Investigation on the application of teaching technology of virtual simulation in undergraduate schools of stomatology in China / 口腔疾病防治

Objective@#To investigate the current situation of using virtual simulation technology in undergraduate schools of stomatology in China, analyze the problems and put forward corresponding improvement suggestions. @*Methods@# A questionnaire survey was conducted among 672 teachers and 3 849 students in undergraduate schools of stomatology in China. @*Results @#25.81% of all participants had took part in dental virtual simulation courses, and 37.80% of the participants from “Double First-Class” universities had participated in dental virtual simulation courses. 92.12% of the virtual simulation courses were established for undergraduates. "Traditional course + virtual simulation model demonstration" is the main teaching form of virtual simulation courses. Most of the participants were satisfied with the virtual simulation courses offered by their schools. At present, there are also some deficiencies in the virtual simulation courses, such as lack of teaching resources, insufficient interaction and simulation.@*Conclusion@#There is difference in the application of virtual simulation technology in undergraduate schools of stomatology in China. The virtual simulation technology is more widely used in "Double First-Class" universities than in ordinary universities. Undergraduates are the main teaching objects of virtual simulation courses. Stomatological schools in China should pay attention to the development and utilization of virtual simulation curriculum resources by cooperation, enrich the form of virtual simulation courses and strengthen the promotion and application of virtual simulation technology in stomatological education.

A nonspecific primer anchored PCR technique for chromosome walking

A chromosome walking method was improved in this work. The new method was named as nonspecific primer anchored PCR (NPA-PCR). Nested gene specific primers were designed based on the known region and long random primer using degeneracy oligonucleotides for nonspecific anchoring. Annealing temperatures were varied to control the priming. Target sequences were obtained by PCR with random primer and gene-specific primer. Nonspecific sequence with long random primers at both ends formed stem loop structure due to inverted terminal repeats. The method was employed to isolate a gene with newly-isolated actinomycin producing strain Streptomyces setonii Z-L-22. A 0.77 kb fragment of actinomycin synthetase gene cluster was isolated from the strain. The fragments of 1474bp and 701bp were obtained, respectively, at the up and down streams of known fragment through the this method. NCBI Blast analysis showed that the walking sequence and the known sequence were located conjointly in the same cluster gene. It demonstrated that the result was correct and this technique could be useful and efficient for chromosome walking or isolating the gene.