Long Process Incus necrosis in Revision Stapedotomy: Retrospective Clinical Study

Objectives: We describe our experience with long process incus (LPI) necrosis in revision stapedotomy and discuss the different management methods proposed in the literature to identify surgical techniques that can lead to satisfactory results over time. Methods: Twenty-two stapedotomy revisions, in 21 patients with the necrosis of the long process of the incus, are performed from 1997 to 2017. In cases of erosion or minimal necrosis of LPI, a new prosthesis of the same type or an angled prosthesis was applied higher on the residual incus stump. In cases of partial necrosis of LPI, a Donaldson type ventilation tube reshaped and placed on the residual incus stump to stabilize prosthesis, or glass ionomer bone cement was used. In cases of subtotal necrosis of LPI, a cup piston prosthesis in polycel was applied on incus residual stump. Pre- and postoperative (≥1 year) pure tone audiometry was performed for all cases. Air conduction threshold, bone conduction (BC) threshold, and air-bone gap (ABG) were documented according to the American Academy of Otolaryngology Head and Neck Surgery Committee of Hearing and Equilibrium guidelines. Results: At 1-year follow-up, postoperative ABG was reduced to ≤10 dB in 13 (59%) cases and ≤20 dB in 19 (86.4%) cases. The mean postoperative ABG significantly decreased in each group. There was no significant change in postoperative BC thresholds, and there were no cases with postoperative SNHL. Conclusion: Excellent functional results can also be achieved in cases of long incus process necrosis. The choice of technique should be considered according to the degree of necrosis. Piston replacement with the same type or angled type prosthesis, in cases of erosion or minimal LPI necrosis, and modified Donaldson type ventilation tube, in cases of partial LPI necrosis, provided excellent hearing results

Immagine e immaginazione

Che cos’è un’immagine? E che rapporto ha con l’immaginazione? A queste domande rispondono i saggi raccolti nel volume, articolati secondo tre fondamentali linee interpretative: un approccio storico, che dà rilievo al rapporto tra immagine e immaginazione nella storia del pensiero; uno sguardo etico-politico, che mette al centro della riflessione il ruolo del binomio immagine-immaginazione nella scelta individuale o collettiva; e infine il punto di vista estetologico, che mostra la specificità della dimensione artistica, sia essa visuale o letteraria

Measurement of the muon decay spectrum with the ICARUS liquid Argon TPC

Examples are given which prove the ICARUS detector quality through relevant physics measurements. We study the muon decay energy spectrum from a sample of stopping muon events acquired during the test run of the ICARUS T600 detector. This detector allows the spatial reconstruction of the events with fine granularity, hence, the precise measurement of the range and dE/dx of the muon with high sampling rate. This information is used to compute the calibration factors needed for the full calorimetric reconstruction of the events. The Michel rho parameter is then measured by comparison of the experimental and Monte Carlo simulated muon decay spectra, obtaining rho = 0.72 +/- 0.06(stat.) +/- 0.08(syst.). The energy resolution for electrons below ~50 MeV is finally extracted from the simulated sample, obtaining (Emeas-Emc)/Emc = 11%/sqrt(E[MeV]) + 2%.Comment: 16 pages, 8 figures, LaTex, A4. Some text and 1 figure added. Final version as accepted for publication in The European Physical Journal

A study of the transverse fluctuations of hadronic showers in the NOMAD electromagnetic calorimeter

The transverse shower shape of the energy deposition of hadrons in the NOMAD lead glass calorimeter has been studied by exposing a prototype of this calorimeter to pion test beams of various momenta and incident angles. Large event to event fluctuations in the shower shape and significant energy depositions far from the incident hadron were observed making it difficult to associate all the deposited energy to the incident hadron that caused it. Since in the NOMAD detector the momenta of charged hadrons are measured by a magnetic spectrometer, such an association is necessary to be able to subtract from the calorimeter all the energy caused by the observed charged hadrons in order to avoid double counting. Probability functions based on the measurements have been developed to describe fluctuations of the lateral shower shape.\ Starting from these functions, an algorithm is developed for identifying the energy deposition associated to a charged hadron.\ The identification and separation of overlapping showers based on these functions is also discussed. The Monte Carlo simulation of the calorimeter reproduces the test beam data well therefore allowing the application of the algorithm at angles and momenta not studied in the test beam

The NOMAD experiment at the CERN SPS

The NOMAD experiment is a short base-line search for $\nu_{\mu}\rightarrow \nu_{\tau}$ oscillations in the CERN neutrino beam. The $\nu_{\tau}$'s are searched for through their charged-current interactions followed by the observation of the resulting $\tau^{-}$ through its electronic, muonic or hadronic decays. These decays are recognized using kinematical criteria necessitating the use of a light target which enables the reconstruction of individual particles produced in the neutrino interactions. This paper describes the various components of the NOMAD detector: the target and muon drift chambers, the electromagnetic and hadronic calorimeters, the preshower and transition radiation detectors, and the veto and trigger scintillation counters. The beam and data acquisition system are also described. The quality of the reconstruction of individual particles is demonstrated through the ability of NOMAD to observe K$^0_{\rm s}$'s, $\Lambda^0$'s and $\pi^0$'s. Finally, the observation of $\tau^{-}$ through its electronic decay being one of the most promising channels in the search, the identification of electrons in NOMAD is discussed

Modeling Fragmentation By Percolation In Combustion of Carbons

A 3-D model has been developed to investigate the process of combined combustion and percolative fragmentation of carbons in the intermediate regime between intraparticle diffusion and chemical kinetics control. The model is based on the discretization of the field into a cubic structure. Vacancies can be originated in the structure to build a lattice having a given original voidage and void size distribution. A Monte Carlo simulation is used to remove cells from such a lattice by combustion and percolative fragmentation. The fraction of cells removed by percolation with respect to the total number of cells removed by combustion and percolation and the distribution of volumes of percolated fragments have been calculated as functions of model variables. These include: the lattice original voidage and void size distribution, the depth of penetration of combustion and the size of the unit cell of the lattice. The simulation successfully describes carbon combustion efficiency and size distribution of carbon fines as functions of porosity and pore size distribution under conditions for both peripheral and uniform percolation, provided that an appropriate size of the unit cell is used. The choice of this variable is a difficult point in the simulation. The size of the unit cell, in fact, cannot be predicted on a general basis due to its dependence on the physical and chemical properties of the specific carbon being considered

Stability Analysis of Uniformly Fluidized-beds In Terms of the Elastic-modulus of the Dispersed Phase

Theoretical criteria defining the transition from bubble free to ordinarily bubbling beds have been examined on the basis of results of a number of experimental studies reported in the literature. It is suggested that the various theoretical approaches may be compared by considering the values of elastic modulus of the dispersed phase determined using each approach. Theoretical approaches based solely on gas-particle interactions do not generally agree with the experimental results. Further studies on the structure of constitutive equations of elastic moduli, and their validation by means of critical experiments are required to evaluate possible effects of particle to particle cohesive forces on bubble free gas fluidization