Highly sensitive and uniform three-dimensional(3D)hybrid heterogeneous structures for use in surface-enhanced Raman scattering(SERS)experiments were fabricated by sequentially decorating high-quality,ultra-clean,graph...Highly sensitive and uniform three-dimensional(3D)hybrid heterogeneous structures for use in surface-enhanced Raman scattering(SERS)experiments were fabricated by sequentially decorating high-quality,ultra-clean,graphene quantum dots(GQDs)and Ag nanoparticles(Ag-NPs)onto 3D-graphene.Finite-difference time-domain calculations and scanning Kelvin probe microscopy were used to verify that the Ag-NPs/GQDs/3D-graphene system facilitates substantial electromagnetic enhancement(due to the occurrence of two kinds of"gaps"between the Ag-NPs that form 3D"hot spots")and additional chemical enhancement(in detecting someπ-conjugated molecules).The SERS mechanism was explored in further detail via experimental analysis and confirmed by performing theoretical calculations.The large surface area of the 3D substrate(due to the large specific surface areas of the GQDs and 3D-graphene)results in a better enrichment effect which helps produce lower detection limits.In particular,the detection limits obtained using the Ag-NPs/GQDs/3D-graphene platform can reach 10^(-11)M for rhodamine 6G,10^(-10)M for methylene blue and dopamine,and 10^(-7)M for tetramethylthiuram disulfide and methyl parathion in apple juice(these are superior to most of the results reported using graphene-based SERS substrates).In summary,the 3D-platform Ag-NPs/GQDs/3D-graphene/Si shows outstanding SERS performance.It therefore has excellent application prospects in biochemical molecular detection and food safety monitoring.展开更多
Flexible multichannel electrode arrays(fMEAs)with multiple flaments can be flexibly implanted in various patterns.It is necessary to develop a method for implanting the fMEA in different locations and at various depth...Flexible multichannel electrode arrays(fMEAs)with multiple flaments can be flexibly implanted in various patterns.It is necessary to develop a method for implanting the fMEA in different locations and at various depths based on the recording demands.This study proposed a strategy for reducing the microelectrode volume with integrated packaging.An implantation system was developed specifically for semiautomatic distributed implantation.The feasibility and convenience of the fMEA and implantation platform were verified in rodents.The acute and chronic recording results provied the effectiveness of the packaging and implantation methods.These methods could provide a novel strategy for developing fMEAs with more flaments and recording sites to measure functional interactions across multiple brain regions.展开更多
Electronic packaging materials and thermal interface materials(TIMs)are widely used in thermal management.In this study,the epoxy composites with core-shell structure SiC@SiO_(2) nanowires(SiC@SiO_(2) NWs)as fillers c...Electronic packaging materials and thermal interface materials(TIMs)are widely used in thermal management.In this study,the epoxy composites with core-shell structure SiC@SiO_(2) nanowires(SiC@SiO_(2) NWs)as fillers could effectively enhance the thermal conductivity of epoxy composites.The unique structure of fillers results in a high thermal conductivity of epoxy composites,which is attributed to good interfacial compatibility epoxy matrix and bridging connections of SiC@SiO_(2) NWs.From neat epoxy to 2.5 wt%loading of SiC@SiO_(2) NWs,the thermal conductivity is significantly increased from 0.218 to 0.391 W m^(−1) K^(−1),increased by 79.4%.In addition,the composite with 2.5 wt%filler possess lower coefficient of thermal expansion and better thermal stability than that of neat epoxy.All these outstanding properties imply that epoxy/SiC@SiO_(2) NWs composites could be the ideal candidate for TIM.展开更多
As the power density of electronic devices increases,there has been an urgent demand to develop highly conductive polymer composites to address the accompanying thermal management issues.Due to the ultra-high intrinsi...As the power density of electronic devices increases,there has been an urgent demand to develop highly conductive polymer composites to address the accompanying thermal management issues.Due to the ultra-high intrinsic thermal conductivity,graphene is considered a very promising filler to improve the thermal conductivity of polymers.However,graphene-based polymer composites prepared by the conventional mixing method generally have limited thermal conductivity,even under high graphene loading,due to the failure to construct efficient heat transfer pathways in the polymer matrix.Here,a spiral graphene framework(SGF)containing continuous and highly ordered graphene microtubes was developed based on a modified CVD method.After embedding into the epoxy(EP)matrix,the graphene microtubes can act as efficient heat pathways,endowing the SGF/EP composites with a high through-plane thermal conductivity of 1.35 W·m^(-1)·K^(-1) at an ultralow graphene loading of 0.86 wt%.This result gives a thermal conductivity enhancement per 1 wt%filler loading of 710%,significantly outperforming various graphene structures as fillers.In addition,we demonstrated the practical application of the SGF/EP composite as a thermal interface material for efficient thermal man-agement of the light-emitting diode(LED).展开更多
基金support provided by the National Natural Science Foundation of China under Grant(No.62174093)Guangdong Provincial Key Laboratory of Computational Science and Material Design(2019B030301001)+1 种基金Fundamental Research Program of Shenzhen(JCYJ20190809174203802)K.C.Wong Magna Fund in Ningbo University and Natural Science Foundation of Ningbo under Grant(No.202003 N4097).
文摘Highly sensitive and uniform three-dimensional(3D)hybrid heterogeneous structures for use in surface-enhanced Raman scattering(SERS)experiments were fabricated by sequentially decorating high-quality,ultra-clean,graphene quantum dots(GQDs)and Ag nanoparticles(Ag-NPs)onto 3D-graphene.Finite-difference time-domain calculations and scanning Kelvin probe microscopy were used to verify that the Ag-NPs/GQDs/3D-graphene system facilitates substantial electromagnetic enhancement(due to the occurrence of two kinds of"gaps"between the Ag-NPs that form 3D"hot spots")and additional chemical enhancement(in detecting someπ-conjugated molecules).The SERS mechanism was explored in further detail via experimental analysis and confirmed by performing theoretical calculations.The large surface area of the 3D substrate(due to the large specific surface areas of the GQDs and 3D-graphene)results in a better enrichment effect which helps produce lower detection limits.In particular,the detection limits obtained using the Ag-NPs/GQDs/3D-graphene platform can reach 10^(-11)M for rhodamine 6G,10^(-10)M for methylene blue and dopamine,and 10^(-7)M for tetramethylthiuram disulfide and methyl parathion in apple juice(these are superior to most of the results reported using graphene-based SERS substrates).In summary,the 3D-platform Ag-NPs/GQDs/3D-graphene/Si shows outstanding SERS performance.It therefore has excellent application prospects in biochemical molecular detection and food safety monitoring.
基金Acknowledgments We thank Drs Hua Gu (Columbia University, USA), Weiguo Zhang (Duke University Medical Center, USA), and Youhai H Chen (University of Pennsylvania, USA) for reviewing the manuscript and for suggestions, and Dr Ilia Voskoboinik (Peter MacCallum Cancer Centre, Australia) for providing the mouse perforin cDNA in pKS(+) Bluescript. Ragl^-/- mice were gifts from Xiaolong Liu (Shanghai Institutes for Biological Sciences, China). This work was supported by grants from the National Natural Science Foundation of China (30325018, 30530700, 30623003, and 30421005) and CAS project (KSCX1-YW-R-43), grants from the National Key Project 973 (2006CB504300 and 2007CB512404), grants from the Technology Commission of Shanghai Municipality (04DZ14902, 04DZ19108, 06DZ22032, 04DZ19112, 07XD14033, and 07DZ22916), 863 key project (2006AA02A247), and a grant from the E-institutes of Shanghai Universities Immunology Division.
文摘Perforin 是主要从事调停的形成毛孔的蛋白质目标 T 房间死亡并且被细胞毒素的 T 淋巴细胞(CTL ) 和自然漂亮房间采用。然而,它是否也在常规 CD4+ T 房间功能起一个作用,仍然保持不清楚。这里,我们报导那在 perforin 缺乏(PKO ) 老鼠, CD4+ T 房间是响应 T 的 hyperproliferative 房间受体(TCR ) 刺激。hyperproliferation 的这个特征被改进在房间分割并且在 IL-2 分泌物伴随。看起来, perforin 缺乏不在胸腺怒气和淋巴节点影响 T 房间开发。在 vivo, perforin 缺乏导致增加的抗原特定的 T 房间增长和抗体生产。而且, PKO 老鼠更产生试验性的自体免疫的眼色素层炎。探讨分子的机制,我们发现在 TCR 刺激以后,从 PKO 老鼠的 CD4+ T 房间显示增加的细胞内部的钙流动并且随后提高抄写因素 NFAT1 的激活。我们的结果显示 perforin 在由影响 TCR 依赖的 Ca2+ 发信号调整 CD4+ T 房间激活和有免疫力的反应起一个否定作用。
基金supported by the National Key Technologies Research and Development Program of China(2017YFA0205903,2017YFA0701100)the National Natural Science Foundation of China(61634006,62071447)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences Pilot Project(XDB32030102,XDB32040203,XDA16021305)the Key Research Programs of Frontier Sciences,CAS(QYZDY-SSW-JSC004).
文摘Flexible multichannel electrode arrays(fMEAs)with multiple flaments can be flexibly implanted in various patterns.It is necessary to develop a method for implanting the fMEA in different locations and at various depths based on the recording demands.This study proposed a strategy for reducing the microelectrode volume with integrated packaging.An implantation system was developed specifically for semiautomatic distributed implantation.The feasibility and convenience of the fMEA and implantation platform were verified in rodents.The acute and chronic recording results provied the effectiveness of the packaging and implantation methods.These methods could provide a novel strategy for developing fMEAs with more flaments and recording sites to measure functional interactions across multiple brain regions.
基金The authors are grateful for the financial support by the National Natural Science Foundation of China(51573201 and 51303034)Public Welfare Project of Zhejiang Province(2016C31026)International S&T Cooperation Program of Ningbo(2015D10003)。
文摘Electronic packaging materials and thermal interface materials(TIMs)are widely used in thermal management.In this study,the epoxy composites with core-shell structure SiC@SiO_(2) nanowires(SiC@SiO_(2) NWs)as fillers could effectively enhance the thermal conductivity of epoxy composites.The unique structure of fillers results in a high thermal conductivity of epoxy composites,which is attributed to good interfacial compatibility epoxy matrix and bridging connections of SiC@SiO_(2) NWs.From neat epoxy to 2.5 wt%loading of SiC@SiO_(2) NWs,the thermal conductivity is significantly increased from 0.218 to 0.391 W m^(−1) K^(−1),increased by 79.4%.In addition,the composite with 2.5 wt%filler possess lower coefficient of thermal expansion and better thermal stability than that of neat epoxy.All these outstanding properties imply that epoxy/SiC@SiO_(2) NWs composites could be the ideal candidate for TIM.
基金the National Natural Science Foundation of China(U1709205,52102055)the National Key R&D Program of China(2017YFE0128600)+7 种基金China Postdoctoral Science Foundation(2020M681965)the Project of the Chinese Academy of Sciences(XDC07030100,XDA22020602,KFZD-SW-409,ZDKYYQ20200001,and ZDRW-CN-2019-3)CAS Youth Innovation Promotion Association(2020301)Science and Technology Major Project of Ningbo(2018B10046)the Natural Science Foundation of Ningbo(2017A610010)Foundation of State Key Laboratory of Solid lubrication(LSL-1912)National Key Laboratory of Science and Technology on Advanced Composites in Special Environments(6142905192806)K.C.Wong Education Foundation(GJTD-2019-13).
文摘As the power density of electronic devices increases,there has been an urgent demand to develop highly conductive polymer composites to address the accompanying thermal management issues.Due to the ultra-high intrinsic thermal conductivity,graphene is considered a very promising filler to improve the thermal conductivity of polymers.However,graphene-based polymer composites prepared by the conventional mixing method generally have limited thermal conductivity,even under high graphene loading,due to the failure to construct efficient heat transfer pathways in the polymer matrix.Here,a spiral graphene framework(SGF)containing continuous and highly ordered graphene microtubes was developed based on a modified CVD method.After embedding into the epoxy(EP)matrix,the graphene microtubes can act as efficient heat pathways,endowing the SGF/EP composites with a high through-plane thermal conductivity of 1.35 W·m^(-1)·K^(-1) at an ultralow graphene loading of 0.86 wt%.This result gives a thermal conductivity enhancement per 1 wt%filler loading of 710%,significantly outperforming various graphene structures as fillers.In addition,we demonstrated the practical application of the SGF/EP composite as a thermal interface material for efficient thermal man-agement of the light-emitting diode(LED).