Determination of the total antioxidant capacity of the Chinese tea based on a novel "peroxidase/zirconium phosphonate"composite electrochemical sensor.

In this work, a novel zirconium phosphonate (ZrPR1R2) was prepared by decorating both the aminoethoxy- group (R1) and the carboxypropyl- group (R2) on the zirconium phosphate layers in order to manipulate further the immobilization of the peroxidase (POD), and an antioxidant biosensor with higher sensitivity was constructed by dropping the POD/ZrPR1R2 composite onto the glassy carbon electrode surface. The activity of the POD/ZrPR1R2 composite was detected by Uv-vis spectra. The direct electrochemical behavior, the electrocatalytic response to dissolved oxygen and hydrogen peroxide, as well as the ability to detect total antioxidant capacity in tea sample were investigated by the methods of cyclic voltammetry. The results indicated that the immobilization of POD in ZrPR1R2 nanosheets matrix enhanced the enzymatic activity, and achieved the fast and direct electron transfer between POD and glassy carbon electrode. Moreover, the POD/ZrPR1R2 composite modified electrode show the electrocatalytic response to hydrogen peroxide in the linear range of 8.8×10-8 to 8.8×10-7 mol L-1, with the detection limit of 3.3×10-8 mol L-1. Attributing to the sensitive response to dissolved oxygen, the total antioxidant capacity can be detected directly in the real tea water by this POD/ZrPR1R2 composite modified electrode.

[The effects of 40 mg atorvastatin on serum lipids, inflammatory markers and clinical events in ACS patients post PCI].

OBJECTIVE: To assess the safety and effects of 40 mg atorvastatin on serum lipids, inflammatory markers and clinical events in ACS patients post PCI. METHODS: A total of 92 patients with ACS post successful PCI were randomly divided into atorvastatin 10 mg/d (group A) and atorvastatin 40 mg/d (group B) on top of the standard medical therapy. Blood were taken at baseline, 4, 12 and 24 weeks for serum alanine aminotransferase (ALT), lipids, high-sensitive C-reactive protein (hs-CRP) and matrix metalloprotease-9 (MMP-9) measurements. The major adverse cardiac events (MACE) were also observed. RESULTS: There was no significant difference in medication withdrawn (2 vs. 3 cases) due to increased ALT (3 times higher than normal) and incidence of MACE (5 vs. 7 cases) between the groups. TC and LDL were significantly reduced in both groups 4 weeks and thereafter post medication compared to pre-treatment (P < 0.05) and the reduction was more significant in group B than that in group A at 24 weeks post medication (P < 0.05) while TG and HDL remained unchanged. hs-CRP was significantly reduced at 12 and 24 weeks in both groups compared to baseline and the reduction was more significant in group B than that in group A at 24 weeks. MMP-9 was significantly reduced in both groups 4 weeks and thereafter post medication compared to pre-treatment (P < 0.05) and the reduction was more significant in group B than that in group A at 12 weeks post medication (P < 0.05). CONCLUSION: Both atorvastatin doses significantly reduced TC, LDL, hs-CRP and MMP-9 in ACS patients post PCI and the reduction was more significant in high dose atorvastatin group at 24 weeks while the MACE and drug withdraw rates were similar between the groups.