32 research outputs found

    Serum Cystatin C as an Early Marker of Neutrophil Gelatinase‐associated Lipocalin‐positive Acute Kidney Injury Resulting from Cardiopulmonary Bypass in Infants with Congenital Heart Disease

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    ObjectiveAcute kidney injury (AKI) is a common complication resulting from cardiopulmonary bypass in infants. Urinary neutrophil gelatinase‐associated lipocalin (NGAL) is a sensitive and specific marker of such injury. In this study, we compared the performance of serum cystatin C (Cys C) and serum creatinine (Cr) as early markers of renal dysfunction in infants undergoing cardiac surgery under bypass.Study Design, Setting, and PatientsThe study was designed as a prospective observational study. The study was conducted in the cardiac intensive care unit (ICU) of a tertiary, academic children's hospital in the United States. Infants (age <1 year) undergoing cardiac surgery under cardiopulmonary bypass were included in the study.Outcome MeasureAcute kidney injury was defined based on postoperative urinary NGAL.ResultsA total of 17 infants were included in the study, and five of them developed AKI. Serum Cys C and Cr levels were measured postoperatively on days 1, 2, and 3, and compared with baseline levels. On postoperative day 2, infants with AKI showed significant change from baseline in serum Cys C levels compared with non‐AKI infants (28% vs. −9%, P = .03). The two groups did not show significant differences with respect to rise in serum Cr on any of the 3 postoperative days. Serum Cr on days 1 and 2 showed nonspecific increases in both AKI and non‐AKI groups. The area under the receiver operating characteristic curve for day 2 Cys C was 0.87 (95% CI 0.67–1.00) in recognizing NGAL‐positive AKI.ConclusionsPostoperative serum Cys C appears to be a more specific and sensitive biomarker for NGAL‐positive AKI resulting from cardiopulmonary bypass surgery in infants undergoing cardiac surgery.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113151/1/chd12253.pd

    Importance Sampling in Rigid Body Diffusion Monte Carlo

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    We present an algorithm for rigid body diffusion Monte Carlo with importance sampling, which is based on a rigorous short-time expansion of the Green's function for rotational motion in three dimensions. We show that this short-time approximation provides correct sampling of the angular degrees of freedom, and provides a general way to incorporate importance sampling for all degrees of freedom. The full importance sampling algorithm significantly improves both calculational efficiency and accuracy of ground state properties, and allows rotational and bending excitations in molecular van der Waals clusters to be studied directly.Comment: Accepted for publication in Computer Physics Communication

    Effects of molecular rotation on densities in doped [sup 4]He clusters

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    International audienceThe effects of including rotational degrees of freedom on helium solvation densities in molecule-doped helium clusters are investigated for a variety of molecules. Helium densities and cluster energetics are calculated with diffusion Monte Carlo methods. The rotationally induced changes in the helium density distributions are examined and quantified with a theoretical estimator applicable to molecules of arbitrary symmetry. This analysis leads to a discussion of adiabatic following of molecular rotation in a solvating helium environment. We make a detailed comparative study of the effect of molecular rotation as a function of four impurity molecules with varying mass and symmetry: SF6, OCS, HCN, and benzene (C6H6). We find that even for the heaviest rotors, only a fraction of the solvating helium density adiabatically follows the molecular motion in the quantum ground state. For the lightest molecule, HCN, a negligible degree of adiabatic following is found. A discussion of the various definitions is presented to clarify the meaning of adiabatic following, and its applicability to dynamical models of quantum rotation in helium droplets is evaluated in light of the quantitative findings of incomplete adiabatic following established here

    Synthesis and Spectral Characterization of Some New 4-(2,6-Diarylpyridin-4-yl)-<i>2H</i>-chromen-2-ones

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    <div><p></p><p>Some new 4-(2,6-diarylpyridin-4-yl)-<i>2H</i>-chromen-2-one derivatives <b>5a–l</b> have been synthesized by reacting 4-(3-oxo-3-arylprop-1-enyl)-<i>2H</i>-chromen-2-ones <b>3a–c</b> with appropriate 1-(2-oxo-2-arylethyl)pyridinium bromide salt <b>4a–d</b> in the presence of ammonium acetate in refluxing glacial acetic acid. The newly synthesized compounds have been characterized by elemental and spectral analysis.</p> </div

    Timing of pediatric pyloromyotomy on hospital length of stay

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    Introduction: Pyloromyotomy timing is predicated upon correction of electrolyte abnormalities. Among infants who presented with normal electrolytes, we hypothesized that pyloromyotomy the evening of presentation, rather than waiting until morning, would confer shorter length of stay (LOS). Methods: This single-center retrospective cohort study included patients who underwent pyloromyotomy from 2012 to 2021. Exposure was time of operation with nighttime considered between the times of 17:00 and 06:59 and daytime between 07:00 and 16:59. A 2:1 daytime to nighttime match was performed among patients who presented with normal electrolytes with Fisher's Exact and Student's t-test for comparisons. Results: Of 520 patients, 15 (3%) underwent pyloromyotomy overnight and were matched to 30 daytime patients. There were no differences in median age (33 days (interquartile range [IQR] 29–44) vs 32 days (IQR 25–44)), male sex (15 (100%) vs 28 (93.3%), or history of prematurity (0 (0%) vs 2 (6.7%)) for nighttime compared to daytime, respectively. Operative outcomes including conversion to open, duodenal perforation, incomplete myotomy, or surgical site infection did not differ between the groups. While the nighttime group had a significantly shorter time from presentation to operating room (OR) than the daytime group (5.3 vs 15.9 h), there were no significant differences in total LOS (45.7 vs 57.3 h, p = 0.13). Conclusion: For infants with hypertrophic pyloric stenosis who present with normal electrolytes, it is safe to offer operation same-day or following a night of hydration. There was no evidence of improved hospital utilization for patients undergoing pyloromyotomy the night of presentation
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