【目的】基于聚合酶链式反应—变性梯度凝胶电泳(PCR-DGGE)对桑树根、茎、叶组织内生菌多样性的分析,结合浓度、纯度、PCR扩增性等指标,比较4种DNA提取方法之优劣。【方法】采用常见的DNA提取方法十六烷基三甲基溴化铵(CTAB)法、缓冲液振荡(SPBS)法、液氮研磨(LNG)法和试剂盒(KIT)法提取桑树各组织DNA,从PCR-DGGE多样性等多方面对4种方法进行比较。【结果】对于桑树根和茎,DNA提取浓度最高的方法是LNG法,最低的是SPBS法;桑树叶情况则完全相反。桑树各组织,KIT法获得的DNA纯度均最高。桑树各组织通过16S r DNA PCR-DGGE比较内生细菌多样性,适宜的DNA提取方法是LNG法或CTAB法,不宜采用KIT法提取DNA。内生真菌ITS PCR-DGGE分析结果完全不同,最佳提取方法是KIT法,最不适宜的DNA提取方法因组织不同而异。【结论】对于桑树内生菌研究,最佳的DNA提取方法因组织不同而异,还与研究的内生菌种类有关系。
Objective:Acupuncture is an efficient treatment modality for many different training,but the technique can be challenging to master.Identification of the different acupuncture points can now be practiced in a standardized and patient-safe simulation-based environment.We aim to gather additional evidence regarding simulation-based training of acupuncture skills and hope that the simulation-based test developed and will be used for simulation-based mastery learning in future develop.Methods:The aim of this study was to develop a test of acupuncture skills using the TCM(Traditional Chinese Medicine) Meridians & Acupoints Anatomy Teaching Platform and gather validity evidence using Messick’s framework.Novice medical students without prior experience in acupuncture(n=43),intermediate medical students who had finished the mandatory acupuncture course(n=24),and skilled acupuncture doctors(n=17) were included in the study.One-hundred and seven acupuncture points were presented to the participants in identical randomized order and they were asked to identify each point by touching the correct anatomical location on the simulator.The simulator automatically registered the accuracy of participants’ answers.Results:The reliability of the final test(66 acupuncture points) was at a high level with a Cronbach’s alpha of 0.98 and only 16 acupuncture points were needed to ensure a reliability of 0.90.The test could discriminate significantly between all three groups and a credible pass/fail-score of 34 points was determined which resulted in eight out of 43(19%) novices passing the test and only two out of 17(12%)experienced failing the test.These consequences were statistically significant(P <0.001).Conclusion:Based on Messick’s framework we demonstrated strong validity evidence for a newly developed simulation-based test of acupuncture points localization skills.The test can be used as an aid to decide when trainees are ready to progress to more advanced training and clinical practice.Compared with the traditional point
