Polymer-liquid crystals(PLCs)are common materials for smart windows.However,PLC smart windows usually require high driving voltage to maintain transparency.We synthesized a novel PLC smart film by doping multi-wall ca...Polymer-liquid crystals(PLCs)are common materials for smart windows.However,PLC smart windows usually require high driving voltage to maintain transparency.We synthesized a novel PLC smart film by doping multi-wall carbon nanotubes(MWCNTs)into a reverse-mode polymer network liquid crystal(R-PNLC).展开更多
Background:Colorectal cancer(CRC)is one of the most common malignancies.Early diagnosis is the key to effective treatment of CRC.Since microRNAs(miRNAs)can be used as biomarkers of CRC,the objective of this work was t...Background:Colorectal cancer(CRC)is one of the most common malignancies.Early diagnosis is the key to effective treatment of CRC.Since microRNAs(miRNAs)can be used as biomarkers of CRC,the objective of this work was to examine the effect of miR-520f-3p,which targets YAP1(Yes-associated protein 1),on the ability of CRC cells to proliferate,invade,migrate,and undergo epithelial-mesenchymal transition(EMT).Methods:A miR-520f-3p mimic was used to overexpress miR-520f-3p in HT29 cells.To establish the tumor-bearing mouse model,transfected HT29 cells were subcutaneously implanted into BALB/c-nu nude mice,and YAP1 and miR-520f-3p levels were determined using qRT‒PCR.The viability,invasion ability,and migration ability of cells were evaluated by CCK-8,Transwell,and wound healing assays.Apoptosis was detected by flow cytometry and TUNEL assays.The regulatory link between miR-520f-3p and the YAP1 gene was examined by dual-luciferase reporter assay.Tumor tissues with positive Ki-67 expression were identified by immunohistochemistry.Vimentin,E-cadherin,and YAP1 expression were evaluated by western blotting.Results:MiR-520f-3p overexpression could inhibit proliferation,invasion,migration,and EMT and induce apoptosis in HT29 cells.YAP1 was found as a target of miR-520f-3p.The inhibitory effects of miR-520f-3p on proliferation,invasion,migration,and EMT may be reversed by overexpressing YAP1.In tumor-bearing mice,miR-520f-3p overexpression reduced the Ki-67 level,increased apoptosis,and prevented tumor development and spread.Conclusion:By targeting YAP1,miR-520f-3p may be capable of suppressing CRC cell proliferation,invasion,migration,and EMT,providing a novel therapeutic target for the disease.展开更多
A cylindrical vector beam is utilized to enhance the energy scale of the pulse post-compressed in a bulk-material Herriott multi-pass cell(MPC).The method proposed here enables,for the first time to the best of our kn...A cylindrical vector beam is utilized to enhance the energy scale of the pulse post-compressed in a bulk-material Herriott multi-pass cell(MPC).The method proposed here enables,for the first time to the best of our knowledge,pulse compression from 14 ps down to 475 fs with throughput energy beyond 1 mJ,corresponding to a compression ratio of 30,which is the highest pulse energy and compression ratio in single-stage bulk-material MPCs.Furthermore,we demonstrate the characteristic of the vector polarization beam is preserved in the MPC.展开更多
We report the observation for the pz electron band and the band inversion in Fe1+yTexSe1-xwith angleresolved photoemission spectroscopy. Furthermore, we found that excess Fe(y>0) inhibits the topological band inver...We report the observation for the pz electron band and the band inversion in Fe1+yTexSe1-xwith angleresolved photoemission spectroscopy. Furthermore, we found that excess Fe(y>0) inhibits the topological band inversion in Fe1+yTexSe1-x,which explains the absence of Majorana zero modes in previous reports for Fe1+yTexSe1-xwith excess Fe. Based on our analysis of different amounts of Te doping and excess Fe, we propose a delicate topological phase in this material. Thanks to this delicate phase, one may be able to tune the topological transition via applying lattice strain or carrier doping.展开更多
We report a study of the electronic structure of BaFe_(2)As_(2) under uniaxial strains using angle-resolved photoemission spectroscopy and transport measurements. Two electron bands at the MY point, with an energy spl...We report a study of the electronic structure of BaFe_(2)As_(2) under uniaxial strains using angle-resolved photoemission spectroscopy and transport measurements. Two electron bands at the MY point, with an energy splitting of 50 meV in the strain-free sample, shift downward and merge into each other under a large uniaxial strain, while three hole bands at theГ point shift downward together. However, we also observed an enhancement of the resistance anisotropy under uniaxial strains by electrical transport measurements, implying that the applied strains strengthen the electronic nematic order in BaFe_(2)As_(2). These observations suggest that the splitting of these two electron bands at the MY point is not caused by the nematic order in BaFe_(2)As_(2).展开更多
Nanomaterials based on nickel foam(NF) have been widely applied in energy conversion and storage field.Traditional synthesis methods such as hydrothermal method which is dangerous and high cost limited the scalable de...Nanomaterials based on nickel foam(NF) have been widely applied in energy conversion and storage field.Traditional synthesis methods such as hydrothermal method which is dangerous and high cost limited the scalable developments.Herein,we report a fast,simple,and low-cost synthesis method of nanomaterials based on NF by Joule-heating and water soaking treatment.Thin carbon-coated CoS on NF(NF-C/CoS) was synthesized by Joule-heating for a few seconds with rapid cooling.And then,NF-C/CoS/NiOOH with core-shell heterostructure was fabricated by soaking treatment of NF-C/CoS in water on which NiOOH nanosheets grew spontaneously.The formation mechanism is proposed that the coordination complex precursor converts into C/CoS on NF driven by Joule-heating,and the nickel on the surface of NF is activated to form metastable nickel simultaneously.The metastable nickel reacting with water leads to the formation of NiOOH,and the induction of CoS makes NiOOH grow continuously.This synthesis technology provides a new route to manufacture NF-based nanostructures,and the as-fabricated NF-C/CoS/NiOOH exhibits great potential as electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction.展开更多
Discrimination of dislocations is critical to the statistics of dislocation densities in 4H silicon carbide(4H-SiC),which are routinely used to evaluate the quality of 4H-SiC single crystals and homoepitaxial layers.I...Discrimination of dislocations is critical to the statistics of dislocation densities in 4H silicon carbide(4H-SiC),which are routinely used to evaluate the quality of 4H-SiC single crystals and homoepitaxial layers.In this work,we show that the inclination angles of the etch pits of molten-alkali etched 4H-SiC can be adopted to discriminate threading screw dislocations(TSDs),threading edge dislocations(TEDs)and basal plane dislocations(BPDs)in 4H-SiC.In n-type 4H-SiC,the inclination angles of the etch pits of TSDs,TEDs and BPDs in molten-alkali etched 4H-SiC are in the ranges of 27°−35°,8°−15°and 2°−4°,respectively.In semi-insulating 4H-SiC,the inclination angles of the etch pits of TSDs and TEDs are in the ranges of 31°−34°and 21°−24°,respectively.The inclination angles of dislocation-related etch pits are independent of the etching duration,which facilitates the discrimination and statistic of dislocations in 4H-SiC.More significantly,the inclination angle of a threading mixed dislocations(TMDs)is found to consist of characteristic angles of both TEDs and TSDs.This enables to distinguish TMDs from TSDs in 4H-SiC.展开更多
The architecture of edge-cloud cooperation is proposed as a compromising solution that combines the advantage of MEC and central cloud. In this paper we investigated the problem of how to reduce the average delay of M...The architecture of edge-cloud cooperation is proposed as a compromising solution that combines the advantage of MEC and central cloud. In this paper we investigated the problem of how to reduce the average delay of MEC application by collaborative task scheduling. The collaborative task scheduling is modeled as a constrained shortest path problem over an acyclic graph. By characterizing the optimal solution, the constrained optimization problem is simplified according to one-climb theory and enumeration algorithm. Generally, the edge-cloud collaborative task scheduling scheme performance better than independent scheme in reducing average delay. In heavy workload scenario, high blocking probability and retransmission delay at MEC is the key factor for average delay. Hence, more task executed on central cloud with abundant resource is the optimal scheme. Otherwise, transmission delay is inevitable compared with execution delay. MEC configured with higher priority and deployed close to terminals obtain more performance gain.展开更多
One of the greatest triumph of condensed matter physics in the past ten years is the classification of materials by the principle of topology.The existence of topological protected dissipationless surface state makes ...One of the greatest triumph of condensed matter physics in the past ten years is the classification of materials by the principle of topology.The existence of topological protected dissipationless surface state makes topological insulators great potential for applications and hotly studied.However,compared with the prosperity of strong topological insulators,theoretical predicted candidate materials and experimental confirmation of weak topological insulators(WTIs) are both extremely rare.By combining systematic first-principles calculation and angle-resolved photoemission spectroscopy measurements,we have studied the electronic structure of the dark surface of the WTI candidate Zintl Ba_(3)Cd_(2)Sb_(4)and another related material Ba_(3)Cd_(2)As_(4).The existence of two Dirac surface states on specific side surfaces predicted by theoretical calculations and the observed two band inversions in the Brillouin zone give strong evidence to prove that the Ba_(3)Cd_(2)Sb_(4)is a WTI.The spectroscopic characterization of this Zintl Ba_(3)Cd_(2)N_(4)(N = As and Sb) family materials will facilitate applications of their novel topological properties.展开更多
Hepatic myelopathy(HM)is a rare neurological complication in the end stage of many liver diseases and is characterized by bilateral spastic paraparesis without sensory and sphinc-ter dysfunction.It occurs owing to met...Hepatic myelopathy(HM)is a rare neurological complication in the end stage of many liver diseases and is characterized by bilateral spastic paraparesis without sensory and sphinc-ter dysfunction.It occurs owing to metabolic disorders and central nervous system dysfunction associated with cirrhosis.Without timely and effective clinical intervention,the progno-sis of these patients is devastating.Although liver transplan-tation(LT)is an effective treatment for HM,the prognosis of these patients remains unsatisfactory.Early recognition and diagnosis of this disease are essential for improving patient prognosis.Here,we report a case of hepatitis B virus-asso-ciated decompensated cirrhosis with HM.The patient recov-ered well after LT.We also summarize the clinical character-istics and post-transplant outcomes of 25 patients with HM treated by LT through 2023,including this case.展开更多
Three types of carbon nano-onions（CNOs） including Ni@CNOs.Fe3C@CNOs and Fe0.64Ni0.36@CNOs nanoparticles have been synthesized by catalytic decomposition of methane at 850 ℃ using nickel,iron and iron-nickel alloy c...Three types of carbon nano-onions（CNOs） including Ni@CNOs.Fe3C@CNOs and Fe0.64Ni0.36@CNOs nanoparticles have been synthesized by catalytic decomposition of methane at 850 ℃ using nickel,iron and iron-nickel alloy catalysts.Comparative and systematic studies have been carried out on the morphology,structural characteristics and graphitic crystallinity of these CNOs products.Furthermore,the electrochemical hydrogen storage properties of three types of CNOs have been investigated.Measurements show that the Ni@CNOs have the highest discharge capacity of 387.2 mAh/g,coiTesponding to a hydrogen storage of 1.42%.This comparison study shows the advantages of each catalyst in the growth of CNOs.enabling the controllable synthesis and tuning the properties of CNOs by mediating different metals and their alloy for using in the fuel cell system.展开更多
With the development of optical technologies,transparent materials that provide protection from light have received considerable attention from scholars.As important channels for external light,windows play a vital ro...With the development of optical technologies,transparent materials that provide protection from light have received considerable attention from scholars.As important channels for external light,windows play a vital role in the regulation of light in buildings,vehicles,and aircrafts.There is a need for windows with switchable optical properties to prevent or attenuate damage or interference to the human eye and light-sensitive instruments by inappropriate optical radiation.In this context,liquid crystals(LCs),owing to their rich responsiveness and unique optical properties,have been considered among the best candidates for advanced light protection materials.In this review,we provide an overview of advances in research on LC-based methods for protection against light.First,we introduce the characteristics of different light sources and their protection requirements.Second,we introduce several classes of light modulation principles based on liquid crystal materials and demonstrate the feasibility of using them for light protection.In addition,we discuss current light protection strategies based on liquid crystal materials for different applications.Finally,we discuss the problems and shortcomings of current strategies.We propose several suggestions for the development of liquid crystal materials in the field of light protection.展开更多
Long-term variations in population structure,growth,mortality,length at median sexual maturity,and exploitation rate of threadfin bream(Nemipterus virgatus)are reported based on bottom trawl survey data collected duri...Long-term variations in population structure,growth,mortality,length at median sexual maturity,and exploitation rate of threadfin bream(Nemipterus virgatus)are reported based on bottom trawl survey data collected during 1960-2012 in the Beibu Gulf,South China Sea.Laboratory-based analyses were conducted on 16791 individuals collected quarterly in eight different sampling years.Average body length,estimated asymptotic length,and percentage of large individuals have decreased significantly with the growth of marine catch and fishing power,indicating individual miniaturization of this fish species.Estimated exploitation rates indicate that the N.virgatus stock in the Beibu Gulf was moderately exploited in 1960 and 1962 and overexploited after 1992.This stock was taking a good turn in status in 2012,with the lowest exploitation rate since 1992 and ceased downward trend in length indexes.These results suggest that management measures to reduce fishing pressure may have a positive influence on the biological characteristics of this commercial fish species.Biological characteristics of most commercial fish species have phenotypic plasticity and might change over years in response to fisheries management.Therefore,attentions should be paid on variations in fish biological characteristics,when evaluating the effectiveness of current measures to control the total catch for all fisheries.展开更多
Kagome lattice,characterized by two-dimensional honeycomb network of corner-sharing triangles[1],presents flat bands,Dirac cones,and van Hove singularities(VHSs),which have been theoretically predicted and experimenta...Kagome lattice,characterized by two-dimensional honeycomb network of corner-sharing triangles[1],presents flat bands,Dirac cones,and van Hove singularities(VHSs),which have been theoretically predicted and experimentally observed[2-4].When combined with spin-orbit coupling(SOC)and magnetism,novel properties have emerged.Although kagome materials vary,most of their strong interlayer interactions make the synthesized crystals not layered,and the properties deviating from the raw two-dimensional kagome lattices.These crystals are difficult to fabricate into thin devices and to tune the physical properties of the materials using gate voltage.展开更多
Low photothermal conversion efficiency restricts the antibacterial application of photothermal materials.In this work,two-dimensional carbon nanosheets(2D C)were prepared and decorated with Cu nanoparticles(2D C/Cu)by...Low photothermal conversion efficiency restricts the antibacterial application of photothermal materials.In this work,two-dimensional carbon nanosheets(2D C)were prepared and decorated with Cu nanoparticles(2D C/Cu)by using a simple soluble salt template method combined with ultrasonic exfoliation.The photothermal conversion efficiency of 2 D C/Cu system can be optimized by changing the content of Cu nanoparticles,where the 2D C/Cu2 showed the best photothermal conversion efficiency(á)of 65.05%under 808 nm near-infrared light irradiation.In addition,the photothermal performance can affect the release behavior of Cu ions.This superior photothermal property combined with released Cu ions can endow this 2D hybrid material with highly efficient antibacterial efficacy of 99.97%±0.01%,99.96%±0.01%,99.97%±0.01%against Escherichia coli,Staphylococcus aureus,and methicillin-resistant Staphylococcus aureus,respectively,because of the synergetic effect of photothermy and ion release.In addition,this 2D hybrid system exhibited good cytocompatibility.Hence,this study provides a novel strategy to enhance the photothermal performance of 2D materials and thus will be beneficial for development of antibiotics-free antibacterial materials with safe and highly efficient bactericidal activity.展开更多
Stimulated emission depletion(STED) microscope is one of the most prominent super-resolution bio-imaging instruments, which holds great promise for ultrahigh-resolution imaging of cells. To construct a STED microscope...Stimulated emission depletion(STED) microscope is one of the most prominent super-resolution bio-imaging instruments, which holds great promise for ultrahigh-resolution imaging of cells. To construct a STED microscope, it is challenging to realize temporal synchronization between the excitation pulses and the depletion pulses. In this study, we present a simple and low-cost method to achieve pulse synchronization by using a condensed fluorescent dye as a depletion indicator. By using this method, almost all the confocal microscopes can be upgraded to a STED system without losing its original functions. After the pulse synchronization,our STED system achieved sub-100-nm resolution for fluorescent nanospheres and single-cell imaging.展开更多
Biofilms are closely associated with the tough healing and dysfunctional inflammation of chronic wounds.Photothermal therapy(PTT)emerged as a suitable alternative which could destroy the structure of biofilms with loc...Biofilms are closely associated with the tough healing and dysfunctional inflammation of chronic wounds.Photothermal therapy(PTT)emerged as a suitable alternative which could destroy the structure of biofilms with local physical heat.However,the efficacy of PTT is limited because the excessive hyperthermia could damage surrounding tissues.Besides,the difficult reserve and delivery of photothermal agents makes PTT hard to eradicate biofilms as expectation.Herein,we present a GelMA-EGF/Gelatin-MPDA-LZM bilayer hydrogel dressing to perform lysozyme-enhanced PTT for biofilms eradication and a further acceleration to the repair of chronic wounds.Gelatin was used as inner layer hydrogel to reserve lysozyme(LZM)loaded mesoporous polydopamine(MPDA)(MPDA-LZM)nanoparticles,which could rapidly liquefy while temperature rising so as to achieve a bulk release of nanoparticles.MPDA-LZM nanoparticles serve as photothermal agents with antibacterial capability,could deeply penetrate and destroy biofilms.In addition,the outer layer hydrogel consisted of gelatin methacryloyl(GelMA)and epidermal growth factor(EGF)promoted wound healing and tissue regeneration.It displayed remarkable efficacy on alleviating infection and accelerating wound healing in vivo.Overall,the innovative therapeutic strategy we came up with has significant effect on biofilms eradication and shows promising application in promoting the repair of clinical chronic wounds.展开更多
To synthesize graphene economically and efficiently,as well as to improve the interface bonding between graphene and metal and to recede the aggregation issue of graphene,in this work,an easy and scalable bottom-up st...To synthesize graphene economically and efficiently,as well as to improve the interface bonding between graphene and metal and to recede the aggregation issue of graphene,in this work,an easy and scalable bottom-up strategy for the mass production of metal nanoparticles modified graphene nanoplates(GNPs)was proposed.Cu nanoparticles modified GNPs(Cu-GNPs)and Ni nanoparticles modified GNPs(Ni-GNPs)were fabricated through this method,and then compounded with Al via ball milling technique.The asobtained Ni-GNPs/Al composite showed simultaneously improved strength and toughness compared with unreinforced Al,while the Cu-GNPs/Al composite presented a greater strengthening effect.The microstructure and interface of the two composites were carefully characterized and investigated to reveal the difference.First principle study was also adopted to explore the binding energy of different interface structures.This study could provide new insights into the fabrication of GNPs and the control of interface in GNPs/Al composites.展开更多
Exosomes play critical roles in regulating various physiological and pathological processes,including immune stimulation,immune suppression,cardiovascular diseases,and cancers.Recent studies show that exosomes that tr...Exosomes play critical roles in regulating various physiological and pathological processes,including immune stimulation,immune suppression,cardiovascular diseases,and cancers.Recent studies show that exosomes that transport specific microRNAs(miRNAs)are involved in tumor development.However,the molecular mechanism by which tumor invasion and migration are regulated by exosomes from non-small cell lung cancer(NSCLC)is not well understood.Here,we show that exosomes shuttling low levels of miR-34c-3p are involved in NSCLC progression.Our results showed that exosomes derived from NSCLC cells carrying low levels of miR-34c-3p could be transported into the cytoplasm of NSCLC cells and accelerate NSCLC invasion and migration by upregulating integrinα2β1.A luciferase assay revealed that integrinα2β1 was the direct target of miR-34c-3p,and overexpression of integrinα2β1 could promote the invasion and migration of NSCLC cells.The analysis of exosomes derived from clinical serum samples indicated that the expression of miR-34c-3p was significantly downregulated in exosomes from NSCLC patients compared with that of normal controls.A549-derived exosomes promoted NSCLC cells lung metastases in vivo.Exosomes shuttling low levels of miR-34c-3p were associated with the progression of NSCLC in vitro and in vivo.Our data demonstrate that exosomes shuttling low levels of miR-34c-3p can accelerate the invasion and migration of NSCLC by upregulating integrinα2β1.MiR-34c-3p can be a diagnostic and prognostic marker for NSCLC.High expression of integrinα2β1 is positively related to the migration and metastasis of NSCLC cells.展开更多
基金Supported by the China National Key R&D Program during the 14th Five-Year Plan Period(Grant No.2023YFB3811600)the Major Program of Harbin Institute of Technology(Grant No.2023FRFK01002)。
文摘Polymer-liquid crystals(PLCs)are common materials for smart windows.However,PLC smart windows usually require high driving voltage to maintain transparency.We synthesized a novel PLC smart film by doping multi-wall carbon nanotubes(MWCNTs)into a reverse-mode polymer network liquid crystal(R-PNLC).
文摘Background:Colorectal cancer(CRC)is one of the most common malignancies.Early diagnosis is the key to effective treatment of CRC.Since microRNAs(miRNAs)can be used as biomarkers of CRC,the objective of this work was to examine the effect of miR-520f-3p,which targets YAP1(Yes-associated protein 1),on the ability of CRC cells to proliferate,invade,migrate,and undergo epithelial-mesenchymal transition(EMT).Methods:A miR-520f-3p mimic was used to overexpress miR-520f-3p in HT29 cells.To establish the tumor-bearing mouse model,transfected HT29 cells were subcutaneously implanted into BALB/c-nu nude mice,and YAP1 and miR-520f-3p levels were determined using qRT‒PCR.The viability,invasion ability,and migration ability of cells were evaluated by CCK-8,Transwell,and wound healing assays.Apoptosis was detected by flow cytometry and TUNEL assays.The regulatory link between miR-520f-3p and the YAP1 gene was examined by dual-luciferase reporter assay.Tumor tissues with positive Ki-67 expression were identified by immunohistochemistry.Vimentin,E-cadherin,and YAP1 expression were evaluated by western blotting.Results:MiR-520f-3p overexpression could inhibit proliferation,invasion,migration,and EMT and induce apoptosis in HT29 cells.YAP1 was found as a target of miR-520f-3p.The inhibitory effects of miR-520f-3p on proliferation,invasion,migration,and EMT may be reversed by overexpressing YAP1.In tumor-bearing mice,miR-520f-3p overexpression reduced the Ki-67 level,increased apoptosis,and prevented tumor development and spread.Conclusion:By targeting YAP1,miR-520f-3p may be capable of suppressing CRC cell proliferation,invasion,migration,and EMT,providing a novel therapeutic target for the disease.
文摘A cylindrical vector beam is utilized to enhance the energy scale of the pulse post-compressed in a bulk-material Herriott multi-pass cell(MPC).The method proposed here enables,for the first time to the best of our knowledge,pulse compression from 14 ps down to 475 fs with throughput energy beyond 1 mJ,corresponding to a compression ratio of 30,which is the highest pulse energy and compression ratio in single-stage bulk-material MPCs.Furthermore,we demonstrate the characteristic of the vector polarization beam is preserved in the MPC.
基金supported by the National Natural Science Foundation of China(Grant Nos.11888101 and U1832202)the Chinese Academy of Sciences(Grant Nos.QYZDB-SSW-SLH043,XDB28000000,and XDB33000000)+3 种基金the K.C.Wong Education Foundation(Grant No.GJTD-2018-01)the Informatization Plan of Chinese Academy of Sciences(Grant No.CAS-WX2021SF-0102)supported by the Synergetic Extreme Condition User Facility(SECUF)supported by US DOE(Grant Nos.DESC0010526 and DE-SC0012704)。
文摘We report the observation for the pz electron band and the band inversion in Fe1+yTexSe1-xwith angleresolved photoemission spectroscopy. Furthermore, we found that excess Fe(y>0) inhibits the topological band inversion in Fe1+yTexSe1-x,which explains the absence of Majorana zero modes in previous reports for Fe1+yTexSe1-xwith excess Fe. Based on our analysis of different amounts of Te doping and excess Fe, we propose a delicate topological phase in this material. Thanks to this delicate phase, one may be able to tune the topological transition via applying lattice strain or carrier doping.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11888101 and U1832202)the Chinese Academy of Sciences (Grant Nos.QYZDB-SSWSLH043,XDB28000000,and XDB33000000)+1 种基金the K.C.Wong Education Foundation (Grant No.GJTD-2018-01)the Informatization Plan of Chinese Academy of Sciences (Grant No.CAS-WX2021SF-0102)。
文摘We report a study of the electronic structure of BaFe_(2)As_(2) under uniaxial strains using angle-resolved photoemission spectroscopy and transport measurements. Two electron bands at the MY point, with an energy splitting of 50 meV in the strain-free sample, shift downward and merge into each other under a large uniaxial strain, while three hole bands at theГ point shift downward together. However, we also observed an enhancement of the resistance anisotropy under uniaxial strains by electrical transport measurements, implying that the applied strains strengthen the electronic nematic order in BaFe_(2)As_(2). These observations suggest that the splitting of these two electron bands at the MY point is not caused by the nematic order in BaFe_(2)As_(2).
基金supported by the National Natural Science Foundation of China (Nos. 91963113, 51701139, and U1601216)。
文摘Nanomaterials based on nickel foam(NF) have been widely applied in energy conversion and storage field.Traditional synthesis methods such as hydrothermal method which is dangerous and high cost limited the scalable developments.Herein,we report a fast,simple,and low-cost synthesis method of nanomaterials based on NF by Joule-heating and water soaking treatment.Thin carbon-coated CoS on NF(NF-C/CoS) was synthesized by Joule-heating for a few seconds with rapid cooling.And then,NF-C/CoS/NiOOH with core-shell heterostructure was fabricated by soaking treatment of NF-C/CoS in water on which NiOOH nanosheets grew spontaneously.The formation mechanism is proposed that the coordination complex precursor converts into C/CoS on NF driven by Joule-heating,and the nickel on the surface of NF is activated to form metastable nickel simultaneously.The metastable nickel reacting with water leads to the formation of NiOOH,and the induction of CoS makes NiOOH grow continuously.This synthesis technology provides a new route to manufacture NF-based nanostructures,and the as-fabricated NF-C/CoS/NiOOH exhibits great potential as electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction.
基金supported by“Pioneer”and“Leading Goose”R&D Program of Zhejiang(Grant No.2022C01021)National Key Research and Development Program of China(Grant Nos.2018YFB2200101)+3 种基金Natural Science Foundation of China(Grant Nos.61774133)Fundamental Research Funds for the Central Universities(Grant No.2018XZZX003-02)Natural Science Foundation of China for Innovative Research Groups(Grant No.61721005)Zhejiang University Education Foundation Global Partnership Fund.
文摘Discrimination of dislocations is critical to the statistics of dislocation densities in 4H silicon carbide(4H-SiC),which are routinely used to evaluate the quality of 4H-SiC single crystals and homoepitaxial layers.In this work,we show that the inclination angles of the etch pits of molten-alkali etched 4H-SiC can be adopted to discriminate threading screw dislocations(TSDs),threading edge dislocations(TEDs)and basal plane dislocations(BPDs)in 4H-SiC.In n-type 4H-SiC,the inclination angles of the etch pits of TSDs,TEDs and BPDs in molten-alkali etched 4H-SiC are in the ranges of 27°−35°,8°−15°and 2°−4°,respectively.In semi-insulating 4H-SiC,the inclination angles of the etch pits of TSDs and TEDs are in the ranges of 31°−34°and 21°−24°,respectively.The inclination angles of dislocation-related etch pits are independent of the etching duration,which facilitates the discrimination and statistic of dislocations in 4H-SiC.More significantly,the inclination angle of a threading mixed dislocations(TMDs)is found to consist of characteristic angles of both TEDs and TSDs.This enables to distinguish TMDs from TSDs in 4H-SiC.
文摘The architecture of edge-cloud cooperation is proposed as a compromising solution that combines the advantage of MEC and central cloud. In this paper we investigated the problem of how to reduce the average delay of MEC application by collaborative task scheduling. The collaborative task scheduling is modeled as a constrained shortest path problem over an acyclic graph. By characterizing the optimal solution, the constrained optimization problem is simplified according to one-climb theory and enumeration algorithm. Generally, the edge-cloud collaborative task scheduling scheme performance better than independent scheme in reducing average delay. In heavy workload scenario, high blocking probability and retransmission delay at MEC is the key factor for average delay. Hence, more task executed on central cloud with abundant resource is the optimal scheme. Otherwise, transmission delay is inevitable compared with execution delay. MEC configured with higher priority and deployed close to terminals obtain more performance gain.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFA1403800,2018YFA0305700,and 2019YFA0308602)the Chinese Academy of Sciences(Grant Nos.QYZDB-SSW-SLH043,XDB33000000,and XDB28000000)+2 种基金the National Natural Science Foundation of China (Grant Nos.U22A600018,U1832202,12074425,11874422,11925408,11921004,and 12188101)the Informatization Plan of Chinese Academy of Sciences (Grant No.CAS-WX2021SF-0102)the Synergetic Extreme Condition User Facility (SECUF)。
文摘One of the greatest triumph of condensed matter physics in the past ten years is the classification of materials by the principle of topology.The existence of topological protected dissipationless surface state makes topological insulators great potential for applications and hotly studied.However,compared with the prosperity of strong topological insulators,theoretical predicted candidate materials and experimental confirmation of weak topological insulators(WTIs) are both extremely rare.By combining systematic first-principles calculation and angle-resolved photoemission spectroscopy measurements,we have studied the electronic structure of the dark surface of the WTI candidate Zintl Ba_(3)Cd_(2)Sb_(4)and another related material Ba_(3)Cd_(2)As_(4).The existence of two Dirac surface states on specific side surfaces predicted by theoretical calculations and the observed two band inversions in the Brillouin zone give strong evidence to prove that the Ba_(3)Cd_(2)Sb_(4)is a WTI.The spectroscopic characterization of this Zintl Ba_(3)Cd_(2)N_(4)(N = As and Sb) family materials will facilitate applications of their novel topological properties.
基金supported by The National Natural Scientific Foundation of China(Grant No.81972230).
文摘Hepatic myelopathy(HM)is a rare neurological complication in the end stage of many liver diseases and is characterized by bilateral spastic paraparesis without sensory and sphinc-ter dysfunction.It occurs owing to metabolic disorders and central nervous system dysfunction associated with cirrhosis.Without timely and effective clinical intervention,the progno-sis of these patients is devastating.Although liver transplan-tation(LT)is an effective treatment for HM,the prognosis of these patients remains unsatisfactory.Early recognition and diagnosis of this disease are essential for improving patient prognosis.Here,we report a case of hepatitis B virus-asso-ciated decompensated cirrhosis with HM.The patient recov-ered well after LT.We also summarize the clinical character-istics and post-transplant outcomes of 25 patients with HM treated by LT through 2023,including this case.
基金supported by the National Natural Science Foundation of China(51272173,51002188)the National Basic Research Program of China(2010CB934703)Tianjin Municipal Science and Technology Commission(12ZCZDGX00800)
文摘Three types of carbon nano-onions（CNOs） including Ni@CNOs.Fe3C@CNOs and Fe0.64Ni0.36@CNOs nanoparticles have been synthesized by catalytic decomposition of methane at 850 ℃ using nickel,iron and iron-nickel alloy catalysts.Comparative and systematic studies have been carried out on the morphology,structural characteristics and graphitic crystallinity of these CNOs products.Furthermore,the electrochemical hydrogen storage properties of three types of CNOs have been investigated.Measurements show that the Ni@CNOs have the highest discharge capacity of 387.2 mAh/g,coiTesponding to a hydrogen storage of 1.42%.This comparison study shows the advantages of each catalyst in the growth of CNOs.enabling the controllable synthesis and tuning the properties of CNOs by mediating different metals and their alloy for using in the fuel cell system.
基金supported by the following grants:Key Project of National Natural Science Foundation of China(Grant No.52032004)National Natural Science Foundation for Distinguished Young Scholars of China(Grant No.51625201)+4 种基金National Natural Science Funds of China(Grant No.52102039)China Postdoctoral Science Foundation(Grant No.2021M700036)The Open Fund of State Key Laboratory of Advanced Welding and Joining(Grant No.AWJ-22Z04)National Defense Supporting Scientific Research Projects(186)Keypoint Research and Invention Program of Heilongjiang Province(GA21D001).
文摘With the development of optical technologies,transparent materials that provide protection from light have received considerable attention from scholars.As important channels for external light,windows play a vital role in the regulation of light in buildings,vehicles,and aircrafts.There is a need for windows with switchable optical properties to prevent or attenuate damage or interference to the human eye and light-sensitive instruments by inappropriate optical radiation.In this context,liquid crystals(LCs),owing to their rich responsiveness and unique optical properties,have been considered among the best candidates for advanced light protection materials.In this review,we provide an overview of advances in research on LC-based methods for protection against light.First,we introduce the characteristics of different light sources and their protection requirements.Second,we introduce several classes of light modulation principles based on liquid crystal materials and demonstrate the feasibility of using them for light protection.In addition,we discuss current light protection strategies based on liquid crystal materials for different applications.Finally,we discuss the problems and shortcomings of current strategies.We propose several suggestions for the development of liquid crystal materials in the field of light protection.
基金The National Key R&D Program of China under contract No.2018YFD0900906the National Natural Science Foundation of China under contract No.31602157+1 种基金the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory under contract No.GML2019ZD0605the Central Public-Interest Scientific Institution Basal Research Fund under contract Nos 2020TD05 and 2021SD01。
文摘Long-term variations in population structure,growth,mortality,length at median sexual maturity,and exploitation rate of threadfin bream(Nemipterus virgatus)are reported based on bottom trawl survey data collected during 1960-2012 in the Beibu Gulf,South China Sea.Laboratory-based analyses were conducted on 16791 individuals collected quarterly in eight different sampling years.Average body length,estimated asymptotic length,and percentage of large individuals have decreased significantly with the growth of marine catch and fishing power,indicating individual miniaturization of this fish species.Estimated exploitation rates indicate that the N.virgatus stock in the Beibu Gulf was moderately exploited in 1960 and 1962 and overexploited after 1992.This stock was taking a good turn in status in 2012,with the lowest exploitation rate since 1992 and ceased downward trend in length indexes.These results suggest that management measures to reduce fishing pressure may have a positive influence on the biological characteristics of this commercial fish species.Biological characteristics of most commercial fish species have phenotypic plasticity and might change over years in response to fisheries management.Therefore,attentions should be paid on variations in fish biological characteristics,when evaluating the effectiveness of current measures to control the total catch for all fisheries.
基金National Key Research and Development Program of China(2022YFA1402404)National Natural Science Foundation of China(92161201,T2221003,12104221,12104220,12274208,12025404,12004174,91961101,61822403,11874203,and 12374043)+1 种基金Natural Science Foundation of Jiangsu Province(BK20230079)Fundamental Research Funds for the Central Universities(020414380192 and 2024300432)。
文摘Kagome lattice,characterized by two-dimensional honeycomb network of corner-sharing triangles[1],presents flat bands,Dirac cones,and van Hove singularities(VHSs),which have been theoretically predicted and experimentally observed[2-4].When combined with spin-orbit coupling(SOC)and magnetism,novel properties have emerged.Although kagome materials vary,most of their strong interlayer interactions make the synthesized crystals not layered,and the properties deviating from the raw two-dimensional kagome lattices.These crystals are difficult to fabricate into thin devices and to tune the physical properties of the materials using gate voltage.
基金supported by the Natural Science Foundation of China(Nos.51971137,11875192,and U1930101)China Postdoctoral Science Foundation(2019M650047)+1 种基金the Independent Innovation Fund of Tianjin University(2020XZY-0016)for their supportsupport of the National Natural Science Foundation of China(81871124)。
文摘Low photothermal conversion efficiency restricts the antibacterial application of photothermal materials.In this work,two-dimensional carbon nanosheets(2D C)were prepared and decorated with Cu nanoparticles(2D C/Cu)by using a simple soluble salt template method combined with ultrasonic exfoliation.The photothermal conversion efficiency of 2 D C/Cu system can be optimized by changing the content of Cu nanoparticles,where the 2D C/Cu2 showed the best photothermal conversion efficiency(á)of 65.05%under 808 nm near-infrared light irradiation.In addition,the photothermal performance can affect the release behavior of Cu ions.This superior photothermal property combined with released Cu ions can endow this 2D hybrid material with highly efficient antibacterial efficacy of 99.97%±0.01%,99.96%±0.01%,99.97%±0.01%against Escherichia coli,Staphylococcus aureus,and methicillin-resistant Staphylococcus aureus,respectively,because of the synergetic effect of photothermy and ion release.In addition,this 2D hybrid system exhibited good cytocompatibility.Hence,this study provides a novel strategy to enhance the photothermal performance of 2D materials and thus will be beneficial for development of antibiotics-free antibacterial materials with safe and highly efficient bactericidal activity.
基金supported by the National Natural Science Foundation of China (21227804, 21390414, 61378062, 21505148)National Key Research and Development Program (2016YFA0400902)the Natural Science Foundation of Shanghai (15ZR1448400, 14ZR1448000)
文摘Stimulated emission depletion(STED) microscope is one of the most prominent super-resolution bio-imaging instruments, which holds great promise for ultrahigh-resolution imaging of cells. To construct a STED microscope, it is challenging to realize temporal synchronization between the excitation pulses and the depletion pulses. In this study, we present a simple and low-cost method to achieve pulse synchronization by using a condensed fluorescent dye as a depletion indicator. By using this method, almost all the confocal microscopes can be upgraded to a STED system without losing its original functions. After the pulse synchronization,our STED system achieved sub-100-nm resolution for fluorescent nanospheres and single-cell imaging.
基金supported by the National Natural Science Foundation of China(Nos.51773231,81572726,and 82102977)Science and Technology Planning Project of Shenzhen Municipality(JCYJ20190807160801664,China)。
文摘Biofilms are closely associated with the tough healing and dysfunctional inflammation of chronic wounds.Photothermal therapy(PTT)emerged as a suitable alternative which could destroy the structure of biofilms with local physical heat.However,the efficacy of PTT is limited because the excessive hyperthermia could damage surrounding tissues.Besides,the difficult reserve and delivery of photothermal agents makes PTT hard to eradicate biofilms as expectation.Herein,we present a GelMA-EGF/Gelatin-MPDA-LZM bilayer hydrogel dressing to perform lysozyme-enhanced PTT for biofilms eradication and a further acceleration to the repair of chronic wounds.Gelatin was used as inner layer hydrogel to reserve lysozyme(LZM)loaded mesoporous polydopamine(MPDA)(MPDA-LZM)nanoparticles,which could rapidly liquefy while temperature rising so as to achieve a bulk release of nanoparticles.MPDA-LZM nanoparticles serve as photothermal agents with antibacterial capability,could deeply penetrate and destroy biofilms.In addition,the outer layer hydrogel consisted of gelatin methacryloyl(GelMA)and epidermal growth factor(EGF)promoted wound healing and tissue regeneration.It displayed remarkable efficacy on alleviating infection and accelerating wound healing in vivo.Overall,the innovative therapeutic strategy we came up with has significant effect on biofilms eradication and shows promising application in promoting the repair of clinical chronic wounds.
基金the National Natural Science Foundation of China(Grant Nos.51771130,51531004,and 51422104)the Tianjin youth talent support program+1 种基金the Tianjin Natural Science Funds for Distinguished Young(Grant No.17JCJQJC44300)the Tianjin Science and Technology Support Project(Grant No.17ZXCLGX00060)。
文摘To synthesize graphene economically and efficiently,as well as to improve the interface bonding between graphene and metal and to recede the aggregation issue of graphene,in this work,an easy and scalable bottom-up strategy for the mass production of metal nanoparticles modified graphene nanoplates(GNPs)was proposed.Cu nanoparticles modified GNPs(Cu-GNPs)and Ni nanoparticles modified GNPs(Ni-GNPs)were fabricated through this method,and then compounded with Al via ball milling technique.The asobtained Ni-GNPs/Al composite showed simultaneously improved strength and toughness compared with unreinforced Al,while the Cu-GNPs/Al composite presented a greater strengthening effect.The microstructure and interface of the two composites were carefully characterized and investigated to reveal the difference.First principle study was also adopted to explore the binding energy of different interface structures.This study could provide new insights into the fabrication of GNPs and the control of interface in GNPs/Al composites.
基金supported by the National Natural Science Foundation of China(81773888,U1903126,81902152,81473320)the Fund of Guangdong Science and Technology Department(2016A020226024)+1 种基金the Fund of Guangzhou Science and Technology Program(201707010048)the Fund of Construction of High Level Universities in Guangzhou Medical University(Nanshan Scholars Program and Academic Backbone Program).
文摘Exosomes play critical roles in regulating various physiological and pathological processes,including immune stimulation,immune suppression,cardiovascular diseases,and cancers.Recent studies show that exosomes that transport specific microRNAs(miRNAs)are involved in tumor development.However,the molecular mechanism by which tumor invasion and migration are regulated by exosomes from non-small cell lung cancer(NSCLC)is not well understood.Here,we show that exosomes shuttling low levels of miR-34c-3p are involved in NSCLC progression.Our results showed that exosomes derived from NSCLC cells carrying low levels of miR-34c-3p could be transported into the cytoplasm of NSCLC cells and accelerate NSCLC invasion and migration by upregulating integrinα2β1.A luciferase assay revealed that integrinα2β1 was the direct target of miR-34c-3p,and overexpression of integrinα2β1 could promote the invasion and migration of NSCLC cells.The analysis of exosomes derived from clinical serum samples indicated that the expression of miR-34c-3p was significantly downregulated in exosomes from NSCLC patients compared with that of normal controls.A549-derived exosomes promoted NSCLC cells lung metastases in vivo.Exosomes shuttling low levels of miR-34c-3p were associated with the progression of NSCLC in vitro and in vivo.Our data demonstrate that exosomes shuttling low levels of miR-34c-3p can accelerate the invasion and migration of NSCLC by upregulating integrinα2β1.MiR-34c-3p can be a diagnostic and prognostic marker for NSCLC.High expression of integrinα2β1 is positively related to the migration and metastasis of NSCLC cells.
