197 research outputs found

    Timing with the Galileo Open Service

    Get PDF
    The article addresses UTC dissemination through Galileo Open Service and describes the Galileo Open Service Key Performance Indicators related to timing

    Sclerotherapy for III- and IV-degree hemorrhoids: Results of a prospective study

    Get PDF
    background: In the last 2 years, anorectal surgery has been strongly affected and even surgery for urgent cases cannot be scheduled; also, patients with III- and IV-degree bleeding hemorrhoids should be treated conservatively. the aim was to evaluate the effectiveness of sclerotherapy in patients who had to postpone surgery. methods: we included all patients with III- and IV-degree bleeding hemorrhoids who underwent outpatient sclerotherapy. the visual analog scale and the hemorrhoid severity score were used at the baseline and at 4 weeks after the procedure with a telephone interview, and all patients were outpatient-evaluated 1 week, 1 month, and 1 year after the treatment. all pre- and postoperative data were recorded. results: from october 2020 to november 2021, 19 patients with III- (12 patients; 63%) and IV-degree (7 patients; 37%) bleeding hemorrhoids were enrolled. the mean operative time was 4.5 min, and no intraoperative complications occurred. one case of tenesmus and three failures were detected. six months after the procedure, the overall success rate was 84%, although all of the patients enrolled reported persistent bleeding at the end of the study period. of these, 5 patients (26%) were scheduled for surgery and 11 patients (58%) refused surgery and asked to undergo a re-do sclerotherapy. conclusion: sclerotherapy with 3% polidocanol foam is a safe and effective procedure also in III- and IV-degree bleeding hemorrhoids. the long-term data on the length of the foam remain to be evaluated in additional studies

    Unification of gravity, gauge fields, and Higgs bosons

    Full text link
    We consider a diffeomorphism invariant theory of a gauge field valued in a Lie algebra that breaks spontaneously to the direct sum of the spacetime Lorentz algebra, a Yang-Mills algebra, and their complement. Beginning with a fully gauge invariant action -- an extension of the Plebanski action for general relativity -- we recover the action for gravity, Yang-Mills, and Higgs fields. The low-energy coupling constants, obtained after symmetry breaking, are all functions of the single parameter present in the initial action and the vacuum expectation value of the Higgs.Comment: 12 pages, no figures. v2 minor correction

    Unification of gravity, gauge fields and Higgs bosons

    Get PDF
    Abstract We consider a diffeomorphism invariant theory of a gauge field valued in a Lie algebra that breaks spontaneously to the direct sum of the spacetime Lorentz algebra, a Yang-Mills algebra, and their complement. Beginning with a fully gauge invariant action -an extension of the Plebanski action for general relativity -we recover the action for gravity, Yang-Mills, and Higgs fields. The low-energy coupling constants, obtained after symmetry breaking, are all functions of the single parameter present in the initial action and the vacuum expectation value of the Higgs

    Unification of gravity, gauge fields and Higgs bosons

    Get PDF
    Abstract We consider a diffeomorphism invariant theory of a gauge field valued in a Lie algebra that breaks spontaneously to the direct sum of the spacetime Lorentz algebra, a Yang-Mills algebra, and their complement. Beginning with a fully gauge invariant action -an extension of the Plebanski action for general relativity -we recover the action for gravity, Yang-Mills, and Higgs fields. The low-energy coupling constants, obtained after symmetry breaking, are all functions of the single parameter present in the initial action and the vacuum expectation value of the Higgs

    FePc Adsorption on the Moir\'e Superstructure of Graphene Intercalated with a Co Layer

    Get PDF
    The moir\'e superstructure of graphene grown on metals can drive the assembly of molecular architectures, as iron-phthalocyanine (FePc) molecules, allowing for the production of artificial molecular configurations. A detailed analysis of the Gr/Co interaction upon intercalation (including a modelling of the resulting moir\'e pattern) is performed here by density functional theory, which provides an accurate description of the template as a function of the corrugation parameters. The theoretical results are a preliminary step to describe the interaction process of the FePc molecules adsorption on the Gr/Co system. Core level photoemission and absorption spectroscopies have been employed to control the preferential adsorption regions of the FePc on the graphene moir\'e superstructure and the interaction of the central Fe ion with the underlying Co. Our results show that upon molecular adsorption the distance of C atoms from the Co template mainly drives the strength of the molecules-substrate interaction, thereby allowing for locally different electronic properties within the corrugated interface.Comment: This document is the Accepted Manuscript version of a Published Work that appeared in final form in J. Phys. Chem. C , copyright \c{opyright} American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.jpcc.6b0987

    TCNQ physisorption on the Bi2Se3 topological insulator

    Get PDF
    Topological insulators are promising candidates for spintronic applications due to their topologically protected, spin-momentum locked and gapless surface states. The breaking of the time-reversal symmetry after the introduction of magnetic impurities, such as 3d transition metal atoms embedded in two-dimensional molecular networks, could lead to several phenomena interesting for device fabrication. The first step towards the fabrication of metal-organic coordination networks on the surface of a topological insulator is to investigate the adsorption of the pure molecular layer, which is the aim of this study. Here, the effect of the deposition of the electron acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules on the surface of a prototypical topological insulator, bismuth selenide (Bi2Se3), is investigated. Scanning tunneling microscope images at low-temperature reveal the formation of a highly ordered two-dimensional molecular network. The essentially unperturbed electronic structure of the topological insulator observed by photoemission spectroscopy measurements demonstrates a negligible charge transfer between the molecular layer and the substrate. Density functional theory calculations confirm the picture of a weakly interacting adsorbed molecular layer. These results reveal significant potential of TCNQ for the realization of metal-organic coordination networks on the topological insulator surface

    Electronic structure of few-layer black phosphorus from μ\mu-ARPES

    Full text link
    Black phosphorus (BP) stands out among two-dimensional (2D) semiconductors because of its high mobility and thickness dependent direct band gap. However, the quasiparticle band structure of ultrathin BP has remained inaccessible to experiment thus far. Here we use a recently developed laser-based micro-focus angle resolved photoemission (μ\mu-ARPES) system to establish the electronic structure of 2-9 layer BP from experiment. Our measurements unveil ladders of anisotropic, quantized subbands at energies that deviate from the scaling observed in conventional semiconductor quantum wells. We quantify the anisotropy of the effective masses and determine universal tight-binding parameters which provide an accurate description of the electronic structure for all thicknesses.Comment: Supporting Information available upon reques
    corecore