The association between treatment adherence to nicotine patches and smoking cessation in pregnancy: a secondary analysis of a randomised controlled trial

IntroductionIn non-pregnant ‘quitters’, adherence to nicotine replacement therapy (NRT) increases smoking cessation. We investigated relationships between adherence to placebo or NRT patches and cessation in pregnancy, including an assessment of reverse causation and whether any adherence: cessation relationship is moderated when using nicotine or placebo patches. MethodsUsing data from 1050 pregnant trial participants, regression models investigated associations between maternal characteristics, adherence and smoking cessation. ResultsAdherence during the first month was associated with lower baseline cotinine concentrations (beta -0.08, 95%CI -0.15 to -0.01) and randomisation to NRT (beta 2.59, 95%CI 1.50 to 3.68). Adherence during both treatment months was associated with being randomised to NRT (beta 0.51, 95%CI 0.29 to 0.72) and inversely associated with higher nicotine dependence. Adherence with either NRT or placebo was associated with cessation at one month (OR 1.11, 95%CI 1.08 to 1.13) and delivery (OR 1.06, 95%CI 1.03 to 1.09), but no such association was observed in the subgroup where reverse causation was not possible. Amongst all women, greater adherence to nicotine patches was associated with increased cessation (OR 2.47, 95%CI 1.32 to 4.63) but greater adherence to placebo was not (OR 0.98, 95%CI: 0.44 to 2.18). ConclusionWomen who were more adherent to NRT were more likely to achieve abstinence; more nicotine dependent women probably showed lower adherence to NRT because they relapsed to smoking more quickly. The interaction between nicotine-containing patches and adherence for cessation suggests that the association between adherence with nicotine patches and cessation may be partly causal

Activity Coefficients at Infinite Dilution for Organic Compounds Dissolved in 1-Alkyl-1-methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquids Having Six-, Eight-, and Ten-Carbon Alkyl Chains

International audienceActivity coefficients at infinite dilution (gamma(proportional to)(1,2)) for 40 diverse probe solutes, including various (cyclo)alkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, ethers, nitroalkanes, and ketones, were measured by inverse gas chromatography at temperatures from 323 to 343 K in three homologous 1-alkyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquids (ILs), bearing hexyl, octyl, and decyl side chains. The retention data were further converted to gas-to-IL and water-to-IL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analyzed using the modified Abraham solvation parameter model, with the derived equations tightly correlating the experimental gas-to-IL and water-to-IL partition coefficient data to within average standard deviations of 0.088 and 0.111 log units, respectively

Theoretical prediction of partition coefficients via molecular electrostatic and electronic properties

Previously published methods for calculation of Abraham's polarity/polarizability and hydrogen bond acidity and basicity descriptors are validated for their ability to predict the various partition coefficients of 80 challenging molecules. As well as this indirect validation, accurate log P predictions are shown to be possible by using directly the fundamental molecular properties used in the calculation of descriptors. From a general point of view, the van der Waals and hydrogen bond interactions present between the solute and the water/solvent system can be represented by charge-based interactions, which are partitioned into a positive and a negative term (ΣTVMax and ΣTVMin), dipole-based interactions (μ) and induced dipole-based interactions (α); further stabilization is possible if solute and solvent densities come into contact and overlap (ΣTE). A discussion is opened on the possibility to extend this set to describe systems with electron donor/acceptor interactions other than hydrogen bonding

Theoretical prediction of the polarity/polarizability parameter pi(H)(2)

Ab initio and DFT calculations on the structure and properties of over 98 molecules are reported. Properties calculated for the molecules are assessed for their ability to correlate and predict experimentally derived values of the polarity/polarizability parameter, π. Using multivariate linear regression and partial least squares methods, four properties stand out as predictors of π: the molecular dipole moment, the polarizability, the CHelpG atomic charges and the frontier molecular orbital energies. These properties correlate π to close to the standard deviation in a previously published fragmental approach. The partial least squares method is shown to result in significantly better predictions for an external validation set