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This paper shows some studies carried out throughout these two decades at the Center for Technological Applications and Nuclear Development (CEADEN) in the field of radiomodification and synthesis of polymeric materials through the use of ionizing radiation to obtain polymers by grafting, radiosterilization and purification of a natural polymer: sodium alginate, obtaining a copolymer of 2-hydroxyethyl methacrylate (HEMA) and acrylamide, preparing hydrogel dressings from polyvinylpyrrolidone (PVP) for topical use, with two clinical trials were carried out in hospitals in Havana and CEADEN received the medical record from the Center for State Control of Medications, Equipment and Medical Devices (CEDMED) as a regulatory body, in the end it was describes the production of PVP and PVP-silver nanogels for controlled release. [ABSTRACT FROM AUTHOR]

A great amount of gaseous pollutants are discharged directly into the atmosphere including VOCs due to industrial activity. Gaseous phase of photooxidation consisting of continuous irradiation of a catalyst based on TiO2, shows potential uses in removing VOCs in airstreams; in this sense and with regard to technology, the main challenge is the design and optimization of the reactor to get both high residence times and high degradation levels. That is why the basic aspects of heterogeneous photocatalysis in the gaseous phase, the concept of photoreactors and their developing, both in their beginnigs and in their evolution in the search for better removal efficiency and optimization of irradiation sources are presented here. [ABSTRACT FROM AUTHOR]

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One of the most important requirements that all methods of protein purification for intravenous use must fulfil is the elimination or dissociation of the immunoglobulin aggregates. The use of gel filtration and espectrophotometric techniques showed that acid pH (4.5), gives greater molecular stability to the IgG, dissociating most of the aggregates during lengthy storage using dextrose (5%) as stabilizer, this fact is influenced by the ionic strength of the medium for each pH. Samples with polymers (1-3%) lose them in 6 months. At the same time the use of pH 4.0 showed advantages as the non formation of polymers during the heat of the immunoglobulins, as compared to more basic pH. After 5 minutes of heating the sample at pH 7.0 the absorbance increased in 60% in comparison with the sample at pH 4.0. [ABSTRACT FROM AUTHOR]