197 research outputs found
Timing with the Galileo Open Service
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
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
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
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
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
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
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 -ARPES
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 (-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
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