ABSTRACT
A microbial fuel cell (MFC)-based microbial electrochemical sensor was developed for real-time on-line monitoring of heavy metals in water environment. The microbial electrochemical sensor was constructed with staggered flow distribution method to optimize the parameters such as external resistance value and external circulation rate. The inhibition of concentration of simulated heavy metal wastewater on voltage under optimal parameters was analyzed. The results showed that the best performance of MFC electrochemical sensor was achieved when the external resistance value was 130 Ω and the external circulation rate was 1.0 mL/min. In this case, the microbial electrochemical sensors were responsive to 1-10 mg/L Cu2+, 0.25-1.25 mg/L Cd2+, 0.25-1.25 mg/L Cr6+ and 0.25-1.00 mg/L Hg2+ within 60 minutes. The maximum rejection rates of the output voltage were 92.95%, 73.11%, 82.76% and 75.80%, respectively, and the linear correlation coefficients were all greater than 0.95. In addition, the microbial electrochemical sensor showed a good biological reproducibility. The good performance for detecting heavy metals by the newly developed microbial electrochemical sensor may facilitate the real-time on-line monitoring of heavy metals in water environment.
Subject(s)
Bioelectric Energy Sources , Electrodes , Metals, Heavy/analysis , Reproducibility of Results , Wastewater , WaterABSTRACT
Objective To investigate the curative effect of mammotome minimally invasive operation in the treatment of benign breast disease and analyse its characteristics.Methods Two hundred and five cases of benign breast disease patients admitted to the hospital in time sequence were divided into the observation group (105 cases) and control group(100 cases).Observation group used mammotome minimally invasive rotary cutting operation,and the control group used conventional breast tumor resection.The surgical results of two groups of patients,tumor complete resection or not,whether the patients for surgery satisfaction were observed.Patients of two groups were compared with intraoperative and postoperative relevant indicators,and the postoperative complications.Results In the observation group,105 patients with mammotome spiral cutting knife surgery of breast masses were completely resected,the satisfaction of patients for surgery was 96.2％ (101/ 105),significantly higher than that of control group(81.0％ (81/100),x2 =4.187,P＜0.05).The operative time,blood loss,length of incision values of observation group were significantly lower than those in the control group((17.30±6.70) min vs (57.23 ± 8.96) min,(10.43 ± 5.14) ml vs (109.16 ± 13.45) ml,(10.27 ±0.06) cm vs (1.43±0.12) cm;t=18.741,26.167,11.421;P＜0.05),the postoperative recovery time and the scar length were significantly lower than the control group((4.1±2.5) d vs (8.0±3.5) d,(0.15±0.03) cm vs (1.21±0.46) cm;t =5.176,2.647;P＜0.05),breast deformation cases,tumor residual proporation were 1.9％(2/105) and 0(0/105),fewer than that in the control group(12.0％(12/100),9.0％(9/100);x2=6.721,11.470;P＜0.05).In control group breast deformation subcutaneous hematoma and ecchymosis,wound infection,skin damage,pain,pigment calm incidence were 2.9％ (3/105),5.7％ (6/105),1.9％ (2/105),2.9％(3/105),8.6％(9/105),2.9％(3/105),significantly lower than those in the observation group(9.0％(9/100),12.0(12/100),7.0％ (7/100),16.0％(16/100),23.0％(23/100),8.0％(8/100);x2 =2.164,3.071,2.467,6.194,6.177,2.642;P＜ 0.05).Conclusion Mammotome minimally invasive rotary cut scalpel compare with conventional breast tumor excision undoubtedly has a more significant curative effect and patient satisfaction and have the characteristics of operation safety,efficiency,beautiful,fewer complications,humanized.