452 research outputs found

    Ventricular constraint in dilated cardiomyopathy: A new, compliant textile mesh exerts prophylactic and therapeutic properties

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    BackgroundDilated cardiomyopathy is associated with a progressive decrease in cardiac function, leading to end-stage heart failure. We aimed to stop this process by mechanically constraining the heart with a new, compliant textile mesh.MethodsIn 16 male Munich minipigs (50 ± 7 kg), dilated cardiomyopathy with congestive heart failure was induced through 4 weeks of rapid ventricular pacing (220 beats/min). In the early-mesh group (n = 8), a polyvinylidene fluoride mesh was positioned around both ventricles before pacing was started. In the other group (n = 8), experimental dilated cardiomyopathy through rapid pacing was induced (no mesh). After mesh grafting, rapid pacing was continued (late mesh).ResultsRapid pacing in the no-mesh group (control group) significantly decreased both systolic (cardiac output, peak systolic pressure, and the derivative of pressure increase [dP/dtmax]) and diastolic (minimum rate of pressure rise [dP/dtmin] and left ventricular end-diastolic pressure) variables, whereas these variables remained almost unchanged in the early-mesh group. In the late-mesh group the passive-elastic constraint not only prevented further deterioration but even exerted reverse remodeling to some extent (dP/dtmax and left ventricular end-diastolic pressure, P < .05).ConclusionsVentricular constraint with the new mesh seems to be a prophylactic and therapeutic option in cardiac insufficiency caused by ventricular dilation. This passive-elastic cardioplasty induced reverse remodeling of dilated hearts and significantly improved diastolic and systolic ventricular function

    Differential Geometry applied to Acoustics : Non Linear Propagation in Reissner Beams

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    Although acoustics is one of the disciplines of mechanics, its "geometrization" is still limited to a few areas. As shown in the work on nonlinear propagation in Reissner beams, it seems that an interpretation of the theories of acoustics through the concepts of differential geometry can help to address the non-linear phenomena in their intrinsic qualities. This results in a field of research aimed at establishing and solving dynamic models purged of any artificial nonlinearity by taking advantage of symmetry properties underlying the use of Lie groups. The geometric constructions needed for reduction are presented in the context of the "covariant" approach.Comment: Submitted to GSI2013 - Geometric Science of Informatio

    Strain-Based Analysis for Geometrically Nonlinear Beams: A Modal Approach

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97066/1/AIAA2012-1713.pd

    Social navigation

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    In this chapter we present one of the pioneer approaches in supporting users in navigating the complex information spaces, social navigation support. Social navigation support is inspired by natural tendencies of individuals to follow traces of each other in exploring the world, especially when dealing with uncertainties. In this chapter, we cover details on various approaches in implementing social navigation support in the information space as we also connect the concept to supporting theories. The first part of this chapter reviews related theories and introduces the design space of social navigation support through a series of example applications. The second part of the chapter discusses the common challenges in design and implementation of social navigation support, demonstrates how these challenges have been addressed, and reviews more recent direction of social navigation support. Furthermore, as social navigation support has been an inspirational approach to various other social information access approaches we discuss how social navigation support can be integrated with those approaches. We conclude with a review of evaluation methods for social navigation support and remarks about its current state

    Species diversity of Trichoderma in Poland

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    In the present study, we reinvestigate the diversity of Trichoderma in Poland utilizing a combination of morphological and molecular/phylogenetic methods. A total of 170 isolates were collected from six different substrata at 49 sites in Poland. These were divided among 14 taxa as follows: 110 of 170 Trichoderma isolates were identified to the species level by the analysis of their ITS1, ITS2 rDNA sequences as: T. harzianum (43 isolates), T. aggressivum (35), T. citrinoviride (11), T. hamatum (9), T. virens (6), T. longibrachiatum (4), T. polysporum (1), and T. tomentosum (1); 60 isolates belonging to the Viride clade were identified based on a fragment of the translation-elongation factor 1-alpha (tef1) gene as: T. atroviride (20 isolates), T. gamsii (2), T. koningii (17), T. viridescens (13), T. viride (7), and T. koningiopsis (1). Identifications were made using the BLAST interface in TrichOKEY and TrichoBLAST (http://www.isth.info). The most diverse substrata were soil (nine species per 22 isolates) and decaying wood (nine species per 75 isolates). The most abundant species (25%) isolated from all substrata was T. harzianum

    Developing a pragmatic evaluation of ICTs for older adults with cognitive impairment at scale : the IN LIFE experience

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    Implementing information and communications technology (ICT) at scale requires evaluation processes to capture the impact on users as well as the infrastructure into which it is being introduced. For older adults living with cognitive impairment, this requires evaluation that can accommodate different levels of cognitive impairment, alongside input from family and formal caregivers, plus stakeholder organisations. The European Horizon 2020 project INdependent LIving support Functions for the Elderly (IN LIFE) set out to integrate 17 technologies into a single digital platform for older people living with cognitive impairment plus their families, care providers and stakeholders. The IN LIFE evaluation took place across six national pilot sites to examine a number of variables including impact on the users, user acceptance of the individual services and the overall platform, plus the economic case for the IN LIFE platform. The results confirmed the interest and need among older adults, family caregivers, formal caregivers and stakeholders, for information and communications technology (ICT). Relative to the baseline, quality of life improved and cognition stabilised; however, there was an overall reluctance to pay for the platform. The findings provide insights into existing barriers and challenges for adoption of ICT for older people living with cognitive impairment
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