832 research outputs found
Axillary lymphectomy in breast cancer.
No full textThe aim of the study was to demonstrate the prognostic value of sentinel node biopsy compared to the sampling of clinically suspected nodes and lymphectomy of the 3 axillary levels. METHODS. From October 1996 to January 1999, 60 patients with breast cancer with a diameter of 4 cm or under using different procedures of axillary lymphadenectomy. Sentinel node biopsy was performed using Giuliano's technique, followed by lymph nodes larger than 5 cm (lymph node sampling) and lastly all axillary lymph nodes (axillary lymphectomy at 3 levels). Sentinel nodes were identified in all patients and a mean of 3 sentinel nodes (range 1-5) were removed during the procedure. Histological analysis showed metastatic sentinel nodes in 21 cases. Lymph node sampling was possible in 43 patients who presented enlarged nodes. The mean number of lymph nodes removed was 6 (range 3-10). Lymph node metastasis was found in 10 patients and of these 7 had a metastatic sentinel node, whereas 3 had presented negative results. Histological tests in all 60 cases of complete axillary lymphectomy showed positive results in 4 cases confirming metastasis present in sentinel nodes. The results show that the association of lymph node sampling can improve the efficacy of sentinel node dissection, highlighting the rare cases of false negatives. In our study, total axillary lymphectomy did not add any information to the N parameter and was resolutive in a small percentage of cases
[Ambulatory surgical treatment for breast carcinoma].
No full textThe aim of the study is to demonstrate the feasibility and the oncologic effectiveness of quadrantectomy plus sentinel node biopsy performed under local anesthesia, and to demonstrate the economic and psychologic advantages. From October 1996 to March 2000, 71 patients affected with clinical T1 N0 breast cancer, underwent quadrantectomy or tumor resection plus sentinel node biopsy and clinically suspicion axillary nodes biopsy, under local anesthesia at the Casa di Cura "Villa Mafalda" in Rome. Twenty tumors were T1a, 26 T1b e 25 T1c. A mean of 2 sentinel nodes (range 1-4) and a mean of 8 axillary nodes were removed during the procedure. In 2 cases sentinel nodes were not identified. Intraoperative histologic examination showed metastatic sentinel nodes in 11 cases. An axillary node dissection was performed in all cases (>12 nodes) and no other metastatic nodes were found. In all patients clinically suspected nodes were removed. In two cases no evidence of metastasis was found in sentinel nodes, while histologic examination revealed in a patient micrometastasis in one node, and in another patient two metastatic nodes. Fifty-three patients rated the overall surgical, anesthetic and recovery experience as "very satisfactory", 13 "satisfactory" and 5 "unsatisfactory". Patients typically expressed their pleasure at the possibility to return home and stressed the ease of recovery
Carlo G. Cereti, Youssef Moradi, Cyrus Nasrollazadeh. A Collection of Sasanian clay sealings preserved in the Takiya-e Mo’āven al-Molk of Kermanshah
No full textLa collection étudiée ici compte 49 bulles sassanides, la majorité provenant d’une saisie. Quelques-unes auraient été trouvées dans les fouilles de Kangāvar, mais il est impossible de savoir lesquelles (voir à ce propos : C. G. Cereti et Z. Bassiri, « On a Few Sasanian Bullae from the Collections of the National Museum of Iran », in : R. Gyselen, ed., Words and symbols: Sasanian Objects and the Tabarestān Archive [Res Orientales XXIV], 2016, p. 17, n° 16 : bulle administrative provenant des f..
Electromagnetic Wave Propagation and Radiation in Chiral Media
No full textPropagation and radiation of electromagnetic waves in a lossless, reciprocal, chiral medium is studied in this thesis. Such a medium is described electromagnetically by the constitutive relations D = εE + iγB and H = iγE + (1/µ)B. The constants ε, µ, γ are real and have values that are fixed by the size, shape, and the spatial distribution of the elements that collectively compose the medium. The plane wave propagation in an unbounded chiral medium is considered. The propagation constants are obtained and the polarization properties of electromagnetic waves in such a medium are discussed in detail. The problem of reflection from, and transmission through a semi-infinite chiral medium is solved by obtaining the Fresnel equations. The conditions for the total internal reflection of the incident wave from the interface, and the existance of the Brewster angle are obtained. The effects of the chirality on the polarization and intensity of the reflected wave from the chiral half-space are discussed and illustrated by employing the Stokes parameters. The propagation of electromagnetic waves through an infinite slab of chiral medium is formulated for oblique incidence and solved analytically for the case of normal incidence. The radiation emitted by an oscillating dipole in an unbounded, lossless, chiral medium is calculated. From the constitutive relations and from the time-harmonic Maxwell equations ∇ x E = iωB and ∇ x H = J - iωD, it is seen that the wave equation for such a medium is given by ∇ x ∇ x E - ω2µεE - 2ωµγ∇ x E = iωµJ where the source term J is the current density of the oscillating dipole and where E is the electric vector of the radiated field. The desired solution of this wave equation is found by the dyadic Green's function method, that is, by first constructing the dyadic Green's function Γ and then evaluating the expression E = iωµ∫Γ(r,r')•J(r')dV'. The dyadic Green's function Γ and the components of the radiated electric field E are obtained in closed form. The components of the radiated B, D, and H fields can be derived from knowledge of E by using the Maxwell equation B = (1/iω)∇ x E and the constitutive relations. The wave impedance of the medium and the radiation resistance of the dipole are also obtained. The effects of the chiral medium on the polarization and intensity of the dipole radiation are discussed.</p
Investigating the medium range order in amorphous Ta<sub>2</sub>O<sub>5</sub> coatings
No full textIon-beam sputtered amorphous heavy metal oxides, such as Ta2O5, are widely used as the high refractive index layer of highly reflective dielectric coatings. Such coatings are used in the ground based Laser Interferometer Gravitational-wave Observatory (LIGO), in which mechanical loss, directly related to Brownian thermal noise, from the coatings forms an important limit to the sensitivity of the LIGO detector. It has previously been shown that heat-treatment and TiO2 doping of amorphous Ta2O5 coatings causes significant changes to the levels of mechanical loss measured and is thought to result from changes in the atomic structure. This work aims to find ways to reduce the levels of mechanical loss in the coatings by understanding the atomic structure properties that are responsible for it, and thus helping to increase the LIGO detector sensitivity. Using a combination of Reduced Density Functions (RDFs) from electron diffraction and Fluctuation Electron Microscopy (FEM), we probe the medium range order (in the 2-3 nm range) of these amorphous coatings
Local and correlated studies of humidity-mediated ferroelectric thin film surface charge dynamics
No full textElectrochemical phenomena in ferroelectrics are of particular interest for catalysis and sensing applications, with recent studies highlighting the combined role of the ferroelectric polarisation, applied surface voltage and overall switching history. Here, we present a systematic Kelvin probe microscopy study of the effect of relative humidity and polarisation switching history on the surface charge dissipation in ferroelectric Pb(Zr0.2Ti0.8)O3 thin films. We analyse the interaction of surface charges with ferroelectric domains through the framework of physically constrained unsupervised machine learning matrix factorisation, Dictionary Learning, and reveal a complex interplay of voltage-mediated physical processes underlying the observed signal decays. Additional insight into the observed behaviours is given by a Fitzhugh–Nagumo reaction–diffusion model, highlighting the lateral spread and charge passivation process contributors within the Dictionary Learning analysis.The authors acknowledge Dr Sergei V. Kalinin of Oak Ridge National Laboratory, for
helpful discussions about machine learning and the initial suggestion to explore
reaction–diffusion modelling. This work was supported by Division II of the Swiss
National Science Foundation under project 200021_178782. A.V. acknowledges
support by the Spanish Government under the project PID2019-110907GB-I00 and
the “Severo Ochoa” Program for Centres of Excellence in R&D (CEX2019-000917-S).
N.D. acknowledges support by the Spanish Government under the project PID2019-
109931GB-I00. N.B.G. acknowledges support by the National Science Foundation
under the project DMR-20269676. The authors would like to thank S. Muller for
technical support.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe
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