Respiratory variability of sinus node activation in humans: insights from ultra-high-density mapping.

Purpose: Experimental data suggest that shifts in the site of origin of the sinus node (SN) correlate with changes in heart rate and P wave morphology. The direct visualization of the effect of respiration on SN electrical activation has not yet been reported in humans. We aimed to measure the respiratory shifting of the SN activation using ultra-high-density mapping.

Synthesis, molecular properties and comparative docking and QSAR of new 2-(7-hydroxy-2-oxo-2H-chromen-4-yl)acetic acid derivatives as possible anticancer agents.

Novel coumarin amino acid derivatives were synthesized. The structure of synthesized compounds has established on basis of different spectral data. The optimization geometry, frontier molecular orbitals (FMOs), thermodynamic parameters and chemical reactivity, were discussed using DFT\B3LYP by 6-311G* basis set, to identify a clear view for inter and intramolecular interaction of tested compounds.