A high-fidelity DNA unidirection synthesis method:preliminary exploration / 军事医学

Objective To establish a simple but quick method to improve the high fidelity of the synthesis of DNA frag -ments.Methods High fidelity DNA unidirection synthesis method (HFUS) was presented and used that involved Phusion DNA polymerase, BsrDⅠrestriction enzymes and λexonuclease.Using the same system at different temperatures , HFUS method synthesized one positive single-strand DNA and several reverse single -stranded DNA one by one into the target DNA fragment.Results Two random sequences DNA fragments of 340 bp and 450 bp were synthesized using HFUS meth-od.Conclusion This article explores a new method for the synthesis of genes .Through the harvest of 450 bp DNA, HFUS may promise to be a new approach to the synthesis of DNA .

The sample entropy and its application in EEG based epilepsy detection / 生物医学工程学杂志

It is of great importance for the detection of epilepsy in clinical applications. Based on the limitations of the common used approximate entropy (ApEn) in the epilepsy detection, this paper analyzes epileptic EEG signals with the sample entropy (SampEn) approach, a new method for signal analysis with much higher precision than that of the ApEn. Data analysis results show that the values from both ApEn and SampEn decrease significantly when the epilepsy is burst. Furthermore, the SampEn is more sensitive to EEG changes caused by the epilepsy, about 15%-20% higher than the results of the ApEn.

High Performance Liquid Chromatographic Separation ofLactic acid Enantiomer Using Chiral Mobile Phase Additives / 分析化学

The enantiomeric resolution of lactic acid was studied by reversed high performance liquid chromatography. β-cyclodextrin (β-CD), dimethyl (DM) and TM-β-CD were used as chiral mobile phase additives. The effects of different mobile phase, pH and concentration of chiral mobile phase additives on resolution of D,L-lactic acid were investigated. The results showed: the enantioselectivity of TM-β-CD was better than those of β-CD and DM-β-CD. D,L-lactic acid could be partly separated by DM-β-CD 　and could not be separated by β-CD, while it could be fully separated by TM-β-CD. As the concentration of TM-β-CD changed from 0.20　mmol/L to 1.00　mmol/L, The resolution varied slightly. The experiment of the effect of pH of mobile phase on Rs showed: as pH changed from 2.4 to 3.0, the Rs remain stable, and when pH＞3.1, the Rs decreased with the increase of pH. The RSD of retention time of L-lactic acid and D-lactic acid were 0.2% and 0.2%, respectively. The chromatographic systems with a dynamically-generated stationary phase with 2,3,6-tri-O-methyl-β-cyclodextrin proved to be an effective method for lactic acid enantiomer separation