16 research outputs found
W-Shaped Osteotomy to Avoid Paranasal Deformity After Standard Le Fort I in Orthognathic Surgery
When occlusal alterations are not accompanied by paranasal deficiencies, mobilization of the maxilla via Le Fort I osteotomy should be made with a different design. In this preliminary report, a W-shaped osteotomy that doesn't change the position of the maxillary bone surrounding the pyriform aperture was presented for the first time. Advantages and indications of this new procedure are discussed
A rare location of angiofibroma in the lateral crus of the alar cartilage
Juvenile angiofibromas (JNA) are common benign tumors usually occurring in the nasopharynx of male adolescents. They represent 0.5% of head and neck neoplasms and very rarely they localize in extra-nasopharyngeal sites. Extra-nasopharyngeal angiofibroma (ENPA) is histologically similar to JNA. Due to its clinical and epidemiological characteristics, some authors identify the ENPA as a different disease from the typical JNA. Less than a hundred cases of ENPA are reported in literature. Maxillary and ethmoid sinus are the most commonly involved sites, whereas other localizations such as nasal septum and inferior turbinate are infrequent. We report the case of a ENPA arising from the lateral crus of the alar cartilage, the first described in literature, at the best of our knowledges.Juvenile angiofibromas (JNA) are common benign tumors usually occurring in the nasopharynx of male adolescents. They represent 0.5% of head and neck neoplasms and very rarely they localize in extra-nasopharyngeal sites. Extra-nasopharyngeal angiofibroma (ENPA) is histologically similar to JNA. Due to its clinical and epidemiological characteristics, some authors identify the ENPA as a different disease from the typical JNA. Less than a hundred cases of ENPA are reported in literature. Maxillary and ethmoid sinus are the most commonly involved sites, whereas other localizations such as nasal septum and inferior turbinate are infrequent. We report the case of a ENPA arising from the lateral crus of the alar cartilage, the first described in literature, at the best of our knowledges
Segmental sandwich osteotomy and tunnel technique for three-dimensional reconstruction of the jaw atrophy: a case report
Abstract Background A three-dimensionally favourable mandibular bone crest is desirable to be able to successfully implant placement to meet the aesthetic and functional criteria in the implant-prosthetic rehabilitation. Several surgical procedures have been advocated for bone augmentation of the atrophic mandible, and the sandwich osteotomy is one of these techniques. The aim of the present case report was to assess the suitability of segmental mandibular sandwich osteotomy combined with a tunnel technique of soft tissue. Based on our knowledge, nobody described before the sandwich osteotomy with tunnel technique to improve the healing of the wound and meet the dimensional requirements of preimplant bone augmentation in cases of a severely atrophic mandible. Case presentation A 59-year-old woman with a severely atrophied right mandible was treated with the sandwich osteotomy technique filled with autologous bone graft harvested by a cortical bone collector from the ramus. Clinical examination revealed that the mandible was edentulous bilaterally from the first molar to the second molar region. Radiographically, atrophy of the mandibular alveolar ridge in the same teeth site was observed. We began to treat the right side. A horizontal osteotomy of the edentulous mandibular bone was then made with a piezoelectric device after tunnel technique of the soft tissue. The segmental mandibular sandwich osteotomy (SMSO) was finished by two (mesial and distal) slightly divergent vertical osteotomies. The entire bone fragment was displaced cranially, and the desirable position was obtained. The gap was filled completely with autologous bone chips harvested from the mandibular ramus through a cortical bone collector. No barrier membranes were used to protect the grafts. The vertical incisions were closing with interruptive suturing of the flaps with a resorbable material. In this way, the suture will not fall on the osteotomy line of the jaw; the result will be a better predictability of soft and hard tissue healing. Conclusions Segmental mandibular sandwich osteotomy is an easy and safety technique that could be performed in an atrophic posterior mandible. Future studies involving long-term follow-up are needed to evaluate the permanence of these results
NAVIGATION MESSAGE AUTHENTICATION FOR NEXT GENERATION GNSS
Since the early days of GNSS, one of the main issues has been the need to protect the final user from attackers trying to
emulate the data sent by the real system, the so-called spoofers. This can be done in particular adding the system the
function of navigation message authentication, that represents the subject of this paper.
The paper introduces a general approach to the problem, to come to a detailed real-world in-orbit case, that is the
Galileo Navigation System. This kind of authentication feature is in fact foreseen for the evolution of the system
towards its own second generation, evolution that is currently ongoing.
Recent research (performed by Wiser and TASI in the frame of internal R&D activities) within the GNSS evolution
study for Galileo Second Generation as well as GPS evolution, are investigating the possibility to have a more robust
and reliable signal through the broadcasting of navigation message authentication bits. The paper
describes a possible solution to the problems wherein the authentication bits are included in a dedicated channel that is
added on top of the current signal-in-space format using IBOC multiplexing. This represents an alternative solution to
the standard idea of reserving some bits of the current navigation message for authentication.
The advantage of the dedicated channel is relatively clear: the bit-rate dedicated to authentication is considerably larger
than that resulting from the reserved bits in the current message, thus providing a higher security level, and lower time
to first authenticated fix (TTFA)/time between authentication (TBA). This allows in particular to easily meet the latest
recommendations stating that (at least) a security equivalent to a symmetric algorithm with 128-bit key is needed.
Concerning the authentication algorithm, the present study proposes a combination of the TESLA protocol with a
public-key protocol (such as ECDSA). This allows to improve on a weakness of TESLA that requires time
synchronization: albeit loos, it cannot guaranteed at receiver start-up, and in addition the TESLA root key shall be
authenticated anyway. The optimal combination is found based on a trade-off between security strength, bandwidth
overhead, authentication error rate, and time between authentication.
Our proposal may pave the way towards an Open Service Navigation Message Authentication (NMA) solution to be
broadcast on future GNSS signal channel using IBOC multiplexing solution. The proposed NMA criteria are based on
the mutual combination of Elliptic Curve Digital Signature Algorithm (ECDSA) and TESLA authentication protocol.
NAVITEC 2018
The solution foresee the use of ECDSA in a first phase when time synchronization between the sender and the recipient
is not available, to switch afterwards TESLA when time synchronization is achieved.
The paper concentrates on a specific solution wherein iBOC multiplexing on the E1 channels is supplemented with
NMEA. This feasibility assessment is just a case study to show the generality of the approach and does not preclude any
other implementation for future GNSS signals.
The paper is organized as follows: first a summary of the authentication protocols are provided, focusing on the TESLA
one, and the IBOC multiplexing scheme for GNSS evolution signals. Then a proposed solution is detailed, together with
associated performance, and finally the conclusions are draw
WIDEBAND MATCHED VOLTERRA MODELING OF HIGH-POWER AMPLIFIERS FOR SATELLITE NAVIGATION AND COMMUNICATION PAYLOADS
The increasing demand in the communication and navigation satellite industry for i) greater
throughput, ii) flexibility in terms of signal generation, iii) higher efficiency, iv) improved payload reconfigurability, has generated the need to develop more accurate simulation/emulation payload
models. Inaccurate modelling of payload elements induces a non-negligible risk of over- or underdesigned elements as well as an incorrect prediction of the main KPIs derived from
emulation/simulation tools. Therefore, assessing the accuracy of currently used models and
possibly developing new, more accurate ones turns out to be an essential feature of new-generation
system design tools to derive accurate performance metrics, to enable correct dimensioning of all
system features, to better specify budget parameters (in particular equipment specifications), and
to efficiently support engineers in payload design.
In this respect, High-Power Amplifiers (HPAs) are very sensitive components within the overall
payload architecture, because they are non-linear devices that behave differently depending on the
input signal features such as occupied bandwidth, average power, Peak-to-Average Power Ratio
(PAPR), etc..
Extensive measurement and characterization activities on such devices performed in Thales-Alenia
Spacelaboratories on GNSS payloads suggested that the standard narrowband/memoryless model
of an HPA (i.e., AM/AM and AM/PM characteristics) is not sufficiently representative to derive
accurate results concerning (next generation) GNSS signals featuring bandwidth up to 100 MHz or
more, especially in terms of the in-band and out-of-band distortions actually introduced by this
element. Such inaccuracy, initially considered insignificant, turned out to be not negligible when the
payload simulation model is used to define and optimize the specifications as well the on-board
Navigation Signal Generation Unit (NSGU) design.
These conclusions led us to carry out an extensive review of the state of art of wideband HPA
models, in particular Wiener, Hammerstein and Volterra one, comparing their accuracy, efficiency
and easiness of application to real-world devices.
This analysis focuses on the Volterra model, which is usually considered too complicated and hard
to be actually tailored to a specific device. In this study, both the issues were tackled: first, how to
match the numerous parameters of the nonlinear model to the wideband Device Under Test (DUT)
has been considered. Then, a way to reduce the number of significant parameters to be derived
from the measurements activity has been defined, in order to guarantee a computationally
manageable effort without sacrificing modelling accuracy.
Starting from the lab characterization of a specific DUT operating in the L band, this paper reports
a thorough comparison between the performance of a simplified matched Volterra model and the
corresponding (memoryless) narrowband equivalent (with measured AM/AM and AM/PM curves).
The following metrics were considered to perform the comparison:
* Normalized Mean Square Error (NMSE), both in time and frequency domain, between the
simulated HPA output and the result of the measurements after digitization of the
corresponding signal at DUT output.
* Power Spectral Density (PSD) deviation, in particular the spectral regrowth, between the
simulated signal and the DUT output.
The results obtained exhibit a remarkable agreement between the wideband model and the results
measured on the DUT, as well as a remarkable improvement of the performance metrics of the
matched Volterra wideband model as compared to those of the standard narrowband algorithm,
with a manageable additional complexity
Subgroup Analysis According to Human Papillomavirus Status and Tumor Site of a Randomized Phase II Trial Comparing Cetuximab and Cisplatin Combined With Radiation Therapy for Locally Advanced Head and Neck Cancer
19nononePurpose We report a subgroup analysis primarily focused on human papillomavirus (HPV)-related oropharyngeal cancer (OPC) from the Cetuximab Plus Radiotherapy Versus Cisplatin Plus Radiotherapy in Locally Advanced Head and Neck Cancer (CTXMAB+RT; ClinicalTrials.gov identifier NCT01216020) trial comparing radiation therapy with concomitant cisplatin (CDDP) versus concomitant cetuximab (CTX) as first-line treatment of locally advanced head and neck cancer. Methods and Materials The data from all the patients in the CTXMAB+RT trial were reviewed and separately analyzed in 3 groups: p16-positive OPC, p16-negative OPC, and all other cancer sites. The endpoints of interest were locoregional control (LC), metastasis-free survival, cancer-specific survival (CSS), and overall survival (OS). Severe and fatal infectious complications were also reanalyzed to more thoroughly investigate the association between CTX treatment and potentially life-threatening reactions. Results A total of 33 patients had OPC. The HPV status was available for 30 of the 33 patients. Thus, 3 patients treated with CDDP but with unknown HPV status were excluded from the survival analysis. The small number of patients in each group did not allow for significance to be reached for any of the outcomes analyzed. A trend favored the CDDP arm in the p16-positive group for the 2-year LC and OS/CSS rates (100% vs 72.9% and 100% vs 77.8% for CDDP vs CTX). In this group of patients, the hazard ratio for the treatment arm (CTX vs CDDP) was 4.7 (95% confidence interval [CI] 0.5-40.3) for LC, 3.4 (95% CI 0.4-30.5) for OS, and 2.4 for CSS (95% CI 0.2-23.2). A survival benefit favoring the CDDP arm was not evident in the p16-negative OPC group or for patients with cancer located in other sites. Serious or fatal infectious complications occurred only in the CTX arm. Conclusions In patients with p16-positive OPC in the CTXMAB+RT trial, CTX had lower efficacy than CDDP, with possible implications for treatment selection in this clinical setting.noneBuglione, M; Maddalo, M; Corvò, R; Pirtoli, L; Paiar, F; Lastrucci, L; Stefanacci, M; Belgioia, L; Crociani, M; Vecchio, S; Bonomo, P; Bertocci, S; Borghetti, P; Pasinetti, N; Triggiani, L; Costa, L; Tonoli, S; Grisanti, S; Magrini, Sm.Buglione, M; Maddalo, M; Corvò, R; Pirtoli, Luigi; Paiar, F; Lastrucci, L; Stefanacci, M; Belgioia, L; Crociani, Monica; Vecchio, S; Bonomo, P; Bertocci, S; Borghetti, P; Pasinetti, N; Triggiani, L; Costa, L; Tonoli, S; Grisanti, S; Magrini, S. m
Tumor microenvironment of Burkitt lymphoma: different immune signatures with different clinical behavior
: Burkitt lymphoma (BL) is characterized by tumor microenvironment (TME) in which macrophages represent the main component, determining a distinct histological appearance known as "starry sky" pattern. However, in some instances, BL may exhibit a granulomatous reaction that has been previously linked to a favorable prognosis and spontaneous regression. The aim of our study was to deeply characterize the immune landscape of 7 cases of EBV + BL with granulomatous reaction compared to 8 cases of EBV + BL and 8 EBV- BL, both with typical "starry sky" pattern, by Gene expression profiling performed on the NanoString nCounter platform. Subsequently, the data were validated by multiplex and combined immunostaining. Based on unsupervised clustering of differentially expressed genes, BL samples formed 3 distinct clusters differentially enriched in BL with a diffuse granulomatous reaction (cluster 1), EBV+ BL with typical starry sky pattern (Cluster 2), EBV - BL with typical "starry sky" (cluster 3). We observed variations in the immune response signature among BL with granulomatous reaction and BL with typical "starry sky", both EBV + and EBV -. The TME signature in BL with diffuse granulomatous reaction showed a proinflammatory response, while BLs with "starry sky" were characterized by up-regulation of M2- polarization and pro-tumor response. Moreover, the analysis of additional signatures revealed an up-regulation of Dark zone-signature and epigenetic-signature in BL with typical "starry sky". Tumor associated macrophages (TAM) and epigenetic regulators may be promising targets for additional therapies in BL lymphoma opening novel immunotherapeutic strategies