462 research outputs found

    Effects of donor cause of death, ischemia time, inotrope exposure, troponin values, cardiopulmonary resuscitation, electrocardiographic and echocardiographic data on recipient outcomes: A review of the literature

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    BackgroundHeart transplantation has become standard of care for pediatric patients with either end‐stage heart failure or inoperable congenital heart defects. Despite increasing surgical complexity and overall volume, however, annual transplant rates remain largely unchanged. Data demonstrating pediatric donor heart refusal rates of 50% suggest optimizing donor utilization is critical. This review evaluated the impact of donor characteristics surrounding the time of death on pediatric heart transplant recipient outcomes.MethodsAn extensive literature review was performed to identify articles focused on donor characteristics surrounding the time of death and their impact on pediatric heart transplant recipient outcomes.ResultsPotential pediatric heart transplant recipient institutions commonly receive data from seven different donor death‐related categories with which to determine organ acceptance: cause of death, need for CPR, serum troponin, inotrope exposure, projected donor ischemia time, electrocardiographic, and echocardiographic results. Although DITs up to 8 hours have been reported with comparable recipient outcomes, most data support minimizing this period to <4 hours. CVA as a cause of death may be associated with decreased recipient survival but is rare in the pediatric population. Otherwise, however, in the setting of an acceptable donor heart with a normal echocardiogram, none of the other data categories surrounding donor death negatively impact pediatric heart transplant recipient survival.ConclusionsEchocardiographic evaluation is the most important donor clinical information following declaration of brain death provided to potential recipient institutions. Considering its relative importance, every effort should be made to allow direct image visualization.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154939/1/petr13676.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154939/2/petr13676_am.pd

    A novel type of intermittency in a nonlinear dynamo in a compressible flow

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    The transition to intermittent mean--field dynamos is studied using numerical simulations of isotropic magnetohydrodynamic turbulence driven by a helical flow. The low-Prandtl number regime is investigated by keeping the kinematic viscosity fixed while the magnetic diffusivity is varied. Just below the critical parameter value for the onset of dynamo action, a transient mean--field with low magnetic energy is observed. After the transition to a sustained dynamo, the system is shown to evolve through different types of intermittency until a large--scale coherent field with small--scale turbulent fluctuations is formed. Prior to this coherent field stage, a new type of intermittency is detected, where the magnetic field randomly alternates between phases of coherent and incoherent large--scale spatial structures. The relevance of these findings to the understanding of the physics of mean--field dynamo and the physical mechanisms behind intermittent behavior observed in stellar magnetic field variability are discussed.Comment: 19 pages, 13 figure

    Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

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    We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η\eta|<0.8) and transverse momentum range 0.2< pTp_{\rm T}< 5.0 GeV/cc. The elliptic flow signal v2_2, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ±\pm 0.002 (stat) ±\pm 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v2(pT)_2(p_{\rm T}) reaches a maximum of 0.2 near pTp_{\rm T} = 3 GeV/cc. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

    Characterization of pulmonary function in 10â18 year old patients with Duchenne muscular dystrophy

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    Pulmonary function loss in patients with Duchenne muscular dystrophy (DMD) is progressive and leads to pulmonary insufficiency. The purpose of this study in 10â18 year old patients with DMD is the assessment of the inter-correlation between pulmonary function tests (PFTs), their reliability and the association with the general disease stage measured by the Brooke score. Dynamic PFTs (peak expiratory flow [PEF], forced vital capacity [FVC], forced expiratory volume in one second [FEV1]) and maximum static airway pressures (MIP, MEP) were prospectively collected from 64 DMD patients enrolled in the DELOS trial (ClinicalTrials.gov, number NCT01027884). Baseline PEF percent predicted (PEF%p) was <80% and patients had stopped taking glucocorticoids at least 12 months prior to study start. At baseline PEF%p, FVC%p and FEV1%p correlated well with each other (Spearman's rho: PEF%pâFVC%p: 0.54; PEF%pâFEV1%p: 0.72; FVC%pâFEV1%p: 0.91). MIP%p and MEP%p correlated well with one another (MIP%pâMEP%p: 0.71) but less well with PEF%p (MIP%pâPEF%p: 0.40; MEP%pâPEF%p: 0.41) and slightly better with FVC%p (MIP%pâFVC%p: 0.59; MEP%pâFVC%p: 0.74). The within-subject coefficients of variation (CV) for successive measures were 6.97% for PEF%p, 6.69% for FVC%p and 11.11% for FEV1%p, indicating that these parameters could be more reliably assessed compared to maximum static airway pressures (CV for MIP%p: 18.00%; MEP%p: 15.73%). Yearly rates of PFT decline (placebo group) were larger in dynamic parameters (PEF%p: â8.9% [SD 2.0]; FVC%p: â8.7% [SD 1.1]; FEV1%p: â10.2% [SD 2.0]) than static airway pressures (MIP%p: â4.5 [SD 1.3]; MEP%p: â2.8 [SD 1.1]). A considerable drop in dynamic pulmonary function parameters was associated with loss of upper limb function (transition from Brooke score category 4 to category 5). In conclusion, these findings expand the understanding of the reliability, correlation and evolution of different pulmonary function measures in DMD patients who are in the pulmonary function decline phase

    Reassessing the Impact of High Performance Workplaces

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    High performance workplace practices were extolled as an efficient means to increase firm productivity. The empirical evidence is disputed, however. To assess the productivity effects of a broad variety of measures, we simultaneously account for both unobserved heterogeneity and endogeneity using establishment panel data for Germany. We show that increasing employee participation enhances firm productivity in Germany, whereas incentive systems do not foster productivity. Our results further indicate that firms with structural productivity problems tend to introduce organisational changes that increase employee participation whereas well performing firms are more likely to offer incentives
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