Correlation between Nafion Morphology in Various Dispersion Liquids and Properties of the Cast Membranes.

Nafion is a perfluorosulfonic acid polymer that is most commonly used in proton-exchange membrane fuel cells. The processes of pretreatment and formation of such membranes strongly affect their properties. In this work, dispersions of Nafion in various ionic forms and dispersing liquids (ethylene glycol, N,N-dimethylformamide, N-methyl-2-pyrrolidone and isopropyl alcohol-water mixtures in different ratios) were obtained and studied. Membranes fabricated by casting of the various dispersions were also studied. The effect of the nature of the dispersing liquid and the counterion on the properties of Nafion dispersions, the morphology of the polymer in the dispersions and the characteristics of the membranes obtained from them has been shown. Based on the overall results, it can be concluded that the use of perfluorosulfonic acid dispersions in aprotic polar solvents is advisable for obtaining membranes by the casting procedure. This is because it provides optimal polymer morphology in the dispersion, which leads to the formation of films with good selectivity, mechanical and transport properties. The performed investigations show the relationship between the composition of dispersions, the morphology of the polymer and the properties of the membranes formed from them by the casting procedure.

Telemedicine-based system for quality management and peer review in radiology.

OBJECTIVES: Quality assurance is the key component of modern radiology. A telemedicine-based quality assurance system helps to overcome the "scoring" approach and makes the quality control more accessible and objective. METHODS: A concept for quality assurance in radiology is developed. Its realization is a set of strategies, actions, and tools. The latter is based on telemedicine-based peer review of 23,199 computed tomography (CT) and magnetic resonance imaging (MRI) images. RESULTS: The conception of the system for quality management in radiology represents a chain of actions: "discrepancies evaluation - routine support - quality improvement activity - discrepancies evaluation". It is realized by an audit methodology, telemedicine, elearning, and other technologies. After a year of systemic telemedicine-based peer reviews, the authors have estimated that clinically significant discrepancies were detected in 6% of all cases, while clinically insignificant ones were found in 19% of cases. Most often, problems appear in musculoskeletal records; 80% of the examinations have diagnostic or technical imperfections. The presence of routine telemedicine support and personalized elearning allowed improving the diagnostics quality. The level of discrepancies has decreased significantly (p < 0.05). CONCLUSION: The telemedicine-based peer review system allows improving radiology departments' network effectiveness. MAIN MESSAGES: • "Scoring" approach to radiologists' performance assessment must be changed. • Telemedicine peer review and personalized elearning significantly decrease the number of discrepancies. • Teleradiology allows linking all primary-level hospitals to a common peer review network.