A novel biosensor for aflatoxin B1 detecting has been reported. The biosensor electrode for AFB1 detecting was assembled by immobilized aflatoxin-oxidoreductase using open-ended multi-walled carbon nanotubes as matrix. Its linear range was between 0.16μM and 3.2μM. And if the specific anti-aflatoxin B1 antibody and aflatoxin oxidoreductase were both immobilized on the electrode with Multi-Walled carbon nanotubes, the detection limit of the modified electrode could be 16 nM with a 10 times improved sensitivity. The aflatoxin enzyme biosensor assembled this way strode one step forward its practical application.

Objective:To discuss the safety and effectiveness of del Nido cardioplegia solution in severe valvular surgery.Methods:A retrospective analysis of 138 patients of severe valvular disease underwent valve replacement or valvuloplasty in Hunan Provincial People′s Hospital between July 2019 and December 2020 was performed. According to the different cardioplegic solution used, patients were separated in two groups: the del Nido cardioplegia group (D group, n=73) and the St. Thomas cardioplegia group (C group, n=65). The perioperative clinical results of the two groups were compared to evaluate the safety and effectiveness of del Nido cardioplegia in the operation of severe valvular disease. Results:Preoperative characteristics were similar between the two groups, including gender, age, body weight, ejection fraction, and myocardial markers ( P>0.05). No statistical differences were noted in cardiopulmonary bypass time, clamp time, mechanical ventilation time, vasoactive drug use time, ICU and hospital stay time, and ejection fraction before discharge ( P>0.05). However, the times of cardioplegia perfusion [(1.33±0.47)times vs (4.08±0.48)times] and the total perfusion time [(3.96±1.41)min vs (13.15±1.46)min] in group D were lower than those in group C, while the automatic rebound rate (90.41% vs 76.92%) was higher than that in group C ( P<0.05). Both groups successfully completed the operation. There were no serious complications of important organs such as low cardiac output, brain, liver and kidney during and after the operation. There were no deaths during hospitalization, and all patients were cured and discharged. Conclusions:There was no significant difference in myocardial protection between del Nido and St. Thomas cardioplegia solution in severe valvular surgery. The application of del Nido cardioplegia could reduce the frequency of perfusions and total perfusion time.

Objective:To investigate the clinical significance of autologous platelet separation (APS) in different time courses of cardiovascular surgery.Methods:The relevant data of 75 patients with cardiovascular surgery from September 2019 to August 2021 in Hunan Provincial Peoples′ Hospital were collected retrospectively. They were divided into two groups according to whether APS was used during the operation: group A used APS (37 cases) and group B did not use APS (38 cases). The two groups were divided into subgroups according to the length of cardiopulmonary bypass (CPB): A1 and B1 were medium and short-term groups (CPB bypass time ≤200 min), and A2 and B2 were long-term groups (CPB bypass time >200 min). Blood routine, postoperative drainage volume, postoperative blood product infusion volume and thromboelastogram at different time points were recorded and compared.Results:The postoperative drainage volume, red blood cell infusion volume and ventilator assisted time in group A were less than those in group B (all P<0.05); The postoperative drainage volume [(645.79±205.25)ml vs (886.67±360.96)ml, P=0.006], erythrocyte infusion volume [(3.24±2.53)U vs (4.77±1.97)U, P=0.016], platelet infusion volume [0.00(0.00, 0.00)U vs 1.00(0.125, 2.00)U, P=0.002] and thromboelastogram coagulation reaction time [(7.38±1.74)min vs (9.09±3.57)min, P=0.047] in group A2 were significantly better than those in group B2 (all P<0.05); There were no significant difference in the above indexes between A1 and B1 group (all P>0.05). Conclusions:APS can improve the coagulation function of patients undergoing cardiopulmonary bypass and reduce the amount of bleeding and blood products. Its protective effect is more prominent in high-risk cardiovascular surgery with long cardiopulmonary bypass and complex operation.