Objective To identify the genetype of the PS1/APP double transgenie mouse model, then to analyse the histopathological changes in the brain and compare the differences between the transgenie mice models and Aβ1-40-in...Objective To identify the genetype of the PS1/APP double transgenie mouse model, then to analyse the histopathological changes in the brain and compare the differences between the transgenie mice models and Aβ1-40-injeeted rats models of Alzheimer disease. Methods The modified congo red staining, Nissl＇s staining and immunohistology staining was used to observe the Aβ deposits, activation of astrocyte respectively. Results ①The PS1/APP transgenic mouse extensively displayed Aβ deposits in the cortex and hippocampal structures, and GFAP positive cells were aggregated in mass and surrounded the congo red-positive plaque. ②The Aβ1-40-intrahippocmnpal-injeeted rat model showed the Aβ plaque deposits in the dentate gyrus of the hippocampus, with the astrocyte surrounded. The neurons loss was significant in the injection point and pin hole of injection with Nissl＇s staining methods. GFAP-positive cells increased significantly compared with the uninjected lateral of the hippocampus. Conclusion Although Aβ1-40-injected rat models could simulate some characteristic pathological features of human Alzheimer diseases, Aβ deposits and neurons loss in partial hippocampal, it would not simulate the progressive degenenration in the brain of AD. The double transgenie PS1/APP mice could simulate the specific pathogenesis and progressive changes of AD, mainly is Aβ deposits and the spongiocyte response , while no neurons loss were observed in this model.展开更多
Ultraviolet(UV) photodetectors based on wide band gap semiconductor have attracted much attention for their small volume, low working voltage, long lifetime, good chemical and thermal stability. Up to now, many resear...Ultraviolet(UV) photodetectors based on wide band gap semiconductor have attracted much attention for their small volume, low working voltage, long lifetime, good chemical and thermal stability. Up to now, many researches have been done on the semiconductors based UV detectors and some kinds of detectors have been made, such as metal–semiconductor–metal(MSM), Schottky, and PIN-type detectors. However, the sensitivity values of those detectors are still far from the expectation. Recent years, surface plasmon(SP) has been considered to be an effective way to enhance the sensitivity of semiconductor based UV photodetector. When the light is matched with the resonance frequency of surface plasmon, the localized field enhancement or scattering effect will happen and thus the spectral response will be enhanced.Here, we present an overview of surface plasmon enhancing the performance of UV detectors, including the GaN, ZnO,and other wide band gap semiconductor UV detectors. Both fundamental and experimental achievements are contained in this review.展开更多
A surface plasmon(SP)is a fundamental excitation state that exists in metal nanostructures.Over the past several years,the performance of optoelectronic devices has been improved greatly via the SP enhancement effect....A surface plasmon(SP)is a fundamental excitation state that exists in metal nanostructures.Over the past several years,the performance of optoelectronic devices has been improved greatly via the SP enhancement effect.In our previous work,the responsivity of GaN ultraviolet detectors was increased by over 30 times when using Ag nanoparticles.However,the physics of the SP enhancement effect has not been established definitely because of the lack of experimental evidence.To reveal the physical origin of this enhancement,Kelvin probe force microscopy(KPFM)was used to observe the SP-induced surface potential reduction in the vicinity of Ag nanoparticles on a GaN epilayer.Under ultraviolet illumination,the localized field enhancement induced by the SP forces the photogenerated electrons to drift close to the Ag nanoparticles,leading to a reduction of the surface potential around the Ag nanoparticles on the GaN epilayer.For an isolated Ag nanoparticle with a diameter of~200 nm,the distribution of the SP localized field is located within 60 nm of the boundary of the Ag nanoparticle.For a dimer of Ag nanoparticles,the localized field enhancement between the nanoparticles was the strongest.The results presented here provide direct experimental proof of the localized field enhancement.These results not only explain the high performance of GaN detectors observed with the use of Ag nanoparticles but also reveal the physical mechanism of SP enhancement in optoelectronic devices,which will help us further understand and improve the performance of SP-based optoelectronic devices in the future.展开更多
Commonly used energy storage devices include stacked layers of active materials on two-dimensional sheets,and the limited specific surface area restricts the further development of energy storage.Three-dimensional(3D)...Commonly used energy storage devices include stacked layers of active materials on two-dimensional sheets,and the limited specific surface area restricts the further development of energy storage.Three-dimensional(3D)structures with high specific surface areas would improve device performance.Herein,we present a novel procedure to fabricate macroscopic,high-quality,nitrogen-doped,3D graphene/nanoparticle aerogels.The procedure includes vacuum filtration,freeze-drying,and plasma treatment,which can be further expanded for large-scale production of nitrogen-doped,graphene-based aerogels.The behavior of the supercapacitor is investigated using a typical nitrogen-doped graphene/Fe_(3)O_(4) nanoparticle 3D structure(NG/Fe_(3)O_(4)).Compared with 3D graphene/Fe_(3)O_(4) structures prepared by the traditional hydrothermal method,the NG/Fe_(3)O_(4) supercapacitor prepared by the present method has a 153%improvement in specific capacitance,and there is no obvious decrease in specific capacitance after 1000 cycles.The present work provides a new and facile method to produce large-scale,3D,graphene-based materials with high specific capacitance for energy storage.展开更多
基金This project was supported by the National Natural Science Foundation of China （ No. 30100087, 30500148, 30571770）funded by the Collaborating Research Fund for Young Scholars from Abroad of National Natural Science Foundation of China （ No. 30228018 ）.
文摘Objective To identify the genetype of the PS1/APP double transgenie mouse model, then to analyse the histopathological changes in the brain and compare the differences between the transgenie mice models and Aβ1-40-injeeted rats models of Alzheimer disease. Methods The modified congo red staining, Nissl＇s staining and immunohistology staining was used to observe the Aβ deposits, activation of astrocyte respectively. Results ①The PS1/APP transgenic mouse extensively displayed Aβ deposits in the cortex and hippocampal structures, and GFAP positive cells were aggregated in mass and surrounded the congo red-positive plaque. ②The Aβ1-40-intrahippocmnpal-injeeted rat model showed the Aβ plaque deposits in the dentate gyrus of the hippocampus, with the astrocyte surrounded. The neurons loss was significant in the injection point and pin hole of injection with Nissl＇s staining methods. GFAP-positive cells increased significantly compared with the uninjected lateral of the hippocampus. Conclusion Although Aβ1-40-injected rat models could simulate some characteristic pathological features of human Alzheimer diseases, Aβ deposits and neurons loss in partial hippocampal, it would not simulate the progressive degenenration in the brain of AD. The double transgenie PS1/APP mice could simulate the specific pathogenesis and progressive changes of AD, mainly is Aβ deposits and the spongiocyte response , while no neurons loss were observed in this model.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFB0400904)the National Natural Science Foundation for Distinguished Young Scholars,China(Grant No.61725403)+5 种基金the National Natural Science Foundation of China(Grant Nos.61574142,61322406,61704171,and 11705206)the Key Program of International Partnership Program of the Chinese Academy of Sciences(Grant No.181722KYSB20160015)the Special Project for Inter-government Collaboration of State Key Research and Development Program,China(Grant No.2016YFE0118400)the Science and Technology Service Network Initiative of the Chinese Academy of Sciences,the Jilin Provincial Science&Technology Department,China(Grant No.20180201026GX)the Interdisciplinary Innovation Team of the Chinese Academy of Sciencesthe Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2015171)
文摘Ultraviolet(UV) photodetectors based on wide band gap semiconductor have attracted much attention for their small volume, low working voltage, long lifetime, good chemical and thermal stability. Up to now, many researches have been done on the semiconductors based UV detectors and some kinds of detectors have been made, such as metal–semiconductor–metal(MSM), Schottky, and PIN-type detectors. However, the sensitivity values of those detectors are still far from the expectation. Recent years, surface plasmon(SP) has been considered to be an effective way to enhance the sensitivity of semiconductor based UV photodetector. When the light is matched with the resonance frequency of surface plasmon, the localized field enhancement or scattering effect will happen and thus the spectral response will be enhanced.Here, we present an overview of surface plasmon enhancing the performance of UV detectors, including the GaN, ZnO,and other wide band gap semiconductor UV detectors. Both fundamental and experimental achievements are contained in this review.
基金supported by the National Key R&D Program of China(2016YFB0400101,2016YFB0400900)the National Natural Science Foundation of China(Grant Nos.61574142,61322406 and 61274038)+3 种基金the Special Project for Inter-government Collaboration of the State Key Research and Development Program(2016YFE0118400)the Jilin Provincial Science&Technology Department(Grant No.20150519001JH)the CAS Interdisciplinary Innovation Team,and the Youth Innovation Promotion Association of CAS(Grant No.2015171),For MIS's workthe support was provided by grant No.DE-FG02-11ER46789 from the Materials Sciences and Engineering Division,Office of the Basic Energy Sciences,Office of Science,U.S.Department of Energy.
文摘A surface plasmon(SP)is a fundamental excitation state that exists in metal nanostructures.Over the past several years,the performance of optoelectronic devices has been improved greatly via the SP enhancement effect.In our previous work,the responsivity of GaN ultraviolet detectors was increased by over 30 times when using Ag nanoparticles.However,the physics of the SP enhancement effect has not been established definitely because of the lack of experimental evidence.To reveal the physical origin of this enhancement,Kelvin probe force microscopy(KPFM)was used to observe the SP-induced surface potential reduction in the vicinity of Ag nanoparticles on a GaN epilayer.Under ultraviolet illumination,the localized field enhancement induced by the SP forces the photogenerated electrons to drift close to the Ag nanoparticles,leading to a reduction of the surface potential around the Ag nanoparticles on the GaN epilayer.For an isolated Ag nanoparticle with a diameter of~200 nm,the distribution of the SP localized field is located within 60 nm of the boundary of the Ag nanoparticle.For a dimer of Ag nanoparticles,the localized field enhancement between the nanoparticles was the strongest.The results presented here provide direct experimental proof of the localized field enhancement.These results not only explain the high performance of GaN detectors observed with the use of Ag nanoparticles but also reveal the physical mechanism of SP enhancement in optoelectronic devices,which will help us further understand and improve the performance of SP-based optoelectronic devices in the future.
基金funding by the National Natural Science Foundation of China(grant nos.61322406,61376020,11474035 and 61574021).
文摘Commonly used energy storage devices include stacked layers of active materials on two-dimensional sheets,and the limited specific surface area restricts the further development of energy storage.Three-dimensional(3D)structures with high specific surface areas would improve device performance.Herein,we present a novel procedure to fabricate macroscopic,high-quality,nitrogen-doped,3D graphene/nanoparticle aerogels.The procedure includes vacuum filtration,freeze-drying,and plasma treatment,which can be further expanded for large-scale production of nitrogen-doped,graphene-based aerogels.The behavior of the supercapacitor is investigated using a typical nitrogen-doped graphene/Fe_(3)O_(4) nanoparticle 3D structure(NG/Fe_(3)O_(4)).Compared with 3D graphene/Fe_(3)O_(4) structures prepared by the traditional hydrothermal method,the NG/Fe_(3)O_(4) supercapacitor prepared by the present method has a 153%improvement in specific capacitance,and there is no obvious decrease in specific capacitance after 1000 cycles.The present work provides a new and facile method to produce large-scale,3D,graphene-based materials with high specific capacitance for energy storage.
