Una formulación alternativa para el método de los elementos de contorno en elastodinámica: método de la matriz de masa equivalente

VII CONGRESO NACIONAL DE INGENIERÍA MECÁNICA EN VALENCIAEn esta comunicación se presenta una técnica para el análisis de problemas elastodinámicos bidimensionales basada en el Método de los Elementos de Contorno. Se plantea una formulación alternativa que da lugar al Método de la Matriz de Masa Equivalente, que representa una extensión dinámica de la formulación estática. La matriz de masa, que se obtiene a partir de la solución fundamental estática y de un conjunto de funciones especiales, modeliza el efecto de las fuerzas de inercia del cuerpo bajo estudio. Se obtiene así un sistema de ecuaciones diferenciales. cuya integración numérica proporciona la respuesta en el tiempo. La exactitud del método se comprueba con algunos ejemplos de aplicación.In this paper a procedure for the analysis of bidimensional elastodynamic problems is presented. The procedure is based on the Boundary Element Method. An alternative formulation which gives ríse to the Equivalent Mass MatriI Method is stated. This represents an extension of the static formulation to the dynamic field. The mass matríI, which is obtained from the static funda mental solution and f rom a set of special f unctions, accounts for the effect of inertial forces in the body under consideration. In this way, a differential equation system is obtained, the integration of which results in the time response. Some eiamples check for the method accuracy

Aer receptors influence the Pseudomonas chlororaphis PCL1606 lifestyle.

Pseudomonas chlororaphis PCL1606 (PcPCL1606) is a rhizobacterium isolated from avocado roots, which is a favorable niche for its development. This strain extensively interacts with plant roots and surrounding microbes and is considered a biocontrol rhizobacterium. Genome sequencing has shown the presence of thirty-one potential methyl-accepting chemotaxis proteins (MCPs). Among these MCPs, two candidates are putative functional aerotaxis receptors, encoded at locus PCL1606_41090 (aer1- 1) and locus PLC1606_20530 (aer1-2), that are homologous to the Aer receptor of Pseudomonas aeruginosa strain PaO1. Single- and double-deletion mutants in one or both genes have led to motility deficiencies in oxygen-rich areas, particularly reduced swimming motility compared with that of wildtype PcPCL1606. No differences in swarming tests were detected, and less adhesion by the aer double mutant was observed. However, the single and double mutants on avocado plant roots showed delayed biocontrol ability. During the first days of the biocontrol experiment, the aer-defective mutants also showed delayed root colonization. The current research characterizes the presence of aer transductors on P. chlororaphis. Thus, the functions of the PCL1606_41090 and PCL1606_20530 loci, corresponding to genes aer1-1 and aer1-2, respectively, are elucidated.This research was supported by the Spanish Plan Nacional ICDCI. Grant AGL2017-83368-C2-1-R and partially supported by the European Union (FEDER)

Multifed Printed Reflectarray With Three Simultaneous Shaped Beams for LMDS Central Station Antenna

A two-layer reflectarray is proposed as a central station antenna for a local multipoint distribution system (LMDS) in the 24.5-26.5 GHz band. The antenna produces three independent beams in an alternate linear polarization that are shaped both in azimuth (sectored) and in elevation (squared cosecant). The design process is divided into several stages. First, the positions of the three feeds are established as well as the antenna geometry to produce the three beams in the required directions. Second, the phase distribution on the reflectarray surface, which produces the required beam shaping, is synthesized. Third, the sizes of the printed stacked patches are adjusted so that the phase-shift introduced by them matches the synthesized phase distribution. Finally, the radiation patterns are computed for the central and lateral beams, showing a shaping close to the requirements. A breadboard has been manufactured and measured in an anechoic chamber, showing a good behavior, which validates the designing methodology

Reflectarray Pattern Optimization for Advanced Wireless Communications

A framework for the design and optimization of large dual-linear polarized, shaped-beam reflectarrays for advanced wireless communications is presented. The methodology is based on the generalized intersection approach (IA) algorithm for both phase-only synthesis (POS) and direct optimization of the reflectarray layout, as well as on the use of a method of moments in the spectral domain assuming local periodicity. A thorough description of the design and optimization procedures is provided. To demonstrate the capabilities of the proposed framework, two examples are considered. The first example is a shaped-beam reflectarray for future 5G base stations working in the millimeter waveband, radiating a sectored-beam pattern in azimuth and squared-cosecant pattern in elevation to provide constant power in the coverage area. The second example is a very large contoured-beam reflectarray for direct-to-home (DTH) broadcasting based on real mission requirements with Southern Asia coverage

Cuantificación del calcio mineral en la ateromatosis carotídea mediante angiografía por tomografía computarizada: perfil evolutivo y relación con la progresión del grado de estenosis volumétrica

Antecedentes: La cuantificación y caracterización del calcio (Ca) mineral (hidroxiapatita) en la bifurcación carotídea con AngioTC, y su relación con la sintomatología neurológica, en un estudio preliminar de casos y controles (Miralles y cols. Eur J Vasc Endovasc Surg 2006), constituye la base conceptual del presente estudio. Sus resultados, al igual que los de otras publicaciones, sugerían un posible papel protector del calcio en el desarrollo de eventos neurológicos. Sin embargo, su relación con la progresión de la ateromatosis carotídea ha sido escasamente analizado. Objetivos: Principales: 1. Diseñar un método de medición volumétrica de la ateromatosis (AE) carotídea y contenido de Ca mediante AngioTC. 2. Analizar el grado de calcificación arterial y su relación con la progresión de la ateromatosis carotídea. Secundarios: 3. Evaluar la relación entre calcificación arterial carotídea y descalcificación ósea, así como su posible conexión a través de los factores humorales implicados en la regulación del metabolismo Ca-P. 4. Estudiar un posible mecanismo genético común: relación entre los polimorfismos del gen de la OPG y la progresión de la calcificación en la placa de ateroma. Pacientes y método: Diseño: Cohortes, medidas repetidas. Pacientes: 54 pacientes, neurológicamente asintomáticos con estenosis de la arteria carótida interna (ECI) >50% (eco-Doppler). Determinaciones: Medición del grado de ECI mediante eco-Doppler y proyecciones MIP 2D de AngioTC. Medición del Volumen del molde de contraste y contenido de Ca (AngioTC cuantitativa: Agatston score modificado: volumen de Ca (mm3) x densidad radiológica (unidades Hounsfield, UH) en reconstrucción volumétrica (volume rendering) de la bifurcación carotídea (volumen de contraste entre 2 cm por debajo y 1 cm por encima de la bifurcación [VBif] y su cociente con un segmento de 1 cm en carótida primitiva [VCP]) (n=45). En todos los pacientes se repitió la exploración a los 122 meses para valorar la variación en el contenido de Ca y en el grado de estenosis volumétrica de la bifurcación, como medición indirecta de la progresión/regresión de la AE carotídea. Densitometría ósea de columna y fémur (n=32), (basal y a los 122 meses). Bioquímica y metabolismo Ca-P (Ca, P, vit D, PTH). Determinación de osteopontina (OPN) y osteoprotegerina (OPG) sérica y distribución de 7 SNPs del gen de la OPG seleccionados sobre bases bibiliométricas (n=48). Análisis estadístico: descriptivo (media [DE]); concordancia intra e interobservador (gráficos de Bland-Altman) y coeficiente de correlación intraclase (CCI), precisión eco-Doppler/AngioTC y Volumetría 3D/MIP 2D: sensibilidad (Sens), especificidad (Esp), índice kappa, curvas operador receptor (COR), comparación de medias (prueba T), análisis de regresión uni y multivariable. Resultados: 1. La medición volumétrica de la bifurcación carotídea mostró una concordancia intra e interobservador con un CCI de 0,96 (IC 95%: 0,904-0,985) y 0,94 (IC 95%: 0,822-0,977), respectivamente. El VBif/VCP del grupo de ECI50% (p=0,001). El punto de corte óptimo de la relación VBif/VCP se identificó a partir de la curva COR en 4,1 (Sens=0,75; Esp=0,75, kappa=0,46). 2. La medición mediante AngioTC demostró, a los 12 meses, un aumento del volumen promedio de pared arterial (disminución del volumen de la columna de contraste), respecto al valor basal (475,45 [155,6] mm3xUH vs 501,3 [171,9] mm3xUH, p=0,04), así como un aumento del Ca intraplaca (56,8 [52,3] vs 64,58 [57,8] mm3xUH, p=0,002). El análisis univariable demostró una correlación inversa entre el contenido basal de Ca y progresión de estenosis volumétrica de la bifurcación (r=-0,481; p<0,001). El análisis de regresión múltiple permitió ajustar un modelo de regresión lineal entre la reducción del volumen de la bifurcación (progresión de AE carotídea) y el contenido basal de Ca intraplaca, ajustado por el índice de masa corporal (IMC). 3. Se observó una disminución estadísticamente significativa de la densidad ósea respecto a la determinación basal (2,08 [0,22] vs 2,06 [0,23] g/cm2; p=0,013), así como un aumento del Ca intraplaca respecto a los valores basales (79,2 [55] vs 64,58 [49,2] mm3xUH, p=0,12). Sin embargo, se identificó una correlación positiva entre la variación relativa del contenido de Ca y la variación relativa de la densidad ósea (r=0,574, p=0,003). En otras palabras, una mayor tendencia a la osteoporosis se asoció con una menor tendencia a la progresión del calcio intraplaca. Así mismo, se observó una relación entre los niveles plasmáticos de Vit D y la densitometría basal (r=-0,459, p=0,036) y entre los niveles plasmáticos de HDL-colesterol y la variación relativa, respecto a los valores basales, de la densidad ósea (r=-0,579, p=0,009). El análisis univariable demostró una correlación inversa entre el incremento del contenido de calcio intraplaca y los niveles plasmáticos de vit D (r=0,4; p=0,025) y score Z en fémur (r=0,378; p=0,047). Sólo la concentración de P en orina presentó una correlación positiva moderada con el aumento de Ca intraplaca (r=0,488, p=0,015). Ninguna otra variable, entre los parámetros del metabolismo Ca-P, mostró relación con la calcificación arterial. 4. No se observaron diferencias entre la distribución de los SNPs en los pacientes de la muestra del estudio y el grupo control. Tampoco se observó relación entre el genotipo (SNPs) y la concentración de OPG sérica. Conclusiones: 1. La medición volumétrica de la bifurcación carotídea supone un nuevo concepto basado en la valoración de la carga de placa más que en su efecto hemodinámico o estenosis máxima. Dada su precisión en la detección de variaciones pequeñas de la luz arterial, este método puede ser de especial utilidad en estudios de progresión de placa. 2. Los resultados de este estudio sugieren que un mayor contenido de Ca confiere mayor estabilidad frente a la progresión de la AE carotídea y, eventualmente, a su capacidad para generar sintomatología tromboembólica. 3. Encontramos una tendencia independiente a la progresiva calcificación arterial y descalcificación ósea. Sin embargo, los resultados sugieren una relación temporal directa en la evolución del depósito de calcio en ambas localizaciones, por lo que no es posible descartar que su modulación se rija por mecanismos similares. 4. No se observó una relación estadísticamente significativa entre la distribución de los SNPs analizados y los niveles de la OPG o la calcificación intraplaca en los pacientes estudiados.Background: Quantification and characterization of mineral calcium (Ca) (hydroxyapatite) in the carotid bifurcation with AngioCT, and its relation with neurological symptomatology, in a preliminary case-control study (Miralles et al., Eur J Vasc Endovasc Surg 2006) Constitutes the conceptual basis of the present study. Their results, like those of other publications, suggested a possible protective role for calcium in the development of neurological events. However, its relationship with the progression of carotid atheromatosis has been scarcely analyzed. Objectives: Primary: 1. To design a method of volumetric measurement of carotid atheromatosis (AE) and Ca content by AngioCT. 2. To analyze the degree of arterial calcification and its relation with the progression of carotid atheromatosis. Secondary: 3. To evaluate the relationship between carotid artery calcification and bone decalcification, as well as its possible connection through humoral factors involved in the regulation of Ca-P metabolism. 4 To study a possible common genetic mechanism: relationship between polymorphisms of osteoprotegerin (OPG) gene and the progression of calcification in the atherosclerotic plaque. Patients and method: Design: Cohorts, repeated measures. Patients: 54 asymptomatic patients with internal carotid artery stenosis CAS>50% (duplex scanning). Determinations: Measurement of CAS grade with duplex scanning and MIP 2D projections of AngioCT. Volume measurement of contrast medium and Ca content (quantitative AngioCT: Agatston score: Ca volume (mm3) x radiological density (Hounsfield units, HU) in volume reconstruction of the carotid bifurcation [contrast volume between 2 cm below and 1 cm above the bifurcation (BifV) and its ratio with that from 1 cm segment in common carotid artery (CCV)] (n=45). In all patients, the scans was repeated at 12±2 months to assess the variation in Ca content and the degree of bifurcation volumetric stenosis as an indirect measure of carotid AE progression / regression. Bone and spine densitometry (n=32), where obtained at baseline and after 12±2 months, as well as Biochemistry and Ca-P metabolism parameters (Ca, P, vit D, PTH). Determination of plasma levels of osteopontin (OPN) and osteoprotegerin (OPG) where compared with the distribution of 7 SNPs of the OPG gene selected on bibiliometrics bases (n=48). Statistical analysis: descriptive [mean (SD)]; Intra and interobserver agreement (Bland-Altman plots and intraclass correlation coefficient (ICC), duplex scanning / AngioCT precision and 3D Volumetry / MIP 2D: Sensitivity (S), specificity (E), kappa index, ROC curves, means comparison (T test), univariate and multivariate regression analysis. Results: 1.The volumetric measurement of the carotid bifurcation showed intra and interobserver agreement with a ICC of 0.96 (95% CI: 0.904-0.985) and 0.94 (95% CI: 0.822-0.977), respectively. The BifV/CCV of the CAS > 50% group was 5.2±1.8 vs 3.8 ±1.3 in the CAS >50% group (p=0.001). The optimum cutoff point for the BifV/CCV relation was identified from the ROC curve at 4,1 (S=0.75, E=0.75, kappa=0.46). 2. AngioCT measurement showed, at 12 months, an increase in mean arterial wall volume (decrease in contrast column volume), compared to baseline (475.45 [155.6] mm3xHU vs 501.3 [171.9] mm3xHU, p=0.04), as well as an increase in intraplaque Ca (56.8 [52.3] vs 64.58 [57.8] mm3xHU, p=0.002). Univariate analysis showed an inverse correlation between basal Ca content and progression of bifurcation volumetric stenosis (r=-0.481; p<0.001). The multiple regression analysis allowed to fit a linear regression model between the reduction of bifurcation volume (carotid AE progression) and the baseline intraplaque content of Ca, adjusted for body mass index (BMI). 3. A statistically significant decrease in bone density was observed with respect to the baseline determination (2.08 [0.22] vs 2.06 [0.23] g/cm2, p=0.013), as well as increased intraplaque Ca as compared with baseline values (79.2 [55] vs 64.58 [49.2] mm3xHU, p=0.12). However, a positive correlation was identified between the relative variation of Ca content and the relative variation of bone density (r=0.574, p=0.003). In other words, a greater tendency to osteoporosis was associated with a lower tendency to progression of intraplaque calcium. Likewise, a relationship between Vit D plasma levels and baseline densitometry (r=-0.459, p=0.036) and between plasma HDL-cholesterol levels and the relative variation, relative to baseline values, were observed. Bone density (r=-0.579, p=0.009). The univariate analysis showed an inverse correlation between the basal Ca content and the progression of bifurcation volumetric stenosis (r=-0.481; p<0.001), as well as between the increase in the intra-plaque calcium content and plasma levels of vit D (R=0.4, p=0.025) and femur Z score (r=0.378, p=0.047). Only the urine P concentration presented a moderate positive correlation with the increase of intra-plaque Ca (r=0.488, p=0.015). No other variable, among Ca-P metabolism parameters, was related to arterial calcification. 4. There were no differences between the distribution of SNPs in patients and control group. There was also no relationship between genotype and serum OPG concentration. Conclusions: 1. The volumetric measurement of the carotid bifurcation is a new concept based on the assessment of the plaque load rather than on its hemodynamic effect or maximal stenosis. Given its accuracy in detecting small variations in arterial lumen, this method may be especially useful in plaque progression studies. 2. The results of this study suggest that a higher content of Ca confers greater stability against the progression of carotid AE and, eventually, its capacity to generate symptomatology. 3. We found an independent tendency to progressive arterial calcification and bone decalcification. However, the results suggest a direct temporal relationship in the evolution of the calcium deposit in both locations, so it is not possible to rule out that its modulation is controlled by similar mechanisms. 4. The results are inconclusive with regard to the role of OPG in AE plaque calcification. No significant relationship between the distribution of SNPs analyzed and OPG levels in the studied patients was observed

Analysis of dual-reflector antennas with a reflectarray as subreflector

In this paper, a modular technique is described for the analysis of dual-reflector antennas using a reflectarray as a subreflector. An antenna configuration based on a sub-reflectarray and a parabolic main reflector provides better bandwidth than a single reflectarray, and has a number of advantages compared with a conventional dual-reflector antenna. Examples include the possibility of beam shaping by adjusting the phase on the sub-reflectarray, and potential capabilities to scan or reconfigure the beam. The modular technique implemented for the antenna analysis combines different methods for the analysis of each part of the antenna. First, the real field generated by the horn is considered as the incident field on each reflectarray element. Second, the reflectarray is analyzed with the same technique as for a single reflectarray, i.e., considering local periodicity and the real angle of incidence of the wave coming from the feed for each periodic cell. Third, the main reflector is analyzed using the Physical Optics (PO) technique, where the current on the reflector surface is calculated by summing the radiation from all the reflectarray elements. Finally, the field is calculated on a rectangular periodic mesh at a projected aperture, and then a time-efficient fast Fourier transform (FFT) algorithm is used to compute the radiation pattern of the antenna. The last step significantly improves the computational efficiency. However, it introduces a phase error, which reduces the accuracy of the radiation patterns for radiation angles far away from the antenna's axis. The phase errors have been evaluated for two integration apertures. It has been demonstrated that accurate patterns are obtained in an angular range of plusmn6deg, which is sufficient for large reflectors. The method of analysis has been validated by comparing the results with simulations obtained from GRASP8. Finally, the theoretical beam-scanning performance of the antenna is analyzed

Pilotaje de un protocolo normalizado de trabajo de dispensación para farmacia comunitaria

INTRODUCCIÓN Dentro de las actividades que el farmacéutico realiza en la farmacia, la dispensación es el servicio más demandado y reconocido socialmente por el ciudadano que acude a la farmacia, además se trata de la labor que más tiempo ocupa en la rutina diaria del profesional farmacéutico. El primer objetivo de la dispensación es garantizar el acceso al medicamento. Sin embargo, la alta prevalencia de fallos en la farmacoterapia constituye un problema de salud pública y hace necesario que la actuación profesional del farmacéutico sea más comprometida y activa. El Documento de Consenso sobre Atención Farmacéutica del Ministerio de Sanidad y Consumo invita a cada oficina de farmacia a disponer de protocolos normalizados de trabajo para la dispensación. Cada farmacia debe disponer de protocolos normalizados de trabajo que permitan un flujo de comunicación entre el farmacéutico y el paciente, con el fin de obtener la información necesaria para poder tomar decisiones de forma ágil garantizando el uso correcto de los medicamentos y disminuyendo así la aparición de resultados negativos de los medicamentos.OBJETIVO Pilotar un protocolo normalizado de trabajo para el servicio de dispensación en farmacia comunitaria.MÉTODO Estudio descriptivo transversal. El ámbito de estudio se realizará en farmacias comunitarias de España contactadas a través del CAF-STADA y SEFAC en las que trabajan farmacéuticos comunitarios

Demonstration of a Shaped Beam Reflectarray Using Aperture-Coupled Delay Lines for LMDS Central Station Antenna

A shaped-beam reflectarray based on patches, aperture-coupled to delay lines is demonstrated for local multipoint distribution system (LMDS) central station antennas, in the 10.10-10.70 GHz band. The antenna must cover a 60deg-sector in azimuth with a squared cosecant pattern in elevation. The design process consists of two steps. First, a phase-only pattern synthesis technique is applied to obtain the required phase-shift distribution on the reflectarray surface which generates the shaped pattern. The second stage consists of determining the length of the delay lines, aperture-coupled to the square patches, in order to achieve the phase distribution synthesized in the previous step. Two reflectarray antennas have been designed, one for vertical (V) and the other for horizontal (H) polarization. A breadboard for V-polarization has been manufactured and tested in an anechoic chamber, showing a good agreement between theoretical and measured radiation patterns