To improve accuracy and efficiency in power systems dynamic modeling,the distributed online modeling approach is a good option.In this approach,the power system is divided into sub-grids,and the dynamic models of the ...To improve accuracy and efficiency in power systems dynamic modeling,the distributed online modeling approach is a good option.In this approach,the power system is divided into sub-grids,and the dynamic models of the sub-grids are built independently within the distributed modeling system.The subgrid models are subsequently merged,after which the dynamic model of the whole power system is finally constructed online.The merging of the networks plays an important role in the distributed online dynamic modeling of power systems.An efficient multi-area networks-merging model that can rapidly match the boundary power flow is proposed in this paper.The iterations of the boundary matching during network merging are eliminated due to the introduction of the merging model,and the dynamic models of the sub-grid can be directly“plugged in”with each other.The results of the calculations performed in a real power system demonstrate the accuracy of the integrated model under both steady and transient states.展开更多
Liver tumor-initiating cells(T-ICs) are thought to be inherently resistant to the cytotoxic effects of chemotherapy, and can self-renewal and maintain tumor-initiating potential. Therefore, effective anticancer resear...Liver tumor-initiating cells(T-ICs) are thought to be inherently resistant to the cytotoxic effects of chemotherapy, and can self-renewal and maintain tumor-initiating potential. Therefore, effective anticancer research strategies should target the unique properties of T-ICs. In this study, we found that metformin, a first-line drug of choice for the treatment of type 2 diabetes, inhibited liver T-ICs both in vivo and in vitro. Metformin inhibited the formation of hepatospheres and epithelial-specific antigen-positive(ESA,CD133?) cell colonies by hepatocellular carcinoma(HCC)cell lines. Metformin also downregulated the expression of several T-IC-related genes which are involved in the signaling pathways, governing the self-renewal, proliferation and differentiation of T-ICs. Furthermore, the targeting of liver T-ICs by metformin was PI-3-kinase-Akt-mTOR(PI3K/Akt/mTOR)-pathway dependent. The PI3K/Akt/mTOR inhibitor LY294002 and rapamycin abolished the inhibitory effect of metformin on CD133?cells, and the PI3K/Akt/mTOR stimulator EGF promoted the inhibitory effect of metformin on CD133?cells. Metformin also dramatically decreased the tumor volume and number of CD133 expressing tumor cells in a xenograft mouse model. Metformin exerted a synergistic effect with cisplatin to target both T-ICs and non-T-ICs, and resulted in the smallest tumor volume and lowest number of CD133 expressing tumor cells. This study indicates that the antidiabetic drug metformin could potentially be used in combination therapy with chemotherapeutic agents to improve the treatment of liver cancer.展开更多
基金This work was supported by the National Key Basic Research Program of China(973 Program)(2013CB228204)the National Natural Science Foundation of China(51137002,51190102,51407060).
文摘To improve accuracy and efficiency in power systems dynamic modeling,the distributed online modeling approach is a good option.In this approach,the power system is divided into sub-grids,and the dynamic models of the sub-grids are built independently within the distributed modeling system.The subgrid models are subsequently merged,after which the dynamic model of the whole power system is finally constructed online.The merging of the networks plays an important role in the distributed online dynamic modeling of power systems.An efficient multi-area networks-merging model that can rapidly match the boundary power flow is proposed in this paper.The iterations of the boundary matching during network merging are eliminated due to the introduction of the merging model,and the dynamic models of the sub-grid can be directly“plugged in”with each other.The results of the calculations performed in a real power system demonstrate the accuracy of the integrated model under both steady and transient states.
基金supported by the National Natural Science Foundation of China(81172285)
文摘Liver tumor-initiating cells(T-ICs) are thought to be inherently resistant to the cytotoxic effects of chemotherapy, and can self-renewal and maintain tumor-initiating potential. Therefore, effective anticancer research strategies should target the unique properties of T-ICs. In this study, we found that metformin, a first-line drug of choice for the treatment of type 2 diabetes, inhibited liver T-ICs both in vivo and in vitro. Metformin inhibited the formation of hepatospheres and epithelial-specific antigen-positive(ESA,CD133?) cell colonies by hepatocellular carcinoma(HCC)cell lines. Metformin also downregulated the expression of several T-IC-related genes which are involved in the signaling pathways, governing the self-renewal, proliferation and differentiation of T-ICs. Furthermore, the targeting of liver T-ICs by metformin was PI-3-kinase-Akt-mTOR(PI3K/Akt/mTOR)-pathway dependent. The PI3K/Akt/mTOR inhibitor LY294002 and rapamycin abolished the inhibitory effect of metformin on CD133?cells, and the PI3K/Akt/mTOR stimulator EGF promoted the inhibitory effect of metformin on CD133?cells. Metformin also dramatically decreased the tumor volume and number of CD133 expressing tumor cells in a xenograft mouse model. Metformin exerted a synergistic effect with cisplatin to target both T-ICs and non-T-ICs, and resulted in the smallest tumor volume and lowest number of CD133 expressing tumor cells. This study indicates that the antidiabetic drug metformin could potentially be used in combination therapy with chemotherapeutic agents to improve the treatment of liver cancer.
