RESUMO
Magnetic ß-cyclodextrin (ß-CD) porous polymer nanospheres (P-MCD) was fabricated by one-pot solvent thermal method using ß-CD immobilized Fe3O4 magnetic nanoparticles with tetrafluoroterephthalonitrile as the monomer. Compared with the ß-CD polymerization method reported in the literature,_ENREF_1 the synthetic route is effective and simple, thereby overcoming the harsh conditions that require nitrogen protection and always maintain anhydrous and oxygen-free. Moreover, the immobilization of ß-CD on magnetic nanoparticles is combined with the cross-linking polymerization of the cross-linker, leading to a good synergistic effect on the removal of contaminants. Meanwhile, the dispersibility of the magnetic carrier enhances the dispersion of the ß-CD porous polymer in the aqueous phase, and improves the inclusion adsorption performance and the adsorption process. P-MCD exhibited superior adsorption capacity and fast kinetics to MB. The maximum adsorption capacity of MB for P-MCD was 305.8â¯mgâ¯g -1, which is more than ß-CD modified Fe3O4 magnetic nanoparticles (Fe3O4@ß-CD). Moreover, the material had a short equilibrium time (5â¯min) for MB, high recovery and good recyclability (the adsorption efficiency was still above 86% after five repeated uses).
Assuntos
Magnetismo , Nanosferas , Poluentes Químicos da Água/química , Purificação da Água/métodos , beta-Ciclodextrinas/química , Adsorção , Cinética , Polímeros/química , PorosidadeRESUMO
In eukaryotic organisms, the correct regulation of sister chromatid cohesion, whereby sister chromatids are paired and held together, is essential for accurate segregation of the sister chromatids and homologous chromosomes into daughter cells during mitosis and meiosis, respectively. Sister chromatid cohesion requires a cohesin complex comprised of structural maintenance of chromosome adenosine triphosphatases and accessory proteins that regulate the association of the complex with chromosomes or that are involved in the establishment or release of cohesion. The cohesin complex also plays important roles in the repair of DNA double-strand breaks, regulation of gene expression and chromosome condensation. In this review, we summarize progress in understanding cohesion dynamics in plants, with the aim of uncovering differences at specific stages. We also highlight dissimilarities between plants and other eukaryotes with respect to the key players involved in the achievement of cohesion, pointing out areas that require further study.