RESUMEN
A platform for the simultaneous determination of Cd(ii) and Pb(ii) in aqueous solution has been applied based on an aluminum silicon carbide-reduced graphene oxide nanocomposite (Al4SiC4-RGO) modified bismuth film glassy carbon electrode (GCE) using square wave anodic stripping voltammetry (SWASV) for the first time. The Al4SiC4-RGO nanocomposite electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared with the Al4SiC4 modified GCE and bare GCE, the electrochemical performance of the Al4SiC4-RGO nanocomposite electrode is obviously enhanced resulting from the synergistic effects of Al4SiC4, RGO and bismuth film. The chemical and electrochemical parameters that exert an influence on the deposition and stripping of metal ions, such as supporting electrolytes, pH values, concentrations of Bi3+, deposition potentials and deposition times, were carefully studied. Under optimal conditions, a linear relationship exists between the currents and the concentrations of Cd(ii) and Pb(ii) in the range of 50 to 2700 µg L-1. The limits of detection (S/N = 3) are estimated to be 1.30 µg L-1 for Pb(ii) and 2.15 µg L-1 for Cd(ii). Compared with the related work reported in the literature, the analytical performance in this work has a lower determination limit and a wider detection linear range. In addition, this electrode also exhibits good stability and reproducibility. These results imply that the Al4SiC4-RGO nanocomposite might be a promising candidate for practical applications in the electrochemical detection of metal ions.
RESUMEN
OBJECTIVE: To explore a new method for the treatment of ankle joint fractures, and to evaluate its therapeutic effects. METHODS: Among 42 patients with ankle joint fractures, 34 patients had complete data for analysis, 19 patients were male and 15 patients were female, ranging in age from 21 to 61 years, with an average of 37 years. According to Weber-AO classification, there are 28 patients of B-type and 6 patients of C-type. The Baird and Jackson Rating System was used to evaluate therapeutic effects, and the relationship between the final function and fracture type, fracture fixation and, the time of functional training after operation were analyzed. Thirty-four patients with ankle joint fractures of B and C type were treated with internal fixation of posterior fibula plate to avoid injury of articular facet by the nails. The patients combined with the fractures of posterior malleolus were treated with fixation of both fibula and posterior malleolus through the same incision. RESULTS: All the patients were followed up ranging from 1.2 to 3.2 years, with an average of 1.8 years. According to evaluation criterion, 24 patients got an excellent result, 6 good and 4 fair, the excellent and good rate was 88.2%. CONCLUSION: The internal fixation of posterior fibula plate, as a treatment for ankle joint fractures, successfully avoids the injury of articular facet by the nails. Not only does it enhance the pullout strength of the nails, but it is able to treat the fracture of lateral malleolus and posterior malleolus with a single incision. It has provided a new way for the treatment of ankle fractures.