8 research outputs found

    El viaducto de San Giuliano, en Italia

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    This viaduct is part of the Sun Roadway, along the western coast of Italy. It is a reinforced concrete structure, with prestressed girders. It runs over a deep ravine, through which water flows intermittently into the Tiber river, a little below the bridge. As the hillside is not highly stable, the possibility of building a large arch was excluded, since the thrusts at the springers would be large. The total length to be bridged, 376 m, has been divided into three approach spans, each 32 m long, on one side, a further five spans, of similar length, on the other side, and a central 100 m long span. The remaining 20 m are taken up with the width of the piles. The project consists of two independent, twin bridges, since there is a separate structure for each of the two traffic directions. The width of each runway is 7.50 m. The planform of the bridge is S shaped, with a central straight section of 106 m length, and a maximum height of 74 m. The piles, of great height, are hollow columns, of rectangular cross section, and concreted by means of sliding formwork. The central span is the most Important feature of the project. It constitutes a portal fram .together with the two supporting piles. These slope towards the centre of the span. The intrados is arched shaped, and the extrados is the deck itself. The attachment of this central span with the springers is through hinged joints, consisting of reinforced neoprene plates. The straight sections of the bridge, of 32 m length, have been spanned with prestressed, prefabricated beams.Este viaducto, en la Autopista del Sol (Italia), es de hormigón armado con vigas pretensadas. Salva una vaguada profunda de aguas intermitentes que se unen al río Tíber en las proximidades del puente. Como las laderas de apoyo tienen poca consistencia se excluyó la solución de un arco de gran luz, dada la importancia del empuje en estos casos. Su longitud total es de 376 m, divididos en tres tramos de acceso de 33 m de luz cada uno, por un lado, y otros cinco tramos, también rectos y de la misma luz, para el otro acceso, y un tramo central de 100 metros. Los 20 m restantes corresponden a espesores de pilas. El complejo se compone de dos obras gemelas independientes, una para cada calzada de dirección única. El tablero tiene una anchura total de 24 m, y la de cada calzada es de 7,5 m. Al eje de la estructura se le ha dado forma de S en planta, con un trozo recto central de 106 m. La altura máxima es de 74 metros. Los soportes, de gran altura, están constituidos por dos montantes huecos, de sección rectangular, hormigonados con encofrados deslizantes. El tramo central, que es la parte más importante de la obra, consta de un pórtico de montantes inclinados y cabezal formando arco en su intradós y tablero en el extradós. La unión de dicho tramo central con los estribos se verifica por medio de articulaciones a base de placas de neopreno armado. Los tramos rectos del tablero, de 32 m de luz, se han salvado con vigas prefabricadas de hormigón pretensado

    Leptin induction following irradiation is a conserved feature in mammalian epithelial cells and tissues

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    PURPOSE: Leptin (LEP) is a peptide hormone with multiple physiological functions. Besides its systemic actions, it has important peripheral roles such as a mitogen action on keratinocytes following skin lesions. We previously showed that LEP mRNA is significantly induced in response to neutron irradiation in mouse skin and that the protein increases in the irradiated epidermis and in the related subcutaneous adipose tissue. In this work, we investigated the post-transcriptional regulation of LEP by miRNAs and the conservation of LEP's role in radiation response in human cells. METHODS: We used microarray analysis and real-time polymerase chain reaction (RT-PCR) to analyze modulation of miRNAs potentially targeting LEP in mouse skin following irradiation and bioinformatic analysis of transcriptome of irradiated human cell lines and cancer tissues from radiotherapy-treated patients to evaluate LEP expression. RESULTS AND CONCLUSIONS: We show that a network of miRNAs potentially targeting LEP mRNA is modulated in irradiated mouse skin and that LEP itself is significantly modulated by irradiation in human epithelial cell lines and in breast cancer tissues from radiotherapy-treated patients. These results confirm and extend the previous evidence that LEP has a general and important role in the response of mammalian cells to irradiation

    Proximity Array Device: A Novel Photon Detector Working in Long Wavelengths

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    We present here an innovative photon detector based on the proximity junction array device (PAD) working at long wavelengths. We show that the vortex dynamics in PAD undergoes a transition from a Mott insulator to a vortex metal state by application of an external magnetic field. The PAD also evidences a Josephson I-V characteristic with the external field dependent tunneling current. At high applied currents, we observe a dissipative regime in which the vortex dynamics is dominated by the quasi-particle contribution from the normal metal. The PAD has a relatively high photo-response even at frequencies below the expected characteristic frequency while, its superconducting properties such as the order parameter and the Josephson characteristic frequency can be modulated via external fields to widen the detection band. This device represents a promising and reliable candidate for new high-sensitivity long-wavelength detectors

    X-ray and neutron imaging for cultural heritage: the INFN-CHNet experience

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    This paper reports on the instrumentation and expertise developed within the INFN-CHNet network for X-ray and neutron imaging, which enable non-invasive identification of materials and production processes in the field of cultural heritage. INFN-CHNet is the network of the Italian National Institute of Nuclear Physics specifically dedicated to the development and application of scientific methods and technologies to cultural heritage. This article focuses on portable MA-XRF scanners, often complemented by additional techniques, PIXE imaging on a newly developed portable accelerator, X-ray radiography and tomography, exploited to their full potential also through the use of portable systems, and neutron radiography and tomography, which require large-scale facilities. In many respects, the information obtained from X-ray and neutron-based methods is complementary, facilitating a comprehensive characterisation of materials, structures, and manufacturing techniques

    X-ray and neutron imaging for cultural heritage: the INFN-CHNet experience

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    This paper reports on the instrumentation and expertise developed within the INFN-CHNet network for X-ray and neutron imaging, which enable non-invasive identification of materials and production processes in the field of cultural heritage. INFN-CHNet is the network of the Italian National Institute of Nuclear Physics specifically dedicated to the development and application of scientific methods and technologies to cultural heritage. This article focuses on portable MA-XRF scanners, often complemented by additional techniques, PIXE imaging on a newly developed portable accelerator, X-ray radiography and tomography, exploited to their full potential also through the use of portable systems, and neutron radiography and tomography, which require large-scale facilities. In many respects, the information obtained from X-ray and neutron-based methods is complementary, facilitating a comprehensive characterisation of materials, structures, and manufacturing techniques
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