Hepatocellular carcinoma(HCC)is one of the common most malignant tumors.This study aimed to determine the in vitro and in vivo anticancer activity of cordycepin and elucidate its mechanism of action.The results of in ...Hepatocellular carcinoma(HCC)is one of the common most malignant tumors.This study aimed to determine the in vitro and in vivo anticancer activity of cordycepin and elucidate its mechanism of action.The results of in vitro and in vivo studies revealed that cordycepin inhibited proliferation and migration in HepG-2 cells and inhibited the growth of HepG-2 xenograft-bearing nude mice by inducing apoptosis.Transcriptome sequencing analysis revealed a total of 403 differential genes,which revealed that cordycepin may play an anti-HCC role by regulating Hippo signaling pathway.The regulatory effects of cordycepin on the Hippo signaling pathway was further investigated using a YAP1 inhibitor.The results demonstrated that cordycepin upregulated the expression of MST1 and LAST1,and subsequently inhibited YAP1,which activated the Hippo signaling pathway.This in turn downregulated the expression of GBP3 and ETV5,and subsequently inhibited cell proliferation and migration.Additionally,YAP1 regulated the expression of Bax and Bcl-2,regulated the mitochondrial apoptotic pathway,and induced apoptosis by upregulating the expression of the caspase-3 protein.In summary,this study reveals that cordycepin exerts its anti-hepatocarcinoma effect through regulating Hippo signaling pathway,and GBP3 and ETV5 may be potential therapeutic targets for hepatocarcinoma.展开更多
To gain further understanding of the luminescence properties of multiquantum wells and the factors affecting them on a microscopic level,cathodoluminescence combined with scanning transmission electron microscopy and ...To gain further understanding of the luminescence properties of multiquantum wells and the factors affecting them on a microscopic level,cathodoluminescence combined with scanning transmission electron microscopy and spectroscopy was used to measure the luminescence of In_(0.15)Ga_(0.85)N five-period multiquantum wells.The lattice-composition-energy relationship was established with the help of energy-dispersive x-ray spectroscopy,and the bandgaps of In_(0.15)Ga_(0.85)N and GaN in multiple quantum wells were extracted by electron energy loss spectroscopy to understand the features of cathodoluminescence spectra.The luminescence differences between different periods of multiquantum wells and the effects of defects such as composition fluctuation and dislocations on the luminescence of multiple quantum wells were revealed.Our study establishing the direct relationship between the atomic structure of In_(x)Ga_(1-x)N multiquantum wells and photoelectric properties provides useful information for nitride applications.展开更多
Due to its high theoretical capacity(820 mAh g^(−1)),low standard electrode potential(−0.76 V vs.SHE),excellent stability in aqueous solutions,low cost,environmental friendliness and intrinsically high safety,zinc(Zn)...Due to its high theoretical capacity(820 mAh g^(−1)),low standard electrode potential(−0.76 V vs.SHE),excellent stability in aqueous solutions,low cost,environmental friendliness and intrinsically high safety,zinc(Zn)-based batteries have attracted much attention in developing new energy storage devices.In Zn battery system,the battery performance is significantly affected by the solid electrolyte interface(SEI),which is controlled by electrode and electrolyte,and attracts dendrite growth,electrochemical stability window range,metallic Zn anode corrosion and passivation,and electrolyte mutations.Therefore,the design of SEI is decisive for the overall performance of Zn battery systems.This paper summarizes the formation mechanism,the types and characteristics,and the characterization techniques associated with SEI.Meanwhile,we analyze the influence of SEI on battery performance,and put forward the design strategies of SEI.Finally,the future research of SEI in Zn battery system is prospected to seize the nature of SEI,improve the battery performance and promote the large-scale application.展开更多
Co Fe2O4-graphene nanosheets(Co Fe2O4-GNSs) were synthesized through an ultrasonic method, and their electrochemical performances as Li-ion battery electrode were improved by annealing processes. The nanocomposites ob...Co Fe2O4-graphene nanosheets(Co Fe2O4-GNSs) were synthesized through an ultrasonic method, and their electrochemical performances as Li-ion battery electrode were improved by annealing processes. The nanocomposites obtained at 350 °C maintained a high specific capacity of 1,257 m Ah g-1even after 200 cycles at 0.1 A g-1. Furthermore,the obtained materials also have better rate capability, and it can be maintained to 696, 495, 308, and 254 m Ah g-1at 1, 2,5, and 10 A g-1, respectively. The enhancements realized in the reversible capacity and cyclic stability can be attributed to the good improvement in the electrical conductivity achieved by annealing at appropriate temperature, and the electrochemical nature of Co Fe2O4 and GNSs during discharge–charge processes.展开更多
Three-dimensional(3D) flower-like Co–Al layered double hydroxide(Co–Al-LDH) architectures composed of atomically thin nanosheets were successfully synthesized via a hydrothermal method in a mixed solvent of water an...Three-dimensional(3D) flower-like Co–Al layered double hydroxide(Co–Al-LDH) architectures composed of atomically thin nanosheets were successfully synthesized via a hydrothermal method in a mixed solvent of water and butyl alcohol. Owing to the unique hierarchical structure and modification by butyl alcohol, the electrochemical stability and the charge/mass transport of the Co–Al-LDHs was improved. When used in supercapacitors, the obtained Co–Al-LDHs deliver a high specific capacitance of 838 Fg^(-1) at a current density of 1 Ag^(-1)and excellent rate performance(753 Fg^(-1) at 30 Ag^(-1) and 677 Fg^(-1) at 100 Ag^(-1)), as well as excellent cycling stability with 95% retention of the initial capacitance even after 20,000 cycles at a current density of 5 Ag^(-1). This work provides a promising alternative strategy to enhance the electrochemical properties of supercapacitors.展开更多
Carbon-and silica-based nanomaterials possess a set of merits including large surface area,good structural stability,diversified morphology,adjustable structure,and biocompatibility.These outstanding features make the...Carbon-and silica-based nanomaterials possess a set of merits including large surface area,good structural stability,diversified morphology,adjustable structure,and biocompatibility.These outstanding features make them widely applied in different fields.However,limited by the surface free energy effect,the current studies mainly focus on the symmetric structures,such as nanospheres,nanoflowers,nanowires,nanosheets,and core-shell structured composites.By comparison,the asymmetric structure with ingenious adjustability not only exhibits a larger effective surface area accompanied with more active sites,but also enables each component to work independently or corporately to harness their own merits,thus showing the unusual performances in some specific applications.The current review mainly focuses on the recent progress of design principles and synthesis methods of asymmetric carbon-and silica-based nanomaterials,and their applications in energy storage,catalysis,and biomedicine.Particularly,we provide some deep insights into their unique advantages in related fields from the perspective of materials’structure-performance relationship.Furthermore,the challenges and development prospects on the synthesis and applications of asymmetric carbon-and silica-based nanomaterials are also presented and highlighted.展开更多
HEMANGIOBLASTOMA（HB）,a kind of benign tumor with uncertain histogenesis,is Characterized by the presence of stromal cells（SCs）and a rich vascular component.1 It occurs sporadi cally,
BACKGROUND： How to induce endogenous neural stem cells （NSCs） to differentiate into needed neural cell types is a hot spot of current researches. OBJECTIVE： To compare differences between fetal bovine serum and Ch...BACKGROUND： How to induce endogenous neural stem cells （NSCs） to differentiate into needed neural cell types is a hot spot of current researches. OBJECTIVE： To compare differences between fetal bovine serum and Chinese herbal formula Naoluoxintong serum supplementation for inducing proliferation and differentiation in rat embryonic NSCs. DESIGN, TIME AND SETTING： An in vitro, serum pharmacology, comparative, observation study was performed from March to September in 2008 at the Laboratory of Neurodegenerative Diseases, College of Life Science in University of Science and Technology of China, the Key Laboratory Breeding Base of Acupuncture Foundation and Technology in Anhui University of Traditional Chinese Medicine, the Anhui Province Key Laboratory of R ＆ D of Chinese Medicine, and at the Level 3 Laboratory of Molecular Biology of the State Administration of Traditional Chinese Medicine. MATERIALS： The Chinese herbal formula Naoluoxintong was produced by Radix Astragali, Radix Notoginseng, Rhizoma Chuanxiong, Scolopendra at Anhui University of Traditional Chinese Medicine. Mouse anti-rat nestin, gliat fibrillary acidic protein, and galactocerebroside monoclonal antibodies, as well as rabbit anti-neuron-specific enolase polyclonal antibody were produced by Chemicon, Billerica, MA, USA. METHODS： Wistar rats aged 3 months were intragastrically infused with Naoluoxintong. Wistar rat embryonic NSCs （passage 8） were induced to proliferate and differentiate using 10% fetal bovine serum, 10% Naoluoxintong serum, and 10% rat serum. MAIN OUTCOME MEASURES： Phenotypic changes in cultured cells were detected using phase contrast microscopy, and cell proliferation and differentiation were observed using immunofluorescence staining. RESULTS： Proliferation and differentiation of embryonic NSCs was induced by three different types of blood serum. Although the differentiation time course with Nao/uoxintongserum was later than with the other two methods, the differentiated cells were morphologically similar to mature neurons to a greater extent. CONCLUSION： Nao/uoxintong serum supplementation induced differentiation of NSCs into neuronal-like cells and stimulated neuronal maturation.展开更多
ZnO thin films were deposited on the substrates of （100） γ-LiAlO2 at 400,550 and 700℃ using pulsed laser deposition （PLD） with the fixed oxygen pressure of 20 Pa, respectively. When the substrate temperature is ...ZnO thin films were deposited on the substrates of （100） γ-LiAlO2 at 400,550 and 700℃ using pulsed laser deposition （PLD） with the fixed oxygen pressure of 20 Pa, respectively. When the substrate temperature is 400℃, the grain size of the film is less than 1μm observed by Leitz microscope and measured by X-ray diffraction （XRD）. As the substrate temperature increases to 550℃, highly-preferred c-orientation and high-quality ZnO film can be attained.While the substrate temperature rises to 700℃, more defects appears on the surface of film and the ZnO films become polycrystalline again possibly because more Li of the substrate diffused into the ZnO film at high substrate temperature. The photoluminescence （PL） spectra of ZnO films at room temperature show the blue emission peaks centered at 430 nm. We suggest that the blue emission corresponds to the electron transition from the level of interstitial Zn to the valence band. Meanwhile, the films grown on γ-LiAl02 （LAO） exhibit green emission centered at 540 nm, which seemed to be ascribed to excess zinc and/or oxygen vacancy in the ZnO films caused by diffusion of Li from the substrates into the films during the deposition.展开更多
In this study,two dimensional unsteady flows of cylinder and cylinder with additional fairing close to a free surface were numerically investigated.The governing momentum equations were solved by using the Semi Implic...In this study,two dimensional unsteady flows of cylinder and cylinder with additional fairing close to a free surface were numerically investigated.The governing momentum equations were solved by using the Semi Implicit Method for Pressure Linked Equations(SIMPLE).The Volume of Fluid(VOF)method applied to simulate a free surface.Non-uniform grid structures were used in the simulation with denser grids near the cylinder.Under the conditions of Reynolds number 150624,271123,210874 and 331373,the cylinders were simulated with different depths of invasion.It was shown that the flow characteristics were influenced by submergence depth and Reynolds numbers.When the cylinder close to the free surface,the drag coefficient,lift coefficient and Strouhal numbers will increase due to the effect of free liquid surface on vortex shedding.With additional fairing,can effectively reduce the influence of the free surface on the drag coefficient.Fairing will reduce lift coefficient at high Reynolds numbers,but increase lift coefficient when Reynolds numbers are small.Fairing can effectively reduce Strouhal numbers,thus can well suppress the vortex induced vibration.展开更多
Due to the amphiphilic nature of phospholipids in the cell membrane,the amphipathicity of the nanomedicine plays a crucial role in the endocytosis.However,limited biological characterization methods restrict the study...Due to the amphiphilic nature of phospholipids in the cell membrane,the amphipathicity of the nanomedicine plays a crucial role in the endocytosis.However,limited biological characterization methods restrict the study of the state of nanoparticles with different amphiphilicities on cell membranes.The understanding of interaction of amphiphilic particle with cell membrane is still lacking.Herein,by combining the dissipative particle dynamics(DPD)with the framework construction of mesoporous silica nanoparticles(MSNs),we demonstrate the enhanced endocytosis induced by the hydrophobicity.DPD results confirm that the presence of hydrophobic groups on the surface of nanoparticles can disturb the integrity of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine(POPC)membrane and induce activation of phospholipids to a higher energy level,thereby facilitating the wrapping of nanoparticles.To validate the simulation findings,uniform MSNs with hydrophilic pure silica framework and two types of amphiphilic MSNs with varying hydrophilic organic groups in the framework are rationally synthesized by using different silane precursors.The obtained three kinds of MSNs show similar diameter(~100 nm)and mesopores(~2 nm),but distinct hydrophobicity/hydrophilicity ratio.The phenyl-bridged MSN with a carbon content of 27.1%exhibits enhanced cellular uptake,consistent with the theoretical simulation results.This work sheds light on how the surface amphipathicity influences endocytosis through the interaction with cell membrane.展开更多
Inconvenient dual-laser irradiation and tumor hypoxic environment as well as limited judgment of treating region have impeded the development of combined photothermal and photodynamic therapies(PTT and PDT).Herein,Bi2...Inconvenient dual-laser irradiation and tumor hypoxic environment as well as limited judgment of treating region have impeded the development of combined photothermal and photodynamic therapies(PTT and PDT).Herein,Bi2Se3@AIPH nanoparticles(NPs)are facilely developed to overcome these problems.Through a one-step method,free radical generator(AIPH)and phase transition material(lauric acid,LA,44-46°C)are encapsulated in hollow bismuth selenide nanoparticles(Bi2Se3 NPs).Under a single 808-nm laser irradiation at the tumor area,hyperthermia produced by Bi2Se3 not only directly leads to cell death,but also promotes AIPH release by melting LA and triggers free radical generation,which could further eradicate tumor cells in hypoxic environments.Moreover,Bi2Se3 with high X-ray attenuation coefficient endows the NPs with high computed tomography(CT)imaging capability,which is important for treating area determination.The results exhibit that Bi2Se3@AIPH NPs possesses 31.2%photothermal conversion efficiency for enhanced PTT,ideal free radical generation for oxygen-independent PDT,and 37.77 HU mL mg?1 X-ray attenuation coefficient for CT imaging with high quality.Most importantly,the tumor growth inhibition rate by synergistic PTT,PDT,and following immunotherapy is 99.6%,and even one tumor disappears completely,which demonstrates excellent cascaded synergistic effect of Bi2Se3@AIPH NPs for the tumor therapy.展开更多
This paper develops a deep learning classification method with fully-connected 8-layers characteristics to classification of coastal wetland based on CHRIS hyperspectral image. The method combined spectral feature and...This paper develops a deep learning classification method with fully-connected 8-layers characteristics to classification of coastal wetland based on CHRIS hyperspectral image. The method combined spectral feature and multi-spatial texture feature information has been applied in the Huanghe(Yellow) River Estuary coastal wetland.The results show that:(1) Based on testing samples, the DCNN model combined spectral feature and texture feature after K-L transformation appear high classification accuracy, which is up to 99%.(2) The accuracy by using spectral feature with all the texture feature is lower than that using spectral only and combing spectral and texture feature after K-L transformation. The DCNN classification accuracy using spectral feature and texture feature after K-L transformation was up to 99.38%, and the outperformed that of all the texture feature by 4.15%.(3) The classification accuracy of the DCNN method achieves better performance than other methods based on the whole validation image, with an overall accuracy of 84.64% and the Kappa coefficient of 0.80.(4) The developed DCNN model classification algorithm ensured the accuracy of all types is more balanced, and it also greatly improved the accuracy of tidal flat and farmland, while kept the classification accuracy of main types almost invariant compared to the shallow algorithms. The classification accuracy of tidal flat and farmland is up to 79.26% and 56.72%respectively based on the DCNN model. And it improves by about 2.51% and 10.6% compared with that of the other shallow classification methods.展开更多
Porous Zn–Sn–O nanocubes with a uniform size were synthesized through a facile aqueous solution route combined with subsequent thermal treatment. The chemical composition, morphology, and microstructure of Zn–Sn–O...Porous Zn–Sn–O nanocubes with a uniform size were synthesized through a facile aqueous solution route combined with subsequent thermal treatment. The chemical composition, morphology, and microstructure of Zn–Sn–O nanocubes, which have significant effects on the lithium storage performances, were easily tuned by adjusting the calcination temperature in preparation processes of ZnSn(OH)6solid nanocubes. Further studies revealed that porous Zn–Sn–O nanocubes prepared at 600 °C exhibited a good rate capability and a high reversible capacity of 700 m Ah g^(-1)at a current density of 200 m Ag^(-1)after 50 cycles, which may be a great potential as anode materials in Lithium-ion batteries.展开更多
Opto–electromechanical coupling at the nanoscale is an important topic in new scientific studies and technical applications. In this work, the optically manipulated electromechanical behaviors of individual cadmium s...Opto–electromechanical coupling at the nanoscale is an important topic in new scientific studies and technical applications. In this work, the optically manipulated electromechanical behaviors of individual cadmium sulfide(CdS) nanowires are investigated by a customer-built optical holder inside transmission electron microscope, wherein in situ electromechanical resonance took place in conjunction with photo excitation. It is found that the natural resonance frequency of the nanowire under illumination becomes considerably lower than that under darkness. This redshift effect is closely related to the wavelength of the applied light and the diameter of the nanowires. Density functional theory(DFT) calculation shows that the photoexcitation leads to the softening of CdS nanowires and thus the redshift of natural frequency, which is in agreement with the experimental results.展开更多
The membrane-associated c-type cytochromes(c-Cyts) have been well known as the key enzymes mediating extracellular electron transfer to terminal electron acceptors, resulting in biogeochemical elemental transformation...The membrane-associated c-type cytochromes(c-Cyts) have been well known as the key enzymes mediating extracellular electron transfer to terminal electron acceptors, resulting in biogeochemical elemental transformation, contaminant degradation, and nutrient cycling. Although c-Cyts-mediated metal reduction or oxidation have been mainly investigated with the purified proteins of metal reducing/oxidizing bacteria, the in vivo behavior of c-Cyts is still unclear, given the difficulty in measuring the proteins of intact cells. Fortunately, the in situ spectroscopy would be ideal for measuring the reaction kinetics of c-Cyts in intact cells under noninvasive physiological conditions. It can also help the establishment of kinetic/thermodynamic models of extracellular electron transfer processes, which are essential to understand the electron transfer mechanisms at the molecular scale. This review briefly summarizes the current advances in spectral methods for examining the c-Cyts in intact cells of dissimilatory metal reducing bacteria and Fe(Ⅱ)-oxidizing bacteria.展开更多
Iron oxidation is a prevalent and important biogeochemical process in paddy soil,but little is known about whether and how microbially mediated iron oxidation is coupled with carbon assimilation,particularly under mic...Iron oxidation is a prevalent and important biogeochemical process in paddy soil,but little is known about whether and how microbially mediated iron oxidation is coupled with carbon assimilation,particularly under microaerobic conditions.Here,we investigated kinetics of CO_2 assimilation and Fe(Ⅱ)oxidation in an incubation experiment with paddy soil under suboxic conditions,and profiled the associated microbial community using DNA-stable isotope probing and 16S r RNA gene-based sequencing.The results showed that CO_2 assimilation and Fe(II)oxidation in the gradient tubes were predominantly mediated by the microbes enriched in the paddy soil,primarily Azospirillum and Magnetospirillum,as their relative abundances were higher in the^( 13)C heavy fractions compared to^( 12)C heavy fractions.This study provided direct evidence of chemoautotrophic microaerophiles linking iron oxidation and carbon assimilation at the oxic–anoxic interface in the paddy soil ecosystem.展开更多
Hydroxypropyltrimethyl ammonium chloride chitosan(HACC)and hydroxypropyltrimethyl ammonium chloride fully deacetylated chitosan(De-HACC)were synthesized with various degrees of substitution by altering the ratio of ch...Hydroxypropyltrimethyl ammonium chloride chitosan(HACC)and hydroxypropyltrimethyl ammonium chloride fully deacetylated chitosan(De-HACC)were synthesized with various degrees of substitution by altering the ratio of chitosan to glycidyl trimethyl-ammonium chloride(GTMAC).The effects of the quaternary ammonium degree and the acetyl group of these polymers on immunostimulatory activities were detected in RAW 264.7 cells.The expression levels of nitrogen oxide(NO),interleukin-6(IL-6)and tumor necrosis factor(TNF-α)were compared.Results show that the removal of acetyl groups in chitosan obviously improved the degree of substitution of quaternary ammonium salts.In addition,HACC and De-HACC were capable of promoting immunological activity in a substitution-dependent manner;HACC was positively correlated,and De-HACC was negatively correlated.Among tested ratios,HACC-30%and De-HACC-54%performed better than the others,and De-HACC-54%performed the best.Generally,quaternized chitosan possesses immunostimulatory activity,which is related to the degree of quaternization and the acetyl group.展开更多
基金supported by the National Natural Science Foundation of China(81503187)。
文摘Hepatocellular carcinoma(HCC)is one of the common most malignant tumors.This study aimed to determine the in vitro and in vivo anticancer activity of cordycepin and elucidate its mechanism of action.The results of in vitro and in vivo studies revealed that cordycepin inhibited proliferation and migration in HepG-2 cells and inhibited the growth of HepG-2 xenograft-bearing nude mice by inducing apoptosis.Transcriptome sequencing analysis revealed a total of 403 differential genes,which revealed that cordycepin may play an anti-HCC role by regulating Hippo signaling pathway.The regulatory effects of cordycepin on the Hippo signaling pathway was further investigated using a YAP1 inhibitor.The results demonstrated that cordycepin upregulated the expression of MST1 and LAST1,and subsequently inhibited YAP1,which activated the Hippo signaling pathway.This in turn downregulated the expression of GBP3 and ETV5,and subsequently inhibited cell proliferation and migration.Additionally,YAP1 regulated the expression of Bax and Bcl-2,regulated the mitochondrial apoptotic pathway,and induced apoptosis by upregulating the expression of the caspase-3 protein.In summary,this study reveals that cordycepin exerts its anti-hepatocarcinoma effect through regulating Hippo signaling pathway,and GBP3 and ETV5 may be potential therapeutic targets for hepatocarcinoma.
基金Project supported by the National Key R&D Program of China (Grant No. 2019YFA0708202)the National Natural Science Foundation of China (Grant Nos. 11974023, 52021006, 61974139, 12074369, and 12104017)+1 种基金the “2011 Program” from the Peking–Tsinghua–IOP Collaborative Innovation Center of Quantum Matterthe Youth Supporting Program of Institute of Semiconductors
文摘To gain further understanding of the luminescence properties of multiquantum wells and the factors affecting them on a microscopic level,cathodoluminescence combined with scanning transmission electron microscopy and spectroscopy was used to measure the luminescence of In_(0.15)Ga_(0.85)N five-period multiquantum wells.The lattice-composition-energy relationship was established with the help of energy-dispersive x-ray spectroscopy,and the bandgaps of In_(0.15)Ga_(0.85)N and GaN in multiple quantum wells were extracted by electron energy loss spectroscopy to understand the features of cathodoluminescence spectra.The luminescence differences between different periods of multiquantum wells and the effects of defects such as composition fluctuation and dislocations on the luminescence of multiple quantum wells were revealed.Our study establishing the direct relationship between the atomic structure of In_(x)Ga_(1-x)N multiquantum wells and photoelectric properties provides useful information for nitride applications.
基金This research was supported by the Fundamental Research Funds for the Central Universities(0515022GH0202253 and 0515022SH0201253).
文摘Due to its high theoretical capacity(820 mAh g^(−1)),low standard electrode potential(−0.76 V vs.SHE),excellent stability in aqueous solutions,low cost,environmental friendliness and intrinsically high safety,zinc(Zn)-based batteries have attracted much attention in developing new energy storage devices.In Zn battery system,the battery performance is significantly affected by the solid electrolyte interface(SEI),which is controlled by electrode and electrolyte,and attracts dendrite growth,electrochemical stability window range,metallic Zn anode corrosion and passivation,and electrolyte mutations.Therefore,the design of SEI is decisive for the overall performance of Zn battery systems.This paper summarizes the formation mechanism,the types and characteristics,and the characterization techniques associated with SEI.Meanwhile,we analyze the influence of SEI on battery performance,and put forward the design strategies of SEI.Finally,the future research of SEI in Zn battery system is prospected to seize the nature of SEI,improve the battery performance and promote the large-scale application.
基金supported by the Program of National Natural Science Foundation of China (21071097, 20901050)National Basic Research Program of China (2014CB239700)+1 种基金Shanghai Nano-Project (12 nm0503502)Minhang District Developing Project
文摘Co Fe2O4-graphene nanosheets(Co Fe2O4-GNSs) were synthesized through an ultrasonic method, and their electrochemical performances as Li-ion battery electrode were improved by annealing processes. The nanocomposites obtained at 350 °C maintained a high specific capacity of 1,257 m Ah g-1even after 200 cycles at 0.1 A g-1. Furthermore,the obtained materials also have better rate capability, and it can be maintained to 696, 495, 308, and 254 m Ah g-1at 1, 2,5, and 10 A g-1, respectively. The enhancements realized in the reversible capacity and cyclic stability can be attributed to the good improvement in the electrical conductivity achieved by annealing at appropriate temperature, and the electrochemical nature of Co Fe2O4 and GNSs during discharge–charge processes.
基金supported by the National Basic Research Program of China(2014CB239702)Research project of environmental protection in Jiangsu province(2016060)Science and Technology Commission of Shanghai Municipality(14DZ2250800)
文摘Three-dimensional(3D) flower-like Co–Al layered double hydroxide(Co–Al-LDH) architectures composed of atomically thin nanosheets were successfully synthesized via a hydrothermal method in a mixed solvent of water and butyl alcohol. Owing to the unique hierarchical structure and modification by butyl alcohol, the electrochemical stability and the charge/mass transport of the Co–Al-LDHs was improved. When used in supercapacitors, the obtained Co–Al-LDHs deliver a high specific capacitance of 838 Fg^(-1) at a current density of 1 Ag^(-1)and excellent rate performance(753 Fg^(-1) at 30 Ag^(-1) and 677 Fg^(-1) at 100 Ag^(-1)), as well as excellent cycling stability with 95% retention of the initial capacitance even after 20,000 cycles at a current density of 5 Ag^(-1). This work provides a promising alternative strategy to enhance the electrochemical properties of supercapacitors.
基金support from the Shuguang Program supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(18SG035)Shanghai Engineering Research Center of Advanced Thermal Functional Materials(Shanghai Polytechnic University).
文摘Carbon-and silica-based nanomaterials possess a set of merits including large surface area,good structural stability,diversified morphology,adjustable structure,and biocompatibility.These outstanding features make them widely applied in different fields.However,limited by the surface free energy effect,the current studies mainly focus on the symmetric structures,such as nanospheres,nanoflowers,nanowires,nanosheets,and core-shell structured composites.By comparison,the asymmetric structure with ingenious adjustability not only exhibits a larger effective surface area accompanied with more active sites,but also enables each component to work independently or corporately to harness their own merits,thus showing the unusual performances in some specific applications.The current review mainly focuses on the recent progress of design principles and synthesis methods of asymmetric carbon-and silica-based nanomaterials,and their applications in energy storage,catalysis,and biomedicine.Particularly,we provide some deep insights into their unique advantages in related fields from the perspective of materials’structure-performance relationship.Furthermore,the challenges and development prospects on the synthesis and applications of asymmetric carbon-and silica-based nanomaterials are also presented and highlighted.
基金Supported by Wannan Medical College Key Research Projects(WK2016Z08)
文摘HEMANGIOBLASTOMA（HB）,a kind of benign tumor with uncertain histogenesis,is Characterized by the presence of stromal cells（SCs）and a rich vascular component.1 It occurs sporadi cally,
基金National Natural Science Foundation of China,No.30873293,30672592Natural Science Foundation of Anhui Province,No.070413125,050430904+1 种基金Dr.Yafang Lü Graduate Research Foundation of Beijing University of Chinese Medicine,No.2004Natural Science Research Fund of Education Department of Anhui Province,No.2006KJ382B
文摘BACKGROUND： How to induce endogenous neural stem cells （NSCs） to differentiate into needed neural cell types is a hot spot of current researches. OBJECTIVE： To compare differences between fetal bovine serum and Chinese herbal formula Naoluoxintong serum supplementation for inducing proliferation and differentiation in rat embryonic NSCs. DESIGN, TIME AND SETTING： An in vitro, serum pharmacology, comparative, observation study was performed from March to September in 2008 at the Laboratory of Neurodegenerative Diseases, College of Life Science in University of Science and Technology of China, the Key Laboratory Breeding Base of Acupuncture Foundation and Technology in Anhui University of Traditional Chinese Medicine, the Anhui Province Key Laboratory of R ＆ D of Chinese Medicine, and at the Level 3 Laboratory of Molecular Biology of the State Administration of Traditional Chinese Medicine. MATERIALS： The Chinese herbal formula Naoluoxintong was produced by Radix Astragali, Radix Notoginseng, Rhizoma Chuanxiong, Scolopendra at Anhui University of Traditional Chinese Medicine. Mouse anti-rat nestin, gliat fibrillary acidic protein, and galactocerebroside monoclonal antibodies, as well as rabbit anti-neuron-specific enolase polyclonal antibody were produced by Chemicon, Billerica, MA, USA. METHODS： Wistar rats aged 3 months were intragastrically infused with Naoluoxintong. Wistar rat embryonic NSCs （passage 8） were induced to proliferate and differentiate using 10% fetal bovine serum, 10% Naoluoxintong serum, and 10% rat serum. MAIN OUTCOME MEASURES： Phenotypic changes in cultured cells were detected using phase contrast microscopy, and cell proliferation and differentiation were observed using immunofluorescence staining. RESULTS： Proliferation and differentiation of embryonic NSCs was induced by three different types of blood serum. Although the differentiation time course with Nao/uoxintongserum was later than with the other two methods, the differentiated cells were morphologically similar to mature neurons to a greater extent. CONCLUSION： Nao/uoxintong serum supplementation induced differentiation of NSCs into neuronal-like cells and stimulated neuronal maturation.
文摘ZnO thin films were deposited on the substrates of （100） γ-LiAlO2 at 400,550 and 700℃ using pulsed laser deposition （PLD） with the fixed oxygen pressure of 20 Pa, respectively. When the substrate temperature is 400℃, the grain size of the film is less than 1μm observed by Leitz microscope and measured by X-ray diffraction （XRD）. As the substrate temperature increases to 550℃, highly-preferred c-orientation and high-quality ZnO film can be attained.While the substrate temperature rises to 700℃, more defects appears on the surface of film and the ZnO films become polycrystalline again possibly because more Li of the substrate diffused into the ZnO film at high substrate temperature. The photoluminescence （PL） spectra of ZnO films at room temperature show the blue emission peaks centered at 430 nm. We suggest that the blue emission corresponds to the electron transition from the level of interstitial Zn to the valence band. Meanwhile, the films grown on γ-LiAl02 （LAO） exhibit green emission centered at 540 nm, which seemed to be ascribed to excess zinc and/or oxygen vacancy in the ZnO films caused by diffusion of Li from the substrates into the films during the deposition.
文摘In this study,two dimensional unsteady flows of cylinder and cylinder with additional fairing close to a free surface were numerically investigated.The governing momentum equations were solved by using the Semi Implicit Method for Pressure Linked Equations(SIMPLE).The Volume of Fluid(VOF)method applied to simulate a free surface.Non-uniform grid structures were used in the simulation with denser grids near the cylinder.Under the conditions of Reynolds number 150624,271123,210874 and 331373,the cylinders were simulated with different depths of invasion.It was shown that the flow characteristics were influenced by submergence depth and Reynolds numbers.When the cylinder close to the free surface,the drag coefficient,lift coefficient and Strouhal numbers will increase due to the effect of free liquid surface on vortex shedding.With additional fairing,can effectively reduce the influence of the free surface on the drag coefficient.Fairing will reduce lift coefficient at high Reynolds numbers,but increase lift coefficient when Reynolds numbers are small.Fairing can effectively reduce Strouhal numbers,thus can well suppress the vortex induced vibration.
基金supported by the National Natural Science Foundation of China(Nos.22075049,22305042,22305041,21875043,22088101,21905052,and 51961145403)the National Key R&D Program of China(No.2018YFA0209401)+4 种基金the Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.22JC1410200)the Natural Science Foundation of Shanghai(Nos.22ZR1478900 and 20490710600)the Shanghai Science and Technology Innovation Action Plan Morning Star Project(Sail Special,Nos.20QA1401200,22YF1402200,and 23YF1401900)the Shanghai Pilot Program for Basic Research-Fudan University(No.22TQ004)the Fundamental Research Funds for the Central Universities(No.20720220010).
文摘Due to the amphiphilic nature of phospholipids in the cell membrane,the amphipathicity of the nanomedicine plays a crucial role in the endocytosis.However,limited biological characterization methods restrict the study of the state of nanoparticles with different amphiphilicities on cell membranes.The understanding of interaction of amphiphilic particle with cell membrane is still lacking.Herein,by combining the dissipative particle dynamics(DPD)with the framework construction of mesoporous silica nanoparticles(MSNs),we demonstrate the enhanced endocytosis induced by the hydrophobicity.DPD results confirm that the presence of hydrophobic groups on the surface of nanoparticles can disturb the integrity of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine(POPC)membrane and induce activation of phospholipids to a higher energy level,thereby facilitating the wrapping of nanoparticles.To validate the simulation findings,uniform MSNs with hydrophilic pure silica framework and two types of amphiphilic MSNs with varying hydrophilic organic groups in the framework are rationally synthesized by using different silane precursors.The obtained three kinds of MSNs show similar diameter(~100 nm)and mesopores(~2 nm),but distinct hydrophobicity/hydrophilicity ratio.The phenyl-bridged MSN with a carbon content of 27.1%exhibits enhanced cellular uptake,consistent with the theoretical simulation results.This work sheds light on how the surface amphipathicity influences endocytosis through the interaction with cell membrane.
基金supported by the National Natural Science Foundation of China(Nos.51433004 and 51773096)Natural Science Foundation of Tianjin(No.17JCZDJC33500)PCSIRT(IRT1257).
文摘Inconvenient dual-laser irradiation and tumor hypoxic environment as well as limited judgment of treating region have impeded the development of combined photothermal and photodynamic therapies(PTT and PDT).Herein,Bi2Se3@AIPH nanoparticles(NPs)are facilely developed to overcome these problems.Through a one-step method,free radical generator(AIPH)and phase transition material(lauric acid,LA,44-46°C)are encapsulated in hollow bismuth selenide nanoparticles(Bi2Se3 NPs).Under a single 808-nm laser irradiation at the tumor area,hyperthermia produced by Bi2Se3 not only directly leads to cell death,but also promotes AIPH release by melting LA and triggers free radical generation,which could further eradicate tumor cells in hypoxic environments.Moreover,Bi2Se3 with high X-ray attenuation coefficient endows the NPs with high computed tomography(CT)imaging capability,which is important for treating area determination.The results exhibit that Bi2Se3@AIPH NPs possesses 31.2%photothermal conversion efficiency for enhanced PTT,ideal free radical generation for oxygen-independent PDT,and 37.77 HU mL mg?1 X-ray attenuation coefficient for CT imaging with high quality.Most importantly,the tumor growth inhibition rate by synergistic PTT,PDT,and following immunotherapy is 99.6%,and even one tumor disappears completely,which demonstrates excellent cascaded synergistic effect of Bi2Se3@AIPH NPs for the tumor therapy.
基金The National Natural Science Foundation of China under contract No.61601133 and 41206172the Marine Application System of High Resolution Earth Observation System Major Project
文摘This paper develops a deep learning classification method with fully-connected 8-layers characteristics to classification of coastal wetland based on CHRIS hyperspectral image. The method combined spectral feature and multi-spatial texture feature information has been applied in the Huanghe(Yellow) River Estuary coastal wetland.The results show that:(1) Based on testing samples, the DCNN model combined spectral feature and texture feature after K-L transformation appear high classification accuracy, which is up to 99%.(2) The accuracy by using spectral feature with all the texture feature is lower than that using spectral only and combing spectral and texture feature after K-L transformation. The DCNN classification accuracy using spectral feature and texture feature after K-L transformation was up to 99.38%, and the outperformed that of all the texture feature by 4.15%.(3) The classification accuracy of the DCNN method achieves better performance than other methods based on the whole validation image, with an overall accuracy of 84.64% and the Kappa coefficient of 0.80.(4) The developed DCNN model classification algorithm ensured the accuracy of all types is more balanced, and it also greatly improved the accuracy of tidal flat and farmland, while kept the classification accuracy of main types almost invariant compared to the shallow algorithms. The classification accuracy of tidal flat and farmland is up to 79.26% and 56.72%respectively based on the DCNN model. And it improves by about 2.51% and 10.6% compared with that of the other shallow classification methods.
基金supported by the National Basic Research Program of China(2014CB239700)the Program of National Natural Science Foundation of China(21501120+1 种基金21371121and 21331004)Science and Technology Commission of Shanghai Municipality(14DZ1205700 and 14DZ2250800)
文摘Porous Zn–Sn–O nanocubes with a uniform size were synthesized through a facile aqueous solution route combined with subsequent thermal treatment. The chemical composition, morphology, and microstructure of Zn–Sn–O nanocubes, which have significant effects on the lithium storage performances, were easily tuned by adjusting the calcination temperature in preparation processes of ZnSn(OH)6solid nanocubes. Further studies revealed that porous Zn–Sn–O nanocubes prepared at 600 °C exhibited a good rate capability and a high reversible capacity of 700 m Ah g^(-1)at a current density of 200 m Ag^(-1)after 50 cycles, which may be a great potential as anode materials in Lithium-ion batteries.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21773303,21872172,51472267,and 51421002)the Chinese Academy of Sciences(Grant Nos.ZDYZ2015-1,XDB30000000,and XDB07030100)
文摘Opto–electromechanical coupling at the nanoscale is an important topic in new scientific studies and technical applications. In this work, the optically manipulated electromechanical behaviors of individual cadmium sulfide(CdS) nanowires are investigated by a customer-built optical holder inside transmission electron microscope, wherein in situ electromechanical resonance took place in conjunction with photo excitation. It is found that the natural resonance frequency of the nanowire under illumination becomes considerably lower than that under darkness. This redshift effect is closely related to the wavelength of the applied light and the diameter of the nanowires. Density functional theory(DFT) calculation shows that the photoexcitation leads to the softening of CdS nanowires and thus the redshift of natural frequency, which is in agreement with the experimental results.
基金funded by the National Natural Science Foundations of China(41522105 and 41571130052)Guangdong Natural Science Funds for Distinguished Young Scholar(2014A030306041)Special Support Program(2016)
文摘The membrane-associated c-type cytochromes(c-Cyts) have been well known as the key enzymes mediating extracellular electron transfer to terminal electron acceptors, resulting in biogeochemical elemental transformation, contaminant degradation, and nutrient cycling. Although c-Cyts-mediated metal reduction or oxidation have been mainly investigated with the purified proteins of metal reducing/oxidizing bacteria, the in vivo behavior of c-Cyts is still unclear, given the difficulty in measuring the proteins of intact cells. Fortunately, the in situ spectroscopy would be ideal for measuring the reaction kinetics of c-Cyts in intact cells under noninvasive physiological conditions. It can also help the establishment of kinetic/thermodynamic models of extracellular electron transfer processes, which are essential to understand the electron transfer mechanisms at the molecular scale. This review briefly summarizes the current advances in spectral methods for examining the c-Cyts in intact cells of dissimilatory metal reducing bacteria and Fe(Ⅱ)-oxidizing bacteria.
基金funded by the National Natural Science Foundations of China(41420104007,41330857,and 41701295)Guangdong Natural Science Funds for Distinguished Young Scholar(2014A030306041)and Special Support Program(2016)
文摘Iron oxidation is a prevalent and important biogeochemical process in paddy soil,but little is known about whether and how microbially mediated iron oxidation is coupled with carbon assimilation,particularly under microaerobic conditions.Here,we investigated kinetics of CO_2 assimilation and Fe(Ⅱ)oxidation in an incubation experiment with paddy soil under suboxic conditions,and profiled the associated microbial community using DNA-stable isotope probing and 16S r RNA gene-based sequencing.The results showed that CO_2 assimilation and Fe(II)oxidation in the gradient tubes were predominantly mediated by the microbes enriched in the paddy soil,primarily Azospirillum and Magnetospirillum,as their relative abundances were higher in the^( 13)C heavy fractions compared to^( 12)C heavy fractions.This study provided direct evidence of chemoautotrophic microaerophiles linking iron oxidation and carbon assimilation at the oxic–anoxic interface in the paddy soil ecosystem.
基金*Supported by Key Deployment Projects of the Marine Science Research Center of Chinese Academy of Sciences(No.COMS2020J04)。
文摘Hydroxypropyltrimethyl ammonium chloride chitosan(HACC)and hydroxypropyltrimethyl ammonium chloride fully deacetylated chitosan(De-HACC)were synthesized with various degrees of substitution by altering the ratio of chitosan to glycidyl trimethyl-ammonium chloride(GTMAC).The effects of the quaternary ammonium degree and the acetyl group of these polymers on immunostimulatory activities were detected in RAW 264.7 cells.The expression levels of nitrogen oxide(NO),interleukin-6(IL-6)and tumor necrosis factor(TNF-α)were compared.Results show that the removal of acetyl groups in chitosan obviously improved the degree of substitution of quaternary ammonium salts.In addition,HACC and De-HACC were capable of promoting immunological activity in a substitution-dependent manner;HACC was positively correlated,and De-HACC was negatively correlated.Among tested ratios,HACC-30%and De-HACC-54%performed better than the others,and De-HACC-54%performed the best.Generally,quaternized chitosan possesses immunostimulatory activity,which is related to the degree of quaternization and the acetyl group.
