8 research outputs found
Leaf venation, as a resistor, to optimize a switchable IR absorber
Leaf vascular patterns are the mechanisms and mechanical support for the transportation of fluidics for photosynthesis and leaf development properties. Vascular hierarchical networks in leaves have far-reaching functions in optimal transport efficiency of functional fluidics. Embedding leaf morphogenesis as a resistor network is significant in the optimization of a translucent thermally functional material. This will enable regulation through pressure equalization by diminishing flow pressure variation. This paper investigates nature’s vasculature networks that exhibit hierarchical branching scaling applied to microfluidics. To enable optimum potential for pressure drop regulation by algorithm design. This code analysis of circuit conduit optimization for transport fluidic flow resistance is validated against CFD simulation, within a closed loop network. The paper will propose this self-optimization, characterization by resistance seeking targeting to determine a microfluidic network as a resistor. To advance a thermally function material as a switchable IR absorber
Expanding phenological insights: automated phenostage annotation with community science plant images
The relationship between cardiac resynchronization therapy and serum levels of copeptin in patients with chronic heart failure
Abstract
Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): The present study was supported by a grant from Slovak Hearth Rhythm Association (Prognostic value of MR-proANP and MR-proADM in patients undergoing cardiac resynchronization therapy).
Background
Chronic heart failure (CHF) is a complex syndrome characterized by an abnormal neurohormonal activation, including arginine vasopressin (AVP). Copeptin is an indicator of AVP activation, which levels are elevated in CHF and have prognostic importance. Cardiac resynchronization therapy (CRT) is an important device therapy for patients with advanced CHF, left ventricular (LV) systolic dysfunction and evidence of electromechanical dyssynchrony. The aim of the present study was to determine the possible relationship between CRT and serum copeptin levels.
Methods
We have included CRT patients with ischemic as well as nonischemic etiology of CHF. The levels of copeptin were measured at baseline and 12 months respectively after CRT implantation. Echocardiography was also performed pre and 12 months post CRT implantation. A CRT response was defined as a ≥ 15 % reduction in LV end-systolic volume (LVESV).
Results
The study population consisted of 41 patients. The mean copeptin level was 20.50 ± 15.77 pmol/l. Copeptin levels positively correlated with New York Heart Association class, left atrial diameter, creatinine levels and NT-proBNP levels. CRT responders have significant reduction in copeptin levels from baseline to 12 months (from 16.96 ± 12.80 pmol/l to 6.20 ± 6.44 pmol/l, p < 0.001). No significant changes in copeptin levels were observed in CRT nonresponders. Reduction > 45 % in copeptin levels was predictor of CRT-response (OR 6.72, 95 % CI 1.01 - 18.11, p = 0.045).
Conclusion
The copeptin serum levels can be a useful biomarker in the evaluation of the CRT response.
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