In this paper,we aim to unlock the potential of intelligent reflecting surfaces(IRSs)in cognitive internet of things(loT).Considering that the secondary IoT devices send messages to the secondary access point(SAP)by s...In this paper,we aim to unlock the potential of intelligent reflecting surfaces(IRSs)in cognitive internet of things(loT).Considering that the secondary IoT devices send messages to the secondary access point(SAP)by sharing the spectrum with the primary network,the interference is introduced by the IoT devices to the primary access point(PAP)which profits from the IoT devices by pricing the interference power charged by them.A practical path loss model is adopted such that the IRSs deployed between the IoT devices and SAP serve as diffuse scatterers,but each reflected signal can be aligned with its own desired direction.Moreover,two transmission policies of the secondary network are investigated without/with a successive interference cancellation(SIC)technique.The signal-to-interference plus noise ratio(SINR)balancing is considered to overcome the nearfar effect of the IoT devices so as to allocate the resource fairly among them.We propose a Stackelberg game strategy to characterize the interaction between primary and secondary networks.For the proposed game,the Stackelberg equilibrium is analytically derived to optimally obtain the closed-form solution of the power allocation and interference pricing.Numerical results are demonstrated to validate the performance of the theoretical derivations.展开更多
This study investigated the potential application of a zirconium oxide （ZrO2） ceramic foam culturing system to the production of glial cell line-derived neurotrophic factor （GDNF）. Three sets of ZrO2 ceramic foams...This study investigated the potential application of a zirconium oxide （ZrO2） ceramic foam culturing system to the production of glial cell line-derived neurotrophic factor （GDNF）. Three sets of ZrO2 ceramic foams with different pore densities of 10, 20, and 30 pores per linear inch （PPI） were prepared to support a 3D culturing system. After primary astrocytes were cultured in these systems, production yields of GDNF were evaluated. The biomaterial bio- compatibility, cell proliferation and activation of cellular signaling pathways in GDNF synthesis and secretion in the culturing systems were also assessed and compared with a conventional culturing system. In this study, we found that the ZrO2 ceramic foam culturing system was biocompatible, using which the GDNF yields were elevated and sustained by stimulated cell proliferation and activation of signaling pathways in astrocytes cultured in the system. In conclusion, the ZrO2 ceramic foam is promising for the development of a GDNF mass production device for Parkinson＇s disease treatment.展开更多
We report here a cocrystal with artesunate as the active pharmaceutical ingredient(API)and a pharmaceutical intermediate 4,4?-bipyridine as the cocrystal former(CCF).The analysis of single-crystal X-ray diffraction de...We report here a cocrystal with artesunate as the active pharmaceutical ingredient(API)and a pharmaceutical intermediate 4,4?-bipyridine as the cocrystal former(CCF).The analysis of single-crystal X-ray diffraction demonstrates that the eutectic structural unit consists of two artesunate molecules and one 4,4?-bipyridine molecule with their ratio to be 2:1.The carboxyl group on artesunate acts as a donor,and the acceptor is N on 4,4?-bipyridine,forming an O–H···N hydrogen bond.The appearance of new diffraction peaks in the X-ray powder diffraction pattern also indicates the formation of new phases.The PXRD results indicated a pure phase for the synthesized sample.The cocrystal is slightly soluble in water.Antimicrobial activities showed that the cocrystal displayed effective inhibition of different bacteria.展开更多
This work investigates the potential of the aerial intelligent reflecting surface(AIRS)in secure communication,where an intelligent reflecting surface(IRS)carried by an unmanned aerial vehicle(UAV)is utilized to help ...This work investigates the potential of the aerial intelligent reflecting surface(AIRS)in secure communication,where an intelligent reflecting surface(IRS)carried by an unmanned aerial vehicle(UAV)is utilized to help the communication between the ground nodes.Specifically,we formulate the joint design of the AIRS’s deployment and the phase shift to maximize the secrecy rate.To solve the non-convex objective,we develop an alternating optimization(AO)approach,where the phase shift optimization is solved by the Riemannian manifold optimization(RMO)method,while the deployment optimization is handled by the successive convex approximation(SCA)technique.Furthermore,to reduce the computational complexity of the RMO method,an element-wise block coordinate descent(EBCD)based method is employed.Simulation results verify the effect of AIRS in improving the communication security,as well as the importance of designing the deployment and phase shift properly.展开更多
基金This work was supported by the U.K.Engineering and Physical Sciences Research Council under Grants EP/P008402/2 and EP/R001588/1.
文摘In this paper,we aim to unlock the potential of intelligent reflecting surfaces(IRSs)in cognitive internet of things(loT).Considering that the secondary IoT devices send messages to the secondary access point(SAP)by sharing the spectrum with the primary network,the interference is introduced by the IoT devices to the primary access point(PAP)which profits from the IoT devices by pricing the interference power charged by them.A practical path loss model is adopted such that the IRSs deployed between the IoT devices and SAP serve as diffuse scatterers,but each reflected signal can be aligned with its own desired direction.Moreover,two transmission policies of the secondary network are investigated without/with a successive interference cancellation(SIC)technique.The signal-to-interference plus noise ratio(SINR)balancing is considered to overcome the nearfar effect of the IoT devices so as to allocate the resource fairly among them.We propose a Stackelberg game strategy to characterize the interaction between primary and secondary networks.For the proposed game,the Stackelberg equilibrium is analytically derived to optimally obtain the closed-form solution of the power allocation and interference pricing.Numerical results are demonstrated to validate the performance of the theoretical derivations.
基金Project supported by the National Natural Science Foundation of China(Nos.81171262 and 81371473)
文摘This study investigated the potential application of a zirconium oxide （ZrO2） ceramic foam culturing system to the production of glial cell line-derived neurotrophic factor （GDNF）. Three sets of ZrO2 ceramic foams with different pore densities of 10, 20, and 30 pores per linear inch （PPI） were prepared to support a 3D culturing system. After primary astrocytes were cultured in these systems, production yields of GDNF were evaluated. The biomaterial bio- compatibility, cell proliferation and activation of cellular signaling pathways in GDNF synthesis and secretion in the culturing systems were also assessed and compared with a conventional culturing system. In this study, we found that the ZrO2 ceramic foam culturing system was biocompatible, using which the GDNF yields were elevated and sustained by stimulated cell proliferation and activation of signaling pathways in astrocytes cultured in the system. In conclusion, the ZrO2 ceramic foam is promising for the development of a GDNF mass production device for Parkinson＇s disease treatment.
基金supported by the National Natural Science Foundation of China(No.21861005)the Foundation of Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(CMEMR2018-C15 and CMEMR2016-A11)。
文摘We report here a cocrystal with artesunate as the active pharmaceutical ingredient(API)and a pharmaceutical intermediate 4,4?-bipyridine as the cocrystal former(CCF).The analysis of single-crystal X-ray diffraction demonstrates that the eutectic structural unit consists of two artesunate molecules and one 4,4?-bipyridine molecule with their ratio to be 2:1.The carboxyl group on artesunate acts as a donor,and the acceptor is N on 4,4?-bipyridine,forming an O–H···N hydrogen bond.The appearance of new diffraction peaks in the X-ray powder diffraction pattern also indicates the formation of new phases.The PXRD results indicated a pure phase for the synthesized sample.The cocrystal is slightly soluble in water.Antimicrobial activities showed that the cocrystal displayed effective inhibition of different bacteria.
基金supported in part by the National Natural Science Foundation of China(Nos.61901490,61801434,62071223,and 62031012)the Open Fund of the Shaanxi Key Laboratory of Information Communication Network and Security(No.ICNS201801)+1 种基金the Project funded by China Postdoctoral Science Foundation(No.2020M682345)the Henan Postdoctoral Foundation(No.202001015).
文摘This work investigates the potential of the aerial intelligent reflecting surface(AIRS)in secure communication,where an intelligent reflecting surface(IRS)carried by an unmanned aerial vehicle(UAV)is utilized to help the communication between the ground nodes.Specifically,we formulate the joint design of the AIRS’s deployment and the phase shift to maximize the secrecy rate.To solve the non-convex objective,we develop an alternating optimization(AO)approach,where the phase shift optimization is solved by the Riemannian manifold optimization(RMO)method,while the deployment optimization is handled by the successive convex approximation(SCA)technique.Furthermore,to reduce the computational complexity of the RMO method,an element-wise block coordinate descent(EBCD)based method is employed.Simulation results verify the effect of AIRS in improving the communication security,as well as the importance of designing the deployment and phase shift properly.
