Interface emission from heterojunction is a shortcoming for electroluminescent devices.A buffer layer introduced in the heterojunctional interfaces is a potential solution for the challenge.However,the dynamics for ca...Interface emission from heterojunction is a shortcoming for electroluminescent devices.A buffer layer introduced in the heterojunctional interfaces is a potential solution for the challenge.However,the dynamics for carrier tunneling to control the interface emission is still a mystery.Herein,the low-refractive HfO_(2)with a proper energy band configuration is em-ployed as the buffer layer in achieving ZnO-microwire/HfO_(2)/GaN heterojunctional light-emitting diodes(LEDs).The optic-ally pumped lasing threshold and lifetime of the ZnO microwire are reduced with the introduced HfO_(2)layer.As a result,the interface emission is of blue-shift from visible wavelengths to 394 nm whereas the ultraviolet(UV)emission is en-hanced.To regulate the interface recombination between electrons in the conduction band of ZnO and holes in the valence band of GaN,the tunneling electrons with higher conduction band are employed to produce a higher tunneling current through regulation of thin HfO_(2)film causing blue shift and interface emission enhancement.Our results provide a method to control the tunneling electrons in heterojunction for high-performance LEDs.展开更多
The reversible storage of Zn^(2+)ions in Prussian blue analogues with typical aqueous solution was challenged by fast degradation and poor coulombic efficiency,while the mechanism is yet to be uncovered.This study cor...The reversible storage of Zn^(2+)ions in Prussian blue analogues with typical aqueous solution was challenged by fast degradation and poor coulombic efficiency,while the mechanism is yet to be uncovered.This study correlates the performance of the nickel hexacyanoferrate to the dynamics of H_(2)O in the electrolyte and the associated phase stability of the electrode.It demonstrates severe Ni dissolution in conventional diluted aqueous electrolyte(1 M ZnSO^(4)or 1 M Zn(TFSI)^(2)),leading to structure collapse with the formation of an electrochemical inert phase.This is regarded as the descriptor for the fast decay of nickel hexacyanoferrate in diluted aqueous electrolyte.However,a well-preserved open framework for zinc storage was obtained in concentrated aqueous electrolyte(1 M Zn(TFSI)_(2)+21 M LiTFSI)—the H_(2)O activity is highly suppressed by extensive coordination—thus,reversible capacity of 60.2 m Ah g^(-1)over 1600 cycles could be delivered.展开更多
Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-associated death worldwide.Angiogenesis,the process of formation of new blood vessels,is required for cancer cells to obtain nutrients and oxygen.HCC ...Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-associated death worldwide.Angiogenesis,the process of formation of new blood vessels,is required for cancer cells to obtain nutrients and oxygen.HCC is a typical hypervascular solid tumor with an aberrant vascular network and angiogenesis that contribute to its growth,progression,invasion,and metastasis.Current anti-angiogenic therapies target mainly tyrosine kinases,vascular endothelial growth factor receptor(VEGFR),and plateletderived growth factor receptor(PDGFR),and are considered effective strategies for HCC,particularly advanced HCC.However,because the survival benefits conferred by these anti-angiogenic therapies are modest,new anti-angiogenic targets must be identified.Several recent studies have determined the underlying molecular mechanisms,including pro-angiogenic factors secreted by HCC cells,the tumor microenvironment,and cancer stem cells.In this review,we summarize the roles of pro-angiogenic factors;the involvement of endothelial cells,hepatic stellate cells,tumor-associated macrophages,and tumor-associated neutrophils present in the tumor microenvironment;and the regulatory influence of cancer stem cells on angiogenesis in HCC.Furthermore,we discuss some of the clinically approved anti-angiogenic therapies and potential novel therapeutic targets for angiogenesis in HCC.A better understanding of the mechanisms underlying angiogenesis may lead to the development of more optimized anti-angiogenic treatment modalities for HCC.展开更多
Two-photon fluorescence (TPF) ellipsoid formed by a focused femtosecond laser into luminescent media serves as a fundamental pixel for TPF spatiotemporal imaging. Visualizing spatiotemporal evolution of the TPF ellips...Two-photon fluorescence (TPF) ellipsoid formed by a focused femtosecond laser into luminescent media serves as a fundamental pixel for TPF spatiotemporal imaging. Visualizing spatiotemporal evolution of the TPF ellipsoid itself in a selected luminescent medium is important for correctly reconstructing and interpreting spatiotemporal information of imaged targets. Here, we report a new spatiotemporal sectioning technique with a luminescent CsPbBr_(3) nanosheet and visualize the spatiotemporal evolution of TPF ellipsoid along the axial direction. Time-resolved axial lengths of TPF ellipsoids turn out to broaden nonlinearly with a turning point at about 600 ps. By comparison experiments, observed phenomena are attributed to photocarrier trapping and TPF photon recycling processes within CsPbBr_(3) nanosheets. The spatiotemporal sectioning technique is expected to be widely applicable, which will ignite a plethora of investigations and applications utilizing TPF ellipsoid.展开更多
van der Waals heterostructures(vdWHs)based on two-dimensional(2D)materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic devices.Herein,a WS_(2)/InSe vdWH pho...van der Waals heterostructures(vdWHs)based on two-dimensional(2D)materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic devices.Herein,a WS_(2)/InSe vdWH photodiode is proposed and fabricated by precisely stacking InSe and WS_(2)flakes through an all-dry transfer method.The WS_(2)/InSe vdWH forms an n–n heterojunction with strong built-in electric field due to their intrinsic n-type semiconductor characteristics and energy-band alignments with a large Fermi level offset between WS_(2)and InSe.As a result,the device displays excellent photovoltaic behavior with a large open voltage of 0.47 V and a short-circuit current of 11.7 nA under 520 nm light illumination.Significantly,a fast rising/decay time of 63/76μs,a large light on/off ratio of 105,a responsivity of 61 mA/W,a high detectivity of 2.5×10^(11) Jones,and a broadband photoresponse ranging from ultraviolet to near-infrared(325–980 nm)are achieved at zero bias.This study provides a strategy for developing high-performance self-powered broadband photodetectors based on 2D materials.展开更多
基金Ths work was supported by NSFC(11734005.62075041,61821002)Na tional Key Research and Development Program of China(2018YFA0209101,2017YFA0700500).
文摘Interface emission from heterojunction is a shortcoming for electroluminescent devices.A buffer layer introduced in the heterojunctional interfaces is a potential solution for the challenge.However,the dynamics for carrier tunneling to control the interface emission is still a mystery.Herein,the low-refractive HfO_(2)with a proper energy band configuration is em-ployed as the buffer layer in achieving ZnO-microwire/HfO_(2)/GaN heterojunctional light-emitting diodes(LEDs).The optic-ally pumped lasing threshold and lifetime of the ZnO microwire are reduced with the introduced HfO_(2)layer.As a result,the interface emission is of blue-shift from visible wavelengths to 394 nm whereas the ultraviolet(UV)emission is en-hanced.To regulate the interface recombination between electrons in the conduction band of ZnO and holes in the valence band of GaN,the tunneling electrons with higher conduction band are employed to produce a higher tunneling current through regulation of thin HfO_(2)film causing blue shift and interface emission enhancement.Our results provide a method to control the tunneling electrons in heterojunction for high-performance LEDs.
基金financial support provided by National Key Research and Development Program(No.2019YFA0210600)the National Natural Science Foundation of China(No.21905085+2 种基金No.51972107)the State Grid Shanghai Municipal Electric Power Company(No.B30970190001)the Innovative Research Groups of Hunan Province(No.2019JJ10001)
文摘The reversible storage of Zn^(2+)ions in Prussian blue analogues with typical aqueous solution was challenged by fast degradation and poor coulombic efficiency,while the mechanism is yet to be uncovered.This study correlates the performance of the nickel hexacyanoferrate to the dynamics of H_(2)O in the electrolyte and the associated phase stability of the electrode.It demonstrates severe Ni dissolution in conventional diluted aqueous electrolyte(1 M ZnSO^(4)or 1 M Zn(TFSI)^(2)),leading to structure collapse with the formation of an electrochemical inert phase.This is regarded as the descriptor for the fast decay of nickel hexacyanoferrate in diluted aqueous electrolyte.However,a well-preserved open framework for zinc storage was obtained in concentrated aqueous electrolyte(1 M Zn(TFSI)_(2)+21 M LiTFSI)—the H_(2)O activity is highly suppressed by extensive coordination—thus,reversible capacity of 60.2 m Ah g^(-1)over 1600 cycles could be delivered.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFA0803700)the National Natural Science Foundation of China(Grant Nos.91639108,81770272,and 81970425)+1 种基金the Beijing Natural Science Foundation(Grant No.7212044)the Beijing Hospital Authority Youth Program(Grant No.QML20190306)。
文摘Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-associated death worldwide.Angiogenesis,the process of formation of new blood vessels,is required for cancer cells to obtain nutrients and oxygen.HCC is a typical hypervascular solid tumor with an aberrant vascular network and angiogenesis that contribute to its growth,progression,invasion,and metastasis.Current anti-angiogenic therapies target mainly tyrosine kinases,vascular endothelial growth factor receptor(VEGFR),and plateletderived growth factor receptor(PDGFR),and are considered effective strategies for HCC,particularly advanced HCC.However,because the survival benefits conferred by these anti-angiogenic therapies are modest,new anti-angiogenic targets must be identified.Several recent studies have determined the underlying molecular mechanisms,including pro-angiogenic factors secreted by HCC cells,the tumor microenvironment,and cancer stem cells.In this review,we summarize the roles of pro-angiogenic factors;the involvement of endothelial cells,hepatic stellate cells,tumor-associated macrophages,and tumor-associated neutrophils present in the tumor microenvironment;and the regulatory influence of cancer stem cells on angiogenesis in HCC.Furthermore,we discuss some of the clinically approved anti-angiogenic therapies and potential novel therapeutic targets for angiogenesis in HCC.A better understanding of the mechanisms underlying angiogenesis may lead to the development of more optimized anti-angiogenic treatment modalities for HCC.
基金This work was supported by the National Natural Science Foundation of China(Nos.11734005,61704024,61821002,and 62075041)Natural Science Foundation of Jiangsu Province(No.BK20170696)+1 种基金the National Key Research and Development Program of China(Nos.2017YFA0700500 and 2018YFA0209101)Fundamental Research Funds for the Central Universities(No.2242021K10009).Q.N.C.gratefully acknowledges the support of Southeast University through Zhishan Young Scholar Fund.The authors thank Dr.Haibo Ding for insightful discussion.
文摘Two-photon fluorescence (TPF) ellipsoid formed by a focused femtosecond laser into luminescent media serves as a fundamental pixel for TPF spatiotemporal imaging. Visualizing spatiotemporal evolution of the TPF ellipsoid itself in a selected luminescent medium is important for correctly reconstructing and interpreting spatiotemporal information of imaged targets. Here, we report a new spatiotemporal sectioning technique with a luminescent CsPbBr_(3) nanosheet and visualize the spatiotemporal evolution of TPF ellipsoid along the axial direction. Time-resolved axial lengths of TPF ellipsoids turn out to broaden nonlinearly with a turning point at about 600 ps. By comparison experiments, observed phenomena are attributed to photocarrier trapping and TPF photon recycling processes within CsPbBr_(3) nanosheets. The spatiotemporal sectioning technique is expected to be widely applicable, which will ignite a plethora of investigations and applications utilizing TPF ellipsoid.
基金the National Natural Science Foundation of China(Nos.11734005,61821002,62075041,12004069,and 62204157)the National Key Research and Development Program of China(Nos.2018YFA0209101 and 2017YFA0700500)the Fundamental Research Funds for the Central Universities(No.2242021k10009).
文摘van der Waals heterostructures(vdWHs)based on two-dimensional(2D)materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic devices.Herein,a WS_(2)/InSe vdWH photodiode is proposed and fabricated by precisely stacking InSe and WS_(2)flakes through an all-dry transfer method.The WS_(2)/InSe vdWH forms an n–n heterojunction with strong built-in electric field due to their intrinsic n-type semiconductor characteristics and energy-band alignments with a large Fermi level offset between WS_(2)and InSe.As a result,the device displays excellent photovoltaic behavior with a large open voltage of 0.47 V and a short-circuit current of 11.7 nA under 520 nm light illumination.Significantly,a fast rising/decay time of 63/76μs,a large light on/off ratio of 105,a responsivity of 61 mA/W,a high detectivity of 2.5×10^(11) Jones,and a broadband photoresponse ranging from ultraviolet to near-infrared(325–980 nm)are achieved at zero bias.This study provides a strategy for developing high-performance self-powered broadband photodetectors based on 2D materials.
