RESUMO
Nitrogen-doped carbon nanoparticles (N-CNPs) with a fluorescence quantum yield of 15.1％ were prepared from sucrose and urea in oleic acid medium by a one-pot solvothermal method.A new approach for quick,sensitive,and selective determination of free chlorine in water was developed based on fluorescence quenching of N-CNPs.There existed a good linear correlation between the fluorescence quenching and the concentration of ClO-in the range of 0.05-25.00 μmol/L.The limit of detection (LOD,S/N =3) was estimated to be 23 nmol/L.This method can be applied to the determination of free chlorine in real water samples.
RESUMO
Human-like collagen (HLC) was cross-linked with hyaluronic acid by genipin in different ratio. The concentrations of hyaluronic acid in the mixture were 0, 0.01%, 0.05% and 0.1%. The blood vessel tubular grafts were then fabricated by freeze-drying. Microstructure, element composite, mechanical properties, cytotoxicity grade, and biocompatibility of different vascular scaffold groups were studied by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), tensile test, burst pressure experiment, cytotoxicity experiment, endothelial cells planted in blood vessel scaffolds and hypodermic embedding of mice. The results showed that HLC-HA (0.05%) tubular scaffold exhibited interconnected well-distributed and porous structure and porosity of 94.38%; achieved the desirable mechanical property with stress of (1000.8 +/- 7.9) kPa and burst pressure of (1058.6 +/- 8.2) kPa, hypocytotoxicity, favourable cytocompatibility, hisocompatibility and disposition of degradation.
