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“中等收入陷阱”及其跨越的门槛条件:一个内生技术进步解释 被引量:4
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作者 李海明 卢昀 伯莉红 《西南大学学报(社会科学版)》 CSSCI 北大核心 2019年第4期72-79,共8页
按照广为流行的世界银行分类标准,我国目前正面临“中等收入陷阱”的挑战.不过这一概念还需要理论上的澄清.把资本积累外部性引入经典索洛模型,通过内生技术进步来解释我国经济持续增长以及“中等收入陷阱”形成的作用机理.论文构建ARIM... 按照广为流行的世界银行分类标准,我国目前正面临“中等收入陷阱”的挑战.不过这一概念还需要理论上的澄清.把资本积累外部性引入经典索洛模型,通过内生技术进步来解释我国经济持续增长以及“中等收入陷阱”形成的作用机理.论文构建ARIMA模型,对我国跨越“中等收入陷阱”所需要的人均产出和资本正外部性程度进行预测分析.研究发现,技术进步机制下资本存量投入始终表现为经济正外部性,并且对经济增长的作用不断显著.而要想打破“中等收入陷阱”这种均衡状态,人均国内生产总值必须超过中等偏上收入水平的门槛,经济才可能向收敛于高收入水平方向运动.研究表明,通过更好地发挥资本积累外部性作用,有希望在未来五年或稍长时段跨越“中等收入陷阱”. 展开更多
关键词 索洛模型 “中等收入陷阱” 资本积累外部性 ARIMA模型
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In vitro induced dopaminergic differentiation of expanded rat mesencephalic neural stem cell
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作者 ZHENGMin WANGDongmei +5 位作者 JIAOWenchang lihaiming ZHAOLianxu BAIChixian WANGYaping PEIXuetao 《Chinese Science Bulletin》 SCIE EI CAS 2003年第16期1759-1763,共5页
Neural stem cell (NSC) is the progenitor of the neural system with the character of self-renew and hav-ing the potential to differentiate into all the phenotypes in the central nervous system (CNS). NSC may serve as a... Neural stem cell (NSC) is the progenitor of the neural system with the character of self-renew and hav-ing the potential to differentiate into all the phenotypes in the central nervous system (CNS). NSC may serve as a source of cell transplantation for the treatment of neurodegenerative diseases to replace degenerative neurons. In this study, NSCs derived from E12.5 rat mesencephalon were main-tained and expanded using a serum-free defined medium containing basic fibroblast growth factor (bFGF) and epi-dermal growth factor (EGF). While proliferating, the cells were immunoreactive for nestin and remained multipotent to generate neurons, astrocytes, and oligodendrocytes. After 15 times passage the total number of the cell expanded about 2.4×104 fold. Compared with untreated cultures, ascorbic acid (AA) treatment led to more dopaminergic (DAergic) differentitiation as indicated by the expression of tyrosine hydroxylase (TH). With the concentration increasing, more TH+ neurons were obtained. 100 mmol/L AA could lead to a increase more than 20-fold, and a concentration of 10 靘ol/L could lead to nearly 5-fold increase in TH+ cells. However, the ratio of TH+ cells was not improved any longer with the AA increasing above the concentration of 100 靘ol/L. The results demonstrate that expanded NSCs can be induced to differentiate into dopamine neurons in vitro, which can pro-vide enough cell population for the cell transplantation, as a main intervention for the neurodegenerative diseases such as Parkinson抯 disease. 展开更多
关键词 中脑神经系统 神经干细胞 NSC 中心神经系统 神经元 纤维原细胞 表皮生长因素 多巴胺 细胞分化 老鼠
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