeno disuelto en ríos cercanos a zonas urbanas. La contaminación de los recursos hídricos está relacionada con los vertidos de aguas residuales y la escorrentía de aguas pluviales. Así, los mayores puntos de contaminación fecal fueron en los ríos cercanos a las zonas urbanas, superando el límite establecido por el ECA para la conservación del medio acuático (UFC ml-1 >2000). En el río Madre de Dios, la concentración de coliformes fecales superó en 75 veces al máximo permitido por el ECA, indicando que los ríos Tambopata y Madre de Dios de Puerto Maldonado están fuertemente contaminados

Effect of aliskiren on post-discharge outcomes among diabetic and non-diabetic patients hospitalized for heart failure: insights from the ASTRONAUT trial

Aims The objective of the Aliskiren Trial on Acute Heart Failure Outcomes (ASTRONAUT) was to determine whether aliskiren, a direct renin inhibitor, would improve post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction. Pre-specified subgroup analyses suggested potential heterogeneity in post-discharge outcomes with aliskiren in patients with and without baseline diabetes mellitus (DM). Methods and results ASTRONAUT included 953 patients without DM (aliskiren 489; placebo 464) and 662 patients with DM (aliskiren 319; placebo 343) (as reported by study investigators). Study endpoints included the first occurrence of cardiovascular death or HHF within 6 and 12 months, all-cause death within 6 and 12 months, and change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 1, 6, and 12 months. Data regarding risk of hyperkalaemia, renal impairment, and hypotension, and changes in additional serum biomarkers were collected. The effect of aliskiren on cardiovascular death or HHF within 6 months (primary endpoint) did not significantly differ by baseline DM status (P = 0.08 for interaction), but reached statistical significance at 12 months (non-DM: HR: 0.80, 95% CI: 0.64-0.99; DM: HR: 1.16, 95% CI: 0.91-1.47; P = 0.03 for interaction). Risk of 12-month all-cause death with aliskiren significantly differed by the presence of baseline DM (non-DM: HR: 0.69, 95% CI: 0.50-0.94; DM: HR: 1.64, 95% CI: 1.15-2.33; P < 0.01 for interaction). Among non-diabetics, aliskiren significantly reduced NT-proBNP through 6 months and plasma troponin I and aldosterone through 12 months, as compared to placebo. Among diabetic patients, aliskiren reduced plasma troponin I and aldosterone relative to placebo through 1 month only. There was a trend towards differing risk of post-baseline potassium ≥6 mmol/L with aliskiren by underlying DM status (non-DM: HR: 1.17, 95% CI: 0.71-1.93; DM: HR: 2.39, 95% CI: 1.30-4.42; P = 0.07 for interaction). Conclusion This pre-specified subgroup analysis from the ASTRONAUT trial generates the hypothesis that the addition of aliskiren to standard HHF therapy in non-diabetic patients is generally well-tolerated and improves post-discharge outcomes and biomarker profiles. In contrast, diabetic patients receiving aliskiren appear to have worse post-discharge outcomes. Future prospective investigations are needed to confirm potential benefits of renin inhibition in a large cohort of HHF patients without D

Sur une formulation variationnelle à deux champs en élasticité couplée à l’endommagement. (A two-field variational formulation in elasticity coupled to damage)

International audienc

A two-field finite element formulation for elasticity coupled to damage

International audienc

Calibracion del Portal de Porticos en Base a Ensayos PsD Realizados en el Laboratorio ELSA Sobre un Edificio de 4 Pisos

El Portal de Pórticos es un programa de cálculo por elementos finitos de una nueva clase: se trata de un Portal de Cálculo. Los Portales de Cálculo se caracterizan porque el usuario final no tiene acceso a ellos directamente sino a través de la Web. El Portal de Pórticos (Portal of Damage en Inglés), permite el análisis de estructuras aporticadas sometidas a solicitaciones extraordinarias. Se trata de un programa no lineal, dinámico y basado en la teoría del daño concentrado. Esta última puede ser definida como la Mecánica de la Fractura para estructuras aporticadas al combinar sus métodos con el concepto de rótula plástica y la Teoría de Estructuras. También, se describe una prueba experimental de un edificio de concreto armado de cuatro pisos, llevada a cabo en el European Laboratory for Structural Assessment (ELSA), sometido a un acelerograma artificial derivado del sismo de Friuli de 1976 mediante el método pseudodinámico (PsD). Finalmente, se describe la simulación numérica de este ensayo y posteriormente se comparan los resultados experimentales con los resultados de la simulación y de esta manera calibrar el programa Portál de Pórticos.JRC.G.5-European laboratory for structural assessmen

A new comprehensive model of damage for flexural subassemblies prone to fatigue

Fatigue resistance is a key performance for the life-cycle sustainability of materials and structures. Structural members subjected to flexural forces such as spring hinges in origami structures are one of the most commonly existing in nature and engineering practice but predicting their fatigue resistance is a challenge because of complex mechanisms of crack localization, nonstationary amplitudes in the time domain, and the influence of stress gradient due to bending moment. We developed a general lumped damage simulation model for predicting the fatigue life and the associated crack propagation in the full range of elastic and plastic amplitudes. It is found that the developed comprehensive damage model demonstrates a new perspective for fatigue-induced remaining life quantification for engineering structures. (c) 2021 Elsevier Ltd. All rights reserved

Damage Evolution Modeling for Steel Structures Subjected to Combined High Cycle Fatigue and High-Intensity Dynamic Loadings

This paper presents a method for modeling the initiation and propagation of the damage in steel structures under combined fatigue loading. An existing model in the literature is used as the main key to the development of the new formulation herein proposed, where a significant computational improvement for the cracking incubation phase under high cycle fatigue (HCF) is achieved. The results show a satisfactory comparison with experimental data available in the literature and the carried parametric simulations demonstrate the effectiveness of the model once strength reduction could be estimated after 0, 20, 40, and 60 years of HCF. The reduction of the structural capacity was evaluated by the consideration of the final damage due to a high-intensity dynamic loading at the end of the HCF phase

Parametric study of dynamic behaviour of RC dual system design with the Brazilian Standard Code using the lumped damage model

Analysis of RC structures subjected to seismic loads vary greatly around the world, from simplified static models to more advanced methods, which take account of real dynamic loads and the nonlinear response of structures. As a recent theory, lumped damage mechanics apply the concepts of damage mechanics and the classic fracture in plastic hinges for nonlinear analysis of RC structures. Therefore, this research analysed the behaviour of RC dual system structures designed according to Brazilian Standards Codes, that did not consider the recommendations of NBR 15421, under seven real seismic loads, with magnitude units in Richter scale (ML). It was concluded that all structures regardless of structural system and number of storeys might suffer severe values of structural damage when subjected to earthquake magnitudes equal or greater than 5.0 ML. Besides that, even for earthquake magnitudes above 3.0 ML, in most of structures, the interstorey drift ratio was not in requirements with international standard codes, causing cracking in nonstructural elements and demanding higher repair costs

Modeling of localization using Nash variational formulations: The extended damage mechanics

It is assumed in this paper that energy dissipation is a two-phase phenomenon. During the prelocalization stage, dissipation is a continuous process. After localization, it is lumped in surfaces of zero volume. To describe this process, it is proposed a new formulation called extended damage mechanics. The new framework incorporates the additional terms of lumped energy dissipation into a weak form of the damage evolution law. The variational formulation allowing for this approach characterizes the solution as a non-cooperative equilibrium point. This concept is also named after its inventor, the mathematician John Forbes Nash, as Nash point. Finally, numerical implementation of the extended damage mechanics is performed to describe the objectivity of the numerical simulations with respect to the finite element meshes in some practical cases of solids and structures