Objective A major component of flow cytometry data analysis involves gating , which is the process of identifying homogeneous groups of cells .As manual gating is error-prone, non-reproducible, nonstandardized, and time-consuming , we propose a time-efficient and accurate approach to automated analysis of flow cytometry data .Methods Unlike manual analysis that successively gates the data projected onto a two-dimensional filed, this approach, using the K-means clustering results , directly analyzed multidimensional flow cytometry data via a similar subpopulations-merged algorithm.In order to apply the K-means to analysis of flow cytometric data , kernel density estimation for selecting the initial number of clustering and k-d tree for optimizing efficiency were proposed .After K-means clustering , results closest to the true populations could be achieved via a two-segment line regression algorithm .Results The misclassification rate (MR) was 0.0736 and time was 2 s in Experiment One, but was 0.0805 and 1 s respectively in Experiment Two. Conclusion The approach we proposed is capable of a rapid and direct analysis of the multidimensional flow cytometry data with a lower misclassification rate compared to both nonprobabilistic and probabilistic clustering methods .

Objective To present a miniaturized nucleic acid amplification system for spot rapid detection .Methods A miniaturized nucleic acid amplification system with structured packed porous media of particles to uniform the air temperature was designed according to the working principle and heat transfer characteristics of an air -heated nucleic acid amplification system.Thermodynamic simulation and temperature cycling test were carried on to verify the feasibility of the system.Results The structured packed porous media of particles worked well in uniforming the air temperature of the system and the temperature uniformity could reach 0.8℃.The miniaturized nucleic acid amplification system with a volume parameter of 80 mm ×40 mm ×20 mm(length ×height ×width)was portable.The average rate of heating was 10℃/s while the average rate of cooling was 5℃/s.Compared with standard PCR instrument , the miniaturized nucleic acid amplification system performed well in the process of amplification and met the requirements of preliminary design .Conclusion The miniaturized nucleic acid amplification system with a rapid reaction velocity and portable volume could be applied to nucleic acid detection of unknown samples on the spot .

Objective To explore the relationship between the spot size and the result of ploidy analysis in the detection technology based on single-particles, and to fix the scope of spot thickness on the basis of the experimental result.Methods The influence of spot thickness on voltage signals produced by single cells was analyzed.The parameters of the beam shap system in the incident field were designed and optimized on ZEMAX.Finally, according to the cells′diameter, the target size of spots was set.A set of spots of different thickness and of Gaussian distribution obtained from the optical experimental platform was used to conduct ploidy detection experiments.Results Target spots were both obtained from ZEMAX simulation and the optical platform.When the spot thickness was larger than both monocytes and coenocytes, the mean fluorescence intensity ratio was 2.03,which met the demand of the index.Conclusion When the height of the pulse is used to represent the fluorescence density, the relative size of spots and cells will affect the result of ploidy detection.Only when spot thickness is larger than cells is the ploidy ratio accurate.

Objective A comparability analysis was performed between the various parameters of the self-developed dry-type blood cell analyzer with the reference instrument (Sysmex XT-1800i).Methods In line with the evaluation program of blood cells issued by ICSH,the detection results,six parameters as HCT,Hb,GRAN (granulocytes),LM (lymphatic and monocytes),WBC and PLT,were compared between the two instruments.Some indexes of the subject instrument such as precision,comparability,outlier points,bias,etc.were analyzed and compared so as to calculate the equation of linear regression and the expected bias intervals.Results The intra and inter CV of the subject instrument about six parameters were respectively less than 5％ and 6％,so it showed that the instrument had good precision.Correlation analysis showed that the classification results of HCT,Hb,GRAN and WBC had a good correlation (r =0.991,0.972,0.986,0.975,P ＜0.01),while that of LM and PLT were slightly lower (r =0.952,0.942,P ＜0.01) ; As to the medical decision level,HCT values were 14％ and 70％,WBC 0.5 × 109/L and 3 ×109/L,and PLT 10 × 109/L,50 × 109/L and 100 × 109/L,and the acceptable bias of these values all fell in the confidence intervals; the values of the rest items were slightly higher than the high value of the confidence interval of expected bias.Conclusions The subject instrument produces the same results in the test of its parameters as the reference instrument Sysmex XT-1800i and therefore the two instruments are comparable.The subject instrument is particularly suitable for field rapid detection.

Objective To explore the effect and mechanism of superficial vein puncture for the first time in obese children auxiliary with venous enhancement.Methods From January 201 5 to July 201 5,1 20 children (3 -7 years old)with obesity were randomly divided into control group and observation group,60 cases in each group.The control group used conventional methods to select limbs superficial vein puncture,the observation group guided by visualizer to select limbs superficial vein puncture.Results The superficial vein puncture success rate of observation group was 96.67% for the first time,the puncture time was (78.95 ±6.68)s;Success rate of control group was 78.33%,the puncture time was (98.44 ±34.1 3)s,the differences between two groups were statistically significant (χ2 =1 0.385,t =21 .787,all P <0.05).Conclusion Obese children with venous visualizer superficial vein punc-ture success rate increased significantly,for the first time the puncture time shortened.