Archivio istituzionale della ricerca - Alma Mater Studiorum Università di Bologna
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Footnotes to the Birational Geometry of Primitive Symplectic Varieties
Full text linkIn this note, we extend to the singular case some results on the birational geometry of irreducible holomorphic symplectic manifolds
Primary Intra-operative Embolisation During Urgent Parallel Graft Endovascular Repair in Paravisceral Symptomatic Aortic Pseudoaneurysm
Full text linkObjective: Paravisceral aortic lesions present significant challenges for endovascular treatment. This retrospective analysis of consecutively treated patients from April 2017 to June 2021 aimed to analyse the outcome of primary intra-operative embolisation of aortic complicated pseudoaneurysms and gutter channels during parallel graft (PG) repair of paravisceral symptomatic aortic pseudoaneurysms.
Methods: Patients with symptomatic pseudoaneurysms of the paravisceral aorta treated with PGs using chimney or periscope configurations were included. Thoracic endografts were positioned to exclude the aortic lesions. Coil embolisation of both the lesions and gutter channels was performed after graft deployment and prior to ballooning of the stent grafts. The primary endpoints were technical success (defined as exclusion of the pseudoaneurysm, target visceral vessel [TVV] patency, absence of gutter endoleaks) and clinical success (technical success + resolution of symptoms + absence of major adverse events) at 30 days. Secondary endpoints included overall survival, TVV patency, gutter endoleaks, and freedom from re-interventions during follow up.
Results: Six patients (four women) were treated for pseudoaneurysm rupture (three cases) and symptomatic aortic pseudoaneurysm (three cases) of the paravisceral aorta. The patients' anatomies were unsuitable for off the shelf devices and patients were all deemed to be at prohibitive surgical risk. A total of 15 TVVs were revascularised (comprising three coeliac arteries, five superior mesenteric arteries, and seven renal arteries) using 10 chimney and five periscope PGs. One coeliac artery was occluded. Seventy coils were deployed to embolise both the aortic ruptures and gutter channels. Both technical and clinical success rates were 100%. The median follow up was 17 months (IQR 5, 35), during which time three patients died due to non-aortic related causes. One coeliac artery (6%) was occluded, and no endoleak evidence was found.
Conclusion: Primary intra-operative embolisation during parallel graft endovascular repair of paravisceral symptomatic aortic pseudoaneurysms may be both safe and effective in excluding the pseudoaneurysm when other options are unavailable
Modeling of Exhaust Gas Temperature at the Turbine Outlet Using Neural Networks and a Physical Expansion Model
Full text linkThe accurate estimation of exhaust gas temperature across the turbine is always more important for the optimization of engine performance, ensuring durability of the turbine impeller and catalyst, and reducing and calculating emissions concentration. Traditional physical modeling approaches, based on thermodynamic and fluid dynamics features of gas expansion, can be used for this purpose. However, recent advancements in machine learning, particularly neural networks, offer a data-driven alternative that may enhance prediction accuracy and computational efficiency. This study presents a methodology that integrates a semi-physical turbine model for estimating the exhaust gas temperature at the turbine outlet with a neural network-based approach for predicting the pressure at the turbine inlet. The model utilizes the exhaust gas temperature upstream of the turbine, a model for which was developed in a previous work of the authors. The models are calibrated with steady-state data and then evaluated based on accuracy and robustness under transient operating conditions on six driving cycles with different features. In this way, robust and reliable validation of the models is presented, since the testing is performed on various conditions not used for model development and calibration. Results show an average root mean square error of 14%, including the initial portions of driving cycles performed with a cold engine. Thus, the developed approach that includes multiple modeling methods shows a good predictivity, which is the main objective of this research activity
Pan-enteric Capsule Endoscopy to Characterize Crohn's Disease Phenotypes and Predict Clinical Outcomes in Children and Adults: The Bomiro Study
No full textBackground: Pan-enteric capsule endoscopy (PCE) provides useful information for the management of Crohn's disease (CD), especially in children. No study has evaluated the ability of PCE to characterize CD phenotypes and outcomes in children and adults. Methods: In a prospective multicenter observational study, we recruited patients with CD >6 years from 4 centers in Italy. Patients underwent clinical, biomarker assessment and PCE. Lesions were graded using the PCE system. For each segment, the most common lesion (MCL), the most severe lesion (MSL), and the extent of involvement were defined. Disease severity, extent, and clinical outcomes were compared between children and adults. A logistic regression analysis was used to identify predictive factors for negative outcomes in both age groups. Results: One hundred ninety-four consecutive patients (adults/children: 144/50) were evaluated for a total of 249 procedures. Children were more likely to have extensive disease, particularly in the colon. Higher MCL scores were independently associated with treatment escalation (odds ratio [OR], 4.09; 95% CI, 1.80-9.25; P = .001), while >30% disease extent was more indicative of clinical and endoscopic relapse (OR, 2.98; 1.26-7.08; P = .013). Disease extent was the only factor associated with endoscopic recurrence in children (OR, 4.50; 95% CI, 1.47-13.77; P = .008), while severe lesions in adults provided a better predictor of treatment escalation (OR, 4.31; 95% CI, 1.52-12.1; P = .006). Postexamination, PCE contributed to a change of therapy in 196/249 (79%) of the procedures. Conclusions: PCE allowed the characterization of CD phenotypes in children and adults by assessing disease severity and extent, which are of different importance in predicting clinical outcomes in these age groups
Primary and middle school students' views on inclusive physical education: Perceptions, practices, and future directions
Full text linkBackground: Physical Education (PE) classes are vital for nurturing students' social development and promoting collaboration. This study examined how primary and middle school students perceived PE classes, with a focus on collaboration, well-being and enjoyment, teacher behavior, the inclusion of nondisabled and disabled students, and general class behavior. Methods: One-hundred and seventy students (24 primary school and 146 middle school students) were surveyed using a questionnaire. Results: Exploratory Factor Analysis identified seven factors including: well-being, activities for all students, teacher-oriented behavior, collaboration, and attention to students with disabilities. Linear regressions on each identified Factor revealed higher well-being (Factor 1) between primary and middle school students. In addition, the perceived well-being in PE classes and staying together with classmates among younger middle school students was found to be higher than that reported by their older counterparts in middle school. The analysis also revealed that males perceived a higher well-being in PE classes than females. Conclusion: The research underscores that primary and especially middle school PE teachers should promote the well-being of students by creating inclusive and enjoyable PE classes. The PE classes should consider the differences between sexes and the individual differences. Finally, this research lays the foundation for future investigations to refine inclusive PE strategies and improve students' well-being
An asymptotic relationship between Lane-Emden systems and the 1-bilaplacian equation
No full textConsider the following Lane-Emden system with Dirichlet boundary conditions:
in a bounded domain
, for subcritical. We study the asymptotic behavior of
least-energy solutions when , for any fixed which, in
the case , is smaller than . We show that these solutions
converge to least-energy solutions of a semilinear equation involving the
1-bilaplacian operator, establishing a new relationship between these objects.
As a corollary, we deduce the asymptotic behavior of solutions to
-bilaplacian Lane-Emden equations as the power in the nonlinearity goes to
infinity.
For the proof, we rely on the reduction by inversion method and on tools from
nonsmooth analysis, considering an auxiliary nonlinear eigenvalue problem. We
characterize its value in terms of the Green function, and prove a Faber-Krahn
type result. In the case of a ball, we can characterize explicitly the
eigenvalue, as well as the limit profile of least-energy solutions to the
system as
ECG-Gated Cardiac Multidetector CT Evaluation of the Normal Pulmonary Valve and Right Ventricular Outflow Tract in Dogs
No full textWith the advancement in imaging technology, ECG-gated cardiac multidetector computed tomography (MDCT) has emerged as a tool for the anatomic evaluation of the pulmonary valve and right ventricular outflow tract (RVOT) in human medicine. Currently, the evaluation of the pulmonary valve relies primarily on echocardiographic examination. However, the bi-dimensional nature of this technique and the location/orientation of the pulmonary valve in the thoracic cavity can pose challenges. In human medicine, ECG-gated MDCT distinguishes four main anatomic components of the pulmonary valve and RVOT: the pulmonary valve leaflets, the sinotubular junction, the anatomic ventriculo-arterial junction and the hemodynamic ventriculo-arterial junction. Hence, this study aimed to describe the computed tomographic findings of the normal RVOT and pulmonary cusps in a population of dogs.This is an anatomic prospective descriptive study. A total of 24 dogs underwent a complete echocardiographic examination and an ECG-gated MDCT to rule out pulmonary valve abnormalities. Multiplanar reconstruction of the pulmonary valve was obtained. Additionally, hearts from three dogs euthanized for reasons unrelated to the study were collected and their gross and histological findings were compared with the CT images. The ECG-gated MDCT provided good visualization of the pulmonary valve leaflets, the sinotubular junction, the anatomic ventriculo-arterial junction and the hemodynamic ventriculo-arterial junction. Notably, the short-axis view of the pulmonary valve anatomy resembled the 'Mercedes-Benz sign' characteristic of the aortic valve in all dogs. In conclusion, this study provides the first description of the CT anatomy of the RVOT in dogs without pulmonary valve and RVOT abnormalities
Quantitative urine spot microsamples for the chiral analysis of clenbuterol by capillary electrokinetic chromatography
Full text linkThe application of quantitative volumetric dried urine spot (qDUS) sampling and analysis to the enantioselective determination of the β2-adrenergic agonist clenbuterol is described herein for the first time. The chiral determination is obtained by capillary electrokinetic chromatography (CEKC) coupled to tandem mass spectrometry (MS/MS), using carboxymethyl-β-cyclodextrin as the chiral selector and sample stacking by electrokinetic injection. Innovative qDUS was carried out by means of Capitainer®B 50 devices, which were confirmed to be able to produce volumetrically accurate 50-μL urine spots and applying an accelerated drying protocol by dehumidified air. After solvent extraction, the samples were analysed by the CEKC-MS/MS method. The analytical workflow was validated according to current international guidelines, with good results in terms of linearity (r^2 = 0.9994 for both enantiomers), extraction yields (≥ 87 %), intra- and inter-day precision RSD (≤ 11.8 %) and matrix effect (≤ 11 %). Sample stability was high (≥ 97 %) even though qDUS were stored at room temperature for 90 days. Application to the analysis of real qDUS samples from patients undergoing therapy with racemic clenbuterol was successful, with negligible detected enantiomeric excess, as expected. The developed analytical platform based on qDUS coupled to CEKC-MS/MS is thus suitable for application to enantioselective determination of clenbuterol in different settings, including toxicological, forensic and therapeutic drug monitoring ones
Valutare gli apprendimenti nella scuola primaria. Metodologie e materiali per la valutazione in ingresso, in itinere e finale
No full textSi tratta di una vera e propria Guida per gli insegnanti della scuola primaria sui temi della valutazione degli apprendiment
Circolazione cerebrale, meningi encefaliche e liquido cerebrospinale
No full textIn questo capitolo verrà fornita una descrizione delle basi anatomiche e funzionali della circolazione cerebrale. L’organizzazione dell’apporto ematico a questo distretto presenta caratteristiche peculiari rispetto a quelle presenti in altre circolazioni periferiche: in particolare, il sangue arterioso arriva al tessuto cerebrale tramite diversi vasi ematici, che possiedono un’innervazione caratteristica. Quindi, si esamineranno i meccanismi di regolazione della circolazione cerebrale, analizzando anche gli aspetti relativi alla microcircolazione. In particolare, verrà analizzato il ruolo esercitato dalla barriera ematoencefalica nel controllo degli scambi di sostanze tra sangue e tessuto cerebrale. Verranno poi descritte le meningi encefaliche e i meccanismi di produzione, scorrimento e riassorbimento nel circolo ematico del liquido cerebrospinale, che circonda SNC e riempie le sue cavità interne. Da ultimo, si discuteranno le principali tecniche di visualizzazione in vivo dell’attività neuronale basate sul rilievo di variazioni del flusso ematico cerebrale