Fluorescence-based imaging applications have been benefiting greatly from donor-acceptor(D-A)/donor-π-acceptor(D-π-A)fluorescent probes owing to their intramolecular charge transfer(ICT)nature and self-assembly beha...Fluorescence-based imaging applications have been benefiting greatly from donor-acceptor(D-A)/donor-π-acceptor(D-π-A)fluorescent probes owing to their intramolecular charge transfer(ICT)nature and self-assembly behavior.In this study,we design and synthesize a hydrophilic D-A fluorescent probe,namely CHBA,which would self-assemble into interlaced textures down to nanoscale but disassemble by trace amount of water in fingertip area.Upon finger-pressing,it enables fingerprint imaging and covers level-1/2/3 fingerprint information,wherein the sweat pores can be mapped in both bright field model and fluorescence mode,capable of naked-eye-based similarity analysis for personal identity verification(PIV).Spectroscopic analysis and morphology study show that the working mechanism can be attributed to the selective water-erosion effect on the solid-liquid interphase under physical contact.The sweat pore information can be digitized by polar coordinate conversion,further allowing machine-learning-based analysis for PIV application.The final PIV accuracy reaches 100%for all the involved machine-learning models,with no erroneous judgements.A prototype of PIV system is constructed by integrating CHBA with artificial intelligence hardware,wherein the sweat pore imaging,data processing and the decisionmaking could be run in parallel,suggesting high feasibility in real-world application.展开更多
The exploration of sustainable energy utilization requires the imple-mentation of advanced electrochemical devices for efficient energy conversion and storage,which are enabled by the usage of cost-effective,high-perf...The exploration of sustainable energy utilization requires the imple-mentation of advanced electrochemical devices for efficient energy conversion and storage,which are enabled by the usage of cost-effective,high-performance electro-catalysts.Currently,heterogeneous atomically dispersed catalysts are considered as potential candidates for a wide range of applications.Compared to conventional cata-lysts,atomically dispersed metal atoms in carbon-based catalysts have more unsatu-rated coordination sites,quantum size effect,and strong metal-support interactions,resulting in exceptional catalytic activity.Of these,dual-atomic catalysts(DACs)have attracted extensive attention due to the additional synergistic effect between two adja-cent metal atoms.DACs have the advantages of full active site exposure,high selectiv-ity,theoretical 100%atom utilization,and the ability to break the scaling relationship of adsorption free energy on active sites.In this review,we summarize recent research advancement of DACs,which includes(1)the comprehensive understanding of the synergy between atomic pairs;(2)the synthesis of DACs;(3)characterization meth-ods,especially aberration-corrected scanning transmission electron microscopy and synchrotron spectroscopy;and(4)electrochemical energy-related applications.The last part focuses on great potential for the electrochemical catalysis of energy-related small molecules,such as oxygen reduction reaction,CO_(2) reduction reaction,hydrogen evolution reaction,and N_(2) reduction reaction.The future research challenges and opportunities are also raised in prospective section.展开更多
Objective:To explore which pattern recognition receptors(PRRs)play a key role in the development of hand,foot,and mouth disease(HFMD)by analyzing PRR-associated genes.Methods:We conducted a comparative analysis of PRR...Objective:To explore which pattern recognition receptors(PRRs)play a key role in the development of hand,foot,and mouth disease(HFMD)by analyzing PRR-associated genes.Methods:We conducted a comparative analysis of PRR-associated gene expression in human peripheral blood mononuclear cells(PBMCs)infected with enterovirus 71(EV-A71)which were derived from patients with HFMD of different severities and at different stages.A total of 30 PRR-associated genes were identified as significantly upregulated both over time and across different EV-A71 isolates.Subsequently,ELISA was employed to quantify the expression of the six most prominent genes among these 30 identified genes,specifically,BST2,IRF7,IFI16,TRIM21,MX1,and DDX58.Results:Compared with those at the recovery stage,the expression levels of BST2(P=0.027),IFI16(P=0.016),MX1(P=0.046)and DDX58(P=0.008)in the acute stage of infection were significantly upregulated,while no significant difference in the expression levels of IRF7(P=0.495)and TRIM21(P=0.071)was found between different stages of the disease.The expression levels of BST2,IRF7,IFI16 and MX1 were significantly higher in children infected with single pathogen than those infected with mixed pathogens,and BST2,IRF7,IFI16 and MX1 expression levels were significantly lower in coxsackie B virus(COXB)positive patients than the negative patients.Expression levels of one or more of BST2,IRF7,IFI16,TRIM21,MX1 and DDX58 genes were correlated with PCT levels,various white blood cell counts,and serum antibody levels that reflect disease course of HFMD.Aspartate aminotransferase was correlated with BST2,MX1 and DDX58 expression levels.Conclusions:PRR-associated genes likely initiate the immune response in patients at the acute stage of HFMD.展开更多
Dear Editor,Industrial Internet of things(IIoT) is a typical application of cyberphysical system(CPS). In the IIoT, wireless communication is an inevitable trend to replace the deployment-limited wired transmission fo...Dear Editor,Industrial Internet of things(IIoT) is a typical application of cyberphysical system(CPS). In the IIoT, wireless communication is an inevitable trend to replace the deployment-limited wired transmission for cases with large-scale and mobile devices. However, wireless communication gives rise to critical issues related to physical security, such as malicious detections and attacks [1].展开更多
Tetrahydrofuran(THF) extract of coal tar pitch(CTP) was used instead of blending CTP with pretreated pyrolysis fuel oil to prepare an isotropic pitch precursor with excellent spinnability for general-purpose carbon fi...Tetrahydrofuran(THF) extract of coal tar pitch(CTP) was used instead of blending CTP with pretreated pyrolysis fuel oil to prepare an isotropic pitch precursor with excellent spinnability for general-purpose carbon fibre through bromination-dehydrobromination. The feasibility and effectiveness of synthesising an isotropic pitch precursor derived from THF-soluble(CTP-THFs) is demonstrated in this study.The results show that CTP-THFs contains more light components than CTP;CTP-THFs and CTP monomer proportions were 62.52% and 45.32%, respectively. However, based on comparisons of CTP-THFsBr0 and CTPBr0 characterisations, CTP-THFs exhibits better polycondensation than CTP. Bromination-dehydrobro mination promotes polycondensation of pitch precursors, leading to greater carbon aromaticity in CTP-THFsBr5, CTP-THFsBr10, and CTP-THFsBr15 than that in CTP-THFsBr0 and CTPBr0. CTP-THFsBr5 and CTP-THFsBr10 have excellent spinnability even with softening points as high as 230 ℃. The pericondensed carbon and carbon aromaticity of CTP-THFsBr5 and CTP-THFsBr10 are high owing to the higher degree of polycondensation;however, they still possess a more linear molecular structure. The as-prepared carbon fibre exhibits homogeneity and uniformity, and the mechanical performance is comparable with that of commercial general-purpose carbon fibre products.展开更多
Cancer immunotherapy,a therapeutic approach that inhibits tumors by activating or strengthening anti-tumor immunity,is currently an important clinical strategy for cancer treatment;however,tumors can develop drug resi...Cancer immunotherapy,a therapeutic approach that inhibits tumors by activating or strengthening anti-tumor immunity,is currently an important clinical strategy for cancer treatment;however,tumors can develop drug resistance to immune surveillance,resulting in poor response rates and low therapeutic efficacy.In addition,changes in genes and signaling pathways in tumor cells prevent susceptibility to immunotherapeutic agents.Furthermore,tumors create an immunosuppressive microenvironment via immunosuppressive cells and secrete molecules that hinder immune cell and immune modulator infiltration or induce immune cell malfunction.To address these challenges,smart drug delivery systems(SDDSs)have been developed to overcome tumor cell resistance to immunomodulators,restore or boost immune cell activity,and magnify immune responses.To combat resistance to small molecules and monoclonal antibodies,SDDSs are used to co-deliver numerous therapeutic agents to tumor cells or immunosuppressive cells,thus increasing the drug concentration at the target site and improving efficacy.Herein,we discuss how SDDSs overcome drug resistance during cancer immunotherapy,with a focus on recent SDDS advances in thwarting drug resistance in immunotherapy by combining immunogenic cell death with immunotherapy and reversing the tumor immunosuppressive microenvironment.SDDSs that modulate the interferon signaling pathway and improve the efficacy of cell therapies are also presented.Finally,we discuss potential future SDDS perspectives in overcoming drug resistance in cancer immunotherapy.We believe that this review will contribute to the rational design of SDDSs and development of novel techniques to overcome immunotherapy resistance.展开更多
Coagulation Factor Xa(FXa)is the crucial enzyme at the convergent point of the intrinsic and extrinsic coagulation pathways.The inhibition of FXa is an effective approach against thrombotic diseases.In the present stu...Coagulation Factor Xa(FXa)is the crucial enzyme at the convergent point of the intrinsic and extrinsic coagulation pathways.The inhibition of FXa is an effective approach against thrombotic diseases.In the present study,a specific strategy is reported to discover 10 novel FXa inhibitors based on ligand-based(pharmacophore)virtual screening and molecular docking analysis from a dataset of specs(containing 220000 molecules).The binding modes analysis provide insights into the contribution of particular structural moieties of the compounds towards their activity against FXa,and 10 novel structural compounds were discovered as potent candidate molecules.This work could be helpful in further design and development of FXa inhibitors.展开更多
Electric vehicle, as a clean energy industry, is an important branch. Electric vehicles not only are the energy of the electric user, but also can be used as mobile and distributed energy storage unit to the grid. As ...Electric vehicle, as a clean energy industry, is an important branch. Electric vehicles not only are the energy of the electric user, but also can be used as mobile and distributed energy storage unit to the grid. As a precondition of safety operation for power grid, studies of EVs’ charging load characteristics is also the theoretical basis of intelligent scheduling EVs charging orderly. This paper assesses the future of the electric vehicles development prospects, and secondly establishes a charging model of a single EV. Then, considering stochastic distribution of the initial state-of-charge (SOC0) and the arriving time of the vehicles, a cluster model of the charging station is proposed. Meanwhile, the paper from the types and charging mode of electric vehicles analyzes the behavior of EV. Finally, an example simulation is validated.展开更多
The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,sp...The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,spatially oriented scaffolds to stimulate osteochondral regeneration,has immense significance.Herein,targeted drugs,namely kartogenin@polydopamine(KGN@PDA)nanoparticles for cartilage repair and miRNA@calcium phosphate(miRNA@CaP)NPs for bone regeneration,were in situ deposited on a patterned supramolecular-assembled 2-ureido-4[lH]-pyrimidinone(UPy)modified gelation hydrogel film,facilitated by the dynamic and responsive coordination and complexation of metal ions and their ligands.This hydrogel film can be rolled into a cylindrical plug,mimicking the Haversian canal structure of natural bone.The resultant hydrogel demonstrates stable mechanical properties,a self-healing ability,a high capability for reactive oxygen species capture,and controlled release of KGN and miR-26a.In vitro,KGN@PDA and miRNA@CaP promote chondrogenic and osteogenic differentiation of mesenchymal stem cells via the JNK/RUNX1 and GSK-3β/β-catenin pathways,respectively.In vivo,the osteochondral plug exhibits optimal subchondral bone and cartilage regeneration,evidenced by a significant increase in glycosaminoglycan and collagen accumulation in specific zones,along with the successful integration of neocartilage with subchondral bone.This biomaterial delivery approach represents a significant toward improved osteochondral repair.展开更多
OBJECTIVE:To investigate effects of Saikosaponin D(SSd) on syndecan-2,matrix metalloproteinases(MMPs) and tissue inhibitor of metalloproteinases-2(TIMP-2) in livers of rat with hepatocellular carcinoma(HCC).METHODS:Ma...OBJECTIVE:To investigate effects of Saikosaponin D(SSd) on syndecan-2,matrix metalloproteinases(MMPs) and tissue inhibitor of metalloproteinases-2(TIMP-2) in livers of rat with hepatocellular carcinoma(HCC).METHODS:Male SD rats were divided into control(n=10),model(n=20) and SSd(n=20) groups,and model and SSd groups given intragastric 0.2%(w/v) N-diethylnitrosamine to induce HCC.SSd group received 0.03%(w/v) SSd in saline.Liver samples were analysed immunohistochemically for syndecan-2,MMP-2,MMP-13 and TIMP-2 at 16 weeks.RESULTS:The model group had more malignant nodules than the SSd group;all model-group HCC cells were grade III;SSd-group HCC cells were grades I-II.Controls showed normal hepatic cell phenotypes and no syndecan-2 + staining.Syndecan-2 + staining was greater in the model group(35.2%,P≤0.001) than in controls or the SSd group(16.5%,P ≤ 0.001).The model group had more intense MMP-2 + staining than controls(0.37 vs 0.27,P≤0.01) or the SSd group(0.31 vs 0.37,P≤0.05);and higher MMP-13 + staining(72.55%) than in controls(12.55%,P≤0.001) and SSd group(20.18%,P≤0.01).The model group also had more TIMP-2 + staining(57.2%) than controls(20.9%,P≤0.001) and SSd group(22.7%,P≤0.001).Controls and SSd group showed no difference in TIMP-2 + rates.CONCLUSION:SSd inhibited HCC development,and downregulated expression of syndecan-2,MMP-2,MMP-13 and TIMP-2 in rat HCC liver tissue.展开更多
Recently,increasing attention has been concentrated on negative permittivity with the development of the emerging metamaterials composed of periodic array structures.However,taking facile preparation into consideratio...Recently,increasing attention has been concentrated on negative permittivity with the development of the emerging metamaterials composed of periodic array structures.However,taking facile preparation into consideration,it is important to achieve negative permittivity behavior based on materials'intrinsic properties rather than their artificially periodic structures.In this paper,we proposed to fabricate the percolating composites with copper dispersed in epoxy(EP)resin by a polymerization method to realize the negative permittivity behavior.When Cu content in the composites reached to 80 wt%,the conductivity abruptly went up by three orders of magnitudes,suggesting a percolation behavior.Below the percolation threshold,the conductivity spectra conform to Jonscher's power law;when the Cu/EP composites reached to percolating state,the conductivity gradually reduced in high frequency region due to the skin effect.It is indicated that the conductive mechanism changed from hopping conduction to electron conduction.In addition,the permittivity did not increase monotonously with the increase of Cu content in the vicinity of percolation threshold,due to the presence of leakage current.Meanwhile,the negative permittivity conforming to Drude model was observed above the percolation threshold.Further investigation revealed that there was a constitutive relationship between the permittivity and the reactance.When conductive fillers are slightly above the percolation threshold,the inductive characteristic derived from conductive percolating network leads to the negative permittivity.Such epsilon-negative materials can potentially be applied in novel electrical devices,such as high-power microwave filters,stacked capacitors,negative capacitance field effect transistors and coil-free resonators.In addition,the design strategy based on percolating composites provides an approach to epsilon-negative materials.展开更多
基金the financial support from National Natural Science Foundation of China(No.51703135)the technical support from Beijing Key Laboratory of Optical Materials and Photonic Devices。
文摘Fluorescence-based imaging applications have been benefiting greatly from donor-acceptor(D-A)/donor-π-acceptor(D-π-A)fluorescent probes owing to their intramolecular charge transfer(ICT)nature and self-assembly behavior.In this study,we design and synthesize a hydrophilic D-A fluorescent probe,namely CHBA,which would self-assemble into interlaced textures down to nanoscale but disassemble by trace amount of water in fingertip area.Upon finger-pressing,it enables fingerprint imaging and covers level-1/2/3 fingerprint information,wherein the sweat pores can be mapped in both bright field model and fluorescence mode,capable of naked-eye-based similarity analysis for personal identity verification(PIV).Spectroscopic analysis and morphology study show that the working mechanism can be attributed to the selective water-erosion effect on the solid-liquid interphase under physical contact.The sweat pore information can be digitized by polar coordinate conversion,further allowing machine-learning-based analysis for PIV application.The final PIV accuracy reaches 100%for all the involved machine-learning models,with no erroneous judgements.A prototype of PIV system is constructed by integrating CHBA with artificial intelligence hardware,wherein the sweat pore imaging,data processing and the decisionmaking could be run in parallel,suggesting high feasibility in real-world application.
基金This work was financially supported by the National Key Research and Development Program of China(2018YFA0702002)the Beijing Natural Science Foundation(Z210016)+1 种基金the National Natural Science Foundation of China(51967020,21935001)Shanxi Energy Internet Research Institute(SXEI 2023A004).
文摘The exploration of sustainable energy utilization requires the imple-mentation of advanced electrochemical devices for efficient energy conversion and storage,which are enabled by the usage of cost-effective,high-performance electro-catalysts.Currently,heterogeneous atomically dispersed catalysts are considered as potential candidates for a wide range of applications.Compared to conventional cata-lysts,atomically dispersed metal atoms in carbon-based catalysts have more unsatu-rated coordination sites,quantum size effect,and strong metal-support interactions,resulting in exceptional catalytic activity.Of these,dual-atomic catalysts(DACs)have attracted extensive attention due to the additional synergistic effect between two adja-cent metal atoms.DACs have the advantages of full active site exposure,high selectiv-ity,theoretical 100%atom utilization,and the ability to break the scaling relationship of adsorption free energy on active sites.In this review,we summarize recent research advancement of DACs,which includes(1)the comprehensive understanding of the synergy between atomic pairs;(2)the synthesis of DACs;(3)characterization meth-ods,especially aberration-corrected scanning transmission electron microscopy and synchrotron spectroscopy;and(4)electrochemical energy-related applications.The last part focuses on great potential for the electrochemical catalysis of energy-related small molecules,such as oxygen reduction reaction,CO_(2) reduction reaction,hydrogen evolution reaction,and N_(2) reduction reaction.The future research challenges and opportunities are also raised in prospective section.
文摘Objective:To explore which pattern recognition receptors(PRRs)play a key role in the development of hand,foot,and mouth disease(HFMD)by analyzing PRR-associated genes.Methods:We conducted a comparative analysis of PRR-associated gene expression in human peripheral blood mononuclear cells(PBMCs)infected with enterovirus 71(EV-A71)which were derived from patients with HFMD of different severities and at different stages.A total of 30 PRR-associated genes were identified as significantly upregulated both over time and across different EV-A71 isolates.Subsequently,ELISA was employed to quantify the expression of the six most prominent genes among these 30 identified genes,specifically,BST2,IRF7,IFI16,TRIM21,MX1,and DDX58.Results:Compared with those at the recovery stage,the expression levels of BST2(P=0.027),IFI16(P=0.016),MX1(P=0.046)and DDX58(P=0.008)in the acute stage of infection were significantly upregulated,while no significant difference in the expression levels of IRF7(P=0.495)and TRIM21(P=0.071)was found between different stages of the disease.The expression levels of BST2,IRF7,IFI16 and MX1 were significantly higher in children infected with single pathogen than those infected with mixed pathogens,and BST2,IRF7,IFI16 and MX1 expression levels were significantly lower in coxsackie B virus(COXB)positive patients than the negative patients.Expression levels of one or more of BST2,IRF7,IFI16,TRIM21,MX1 and DDX58 genes were correlated with PCT levels,various white blood cell counts,and serum antibody levels that reflect disease course of HFMD.Aspartate aminotransferase was correlated with BST2,MX1 and DDX58 expression levels.Conclusions:PRR-associated genes likely initiate the immune response in patients at the acute stage of HFMD.
基金partly supported by the National Natural Science Foundation of China(62273298,62273295)Hebei Natural Science Foundation(F2023203063,F2022203025)+1 种基金China Scholarship Council(CSC)(202308130180)Provincial Key Laboratory Performance Subsidy Project(22567612H)
文摘Dear Editor,Industrial Internet of things(IIoT) is a typical application of cyberphysical system(CPS). In the IIoT, wireless communication is an inevitable trend to replace the deployment-limited wired transmission for cases with large-scale and mobile devices. However, wireless communication gives rise to critical issues related to physical security, such as malicious detections and attacks [1].
基金the financial support provided by the National Natural Science Foundation of China (22008254)the Fundamental Research Funds for the Central Universities (2020XJHH01)+1 种基金the National Training Program of Innovation and Entrepreneurship for Undergraduates (C202003309)China University of Mining and Technology (Beijing) Yueqi Outstanding Scholar Project (2020JCB02)。
文摘Tetrahydrofuran(THF) extract of coal tar pitch(CTP) was used instead of blending CTP with pretreated pyrolysis fuel oil to prepare an isotropic pitch precursor with excellent spinnability for general-purpose carbon fibre through bromination-dehydrobromination. The feasibility and effectiveness of synthesising an isotropic pitch precursor derived from THF-soluble(CTP-THFs) is demonstrated in this study.The results show that CTP-THFs contains more light components than CTP;CTP-THFs and CTP monomer proportions were 62.52% and 45.32%, respectively. However, based on comparisons of CTP-THFsBr0 and CTPBr0 characterisations, CTP-THFs exhibits better polycondensation than CTP. Bromination-dehydrobro mination promotes polycondensation of pitch precursors, leading to greater carbon aromaticity in CTP-THFsBr5, CTP-THFsBr10, and CTP-THFsBr15 than that in CTP-THFsBr0 and CTPBr0. CTP-THFsBr5 and CTP-THFsBr10 have excellent spinnability even with softening points as high as 230 ℃. The pericondensed carbon and carbon aromaticity of CTP-THFsBr5 and CTP-THFsBr10 are high owing to the higher degree of polycondensation;however, they still possess a more linear molecular structure. The as-prepared carbon fibre exhibits homogeneity and uniformity, and the mechanical performance is comparable with that of commercial general-purpose carbon fibre products.
基金supported by the National Key R&D Program of China(Grant No.2022YFC3401404)the National Natural Science Foundation of China(Grant Nos.32170935 and 31930066).
文摘Cancer immunotherapy,a therapeutic approach that inhibits tumors by activating or strengthening anti-tumor immunity,is currently an important clinical strategy for cancer treatment;however,tumors can develop drug resistance to immune surveillance,resulting in poor response rates and low therapeutic efficacy.In addition,changes in genes and signaling pathways in tumor cells prevent susceptibility to immunotherapeutic agents.Furthermore,tumors create an immunosuppressive microenvironment via immunosuppressive cells and secrete molecules that hinder immune cell and immune modulator infiltration or induce immune cell malfunction.To address these challenges,smart drug delivery systems(SDDSs)have been developed to overcome tumor cell resistance to immunomodulators,restore or boost immune cell activity,and magnify immune responses.To combat resistance to small molecules and monoclonal antibodies,SDDSs are used to co-deliver numerous therapeutic agents to tumor cells or immunosuppressive cells,thus increasing the drug concentration at the target site and improving efficacy.Herein,we discuss how SDDSs overcome drug resistance during cancer immunotherapy,with a focus on recent SDDS advances in thwarting drug resistance in immunotherapy by combining immunogenic cell death with immunotherapy and reversing the tumor immunosuppressive microenvironment.SDDSs that modulate the interferon signaling pathway and improve the efficacy of cell therapies are also presented.Finally,we discuss potential future SDDS perspectives in overcoming drug resistance in cancer immunotherapy.We believe that this review will contribute to the rational design of SDDSs and development of novel techniques to overcome immunotherapy resistance.
基金the Science and Technology Innovation Talent Project of Sichuanprovince (Grant number 2016073).
文摘Coagulation Factor Xa(FXa)is the crucial enzyme at the convergent point of the intrinsic and extrinsic coagulation pathways.The inhibition of FXa is an effective approach against thrombotic diseases.In the present study,a specific strategy is reported to discover 10 novel FXa inhibitors based on ligand-based(pharmacophore)virtual screening and molecular docking analysis from a dataset of specs(containing 220000 molecules).The binding modes analysis provide insights into the contribution of particular structural moieties of the compounds towards their activity against FXa,and 10 novel structural compounds were discovered as potent candidate molecules.This work could be helpful in further design and development of FXa inhibitors.
文摘Electric vehicle, as a clean energy industry, is an important branch. Electric vehicles not only are the energy of the electric user, but also can be used as mobile and distributed energy storage unit to the grid. As a precondition of safety operation for power grid, studies of EVs’ charging load characteristics is also the theoretical basis of intelligent scheduling EVs charging orderly. This paper assesses the future of the electric vehicles development prospects, and secondly establishes a charging model of a single EV. Then, considering stochastic distribution of the initial state-of-charge (SOC0) and the arriving time of the vehicles, a cluster model of the charging station is proposed. Meanwhile, the paper from the types and charging mode of electric vehicles analyzes the behavior of EV. Finally, an example simulation is validated.
基金the Natural Science Foundation of China(Grant Nos.82072413,82101649)National Key Research and Development Program of China(Grant Nos.2021YFE0105400).
文摘The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,spatially oriented scaffolds to stimulate osteochondral regeneration,has immense significance.Herein,targeted drugs,namely kartogenin@polydopamine(KGN@PDA)nanoparticles for cartilage repair and miRNA@calcium phosphate(miRNA@CaP)NPs for bone regeneration,were in situ deposited on a patterned supramolecular-assembled 2-ureido-4[lH]-pyrimidinone(UPy)modified gelation hydrogel film,facilitated by the dynamic and responsive coordination and complexation of metal ions and their ligands.This hydrogel film can be rolled into a cylindrical plug,mimicking the Haversian canal structure of natural bone.The resultant hydrogel demonstrates stable mechanical properties,a self-healing ability,a high capability for reactive oxygen species capture,and controlled release of KGN and miR-26a.In vitro,KGN@PDA and miRNA@CaP promote chondrogenic and osteogenic differentiation of mesenchymal stem cells via the JNK/RUNX1 and GSK-3β/β-catenin pathways,respectively.In vivo,the osteochondral plug exhibits optimal subchondral bone and cartilage regeneration,evidenced by a significant increase in glycosaminoglycan and collagen accumulation in specific zones,along with the successful integration of neocartilage with subchondral bone.This biomaterial delivery approach represents a significant toward improved osteochondral repair.
基金Supported by the National Natural Science Foundation of China(No.30471982)
文摘OBJECTIVE:To investigate effects of Saikosaponin D(SSd) on syndecan-2,matrix metalloproteinases(MMPs) and tissue inhibitor of metalloproteinases-2(TIMP-2) in livers of rat with hepatocellular carcinoma(HCC).METHODS:Male SD rats were divided into control(n=10),model(n=20) and SSd(n=20) groups,and model and SSd groups given intragastric 0.2%(w/v) N-diethylnitrosamine to induce HCC.SSd group received 0.03%(w/v) SSd in saline.Liver samples were analysed immunohistochemically for syndecan-2,MMP-2,MMP-13 and TIMP-2 at 16 weeks.RESULTS:The model group had more malignant nodules than the SSd group;all model-group HCC cells were grade III;SSd-group HCC cells were grades I-II.Controls showed normal hepatic cell phenotypes and no syndecan-2 + staining.Syndecan-2 + staining was greater in the model group(35.2%,P≤0.001) than in controls or the SSd group(16.5%,P ≤ 0.001).The model group had more intense MMP-2 + staining than controls(0.37 vs 0.27,P≤0.01) or the SSd group(0.31 vs 0.37,P≤0.05);and higher MMP-13 + staining(72.55%) than in controls(12.55%,P≤0.001) and SSd group(20.18%,P≤0.01).The model group also had more TIMP-2 + staining(57.2%) than controls(20.9%,P≤0.001) and SSd group(22.7%,P≤0.001).Controls and SSd group showed no difference in TIMP-2 + rates.CONCLUSION:SSd inhibited HCC development,and downregulated expression of syndecan-2,MMP-2,MMP-13 and TIMP-2 in rat HCC liver tissue.
基金sponsored by the National Natural Science Foundation of China (Grant No.51803119,51871146 and 51771108)the Innovation Program of Shanghai Municipal Education Commission (Grant No.2019-01-07-00-10-E00053)+1 种基金"Chenguang Program" supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission (Grant No.18CG56)the Science and Technology Commission of Shanghai Municipality (Grant No.18DZ1112902,No.18DZ1100802)
文摘Recently,increasing attention has been concentrated on negative permittivity with the development of the emerging metamaterials composed of periodic array structures.However,taking facile preparation into consideration,it is important to achieve negative permittivity behavior based on materials'intrinsic properties rather than their artificially periodic structures.In this paper,we proposed to fabricate the percolating composites with copper dispersed in epoxy(EP)resin by a polymerization method to realize the negative permittivity behavior.When Cu content in the composites reached to 80 wt%,the conductivity abruptly went up by three orders of magnitudes,suggesting a percolation behavior.Below the percolation threshold,the conductivity spectra conform to Jonscher's power law;when the Cu/EP composites reached to percolating state,the conductivity gradually reduced in high frequency region due to the skin effect.It is indicated that the conductive mechanism changed from hopping conduction to electron conduction.In addition,the permittivity did not increase monotonously with the increase of Cu content in the vicinity of percolation threshold,due to the presence of leakage current.Meanwhile,the negative permittivity conforming to Drude model was observed above the percolation threshold.Further investigation revealed that there was a constitutive relationship between the permittivity and the reactance.When conductive fillers are slightly above the percolation threshold,the inductive characteristic derived from conductive percolating network leads to the negative permittivity.Such epsilon-negative materials can potentially be applied in novel electrical devices,such as high-power microwave filters,stacked capacitors,negative capacitance field effect transistors and coil-free resonators.In addition,the design strategy based on percolating composites provides an approach to epsilon-negative materials.
