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Monte Carlo methods were applied to the reaction kinetics and polymer diffusion at play during the dynamics of creating structured latex particles. Reaction kinetic events in both the water phase and the particles are combined with diffusion of polymer radicals in the particles to allow the prediction of the overall polymerization kinetics, including the Trommsdorf gel effect, chain transfer reactions to monomer, chain transfer agents (e.g., thiols) and polymer chains, and chain length dependent termination reactions. This allowed the calculation of latex particle morphology, as well as the polymer molecular weight, gel content and graft level, when applicable. A number of examples are used to provide experimental data with which to compare the Monte Carlo predictions.magnified image

The evolution of morphology in composite latex particles is modeled under the assumption that no phase separation is allowed, resulting in fully mixed polymers in the latex particles. Such kinetically frozen, non‐equilibrium structures are easily produced when the second stage polymer is glassy at reaction temperature. For a poly[styrene‐co‐(butyl acrylate)] seed latex and a methyl methacrylate second‐stage monomer, we show the evolution of the particle structure during the polymerization process as evidenced by TEM, DSC, and surfactant titration data. Comparing these data to the model provides a mechanistic understanding of the time evolution of the particle morphology, even when a thin shell of second stage polymer is formed around a mixed core late in the reaction.

his paper outlines, from the partners' views, the background, rationale, key challenges and successes of the ICONS project. ICONS represents a case study of a successful, real-world community health initiative driven by measurement of practices and outcomes.

I Objective:To evaluate the impact of an interactive continuing medical education workshop designed to help physicians in breaking bad news to their patients. Methodology: Analysis of post-workshop questionnaires from 539 physicians assessing the retention of the key concepts and the perception of the potential impact of the workshop on their practice immediately after the workshop and six months later. Results: The most significant concepts retained by the respondents are: the need to take into consideration the whole patient (42.7% post-workshop and 45.6% of follow-up responses), the need to be prepared for the consultation (11.6% and 15%), the importance of better gUiding the interview (18.8% and 13.6%), and the value of taking more time during the consultation (5.8% and 8.3%). Analysis of paired responses on the post-workshop and the follow-up questionnaires shows that 35% of the concepts retained are identical. Conclusion:The majority of physicians retained the key concepts, both immediately following the workshop and in the longer term. Resume I Objectif: Evaluer I'impact d'un atelier de travail interactif dispense dans Ie cadre de formation rnedlcale continue pour aider les medeclns it annoncer de mauvaises nouvelles it leurs patients. Methodologie : Analyser les questionnaires remplis par 539 medecins, lmmediatement apres I'atelier et six mois plus tard afin d'avaluer Ie degre de memorisation des concepts-olea et leur perception de I'impact de cet atelier sur leur pratique. Resultats: Les concepts les plus significatifs retenus par les participants apres I'atelier et six mois plus tard sont les suivants : la necesslte de considerer Ie patient dans sa totallte (42.7 % et 45.6 %), la necessite de se preparer avant la consultation (11.6 % et 15 %), I'importance de mieux diriger I'interview (18.8 % et 13.6 %) et I'avantage de prendre plus de temps lors de la consultation. Lorsqu'on accouple les reponses des deux questionnaires I'analyse demontre que 35 % des concepts retenus demeurent les memes. Conclusion: La majortte des rnedeclns ont retenu les concepts-cles tant it la suite de I'atelier que six mois plus tard.