Objective:To determine the content of copper and zinc in tea by flame atomic absorption spectrophotometry and to investigate the influence on the content after leached for different time. Methods:The tea samples were leached for different time by boiling water and then the content of copper and zinc was determinated by flame atomic absorption spectrophotometry. Results:When the leaching time was less than 10 min, the content of copper and zinc increased significantly with the prolongation of the leaching time, while the increase was not obvious when the leaching time was more than 10 min. Copper and zinc showed good linearity in the range of 0.02-0.15 mg/L and 0.05-0.30 mg/L,separately. The recovery was in the range of 98.5%-101.1%for copper and 98.7%-101.2%for zinc with the RSD of 0.8%in copper and zinc (n=9) . Conclusion:The method is suitable to determine the content of copper and zinc in tea. Leaching time can influence the content of copper and zinc in tea significantly.

Objective To investigate the efficacy and safety of endoscopic retrograde cholangiopancreatography (ERCP)+SpyGlass system versus percutaneous transhepatic gallbladder drainage (PTGD)+ERCP in the treatment of acute cholecystitis secondary to choledocholithiasis. Methods A retrospective analysis was performed for the clinical data of the patients with acute cholecystitis secondary to choledocholithiasis who were treated in Department of Gastroenterology, Jilin City People's Hospital, from December 2019 to September 2021, among whom there were 23 patients in the ERCP+SpyGlass group and 19 patients in the PTGD+ERCP group. The two groups were compared in terms of the indicators such as surgical technical success, surgical operation time, surgical clinical success, postoperative recovery, length of hospital stay, and complications. The two-independent-samples t test was used for comparison of normally distributed continuous data between groups, and the Wilcoxon rank-sum test was used for comparison of non-normally distributed continuous data between groups; the chi- square test or the Fisher's exact test was used for comparison of categorical data between groups. Results Compared with the PTGD+ERCP group, the ERCP+SpyGlass group had a significant reduction in C-reactive protein after surgery ( Z =2.999, P =0.003). There were no significant differences between the two groups in technical success rate ( χ 2 =1.735, P =0.188), clinical success rate ( χ 2 =0.846, P =0.358), total time of operation ( t =1.667, P = 0.113), white blood cell count on day 1 after surgery ( t =1.075, P = 0.289), length of postoperative hospital stay ( t =1.560, P =0.127), and incidence rate of complications (all P > 0.05). Conclusion In the treatment of acute cholecystitis secondary to choledocholithiasis, the ERCP+SpyGlass system has a comparable clinical effect to PTGD+ERCP and is safe and effective, without increasing surgery-related adverse events and risks, and it can also solve the problems of the biliary tract and the gallbladder at one time through natural orifices, with no scars on body surface and convenient postoperative nursing. Therefore, it holds promise for clinical application.