Repeated bedside echocardiography in children with respiratory failure

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to verify the benefits and limitations of repeated bedside echocardiographic examinations in children during mechanical ventilation. For the purposes of this study, we selected the data of over a time period from 2006 to 2010.</p> <p>Methods</p> <p>A total of 235 children, average age 3.21 (SD 1.32) years were included into the study and divided into etiopathogenic groups. High-risk groups comprised: Acute lung injury and acute respiratory distress syndrome (ALI/ARDS), return of spontaneous circulation after cardiopulmonary resuscitation (ROSC), bronchopulmonary dysplasia (BPD), cardiomyopathy (CMP) and cardiopulmonary disease (CPD). Transthoracic echocardiography was carried out during mechanical ventilation. The following data were collated for statistical evaluation: right and left ventricle myocardial performance indices (RV MPI; LV MPI), left ventricle shortening fraction (SF), cardiac output (CO), and the mitral valve ratio of peak velocity of early wave (E) to the peak velocity of active wave (A) as E/A ratio. The data was processed after a period of recovery, i.e. one hour after the introduction of invasive lines (time-1) and after 72 hours of comprehensive treatment (time-2). The overall development of parameters over time was compared within groups and between groups using the distribution-free Wilcoxons and two-way ANOVA tests.</p> <p>Results</p> <p>A total of 870 echocardiographic examinations were performed. At time-1 higher average values of RV MPI (0.34, SD 0.01 vs. 0.21, SD 0.01; p < 0.001) were found in all groups compared with reference values. Left ventricular load in the high-risk groups was expressed by a higher LV MPI (0.39, SD 0.13 vs. 0.29, SD 0.02; p < 0.01) and lower E/A ratio (0.95, SD 0.36 vs. 1.36, SD 0.64; p < 0.001), SF (0.37, SD 0.11 vs. 0.47, SD 0.02; p < 0.01) and CO (1.95, SD 0.37 vs. 2.94, SD 1.03; p < 0.01). At time-2 RV MPI were lower (0.25, SD 0.02 vs. 0.34, SD 0.01; p < 0.001), but remained higher compared with reference values (0.25, SD 0.02 vs. 0.21, SD 0.01; p < 0.05). Other parameters in high-risk groups were improved, but remained insignificantly different compared with reference values.</p> <p>Conclusion</p> <p>Echocardiography complements standard monitoring of valuable information regarding cardiac load in real time. Chest excursion during mechanical ventilation does not reduce the quality of the acquired data.</p

Not Available

Not AvailableFOR DETERMINING THE OPTIMUM SIZE AND THICKNESS OF POLYTHENE BAGS, FOUR SIZES VIZ 25 CM X 15CM X 30CM X 40CM X 25 CMX 45CM X 30CM WITH GAUGES 150, 200 AND 250 WERE TESTED FOR RAISING NURSERY OF EUCALYPTUS HYBRID. THE DATA SHOWED CONSISTANT CONCOMITANT INCREASE IN THE GROWTH PARAMETERS WITH INCREASING SIZE AND THICKNESS OF POLYTHENE BAGS. ON CONSIDERING THE COST AND GROSS RETURN FROM SIX YEAR OLD PLANTATION RAISED FROM THE SEEDLINGS IN THE BAGS UNDER TEST , OPTIMUM SIZE AND THICKNESS OF BAG WORKS OUT TO 40 CM X 25 CM WITH 200 GAUGE FOLLOWED BY 45 CM X 30 CM WITH 150 GAUGE.Not Availabl

The voltage-sensitive dye RH421 detects a Na⁺,K⁺-ATPase conformational change at the membrane surface

© 2017 Elsevier B.V. RH421 is a voltage-sensitive fluorescent styrylpyridinium dye which has often been used to probe the kinetics of Na+,K+-ATPase partial reactions. The origin of the dye's response has up to now been unclear. Here we show that RH421 responds to phosphorylation of the Na+,K+-ATPase by inorganic phosphate with a fluorescence increase. Analysis of the kinetics of the fluorescence response indicates that the probe is not detecting phosphorylation itself but rather a shift in the protein's E1/E2 conformational equilibrium induced by preferential phosphate binding to and phosphorylation of enzyme in the E2 conformation. Molecular dynamics simulations of crystal structures in lipid bilayers indicate some change in the protein's hydrophobic thickness during the E1-E2 transition, which may influence the dye response. However, the transition is known to involve significant rearrangement of the protein's highly charged lysine-rich cytoplasmic N-terminal sequence. Using poly-L-lysine as a model of the N-terminus, we show that an analogous response of RH421 to the E1 → E2P conformational change is produced by poly-L-lysine binding to the surface of the Na+,K+-ATPase-containing membrane fragments. Thus, it seems that the prime origin of the RH421 fluorescence response is a change in the interaction of the protein's N-terminus with the surrounding membrane. Quantum mechanical calculations of the dye's visible absorption spectrum give further support to this conclusion. The results obtained indicate that membrane binding and release of the N-terminus of the Na+,K+-ATPase α-subunit are intimately involved in the protein's catalytic cycle and could represent an effective site of regulation

Numerical Simulation of Delft-Jet-in-Hot-Coflow (DJHC) Flames Using the Eddy Dissipation Concept Model for Turbulence–Chemistry Interaction

In this paper, we report results of a numerical investigation of turbulent natural gas combustion for a jet in a coflow of lean combustion products in the Delft-Jet-in-Hot-Coflow (DJHC) burner which emulates MILD (Moderate and Intense Low Oxygen Dilution) combustion behavior. The focus is on assessing the performance of the Eddy Dissipation Concept (EDC) model in combination with two-equation turbulence models and chemical kinetic schemes for about 20 species (Correa mechanism and DRM19 mechanism) by comparing predictions with experimental measurements.We study two different flame conditions corresponding to two different oxygen levels (7.6% and 10.9% by mass) in the hot coflow, and for two jet Reynolds number (Re = 4,100 and Re = 8,800). The mean velocity and turbulent kinetic energy predicted by different turbulence models are in good agreement with data without exhibiting large differences among the model predictions. The realizable k-? model exhibits better performance in the prediction of entrainment. The EDC combustion model predicts too early ignition leading to a peak in the radial mean temperature profile at too low axial distance. However the model correctly predicts the experimentally observed decreasing trend of lift-off height with jet Reynolds number. A detailed analysis of the mean reaction rate of the EDC model is made and as possible cause for the deviations between model predictions and experiments a low turbulent Reynolds number effect is identified. Using modified EDC model constants prediction of too early ignition can be avoided. The results are weakly sensitive to the sub-model for laminar viscosity and laminar diffusion fluxes.Multi-Scale PhysicsApplied Science