Simulazione FEM della dinamica di un rotore con smorzatori radiali controllabili

La presente tesi propone una trattazione simulata tramite F.E.M. di un particolare rotore e dei suoi comportamenti in presenza di smorzatori radiali controllabili. Sfruttando il software ANSYS v.11, il rotore, formato da un albero con due dischi calettati, è stato rappresentato tramite elementi PIPE16; ne sono state calcolate le frequenze proprie tenendo in considerazione gli effetti giroscopici. Successivamente sono stati inseriti due smorzatori usando gli elementi COMBIN14 e se ne sono riscontrati gli effetti sulla dinamica tramite analisi Armoniche. Infine, usando alcune “funzioni caratteristiche” è stata simulata la controllabilità degli smorzatori al fine di minimizzare le vibrazioni

Skin Surface Reconstruction and 3D Vessels Segmentation in Speckle Variance Optical Coherence Tomography

In this paper we present a method for in vivo surface reconstruction and 3D vessels segmentation from Speckle-Variance Optical Coherence Tomography imaging, applied to dermatology. This novel technology allows to capture motion underneath the skin surface revealing the presence of blood vessels. Standard OCT visualization techniques are inappropriate for this new source of information, that is crucial in early skin cancer diagnosis. We investigate 3D reconstruction techniques for better visualization of both the external and internal structure of skin lesions, as a tool to help clinicians in the task of qualitative tumor evaluation

The extension problem for partial Boolean structures in Quantum Mechanics

Alternative partial Boolean structures, implicit in the discussion of classical representability of sets of quantum mechanical predictions, are characterized, with definite general conclusions on the equivalence of the approaches going back to Bell and Kochen-Specker. An algebraic approach is presented, allowing for a discussion of partial classical extension, amounting to reduction of the number of contexts, classical representability arising as a special case. As a result, known techniques are generalized and some of the associated computational difficulties overcome. The implications on the discussion of Boole-Bell inequalities are indicated.Comment: A number of misprints have been corrected and some terminology changed in order to avoid possible ambiguitie

Toward a bioethical issue: induced multiple pregnancies and neonatal outcomes

Assisted reproductive technology has made great progress during the last three decades. After the initial enthusiasm, many ethical, legal and social issues related to the application of these procedures began to evolve. Multifetal pregnancy and fetal reduction, embryo cryopreservation, preimplantation genetic diagnosis, risks of birth defects and other adverse outcome associated with assisted reproductive technology are issues that have to be addressed building future collaborative studies and continuing the debate on related ethical issues

An Unusual Treatment of Atrial Fibrillation Percutaneous Exclusion of a Large Coronary Aneurysm

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Supporting Skin Lesion Diagnosis with Content-Based Image Retrieval

In recent years, many attempts have been dedicated to the creation of automated devices that could assist both expert and beginner dermatologists towards fast and early diagnosis of skin lesions. Tasks such as skin lesion classification and segmentation have been extensively addressed with deep learning algorithms, which in some cases reach a diagnostic accuracy comparable to that of expert physicians. However, the general lack of interpretability and reliability severely hinders the ability of those approaches to actually support dermatologists in the diagnosis process. In this paper a novel skin image retrieval system is presented, which exploits features extracted by Convolutional Neural Networks to gather similar images from a publicly available dataset, in order to assist the diagnosis process of both expert and novice practitioners. In the proposed framework, ResNet-50 is initially trained for the classification of dermoscopic images; then, the feature extraction part is isolated, and an embedding network is built on top of it. The embedding learns an alternative representation, which allows to check image similarity by means of a distance measure. Experimental results reveal that the proposed method is able to select meaningful images, which can effectively boost the classification accuracy of human dermatologists

An evaluation of morphological and functional multi-parametric MRI sequences in classifying non-muscle and muscle invasive bladder cancer

Objectives: Our goal is to determine the ability of multi-parametric magnetic resonance imaging (mpMRI) to differentiate muscle invasive bladder cancer (MIBC) from non-muscle invasive bladder cancer (NMIBC). Methods: Patients underwent mpMRI before tumour resection. Four MRI sets, i.e. T2-weighted (T2W) + perfusion-weighted imaging (PWI), T2W plus diffusion-weighted imaging (DWI), T2W + DWI + PWI, and T2W + DWI + PWI + dif-fusion tensor imaging (DTI) were interpreted qualitatively by two radiologists, blinded to histology results. PWI, DWI and DTI were also analysed quantitatively. Accuracy was determined using histopathology as the reference standard. Results: A total of 82 tumours were analysed. Ninety-six percent of T1-labeled tumours by the T2W + DWI + PWI image set were confirmed to be NMIBC at histopathology. Overall accuracy of the complete mpMRI protocol was 94% in differentiating NMIBC from MIBC. PWI, DWI and DTI quantitative parameters were shown to be significantly different in cancerous versus non-cancerous areas within the bladder wall in T2-labelled lesions. Conclusions: MpMRI with DWI and DTI appears a reliable staging tool for bladder cancer. If our data are validated, then mpMRI could precede cystoscopic resection to allow a faster recognition of MIBC and accelerated treatment pathways. Key Points: • A critical step in BCa staging is to differentiate NMIBC from MIBC. • Morphological and functional sequences are reliable techniques in differentiating NMIBC from MIBC. • Diffusion tensor imaging could be an additional tool in BCa staging

Cardiac adaptation to hypertension in adult female Dahl salt-sensitive rats is dependent on ovarian function, but loss of ovarian function does not predict early maladaptation

Aim of study was to examine experimentally the adult female hypertensive heart in order to determine the role of ovary function in the response of the heart to salt-dependent hypertension. Dahl salt-sensitive rats, age 12 weeks, with/without ovariectomy were fed a standard (0.3% NaCl) or high-salt diet (8%) for 16 weeks. Mean arterial blood pressure monitored noninvasively in conscious state increased significantly by high salt. Echocardiography was performed at baseline and endpoint. Heart function and molecular changes were evaluated at endpoint by left ventricle catheterization, by sirius red staining for collagen and by gene expression using quantitative RT-PCR for selected genes. At endpoint, significant concentric hypertrophy was present with high salt. Increase in relative wall thickening with high salt compared to normal diet was more pronounced with intact ovaries (0.33 0.02 and 0.57 0.04 vs. 0.29 0.00 and 0.46 0.03) as was the reduction in midwall fractional shortening (20 0.6 and 14 2 vs. 19 0.9 and 18 1). Ovariectomy increased stroke volume and decreased the ratio of mitral peak velocity of early filling (E) to early diastolic mitral annular velocity (E0 ) (E/E’ ratio) when compared to hearts from intact rats. High salt increased expression of collagen I and III genes and perivascular collagen in the heart slightly, but % interstitial collagen by sirius red staining remained unchanged in intact rats and decreased significantly by ovariectomy. Added volume load but not deterioration of function or structure characterized the nonfailing hypertensive heart of salt-sensitive females ovariectomized at mature age when compared to corresponding intact females

Survey on arterial hypertension management: a report from the ESC Council for Cardiology Practice and the ESC Council on Hypertension

Aims: To explore the management of hypertensive patients by general cardiologists a few months after the European Society of Cardiology (ESC)-European Society of Hypertension (ESH) Guidelines publication. Methods and results: A survey based on a 26-point questionnaire was sent to ∼69 000 worldwide ESC members, a few months after the ESC-ESH Guidelines publication. A total of 1458 responses were collected via a web-based form. Among them, 68% were men, 48% were below 45 years old, and 60% were from Europe. Current guidelines have been read, at least partially, by 92.8%. Measurement of blood pressure (BP) is mostly done using the auscultatory method (58.8%) while unattended BP is rarely performed. Different bladder cuffs are not available for different arm circumferences for 27% of responders. Routine workup in hypertensive patients includes more often 12 leads ECG (97.7%) and echocardiography (79.6%). Only 30.9% of responders systematically assess the cardiovascular risk by the SCORE system and orthostatic hypotension is systematically researched by only 39.1%. Respondents consider that BP target of 140/90 mmHg is achievable in 60-80% of patients and 130/80 mmHg in 40-60%. Guidelines are considered too tight to be achievable by 15.6%, while 77.4% consider they are exactly right. Low patient's compliance, awareness of hypertension (HT) risk, and, at a lower degree, physician inertia, represent the main treatment challenges in reaching BP goals to most respondents, while treatment effectiveness is not in question. The present survey demonstrates specific gaps in HT management that need attention in clinical practice