Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low-or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI).Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression.

Combined molecular dynamics and ab initio computations were applied for analysis of infrared absorption and vibrational circular dichroism spectra of deoxyoctanucleotides. Unlike for previous idealized models, molecular geometries of these shorter DNA fragments in solutions were obtained as dynamic averages from simulations in a periodic water box. Vibrational spectra for the whole octamers including hydrogen-bonded solvent molecules were simulated on the basis of density-functional calculations on small fragments and subsequent transfer of molecular property tensors. Explicit and continuum solvent models were compared. Apparently, the DNA segments retain an approximate B-conformation in the aqueous solutions, but the terminal base pairs significantly deviate from the planar arrangement and the vibrational circular dichroism spectrum for (CG) 2 nucleotide indicates a larger average helical twist. Sodium counterions moved freely around the molecule during the simulation and do not influence spectral intensities. Simulated absorption spectra faithfully reproduced the experimental signal of principal functional groups, while only qualitative agreement was obtained for the dependence on the basis sequence.

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