The present study established a rat model of global cerebral ischemia induced by chest compression for six minutes to dynamically observe expressional changes of three glutamate transporters in the cerebral cortex and...The present study established a rat model of global cerebral ischemia induced by chest compression for six minutes to dynamically observe expressional changes of three glutamate transporters in the cerebral cortex and hippocampus. After 24 hours of ischemia, expression of glutamate transporter-1 significantly decreased in the cerebral cortex and hippocampus, which was accompanied by neuronal necrosis. At 7 days post-ischemia, expression of excitatory amino acid carrier 1 decreased in the hippocampal CA1 region and cortex, and was accompanied by apoptosis Expression of glutamate-aspartate transporter remained unchanged at 6 hours 7 days after ischemia. These results suggested that glutamate transporter levels were altered at different periods of cerebral ischemia.展开更多
Small-scale rotorcraft unmanned robotic systems(SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relati...Small-scale rotorcraft unmanned robotic systems(SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relative research in the future. In the past decade, aerial manipulation of SRURSs has attracted the interest of researchers globally. This paper provides a literature review of the last 10 years(2008–2017) on SRURSs, and details achievements and challenges. Firstly, the definition, current state, development, classification, and challenges of SRURSs are introduced. Then, related papers are organized into two topical categories: mechanical structure design, and modeling and control. Following this, research groups involved in SRURS research and their major achievements are summarized and classified in the form of tables. The research groups are introduced in detail from seven parts. Finally, trends and challenges are compiled and presented to serve as a resource for researchers interested in aerial manipulation of SRURSs. The problem,trends, and challenges are described from three aspects. Conclusions of the paper are presented,and the future of SRURSs is discussed to enable further research interests.展开更多
Using province-level data in China for the period of 1999-2015,we examine the mechanisms through which sectoral differences in leverage ratio and productivity affect macro leverage ratios.The state-owned sector undert...Using province-level data in China for the period of 1999-2015,we examine the mechanisms through which sectoral differences in leverage ratio and productivity affect macro leverage ratios.The state-owned sector undertakes a large number of public services and plays an irreplaceable role in solving market failures and providing public goods.However,in the case of information asymmetry and incentive incompatibility,these policy burdens affect the leverage optimization and productivity improvement of the state-owned sector.From the perspective of sectoral differences,we therefore decompose the change in macro leverage ratio into leverage ratio structure effect and productivity structure effect,and then substantiate the impact mechanisms of these two effects on macro leverage ratios.Overall,our conclusions provide theoretical support and empirical evidence for structural deleveraging in China.展开更多
基金supported by the National Natural Science Foundation of China, No. 81171168Shanghai Science and Technology Committee, No. 10140903200
文摘The present study established a rat model of global cerebral ischemia induced by chest compression for six minutes to dynamically observe expressional changes of three glutamate transporters in the cerebral cortex and hippocampus. After 24 hours of ischemia, expression of glutamate transporter-1 significantly decreased in the cerebral cortex and hippocampus, which was accompanied by neuronal necrosis. At 7 days post-ischemia, expression of excitatory amino acid carrier 1 decreased in the hippocampal CA1 region and cortex, and was accompanied by apoptosis Expression of glutamate-aspartate transporter remained unchanged at 6 hours 7 days after ischemia. These results suggested that glutamate transporter levels were altered at different periods of cerebral ischemia.
基金supported by the National Natural Science Foundation of China (Nos. 91748201 and 51505014)
文摘Small-scale rotorcraft unmanned robotic systems(SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relative research in the future. In the past decade, aerial manipulation of SRURSs has attracted the interest of researchers globally. This paper provides a literature review of the last 10 years(2008–2017) on SRURSs, and details achievements and challenges. Firstly, the definition, current state, development, classification, and challenges of SRURSs are introduced. Then, related papers are organized into two topical categories: mechanical structure design, and modeling and control. Following this, research groups involved in SRURS research and their major achievements are summarized and classified in the form of tables. The research groups are introduced in detail from seven parts. Finally, trends and challenges are compiled and presented to serve as a resource for researchers interested in aerial manipulation of SRURSs. The problem,trends, and challenges are described from three aspects. Conclusions of the paper are presented,and the future of SRURSs is discussed to enable further research interests.
基金supported financially by the National Social Science Foundation of China(No.21FJYB005)the China Postdoctoral ScienceFoundation(No.2019M663758).
文摘Using province-level data in China for the period of 1999-2015,we examine the mechanisms through which sectoral differences in leverage ratio and productivity affect macro leverage ratios.The state-owned sector undertakes a large number of public services and plays an irreplaceable role in solving market failures and providing public goods.However,in the case of information asymmetry and incentive incompatibility,these policy burdens affect the leverage optimization and productivity improvement of the state-owned sector.From the perspective of sectoral differences,we therefore decompose the change in macro leverage ratio into leverage ratio structure effect and productivity structure effect,and then substantiate the impact mechanisms of these two effects on macro leverage ratios.Overall,our conclusions provide theoretical support and empirical evidence for structural deleveraging in China.
