1,721,102 research outputs found
Early diagnosis of pancreatic cancer: What strategies to avoid a foretold catastrophe
Full text linkWhile great strides in improving survival rates have been made for most cancers in recent years, pancreatic ductal adenocarcinoma (PDAC) remains one of the solid tumors with the worst prognosis. PDAC mortality often overlaps with incidence. Surgical resection is the only potentially curative treatment, but it can be performed in a very limited number of cases. In order to improve the prognosis of PDAC, there are ideally two possible ways: the discovery of new strategies or drugs that will make it possible to treat the tumor more successfully or an earlier diagnosis that will allow patients to be operated on at a less advanced stage. The aim of this review was to summarize all the possible strategies available today for the early diagnosis of PDAC and the paths that research needs to take to make this goal ever closer. All the most recent studies on risk factors and screening modalities, new laboratory tests including liquid biopsy, new imaging methods and possible applications of artificial intelligence and machine learning were reviewed and commented on. Unfortunately, in 2022 the results for this type of cancer still remain discouraging, while a catastrophic increase in cases is expected in the coming years. The article was also written with the aim of highlighting the urgency of devoting more attention and resources to this pathology in order to reach a solution that seems more and more unreachable every day
Pancreatic cancer in 2021: What you need to know to win
No full textPancreatic cancer is one of the solid tumors with the worst prognosis. Five-year survival rate is less than 10%. Surgical resection is the only potentially curative treatment, but the tumor is often diagnosed at an advanced stage of the disease and surgery could be performed in a very limited number of patients. Moreover, surgery is still associated with high post-operative morbidity, while other therapies still offer very disappointing results. This article reviews every aspect of pancreatic cancer, focusing on the elements that can improve prognosis. It was written with the aim of describing everything you need to know in 2021 in order to face this difficult challenge
Caratteristiche geometriche delle immagini EROS. Esempio di estrazione di un DSM
Full text linkTra i sistemi satellitari ad alta risoluzione riveste particolare interesse il sensore presente a bordo del primo, ed attualmente unico, satellite della costellazione EROS. Esso è caratterizzato da una risoluzione geometrica al nadir di 1.8 m, che diventa 2.4 m circa nelle acquisizioni non nadirali. Tali valori sono inferiori a quelli delle immagini fornite da altri sensori ad alta risoluzione (ad esempio Ikonos e QuickBird), ma è prevista la modalità di acquisizione asincrona con prese stereoscopiche eseguite lungo lo stesso segmento di orbita o durante passaggi successivi. Il lavoro analizza le principali proprietà geometriche e radiometriche delle immagini EROS ed affronta il problema dell’estrazione di un modello digitale della superficie fornendo una prima valutazione dell’accuratezza del prodotto ottenuto
Quantitative determination of crystalline and amorphous phase in traditional ceramics by combined Rietveld-RIR method
No full textA mixture composed of quartz, clay minerals, and feldspars was heated at different temperatures in the range 1085-1215 degrees C for the production of traditional single firing white paste ceramics. The products display different physical and mechanical properties as a function of temperature. The variation of the physical properties such as the linear shrinkage,the water absorption, and others is directly related to changes in the phase composition and their microstructure, The quantitative determination of both crystalline (mullite, quartz, corundum, zircon, and albite) and amorphous phase (mainly alkali-aluminosilicatic glass), and the determination of some microstructural features of the phases have been calculated using the combined Rietveld-RIR method, a powerful X-Ray powder diffraction full profile fitting technique which was succesfully employed in a variety of applications (quantitative determination of asbestos in bulk materials, quantitative determination of the zeolite fraction and glass in pyroclastic tuffs, and others)
reazioni cutanee avverse da farmaci inibitori del fattore di crescita epidermico (EGFR-Is) della Clinica Dermatologica dell' Università di Parma
No full textOrthorectification of HR satellite images with space-derived DSM
No full textThe paper addresses the item of orthorectification of high resolution satellite images and the assessment of the final accuracy achieved when Digital Surface Models (DSM) provided by other remotely sensed data are used. By using a photogrammetric processing, a DSM was obtained from an EROS (Earth Resources Observation System) high resolution stereo pair acquired over a portion of the city of Bologna (Italy). After the accuracy assessment of the terrain model trough the comparison with external Digital Elevation Model (DEM), a broad range of orthorectification procedures with high resolution satellite images (Ikonos, QuickBird and EROS) have been therefore investigated by the authors. The accuracy in final positioning provided by the orthorectification of a QuickBird imagery with the EROS-derived elevation dataset was evaluated using a evenly spaced set of Ground Control Points from GPS survey. The achieved accuracy could meet the requirements needed in technical cartography specifications (to scale as large as 1:10000) updating of well recognizable features or entities and generic mapping procedures
Esperienze Laser Scanner terrestre nell’ambito della conservazione dei beni culturali e archeologici.
No full textDevelopment and validation of a probabilistic model for notch fatigue strength prediction of tool steels based on surface defects
Full text linkA new model for the high cycle notch fatigue strength prediction of tool steels subjected to axial loading is proposed, based on previous literatures studies and experimental tests carried out on six different tool steels, including rotating bending fatigue tests on notched specimens, fractographic analyses, hardness, residual stress, and roughness measurements. The novelty is the assumption that surface defects are the main cause of notch fatigue failures of such steels. A probabilistic approach was implemented by modeling size distributions of defects, resulting in the prediction of normal distributions of fatigue strength. Like to other previous models, the effect of steel hardness, surface residual stress, notch severity, and specimen size was also taken into account. Model calibration and validation were performed using the data collected by the experimental activity. Model behavior was investigated by performing a sensitivity analysis, aiming to verify the response to variations of the considered input variables. Prediction errors of only 1.3% (on average) and 3.1% (maximum) resulted from the comparison between model-predicted and experimental notch fatigue strength
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