252 research outputs found

    Surgical approach to the cavernous sinus for a trigeminal schwannoma resection: technical note and case report

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    We report a rare case of schwannoma of the lateral wall of the cavernous sinus, an exceedingly rare lesion affecting this anatomical district, and discuss salient aspects of the surgical approach to the cavernous sinus, which are traditionally considered technically challenging due to the high risk of postoperative morbidity and mortality related to the presence of the cranial nerves and internal carotid artery

    Ancient Schwannoma of the Cauda Equina: our experience and review of the literature

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    Ancient schwannomas (AS) are exceedingly rare variant of common schwannomas (CS). Only two cases involving the cauda equina region have been previously reported in literature. AS are typically associated with a higher histological degree of degenerative changes (Antoni B areas). It is of peculiar importance, according to our opinion, to outline that, because of their extremely slow growth (which explains the increase of the degenerative changes in respect to the CS) and their typical soft consistency in respect to their standard counterparts, AS usually imply an even better prognosis

    Ricostruzione dei parametri eruttivi e caratterizzazione della granulometria totale tramite simulazioni numeriche dell’eruzione dell’Etna del 3-5 dicembre 2015

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    Il seguente lavoro di tesi si pone l’obiettivo di caratterizzare la granulometria totale e di ricostruire i parametri eruttivi, tramite l’utilizzo dei modelli numerici FPLUME e Fall3D, delle eruzioni dell’Etna avvenute nelle giornate dal 3 al 5 dicembre 2015. Gli eventi parossistici, che hanno avuto luogo principalmente dal cratere Voragine, hanno generato imponenti colonne eruttive ed i tefra rilasciati in atmosfera sono stati trasportati dal vento fino in Calabria, permettendo così la collezione di dati nelle zone distali. Per prima cosa è stata ricostruita la TGSD attraverso la tassellazione di Voronoi e, una volta parametrizzata con distribuzioni di tipo bi-Weibull e bi-Gauss, è stata data in input ai modelli di cui sopra, insieme ad altri parametri presenti nella letteratura scientifica. Modificando opportunamente i parametri di input e confrontando le simulazioni ottenute e i dati di carico a terra a nostra disposizione, attraverso metodi statistici appropriati, si sono osservati risultati migliori con la parametrizzazione della TGSD tramite distribuzione bi-Weibull. E' stata dunque stimata una massa complessiva eruttata tra i ≈ 7 · 10^9 kg ed i 10^10 kg per un altezza massima della colonna di circa 14 km sul livello del mare. Dalle simulazioni risulta inoltre la presenza, all’interno del dominio computazionale, di concentrazioni di tefra in atmosfera superiori ai 2 mg/m^3 fino a 6 ore dopo la conclusione degli eventi parossistici

    La dinamica delle colate di lava

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    Il seguente lavoro di tesi si pone l’obiettivo di presentare alcuni modelli della dinamica delle colate di lava dovute ad eruzioni effusive. La lava è un sistema multifase ed eterogeneo formato da silicati fusi, con cristalli e bolle di gas in sospensione, il cui comportamento reologico è approssimabile a quello di un fluido Bingham. Il moto della lava sarà studiato durante la discesa su un piano con inclinazione costante, dapprima approssimandola ad un fluido isotermo ed in seguito prendendo in considerazione la perdita di calore per irraggiamento verso l’atmosfera

    Assessing the real benefits of surgery for degenerative lumbar spinal stenosis without instability and spondylolisthesis: a single surgeon experience with a mean 8-year follow-up

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    Background: The degenerative lumbar spinal stenosis is one of the most commonly treated spinal disorders in older adults; despite its increasing frequency, it is not yet clear what the most effective therapy might be. The aim of this study is to investigate the very long term results of a homogenized cohort of patients suffering from lumbar spinal stenosis: the first subset of patients operated on with laminectomy and the second subset of patients was also advised to undergo laminectomy but never operated on. Methods: Patients from both subgroups were advised to undergo surgery, according to the same criteria, in the period between 2000 and 2010 and were re-evaluated in the period between January and December 2016. Results: Comparing the two subsets of patients, both suffering from clinically relevant LSS, the first subset returns a statistically significant clinical improvement at follow-up. The rate of excellent results decreases over years. Iatrogenic spinal instability incidence was found to be 3.8% in the present cohort. Conclusions: Although the improvement of the first postoperative years decreases over time and despite the lack of general consensus, the lack of established shared guidelines and the limitations of this research, the results support the utilisation of surgery for the management of this condition. Level of Evidence: 3

    SHIP2: A ‘‘NEW’’ Insulin Pathway Target for Aging Research

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    Strong evidence suggests that systemic inflammation and central adiposity contribute to and perpetuate metabolic syndrome. All of these alterations predispose individuals to type 2 diabetes mellitus (T2DM), cardiovascular disease, as well as Alzheimer’s disease (AD), all characterized by chronic inflammatory status. On the other hand, extensive abnormalities in insulin and insulin-like growth factor I (IGF-I) and IGF-II signaling mechanisms in brains with AD have been demonstrated, suggesting that AD could be a third form of diabetes. The Src homology domain-containing inositol 5-phosphatase 2 (SHIP2) has an important role in the insulin pathway because its over-expression causes impairment of insulin/IGF-1 signaling. Because some singlenucleotide polymorphisms (SNP) of the gene encoding SHIP2 were significantly associated in T2DM patients with metabolic syndrome and some related conditions, we decided to conduct a case–control study on this gene, analyzing AD and T2DM subjects as cases and young, old, and centenarians as controls. Our results suggest a putative correlation between the the rs144989913 SNP and aging, both successful and unsuccessful, rather than age-related diseases. Because this SNP is an insertion/deletion of 28 bp, it might cause an alteration in SHIP2 expression. It is noteworthy that SHIP2 has been demonstrated to be a potent negative regulator of insulin signaling and insulin sensitivity. Many studies demonstrated the association of the insulin/IGF1 pathway with aging and longevity, so it is tempting to speculate that the found association with SHIP2 and aging might depend on its effect on the insulin/IGF-1 pathwa

    Automated segmentation of colorectal tumor in 3D MRI Using 3D multiscale densely connected convolutional neural network

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    The main goal of this work is to automatically segment colorectal tumors in 3D T2-weighted (T2w) MRI with reasonable accuracy. For such a purpose, a novel deep learning-based algorithm suited for volumetric colorectal tumor segmentation is proposed. The proposed CNN architecture, based on densely connected neural network, contains multiscale dense interconnectivity between layers of fine and coarse scales, thus leveraging multiscale contextual information in the network to get better flow of information throughout the network. Additionally, the 3D level-set algorithm was incorporated as a postprocessing task to refine contours of the network predicted segmentation. The method was assessed on T2-weighted 3D MRI of 43 patients diagnosed with locally advanced colorectal tumor (cT3/T4). Cross validation was performed in 100 rounds by partitioning the dataset into 30 volumes for training and 13 for testing. Three performance metrics were computed to assess the similarity between predicted segmentation and the ground truth (i.e., manual segmentation by an expert radiologist/oncologist), including Dice similarity coefficient (DSC), recall rate (RR), and average surface distance (ASD). The above performance metrics were computed in terms of mean and standard deviation (mean ± standard deviation). The DSC, RR, and ASD were 0.8406 ± 0.0191, 0.8513 ± 0.0201, and 2.6407 ± 2.7975 before postprocessing, and these performance metrics became 0.8585 ± 0.0184, 0.8719 ± 0.0195, and 2.5401 ± 2.402 after postprocessing, respectively. We compared our proposed method to other existing volumetric medical image segmentation baseline methods (particularly 3D U-net and DenseVoxNet) in our segmentation tasks. The experimental results reveal that the proposed method has achieved better performance in colorectal tumor segmentation in volumetric MRI than the other baseline techniques

    Radiomics and Magnetic Resonance Imaging of Rectal Cancer: From Engineering to Clinical Practice

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    While cross-sectional imaging has seen continuous progress and plays an undiscussedpivotal role in the diagnostic management and treatment planning of patients with rectal cancer, alargely unmet need remains for improved staging accuracy, assessment of treatment response andprediction of individual patient outcome. Moreover, the increasing availability of target therapies hascalled for developing reliable diagnostic tools for identifying potential responders and optimizingoverall treatment strategy on a personalized basis. Radiomics has emerged as a promising, still fullyevolving research topic, which could harness the power of modern computer technology to generatequantitative information from imaging datasets based on advanced data-driven biomathematicalmodels, potentially providing an added value to conventional imaging for improved patient manage-ment. The present study aimed to illustrate the contribution that current radiomics methods appliedto magnetic resonance imaging can offer to managing patients with rectal cancer

    Centenarians, semi and supercentenarians, COVID-19 and Spanish flu: a serological assessment to gain insight into the resilience of older centenarians to COVID-19

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    Background: Although it is well known that the older people have been the most susceptible to COVID-19, there are conflicting data on the susceptibility of centenarians. Two epidemiological study have shown that older centenarians (> 101 years old at the time of the 2020 pandemic peak) are more resilient than the remaining centenarians, suggesting that this resilience might be linked to the 1918 Spanish Flu pandemic. To gain insight into this matter, specifically whether the resilience of older centenarians to SARS-CoV-2 infection is linked to the Spanish Flu they had been affected by, we conducted a retrospective serological study. This study examined serum samples from 33 centenarians, encompassing semi- (aged > 104 109 years, N = 4), born between 1905 and 1922, against both SARS-CoV-2 and 1918 H1N1 pseudotype virus. Results: Anamnestic and laboratory data suggest that SARS-CoV-2 infection occurred in 8 centenarians. The infection appeared to have been asymptomatic or mild, and hospitalization was not required, despite 3 out of 8 being between 109 and 110 years old. The levels of anti-spike antibodies in centenarians infected and/or vaccinated were higher, although not significantly, than those produced by a random sample of seventy-year-old individuals used as controls. All centenarians had antibody levels against the 1918 H1N1 virus significantly higher (almost 50 times) than those observed in the quoted group of seventy-year-old subjects, confirming the key role in maintaining immunological memory from a priming that occurred over 100 years ago. Centenarians whose blood was collected prior to the pandemic outbreak demonstrated neutralising antibodies against the 1918 H1N1 virus, but all these subjects tested negative for SARS-CoV-2. Conclusion: This retrospective study shows that older centenarians are quite resilient to COVID-19, as they are capable of producing good levels of neutralising antibodies and experiencing mild or asymptomatic disease. This could be attributed to the 1918 Spanish flu pandemic through mechanisms other than the presence of cross-reactive antibodies between the 1918 H1N1 virus and SARS-CoV-2. Another possibility is that the association is purely temporal, solely correlated with the advanced age of resilient centenarians compared to those born after 1918, since older centenarians are known to have better control of immune-inflammatory responses

    Il falso dilemma pubblico-privato. L’anomalia della scuola italiana nel contesto europeo

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    Il modello organizzativo del sistema scolastico italiano in prospettiva storica e comparata nel contesto europeo; prospettive per un adeguamento della scuola italiana al “sistema medio europeo”.- Indice #4- Introduzione, Marcello Pacini #8- Nota metodologica #14- Cap.I Il modello organizzativo del sistema scolastico italiano #18- Cap.II Il sistema medio europeo. Sistemi e problemi di un'analisi comparata #54- Cap.III Verso la deburocratizzazione. Prospettive per un adeguamento della scuola italiana al “sistema medio europeo” #114- Allegato I La struttura del sistema scolastico italiano #146- Relazioni e interventi di discussione sulla ricerca #206- Intervento On. Francesco Casati, Presidente della Commissione Istruzione e Belle Arti della Camera dei Deputati #208- Intervento Sen. Luigi Covatta, Sottosegretario di Stato alla Pubblica Istruzione #212- Intervento Sen. Salvatore Valitutti, Presidente della Commissione Istruzione Pubblica e Belle Arti del Senato della Repubblica #215- Intervento Emanuele Caruso, Dirigente Generale dell'Istruzione Tecnica, Ministero della Pubblica Istruzione #219- Intervento Mario Dupuis, Responsabile Scuola del Movimento Popolare #222- Intervento On. Laura Fincato, Vicepresidente della Commissione Istruzione e Belle Arti della Camera dei Deputati #225- Intervento Aureliana Alberici, Responsabile Scuola/Università della Direzione del P.C.I. #229- Intervento Paolo Serreri, Federazione Scuola Università C.G.I.L. #237- Intervento Daniela Silvestri, Rappresentante nazionale del Sindacato Nazionale Autonomo Lavoratori Scuola SNALS #242- Intervento Paolo Martelli, Direttore di POLITEIA - Centro per la ricerca e la formazione in politica ed etica #245- Intervento Salvatore Sechi, Professore ordinario di Storia Contemporanea, Università di Bologna #252- Intervento Piero Romei, Ricercatore dell'ISGO #257- Intervento Giovanni Bechelloni, Professore ordinario di Sociologia dei processi culturali, Università di Firenze #263- Intervento Giorgio Allulli, Censis #266- Intervento Graziella Morselli, FNISM #270- Intervento Luigi Pedrazzi, Il Mulino #274- Intervento Luciano Benadusi, Responsabile Settore Università e ricerca scientifica della Direzione Socialista #277- Intervento Mario Caronna #Coordinatore scientifico del Centro Studi di Milano #282- Intervento Adriana Rosas, Ricercatore presso il CLAS #287- Intervento Giovanni Tesoro, Ricercatore presso l’ISGO #290- Considerazioni conclusive Luisa Ribolzi, CLAS #29
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