Improved Selective Cholesterol Adsorption By Molecularly Imprinted Poly(methacrylic Acid)/silica (pmaa-sio₂) Hybrid Material Synthesized With Different Molar Ratios.

The present paper describes the synthesis of molecularly imprinted polymer - poly(methacrylic acid)/silica and reports its performance feasibility with desired adsorption capacity and selectivity for cholesterol extraction. Two imprinted hybrid materials were synthesized at different methacrylic acid (MAA)/tetraethoxysilane (TEOS) molar ratios (6:1 and 1:5) and characterized by FT-IR, TGA, SEM and textural data. Cholesterol adsorption on hybrid materials took place preferably in apolar solvent medium, especially in chloroform. From the kinetic data, the equilibrium time was reached quickly, being 12 and 20 min for the polymers synthesized at MAA/TEOS molar ratio of 6:1 and 1:5, respectively. The pseudo-second-order model provided the best fit for cholesterol adsorption on polymers, confirming the chemical nature of the adsorption process, while the dual-site Langmuir-Freundlich equation presented the best fit to the experimental data, suggesting the existence of two kinds of adsorption sites on both polymers. The maximum adsorption capacities obtained for the polymers synthesized at MAA/TEOS molar ratios of 6:1 and 1:5 were found to be 214.8 and 166.4 mg g(-1), respectively. The results from isotherm data also indicated higher adsorption capacity for both imprinted polymers regarding to corresponding non-imprinted polymers. Nevertheless, taking into account the retention parameters and selectivity of cholesterol in the presence of structurally analogue compounds (5-α-cholestane and 7-dehydrocholesterol), it was observed that the polymer synthesized at the MAA/TEOS molar ratio of 6:1 was much more selective for cholesterol than the one prepared at the ratio of 1:5, thus suggesting that selective binding sites ascribed to the carboxyl group from MAA play a central role in the imprinting effect created on MIP.

Prolongamento da amamentação após o primeiro ano de vida: argumentos das mães

This paper aims to identify and analyze the reasons pointed by mothers to prolong breastfeeding beyond the first year of the child s life. The study involved 40 mothers whose children were treated in the Preventive Program of Research and Dental Treatment Center for Special Patients - Dental School of Piracicaba - UNICAMP. The group consisted of mothers who prolonged the breastfeeding beyond the baby s first year of life. All mothers were surveyed by a researcher using a specific questionnaire. In order to avoid information loss, the interviews were taped, then transcripted. Results showed that the main cause of the extended breastfeeding was maternal pleasure. It was also observed that the mother and infant attachment favors prolonged breastfeeding occurrence. Further studies should be carried out for more accurate functional analyses of variable that lead to extend breastfeeding or to wean.

A Educação Física no contexto da nova estrutura do ensino fundamental : uma proposta para o primeiro ano

Universidade Estadual de Campinas . Faculdade de Educação Física

Bem-vinda à escola : o ingresso da criança no primeiro ano do ensino fundamental sob o olhar docente e a perspectiva do brincar

Universidade Estadual de Campinas . Faculdade de Educação Física

Avaliação postural em escolares das redes estadual e particular de ensino de primeiro grau

Universidade Estadual de Campinas . Faculdade de Educação Física