Objective To evaluate the effect of carotid artery stenting combined with nimodipine on cerebral hemodynamics by comparing and analyzing the change of anterior cerebral blood flow before and after treatment through tr...Objective To evaluate the effect of carotid artery stenting combined with nimodipine on cerebral hemodynamics by comparing and analyzing the change of anterior cerebral blood flow before and after treatment through transcrania Doppler （TCD）. Methods Twenty patients with ischemic cerebrovascnlar disease were detected in blood flow velocity of bilateral middle cerebral arteries （MCA） and anterior cerebral arteries （ACA） and artery pulsatility index with TCD before and two weeks after treatment. Results After treatment, TCD examination showed dynamic changes in blood flow significantly, lpsilateral MCA flow velocity significantly increased; ipsilateral ACA flow velocity did not change significantly; there was no significant increase in the contralateral MCA flow velocity; flow rate decreased significantly in contralateral ACA. Conclusion Carotid artery stenting combined with nimodipine treatment can cause anterior cerebral hemodynamic changes in ipsilateral hemisphere and significantly improve blood flow展开更多
Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish ...Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish kinetics. Much effort is needed to exploit high-performance electrode materials to satisfy the reversible capacity of PIBs. In this paper, nano Sb confined in N-doped carbon fibers(Sb@CN nanofibers)were successfully prepared through an electrospinning method, which was designed to improve potassium storage performances. Sb@CN nanofibers benefit from the fact that the synergy between the porous nanofiber frame structure and the uniformly distributed Sb nano-components in the carbon matrix can effectively accelerate the ion migration rate and reduce the mechanical stress caused by K+insertion/extraction, Sb@CN nanofiber electrodes thus exhibited excellent potassium storage performance, especially long cycle stability, as expected. When utilized as a PIB anode, they delivered high reversible capacity of 360.2 m Ah g-1 after 200 cycles at 50 m A g-1, and a particularly stable capacity of 212.7 m Ah g-1 was also obtained after 1000 cycles even at 5000 m A g-1. Given such outstanding electrochemical performances,this work is expected to provide insight into the development and exploration of advanced alloy-type electrodes for PIBs.展开更多
The pursuit of high-mileage models results in the recurrence of lithium metal batteries(LMBs)to researchers’horizon.However,the lithium(Li)metal anode for LMBs undergoes the uncontrollable formation of Li dendrites a...The pursuit of high-mileage models results in the recurrence of lithium metal batteries(LMBs)to researchers’horizon.However,the lithium(Li)metal anode for LMBs undergoes the uncontrollable formation of Li dendrites and infinite volume change during cycling,impeding its practical application.To overcome these challenges,we developed a metal-organic framework(MOF)-derived pathway to construct lithiophilic three-dimensional(3D)skeleton using different substrates(e.g.,carbon cloth(CC)and Cu mesh)for dendrite-free lithium metal anodes.As a typical example,the MOF-derived ZnO/nitrogen-doped carbon(NC)nanosheet-modified 3D CC was well-constructed as a lithiophilic hierarchical host(CC@ZnO/NC@Li)for molten Li infiltration.Benefiting from the lithiophilic N-functional groups and LiZn alloy,the synthesized CC@ZnO/NC@Li composite anode promoted the uniform distribution of Li,resulting in a dendrite-free morphology.Meanwhile,the 3D conductive carbon skeleton enhanced the reaction kinetics and buffered the volume change of the electrode.The CC@ZnO/NC@Li composite anode presented a prolonged lifespan of over 1000 cycles at 5 mA cm^(−2) with a low overpotential of 19 mV.Coupled with a LiFePO_(4) cathode,the CC@ZnO/NC@Li composite anode also exhibited superior electrochemical properties in the full-cell system.This versatile strategy may open up the channel of designing multi-functional lithiophilic 3D hosts for the Li metal anode.展开更多
基金Supported by the Shaanxi Scientific and Technical Plan(2009K18-02)
文摘Objective To evaluate the effect of carotid artery stenting combined with nimodipine on cerebral hemodynamics by comparing and analyzing the change of anterior cerebral blood flow before and after treatment through transcrania Doppler （TCD）. Methods Twenty patients with ischemic cerebrovascnlar disease were detected in blood flow velocity of bilateral middle cerebral arteries （MCA） and anterior cerebral arteries （ACA） and artery pulsatility index with TCD before and two weeks after treatment. Results After treatment, TCD examination showed dynamic changes in blood flow significantly, lpsilateral MCA flow velocity significantly increased; ipsilateral ACA flow velocity did not change significantly; there was no significant increase in the contralateral MCA flow velocity; flow rate decreased significantly in contralateral ACA. Conclusion Carotid artery stenting combined with nimodipine treatment can cause anterior cerebral hemodynamic changes in ipsilateral hemisphere and significantly improve blood flow
基金supported by the National Natural Science Foundation of China(51904342,51622406,and 21673298)the National Postdoctoral Program for Innovative Talents(BX201600192)+4 种基金Central South University Postdoctoral Foundation(140050018)China Postdoctoral Science Foundation(2017 M6203552)the National Key Research and Development Program of China(2017YFB0102000,2018YFB0104200)Hunan Provincial Science and Technology Plan(2017TP1001)the Fundamental Research Funds for the Central Universities of Central South University(2019zzts431,2019zzts433)。
文摘Antimony-based materials with high theoretical capacity are known as promising anodes for potassiumion batteries(PIBs). However, they still face challenges from the large ionic radius of the K ion, which has sluggish kinetics. Much effort is needed to exploit high-performance electrode materials to satisfy the reversible capacity of PIBs. In this paper, nano Sb confined in N-doped carbon fibers(Sb@CN nanofibers)were successfully prepared through an electrospinning method, which was designed to improve potassium storage performances. Sb@CN nanofibers benefit from the fact that the synergy between the porous nanofiber frame structure and the uniformly distributed Sb nano-components in the carbon matrix can effectively accelerate the ion migration rate and reduce the mechanical stress caused by K+insertion/extraction, Sb@CN nanofiber electrodes thus exhibited excellent potassium storage performance, especially long cycle stability, as expected. When utilized as a PIB anode, they delivered high reversible capacity of 360.2 m Ah g-1 after 200 cycles at 50 m A g-1, and a particularly stable capacity of 212.7 m Ah g-1 was also obtained after 1000 cycles even at 5000 m A g-1. Given such outstanding electrochemical performances,this work is expected to provide insight into the development and exploration of advanced alloy-type electrodes for PIBs.
基金supported by the National Natural Science Foundation of China(51771076 and 51621001)Guangdong"Pearl River Talents Plan"(2017GC010218)+1 种基金the R&D Program in Key Areas of Guangdong Province(2020B0101030005)Guangdong Basic and Applied Basic Research Foundation(2020B1515120049)。
文摘The pursuit of high-mileage models results in the recurrence of lithium metal batteries(LMBs)to researchers’horizon.However,the lithium(Li)metal anode for LMBs undergoes the uncontrollable formation of Li dendrites and infinite volume change during cycling,impeding its practical application.To overcome these challenges,we developed a metal-organic framework(MOF)-derived pathway to construct lithiophilic three-dimensional(3D)skeleton using different substrates(e.g.,carbon cloth(CC)and Cu mesh)for dendrite-free lithium metal anodes.As a typical example,the MOF-derived ZnO/nitrogen-doped carbon(NC)nanosheet-modified 3D CC was well-constructed as a lithiophilic hierarchical host(CC@ZnO/NC@Li)for molten Li infiltration.Benefiting from the lithiophilic N-functional groups and LiZn alloy,the synthesized CC@ZnO/NC@Li composite anode promoted the uniform distribution of Li,resulting in a dendrite-free morphology.Meanwhile,the 3D conductive carbon skeleton enhanced the reaction kinetics and buffered the volume change of the electrode.The CC@ZnO/NC@Li composite anode presented a prolonged lifespan of over 1000 cycles at 5 mA cm^(−2) with a low overpotential of 19 mV.Coupled with a LiFePO_(4) cathode,the CC@ZnO/NC@Li composite anode also exhibited superior electrochemical properties in the full-cell system.This versatile strategy may open up the channel of designing multi-functional lithiophilic 3D hosts for the Li metal anode.
