Objective: To evaluate the efficiency of an implanted chip system on blood pressure regulation. Methods: The mean arterial pressure (MAP) and heart rate (HR) were recorded in anesthetized rabbits. Based on the set poi...Objective: To evaluate the efficiency of an implanted chip system on blood pressure regulation. Methods: The mean arterial pressure (MAP) and heart rate (HR) were recorded in anesthetized rabbits. Based on the set point theory, an implanted chip system was designed to regulate the blood pressure by stimulating the aortic depressor nerve (ADN) according to the feedback of blood pressure. The blood pressure regulation induced by the implanted chip system was carried out twice (lasted for 15 min and 60 min respectively) and the change of MAP and HR during the regulation was compared with the control. Results: There was a significant decrease of MAP during the first regulation ([-32.0 ± 6.6] mmHg) and second regulation ([-27.4 ± 6.2] mmHg) compared with the control (P<0.01). The HR was also significantly decreased during regulation compared with the control. Both MAP and HR returned to the baseline immediately without rebound after the regulation ceased. Conclusion: The implanted chip system can regulate the blood pressure successfully and keep the blood pressure in a lower constant level without adaptation.展开更多
Microstructure evolution and dislocation configurations in nanostructured Al–Mg alloys processed by high pressure torsion （HPT） were analyzed by transmission electron microscopy （TEM） and high-resolution TEM （HR...Microstructure evolution and dislocation configurations in nanostructured Al–Mg alloys processed by high pressure torsion （HPT） were analyzed by transmission electron microscopy （TEM） and high-resolution TEM （HRTEM）. The results show that the grains less than 100 nm have sharp grain boundaries （GBs） and are completely free of dislocations. In contrast, a high density of dislocation as high as 1017 m^-2 exists within the grains larger than 200 nm and these larger grains are usually separated into subgrains and dislocation cells. The dislocations are 60° full dislocations with Burgers vectors of 1/2〈110〉and most of them appear as dipoles and loops. The microtwins and stacking faults （SFs） formed by the Shockley partials from the dissociation of both the 60° mixed dislocation and 0° screw dislocation in ultrafine grains were simultaneously observed by HRTEM in the HPT Al–Mg alloys. These results suggest that partial dislocation emissions, as well as the activation of partial dislocations could also become a deformation mechanism in ultrafine-grained aluminum during severe plastic deformation. The grain refinement mechanism associated with the very high local dislocation density, the dislocation cells and the non-equilibrium GBs, as well as the SFs and microtwins in the HPT Al-Mg alloys were proposed.展开更多
文摘Objective: To evaluate the efficiency of an implanted chip system on blood pressure regulation. Methods: The mean arterial pressure (MAP) and heart rate (HR) were recorded in anesthetized rabbits. Based on the set point theory, an implanted chip system was designed to regulate the blood pressure by stimulating the aortic depressor nerve (ADN) according to the feedback of blood pressure. The blood pressure regulation induced by the implanted chip system was carried out twice (lasted for 15 min and 60 min respectively) and the change of MAP and HR during the regulation was compared with the control. Results: There was a significant decrease of MAP during the first regulation ([-32.0 ± 6.6] mmHg) and second regulation ([-27.4 ± 6.2] mmHg) compared with the control (P<0.01). The HR was also significantly decreased during regulation compared with the control. Both MAP and HR returned to the baseline immediately without rebound after the regulation ceased. Conclusion: The implanted chip system can regulate the blood pressure successfully and keep the blood pressure in a lower constant level without adaptation.
基金Project(BK2012715)supported by the Basic Research Program(Natural Science Foundation)of Jiangsu Province,ChinaProject(14KJA430002)supported by the Key University Science Research Project of Jiangsu Province,China+3 种基金Project(50971087)supported by the National Natural Science Foundation of China,ChinaProjects(11JDG070,11JDG140)supported by the Senior Talent Research Foundation of Jiangsu University,ChinaProject(hsm1301)supported by the Foundation of the Jiangsu Province Key Laboratory of High-end Structural Materials,ChinaProject(Kjsmcx2011004)supported by the Foundation of the Jiangsu Province Key Laboratory of Materials Tribology,China
文摘Microstructure evolution and dislocation configurations in nanostructured Al–Mg alloys processed by high pressure torsion （HPT） were analyzed by transmission electron microscopy （TEM） and high-resolution TEM （HRTEM）. The results show that the grains less than 100 nm have sharp grain boundaries （GBs） and are completely free of dislocations. In contrast, a high density of dislocation as high as 1017 m^-2 exists within the grains larger than 200 nm and these larger grains are usually separated into subgrains and dislocation cells. The dislocations are 60° full dislocations with Burgers vectors of 1/2〈110〉and most of them appear as dipoles and loops. The microtwins and stacking faults （SFs） formed by the Shockley partials from the dissociation of both the 60° mixed dislocation and 0° screw dislocation in ultrafine grains were simultaneously observed by HRTEM in the HPT Al–Mg alloys. These results suggest that partial dislocation emissions, as well as the activation of partial dislocations could also become a deformation mechanism in ultrafine-grained aluminum during severe plastic deformation. The grain refinement mechanism associated with the very high local dislocation density, the dislocation cells and the non-equilibrium GBs, as well as the SFs and microtwins in the HPT Al-Mg alloys were proposed.
