特质焦虑大学生对中性刺激的预测偏向

目的:本研究探讨特质焦虑大学生对中性刺激是否存在预测偏向现象;同时,考察特质焦虑对中性刺激预测偏向的影响。方法:采用改进的预测偏向实验,用中性刺激作为材料,采用特质-状态焦虑量表筛选出高特质焦虑和低特质焦虑各20人,比较其在100%可预测、50%可预测和不可预测三种情境下的皮电反应。结果:全部被试对中性刺激产生了预测偏向;与低特质焦虑大学生相比,高特质焦虑大学生在不可预测情境下的皮电反应显著地升高。结论:即使刺激是中性,不可预测情境也能诱发高特质焦虑个体明显的预测偏向。     

转化生长因子β和脑源性神经营养因子联合诱导成年大鼠骨髓基质细胞向神经元样细胞的分化

BACKGROUND： It has been demonstrated that transforming growth factor-β （TGF-β） and brain- derived neurotrophic factor （BDNF） can induce stem cell differentiation into neuron-like cells. OBJECTIVE： To investigate the efficacy of TGF-β and BDNF at inducing the differentiation of adult rat bone marrow stromal cells （BMSCs） into neuron-like cells, both in combination or alone. DESIGN, TIME AND SETTING： A comparative observation experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University between October 2007 and January 2008. MATERIALS： TGF-~ and BDNF were purchased from Sigma, USA; mouse anti-rat neuron specific enolase, neurofilament and glial fibrillary acidic protein were purchased from Beijing HMHL Biochem Ltd., China. METHODS： BMSCs were isolated from rats aged 4 weeks and incubated with TGF-β（1μ g/L） and/or BDNF （50 μ g/mL）. MAIN OUTCOME MEASURES： Expression of neuron-specific enolase, neurofilament and glial fibrillary acidic protein were determined by immunocytochemistry. RESULTS： BMSCs differentiated into neuron-like cells following induction of TGF-β and BDNF, and expressed both neuron-specific enolase and neurofilament. The percent of positive cells was significantly greater in the combination group than those induced with TGF-β or BDNF alone （P 〈 0.01）. CONCLUSION： Treatment of BMSCs with a combination of TGF-β and BDNF induced differentiation into neuron-like cells, with the induction being significantly greater than with TGF-β or BDNF alone.