ABSTRACT
A new method for O-ethyl S-[2-( diisopropylamino) ethyl] methylphosphonothiolate ( VX) , sarin detection and its kinetic analysis based on piezoresistive microcantilever aptasensor was developed, where VX, sarin aptamers were immobilized on the microcantilever surface by biotin-avidin binding system. A linear relationship between the response voltage and the concentration of VX in the range of 2-60μg/L was obtained. The linear regression equation was △Ue=0. 886C-1. 039 (n=5, R=0. 984, p<0. 001) and the detection limit was 2μg/L ( S/N≥3 ) . A linear relationship between the response voltage and the concentration of sarin in the range of 10-60 μg/L was obtained, the linear regression equation was △Ue=0. 716C-2. 304 ( n=5, R=0 . 996 , p<0 . 001 ) and the detection limit was 10 μg/L ( S/N≥3 ) . The sensor showed no response for O-butyl methylphosphonochloridate, a structural analog of VX and sarin, which indicated high specificity and good anti-interference ability. On this basis, a reaction kinetic model based on receptor-ligand binding and the relationship with output voltage change was established. Response voltage (△Ue ) and response time( t0 ) were obtained from the fitting equation on different concentrations of VX, sarin fitted well with the measured values.
ABSTRACT
A new magnetic affinity immunoassay (MAIA) strategy based on enzyme-labeled phage displayed antibody was developed. The assay consisted of a sandwich format in which immobilized polyclonal antibody (pcAb) on magnetic microparticle was used for capture probe, and enzyme-labeled phage displayed antibody for specific detection probe to increase enzyme amount and enhance detection signal. By the proposed method,β-bungarotoxin (β-BGT) was successfully detected. A linear relationship between absorbance value and the concentration of β-BGT in the range of 0. 016-62. 5 μg / L was obtained. The linear regression equation was Y=0. 641X+1. 355 (R =0. 9925, n = 13, p<0. 0001) with a detection limit of 0. 016 μg / L. In comparison with the traditional ELISA, this method gave a 10-fold better sensitivity in β-BGT detection. This strategy also gave a 4-fold better sensitivity comparing with the MAIA based on enzyme labeled monoclonal antibody (mcAb). Due to low detection limit, acceptable reproducibility and high specificity, this method holds great promise in toxin trace detection.
ABSTRACT
Objective To investigate the application effect of Problem based learning (PBL) combined with role play teaching method in the training of emergency internal medicine.Methods Totally 60 medical students were randomly divided into two groups.The students in the observation groop were trained with PBL teaching method while those in control group were trained with traditional teaching method.The practical performances of the students in both groups were evaluated by virtual experience of dealing with patients in the emergency department through the role play teaching method.The grasp of basic knowledge was assessed by writing tests.Finally all the students in the observation group answered a survey about the teaching methods.Results There was uo difference in the scores of the basic knowledge test between the two groups ( P ＞ 0.05 ).The practical ability of the observation group was much better than that of the control group in the role play practice ( P ＜ 0.05 ).Almost all the students in the observation group accept the PBL teaching method.Conelusion PBL combined with role play teaching method is effective based on the characteristics of emergency medicine.