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Glioblastoma is the most aggressive brain tumor and, even with the current multimodal therapy, is an invariably lethal cancer with a life expectancy that depends on the tumor subtype but, even in the most favorable cases, rarely exceeds 2 years. Epigenetic factors play an important role in gliomagenesis, are strong predictors of outcome, and are important determinants for the resistance to radio- and chemotherapy. The latest addition to the epigenetic machinery is the noncoding RNA (ncRNA), that is, RNA molecules that are not translated into a protein and that exert their function by base pairing with other nucleic acids in a reversible and nonmutational mode. MicroRNAs (miRNA) are a class of ncRNA of about 22 bp that regulate gene expression by binding to complementary sequences in the mRNA and silence its translation into proteins. MicroRNAs reversibly regulate transcription through nonmutational mechanisms; accordingly, they can be considered as epigenetic effectors. In this review, we will discuss the role of miRNA in glioma focusing on their role in drug resistance and on their potential applications in the therapy of this tumor.

Shape recognition of geometric models described by triangular meshes is affected by some problems which made it difficult to be performed without errors. Some factors, such as the location errors of points due to acquisition process and the coarse representation of continuous surfaces due to triangular approximation, introduce uncertainty in the recognition process of the geometric shape. This paper introduces some original fuzzy sets suited to recognize geometric form. The membership functions of the fuzzy sets are dynamically defined so that they can be adapted to take into account those properties of the geometric model that affect the uncertainty of the recognition process. The proposed approach is intrinsically very robust and achieves good results also in recognising form features in geometric models affected by point location errors.

Purpose: The aim of this work is the development of a procedure able to model the highly irregular cellular structure of metallic foams on the basis of information obtained by X-ray tomographic analysis. Method: The geometric modelling is based on the feature “pore” characterized by an ellipsoidal shape. The data for the geometric parameters of the instances are obtained with a methodology which is driven by the pore volume distribution curve. This curve shows how much the cells, whose diameter belongs to a given dimensional range, contribute to the reduction of the total volume. Result. The presented methodology has been implemented into a CAD tool consisting of a Matlab routine identifying the instances of the feature “pore” and a CATIA’s macro modelling the closed cells foam. Discussion & Conclusion: The CAD model developed for two types of closed cells foams approximates by considerable accuracy both the density and the volume distribution of the real foams.

Purpose: For some years now, our research group has been developing a new methodology for automatic tolerance inspection starting from an acquired high-density 3D model. In this paper, with a view to grouping together all the information recognisable in a scanned object, a new data structure, called Recognised Geometric Model (RGM), is proposed. Based on this data structure the evaluation of the non-idealities of the acquired object (form, orientation and location non-idealities) can be automatically carried out. Method: RGM is the result of an approach founded on the concepts of non-ideal feature and intrinsic nominal reference. The object to be inspected is segmented into a set of non-ideal features and, for each of them, one or more intrinsic nominal references are identified. An Intrinsic Nominal Reference is detected when a geometric property was recognised to be common to a set of adjacent points in the 3D data set representing the acquired object. The recognition of these references from a scanned object is carried out based on some rules which, therefore, play a leading role in the definition of the domain of the representable entities within RGM. Result: New and old categories of form non-idealities are here defined and some procedures are proposed for a more robust process of verification of traditional tolerance categories (such as the straightness of a cylinder generatrix). Discussion & Conclusion: When using the RGM, tolerances can be specified according to the set of available and recognisable intrinsic nominal references. This allows the automatic geometric inspection of the workpiece. However, the approach here proposed does not rule out the possibility of querying the RGM data structure by explicit geometric product specifications, in order to gather some quantitative information concerning special intrinsic geometric parameters and/or non-idealities.

Purpose: In this paper, an associative-parametric approach is proposed in order to model the mesh of an aeronautical concept starting from a set of high-level structural primitives. To assure orders of continuity higher than C0 between adjacent instances, a suitable mathematical description of the structural primitives has been identified. The maintenance of the continuity constraints must be assured when the mesh is modified. Method: The Bézier curve and the Coons surface patch, with a suitable degree, are used in order to assure orders of continuity higher than C0 in the connection points or edges. Appropriate schemes of dependences are identified to assure the automatic propagation of the modifications complying with the continuity constraints. Result: The approach here proposed allows the designer to carry out the geometric modelling and the automatic mesh generation within one software environment in a fast and interactive way and complying with the geometric continuity constraints and the one-to-one correspondence between the mesh elements. This represents evidently a large advantage since the structural optimization process is simplified, with a relevant man-hours saving. A lower number of data transfers between different software is, moreover, involved with less problems related to the data corruption. Finally low conceptual value operations, due to manual correction activity of the model, are eliminated. Discussion & Conclusion: The methodology here proposed allows the automatic propagation of modifications satisfying the geometric continuity constraints and the one-to-one correspondence between the mesh elements. The approach is implemented into a CAD/CAE tool, called MeshFEM and developed using C++ and Matlab languages and the VTK library for the 3D graphic visualization.

This paper aims at developing a suitable analysis of the point cloud, coming from the optic scanning of a real object, allowing to evaluate automatically the errors without using a nominal CAD model or a GPS specification. Really, this possibility is strictly depending on the capability to recognize in a scanned tessellated model some intrinsic nominal references. This paper is particularly devoted to the automatic error evaluation of axial – symmetric surfaces; for this kind of surfaces two types of intrinsic references can be recognized. An original classification of the error categories is proposed and the related methods for the evaluation of these errors are presented. The methodology is applied to some real cases and the related results are critically discussed.

Automating completely the process of geometric errors verification has some problems. The most criti-cal ones are the preventive shape recognition and the lack of an agreement about criteria to be used to associate ideal features to the extracted points from the real surface. In this paper an approach for automatic metrologi-cal inspection of manufactured parts is proposed. Starting from a tessellated model, coming from a scanned workpiece, the methodology carries out automatically the partition of the acquired surface by a shape recognition approach. Then, the ideal featu-res are associated to the corresponding non-ideal fea-tures, based on some criteria that permit to define the minimum zone solution. The proposed methodology stands out for the number and the types of the auto-matically recognized features. Finally, the form errors, related to all the recognized features, are eva-luated. In this paper the procedure has been used to eva-luate some specific form error typologies for several simulated case-studies and real objects. The results deriving from this experimentation are here critically discussed.

The estimation of axis of axial symmetric geometries, and of other surface differential properties is essential for many applications of geometric models defined by triangular meshes. In this work two methods for axis determination, described in literature, are analyzed and compared. For each method several variants have been carried out; these variants differ for the evaluation criteria of some factors, such as the normal estimation at a vertex of the tessellated model. The methods are compared also in the analysis of models that differ each other for size and regularity of the mesh.

On présente une méthode de traitement d'images infrarouges développée pour étudier les effets calorifiques accompagnant la fatigue des métaux. La méthode permet d'estimer séparément les sources thermoélastiques et la puissance mécanique dissipée durant l'essai. Elle est fondée sur une approximation locale du champ de température de surface de l'éprouvette utilisant, un ensemble de fonctions dépendant de l'espace et du temps et tenant compte des propriétés fréquentielles des sources recherchées. On montre, pour deux alliages courants, que l'analyse d'image permet d'étudier la répartition des sources de chaleur au sein de la partie utile de l'éprouvette.

Scopo di questo lavoro è l’ottimizzazione del modello geometrico di un mock-up per paletta di turbina aeronautica su cui è prevista l’esecuzione di una serie di saldature di prova da realizzare con la tecnologia CDW (Capacity Discharge Welding). Una corretta scelta della geometria del provino è infatti fondamentale per l’attendibilità dei risultati delle prove meccaniche e per validare il processo di saldatura anche su componenti aeronautici. Per la modellazione geometrica è stato eseguito il Reverse Engineering di un prototipo di partenza e successivamente è stato utilizzato un software CAD agendo sulle geometrie 3D. Le simulazioni numeriche FEM sul modello hanno consentito di validare la geometria del mock-up, mediante l’analisi del livello e della distribuzione delle tensioni nelle sezioni più critiche.

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The present work aims at the numerical prediction of the performance of a Contra-Rotating Propellers (CRP) system for a Remotely Piloted Aerial Vehicles (RPAV). The CRP system was compared with an equivalent counter-rotating propellers configuration which was set by considering two eccentric propellers which were rotating at the same speed. Each contra-rotating test case was built by varying the pitch angle of blades of the rear propeller, while the front propeller preserved the original reconstructed geometry. Several pitch configurations and angular velocities of the rear propeller was simulated. Comparisons showed an improvement of the propulsive efficiency of the contra-rotating configuration in case of larger pitch angles combined with slower angular velocities of the rear propeller.

The construction of the artificial emissary of Fucino Lake is one of the most ambitious engineering buildings of antiquity. It was the longest tunnel ever made until the 19th century and, due to the depth of the adduction inlet, it required a monumental and complex incile, which, for functionality, cannot be compared to other ancient emissaries. The Roman emissary and its "incile" (Latin name of the inlet structure) were almost completely destroyed in the 19th century, when Fucino Lake was finally dried. Today, only few auxiliary structures such as wells, tunnels, and winzes remain of this ancient work. As evidence of the ancient incile remains a description made by those who also destroyed it and some drawings made by travelers who, on various occasions, visited the site. This paper presents a virtual reconstruction of the Roman incile, obtained both through the philological study of the known documentation, interpreting iconographic sources that represent the last evidence of this structure, and through the survey on the territory. The main purpose is to understand its technical functionalities, the original structures, and its evolution during the time, taking into account the evolution of the Fucino Lake water levels, technological issues, and finally offering its visual reconstruction.

In the last few years the need for methodologies capable of performing an automated geometric inspection has increased. These methodologies often use 3D high-resolution optical digitisers to acquire points from the surface of the object to be inspected. It is expected that, in the near future, geometric inspection will be requiring more and more the use of these instruments. At present geometric inspection is not profiting from all the opportunities attainable by 3D high-resolution optical scanners or from the numerous tools which can be used for processing the point cloud acquired from the inspected product. For some years now, these authors have been working on a new methodology for automatic tolerance inspection working from a 3D model acquired by optical digitisers. In this paper all the information recognisable in a scanned object is organised into a new data structure, called Recognised Geometric Model (RGM). The final aim is to define a representation of the inspected object for the automatic evaluation of the non-idealities pertaining to the form, orientation and location of the non-ideal features of the acquired object. The key concept of the proposed approach is the capability to recognise some intrinsic nominal properties of the acquired model. These properties are assumed as references to evaluate the non-idealities of the inspected object. With this approach the references of geometric inspection are searched for in the inspected object independently of a tolerance specification and of the availability of a 3D nominal representation. The high-level geometric information within RGM depends on the rules used for its identification. The capability to recognise specific categories of nominal references offers the possibility of introducing new tolerances to be specified. The proposed approach has been implemented in original software by means of which a specific test case has been analysed.