There is growing interest in introducing ecological risks(ERs)and ecosystem services(ESs)into environmental policies and practices.However,the integration of ESs and ERs into actual decision-making remains insufficien...There is growing interest in introducing ecological risks(ERs)and ecosystem services(ESs)into environmental policies and practices.However,the integration of ESs and ERs into actual decision-making remains insufficient.We simulated the spatiotemporal dynamics of ESs(e.g.,carbon storage,water yield,habitat quality,and soil conservation)and ERs in the upper reach of the Yellow River(URYR)from 2000 to 2100.Additionally,we explored their relationships by combining the InVEST model and a landscape ecological risk model with CMIP6 data.Our main findings showed that regional ERs change in response to land use and environmental dynamics.Specifically,the ER area decreased by 27,673 m^(2)during 2000-2020,but it is projected to increase by 13,273,438,and 68 m^(2)under the SSP1-2.6,SSP2-4.5,and SSP5-8.5 scenarios,respectively.We also observed remarkable spatial differences in ESs and ERs between past and future scenarios.For instance,the source area of the URYR exhibited high ESs and low ERs(P<0.001),while the ESs and ERs are declining and increasing,respectively,in the northeastern URYR(P<0.05).Finally,we proposed a spatial optimization framework to improve ESs and reduce ERs,which will support regional sustainable development.展开更多
At present,simultaneous localization and mapping(SLAM) for an autonomous underwater vehicle(AUV)is a research hotspot.Aiming at the problem of non-linear model and non-Gaussian noise in AUV motion,an improved method o...At present,simultaneous localization and mapping(SLAM) for an autonomous underwater vehicle(AUV)is a research hotspot.Aiming at the problem of non-linear model and non-Gaussian noise in AUV motion,an improved method of variance reduction fast simultaneous localization and mapping(FastSLAM) with simulated annealing is proposed to solve the problems of particle degradation,particle depletion and particle loss in traditional FastSLAM,which lead to the reduction of AUV location estimation accuracy.The adaptive exponential fading factor is generated by the anneal function of simulated annealing algorithm to improve the effective particle number and replace resampling.By increasing the weight of small particles and decreasing the weight of large particles,the variance of particle weight can be reduced,the number of effective particles can be increased,and the accuracy of AUV location and feature location estimation can be improved to some extent by retaining more information carried by particles.The experimental results based on trial data show that the proposed simulated annealing variance reduction FastSLAM method avoids particle degradation,maintains the diversity of particles,weakened the degeneracy and improves the accuracy and stability of AUV navigation and localization system.展开更多
diabetes mellitus(DM)is a disease syndrome characterized by chronic hyperglycaemia.A long-term high-glucose environment leads to reactive oxygen species(ROS)production and nuclear DNA damage.human umbilical cord mesen...diabetes mellitus(DM)is a disease syndrome characterized by chronic hyperglycaemia.A long-term high-glucose environment leads to reactive oxygen species(ROS)production and nuclear DNA damage.human umbilical cord mesenchymal stem cell(HUcMSC)infusion induces significant antidiabetic effects in type 2 diabetes mellitus(T2DM)rats.Insulin-like growth factor 1(IGF1)receptor(IGF1R)is important in promoting glucose metabolism in diabetes;however,the mechanism by which HUcMSC can treat diabetes through IGF1R and DNA damage repair remains unclear.In this study,a DM rat model was induced with high-fat diet feeding and streptozotocin(STZ)administration and rats were infused four times with HUcMSC.Blood glucose,interleukin-6(IL-6),IL-10,glomerular basement membrane,and renal function were examined.Proteins that interacted with IGF1R were determined through coimmunoprecipitation assays.The expression of IGF1R,phosphorylated checkpoint kinase 2(p-CHK2),and phosphorylated protein 53(p-p53)was examined using immunohistochemistry(IHC)and western blot analysis.Enzyme-linked immunosorbent assay(ELISA)was used to determine the serum levels of 8-hydroxydeoxyguanosine(8-OHdG).Flow cytometry experiments were used to detect the surface markers of HUcMSC.The identification of the morphology and phenotype of HUcMSC was performed by way of oil red“O”staining and Alizarin red staining.DM rats exhibited abnormal blood glucose and IL-6/10 levels and renal function changes in the glomerular basement membrane,increased the expression of IGF1 and IGF1R.IGF1R interacted with CHK2,and the expression of p-CHK2 was significantly decreased in IGF1R-knockdown cells.When cisplatin was used to induce DNA damage,the expression of p-CHK2 was higher than that in the IGF1R-knockdown group without cisplatin treatment.HUcMSC infusion ameliorated abnormalities and preserved kidney structure and function in DM rats.The expression of IGF1,IGF1R,p-CHK2,and p-p53,and the level of 8-OHdG in the DM group increased significantly compared with those in the control group,and decreased after HUcMSC treatment.Our results suggested that IGF1R could interact with CHK2 and mediate DNA damage.HUcMSC infusion protected against kidney injury in DM rats.The underlying mechanisms may include HUcMSC-mediated enhancement of diabetes treatment via the IGF1R-CHK2-p53 signalling pathway.展开更多
Objective This study elucidated the function and role of SUMOylation in type Ⅰ endometrial carcinoma.Methods Fifty type Ⅰ endometrial carcinoma cases and para-cancer tissue samples were collected.The expression leve...Objective This study elucidated the function and role of SUMOylation in type Ⅰ endometrial carcinoma.Methods Fifty type Ⅰ endometrial carcinoma cases and para-cancer tissue samples were collected.The expression levels of ubiquitin-conjugating enzyme E2I(Ube2 i,Ubc9) and small ubiquitin-like modifier 1(SUMO1)/sentrin-specific peptidase 1(SENP1) proteins were examined using immunohistochemistry and the correlation with clinicopathological parameters was analyzed.Results Ubc9 expression in type Ⅰ endometrial carcinoma tissues was significantly higher than that in the para-cancer tissues;in contrast,the expression of the SENP1 protein was markedly lower than that in the para-cancer tissues.Ubc9 and SENP1 expression levels were negatively correlated and were associated with tumor differentiation,but not age,depth of invasion,tumor stage,and lymph node metastasis.Conclusion SUMOylation modification plays a major role in the pathogenesis and development of type Ⅰ endometrial carcinoma.Thus,it could be a potential target for the treatment of endometrial cancer.展开更多
Immunotherapy offers the promise of a potential cure for cancer,yet achieving the desired therapeutic effect can be challenging due to the immunosuppressive tumor microenvironments(TMEs) present in some tumors.Therefo...Immunotherapy offers the promise of a potential cure for cancer,yet achieving the desired therapeutic effect can be challenging due to the immunosuppressive tumor microenvironments(TMEs) present in some tumors.Therefore,robust immune system activation is crucial to enhance the efficacy of cancer immunotherapy in clinical applications.Bacteria have shown the ability to target the hypoxic TMEs while activating both innate and adaptive immune responses.Engineered bacteria,modified through chemical or biological methods,can be endowed with specific physiological properties,such as diverse surface antigens,metabolites,and improved biocompatibility.These unique characteristics give engineered bacteria distinct advantages in stimulating anti-cancer immune responses.This review explores the potential regulatory mechanisms of engineered bacteria in modulating both innate and adaptive immunity while also forecasting the future development and challenges of using engineered bacteria in clinical cancer immunotherapy.展开更多
Grassland ecosystems are experiencing severe deterioration due to ongoing climate fluctuation and human disturbance.Although numerous research centers on the patterns,processes,and functioning of degraded grassland,th...Grassland ecosystems are experiencing severe deterioration due to ongoing climate fluctuation and human disturbance.Although numerous research centers on the patterns,processes,and functioning of degraded grassland,there is still a lack of standards for defining and assessing degraded grassland,which restricts the cognition of the degraded grassland mechanisms and restoration practices.Therefore,we review current grassland degradation research for the sake of the common definitions and assessment methods worldwide.Grassland degradation definitions are divided into three stages,including biotic/abiotic factors,ecosystem functions,and ecosystem services/sustainability,and further combine the concept of“nature’s contributions to people”with the definition of grassland degradation.Moreover,grassland degradation assessment methods and indicators are diverse across scales.Additionally,we systematically explore the climate change and social system factors that affect grassland degradation,and reveal that grassland management policies play an essential role in grassland degradation and restoration.Overall,this review advances our understanding of grassland degradation and calls for a unified and effective global definition and assessment criteria,which will contribute to the sustainable management of the grassland ecosystem.展开更多
DNA is the hereditary material in humans and almost all other organisms. It is essential for maintaining accurate transmission of genetic information. In the life cycle, DNA replication, cell division, or genome damag...DNA is the hereditary material in humans and almost all other organisms. It is essential for maintaining accurate transmission of genetic information. In the life cycle, DNA replication, cell division, or genome damage, including that caused by endogenous and exogenous agents, may cause DNA aberrations. Of all forms of DNA damage, DNA double-strand breaks(DSBs) are the most serious. If the repair function is defective, DNA damage may cause gene mutation, genome instability, and cell chromosome loss, which in turn can even lead to tumorigenesis. DNA damage can be repaired through multiple mechanisms. Homologous recombination(HR) and non-homologous end joining(NHEJ) are the two main repair mechanisms for DNA DSBs. Increasing amounts of evidence reveal that protein modifications play an essential role in DNA damage repair.Protein deubiquitination is a vital post-translational modification which removes ubiquitin molecules or polyubiquitinated chains from substrates in order to reverse the ubiquitination reaction. This review discusses the role of deubiquitinating enzymes(DUBs) in repairing DNA DSBs. Exploring the molecular mechanisms of DUB regulation in DSB repair will provide new insights to combat human diseases and develop novel therapeutic approaches.展开更多
As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promot...As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric vehicles.However,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit model.Here,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance WPT.From the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time symmetry.Based on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time symmetry.Moreover,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection.Therefore,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.展开更多
DEHP(di(2-ethylhexyl) phthalate) is an endocrine disruptor commonly found in plastic products that has been associated with reproduction alterations, but the effect of DEHP on toxicity is still widely unknown. Using D...DEHP(di(2-ethylhexyl) phthalate) is an endocrine disruptor commonly found in plastic products that has been associated with reproduction alterations, but the effect of DEHP on toxicity is still widely unknown. Using DEHP concentrations of 10, 1, and 0.1 mg/L, we showed that DEHP reduced the reproductive capacity of Caenorhabditis elegans after 72 hr. of exposure. DEHP exposure reduced the reproductive capacity in terms of decreased brood sizes, egg hatchability(0.1, 1 and 10 mg/L), and egg-laying rate(1 and 10 mg/L), and increased numbers of fertilized eggs in the uterus(1 and 10 mg/L). DEHP also caused damage to gonad development. DEHP decreased the total number of germline cells, and decreased the relative area of the gonad arm of all exposure groups, with worms in the 1 mg/L DEHP exposure group having the minimum gonad arm area. Additionally, DEHP caused a significant concentration-dependent increase in the expression of unc-86. Autophagy and ROS contributed to the enhancement of DEHP toxicity in reducing reproductive capacity, and glutathione peroxidase and superoxide dismutase were activated as the antioxidant defense in this study. Hence, we found that DEHP has a dual effect on nematodes. Higher concentration(10 mg/L) DEHP can inhibit the expression of autophagy genes( atg-18, atg-7, bec-1, lgg-1 and unc-51), and lower concentrations(0.1 and 1 mg/L) can promote the expression of autophagy genes. Our data highlight the potential environmental risk of DEHP in inducing reproductive toxicity toward the gonad development and reproductive capacity of environmental organisms.展开更多
In this work,the high-energy-density plasmas(HEDP)evolved from joule-class-femtosecond-laser-irradiated nanowire-array(NWA)targets were numerically and experimentally studied.The results of particle-in-cell simulation...In this work,the high-energy-density plasmas(HEDP)evolved from joule-class-femtosecond-laser-irradiated nanowire-array(NWA)targets were numerically and experimentally studied.The results of particle-in-cell simulations indicate that ions accelerated in the sheath field around the surfaces of the nanowires are eventually confined in a plasma,contributing most to the high energy densities.The protons emitted from the front surfaces of the NWA targets provide rich information about the interactions that occur.We give the electron and ion energy densities for broad target parameter ranges.The ion energy densities from NWA targets were found to be an order of magnitude higher than those from planar targets,and the volume of the HEDP was several-fold greater.At optimal target parameters,8%of the laser energy can be converted to confined protons,and this results in ion energy densities at the GJ/cm^(3) level.In the experiments,the measured energy of the emitted protons reached 4 MeV,and the changes in energy with the NWA’s parameters were found to fit the simulation results well.Experimental measurements of neutrons from 2H(d,n)3He fusion with a yield of(24±18)×10^(6)/J from deuterated polyethylene NWA targets also confirmed these results.展开更多
Photonic and acoustic topological insulators exhibiting one-way transportation that is robust against defects and impurities are typically realized in coupled arrays of two-dimensional ring resonators.These systems ha...Photonic and acoustic topological insulators exhibiting one-way transportation that is robust against defects and impurities are typically realized in coupled arrays of two-dimensional ring resonators.These systems have produced a series of applications,including optical isolators,delay lines,and lasers.However,the structures are complicated because an additional coupler ring between neighboring rings is needed to construct photonic pseudospin.A photonic anomalous Floquet topological insulator is proposed and experimentally demonstrated in the microwave regime.This improved design takes advantage of the efficient and backward coupling of negative-index media.The results contribute to the understanding of topological structures in metamaterials and point toward a unique direction for constructing useful topological photonic devices.展开更多
看似简单实际却很复杂的乙硼烷(B_(2)H_(6),diborane)与氨(NH_(3))的反应已经困扰了硼化学家数十年。该反应在不同实验条件下可生成硼氢化二氢二氨合硼(III)([NH_(3)BH_(2)NH_(3)]BH_(4),diammoniate of diborane,DADB),氨硼烷(NH_(3)&#...看似简单实际却很复杂的乙硼烷(B_(2)H_(6),diborane)与氨(NH_(3))的反应已经困扰了硼化学家数十年。该反应在不同实验条件下可生成硼氢化二氢二氨合硼(III)([NH_(3)BH_(2)NH_(3)]BH_(4),diammoniate of diborane,DADB),氨硼烷(NH_(3)·BH_(3),ammonia borane,AB),氨基乙硼烷(NH_(2)B_(2)H_(5),aminodiborane,ADB)等化合物。从1923年起,化学家们对影响乙硼烷与路易斯碱反应的因素,如立体效应、诱导效应、溶剂效应、介电常数等进行研究,但一直无法根据上述影响因素准确预测产物。基于乙硼烷在THF中以THF·BH_(3)存在、路易斯碱与乙硼烷或THF·BH_(3)反应产物相同等实验事实,化学家们巧妙利用NH_(3)与THF·BH_(3)的反应,在温和的条件下研究了DADB、AB的生成机理,发现双氢键是控制反应的重要因素。利用AB与THF·BH_(3)的反应,实验和理论计算结果进一步揭示了基于双氢键的ADB的复杂形成机理。展开更多
Objective This study aimed to identify SPRR2A as a hub gene in endometrial cancer(EC)and explore its potential as a diagnostic and prognostic biomarker.Methods Bioinformatics analysis was performed on highthroughput s...Objective This study aimed to identify SPRR2A as a hub gene in endometrial cancer(EC)and explore its potential as a diagnostic and prognostic biomarker.Methods Bioinformatics analysis was performed on highthroughput sequencing datasets of EC cases from The Cancer Genome Atlas.Reverse-transcription-quantitative PCR validated the differential expression of SPRR2A in EC cell lines and tissues.Results Compared with normal cells and adjacent tissues,EC cells and tissues showed significantly upregulated SPRR2A expression(p<0.05).High SPRR2A expression was associated with poor prognosis in EC patients(HR=1.52,95%CI 1.00 to 2.30,p=0.048).Furthermore,the expression levels of SPRR2A varied across histological grades,being significantly lower in G1 tumours than in G2 and G3 tumours.However,no significant differences in SPRR2A expression regarding age,clinical stage,tumour invasion or histological type were found.Conclusion SPRR2A is overexpressed in EC and serves as an independent predictor of poor prognosis.It may be a potential biomarker for EC diagnosis and prognosis.Further research is needed to explore its molecular mechanisms and clinical applications.展开更多
Metasurfaces with spin-selective transmission play an increasingly critical role in realizing optical chiral responses,especially for strong intrinsic chirality,which is limited to complex three-dimensional geometry.I...Metasurfaces with spin-selective transmission play an increasingly critical role in realizing optical chiral responses,especially for strong intrinsic chirality,which is limited to complex three-dimensional geometry.In this paper,we propose a planar metasurface capable of generating maximal intrinsic chirality and achieving dual-band spinselective transmission utilizing dual quasi-bound states in the continuum(quasi-BICs)caused by the structural symmetry breaking.Interestingly,the value of circular dichroism(CD)and the transmittance of two kinds of circular polarization states can be arbitrarily controlled by tuning the asymmetry parameter.Remarkable CD approaching unity with the maximum transmittance up to 0.95 is experimentally achieved in the dual band.Furthermore,assisted by chiral BICs,the application in polarization multiplexed near-field image display is also exhibited.Our work provides a new avenue to flexibly control intrinsic chirality in planar structure and offers an alternative strategy to develop chiral sensing,multiband spin-selective transmission,and high-performance circularly polarized wave detection.The basic principle and design method of our experiments in the microwave regime can be extended to other bands,such as the terahertz and infrared wavelengths.展开更多
Topological systems containing near-field or far-field couplings between unit cells have been widely investigated in quantum and classic systems.Their band structures are well explained with theories based on tight-bi...Topological systems containing near-field or far-field couplings between unit cells have been widely investigated in quantum and classic systems.Their band structures are well explained with theories based on tight-binding or multiple scattering formalism.However,characteristics of the topology of the bulk bands based on the joint modulation of near-field and far-field couplings are rarely studied.Such hybrid systems are hardly realized in real systems and cannot be described by neither tight-binding nor multiple scattering theories.Here,we propose a hybrid-coupling photonic topological insulator based on a quasi-1D dimerized chain with the coexistence of near-field coupling within the unit cell and far-field coupling among all sites.Both theoretical and experimental results show that topological transition is realized by introducing near-field coupling for given far-field coupling conditions.In addition to closing and reopening the bandgap,the change in near-field coupling modulates the effective mass of photonics in the upper band from positive to negative,leading to an indirect bandgap,which cannot be achieved in conventional dimerized chains with either far-field or near-field coupling only.展开更多
Recently,the concepts of parity–time(PT)symmetry and band topology have inspired many novel ideas for light manipulation in their respective directions.Here we propose and demonstrate a perfect light absorber with a ...Recently,the concepts of parity–time(PT)symmetry and band topology have inspired many novel ideas for light manipulation in their respective directions.Here we propose and demonstrate a perfect light absorber with a PT phase transition via coupled topological interface states(TISs),which combines the two concepts in a onedimensional photonic crystal heterostructure.By fine tuning the coupling between TISs,the PT phase transition is revealed by the evolution of absorption spectra in both ideal and non-ideal PT symmetry cases.Especially,in the ideal case,a perfect light absorber at an exceptional point with unidirectional invisibility is numerically obtained.In the non-ideal case,a perfect light absorber in a broken phase is experimentally realized,which verifies the possibility of tailoring non-Hermiticity by engineering the coupling.Our work paves the way for novel effects and functional devices from the exceptional point of coupled TISs,such as a unidirectional light absorber and exceptional-point sensor.展开更多
Magnetic resonance coupling plays an important role in the non-radiative wireless power transfer without cables.However,the basic near-field coupling also has some key limitations on the resonance wireless power trans...Magnetic resonance coupling plays an important role in the non-radiative wireless power transfer without cables.However,the basic near-field coupling also has some key limitations on the resonance wireless power transfer(WPT).On the one hand,when the transfer distance is short,the eigenfrequencies of the WPT system will split because of the strong near-field coupling between the resonance transmitter and receiver.On the other hand,although the working frequency is fixed for the long-distance case,the transfer efficiency will be significantly dropped for the weak coupling strength.Therefore,a long-captivated problem of the resonance WPT systems is that it is difficult to balance the fixed working frequency and high efficiency of the devices.In this work,we put forward the composite transmitter with a pair of resonance coils of different size.By assisting the rotational degrees of freedom in the composite transmitter,a high-order parity-time-symmetric non-Hermitian system can be established.Especially,in contrast to the conventional resonance WPT scheme,the robust WPT can maintain fixed working frequency and efficiency over a varying transfer distance in the optimized WPT system with composite transmitter,since this eigenfrequency is insensitive to the operational conditions.Our findings demonstrate that the composite transmitter possesses better performance for WPT than its single counterpart,offering the opportunities for engineering novel designer electromagnetic transfer states with unique robustness.展开更多
Wireless power transfer(WPT)offers significant advantages,particularly due to its flexibility,enabling diverse applications.However,conventional single-transmitter,single-receiver systems are limited by their sensitiv...Wireless power transfer(WPT)offers significant advantages,particularly due to its flexibility,enabling diverse applications.However,conventional single-transmitter,single-receiver systems are limited by their sensitivity to lateral disturbances,frequency instability,and strict distance constraints.Recently,multiple-transmitter,single-receiver(MTSR)systems have gained attention for their potential to enhance system flexibility and reliability.In this work,we propose an efficient second-order anti-parity‒time(anti-PT)symmetry by introducing two transmitters that simultaneously exchange energy with the external channel.This concept is further extended to third-order anti-PT symmetry for efficient WPT in MTSR systems.By leveraging interference between shared sources,we construct virtual coupling instead of relying on traditional resistive losses.Remarkably,our system maintains frequency stability,broad bandwidth,and robust high-efficiency power transfer even when the resonant frequencies of the transmitter and receiver coils are mismatched.This innovation challenges conventional understanding and opens new directions for WPT technology.展开更多
Optical resonators with high quality(Q)factors are paramount for the enhancement of light–matter interactions in engineered photonic structures,but their performance always suffers from the scattering loss caused by ...Optical resonators with high quality(Q)factors are paramount for the enhancement of light–matter interactions in engineered photonic structures,but their performance always suffers from the scattering loss caused by fabrication imperfections.Merging bound states in the continuum(BICs)provide us with a nontrivial physical mechanism to overcome this challenge,as they can significantly improve the Q factors of quasi-BICs.However,most of the reported merging BICs are found atΓpoint(the center of the Brillouin zone),which intensively limits many potential applications based on angular selectivity.To date,studies on manipulating merging BICs at off-Γpoint are always accompanied by the breaking of structural symmetry that inevitably increases process difficulty and structural defects to a certain extent.Here,we propose a scheme to construct merging BICs at almost an arbitrary point in momentum space without breaking symmetry.Enabled by the topological features of BICs,we merge four accidental BICs with one symmetry-protected BIC at theΓpoint and merge two accidental BICs with opposite topological charges at the off-Γpoint only by changing the periodic constant of a photonic crystal slab.Furthermore,the position of off-Γmerging BICs can be flexibly tuned by the periodic constant and height of the structure simultaneously.Interestingly,it is observed that the movement of BICs occurs in a quasi-flatband with ultra-narrow bandwidth.Therefore,merging BICs in a tiny band provide a mechanism to realize more robust ultrahigh-Q resonances that further improve the optical performance,which is limited by wide-angle illuminations.Finally,as an example of application,effective angle-insensitive second-harmonic generation assisted by different quasi-BICs is numerically demonstrated.Our findings demonstrate momentum-steerable merging BICs in a quasi-flatband,which may expand the application of BICs to the enhancement of frequency-sensitive light–matter interaction with angular selectivity.展开更多
基金supported by the Ecological Conservation and High-Quality Development of the Yellow River Basin Program,China(2022-YRUC-010102)the Second Tibetan Plateau Scientific Expedition and Research Program,China(20190ZKK0405)the Basic Research Fund Project of Innovation Team of Novel Forage Germplasm and Sustainable Utilization of Grassland Resources,China(BR22-12-07)。
文摘There is growing interest in introducing ecological risks(ERs)and ecosystem services(ESs)into environmental policies and practices.However,the integration of ESs and ERs into actual decision-making remains insufficient.We simulated the spatiotemporal dynamics of ESs(e.g.,carbon storage,water yield,habitat quality,and soil conservation)and ERs in the upper reach of the Yellow River(URYR)from 2000 to 2100.Additionally,we explored their relationships by combining the InVEST model and a landscape ecological risk model with CMIP6 data.Our main findings showed that regional ERs change in response to land use and environmental dynamics.Specifically,the ER area decreased by 27,673 m^(2)during 2000-2020,but it is projected to increase by 13,273,438,and 68 m^(2)under the SSP1-2.6,SSP2-4.5,and SSP5-8.5 scenarios,respectively.We also observed remarkable spatial differences in ESs and ERs between past and future scenarios.For instance,the source area of the URYR exhibited high ESs and low ERs(P<0.001),while the ESs and ERs are declining and increasing,respectively,in the northeastern URYR(P<0.05).Finally,we proposed a spatial optimization framework to improve ESs and reduce ERs,which will support regional sustainable development.
基金supported by the National Science Fund of China under Grants 61603034China Postdoctoral Science Foundation under Grant 2019M653870XB+1 种基金Beijing Municipal Natural Science Foundation (3182027)Fundamental Research Funds for the Central Universities,China,FRF-GF-17-B44,and XJS191315
文摘At present,simultaneous localization and mapping(SLAM) for an autonomous underwater vehicle(AUV)is a research hotspot.Aiming at the problem of non-linear model and non-Gaussian noise in AUV motion,an improved method of variance reduction fast simultaneous localization and mapping(FastSLAM) with simulated annealing is proposed to solve the problems of particle degradation,particle depletion and particle loss in traditional FastSLAM,which lead to the reduction of AUV location estimation accuracy.The adaptive exponential fading factor is generated by the anneal function of simulated annealing algorithm to improve the effective particle number and replace resampling.By increasing the weight of small particles and decreasing the weight of large particles,the variance of particle weight can be reduced,the number of effective particles can be increased,and the accuracy of AUV location and feature location estimation can be improved to some extent by retaining more information carried by particles.The experimental results based on trial data show that the proposed simulated annealing variance reduction FastSLAM method avoids particle degradation,maintains the diversity of particles,weakened the degeneracy and improves the accuracy and stability of AUV navigation and localization system.
基金supported by the Peak Disciplines(Type IV)of Institutions of Higher Learning in Shanghai,the Discipline Leader Program of Pudong New District Health and Family Planning Commission(No.PWRd2018-02)the Natural Science Foundation of Jiangxi Province(Nos.20181ACB20021 and 20181BAB205044),China.
文摘diabetes mellitus(DM)is a disease syndrome characterized by chronic hyperglycaemia.A long-term high-glucose environment leads to reactive oxygen species(ROS)production and nuclear DNA damage.human umbilical cord mesenchymal stem cell(HUcMSC)infusion induces significant antidiabetic effects in type 2 diabetes mellitus(T2DM)rats.Insulin-like growth factor 1(IGF1)receptor(IGF1R)is important in promoting glucose metabolism in diabetes;however,the mechanism by which HUcMSC can treat diabetes through IGF1R and DNA damage repair remains unclear.In this study,a DM rat model was induced with high-fat diet feeding and streptozotocin(STZ)administration and rats were infused four times with HUcMSC.Blood glucose,interleukin-6(IL-6),IL-10,glomerular basement membrane,and renal function were examined.Proteins that interacted with IGF1R were determined through coimmunoprecipitation assays.The expression of IGF1R,phosphorylated checkpoint kinase 2(p-CHK2),and phosphorylated protein 53(p-p53)was examined using immunohistochemistry(IHC)and western blot analysis.Enzyme-linked immunosorbent assay(ELISA)was used to determine the serum levels of 8-hydroxydeoxyguanosine(8-OHdG).Flow cytometry experiments were used to detect the surface markers of HUcMSC.The identification of the morphology and phenotype of HUcMSC was performed by way of oil red“O”staining and Alizarin red staining.DM rats exhibited abnormal blood glucose and IL-6/10 levels and renal function changes in the glomerular basement membrane,increased the expression of IGF1 and IGF1R.IGF1R interacted with CHK2,and the expression of p-CHK2 was significantly decreased in IGF1R-knockdown cells.When cisplatin was used to induce DNA damage,the expression of p-CHK2 was higher than that in the IGF1R-knockdown group without cisplatin treatment.HUcMSC infusion ameliorated abnormalities and preserved kidney structure and function in DM rats.The expression of IGF1,IGF1R,p-CHK2,and p-p53,and the level of 8-OHdG in the DM group increased significantly compared with those in the control group,and decreased after HUcMSC treatment.Our results suggested that IGF1R could interact with CHK2 and mediate DNA damage.HUcMSC infusion protected against kidney injury in DM rats.The underlying mechanisms may include HUcMSC-mediated enhancement of diabetes treatment via the IGF1R-CHK2-p53 signalling pathway.
文摘Objective This study elucidated the function and role of SUMOylation in type Ⅰ endometrial carcinoma.Methods Fifty type Ⅰ endometrial carcinoma cases and para-cancer tissue samples were collected.The expression levels of ubiquitin-conjugating enzyme E2I(Ube2 i,Ubc9) and small ubiquitin-like modifier 1(SUMO1)/sentrin-specific peptidase 1(SENP1) proteins were examined using immunohistochemistry and the correlation with clinicopathological parameters was analyzed.Results Ubc9 expression in type Ⅰ endometrial carcinoma tissues was significantly higher than that in the para-cancer tissues;in contrast,the expression of the SENP1 protein was markedly lower than that in the para-cancer tissues.Ubc9 and SENP1 expression levels were negatively correlated and were associated with tumor differentiation,but not age,depth of invasion,tumor stage,and lymph node metastasis.Conclusion SUMOylation modification plays a major role in the pathogenesis and development of type Ⅰ endometrial carcinoma.Thus,it could be a potential target for the treatment of endometrial cancer.
基金supported by the Science and Technology Research Project of Jilin Education Bureau(No.JJKH20230804KJ)。
文摘Immunotherapy offers the promise of a potential cure for cancer,yet achieving the desired therapeutic effect can be challenging due to the immunosuppressive tumor microenvironments(TMEs) present in some tumors.Therefore,robust immune system activation is crucial to enhance the efficacy of cancer immunotherapy in clinical applications.Bacteria have shown the ability to target the hypoxic TMEs while activating both innate and adaptive immune responses.Engineered bacteria,modified through chemical or biological methods,can be endowed with specific physiological properties,such as diverse surface antigens,metabolites,and improved biocompatibility.These unique characteristics give engineered bacteria distinct advantages in stimulating anti-cancer immune responses.This review explores the potential regulatory mechanisms of engineered bacteria in modulating both innate and adaptive immunity while also forecasting the future development and challenges of using engineered bacteria in clinical cancer immunotherapy.
基金supported by the Talent introduction program of Chinese Academy of Sciences,Institute of Tibetan Plateau Research.
文摘Grassland ecosystems are experiencing severe deterioration due to ongoing climate fluctuation and human disturbance.Although numerous research centers on the patterns,processes,and functioning of degraded grassland,there is still a lack of standards for defining and assessing degraded grassland,which restricts the cognition of the degraded grassland mechanisms and restoration practices.Therefore,we review current grassland degradation research for the sake of the common definitions and assessment methods worldwide.Grassland degradation definitions are divided into three stages,including biotic/abiotic factors,ecosystem functions,and ecosystem services/sustainability,and further combine the concept of“nature’s contributions to people”with the definition of grassland degradation.Moreover,grassland degradation assessment methods and indicators are diverse across scales.Additionally,we systematically explore the climate change and social system factors that affect grassland degradation,and reveal that grassland management policies play an essential role in grassland degradation and restoration.Overall,this review advances our understanding of grassland degradation and calls for a unified and effective global definition and assessment criteria,which will contribute to the sustainable management of the grassland ecosystem.
基金supported by the National Natural Science Foundation of China (Nos. 91749115 and 81872298)the Natural Science Foundation of Jiangxi Province (No. 20181BAB205044), China。
文摘DNA is the hereditary material in humans and almost all other organisms. It is essential for maintaining accurate transmission of genetic information. In the life cycle, DNA replication, cell division, or genome damage, including that caused by endogenous and exogenous agents, may cause DNA aberrations. Of all forms of DNA damage, DNA double-strand breaks(DSBs) are the most serious. If the repair function is defective, DNA damage may cause gene mutation, genome instability, and cell chromosome loss, which in turn can even lead to tumorigenesis. DNA damage can be repaired through multiple mechanisms. Homologous recombination(HR) and non-homologous end joining(NHEJ) are the two main repair mechanisms for DNA DSBs. Increasing amounts of evidence reveal that protein modifications play an essential role in DNA damage repair.Protein deubiquitination is a vital post-translational modification which removes ubiquitin molecules or polyubiquitinated chains from substrates in order to reverse the ubiquitination reaction. This review discusses the role of deubiquitinating enzymes(DUBs) in repairing DNA DSBs. Exploring the molecular mechanisms of DUB regulation in DSB repair will provide new insights to combat human diseases and develop novel therapeutic approaches.
基金supported by the National Key Research and Development Program of China (Grant No. 2016YFA0301101)the National Natural Science Foundation of China (Grant Nos. 91850206, 61621001, 2004284, 11674247, and 11974261)+3 种基金Shanghai Science and Technology Committee, China (Grant Nos. 18JC1410900 and 18ZR1442900)the China Postdoctoral Science Foundation (Grant Nos. 2019TQ0232 and 2019M661605)the Shanghai Super Postdoctoral Incentive ProgramFundamental Research Funds for the Central Universities, China
文摘As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric vehicles.However,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit model.Here,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance WPT.From the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time symmetry.Based on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time symmetry.Moreover,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection.Therefore,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.
基金supported by the Fundamental Research Fund of Central Public Welfare Research Institutions in 2019(Innovation team project of new approach and application on substitution toxicology of environmental hormone substances).
文摘DEHP(di(2-ethylhexyl) phthalate) is an endocrine disruptor commonly found in plastic products that has been associated with reproduction alterations, but the effect of DEHP on toxicity is still widely unknown. Using DEHP concentrations of 10, 1, and 0.1 mg/L, we showed that DEHP reduced the reproductive capacity of Caenorhabditis elegans after 72 hr. of exposure. DEHP exposure reduced the reproductive capacity in terms of decreased brood sizes, egg hatchability(0.1, 1 and 10 mg/L), and egg-laying rate(1 and 10 mg/L), and increased numbers of fertilized eggs in the uterus(1 and 10 mg/L). DEHP also caused damage to gonad development. DEHP decreased the total number of germline cells, and decreased the relative area of the gonad arm of all exposure groups, with worms in the 1 mg/L DEHP exposure group having the minimum gonad arm area. Additionally, DEHP caused a significant concentration-dependent increase in the expression of unc-86. Autophagy and ROS contributed to the enhancement of DEHP toxicity in reducing reproductive capacity, and glutathione peroxidase and superoxide dismutase were activated as the antioxidant defense in this study. Hence, we found that DEHP has a dual effect on nematodes. Higher concentration(10 mg/L) DEHP can inhibit the expression of autophagy genes( atg-18, atg-7, bec-1, lgg-1 and unc-51), and lower concentrations(0.1 and 1 mg/L) can promote the expression of autophagy genes. Our data highlight the potential environmental risk of DEHP in inducing reproductive toxicity toward the gonad development and reproductive capacity of environmental organisms.
基金This work was supported by the NSFC innovation group project(Grant No.11921006)the National Grand Instrument Project(Grant No.2019YFF01014402)+1 种基金the United States Department of Energy(Grant No.DE-FG03-93ER40773)the NNSA(Grant No.DENA0003841)(CENTAUR).The PIC simulations were carried out using the High-Performance Computing Platform of Peking University。
文摘In this work,the high-energy-density plasmas(HEDP)evolved from joule-class-femtosecond-laser-irradiated nanowire-array(NWA)targets were numerically and experimentally studied.The results of particle-in-cell simulations indicate that ions accelerated in the sheath field around the surfaces of the nanowires are eventually confined in a plasma,contributing most to the high energy densities.The protons emitted from the front surfaces of the NWA targets provide rich information about the interactions that occur.We give the electron and ion energy densities for broad target parameter ranges.The ion energy densities from NWA targets were found to be an order of magnitude higher than those from planar targets,and the volume of the HEDP was several-fold greater.At optimal target parameters,8%of the laser energy can be converted to confined protons,and this results in ion energy densities at the GJ/cm^(3) level.In the experiments,the measured energy of the emitted protons reached 4 MeV,and the changes in energy with the NWA’s parameters were found to fit the simulation results well.Experimental measurements of neutrons from 2H(d,n)3He fusion with a yield of(24±18)×10^(6)/J from deuterated polyethylene NWA targets also confirmed these results.
基金the financial support from the National Key R&D Program of China(Grant No.2021YFA1400602)the National Natural Science Foundation of China(Grant Nos.12004284,11974261,91850206,and 61621001)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.22120210579)the Shanghai Chenguang Plan(Grant No.21CGA22).
文摘Photonic and acoustic topological insulators exhibiting one-way transportation that is robust against defects and impurities are typically realized in coupled arrays of two-dimensional ring resonators.These systems have produced a series of applications,including optical isolators,delay lines,and lasers.However,the structures are complicated because an additional coupler ring between neighboring rings is needed to construct photonic pseudospin.A photonic anomalous Floquet topological insulator is proposed and experimentally demonstrated in the microwave regime.This improved design takes advantage of the efficient and backward coupling of negative-index media.The results contribute to the understanding of topological structures in metamaterials and point toward a unique direction for constructing useful topological photonic devices.
文摘看似简单实际却很复杂的乙硼烷(B_(2)H_(6),diborane)与氨(NH_(3))的反应已经困扰了硼化学家数十年。该反应在不同实验条件下可生成硼氢化二氢二氨合硼(III)([NH_(3)BH_(2)NH_(3)]BH_(4),diammoniate of diborane,DADB),氨硼烷(NH_(3)·BH_(3),ammonia borane,AB),氨基乙硼烷(NH_(2)B_(2)H_(5),aminodiborane,ADB)等化合物。从1923年起,化学家们对影响乙硼烷与路易斯碱反应的因素,如立体效应、诱导效应、溶剂效应、介电常数等进行研究,但一直无法根据上述影响因素准确预测产物。基于乙硼烷在THF中以THF·BH_(3)存在、路易斯碱与乙硼烷或THF·BH_(3)反应产物相同等实验事实,化学家们巧妙利用NH_(3)与THF·BH_(3)的反应,在温和的条件下研究了DADB、AB的生成机理,发现双氢键是控制反应的重要因素。利用AB与THF·BH_(3)的反应,实验和理论计算结果进一步揭示了基于双氢键的ADB的复杂形成机理。
基金funded by Beijing Xisike Clinical Oncology Research Foundation,grant number Y-2019AZQN-1049.
文摘Objective This study aimed to identify SPRR2A as a hub gene in endometrial cancer(EC)and explore its potential as a diagnostic and prognostic biomarker.Methods Bioinformatics analysis was performed on highthroughput sequencing datasets of EC cases from The Cancer Genome Atlas.Reverse-transcription-quantitative PCR validated the differential expression of SPRR2A in EC cell lines and tissues.Results Compared with normal cells and adjacent tissues,EC cells and tissues showed significantly upregulated SPRR2A expression(p<0.05).High SPRR2A expression was associated with poor prognosis in EC patients(HR=1.52,95%CI 1.00 to 2.30,p=0.048).Furthermore,the expression levels of SPRR2A varied across histological grades,being significantly lower in G1 tumours than in G2 and G3 tumours.However,no significant differences in SPRR2A expression regarding age,clinical stage,tumour invasion or histological type were found.Conclusion SPRR2A is overexpressed in EC and serves as an independent predictor of poor prognosis.It may be a potential biomarker for EC diagnosis and prognosis.Further research is needed to explore its molecular mechanisms and clinical applications.
基金National Key Research and Development Program of China(2021YFA1400602)National Natural Science Foundation of China(11974261,62075213,12104105,12274325,11874286,61621001,91850206)。
文摘Metasurfaces with spin-selective transmission play an increasingly critical role in realizing optical chiral responses,especially for strong intrinsic chirality,which is limited to complex three-dimensional geometry.In this paper,we propose a planar metasurface capable of generating maximal intrinsic chirality and achieving dual-band spinselective transmission utilizing dual quasi-bound states in the continuum(quasi-BICs)caused by the structural symmetry breaking.Interestingly,the value of circular dichroism(CD)and the transmittance of two kinds of circular polarization states can be arbitrarily controlled by tuning the asymmetry parameter.Remarkable CD approaching unity with the maximum transmittance up to 0.95 is experimentally achieved in the dual band.Furthermore,assisted by chiral BICs,the application in polarization multiplexed near-field image display is also exhibited.Our work provides a new avenue to flexibly control intrinsic chirality in planar structure and offers an alternative strategy to develop chiral sensing,multiband spin-selective transmission,and high-performance circularly polarized wave detection.The basic principle and design method of our experiments in the microwave regime can be extended to other bands,such as the terahertz and infrared wavelengths.
基金National Key Research and Development Program of China(2020YFA0211400,2020YFA0211402)National Natural Science Foundation of China(91850206,11974261,61621001,12104105)+1 种基金Shanghai Pujiang Program(21PJ1411400)Fundamental Research Funds for the Central Universities。
文摘Topological systems containing near-field or far-field couplings between unit cells have been widely investigated in quantum and classic systems.Their band structures are well explained with theories based on tight-binding or multiple scattering formalism.However,characteristics of the topology of the bulk bands based on the joint modulation of near-field and far-field couplings are rarely studied.Such hybrid systems are hardly realized in real systems and cannot be described by neither tight-binding nor multiple scattering theories.Here,we propose a hybrid-coupling photonic topological insulator based on a quasi-1D dimerized chain with the coexistence of near-field coupling within the unit cell and far-field coupling among all sites.Both theoretical and experimental results show that topological transition is realized by introducing near-field coupling for given far-field coupling conditions.In addition to closing and reopening the bandgap,the change in near-field coupling modulates the effective mass of photonics in the upper band from positive to negative,leading to an indirect bandgap,which cannot be achieved in conventional dimerized chains with either far-field or near-field coupling only.
基金National Key Research and Development Program of China(2021YFA1400602)National Natural Science Foundation of China(11974261,12275161,61621001,62075213,91850206)Fundamental Research Funds for the Central Universities(22120190222)。
文摘Recently,the concepts of parity–time(PT)symmetry and band topology have inspired many novel ideas for light manipulation in their respective directions.Here we propose and demonstrate a perfect light absorber with a PT phase transition via coupled topological interface states(TISs),which combines the two concepts in a onedimensional photonic crystal heterostructure.By fine tuning the coupling between TISs,the PT phase transition is revealed by the evolution of absorption spectra in both ideal and non-ideal PT symmetry cases.Especially,in the ideal case,a perfect light absorber at an exceptional point with unidirectional invisibility is numerically obtained.In the non-ideal case,a perfect light absorber in a broken phase is experimentally realized,which verifies the possibility of tailoring non-Hermiticity by engineering the coupling.Our work paves the way for novel effects and functional devices from the exceptional point of coupled TISs,such as a unidirectional light absorber and exceptional-point sensor.
基金supported by the National Key R&D Program of China(2021YFA1400602)the National Natural Science Foundation of China(12004284)+1 种基金the Fundamental Research Funds for the Central Universities(22120210579)the Chenguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(21CGA22).
文摘Magnetic resonance coupling plays an important role in the non-radiative wireless power transfer without cables.However,the basic near-field coupling also has some key limitations on the resonance wireless power transfer(WPT).On the one hand,when the transfer distance is short,the eigenfrequencies of the WPT system will split because of the strong near-field coupling between the resonance transmitter and receiver.On the other hand,although the working frequency is fixed for the long-distance case,the transfer efficiency will be significantly dropped for the weak coupling strength.Therefore,a long-captivated problem of the resonance WPT systems is that it is difficult to balance the fixed working frequency and high efficiency of the devices.In this work,we put forward the composite transmitter with a pair of resonance coils of different size.By assisting the rotational degrees of freedom in the composite transmitter,a high-order parity-time-symmetric non-Hermitian system can be established.Especially,in contrast to the conventional resonance WPT scheme,the robust WPT can maintain fixed working frequency and efficiency over a varying transfer distance in the optimized WPT system with composite transmitter,since this eigenfrequency is insensitive to the operational conditions.Our findings demonstrate that the composite transmitter possesses better performance for WPT than its single counterpart,offering the opportunities for engineering novel designer electromagnetic transfer states with unique robustness.
基金supported by the National Key R&D Program of China(Nos.2021YFA1400602 and 2023YFA1407600)the National Natural Science Foundation of China(Nos.12374294 and 52477014)the Chenguang Program of Shanghai(No.21CGA22).
文摘Wireless power transfer(WPT)offers significant advantages,particularly due to its flexibility,enabling diverse applications.However,conventional single-transmitter,single-receiver systems are limited by their sensitivity to lateral disturbances,frequency instability,and strict distance constraints.Recently,multiple-transmitter,single-receiver(MTSR)systems have gained attention for their potential to enhance system flexibility and reliability.In this work,we propose an efficient second-order anti-parity‒time(anti-PT)symmetry by introducing two transmitters that simultaneously exchange energy with the external channel.This concept is further extended to third-order anti-PT symmetry for efficient WPT in MTSR systems.By leveraging interference between shared sources,we construct virtual coupling instead of relying on traditional resistive losses.Remarkably,our system maintains frequency stability,broad bandwidth,and robust high-efficiency power transfer even when the resonant frequencies of the transmitter and receiver coils are mismatched.This innovation challenges conventional understanding and opens new directions for WPT technology.
基金National Key Research and Development Program of China (2021YFA1400602)National Natural Science Foundation of China (11974261,12104105,12274325,61621001,62075213,91850206)Fundamental Research Funds for the Central Universities (22120190222)。
文摘Optical resonators with high quality(Q)factors are paramount for the enhancement of light–matter interactions in engineered photonic structures,but their performance always suffers from the scattering loss caused by fabrication imperfections.Merging bound states in the continuum(BICs)provide us with a nontrivial physical mechanism to overcome this challenge,as they can significantly improve the Q factors of quasi-BICs.However,most of the reported merging BICs are found atΓpoint(the center of the Brillouin zone),which intensively limits many potential applications based on angular selectivity.To date,studies on manipulating merging BICs at off-Γpoint are always accompanied by the breaking of structural symmetry that inevitably increases process difficulty and structural defects to a certain extent.Here,we propose a scheme to construct merging BICs at almost an arbitrary point in momentum space without breaking symmetry.Enabled by the topological features of BICs,we merge four accidental BICs with one symmetry-protected BIC at theΓpoint and merge two accidental BICs with opposite topological charges at the off-Γpoint only by changing the periodic constant of a photonic crystal slab.Furthermore,the position of off-Γmerging BICs can be flexibly tuned by the periodic constant and height of the structure simultaneously.Interestingly,it is observed that the movement of BICs occurs in a quasi-flatband with ultra-narrow bandwidth.Therefore,merging BICs in a tiny band provide a mechanism to realize more robust ultrahigh-Q resonances that further improve the optical performance,which is limited by wide-angle illuminations.Finally,as an example of application,effective angle-insensitive second-harmonic generation assisted by different quasi-BICs is numerically demonstrated.Our findings demonstrate momentum-steerable merging BICs in a quasi-flatband,which may expand the application of BICs to the enhancement of frequency-sensitive light–matter interaction with angular selectivity.
