In the past twenty years, electromagnetic metamaterials represented by left-handed metamaterials（LHMs） have attracted considerable attention due to the unique properties such as negative refraction, perfect lens, an...In the past twenty years, electromagnetic metamaterials represented by left-handed metamaterials（LHMs） have attracted considerable attention due to the unique properties such as negative refraction, perfect lens, and electromagnetic cloaks. In this paper, we present a comprehensive review of our group＇s work on metamaterials and metasurfaces. We present several types of LHMs and chiral metamaterials. As a two-dimensional equivalent of bulk three-dimensional metamaterials, metasurfaces have led to a myriad of devices due to the advantages of lower profile, lower losses, and simpler to fabricate than bulk three-dimensional metamaterials. We demonstrate the novel microwave metadevices based on metamaterials and metasurfaces： perfect absorbers and microwave patch antennas, including novel transmission line antennas,high gain resonant cavity antennas, wide scanning phased array antennas, and circularly polarized antennas.展开更多
In this paper,we consider the global well-posedness of smooth solutions for the Cauchy problem of a sixth order convective Cahn-Hilliard equation with small initial data.We first construct a local smooth solution,then...In this paper,we consider the global well-posedness of smooth solutions for the Cauchy problem of a sixth order convective Cahn-Hilliard equation with small initial data.We first construct a local smooth solution,then by combining some a priori estimates,continuity argument,the local smooth solution is extended step by step to all t>0 provided that the L1 norm of initial data is suitably small and the smooth nonlinear functions f(u)and g(u)satisfy certain local growth conditions at some fixed point■.展开更多
Objective:To investigate clinical application of aconite root(Aconitum carmichaelii Debx.;hereinafter“aconite”)by traditional Chinese medicine(TCM)physicians in TCM hospitals in Beijing and explore the specific use ...Objective:To investigate clinical application of aconite root(Aconitum carmichaelii Debx.;hereinafter“aconite”)by traditional Chinese medicine(TCM)physicians in TCM hospitals in Beijing and explore the specific use of aconite and the effect of different doses on decoction time.Methods:This was a cross-sectional study using two-stage sampling.Questionnaires were administered among TCM physicians from TCM hospitals in Beijing between September 2020 and August 2021.The questionnaire mainly included general demographics,clinical backgrounds of TCM physicians,and clinical application of aconite.The data analyses were performed using SPSS 20.0.Results:A total of 387 questionnaires were collected,of which 385 were valid.Of the 385 participating TCM physicians,331(85.97%)used aconite in clinical practice.The top three medical diagnoses treated with aconite were heart failure,diarrhea without cause,and chronic gastritis.The TCM pattern treated most frequently with a high dose of aconite was spleen-kidney yang deficiency,and the TCM pattern treated most frequently with a low dose was spleen yang deficiency,while spleen-kidney yang deficiency was treated most frequently with a common dose of aconite.The top three common formulas were Sini decoction,Mahuang Xixin Fuzi decoction,and Zhenwu decoction.Hei Shun Pian was the most common herbal pieces of aconite.The highest frequency of the maximum dose of aconite was 15 g,that of the minimum dose was 3 g,and that of the common dose was 10 g.There was a certain correlation between decoction time and the dose of aconite.Most TCM physicians advised their patients to take medicine twice a day.Conclusion:In this study,we refined and quantified the use of aconite and enriched the exploration of the clinical application of aconite besides its provisions in the Pharmacopoeia of the People's Republic of China.展开更多
Objective:To understand the attitudes and perceptions of traditional Chinese medicine(TCM)practitioners in Beijing TCM hospitals regarding the use of Ephedra sinica Stapf(E.sinica,Ma Huang).Methods:A two-stage cross-s...Objective:To understand the attitudes and perceptions of traditional Chinese medicine(TCM)practitioners in Beijing TCM hospitals regarding the use of Ephedra sinica Stapf(E.sinica,Ma Huang).Methods:A two-stage cross-sectional study was conducted using a questionnaire survey of TCM practi-tioners in Beijing TCM hospitals between April 2023 and March 2024.The questionnaire included de-mographic information,the clinical background of TCM practitioners,and the clinical application of E.sinica.Logistic regression analysis was used to analyze the relevant influencing factors when using E.sinica.Results:Of the 465 questionnaires collected,441 were valid.Among these,84.81%(374/441)reported having used E.sinica in clinical practice at least once.The commonly used doses of E.sinicadexcluding the pediatric departmentdwere 10 g for high doses,6 g for medium,and 3 g for low.The three most frequently used formulas for E.sinica included Maxing Shigan decoction,Mahuang decoction,and Xiao Qing Long decoction.The most common TCM patterns treated with a high dose of E.sinica were wind-cold exterior pattern,wind-cold invading the lung,and wind and water combat with meridians con-gealed by cold.The top three Western medical diagnoses when using E.sinica for treatment were common cold,pneumonia,and upper respiratory tract infections.Nearly half of the respondents reported experiencing adverse reactions from the oral administration of E.sinica,with the most common being palpitations,insomnia,and restlessness.Starting with a low dose and gradually increasing it as appro-priate was identified as an effective approach.Conclusion:This study investigated the attitudes and perceptions of TCM practitioners in Beijing TCM hospitals regarding the doseeefficacyeadverse reaction relationship of E.sinica,providing a reference for the safe and effective clinical use of E.sinica.展开更多
Recent developments in cutting-edge live microscopy and image analysis provide a unique opportunity to systematically investigate individual cell’s dynamics as well as simulation-based hypothesis testing. After a sum...Recent developments in cutting-edge live microscopy and image analysis provide a unique opportunity to systematically investigate individual cell’s dynamics as well as simulation-based hypothesis testing. After a summary of data generation and analysis in the observation and modeling efforts related to C. elegans embryogenesis, we develop a systematic approach to model the basic behaviors of individual cells. Next, we present our ideas to model cell fate, division, and movement using 3D time-lapse images within an agent-based modeling framework. Then, we summarize preliminary result and discuss efforts in cell fate, division, and movement modeling. Finally, we discuss the ongoing efforts and future directions for C. elegans embryo modeling, including an inferred developmental landscape for cell fate, a quasi-equilibrium model for cell division, and multi-agent, deep reinforcement learning for cell movement.展开更多
Symmetry plays a fundamental role in topological photonic crystals, and topological phase transitions induced bydisorder have also been extensively explored in recent years. However, in this work, we find anisotropy c...Symmetry plays a fundamental role in topological photonic crystals, and topological phase transitions induced bydisorder have also been extensively explored in recent years. However, in this work, we find anisotropy can beinduced by reducing symmetry in a C_(2v) symmetry triangular photonic crystal. We investigate that anisotropyinducedinterfaces profoundly affect edge states and enable the realization of slow light dispersion. Numericalsimulations reveal a transition from gapless chiral edge modes to gapped flat band dispersion. Furthermore, weobserve higher-order corner states in corner structures constructed by anisotropic interfaces. The corner states canbe induced and localized at different lattice positions, thereby realizing multiple types of higher-order topologicalstates. We demonstrate the significance of anisotropic geometry in topological photonics. These findings opennew possibilities for steering wave transport in multiple dimensions and offer, to our knowledge, a novel researchperspective on the transformation of topological states induced by anisotropic lattices.展开更多
The high cadmium(Cd)accumulation ability of wheat has garnered significant attention in China.It is crucial to identify the key factors affecting Cd accumulation in wheat and to develop predictive models to derive the...The high cadmium(Cd)accumulation ability of wheat has garnered significant attention in China.It is crucial to identify the key factors affecting Cd accumulation in wheat and to develop predictive models to derive the threshold concentration of Cd in soil for safe wheat production.A total of 311 soil–wheat paired datasets were collected from both literature and field surveys in China,in which the ranges of Cd in soil and wheat grain were 0.068–13.500 mg/kg and 0.006–2.190 mg/kg,respectively.Correlation analyses and Partial Least Squares Path Model indicated that soil Cd,soil pH,and CEC together controlled the transfer of Cd from soil to wheat.Multiple linear regression models were successfully established using soil Cd contents or bioavailable Cd(extracted by CaCl2 or calculated using a multi-surface speciation model),pH,and CEC as input variables to predict wheat Cd(RMSE¼0.242–0.327,MAE¼0.188–0.249).Furthermore,the Extreme Random Tree model(RMSE¼0.221,MAE¼0.165)outperformed the other seven machine learning algorithms.The thresholds for both soil total Cd and bioavailable Cd for safe wheat production were further back-calculated according to the permissible value of Cd in wheat grain,which demonstrated enhanced protection accuracy compared to the current soil quality standard.Our findings facilitate a quantitative assessment of Cd accumulation risk in wheat,offering a valuable reference for the safe production of wheat.展开更多
Optical metamaterials offer the possibility of controlling the behavior of photons similarly to what has been done about electrons in semiconductors.However,most optical metamaterials are narrowband,and they achieve n...Optical metamaterials offer the possibility of controlling the behavior of photons similarly to what has been done about electrons in semiconductors.However,most optical metamaterials are narrowband,and they achieve negative refraction within a small window of incident angles,making them impractical for common visible light systems that operate effectively over a wide range of frequencies and directions.Considerable resistive loss at the resonant frequency of these metamaterials further prevents them from being deployed in the real world.Here,we develop a novel metamaterial randomly assembled by a list of narrowband,omnidirectional,and ultralow-loss meta-cluster systems using a bottom-up approach.Weak interactions among numerous meta-cluster sets greatly broaden the effective bandwidth of the overall structure,exhibiting frequency selectivity and spatial modulation when responding to white-light illumination.We observe negative refraction in the 490–730 nm band,and observe an inverse Doppler effect at green,yellow,and red frequencies,across most of the visible spectrum.Our method allows for low-cost fabrication of sizable broadband omnidirectional three-dimensional metamaterial samples,which opens the door to the rapid development of optical metamaterials,micro–nano assembly and preparation,tunable optical device engineering,etc.展开更多
Optical metamaterials present opportunities and challenges for manipulation of light. However, metamaterials with visible and near infrared responses are still particularly challenging to fabricate due to the complex ...Optical metamaterials present opportunities and challenges for manipulation of light. However, metamaterials with visible and near infrared responses are still particularly challenging to fabricate due to the complex preparation process and high loss. Here, a visible light poly(amidoamine)(PAMAM)-Ag metamaterial is prepared with the assistance of fifth-generation PAMAM(5G PAMAM), based on the dendritic structure. The large area of metamaterials, where Ag nanoparticles are spherical with diameters of ~9 nm and distributed in a multilevel netlike sphere, results in broadband resonance. The negative Goos–Hanchen shift and anomalous spin Hall effect of light generated by 5G PAMAM-Ag in visible broadband are observed, and a strong slab focusing effect at 750–1050 nm is demonstrated. In addition, the simulation shows possible application of the dendritic structure in topological photonics. The results offer advances in the preparation of large-scale visible light metamaterials, showing the potential for subwavelength super-resolution imaging and quantum optical information fields.展开更多
Amphiphilic copolymers can self-assemble into nano-objects in aqueous solution.However,the selfassembly process is usually performed in a diluted solution(<1 wt%),which greatly limits scale-up production and furthe...Amphiphilic copolymers can self-assemble into nano-objects in aqueous solution.However,the selfassembly process is usually performed in a diluted solution(<1 wt%),which greatly limits scale-up production and further biomedical applications.With recent development of controlled polymerization techniques,polymerization-induced self-assembly(PISA)has emerged as an efficient approach for facile fabrication of nano-sized structures with a high concentration as high as 50 wt%.In this review,after the introduction,various polymerization method-mediated PISAs that include nitroxide-mediated polymerization-mediated PISA(NMP-PISA),reversible addition-fragmentation chain transfer polymerizationmediated PISA(RAFT-PISA),atom transfer radical polymerization-mediated PISA(ATRP-PISA),and ringopening polymerization-mediated PISA(ROP-PISA)are discussed carefully.Afterward,recent biomedical applications of PISA are illustrated from the following aspects,i.e.,bioimaging,disease treatment,biocatalysis,and antimicrobial.In the end,current achievements and future perspectives of PISA are given.It is envisioned that PISA strategy can bring great chance for future design and construction of functional nano-vehicles.展开更多
Incorporation of fog computing with low latency,preprocession(e.g.,data aggregation)and location awareness,can facilitate fine-grained collection of smart metering data in smart grid and promotes the sustainability an...Incorporation of fog computing with low latency,preprocession(e.g.,data aggregation)and location awareness,can facilitate fine-grained collection of smart metering data in smart grid and promotes the sustainability and efficiency of the grid.Recently,much attention has been paid to the research on smart grid,especially in protecting privacy and data aggregation.However,most previous works do not focus on privacy-preserving data aggregation and function computation query on enormous data simultaneously in smart grid based on fog computation.In this paper,we construct a novel verifiable privacy-preserving data collection scheme supporting multi-party computation(MPC),named VPDC-MPC,to achieve both functions simultaneously in smart grid based on fog computing.VPDC-MPC realizes verifiable secret sharing of users’data and data aggregation without revealing individual reports via practical cryptosystem and verifiable secret sharing scheme.Besides,we propose an efficient algorithm for batch verification of share consistency and detection of error reports if the external adversaries modify the SMs’report.Furthermore,VPDC-MPC allows both the control center and users with limited resources to obtain arbitrary arithmetic analysis(not only data aggregation)via secure multi-party computation between cloud servers in smart grid.Besides,VPDC-MPC tolerates fault of cloud servers and resists collusion.We also present security analysis and performance evaluation of our scheme,which indicates that even with tradeoff on computation and communication overhead,VPDC-MPC is practical with above features.展开更多
Polymer-induced self-assembly of inorganic nanoparticles has emerged as a powerful strategy for fabrication of stimuliresponsive drug delivery nanosystems.Herein,we designed and synthesized a series of lipoic acid-cap...Polymer-induced self-assembly of inorganic nanoparticles has emerged as a powerful strategy for fabrication of stimuliresponsive drug delivery nanosystems.Herein,we designed and synthesized a series of lipoic acid-capped polysarcosine-bpolycaprolactone(PSar-b-PCL)block copolymers.The self-assembly of gold nanoparticles drove by these block copolymers was systematically investigated,and the preparation of near-infrared(NIR)light-responsive PSar-decorated gold nanovesicle(PSGV)was optimized.DOX as anticancer drug was efficiently encapsulated within the cavity of PSGV.The PSGV greatly prevented doxorubicin(DOX)from premature leakage.While upon 808 nm laser irradiation,most of loaded DOX was rapidly released,along with the recovery of DOX fluorescence.Impressively,the DOX-loaded PSGV(DOX-PSGV)exhibited much higher cell uptake efficiency when compared to DOX-loaded polyethylene glycol(PEG)-coated gold nanovesicle(DOX-PEGV).Thanks to the synergistic photothermal/chemo therapy,the DOX-PSGV had highly superior antitumor efficacy in established 4T1 tumor model.展开更多
The one-pot combination of biocatalytic and chemocatalytic reactions represents an economically and ecologically attractive concept in the emerging cascade processes for manufacturing.The mutual incompatibility of bio...The one-pot combination of biocatalytic and chemocatalytic reactions represents an economically and ecologically attractive concept in the emerging cascade processes for manufacturing.The mutual incompatibility of biocatalysis and chemocatalysis,however,usually causes the deactivation of catalysts,the mismatching of reaction dynamic,and further challenges their integration into concurrent chemo-biocascades.Herein,we have developed a convenient strategy to construct versatile functional metal-organic framework micro-nanoreactors(MOF-MNRs),which can realize not only the encapsulation and protection of biocatalysts but also the controllable transmission of substances and the mutual communication of the incompatible chemo-biosystems.Importantly,the MOFs serving as the shell of MNRs have the capability of enriching the chemocatalysts on the surface and improving the activity of the chemocatalysts to sufficiently match the optimum aqueous reaction system of biocatalysts,which greatly increase the efficiency in the combined concurrent chemo-biocatalysis.Such strategy of constructing MOF-MNRs provides a unique platform for connecting the“two worlds”of chemocatalysis and biocatalysis.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674267,51272215,11874301,and 11204241)the National Basic Research Program of China(Grant No.2012CB921503)+2 种基金the National Aerospace Science Foundation of China(Grant No.2016ZF53061)the Fundamental Research Funds for the Central Universities,China(Grant No.3102017jghk02004)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2017JM1009)
文摘In the past twenty years, electromagnetic metamaterials represented by left-handed metamaterials（LHMs） have attracted considerable attention due to the unique properties such as negative refraction, perfect lens, and electromagnetic cloaks. In this paper, we present a comprehensive review of our group＇s work on metamaterials and metasurfaces. We present several types of LHMs and chiral metamaterials. As a two-dimensional equivalent of bulk three-dimensional metamaterials, metasurfaces have led to a myriad of devices due to the advantages of lower profile, lower losses, and simpler to fabricate than bulk three-dimensional metamaterials. We demonstrate the novel microwave metadevices based on metamaterials and metasurfaces： perfect absorbers and microwave patch antennas, including novel transmission line antennas,high gain resonant cavity antennas, wide scanning phased array antennas, and circularly polarized antennas.
基金Supported by the Fundamental Research Funds for the Central Universities(Grant No.N2005031)。
文摘In this paper,we consider the global well-posedness of smooth solutions for the Cauchy problem of a sixth order convective Cahn-Hilliard equation with small initial data.We first construct a local smooth solution,then by combining some a priori estimates,continuity argument,the local smooth solution is extended step by step to all t>0 provided that the L1 norm of initial data is suitably small and the smooth nonlinear functions f(u)and g(u)satisfy certain local growth conditions at some fixed point■.
基金supported by the project of the Beijing University of Chinese Medicine(2019-HXFZJJ-037).
文摘Objective:To investigate clinical application of aconite root(Aconitum carmichaelii Debx.;hereinafter“aconite”)by traditional Chinese medicine(TCM)physicians in TCM hospitals in Beijing and explore the specific use of aconite and the effect of different doses on decoction time.Methods:This was a cross-sectional study using two-stage sampling.Questionnaires were administered among TCM physicians from TCM hospitals in Beijing between September 2020 and August 2021.The questionnaire mainly included general demographics,clinical backgrounds of TCM physicians,and clinical application of aconite.The data analyses were performed using SPSS 20.0.Results:A total of 387 questionnaires were collected,of which 385 were valid.Of the 385 participating TCM physicians,331(85.97%)used aconite in clinical practice.The top three medical diagnoses treated with aconite were heart failure,diarrhea without cause,and chronic gastritis.The TCM pattern treated most frequently with a high dose of aconite was spleen-kidney yang deficiency,and the TCM pattern treated most frequently with a low dose was spleen yang deficiency,while spleen-kidney yang deficiency was treated most frequently with a common dose of aconite.The top three common formulas were Sini decoction,Mahuang Xixin Fuzi decoction,and Zhenwu decoction.Hei Shun Pian was the most common herbal pieces of aconite.The highest frequency of the maximum dose of aconite was 15 g,that of the minimum dose was 3 g,and that of the common dose was 10 g.There was a certain correlation between decoction time and the dose of aconite.Most TCM physicians advised their patients to take medicine twice a day.Conclusion:In this study,we refined and quantified the use of aconite and enriched the exploration of the clinical application of aconite besides its provisions in the Pharmacopoeia of the People's Republic of China.
基金supported by the Scientific Project of the China Medical Association of Minorities(2023ZY-182-07)and the horizontal project of Beijing University of Chinese Medicine.
文摘Objective:To understand the attitudes and perceptions of traditional Chinese medicine(TCM)practitioners in Beijing TCM hospitals regarding the use of Ephedra sinica Stapf(E.sinica,Ma Huang).Methods:A two-stage cross-sectional study was conducted using a questionnaire survey of TCM practi-tioners in Beijing TCM hospitals between April 2023 and March 2024.The questionnaire included de-mographic information,the clinical background of TCM practitioners,and the clinical application of E.sinica.Logistic regression analysis was used to analyze the relevant influencing factors when using E.sinica.Results:Of the 465 questionnaires collected,441 were valid.Among these,84.81%(374/441)reported having used E.sinica in clinical practice at least once.The commonly used doses of E.sinicadexcluding the pediatric departmentdwere 10 g for high doses,6 g for medium,and 3 g for low.The three most frequently used formulas for E.sinica included Maxing Shigan decoction,Mahuang decoction,and Xiao Qing Long decoction.The most common TCM patterns treated with a high dose of E.sinica were wind-cold exterior pattern,wind-cold invading the lung,and wind and water combat with meridians con-gealed by cold.The top three Western medical diagnoses when using E.sinica for treatment were common cold,pneumonia,and upper respiratory tract infections.Nearly half of the respondents reported experiencing adverse reactions from the oral administration of E.sinica,with the most common being palpitations,insomnia,and restlessness.Starting with a low dose and gradually increasing it as appro-priate was identified as an effective approach.Conclusion:This study investigated the attitudes and perceptions of TCM practitioners in Beijing TCM hospitals regarding the doseeefficacyeadverse reaction relationship of E.sinica,providing a reference for the safe and effective clinical use of E.sinica.
文摘Recent developments in cutting-edge live microscopy and image analysis provide a unique opportunity to systematically investigate individual cell’s dynamics as well as simulation-based hypothesis testing. After a summary of data generation and analysis in the observation and modeling efforts related to C. elegans embryogenesis, we develop a systematic approach to model the basic behaviors of individual cells. Next, we present our ideas to model cell fate, division, and movement using 3D time-lapse images within an agent-based modeling framework. Then, we summarize preliminary result and discuss efforts in cell fate, division, and movement modeling. Finally, we discuss the ongoing efforts and future directions for C. elegans embryo modeling, including an inferred developmental landscape for cell fate, a quasi-equilibrium model for cell division, and multi-agent, deep reinforcement learning for cell movement.
基金National Natural Science Foundation of China(12374296,62401474)Key Research and Development Program of Shaanxi Province(2023-YBGY-247,2024GXZDCYL-01-31)+1 种基金Basic and Applied Basic Research Foundation of Guangdong Province(2024A1515011725)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX2024029)。
文摘Symmetry plays a fundamental role in topological photonic crystals, and topological phase transitions induced bydisorder have also been extensively explored in recent years. However, in this work, we find anisotropy can beinduced by reducing symmetry in a C_(2v) symmetry triangular photonic crystal. We investigate that anisotropyinducedinterfaces profoundly affect edge states and enable the realization of slow light dispersion. Numericalsimulations reveal a transition from gapless chiral edge modes to gapped flat band dispersion. Furthermore, weobserve higher-order corner states in corner structures constructed by anisotropic interfaces. The corner states canbe induced and localized at different lattice positions, thereby realizing multiple types of higher-order topologicalstates. We demonstrate the significance of anisotropic geometry in topological photonics. These findings opennew possibilities for steering wave transport in multiple dimensions and offer, to our knowledge, a novel researchperspective on the transformation of topological states induced by anisotropic lattices.
基金financially supported by the Natural Science Foundation of China(42177188,21876080).
文摘The high cadmium(Cd)accumulation ability of wheat has garnered significant attention in China.It is crucial to identify the key factors affecting Cd accumulation in wheat and to develop predictive models to derive the threshold concentration of Cd in soil for safe wheat production.A total of 311 soil–wheat paired datasets were collected from both literature and field surveys in China,in which the ranges of Cd in soil and wheat grain were 0.068–13.500 mg/kg and 0.006–2.190 mg/kg,respectively.Correlation analyses and Partial Least Squares Path Model indicated that soil Cd,soil pH,and CEC together controlled the transfer of Cd from soil to wheat.Multiple linear regression models were successfully established using soil Cd contents or bioavailable Cd(extracted by CaCl2 or calculated using a multi-surface speciation model),pH,and CEC as input variables to predict wheat Cd(RMSE¼0.242–0.327,MAE¼0.188–0.249).Furthermore,the Extreme Random Tree model(RMSE¼0.221,MAE¼0.165)outperformed the other seven machine learning algorithms.The thresholds for both soil total Cd and bioavailable Cd for safe wheat production were further back-calculated according to the permissible value of Cd in wheat grain,which demonstrated enhanced protection accuracy compared to the current soil quality standard.Our findings facilitate a quantitative assessment of Cd accumulation risk in wheat,offering a valuable reference for the safe production of wheat.
基金National Natural Science Foundation of China (52272306,11674267).
文摘Optical metamaterials offer the possibility of controlling the behavior of photons similarly to what has been done about electrons in semiconductors.However,most optical metamaterials are narrowband,and they achieve negative refraction within a small window of incident angles,making them impractical for common visible light systems that operate effectively over a wide range of frequencies and directions.Considerable resistive loss at the resonant frequency of these metamaterials further prevents them from being deployed in the real world.Here,we develop a novel metamaterial randomly assembled by a list of narrowband,omnidirectional,and ultralow-loss meta-cluster systems using a bottom-up approach.Weak interactions among numerous meta-cluster sets greatly broaden the effective bandwidth of the overall structure,exhibiting frequency selectivity and spatial modulation when responding to white-light illumination.We observe negative refraction in the 490–730 nm band,and observe an inverse Doppler effect at green,yellow,and red frequencies,across most of the visible spectrum.Our method allows for low-cost fabrication of sizable broadband omnidirectional three-dimensional metamaterial samples,which opens the door to the rapid development of optical metamaterials,micro–nano assembly and preparation,tunable optical device engineering,etc.
基金National Natural Science Foundation of China(11674267,51272215).
文摘Optical metamaterials present opportunities and challenges for manipulation of light. However, metamaterials with visible and near infrared responses are still particularly challenging to fabricate due to the complex preparation process and high loss. Here, a visible light poly(amidoamine)(PAMAM)-Ag metamaterial is prepared with the assistance of fifth-generation PAMAM(5G PAMAM), based on the dendritic structure. The large area of metamaterials, where Ag nanoparticles are spherical with diameters of ~9 nm and distributed in a multilevel netlike sphere, results in broadband resonance. The negative Goos–Hanchen shift and anomalous spin Hall effect of light generated by 5G PAMAM-Ag in visible broadband are observed, and a strong slab focusing effect at 750–1050 nm is demonstrated. In addition, the simulation shows possible application of the dendritic structure in topological photonics. The results offer advances in the preparation of large-scale visible light metamaterials, showing the potential for subwavelength super-resolution imaging and quantum optical information fields.
基金This work was financially supported from the Natural Science Foundation of Jiangsu Province(no.BK20200709)the Natural Science Foundation of China(no.62288102)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutes(no.20KJB430031)the startup fund from Nanjing Tech University.
文摘Amphiphilic copolymers can self-assemble into nano-objects in aqueous solution.However,the selfassembly process is usually performed in a diluted solution(<1 wt%),which greatly limits scale-up production and further biomedical applications.With recent development of controlled polymerization techniques,polymerization-induced self-assembly(PISA)has emerged as an efficient approach for facile fabrication of nano-sized structures with a high concentration as high as 50 wt%.In this review,after the introduction,various polymerization method-mediated PISAs that include nitroxide-mediated polymerization-mediated PISA(NMP-PISA),reversible addition-fragmentation chain transfer polymerizationmediated PISA(RAFT-PISA),atom transfer radical polymerization-mediated PISA(ATRP-PISA),and ringopening polymerization-mediated PISA(ROP-PISA)are discussed carefully.Afterward,recent biomedical applications of PISA are illustrated from the following aspects,i.e.,bioimaging,disease treatment,biocatalysis,and antimicrobial.In the end,current achievements and future perspectives of PISA are given.It is envisioned that PISA strategy can bring great chance for future design and construction of functional nano-vehicles.
基金This work was supported in part by the National Key Research and Development Project of China(Grant No.2020YFA0712300)in part by the National Natural Science Foundation of China(Grant Nos.62132005,61632012,62172162 and 62072404).
文摘Incorporation of fog computing with low latency,preprocession(e.g.,data aggregation)and location awareness,can facilitate fine-grained collection of smart metering data in smart grid and promotes the sustainability and efficiency of the grid.Recently,much attention has been paid to the research on smart grid,especially in protecting privacy and data aggregation.However,most previous works do not focus on privacy-preserving data aggregation and function computation query on enormous data simultaneously in smart grid based on fog computation.In this paper,we construct a novel verifiable privacy-preserving data collection scheme supporting multi-party computation(MPC),named VPDC-MPC,to achieve both functions simultaneously in smart grid based on fog computing.VPDC-MPC realizes verifiable secret sharing of users’data and data aggregation without revealing individual reports via practical cryptosystem and verifiable secret sharing scheme.Besides,we propose an efficient algorithm for batch verification of share consistency and detection of error reports if the external adversaries modify the SMs’report.Furthermore,VPDC-MPC allows both the control center and users with limited resources to obtain arbitrary arithmetic analysis(not only data aggregation)via secure multi-party computation between cloud servers in smart grid.Besides,VPDC-MPC tolerates fault of cloud servers and resists collusion.We also present security analysis and performance evaluation of our scheme,which indicates that even with tradeoff on computation and communication overhead,VPDC-MPC is practical with above features.
基金supported by the financial support from the Natural Science Foundation of Jiangsu Province(No.BK20200709)the Natural Science Foundation of the Jiangsu Higher Education Institutes(No.20KJB430031)the startup fund from Nanjing Tech University.
文摘Polymer-induced self-assembly of inorganic nanoparticles has emerged as a powerful strategy for fabrication of stimuliresponsive drug delivery nanosystems.Herein,we designed and synthesized a series of lipoic acid-capped polysarcosine-bpolycaprolactone(PSar-b-PCL)block copolymers.The self-assembly of gold nanoparticles drove by these block copolymers was systematically investigated,and the preparation of near-infrared(NIR)light-responsive PSar-decorated gold nanovesicle(PSGV)was optimized.DOX as anticancer drug was efficiently encapsulated within the cavity of PSGV.The PSGV greatly prevented doxorubicin(DOX)from premature leakage.While upon 808 nm laser irradiation,most of loaded DOX was rapidly released,along with the recovery of DOX fluorescence.Impressively,the DOX-loaded PSGV(DOX-PSGV)exhibited much higher cell uptake efficiency when compared to DOX-loaded polyethylene glycol(PEG)-coated gold nanovesicle(DOX-PEGV).Thanks to the synergistic photothermal/chemo therapy,the DOX-PSGV had highly superior antitumor efficacy in established 4T1 tumor model.
基金supported by the National Science Fund for Distinguished Young Scholars(21625401)the National Natural Science Foundation of China(21701086 and 21971114)+1 种基金the Jiangsu Provincial Natural Science Foundation of China(BK20200090)the China-Sweden Joint Mobility Project(51811530018).
文摘The one-pot combination of biocatalytic and chemocatalytic reactions represents an economically and ecologically attractive concept in the emerging cascade processes for manufacturing.The mutual incompatibility of biocatalysis and chemocatalysis,however,usually causes the deactivation of catalysts,the mismatching of reaction dynamic,and further challenges their integration into concurrent chemo-biocascades.Herein,we have developed a convenient strategy to construct versatile functional metal-organic framework micro-nanoreactors(MOF-MNRs),which can realize not only the encapsulation and protection of biocatalysts but also the controllable transmission of substances and the mutual communication of the incompatible chemo-biosystems.Importantly,the MOFs serving as the shell of MNRs have the capability of enriching the chemocatalysts on the surface and improving the activity of the chemocatalysts to sufficiently match the optimum aqueous reaction system of biocatalysts,which greatly increase the efficiency in the combined concurrent chemo-biocatalysis.Such strategy of constructing MOF-MNRs provides a unique platform for connecting the“two worlds”of chemocatalysis and biocatalysis.
