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Virtual experiments teaching has been characterized by openness, interactivity and re-source sharing. It efficiently improves the experiments teaching effects and promotes the teaching reform. At present the virtual experiment systems used by domestic universities can realize simulation of the ex-perimental principle, apparatus, object, operation and data. In the virtual experiment system students deepen the understanding of the experiments through foregrounding and the networked virtual experiment manage-ment effectively improves the effects of experiments teaching through behind-the-scenes action.
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Objective To explore the effect of melatonin(MT) on the behavior of rats treated with noise stress and the related bio-mechanism. Methods Fifty rats were randomly divided into a blank group,two experimental groups and two control groups. The blank group was untreated. The experimental and control groups were exposed to 120dB noise stress for 1 day or 3 days, 8 hours per day, and treated with 15 mg/kg melatonin by intraperitoneal injection,or the same volume of physiological saline 30 minutes before noise stress. After noise stress,the rats' behavior was measured by open field test, learning and memory ability of rats was investigated with the method of Morris water maze and then nitric oxide (NO), superoxide dismutase (SOD) and malondialdehyde (MDA) contents in cerebral cortex and hippocampus of the rats were measured by TBA and Griess method respectively. Results No matter noise stress time was 1 day or 3 days, the excitability and explorative behavior of the 2 experimental groups(total movement distance (TMD) (1322.50 ± 504.32) cm, (1819.55 ± 458.37) cm, faster movement time (FMT) (68.49 ± 23.90) s, (87.34 ± 16.01) s, distance to center (DTC) (63.56 ± 2. 75) cm, (60. 13 ±1.87)cm, inner toriod time(ITT) (7.87 ±2.06)s,(9.60 ±2.89)s) in the open field test decreased significantly compared with those of the control group (TMD (2042.03 ± 449. 19) cm, (2325.73 ± 384.90) cm,FMT (109.32 ±21.84)s,(124.65 ± 16.74)s, DTC (58.00± 1.53)cm,(55.05 ±5.13)cm, ITT (12.84 ±3.62) s, (14.92 ± 2.75) s, P ＜ 0. 05, P ＜ 0.01);the escape latency of the experimental groups (( 10. 69 ±3.37) s, (18.87 ± 4.74) s) in Morris water maze was significantly shorter than that of the control group (( 23.86± 7.66)s, (33.55 ± 7.20)s, P＜ 0.05, P＜0.01). The contents of NO or MDA in cerebral cortex and hippocampus of the experimental groups (NO in cerebral cortex (3.35 ± 0.40) μmol/gprot, (4.50 ± 0.41) μmol/gprot, NO in hippocampus (2.24 ±0.18) μmol/gprot,(3.15 ±0.21) μmol/gprot, MDA in cerebral cortex(1.34 ±0.44)nmol/mgprot, (2.39 ± 0. 18) nmol/mgprot, MDA in hippocampus (0. 13 ± 0. 07) nmol/mgprot, (0.53 ± 0. 10)nmol/mgprot) were lower than those of the control group (NO in cerebral cortex (3.35 ± 0. 40) μmol/mgprot,(5.03 ± 0.44)μmol/mgprot, NO in hippocampus (2.93 ± 0. 31) μmol/gprot, (3.38 ± 0.24) μmol/gprot, MDA in cerebral cortex (2.24 ± 0.26) nmol/mgprot, (4.21 ± 0.21) nmol/mgprot, MDA in hippocampus (0.47 ± 0.29)nmol/mgprot, (1.33 ± 0. 187) nmol/mgprot, P ＜ 0.05, P ＜ 0. 01) respectively and the contents of SOD in cerebral cortex and hippocampus of the experimental groups (in cerebral cortex (763.95 ± 214.36) U/mgprot, (491.33 ±35.85) U/mgprot, in hippocampus (817.02 ± 232.39) U/mgprot, (644.85 ± 28.02) U/mgprot) were higher than those of the control group(in cerebral cortex (556.50 ± 101.51) U/mgprot, (327.35 ± 30.54) U/mgprot, in hippocampus (279.74 ± 117.02) U/mgprot, (108.75 ± 15.52) U/mgprot, P ＜ 0.05, P＜ 0.01) respectively. Conclusion Melatonin is effective in improving the ability of learning and memory in the rats of noise stress,possibly by inhibiting the increase of NO and MDA and increasing the SOD activity in cerebral cortex and hippocampus of the rats.
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AIM: To identify and quantitative analysis gentiopicroside content in the extract of Violent gentian of Tibetan herbal medicine. METHODS: Application of HPLC-the electricity sprays fog-mass spectroscopy/mass spectroscopy(HPLC-ESI-MS/MS) and the technique of LC-DAD-UV,by contrast with the reservation time of the authentic gentiopicroside,the ultraviolet absorbed spectrum,the molecule~+,quickly identified the gentiopicroside in the extract of violent gentian.As to it's quantitative analyis we adopted the capillary HPLC methods,with the weight of authentic gentiopicroside for abscissa. RESULTS: MS showed that the methanol extract of violet gentian mainly had five peaks.the compound structure of first peak was gentiopicroside,molecule~+ 356.9,result showed that gentiopicroside in gentian was 1.97%. CONCLUSION: Gentiopicroside is the mainly component of violet Gentia.