132 research outputs found

    Human-Mechanical system interaction in Virtual Reality

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    The present work aims to show the great potential of Virtual Reality (VR) technologies in the field of Human-Robot Interaction (HRI). Indeed, it is foreseeable that in not too distant future cooperating robots will be increasingly present in human environments. Many authors actually believe that after the current information revolution, we will witness the so-called "robotics revolution", with the spread of increasingly intelligent and autonomous robots capable of moving into our own environments. Since these machines must be able to interact with human beings in a safe way, new design tools for the study of Human-Robot Interaction (HRI) are needed. The author believes that VR is an ideal design tool for the study of the interaction between humans and automatic machines, since it allows the designers to interact in real-time with virtual robotic systems and to evaluate different control algorithms, without the need of physical prototypes. This also shields the user from any risk related to the physical experimentation. However, VR technologies have also a more immediate application in the field of HRI, such as the study of usability of interfaces for real-time controlled robots. In fact, these robots, such as robots for microsurgery or even "teleoperated" robots working in a hostile environments, are already quite common. VR allows the designers to evaluate the usability of such interfaces by relating their physical input with a virtual output. In particular, the author has developed a new software application aimed at simulating automatic robots and, more generally, mechanical systems in a virtual environment. The user can interact with one or more virtual manipulators and also control them in real-time by means of several input devices. Finally, an innovative approach to the modeling and control of a humanoid robot with high degree of redundancy is discussed. VR implementation of a virtual humanoid is useful for the study of both humanoid robots and human beings

    Genome Composition Plasticity in Marine Organisms

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    The molar ratio of the nucleotides (GC%, i.e. the Guanine+Cytosine content) is well known to evolve through the genomes of all the organisms. Several hypotheses have been drawn out to explain the causes of the nucleotide composition variability among orgnisms. In the Thesis project major attention has been directed to the Metabolic Rate hypothesis (MRh). The main goal was to test if the MRh, first proposed to explain the nucleotide variability within mammalian genomes, could also explain the base composition variability among lower vertebrates and invertebrates. To this aim an extensive analysis of more than two hundred teleostean species has been carried out, followed by a pioneering study of annelid polychaete and tunicate genomes. Regarding teleosts, the results clearly highlighted that environment (i.e. salinity) and lifestyle (i.e. migration) both affect simultaneously the physiology (the metabolic rate), the morphology (the gill area) and the genome composition (GC%). Thus supporting a link between the metabolic rate (MR) and the genome base composition, as expected in the light of the MRh. Moreover, a comparative analysis of completely sequenced teleostean genomes showed that the metabolic rate was correlated not only with the GC content of the genome, but also with the intron structures. Indeed, at increasing metabolic rates introns were shorter and GC-richer. A preliminary analysis of annelids polychaetes showed that motile and sessile species were characterized by different MR and GC%, being both higher in the former than in the latter. The investigation was extended to the well known solitary tunicates, C. robusta and the congeneric C. savignyi. Our data revealed slight but significant morpho-physiological differences between the two species, consistent not only with an ecological niche differentiation, but also with their genomic GC content. All the above results converge towards the same conclusion, thus giving consistency to the MRh as major factor driving the genome base composition evolution of all living organisms

    Heterogeneous design and mechanical analysis of HELIAS 5-B helium-cooled pebble bed breeding blanket concept

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    One of the most challenging objectives of the European research concerning nuclear fusion technology, promoted by the EUROfusion consortium, is to bring stellarator-type nuclear fusion devices to maturity. To this purpose, studies on a large HELIcal-axis advanced stellarator (HELIAS), extrapolated from Wendelstein 7-X and based on a 5-fold symmetry (HELIAS 5-B), are currently ongoing. The HELIAS 5-B stellarator reactor will be endowed with a breeding blanket (BB) system to allow for the self-sustainability of the nuclear fusion reaction and make it suitable for electricity generation. In this paper, we present the first ever heterogeneous mechanical design and the preliminary structural assessment of a bean-shaped ring of a HELIAS 5-B BB sector. The proposed mechanical design, which is based on the helium-cooled pebble bed (HCPB) BB concept and developed according to the “sandwich” architecture, foresees an actively cooled segment box connected to a back-supporting structure equipped with manifolds. The internal region (breeding zone) is reinforced by actively cooled steel plates. The proposed heterogeneous design was checked against nominal loads and an in-box loss of coolant accidental scenario, which is a typical design driver for BBs. The assessment has been performed according to the RCC-MRx structural design code. Our results are herewith presented and critically discussed, focusing on the potential follow-up of the HELIAS 5-B HCPB BB design

    Acquired ptosis associated with oculomotor and contralateral facial nerve synkinesis: the first reported case

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    Evidence of oculomotor nerve (ON) synkinesis is a common occurrence following both acquired and congenital III nerve palsy. It is generally accepted that aberrant regeneration is the likely aetiology of synkinesis in acquired III nerve palsy, following intracranial aneurysm, trauma, compressive neoplasms, cavernous sinus thrombosis and basilar meningitis

    Development of a New Experimental Protocol for Analysing the Race-walking Technique Based on Kinematic and Dynamic Parameters

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    Abstract This paper describes a new motion analysis protocol for race-walking. The protocol has been tested under laboratory conditions on a real athlete of the Italian national race-walking team. The experimental setup included a motion capture system and a force platform to record both kinematic and dynamic aspects of the athletic action. Thus, any infringement of the rules can be detected, based on the measure of knee flexion-extension and the loss of ground contact. The biomechanical efficiency can be determined from the joint angles and the temporal components of gait. The results of experiments show that the protocol can be a valuable tool to assist athletes and trainers in improving race-walking technique

    Anatomically reduced fixation should always be considered when treating B and C proximal epiphyseal humeral fractures

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    Background Proximal humeral fractures are commonly observed in elderly patients. Management of these injuries is controversial. Literature comparing locking plate fixation, arthroplasty, and conservative treatments show no clear advantages for any of these management strategies. Thus far, no study has considered anatomically reduced fractures obtained after locking plate treatment. To clarify the best surgical procedure in middle-aged patients, we considered outcomes and major complications leading to surgical revision following an anatomically reduced fracture fixed with locking plate and reverse shoulder arthroplasty (RSA) in the treatment of type B/C fractures in patients between 50 and 75 years of age. Methods This is a retrospective study including 59 patients between 50 and 75 years of age with type B/C proximal humeral fracture treated with RSA or with locking plate fixation (resulting in an anatomical reduction) between January 2010 and December 2018. Preoperative radiographs and computed tomography (CT) were evaluated in all patients. Clinical and radiologic follow-up was performed using range of motion (ROM), the Constant-Murley Score (CMS), the Oxford Shoulder Score (OSS), the Simple Shoulder Test (SST), the Subjective Shoulder Value (SSV), and visual analog scale (VAS). Major complications were considered. Results In the plate fixation group, ROM, CMS, SST, and VAS were higher than in the RSA group. Lower complication rates compared with the literature were observed in both groups. Anatomically reduced fracture fixed with plate and screw could outperform RSA in terms of outcome. In second-level centers where traumatology is performed by surgeons with great expertise in upper limb trauma, the choice between plate fixation and reverse arthroplasty should be made during surgery. Conclusion Anatomically reduced fractures showed better outcomes compared with RSA in type B/C fractures. Surgeons should always try to perform a reduction of the fracture in order to understand if a plate fixation could be feasible. If it is impossible to perform an anatomical reduction, we suggest to consider RSA. This is a retrospective observational study

    AAV-mediated transcription factor EB (TFEB) gene delivery ameliorates muscle pathology and function in the murine model of Pompe Disease

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    Pompe disease (PD) is a metabolic myopathy due to acid alpha-glucosidase deficiency and characterized by extensive glycogen storage and impaired autophagy. We previously showed that modulation of autophagy and lysosomal exocytosis by overexpression of the transcription factor EB (TFEB) gene was effective in improving muscle pathology in PD mice injected intramuscularly with an AAV-TFEB vector. Here we have evaluated the effects of TFEB systemic delivery on muscle pathology and on functional performance, a primary measure of efficacy in a disorder like PD. We treated 1-month-old PD mice with an AAV2.9-MCK-TFEB vector. An animal cohort was analyzed at 3 months for muscle and heart pathology. A second cohort was followed at different timepoints for functional analysis. In muscles from TFEB-treated mice we observed reduced PAS staining and improved ultrastructure, with reduced number and increased translucency of lysosomes, while total glycogen content remained unchanged. We also observed statistically significant improvements in rotarod performance in treated animals compared to AAV2.9-MCK-eGFP-treated mice at 5 and 8 months. Cardiac echography showed significant reduction in left-ventricular diameters. These results show that TFEB overexpression and modulation of autophagy result in improvements of muscle pathology and of functional performance in the PD murine model, with delayed disease progression

    Length and GC Content Variability of Introns among Teleostean Genomes in the Light of the Metabolic Rate Hypothesis

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    A comparative analysis of five teleostean genomes, namely zebrafish, medaka, three-spine stickleback, fugu and pufferfish was performed with the aim to highlight the nature of the forces driving both length and base composition of introns (i.e., bpi and GCi). An inter-genome approach using orthologous intronic sequences was carried out, analyzing independently both variables in pairwise comparisons. An average length shortening of introns was observed at increasing average GCi values. The result was not affected by masking transposable and repetitive elements harbored in the intronic sequences. The routine metabolic rate (mass specific temperature-corrected using the Boltzmann\u27s factor) was measured for each species. A significant correlation held between average differences of metabolic rate, length and GC content, while environmental temperature of fish habitat was not correlated with bpi and GCi. Analyzing the concomitant effect of both variables, i.e., bpi and GCi, at increasing genomic GC content, a decrease of bpi and an increase of GCi was observed for the significant majority of the intronic sequences (from ~40% to ~90%, in each pairwise comparison). The opposite event, concomitant increase of bpi and decrease of GCi, was counter selected (from <1% to ~10%, in each pairwise comparison). The results further support the hypothesis that the metabolic rate plays a key role in shaping genome architecture and evolution of vertebrate genomes

    Radiomics analysis in gastrointestinal imaging: a narrative review

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    Background and Objective: To present an overview of radiomics radiological applications in major gastrointestinal oncological non-oncologic diseases, such as colorectal cancer, pancreatic cancer, gastro- oesophageal cancer, gastrointestinal stromal tumor (GIST), hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), and non-oncologic diseases, such as liver fibrosis, nonalcoholic steatohepatitis, and inflammatory bowel disease. Methods: A search of PubMed databases was performed for the terms “radiomic”, “radiomics”, “liver”, “small bowel”, “colon”, “GI tract”, and “gastrointestinal imaging” for English articles published between January 2013 and July 2022. A narrative review was undertaken to summarize literature pertaining to application of radiomics in major oncological and non-oncological gastrointestinal diseases. The strengths and limitation of radiomics, as well as advantages and major limitations and providing considerations for future development of radiomics were discussed. Key Content and Findings: Radiomics consists in extracting and analyzing a vast amount of quantitative features from medical datasets, Radiomics refers to the extraction and analysis of large amounts of quantitative features from medical images. The extraction of these data, integrated with clinical data, allows the construction of descriptive and predictive models that can build disease-specific radiomic signatures. Texture analysis has emerged as one of the most important biomarkers able to assess tumor heterogeneity and can provide microscopic image information that cannot be identified with the naked eye by radiologists. Conclusions: Radiomics and texture analysis are currently under active investigation in several institutions worldwide, this approach is being tested in a multitude of anatomical areas and diseases, with the final aim to exploit personalized medicine in diagnosis, treatment planning, and prediction of outcomes. Despite promising initial results, the implementation of radiomics is still hampered by some limitations related to the lack of standardization and validation of image acquisition protocols, feature segmentation, data extraction, processing, and analysi

    Conceptual Design of the Steam Generators for the EU DEMO WCLL Reactor

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    In the framework of the EUROfusion Horizon Europe Programme, ENEA and its linked third parties are in charge of the conceptual design of the steam generators belonging to EU DEMO WCLL Breeding Blanket Primary Heat Transfer Systems (BB PHTSs). In particular, in 2021, design activities and supporting numerical simulations were carried out in order to achieve a feasible and robust preliminary concept design of the Once Through Steam Generators (OTSGs), selected as reference technology for the DEMO Balance of Plant at the end of the Horizon 2020 Programme. The design of these components is very challenging. In fact, the steam generators have to deliver the thermal power removed from the two principal blanket subsystems, i.e., the First Wall (FW) and the Breeding Zone (BZ), to the Power Conversion System (PCS) for its conversion into electricity, operating under plasma pulsed regime and staying in dwell period at a very low power level (decay power). Consequently, the OTSG stability and control represent a key point for these systems' operability and the success of a DEMO BoP configuration with direct coupling between the BB PHTS and the PCS. In this paper, the authors reported and critically discussed the FW and BZ steam generators' thermal-hydraulic and mechanical design, the developed 3D CAD models, as well as the main results of the stability analyses and the control strategy to be adopted
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