95 research outputs found

    Dynamical Equilibration Across a Quenched Phase Transition in a Trapped Quantum Gas

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    The formation of an equilibrium quantum state from an uncorrelated thermal one through the dynamical crossing of a phase transition is a central question of non-equilibrium many-body physics. During such crossing, the system breaks its symmetry by establishing numerous uncorrelated regions separated by spontaneously-generated defects, whose emergence obeys a universal scaling law with the quench duration. Much less is known about the ensuing re-equilibrating or "coarse-graining" stage, which is governed by the evolution and interactions of such defects under system-specific and external constraints. In this work we perform a detailed numerical characterization of the entire non-equilibrium process, addressing subtle issues in condensate growth dynamics and demonstrating the quench-induced decoupling of number and coherence growth during the re-equilibration process. Our unique visualizations not only reproduce experimental measurements in the relevant regimes, but also provide valuable information in currently experimentally-inaccessible regimes.Comment: Supplementary Movie Previes: SM-Movie-1: https://youtu.be/3q7-CvuBylg SM-Movie-2: https://youtu.be/-Gymaiv9rC0 SM-Movie-3: https://youtu.be/w-O2SPiw3nE SM-Movie-4: https://youtu.be/P4xGyr4dwK

    Echocardiography and pulse contour analysis to assess cardiac output in trauma patients.

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    Echocardiography is a valuable technique to assess cardiac output (CO) in trauma patients, but it does not allow a continuous bedside monitoring. Beat-to-beat CO assessment can be obtained by other techniques, including the pulse contour method MostCare. The aim of our study was to compare CO obtained with MostCare (MC-CO) with CO estimated by transthoracic echocardiography (TTE-CO) in trauma patients. METHODS: Forty-nine patients with blunt trauma admitted to an intensive care unit and requiring hemodynamic optimization within 24 hours from admission were studied. TTE-CO and MC-CO were estimated simultaneously at baseline, after a fluid challenge and after the start of vasoactive drug therapy. RESULTS: One hundred sixteen paired CO values were obtained. TTE-CO values ranged from 2.9 to 7.6 L·min-1, and MC-CO ranged from 2.8 to 8.2 L·min-1. The correlation between the two methods was 0.94 (95% confidence interval [CI] = 0.89 to 0.97; p<0.001). The mean bias was -0.06 L·min-1 with limits of agreements (LoA) of -0.94 to 0.82 L·min-1 (lower 95% CI, -1.16 to -0.72; upper 95% CI, 0.60 to 1.04) and a percentage error of 18%. Changes in CO showed a correlation of 0.91 (95% CI = 0.87 to 0.95; p<0.001), a mean bias of - 0.01 L·min-1 with LoA of -0.67 to 0.65 L·min-1 (lower 95% CI, -0.83 to -0.51; upper 95% CI, 0.48 to 0.81). CONCLUSION: CO measured by MostCare showed good agreement with CO obtained by transthoracic echocardiography. Pulse contour analysis can complement echocardiography in evaluating hemodynamics in trauma patients

    Medication Complications in Extracorporeal Membrane Oxygenation.

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    The need for extracorporeal membrane oxygenation (ECMO) therapy is a marker of disease severity for which multiple medications are required. The therapy causes physiologic changes that impact drug pharmacokinetics. These changes can lead to exposure-driven decreases in efficacy or increased incidence of side effects. The pharmacokinetic changes are drug specific and largely undefined for most drugs. We review available drug dosing data and provide guidance for use in the ECMO patient population

    The boundary Riemann solver coming from the real vanishing viscosity approximation

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    We study a family of initial boundary value problems associated to mixed hyperbolic-parabolic systems: v^{\epsilon} _t + A (v^{\epsilon}, \epsilon v^{\epsilon}_x ) v^{\epsilon}_x = \epsilon B (v^{\epsilon} ) v^{\epsilon}_{xx} The conservative case is, in particular, included in the previous formulation. We suppose that the solutions vϵv^{\epsilon} to these problems converge to a unique limit. Also, it is assumed smallness of the total variation and other technical hypotheses and it is provided a complete characterization of the limit. The most interesting points are the following two. First, the boundary characteristic case is considered, i.e. one eigenvalue of AA can be 00. Second, we take into account the possibility that BB is not invertible. To deal with this case, we take as hypotheses conditions that were introduced by Kawashima and Shizuta relying on physically meaningful examples. We also introduce a new condition of block linear degeneracy. We prove that, if it is not satisfied, then pathological behaviours may occur.Comment: 84 pages, 6 figures. Text changes in Sections 1 and 3.2.3. Added Section 3.1.2. Minor changes in other section

    suPAR as a prognostic biomarker in sepsis

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    Sepsis is the clinical syndrome derived from the host response to an infection and severe sepsis is the leading cause of death in critically ill patients. Several biomarkers have been tested for use in diagnosis and prognostication in patients with sepsis. Soluble urokinase-type plasminogen activator receptor (suPAR) levels are increased in various infectious diseases, in the blood and also in other tissues. However, the diagnostic value of suPAR in sepsis has not been well defined, especially compared to other more established biomarkers, such as C-reactive protein (CRP) and procalcitonin (PCT). On the other hand, suPAR levels have been shown to predict outcome in various kinds of bacteremia and recent data suggest they may have predictive value, similar to that of severity scores, in critically ill patients. This narrative review provides a descriptive overview of the clinical value of this biomarker in the diagnosis, prognosis and therapeutic guidance of sepsis
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