44 research outputs found
Manutenzione e messa in sicurezza di opere di difesa delle valanghe
A partire dagli anni 80 lungo i versanti in destra e sinistra orografica, che insistono sul valico del Brennero tra Italia ed Austria, sono state realizzate complesse ed articolate opere di difesa dalle valanghe, a protezione della rete stradale, autostradale e ferroviaria. Le opere di difesa sono disposte lungo filari che si sviluppano complessivamente per oltre 40 chilometri e sono state oggetto negli ultimi anni di diffusi interventi di manutenzione e messa in sicurezza a causa di dissesti con crolli di vari metri cubi e movimenti con spostamenti che in alcune aree arrivano ad alcuni centimetri all\u2019anno, che interessano la coltre superficiale di degradazione del substrato roccioso metamorfico dello spessore variabile da 1 a 3 metri che hanno coinvolto numerose strutture di protezione dalle valanghe. Le fondazioni delle opere a seconda della tipologia costruttiva a suo tempo adottata sono di tipo diretto oppure su micropali. Le cause dei dissesti sono legate alla natura e caratteristiche della copertura, lungo versanti fortemente inclinati (35\ub0\uf745\ub0), ed alla concomitanza con eccessi di pressioni neutre dovuti a flussi d\u2019acqua concentrati nel momento dello scioglimento delle masse nevose accumulate che alterano il naturale regime idrogeologico
Prolungata remissione della sintomatologia infettiva durante il trattamento con ascorbato in un caso di sindrome di Chediak-Wigashi
A new paramyotonia congenita SCN4A mutation in domain I-S5 of the sodium channel suggests novel regions involved in channel inactivation.
Large scale hydraulic conductivity of the soil deposits of the Venezia Lagoon from numerical back analysis
In the framework of the Mo.S.E. (Electro-mechanical Experimental Module) project for the safeguard of the city of Venezia, an 8.7 m deep basin is being used in the provisional stage for gate caissons precasting. The basin perimeter embankment is delimited by a cofferdam realised by sheet piling on the sea side, and by a CSM (Cutter Soil Mixing) diaphragm wall on the land side. Dewatering operations lasted about 5 months to reach the steady state regime, and they affected the silty foundation deposits which were partially desaturated. The results of FEM numerical analyses of the dewatering operations are presented, focusing on the hydraulic regime and groundwater control. A non-linear analysis was performed, accounting for desaturation of the upper deposit layers, promoted by the dewatering operations. Parametric analyses were run to analyse the effects of hydraulic conductivities ratios and of their absolute values on the dewatering operations. The comparison between recorded data and numerical results allowed for the determination of the large scale hydraulic conductivities of the Venetian deposits, and showed the role played by anisotropy and possible non homogeneous permeability of the barriers on the performance of the cofferdam
Large scale hydraulic conductivity of the soil deposits of the Venezia Lagoon from numercial back-analysis
Stapes malformations: the contribute of the endoscopy for diagnosis and surgery
The aim of this study is to investigate the contribute of the endoscopic exclusive transcanalar approach for the management of stapes malformations. A retrospective chart review was made at our tertiary referral centers. 17 patients with stapes malformations underwent surgery with endoscopic exclusive transcanal approach. A complete audiological and radiological assessment before and after surgery was performed. 12/17 (70 %) underwent a surgical endoscopic correction, In case of fixed platina underwent five endoscopic stapedotomy and one endoscopic stapedectomy were performed. In case of mobile platina five endoscopic ossiculoplasties with partial ossiculoplasty replacement prosthesis were performed, 3 with autologous remodeling incus and 2 with malleus head remodeling. In 1 case, only an endoscopic stapes mobilization was made. In 5/17 (30 %), due to difficult anatomical findings an endoscopic explorative tympanotomy was finally performed. The mean preoperative air conduction (AC), bone conduction (BC) and air-bone gap (ABG) were, respectively, 60.7, 26.3 and 34.4 dB. The mean postoperative AC, BC and ABG were, respectively, 33.8, 26.5 and 7.3 dB, with a mean improvement of the ABG of 27.1 dB. Discharge from hospital was on the first post-surgery day. No relevant postoperative complications were noted. The median follow-up was 3.6 years (range 1\u20136). The endoscopic approach results very adequate for the diagnosis and treatment of stapes malformations, checking variations of the ossicles conformation and functioning and performing safe surgery, under direct control of middle ear structures
Round window chamber and fustis: endoscopic anatomy and surgical implications
The round window region is of critical importance in the anatomy of the middle ear. The aim of this paper is to describe its anatomy from an endoscopic point of view, emphasizing structures that have important surgical implications, in particular the fustis and the subcochlear canaliculus. The fustis, a smooth bony structure that forms the floor of the round window region, is a constant and important structure. It seems to indicate the round window membrane and the correct position of scala tympani. A structure connecting the round window region to the petrous apex, named the subcochlear canaliculus, is also described. A retrospective review of video recordings of endoscopic dissection and surgical procedures, carried out between June 2014 and February 2015, was conducted across two Tertiary university referral centers. A total of 42 dissections were analyzed in the study. We observed the fustis in all the cases and we identify two different anatomical conformations. The subcochlear canaliculus was found in 81.0 %, with a pneumatization direct to the petrous apex in 47.7 %. Conformation and limits of the round window niche may influence the surgical view of the round window membrane. Endoscopic approaches allow a very detailed view, which enables a comprehensive exploration of the round window region. Accurate knowledge of the anatomical relationships of this region has important advantages during middle ear surgery