2,352 research outputs found

    LA STIMOLAZIONE DEL NERVO FACCIALE DOPO LA PROCEDURA DI IMPIANTO COCLEARE

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    La stimolazione del nervo faciale (FNS) è una delle complicanze più comuni e meglio conosciute della procedura di impianto cocleare. Alcune condizioni come l’otosclerosi, le malformazioni cocleari ma anche gli elevati livelli di stimolazione, che possono essere necessari in pazienti con lunga deprivazione uditiva, sottopongono i pazienti ad un maggior rischio di sviluppare la FNS. Questa può essere trattata mediante minime modifiche nel fitting post-operatorio con talvolta una riduzione delle performance uditive. In questa tesi si discutono retrospettivamente le caratteristiche cliniche di 11 pazienti (su un gruppo di 119 impiantati dal 1999 al 2007 presso la clinica ORL dell’Università di Pisa) che hanno sviluppato la stimolazione del nervo facciale

    An underwater acoustic positioning system based on buoys with GPS

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    This thesis proposes several solutions to the problem of estimating the position of an underwater vehicle. The commercial system adopted for collecting data consists of four buoys that compute the times of arrival (TOA) of the acoustic signals emitted periodically by a pinger installed on-board the target (so called G.I.B. system). The solutions discussed are grouped in two family of algorithms: instantaneous positioning (static) algorithms and filtering (dynamic) algorithms. For the static group, the Trilateration problem is discussed in depth, yielding closed form and iterative solutions. A detailed discussion of the estimation accuracy of the algorithms is presented. For the dynamic group, an EKF based on a simple kinematic model of the target was introduced. In order to test the algorithms proposed with real data from sea trials an initialization procedure was implemented. The procedure provides a initial fix that lies inside a certain confidence region. The filtering algorithms can be dramatically affected by outliers. Thus, an on-line measurement validation was also introduced. A Matlab-based graphical user interface was designed in order to test the algorithms described with real data obtained during sea experiments

    The novel serine protease PreR-Co promotes endothelium-independent vasorelaxation in rabbit aortic rings

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    The effect of a novel enzyme (PreR-Co) that activates renal prorenin was studied on rabbit aortas with and without endothelium. It was tested 1) in the basal tone of nonstimulated or ANG II-sensitized rings or rings precontracted with norepinephrine (NE), PGF(2alpha), high KCl concentration, and 2) in rings pretreated with enalaprilat, losartan, PD-123319, N(omega)-nitro-l-arginine methyl ester, HOE-140, indomethacin, or serine protease inhibitors (PMSF, aprotinin, or soybean trypsin inhibitor); kallilkrein and bradykinin were also tested in ANG II-sensitized rings. PreR-Co produced a vasorelaxant effect in the basal tone and in the precontracted rabbit aorta. The effect was endothelium independent, potentiated by endothelium removal or nitric oxide (NO) synthase inhibition, and abolished by boiling the enzyme. In addition, the effect improved when basal tone was increased in ANG II-sensitized aortic rings or in precontracted vessels. No activation of the ANG II, bradykinin, prostaglandin, or NO pathway mediating the PreR-Co response could be obtained, suggesting a direct action of the enzyme. This action seems to be dependent on esterasic activity because serine protease inhibitors like PMSF and aprotinin were able to block the vasorelaxant effect of PreR-Co.Fil: Peral, Maria de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Vincent, Paula Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Romano, Monica Liliana. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Guardia, Dora Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Coviello, Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: de Vito, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentin

    A New Surgical Approach for Direct Acoustic Cochlear Implant: A Temporal Bone Study

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    The direct acoustic cochlear implant (DACI) is among the latest developments in the field of implantable acoustic prostheses. The surgical procedure requires a mastoidectomy and a posterior-inferior tympanotomy, with access to the facial recess at the level of the oval window, in a complex and lengthy surgical approach. Here, we report a new and considerably shorter surgical approach

    Cochlear implant in incomplete partition type I

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    In this investigation, we report on 4 patients affected by incomplete partition type I submitted to cochlear implant at our institutions. Preoperative, surgical, mapping and follow-up issues as well as results in cases with this complex malformation are described. The cases reported in the present study confirm that cochlear implantation in patients with incomplete partition type I may be challenging for cochlear implant teams. The results are variable, but in many cases satisfactory, and are mainly related to the surgical placement of the electrode and residual neural nerve fibres. Moreover, in some cases the association of cochlear nerve abnormalities and other disabilities may significantly affect results

    Drug-Induced Sleep Endoscopy: Clinical Application and Surgical Outcomes

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    The visualization of the level and pattern of apnea and hypopnea events is of pivotal importance in the diagnosis and therapeutic decision-making for sleep-disordered breathing (SDB). There are numerous techniques available to assess upper airway obstruction, which include imaging, acoustic analysis, pressure transducer recording, and endoscopic evaluation. Drug-induced sleep endoscopy (DISE) is a diagnostic tool that allows the dynamic, three-dimensional evaluation of the patterns of vibration and collapse of the upper airway of SDB patients. DISE may change the initial surgical planning in a high percentage of cases. A universally accepted and methodologically standardized DISE could provide significant insight into its role to improve surgical outcomes. However, up to now the ideal DISE protocol remains an open question

    Sistema de medición de campo lejano

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    El Programa Espacial Argentino de la Comisión Nacional de Actividades Espaciales (CONAE) ha obtenido buenos resultados con métodos asociativos, que permiten a todos los países participantes de una misión argentina reducir sus costos de acceso y operación en el espacio. Esto, más una ingeniería de muy buena calidad y costos de construcción muy moderados han hecho que las agencias espaciales de los Estados Unidos, Francia, Italia, Dinamarca y Brasil colocarán sus aparatos o servicios en satélites argentinos. Y hay más interesados. Por su disposición para las alianzas estratégicas y el funcionamiento impecable de sus misiones (que van desde el diseño de la plataforma a la fabricación de sus partes, y desde la integración final de éstas hasta el control del satélite ya instalado en órbita), la Argentina empieza a ser vista como un socio espacial confiable -o posible- por muchos países desarrollados.Tesis digitalizada en SEDICI gracias a la colaboración de la Biblioteca de la Facultad de Informática.Facultad de Informátic

    Sistema de medición de campo lejano

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    El Programa Espacial Argentino de la Comisión Nacional de Actividades Espaciales (CONAE) ha obtenido buenos resultados con métodos asociativos, que permiten a todos los países participantes de una misión argentina reducir sus costos de acceso y operación en el espacio. Esto, más una ingeniería de muy buena calidad y costos de construcción muy moderados han hecho que las agencias espaciales de los Estados Unidos, Francia, Italia, Dinamarca y Brasil colocarán sus aparatos o servicios en satélites argentinos. Y hay más interesados. Por su disposición para las alianzas estratégicas y el funcionamiento impecable de sus misiones (que van desde el diseño de la plataforma a la fabricación de sus partes, y desde la integración final de éstas hasta el control del satélite ya instalado en órbita), la Argentina empieza a ser vista como un socio espacial confiable -o posible- por muchos países desarrollados.Tesis digitalizada en SEDICI gracias a la colaboración de la Biblioteca de la Facultad de Informática.Facultad de Informátic

    Drug-Induced Sleep Endoscopy: Technique, Indications, Tips and Pitfalls

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    Drug-induced sleep endoscopy (DISE) is a diagnostic tool to assess the upper airway of snorers and obstructive sleep apnea patients in conditions that mimic natural sleep. Although DISE appears simple and similar to awake endoscopy, there are many aspects that need to be standardized in order to obtain reliable and reproducible information. In this article, we will recommend how to reliably perform DISE, its indications, and how to obtain and interpret the information of the upper airway
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