A distributed relative navigation approach via inter-satellite sensing and communication for satellite clusters is proposed. The inter-satellite link(ISL)is used for ranging and exchanging data for the relative naviga...A distributed relative navigation approach via inter-satellite sensing and communication for satellite clusters is proposed. The inter-satellite link(ISL)is used for ranging and exchanging data for the relative navigation,which can improve the autonomy of the satellite cluster. The ISL topology design problem is formulated as a multi-objective optimization problem where the energy consumption and the navigation performance are considered. Further,the relative navigation is performed in a distributed fashion,where each satellite in the cluster makes observations and communicates with its neighbors via the ISL locally such that the transmission consumption and the computational complexity for the navigation are reduced. The ISL topology optimization problem is solved via the NSGA-Ⅱ algorithm,and the consensus Kalman filter is used for the distributed relative navigation. The proposed approach is flexible to varying tasks,with satellites joining or leaving the cluster anytime,and is robust to the failure of an individual satellite. Numerical simulations are presented to verify the feasibility of the proposed approach.展开更多
Objective： Hepatic progenitor cell transplantation has shed light on the treatment of liver failure. The present study was designed to evaluate whether xenogeneic liver epithelial progenitor cells （LEPCs） transplan...Objective： Hepatic progenitor cell transplantation has shed light on the treatment of liver failure. The present study was designed to evaluate whether xenogeneic liver epithelial progenitor cells （LEPCs） transplantation could promote liver recovery in a rat model of acute liver failure. The engraftment and hepatocytic differentiation of transplanted hepatic progenitor cells in the rat spleen was also investigated. Methods： LEPCs were propagated in vitro for long and transduced with lentiviral vector carrying mCherry gene. Intraperitoneal injection of CC14 followed by 2/3 partial hepatectomy three days later were used to establish rat models of acute liver failure. Rats were intrasplenically injected with mCherry modified LEPCs （n=20, 1× 107 cells/0.5 mL） or the same volume of medium （n=20）. Serum liver enzymes （ALT, AST） and liver histology were evaluated for 21 days after transplantation. The engraftment of transplanted LEPCs in the spleens was tested by polymerase chain reaction （PCR） amplification targeting mCherry gene. The differentiation into hepatocytic lineage of transplanted LEPCs was investigated usingimmunohistochemistry staining against Alb. Results： LEPCs were effectively transduced with lentiviral vector showing a transduction efficiency of 90%. Compared with control, cell-injected group displayed significantly lower levels of ALT and AST （P〈0.05） and better histological features including less swelling change and hepatocyte death. PCR amplification of mCherry sequences confirmed the engraftment of LEPCs in the spleens. Alb-positive cells first appeared 5 days after cell transplantation and the number of Alb-positive cells increased substantially （P〈0.05）, which revealed the hepatocytic differentiation process Conclusion： Xenogeneic hepatic progenitor cells can engraft and differentiate into hepatocytes in the splenic parenchyma. Intrasplenic delivery of hepatic progenitor cells ameliorates CCh/partial hepatectomy-induced liver injury in rats展开更多
In this paper, we define a model of random dynamical systems（RDS） on graphs and prove that they are actually homogeneous discrete-time Markov chains. Moreover, a necessary and sufficient condition is obtained for th...In this paper, we define a model of random dynamical systems（RDS） on graphs and prove that they are actually homogeneous discrete-time Markov chains. Moreover, a necessary and sufficient condition is obtained for that two state vectors can communicate with each other in a random dynamical system（tLDS）.展开更多
基金supported by the National Natural Science Foundation of China(No.61801213)。
文摘A distributed relative navigation approach via inter-satellite sensing and communication for satellite clusters is proposed. The inter-satellite link(ISL)is used for ranging and exchanging data for the relative navigation,which can improve the autonomy of the satellite cluster. The ISL topology design problem is formulated as a multi-objective optimization problem where the energy consumption and the navigation performance are considered. Further,the relative navigation is performed in a distributed fashion,where each satellite in the cluster makes observations and communicates with its neighbors via the ISL locally such that the transmission consumption and the computational complexity for the navigation are reduced. The ISL topology optimization problem is solved via the NSGA-Ⅱ algorithm,and the consensus Kalman filter is used for the distributed relative navigation. The proposed approach is flexible to varying tasks,with satellites joining or leaving the cluster anytime,and is robust to the failure of an individual satellite. Numerical simulations are presented to verify the feasibility of the proposed approach.
基金Supported by the National Natural Science Foundation of China(30600575,30830099)
文摘Objective： Hepatic progenitor cell transplantation has shed light on the treatment of liver failure. The present study was designed to evaluate whether xenogeneic liver epithelial progenitor cells （LEPCs） transplantation could promote liver recovery in a rat model of acute liver failure. The engraftment and hepatocytic differentiation of transplanted hepatic progenitor cells in the rat spleen was also investigated. Methods： LEPCs were propagated in vitro for long and transduced with lentiviral vector carrying mCherry gene. Intraperitoneal injection of CC14 followed by 2/3 partial hepatectomy three days later were used to establish rat models of acute liver failure. Rats were intrasplenically injected with mCherry modified LEPCs （n=20, 1× 107 cells/0.5 mL） or the same volume of medium （n=20）. Serum liver enzymes （ALT, AST） and liver histology were evaluated for 21 days after transplantation. The engraftment of transplanted LEPCs in the spleens was tested by polymerase chain reaction （PCR） amplification targeting mCherry gene. The differentiation into hepatocytic lineage of transplanted LEPCs was investigated usingimmunohistochemistry staining against Alb. Results： LEPCs were effectively transduced with lentiviral vector showing a transduction efficiency of 90%. Compared with control, cell-injected group displayed significantly lower levels of ALT and AST （P〈0.05） and better histological features including less swelling change and hepatocyte death. PCR amplification of mCherry sequences confirmed the engraftment of LEPCs in the spleens. Alb-positive cells first appeared 5 days after cell transplantation and the number of Alb-positive cells increased substantially （P〈0.05）, which revealed the hepatocytic differentiation process Conclusion： Xenogeneic hepatic progenitor cells can engraft and differentiate into hepatocytes in the splenic parenchyma. Intrasplenic delivery of hepatic progenitor cells ameliorates CCh/partial hepatectomy-induced liver injury in rats
基金Foundation item： Supported by the Science Foundation of Donghua University
文摘In this paper, we define a model of random dynamical systems（RDS） on graphs and prove that they are actually homogeneous discrete-time Markov chains. Moreover, a necessary and sufficient condition is obtained for that two state vectors can communicate with each other in a random dynamical system（tLDS）.
