26 research outputs found

    On the coupling integrals arising in the method of moments formulation of laterally bounded structures

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    A generic integral equation and method of moments formulation is presented for laterally bounded stratified media including planar metallization. The main asset of the developed approach is its flexibility, as it encompasses generic lateral boundary conditions and explicitly applies to any linear subsectional basis functions with constant surface divergence. This includes the rooftop functions on rectangular and triangular supports currently proposed in standard method of moment meshers. This approach provides closed expressions for the coupling integrals appearing in the method of moments matrix elements. These formulas are based of Green's functions modal expansions and in the possibility, conclusively demonstrated in this paper to transform the surface integrals into contour integrals allowing an efficient and systematic implementation of the procedure. Full derivations are presented for several lateral boundary conditions, including rectangular and circular metallic cavities and periodic structures. Numerical examples including the analysis of real-life planar boxed circuits are presented. In all cases the obtained results compare favourably with other existing techniques

    Design review of a compact and low cost elementary radiating cell for satellite broadcasting automotive receiving arrays

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    This communication presents a review of the developments carried out towards the electromagnetic modeling, design and practical implementation of the basic building block of a planar antenna for the reception of Ku-band satellite broadcasting services from user terminals on board automotive platforms. The antenna is conceived as a low profile phased array with fully electronic beam steering and polarization tracking capabilities. This phased array is intended to address the market of low cost consumer applications, which imposes stringent structural and performance-to-price ratio requirements. As will be shown next, these demanding requirements are going to drive the design of the array basic building block: the so-called Elementary Radiating Cell (ERC)

    Sema3E/PlexinD1 regulates the migration of hem-derived Cajal-Retzius cells in developing cerebral cortex

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    International audienceDuring the development of the cerebral cortex, Cajal-Retzius (CR) cells settle in the preplate and coordinate the precise growth of the neocortex. Indeed, CR cells migrate tangentially from specific proliferative regions of the telencephalon (for example, the cortical hem (CH)) to populate the entire cortical surface. This is a very finely tuned process regulated by an emerging number of factors that has been sequentially revealed in recent years. However, the putative participation of one of the major families of axon guidance molecules in this process, the Semaphorins, was not explored. Here we show that Semaphorin-3E (Sema3E) is a natural negative regulator of the migration of PlexinD1-positive CR cells originating in the CH. Our results also indicate that Sema3E/PlexinD1 signalling controls the motogenic potential of CR cells in vitro and in vivo. Indeed, absence of Sema3E/PlexinD1 signalling increased the migratory properties of CR cells. This modulation implies negative effects on CXCL12/CXCR4 signalling and increased ADF/Cofilin activity

    Role of the Cellular Prion Protein in Oligodendrocyte Precursor Cell Proliferation and Differentiation in the Developing and Adult Mouse CNS

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    There are numerous studies describing the signaling mechanisms that mediate oligodendrocyte precursor cell (OPC) proliferation and differentiation, although the contribution of the cellular prion protein (PrPc) to this process remains unclear. PrPc is a glycosyl-phosphatidylinositol (GPI)-anchored glycoprotein involved in diverse cellular processes during the development and maturation of the mammalian central nervous system (CNS). Here we describe how PrPc influences oligodendrocyte proliferation in the developing and adult CNS. OPCs that lack PrPc proliferate more vigorously at the expense of a delay in differentiation, which correlates with changes in the expression of oligodendrocyte lineage markers. In addition, numerous NG2-positive cells were observed in cortical regions of adult PrPc knockout mice, although no significant changes in myelination can be seen, probably due to the death of surplus cells

    Socio-Demographic Health Determinants Are Associated with Poor Prognosis in Spanish Patients Hospitalized with COVID-19

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    Introduction Social vulnerability is a known determinant of health in respiratory diseases. Our aim was to identify whether there are socio-demographic factors among COVID-19 patients hospitalized in Spain and their potential impact on health outcomes during the hospitalization. Methods A multicentric retrospective case series study based on administrative databases that included all COVID-19 cases admitted in 19 Spanish hospitals from 1 March to 15 April 2020. Socio-demographic data were collected. Outcomes were critical care admission and in-hospital mortality. Results We included 10,110 COVID-19 patients admitted to 18 Spanish hospitals (median age 68 (IQR 54–80) years old; 44.5% female; 14.8% were not born in Spain). Among these, 779 (7.7%) cases were admitted to critical care units and 1678 (16.6%) patients died during the hospitalization. Age, male gender, being immigrant, and low hospital saturation were independently associated with being admitted to an intensive care unit. Age, male gender, being immigrant, percentile of average per capita income, and hospital experience were independently associated with in-hospital mortality. Conclusions Social determinants such as residence in low-income areas and being born in Latin American countries were associated with increased odds of being admitted to an intensive care unit and of in-hospital mortality. There was considerable variation in outcomes between different Spanish centers.JPA is under contract within the Ramón y Cajal Program (RYC-2016-20155, Ministerio de Economía, Industria y Competitividad, Spain). Investigators of Spanish Social-Environmental COVID-19 Register: Steering Committee: F. Javier Martín-Sánchez, Adrián Valls Carbó, Carmen Martínez Valero, Juan de D. Miranda, Juan Pedro Arrebola, Marta Esteban López, Annika Parviainen, Òscar Miró, Pere Llorens, Sònia Jiménez, Pascual Piñera, Guillermo Burillo, Alfonso Martín, Jorge García Lamberechts, Javier Jacob, Aitor Alquézar, Juan González del Castillo, Amanda López Picado and Iván Núñez. Participating centers: Oscar Miró y Sonia Jimenez. Hospital Clinic de Barcelona. José María Ferreras Amez. Hospital Clínico Universitario Lozano Blesa. Rafael Rubio Díaz. Complejo Hospitalario de Toledo. Julio Javier Gamazo del Rio. Hospital Universitario de Galdakao. Héctor Alonso. Hospital Universitario Miguel de Valdecilla. Pablo Herrero. Hospital Universitario Central de Asturias. Noemí Ruiz de Lobera. Hospital San Pedro de Logroño. Carlos Ibero. Complejo Hospitalario de Navarra. Plácido Mayan. Hospital Clínico Universitario de Santiago. Rosario Peinado. Complejo Hospitalario Universitario de Badajoz. Carmen Navarro Bustos. Hospital Universitario Virgen de la Macarena. Jesús Álvarez Manzanares. Hospital Universitario Rio Hortega. Francisco Román. Hospital Universitario General de Alicante. Pascual Piñera. Hospital Universitario Reina Sofia de Murcia. Guillermo Burillo. Hospital Universitario de Canarias de Tenerife. Javier Jacob. Hospital Universitario de Bellvitge. Carlos Bibiano. Hospital Universitario Infanta Leonor.Peer reviewe
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