0000000000571108
AUTHOR
A. Shirazi
SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study
Abstract Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in su…
Surfactant Association: Recent Theoretical and Experimental Developments
A theoretical model describing the association of ionic surfactants into rod-shaped micelles is combined with an approximate formula for the viscosity increase induced by rod-shaped aggregates. It is shown that most of the thermodynamic parameters of the association model can be obtained from viscosity measurements. The approach is applied to micellar solutions of hexadecylpyridinium salts. The pronounced effect of counter-ion concentration on the growth of rod-shaped micelles can be attributed to a slightly higher degree of counter-ion association in the cylindrical part than in the end portions. An attempt is made to explain the finding that the degree of counter-ion association is virtua…