RESUMO
The present study reports the antibacterial disinfection properties of a series of silver nanoparticle (AgNP) immobilized membranes. Initially, polyethersulfone (PES) was functionalized through the introduction of amino groups to form aminated polyethersulfone (NH2-PES, APES). AgNPs were then coordinately immobilized on the surface of the APES composite membrane to form AgNPs-APES. The properties of the obtained membrane were examined by FT-IR, XPS, XRD, TGA, ICP-OES and SEM-EDAX analyses. These structural characterizations revealed that AgNPs ranging from 5 to 40 nm were immobilized on the surface of the polymer membrane. Antibacterial tests of the samples showed that the AgNPs-APES exhibited higher activity than the AgNPs-PES un-functionalized membrane. Generally, the AgNPs-APES 1 cm × 3 cm strip revealed a four times longer life than the un-functionalized AgNPs polymer membranes. The evaluation of the Ag(+) leaching properties of the obtained samples indicated that approximately 30% of the AgNPs could be retained, even after 12 days of operation. Further analysis indicated that silver ion release can be sustained for approximately 25 days. The present study provides a systematic and novel approach to synthesize water treatment membranes with controlled and improved silver (Ag(+)) release to enhance the lifetime of the membranes.
Assuntos
Antibacterianos/química , Nanopartículas Metálicas/química , Polímeros/química , Prata/química , Sulfonas/química , Aminação , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Membranas Artificiais , Nanopartículas Metálicas/toxicidade , Espectroscopia Fotoeletrônica , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Purificação da Água , Difração de Raios XRESUMO
In article, analysis has been carried out on the influence of recanalization of chronic total occlusion of left anterior descending artery on the course of heart failure in elderly patients who had damage to a single artery and viable myocardium. Recanalization of chronic occlusion of left anterior descending artery together with conservative therapy in elderly patients improves the clinical course of heart failure. A more significant improvement seen in patients with chronic occlusion of left anterior descending artery without history of myocardial infarction.
