84 research outputs found

    Long Process Incus necrosis in Revision Stapedotomy: Retrospective Clinical Study

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    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

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

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    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

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    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

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    The NOMAD experiment is a short base-line search for νμ→ντ\nu_{\mu}\rightarrow \nu_{\tau} oscillations in the CERN neutrino beam. The ντ\nu_{\tau}'s are searched for through their charged-current interactions followed by the observation of the resulting τ−\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 Ks0^0_{\rm s}'s, Λ0\Lambda^0's and π0\pi^0's. Finally, the observation of τ−\tau^{-} through its electronic decay being one of the most promising channels in the search, the identification of electrons in NOMAD is discussed

    Studi greci e latini per Giuseppina Matino

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    This volume contains twenty-nine essays on Greek and Latin texts, presented to the renowned Hellenist Giuseppina Matino by members of the ‘Sciences of Antiquity’ Unit at the Department of Humanities of the University Federico II in Naples. The papers range from Greek language and literature to Latin language and literature, classical philology, papyrology, humanistic Latin literature, Byzantine philology, and classical reception. Such a variety of subjects reflects the multiple research fields that are being pursued at the ‘Sciences of Antiquity’ Unit, of which Giuseppina Matino has been in charge during the latest years of her academic career

    Simplified numerical modelling of structural units into masonry building compounds: An equivalent frame method based approach

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    Historical centres are often constituted of assemblages of un-engineered masonry building compounds very vulnerable to exceptional actions like earthquakes. Building codes do not foresee methods to predict their static non-linear behaviour. This paper propose a simplified modelling approach to predict the seismic response of structural units into masonry building compounds. This approach is based on the Equivalent Frame Method modelling EFM), a technique implemented within a Finite Element Method (FEM) calculation program. The modelling technique has been applied to investigate a simple building compound representative of Southern Italy building aggregates erected during the past decades. Firstly, the whole aggregates have been modelled and analysed in order to evaluate the seismic behaviour of each structural units. Later on, the seismic response of these structural units has been assessed by modelling the single units as isolated structures with boundary conditions applied to consider, in a simplified way, their position in the aggregate and, therefore, the influence of other constructions. Finally, comparison of the achieved results has been carried out in order to confirm the effectiveness of the proposed analyses approach

    Intravascular Papillary Endothelial Hyperplasia (Masson's Tumor) of the Supraclavicular Region: Management of a Rare Case

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    Objective: Rare diseaseBackground: Masson's tumor, also known as IPEH (intravascular papillary endothelial hyperplasia), is a rare benign vascular process, comprising approximately 2% of vascular tumors of the skin and subcutaneous tissue. IPEH presenting as a neck mass is rare, with only 5 reports of anterior neck mass and 7 cases of lateral neck lesions, of which 1 was in an external jugular vein aneurysm. To the best of our knowledge, the localization of intravascular papillary endothelial hyperplasia in the supraclavicular region is rarely reported.Case Report: We describe our management of a non-traumatic and non-painful mass on the right supraclavicular region in 24-year-old woman. Ultrasound revealed a heterogeneously hypoechoic mass with intense vascularization. Magnetic resonance imaging (MRI) showed a formation with lobulated contours and closely related to muscular layers of serratus anterior muscle. The findings of ultrasound-guided biopsy (FNA) were inconclusive. Complete removal of the mass was performed. Histopathological examination showed a well-circumscribed lesion with numerous small papillary structures. The papillae had hyalinized hypocellular cores covered by flattened endothelium. Immunohistochemical analysis showed endothelial positivity for CD34 and CD31. These features are typical of IPEH. No recurrence had occurred at 12 months after surgery. Conclusions: The differential diagnosis of malignant tumors like angiosarcoma is important because the prognosis significantly differs. Surgical excision is the treatment of choice. In our experience, the size of the lesion and its critical landmarks have not influenced the outcomes of the surgical procedure in terms of potential functional damages
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