AIM: To analyse monosaccharides of gynostema polysaccharide from Gynostemma pentaphyllum gathered from Pingli County,Shanxi Province and study the protecting effect of polysaccharide on plasmid DNA damage. METHODS: Gynostema polysaccharide was extracted with hot distilled water.After dialysis and deproteinization,polysaccharide in trifluoroacetic acid solution was hydrolyzed by 1-phenyl-3-methyl-5-pyrazolone,and then determined by HPLC.Tolerance of gynostema polysaccharide to the UV-photolysis of H_2O_2 was used to investigate the protecting effect. RESULTS: Polysaccharide consisted of mannose(Man),rhamnose(Rha),glucuronic acid(GlcUA),galacturonic acid(GalUA),glucose(Glc),galactose(Gal),xylose(Xyl) and arabonose(Ara).And it had the effect on protecting plasmid DNA from damage,showing a concentration dependent velationship. CONCLUSION: The method is simple and sensitive,the result is precise and believable.It provides scientific data for the use of Gynostemma pentaphyllum.

Object\ To establish a plantlet regeneration system of Rubus idaeus L for the purpose to obtain a large number of high quality seedling in a short time Methods\ Stem apex and part of the stem were used as the explant and the optimal culture media and conditions were selected by orthogonal design Results\ An optimum culture medium for the induction of callus, adventitious bud and root was obtained which can be carried out in the laboratory with comparative ease and good repeatability Conclusion\ A basic medium + BA 0 2 mg/L+NAA 1 0～1 5 mg/L was most suitable for the induction of callus; a medium + BA 1 mg/L+NAA 0 1～0 2 mg/L+GA 3 6～8 mg/L+CH 300 mg/L was good for the induction of bud; a medium +BA 1 mg/L+NAA 0 1 mg/L+GA 3 2 mg/L was suitable for propagation of the bud; and the basic medium+IBA 0 1 mg/L+NAA 0 5 mg/L was good for the induction of root

Objective:To compare the application effects of high-definition two-dimensional (HD-2D) and glasses-free three-dimensional (GF-3D) display systems in thoracoscopy teaching.Methods:A total of 40 clinical medicine interns with no surgical experience from The First Affiliated Hospital of Guangzhou Medical University were recruited and were required to participate in a 1-week training course of endoscopy. They were then randomly allocated to the HD-2D group and GF-3D group and asked to perform three tasks: peg transfer, circular cutting, and suture knotting. Their performance was measured with a system that scored speed and precision. SPSS 25.0 was used to conduct t-test, Pearson Chi-square test and Fisher exact test for the comparison. Results:The mean time for the peg transfer test in GF-3D group was shorter than that in HD-2D group, without statistically significant difference [(63.20±21.11) s vs. (71.15± 17.26) s, P = 0.212]. The mean time for the circular cutting test in GF-3D group was shorter than that in HD-2D group, without statistically significant difference [(112.50±16.67) s vs. (118.15±24.43) s, P=0.410]. The mean time for the suture knotting test in GF-3D group was shorter than that in HD-2D group, with statistically significant difference [(301.50±32.77) s vs. (341.75±57.23) s, P=0.019]. The total score in GF-3D group was higher than that in HD-2D group, with statistically significant difference [(78.33±5.88) points vs. (72.08±6.83) points, P=0.005]. Conclusion:The GF-3D display system is clearly superior to the HD-2D system because it reduces the surgical learning curve, and is therefore suitable for basic teaching and skills training.