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Steady-state and time-resolved emission spectroscopic techniques have been employed to characterize the coumarin species and identify which species is solubilized in the hydrocarbon core micelles of triton X-100 (neutral), hexadecyltrimethyl ammonium bromide (cationic) and dodecyl lithium sulfate (anionic) solutions under physiological conditions at 77 K. The emission and absorption spectra for the following species of coumarin-monomer, hydrogenbonded complex, molecular aggregation and strong hydrophobic aggregates-were recorded in methylcyclohexane (MCH), ethanol, buffers and aqueous solutions. The fluorescence and phosphorescence emissions of monomer in MCH at 77 K are assigned as resulting from 1(pi, pi*)1 and 3(pi, pi*)1 states, respectively, originated from the ethylenic bond and carbonyl of the pyrone ring. Molecular orbital calculations using the Hydrogenic Atoms in Molecule, version 3, method were carried out to help interpretation of the spectroscopic results. The photophysical properties from each species are used to probe which species penetrates in the hydrophobic region of micelles. It was found that a fifth species of coumarin assigned as the "action species" is solubilized into the interior of micelles. These observations could lend some insight into the mechanism of transporting coumarins across the membrane.

Abstract— The emitting chromophores, emitting states, state orderings and phosphorescence lifetimes of neutral, hydrogen‐bonded, and protonated dibucaines in water/alcohol mixtures were determined experimentally and were confirmed theoretically using a HAM/3 method. These photophysical properties are used to probe the deprotonation dynamics of dibucaine‐HCl in the water/hydrophobic media. It is found that the protonated dibucaine in an aqueous solution is deprotonated and/or forms hydrogen‐bonded dibucaine when it is brought into contact with the alcohols and surfactants. The observed deprotonation processes could lend some insight on the molecular basis of pharmacological action of dibucaine.

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This paper observes the growing influence of designers and programmers in the journalistic work within online newsrooms. Described as "tecnoactors", these professionals acquire visibilityby mastering professional expertise, decisive in the production of news. The purpose here is to investigate how journalists, designers and programmers establish negotiations during production routines. The empirical study is delimited to six online newsrooms-three from Brazil and three from Portugal-where 17 semi-structured interviews with members of the professional categories were made. The qualitative analysis focus onfour themes: 1) negotiation processes; 2) news concept; 3) physical distance versus epistemic distance; 4) professional hybridity.