To optimize the extraction technology of the total saponins in Dipsaci Radix, the extraction efficiency of total saponins was investigated with respecting to three variables including time, ethanol concentration and liquid-to-solid ratio. On the basis of a series of one-factor-at-a-time experiments, a polynomial regression model equation was fitted by the combined use of central composite experimental design and regression analysis. By analyzing the regression model using response surface analysis, the optimum extraction conditions of total saponins from Dipsaci Radix were identified as follows: 7 times of 55% alcohol, refluxing 3 times, 2.8 hours every time, and the extraction efficiency of total saponins was up to 0.201 1 g·g-1 and the asperosaponin Ⅵ was up to 0.015 4 g·g-1 under the optimized conditions. Confirmatory experiment indicated the good prediction ability of the established model and provided the basis for further development and utilization of Dipsaci Radix.

Objective To explore the efficacy of the case and scenario teaching method in the neurosurgery practice teaching.Methods By cluster sampling,153 nursing students underwent rotary practice in neurosurgery department in People's Hospital of Three Gorges University from September 2011 to July 2012 were trained with the case and scenario teaching method.Scenario simulation training combined with case playback teaching was used in practice teaching.At the end of the internship,nursing students' satisfaction was investigated and their operational capacity was evaluated.Self-designed questionnaire was adopted to evaluate satisfaction.Operational capacity evaluation scores of nursing students were divided into several parts:basic operation examination (30％),specialized operation (30％),professional theory (30％) and teacher evaluation (10％).Data were analyzed using Excel spreadsheet for entry.Countif and Count function formula were used to calculate eligibility and the passing rate.Results Nursing students had high evaluation on case playback teaching methods.By this method,153(100％) nursing students considered that the learning initiative was improved.At the end of the internship,passing rates of basic operation examination,specialized operation,professional theory were 98.69％ (151/153),96.73 ％ (148/153) and 100％ while the total passing rate was 100％.Conclusion The case and scenario teaching method could develop the study positivity and practice ability of nursing students and can enhance the internship efficacy.

Objective To construct lentiviral expression vector of rat IP3R1 gene,and identify its silencing effect by using PC12 cell lines. Methods Oligo DNA sequences of 4 pairs of miRNA,named as miRNA1,miRNA2,miRNA3 and miRNA4,were designed according to IP3R1 gene sequence (GenBank:NM_001007235). The single strand of oligo DNA was annealed to form double strand DNA,and then connected with the empty plasmid pcDNA TM 6.2-GW/EmGFP-miR. By using gateway technology,the expression vector pcDNA TM 6.2-GW/EmGFP-miR-IP3R1 was linked into lentiviral destination vector pLenti6/V5-DEST to form the lentiviral expression vector pLenti6/V5-DEST-IP3R1,then it was transformed into infectious lentiviral particles and to infect PC12 cell lines. Silencing effect of gene IP3R1 was detected by Real-time PCR and Western blot. Results The sequence of expression vector pcDNA TM 6.2-GW/EmGFP-miR-IP3R1 was proved correct using sequencing method. After the transfection of letivirus vector pLenti6/V5-DEST-IP3R1 into PC12 cell lines,the IP3R1 mRNA and protein level were down-regulated 48h later,of which miRNA2 and miRNA3 sequence showed the best silencing effect,and the expression of IP3R1 in the blank control and negative control showed no significant changes. Conclusions Lentiviral expression vector pLenti6/V5-DEST-IP3R1 was constructed successfully. pLenti6/V5-DEST-IP3R1 may render the IP3R1 expression in PC12 cell lines down-regulated,and it provides a foundation for studying the function of calcium release channel IP3R1.