随着电网换相型高压直流输电(line commutated converter based high voltage direct current, LCC-HVDC)技术的广泛应用,交直流混联电力系统的交互稳定性问题日益突出。首先基于状态空间平均法建立了考虑非线性换相重叠动态过程的LCC...随着电网换相型高压直流输电(line commutated converter based high voltage direct current, LCC-HVDC)技术的广泛应用,交直流混联电力系统的交互稳定性问题日益突出。首先基于状态空间平均法建立了考虑非线性换相重叠动态过程的LCC换流器传递函数模型。为适应愈加复杂的直流输电系统建模,提出利用模块化思想分别建立LCC-HVDC各子系统小信号模型,并推导了能反映交直流系统和换流器之间电气耦合特性的接口矩阵实现子系统连接,从而模块化建立精确且易于扩展的计及控制链路延时和锁相环输出相位波动的双端LCC-HVDC系统改进小信号模型。最后分析了控制系统参数和控制链路延时对系统小干扰稳定性的影响以及失稳模态的主导因素,揭示了双端LCC-HVDC系统交直流混合谐振机理及送受端交互影响具体过程。研究结果可以为系统参数设计、谐振抑制措施提供理论基础。展开更多
Objective To investigate the regulatory relationship of Protein Phosphatase 2 Regulatory Subunit B"Alpha(PPP2R3A)and hexokinase 1(HK1)in glycolysis of hepatocellular carcinoma(HCC).Methods In HepG2 and Huh7 cells...Objective To investigate the regulatory relationship of Protein Phosphatase 2 Regulatory Subunit B"Alpha(PPP2R3A)and hexokinase 1(HK1)in glycolysis of hepatocellular carcinoma(HCC).Methods In HepG2 and Huh7 cells,PPP2R3A expression was silenced by small interfering RNA(siRNA)and overexpression by plasmid transfection.The PPP2R3A-related genes were searched by RNA sequencing.Glycolysis levels were measured by glucose uptake and lactate production.QRT-PCR,ELISA,western blot and immunofluorescence assay were performed to detect the changes of PPP2R3A and HK1.Cell proliferation,migration and invasion assay were used to study the roles of HK1 regulation by PPP2R3A.Results RNA sequencing data revealed that PPP2R3A siRNA significantly downregulated the expression of HK1.PPP2R3A gene overexpression promotes,while gene silencing suppresses,the level of HK1 and glycolysis in HCC cells.In HCC tissue samples,PPP2R3A and HK1 were colocalized in the cytoplasm,and their expression showed a positive correlation.HK1 inhibition abrogated the promotion of glycolysis,proliferation,migration and invasion by PPP2R3A overexpression in liver cancer cells.Conclusion Our findings showed the correlation of PPP2R3A and HK1 in the glycolysis of HCC,which reveals a new mechanism for the oncogenic roles of PPP2R3A in cancer.展开更多
文摘随着电网换相型高压直流输电(line commutated converter based high voltage direct current, LCC-HVDC)技术的广泛应用,交直流混联电力系统的交互稳定性问题日益突出。首先基于状态空间平均法建立了考虑非线性换相重叠动态过程的LCC换流器传递函数模型。为适应愈加复杂的直流输电系统建模,提出利用模块化思想分别建立LCC-HVDC各子系统小信号模型,并推导了能反映交直流系统和换流器之间电气耦合特性的接口矩阵实现子系统连接,从而模块化建立精确且易于扩展的计及控制链路延时和锁相环输出相位波动的双端LCC-HVDC系统改进小信号模型。最后分析了控制系统参数和控制链路延时对系统小干扰稳定性的影响以及失稳模态的主导因素,揭示了双端LCC-HVDC系统交直流混合谐振机理及送受端交互影响具体过程。研究结果可以为系统参数设计、谐振抑制措施提供理论基础。
基金supported by National Natural Science Foundation of China [81372595]
文摘Objective To investigate the regulatory relationship of Protein Phosphatase 2 Regulatory Subunit B"Alpha(PPP2R3A)and hexokinase 1(HK1)in glycolysis of hepatocellular carcinoma(HCC).Methods In HepG2 and Huh7 cells,PPP2R3A expression was silenced by small interfering RNA(siRNA)and overexpression by plasmid transfection.The PPP2R3A-related genes were searched by RNA sequencing.Glycolysis levels were measured by glucose uptake and lactate production.QRT-PCR,ELISA,western blot and immunofluorescence assay were performed to detect the changes of PPP2R3A and HK1.Cell proliferation,migration and invasion assay were used to study the roles of HK1 regulation by PPP2R3A.Results RNA sequencing data revealed that PPP2R3A siRNA significantly downregulated the expression of HK1.PPP2R3A gene overexpression promotes,while gene silencing suppresses,the level of HK1 and glycolysis in HCC cells.In HCC tissue samples,PPP2R3A and HK1 were colocalized in the cytoplasm,and their expression showed a positive correlation.HK1 inhibition abrogated the promotion of glycolysis,proliferation,migration and invasion by PPP2R3A overexpression in liver cancer cells.Conclusion Our findings showed the correlation of PPP2R3A and HK1 in the glycolysis of HCC,which reveals a new mechanism for the oncogenic roles of PPP2R3A in cancer.
