BACKGROUND:The surroundings stimulation,such as wound and chemical injury,will result in changes of hair follicle stem cells(HFSC).Up to date,few articles indicate the effecl of burn on HFSCs.OBJECTIVE:To investigate the changes of β-nerve growth factor(β-NGF)level in vibrissa follicle bulge region and its effect on the healing of neonatal rats.METHODS:A total of 30 neonatal rats were selected to prepare burn models by giving 90℃ boiled tap water for 3 seconds,and vibrissa follicle bulge was separated at 12,24,36,48 and 60 hours pOsloperatiVeIy.The remained 6 neonatal rats were served as controls.Total protein concentration was measured by Brandford method The expression of β-NGF was detected by ELISA.Meanwhile the tissues in each time points were collected for frozen section and immunohistochemistry.RESULTS AND CONCLUSION:Among the tested total protein.the expression of the β-NGF increased after 36 hours.reached a peak at 60 hours after burn.The identical changes were found in tissue slices.The image analysis demonstrated that the β-NGF protein detection was coincident with β-NGF expression in tissues During 12 hours to 60 hours after burn,the expression of the β-NGF in the bulge area peaked at 60 hours;simultaneously,the repairing effect of healing also reached a peak.Bulge area is a nest of HFSC,the enhanced expression of β-NGF may have some positive significance to the differentiation of the HFSC and tissue repair.

Objective To explore the value of implementing PBL teaching method through the application of the virtual and simulative teaching platform in the teaching of "physical diagnostics". Methods The students majoring in clinical medicine were divided into experimental group (162 students) and control group (168 students) randomly. PBL teaching method through the application of the virtual and simulative teaching platform was used in the experimental group while the conventional teaching method was used in the control group. The effect of teaching was evaluated by questionnaire and examination and the data were analyzed through Chi-square and t-test. Result Questionnaire survey of satisfaction for the course showed that 92.6％ students (150 students) in experimental group were interested in the new course, 84.6％ students (137 students) felt it could increase the learning interest, and 91.3％ students (148 students) thought it could consolidate the clinical thinking. Statistical difference was found in average score between experiment group and control group in the PBL case analysis assessment examination in the course of"physical diagnostics" [(26.1±5.6) vs. (21.6±4.3), P<0.05]. Conclusion The introduction of virtual and simulative teaching plat-form in the teaching can help students understand truly all kinds of cases in clinical practice and improve the immediacy of teaching and students' initiatives, which is of great significance to the cultivation of students' clinical practice ability and clinical comprehensive thinking skills.