511 research outputs found

    Modeling and Characterization of Three Kinds of MEMS Resonators Fabricated with a Thick Polysilicon Technology

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    Three different kinds of two-port flexural resonators, with both clamped and free ends, and with nominal resonance frequencies between 5 MHz and 50 MHz, were designed and fabricated. Among them, a novel free-free third-mode resonator, as well as a tunable free-free resonator, designed to maintain a high quality factor despite its tunability, are presented. Because of reduced energy loss in the clamps, higher quality factors are expected from free-free devices. To estimate the resonators performance, the effect of temperature and axial stresses on the resonators is investigated: for the clamped-clamped resonator, a theoretical model is also presented. FEM simulations are performed for the three geometries and the results are discussed

    Granular cell tumor of the trachea as a rare cause of dyspnea in a young woman

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    Tracheal granular cell tumors are rare neurogenic neoplasms characterized by an indolent behavior. We report the case of a young woman affected by this tumor with non-specific clinical presentation. We performed a literature search in order to identify all the cases of tracheal granular cell tumor and to summarize the current state of knowledge about this rare disease

    Equivalent Circuit for RF Flexural Free-Free MEMS Resonators

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    A method to extract a lumped-parameter equivalent circuit for a free-free flexural MEMS resonator, based on the Euler-Bernoulli beam equation and exploiting a modal analysis approach, is presented. The dynamic behaviour predicted by the equivalent circuit is compared with FEM simulations, and the effect of a geometrical mismatch is investigated as well. The resonance frequency and the quality factor are correctly predicted. The method could be used for more complex systems of interconnected beams. The circuit can be used as a quick and intuitive analysis tool for the system-level designer and to allow the simulation of the device in a system-level design environment

    Primary malignant pericardial tumour in Lynch syndrome

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    Background: This case represents the first report of malignant primary cardiac tumour in a patient with Lynch Syndrome associated with MSH2 pathogenic variant. Case presentation: A 57-year-old woman with previous ovarian cystadenocarcinoma was admitted to the emergency room for hematic pericardial effusion. Multimodal diagnostic imaging revealed two solid pericardial vascularized masses. After pericardiectomy, the final histological diagnosis was poorly differentiated pleomorphic sarcomatoid carcinoma. During follow-up she developed an ampulla of Vater adenocarcinoma. Genetic analysis identified an MSH2 pathogenic variant. Conclusion: This case contributes to expand the tumour spectrum of Lynch syndrome, suggesting that MSH2 pathogenic variants cause a more complex multi-tumour cancer syndrome than the classic Lynch Syndrome. In MSH2 variant carriers, symptoms such as dyspnoea and chest discomfort might alert for rare tumours and a focused cardiac evaluation should be considered

    Low-energy Coulomb excitation of 94Zr

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    Recent state-of-the-art Monte Carlo shell-model calculations predict shape coexistence in Zr isotopes. In this context, the 94Zr nucleus is particularly interesting since some experimental investigations have already suggested the possible coexistence of spherical and oblate shapes, however, no definitive conclusion on its deformation has been reported to date. As such, a dedicated experiment to study collectivity and configuration coexistence in 94Zr by means of a low-energy Coulomb excitation was performed. This study was performed at the INFN Legnaro National Laboratory with the GALILEO-SPIDER setup, which, in this instance, was further augmented with 6 Lanthanum Bromide scintillators (LaBr3:Ce) in order to to maximize the γ-ray detection efficiency

    Transition probabilities in the X(5) candidate 122^{122}Ba

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    To investigate the possible X(5) character of 122Ba, suggested by the ground state band energy pattern, the lifetimes of the lowest yrast states of 122Ba have been measured, via the Recoil Distance Doppler-Shift method. The relevant levels have been populated by using the 108Cd(16O,2n)122Ba and the 112Sn(13C,3n)122Ba reactions. The B(E2) values deduced in the present work are compared to the predictions of the X(5) model and to calculations performed in the framework of the IBA-1 and IBA-2 models

    Imatinib dose escalation versus sunitinib as a second line treatment in KIT exon 11 mutated GIST: A retrospective analysis

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    none14noWe retrospectively reviewed data from 123 patients (KIT exon 11 mutated) who received sunitinib or dose-escalated imatinib as second line. All patients progressed on imatinib (400 mg/die) and received a second line treatment with imatinib (800 mg/die) or sunitinib (50 mg/die 4 weeks on/2 offor 37.5 mg/day). Deletion versus other KIT 11 mutation was recorded, correlated with clinical benefits. 64% received imatinib, 36% sunitinib. KIT exon 11 mutation was available in 94 patients. With a median follow-up of 61 months, median time to progression (TTP) in patients receiving sunitinib and imatinib was 10 (95% CI 9.7-10.9) and 5 months (95% CI 3.6-6.7) respectively (P = 0.012). No difference was found in overall survival (OS) (P = 0.883). In imatinib arm, KIT exon 11 deletions was associated with a shorter TTP (7 vs 17 months; P = 0.02), with a trend in OS (54 vs 71 months P = 0.063). No difference was found in patients treated with sunitinib (P = 0.370). A second line with sunitinib was associated with an improved TTP in KIT exon 11 mutated patients progressing on imatinib 400 mg/die. Deletions in exon 11 seemed to be correlated with worse outcome in patients receiving imatinib-based second line.openVincenzi B.; Nannini M.; Fumagalli E.; Bronte G.; Frezza A.M.; De Lisi D.; Ceruso M.S.; Santini D.; Badalamenti G.; Pantaleo M.A.; Russo A.; Dei Tos A.P.; Casali P.; Tonini G.Vincenzi, B.; Nannini, M.; Fumagalli, E.; Bronte, G.; Frezza, A. M.; De Lisi, D.; Ceruso, M. S.; Santini, D.; Badalamenti, G.; Pantaleo, M. A.; Russo, A.; Dei Tos, A. P.; Casali, P.; Tonini, G

    Gene expression landscape of sdh-deficient gastrointestinal stromal tumors

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    Background: About 20–40% of gastrointestinal stromal tumors (GISTs) lacking KIT/PDGFRA mutations show defects in succinate dehydrogenase (SDH) complex. This study uncovers the gene expression profile (GEP) of SDH-deficient GIST in order to identify new signaling pathways or molecular events actionable for a tailored therapy. Methods: We analyzed 36 GIST tumor samples, either from formalin-fixed, paraf-fin-embedded by microarray or from fresh frozen tissue by RNA-seq, retrospectively collected among KIT-mutant and SDH-deficient GISTs. Pathway analysis was performed to highlight enriched and depleted transcriptional signatures. Tumor microenvironment and immune profile were also evaluated. Results: SDH-deficient GISTs showed a distinct GEP with respect to KIT-mutant GISTs. In particular, SDH-deficient GISTs were characterized by an increased expression of neural markers and by the activation of fibroblast growth factor receptor signaling and several biological pathways related to invasion and tumor progression. Among them, hypoxia and epithelial-to-mesenchymal transition emerged as features shared with SDH-deficient pheochromocytoma/paraganglioma. In addition, the study of immune landscape revealed the depletion of tumor microenvironment and inflammation gene signatures. Conclusions: This study provides an update of GEP in SDH-deficient GISTs, highlighting differences and similarities compared to KIT-mutant GISTs and to other neoplasm carrying the SDH loss of function. Our findings add a piece of knowledge in SDH-deficient GISTs, shedding light on their putative histology and on the dysregulated biological processes as targets of new therapeutic strategies
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