25 research outputs found

    Variations on Fibrinogen-Erythrocyte Interactions during Cell Aging

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    Erythrocyte hyperaggregation, a cardiovascular risk factor, is considered to be caused by an increase in plasma adhesion proteins, particularly fibrinogen. We have recently reported a specific binding between fibrinogen and an erythrocyte integrin receptor with a β3 or β3-like subunit. In this study we evaluate the influence of erythrocyte aging on the fibrinogen binding. By atomic force microscopy-based force spectroscopy measurements we found that increasing erythrocyte age, there is a decrease of the binding to fibrinogen by decreasing the frequency of its occurrence but not its force. This observation is reinforced by zeta-potential and fluorescence spectroscopy measurements. We conclude that upon erythrocyte aging the number of fibrinogen molecules bound to each cell decreases significantly, due to the progressive impairment of the specific fibrinogen-erythrocyte receptor interaction. Knowing that younger erythrocytes bind more to fibrinogen, we could presume that this population is the main contributor to the cardiovascular diseases associated with increased fibrinogen content in blood, which could disturb the blood flow. Our data also show that the sialic acids exposed on the erythrocyte membrane contribute for the interaction with fibrinogen, possibly by facilitating its binding to the erythrocyte membrane receptor

    A Rule-based Vehicular Traffic Tracking System

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    The paper presents a computer vision-based approach to the problem of vehicular traffic monitoring. The approach associates a high-level tracking system to a low-level system that performs moving vehicles detection. The high-level module is based on a large set of rules and is able to keep tracks of all moving or stopped vehicles along the image sequence

    An augmented reality based application for furnishing configuration and evaluation

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    Virtual reality as the way to display digital models and to interact with them has flourished in industrial contexts some years ago, both for design and marketing reasons. However, some specific sectors, e.g. furnishings and garments, would prefer to evaluate their products in a real environment, where their models could be easily placed, and where the interaction with them could take place in a natural way. These requirements suggested the design of an application, based on the augmented reality, which allows users placing digital models of pieces of furniture in real domestic environments, verifying their dimensional and aesthetic compatibility with the existing context, and interacting with them to test functional behavior and usability issues. Such a project would result interesting both for possible customers and for designers, because some important design hints could come from its adoption. An application prototype has been developed and tested in the field in a couple of case studies. Copyright \ua9 2011 by ASME
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