7,245 research outputs found

    Intramyocardial hemorrhage: An enigma for cardiac MRI?

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    Cardiovascular magnetic resonance (CMR) is a useful noninvasive technique for determining the presence of microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH), frequently occurring in patients after reperfused myocardial infarction (MI). MVO, or the so-called no-reflow phenomenon, is associated with adverse ventricular remodeling and a poor prognosis during follow-up. Similarly, IMH is considered a severe damage after revascularization by percutaneous primary coronary intervention (PPCI) or fibrinolysis, which represents a worse prognosis. However, the pathophysiology of IMH is not fully understood and imaging modalities might help to better understand that phenomenon. While, during the past decade, several studies examined the distribution patterns of late gadolinium enhancement with different CMR sequences, the standardized CMR protocol for assessment of IMH is not yet well established. The aim of this review is to evaluate the available literature on this issue, with particular regard to CMR sequences. New techniques, such as positron emission tomography/magnetic resonance imaging (PET/MRI), could be useful tools to explore molecular mechanisms of the myocardial infarction healing process

    Poultry farming solutions for a sustainable development of marshlands areas of South Iraq

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    ArticleThe Department of Agricultural, Food and Forestry Systems of University of Florence carried out cooperation projects in the South Iraq, funded by Italian Ministry of Foreign Affairs and International Coop eration, focused on the development of rural areas. All the proposed interventions were designed taking into account some key points, such as the development of sustainable farming systems, the protection of the environment, the empowerment of women role. Among the main activities, a particular importance is given to the simple solutions for poultry breeding that represents an important economic resource for many farmers and a source of food for a large segment of the population. Therefore the main aim of t he project was to define new building solutions to apply in the area of marshlands. A mobile poultry shelter was designed and built to meet the demand for meat and eggs from a typical rural family. This shelter was designed to be used for extensive breedin g, with animals free to graze outside during the day. A suitable self - building methodology was applied to obtain results from farmers without specific skills for wood construction thanks to which they learn the appropriate way to build poultry shelters. As conclusion, poultry breeding can be spread in the area of marshlands using the simple self - building structures presented in the study

    A transversal educational proposal for prospective primary teachers: The theme of Time

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    Time is a transversal topic that plays a fundamental role in our every-day experience and represents a natural conceptual bridge between common sense ideas and scientific knowledge. Two classes of Prospective Primary Teachers (PPTs) at the Universities of Udine and Verona were introduced to the theme of Time in a formative intervention organized into a) the discussion of various educational and multidisciplinary approaches aimed to deal with different aspects of Time and b) the exploration/experimentation of various instruments for time measurement. In this work, we study and compare the learning outcomes in terms of planning and implementation of educational projects built by PPTs following two different Rubrics

    On-Off Pumping for Drag Reduction in a Turbulent Channel Flow

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    We show that the energy required by a turbulent flow to displace a given amount of fluid through a straight duct in a given time interval can be reduced by modulating in time the pumping power. The control strategy is hybrid: it is passive, as it requires neither a control system nor control energy, but it manipulates how pumping energy is delivered to the system (as in active techniques) to increase the pumping efficiency. Our control employs a temporally periodic pumping pattern, where a short and intense acceleration (in which the pumping system is on) followed by a longer deceleration (in which the pumping system is off) makes the flow alternately visit a quasi-laminar and a turbulent state. The computational study is for a plane channel flow, and employs direct numerical simulations, which present specific computational challenges, for example the highly varying instantaneous value of the Reynolds number, and the importance of discretisation effects. Particular care is devoted to a meaningful definition of drag reduction in the present context. The ability of the forcing to yield significant savings is demonstrated. Since only a small portion of the parameter space is investigated, the best performance of the control technique remains to be assessed

    Experimental and numerical analyses of a masonry arch under base impulse excitation

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    Considering the long-lasting history of the masonry arch theory, the investigation of its dynamic behavior is a relatively recent issue, which is mostly focused on the analytical formulation of the SDOF four-link rigid block mechanism. With the aim of better understanding the seismic response of vaulted masonry structures, the present study is focused on the performance of a scaled arch assembled by dry-joint 3D printed voussoirs. Due to the susceptibility of rigid bodies to base impulse excitation, the tests accounted for a set of windowed sine impulses that allowed computing a failure curve in the frequency-amplitude domain. In order to track the in-plane motion of selected points, a feature tracking based measuring technique was employed. The results have been compared with a finite element model with voussoirs assumed infinitely rigid and friction interface elements, showing an appreciable match. Eventually, the outcomes of impulse base motion tests available in literature were examined, highlighting the differences in terms of failure mechanisms and seismic capacity.(undefined

    2D Zernike polynomial expansion: finding the protein-protein binding regions

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    We present a method for efficiently and effectively assessing whether and where two proteins can interact with each other to form a complex. This is still largely an open problem, even for those relatively few cases where the 3D structure of both proteins is known. In fact, even if much of the information about the interaction is encoded in the chemical and geometric features of the structures, the set of possible contact patches and of their relative orientations are too large to be computationally affordable in a reasonable time, thus preventing the compilation of reliable interactome. Our method is able to rapidly and quantitatively measure the geometrical shape complementarity between interacting proteins, comparing their molecular iso-electron density surfaces expanding the surface patches in term of 2D Zernike polynomials. We first test the method against the real binding region of a large dataset of known protein complexes, reaching a success rate of 0.72. We then apply the method for the blind recognition of binding sites, identifying the real region of interaction in about 60% of the analyzed cases. Finally, we investigate how the efficiency in finding the right binding region depends on the surface roughness as a function of the expansion order
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