Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we develop...Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we developed a bacterial type-II toxin-antitoxin-mediated method to manipulate genomic integration of tandem gene repeats in Saccharomyces cerevisiae and further visualised the evolutionary trajectories of gene repeats.We designed a tri-vector system to introduce toxin-antitoxin-driven gene amplification modules.Results:This system delivered multi-copy gene integration in the form of tandem gene repeats spontaneously and independently from toxin-antitoxin-mediated selection.Inducing the toxin(RelE)expressing via a copper(II)-inducible CUP1 promoter successfully drove the in-situ gene amplification of the antitoxin(RelB)module,resulting in~40 copies of a green fluorescence reporter gene per copy of genome.Copy-number changes,copy-number increase and copy-number decrease,and stable maintenance were visualised using the green fluorescence protein and blue chromoprotein AeBlue as reporters.Copy-number increases happened spontaneously and independent on a selection pressure.Increased copy number was quickly enriched through toxin-antitoxin-mediated selection.Conclusion:In summary,the bacterial toxin-antitoxin systems provide a flexible mechanism to manipulate gene copy number in eukaryotic cells and can be exploited for synthetic biology and metabolic engineering applications.展开更多
Tire-derived aggregate(TDA)is an engineered construction material produced from recycled scrap tires and is often used as a compressible layer overlying buried structures to reduce overburden loads.The potential ampli...Tire-derived aggregate(TDA)is an engineered construction material produced from recycled scrap tires and is often used as a compressible layer overlying buried structures to reduce overburden loads.The potential amplification of ground motion in a tunnel site is well understood,but the effect of the tunnel-TDA layer system on ground surface acceleration remains unclear.In this study,both linear and nonlinear dynamic analyses were performed to evaluate the contributions of a TDA layer to the acceleration amplification at the ground surface.The numerical model was calibrated using recorded data from a shaking table test and validated against the literature results,followed by extensive parametric studies.The mechanical and geometrical parameters investigated for the TDA layer included damping ratio,density,Young’s modulus,width,thickness,and depth.The predominant frequency and intensity level of input motions were also investigated.This study showed that the presence of the TDA layer provided an additional acceleration amplification effect.The amplification was more pronounced in areas above the tunnel,particularly for the wider and shallower TDA layer subjected to high frequency and low intensity input motions.展开更多
Co-assembling chiral molecules with achiral compounds via non-covalent interactions like areneperfluoroarene(AP) interactions offers an effective approach for fabricating chiral functional materials.Herein,chiral mole...Co-assembling chiral molecules with achiral compounds via non-covalent interactions like areneperfluoroarene(AP) interactions offers an effective approach for fabricating chiral functional materials.Herein,chiral molecules L/D-PF1 and L/D-PF2 with pyrene groups were synthesized and its chiroptical properties upon co-assembly with achiral compound octafluoronaphthalene(OFN) through AP interaction were systemically studied.The co-assembly of L/D-PF1/OFN and L/D-PF2/OFN exhibited distinct chiroptical properties such as circular dichroism(CD) and circularly polarized luminescence(CPL) signals.Chirality transfer from the chirality center of L/D-PF1 and L/D-PF2 to the achiral OFN and chiral amplification were successfully achieved.Besides,no significant CPL signal was observed in the self-assembly of L/DPF1 or L/D-PF2 while co-assembly with OFN exhibited obvious CPL amplification induced by AP interaction.Notably,a reversal CD signal and CPL signal could be observed in L/D-PF2/OFN when the molar ratio changed from 1:1 to 1:2 while not found in L/D-PF1/OFN,indicating that that minor structural changes of molecules could cause large changes in assembly.In addition,a series of computational calculations were conducted to verify the AP interaction between L-PF1/L-PF2 and OFN.This work demonstrated that arene-perfluoroarene interaction could drive chiral transfer,chiral amplification and chiral inversion and provided a new method for the preparation of chiroptical materials.展开更多
The widely distributed loess deposits in the Yellow River Basin exhibit unique engineering geological characteristics.The variations in their thickness and stratigraphic structure significantly amplify ground motion p...The widely distributed loess deposits in the Yellow River Basin exhibit unique engineering geological characteristics.The variations in their thickness and stratigraphic structure significantly amplify ground motion parameters,directly influencing the regional seismic hazard risk level.This study methodically conducted on-site studies and observations of building collapses and damages resulting from seismic amplification effects,using the Wenchuan M_(S)8.0 earthquake as a case study.Comprehensive experimental and numerical simulation studies were carried out.A large-scale shaking table test was performed,and numerical models for 14 different loess sites types were established.Various types of seismic waves were incorporated into these models for systematic numerical simulation calculations.The research reveals the mechanisms by which loess deposit thickness and stratigraphic structure in the Yellow River Basin affect seismic ground motion amplification.The results indicate that as the epicentral distance increases,the peak ground motion shows a marked attenuation trend,with the horizontal component attenuating substantially faster than the vertical component.As the overlying loess layer thickness increases from 50 to 100 m,the seismic intensity may escalate by 3−4 degrees,and the peak acceleration may amplify by 1.5−2.2 times.With the augmentation of loess deposit thickness and the proliferation of soil layers,both the peak acceleration response spectrum and the characteristic period demonstrate an upward tendency,exhibiting slight fluctuations contingent upon the seismic wave type.展开更多
We present a theoretical investigation of weak-value amplification(WVA)under decoherence,quantifying its metrological capabilities through the quantum Fisher information(QFI).By modeling decoherence via Kraus operator...We present a theoretical investigation of weak-value amplification(WVA)under decoherence,quantifying its metrological capabilities through the quantum Fisher information(QFI).By modeling decoherence via Kraus operators acting before and after the weak measurement interaction,we derive exact expressions for the QFI governing parameter estimation of a weak coupling strength.These analytical results reveal the fundamental limitation imposed by decoherence on the QFI achievable via WVA.From these results,the optimal post-selection state that maximizes the QFI can be derived for different noise environments.Through paradigmatic examples,including amplitude damping and depolarizing channels,we demonstrate a key distinction:the optimal post-selection evolves with the noise strength in the amplitude damping channel,but is fixed in the depolarizing channel.This work provides both theoretical insights and practical guidance for optimizing metrological schemes based on WVA in realistic decoherent environments.展开更多
With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a c...With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a convenient and visual technique with low equipment requirements and high sensitivity for the field detection of GM plants is still lacking.On the basis of the existing recombinase polymerase amplification(RPA)technique,we developed a multiplex RPA(multi-RPA)method that can simultaneously detect three transgenic elements,including the cauliflower mosaic virus 35S gene(CaMV35S)promoter,neomycin phosphotransferaseⅡgene(NptⅡ)and hygromycin B phosphotransferase gene(Hyg),thus improving the detection rate.Moreover,we coupled this multi-RPA technique with the CRISPR/Cas12a reporter system,which enabled the detection results to be clearly observed by naked eyes under ultraviolet(UV)light(254 nm;which could be achieved by a portable UV flashlight),therefore establishing a multi-RPA visual detection technique.Compared with the traditional test strip detection method,this multi-RPA-CRISPR/Cas12a technique has the higher specificity,higher sensitivity,wider application range and lower cost.Compared with other polymerase chain reaction(PCR)techniques,it also has the advantages of low equipment requirements and visualization,making it a potentially feasible method for the field detection of GM plants.展开更多
Amplification-free,highly sensitive,and specific nucleic acid detection is crucial for health monitoring and diagnosis.The type III CRISPR-Cas10 system,which provides viral immunity through CRISPRassociated protein ef...Amplification-free,highly sensitive,and specific nucleic acid detection is crucial for health monitoring and diagnosis.The type III CRISPR-Cas10 system,which provides viral immunity through CRISPRassociated protein effectors,enables a new amplification-free nucleic acid diagnostic tool.In this study,we develop a CRISPR-graphene field-effect transistors(GFETs)biosensor by combining the type III CRISPR-Cas10 system with GFETs for direct nucleic acid detection.This biosensor exploits the target RNA-activated continuous ss DNA cleavage activity of the d Csm3 CRISPR-Cas10 effector and the high charge density of a hairpin DNA reporter on the GFET channel to achieve label-free,amplification-free,highly sensitive,and specific RNA detection.The CRISPR-GFET biosensor exhibits excellent performance in detecting medium-length RNAs and miRNAs,with detection limits at the aM level and a broad linear range of 10^(-15)to 10^(-11)M for RNAs and 10^(-15)to 10^(-9)M for miRNAs.It shows high sensitivity in throat swabs and serum samples,distinguishing between healthy individuals(N=5)and breast cancer patients(N=6)without the need for extraction,purification,or amplification.This platform mitigates risks associated with nucleic acid amplification and cross-contamination,making it a versatile and scalable diagnostic tool for molecular diagnostics in human health.展开更多
Glial fibrillary acidic protein(GFAP)is one of the discriminative biomarkers for diagnosing traumatic brain injury(TBI),and accurate determination of GFAP is clinically significant.In this study,a novel fluorescence i...Glial fibrillary acidic protein(GFAP)is one of the discriminative biomarkers for diagnosing traumatic brain injury(TBI),and accurate determination of GFAP is clinically significant.In this study,a novel fluorescence immunoassay system was designed.We encapsulated carbon dots with a high fluorescence quantum yield(QY=92.5%)inside silicon nanocapsules to serve as fluorescent markers.These markers were then integrated with the streptavidin(SA)-biotin biomagnification system and immunomagnetic separation technology for the sensitive detection of GFAP.Based on the signal cascade amplification effect of the silicon nanocapsules and SA-biotin,the fluorescence signal of the SA-biotin-modified immunofluorescence nanocapsules increased 3.6-fold compared to the carbon dot-based immunoprobe.The fluorescence immunoassay system was constructed for GFAP using SA-biotin-modified immunocapsules as the sensing probe and immunomagnetic nanoparticles as the immunorecognition probe.The fluorescence immunoassay system can specifically and ultra-sensitively quantify GFAP in blood samples,with a detection range of 10 pg/mL–10 ng/mL and detection limits of 3.2 pg/mL(serum)and 3.6 pg/mL(plasma).Moreover,the fluorescence immunoassay system exhibited prominent recoveries of 99.4%–100.4%(phosphate buffered saline),96%–102.6%(serum),and 93.2%–110.2%(plasma),with favorable specificity and excellent stabilization.The novel fluorescence immunoassay system provides a new approach to the clinical analysis of GFAP and may serve as a potential tool for screening and diagnosing TBI.展开更多
Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitori...Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitoring.Nevertheless,challenges still exist in detecting ultra-low concentration analytes due to the inherent sensitivity limitations of LFIA.Recently,significant advances have been achieved by integrating enzyme activity probes and transforming LFIA into a highly sensitive tool for rapidly detecting trace analyte concentrations.Specifically,modifying natural enzymes or engineered nanozymes allows them to function as immune probes,directly catalyzing the production of signal molecules or indirectly initiating enzyme activity.Therefore,the signal intensity and detection sensitivity of LFIA are markedly elevated.The present review undertakes a comprehensive examination of pertinent research literature,offering a systematic analysis of recently proposed enzyme-based signal amplification strategies.By way of comparative assessment,the merits and demerits of current approaches are delineated,along with the identification of research avenues that still need to be explored.It is anticipated that this critical overview will garner considerable attention within the biomedical and materials science communities,providing valuable direction and insight toward the advancement of high-performance LFIA technologies.展开更多
Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,...Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,we reported a liposome-mediated signal-off photoelectrochemical(PEC)immunoassay for the sensitive detection of carcinoembryonic antigen(CEA)using ternary transition metal sulfide CuS/ZnCdS as the photoactive material.Good photocurrents were acquired on the basis of specific oxidation reaction of dopamine on the CuS/ZnCdS.The energy band relationship of CuS/ZnCdS was determined,and the wellmatched oxidation potential of dopamine was verified.To achieve accurate recovery of low-abundance CEA,systematic PEC evaluation from human serum samples was performed by combining with classical immunoreaction and liposome-induced dopamine amplification strategy with high stability and selectivity.Under optimum conditions,PEC immunoassay displayed good photocurrent responses toward target CEA with a dynamic linear range of 0.1-50 ng/mL with a detection limit of 31.6 pg/mL.Importantly,this system by combining with a discussion of energy level matching between semiconductor energy bands and small-molecules opens a new horizon for development of high-efficient PEC immunoassays.展开更多
[Objectives]To develop methods for the early and rapid detection of tomato gray mold.[Methods]Utilizing the ACTIN gene of Botrytis cinerea as the target,a set of specific primers for loop-mediated isothermal amplifica...[Objectives]To develop methods for the early and rapid detection of tomato gray mold.[Methods]Utilizing the ACTIN gene of Botrytis cinerea as the target,a set of specific primers for loop-mediated isothermal amplification(LAMP)was designed and screened.Subsequently,the reaction system and conditions were optimized to achieve rapid isothermal amplification of B.cinerea.[Results]Through agarose gel electrophoresis and SYBR GreenⅠvisualization analysis,the optimal dosages of BstⅡDNA polymerase and dNTPs,as well as the optimal ratio of internal to external primers,were determined to be 0.6 U/μL,1.25 mmol/L,and 2:1,respectively.The specific detection of B.cinerea was accomplished at 61℃ for 40 min,achieving a sensitivity of 100 ag/μL,which is 106 times greater than that of conventional PCR detection.When this method was applied to the detection of tomato diseases,the detection limit for B.cinerea spores reached 20 spores/mL.Furthermore,the pathogen was detectable in tomato leaves that had been infected for 4 d,despite the absence of visible phenotypic symptoms of gray mold.[Conclusions]This method is suitable for the early,rapid,sensitive,and visual detection of tomato gray mold,thereby offering technical support for its early diagnosis,prevention,and control.展开更多
Surface irregularities,such as hills and ridges,can significantly amplify ground motion caused by earthquakes.Therefore,in this study,we propose an analytical solution model to investigate the interaction between an a...Surface irregularities,such as hills and ridges,can significantly amplify ground motion caused by earthquakes.Therefore,in this study,we propose an analytical solution model to investigate the interaction between an asymmetric triangular hill on Earth and SH waves.Firstly,based on the development of wave functions and regional matching techniques,we introduce a semi-circular artificial auxiliary boundary,dividing the solution model into a semi-infinite body containing a semi-circular depression and an asymmetric fan-shaped region.Secondly,we derive the domain function form applicable to solving asymmetric problems.Utilizing the theory of complex variables,we establish a well-posed matrix for solving domain functions within the same coordinate system.Numerical results demonstrate that the scattering of SH waves by a protuberance is jointly influenced by the geometric parameters of the hill and the angle of incidence.Additionally,the frequency of the incident wave also has a certain degree of impact on the displacement amplitude.This study elucidates the scattering mechanism of SH waves by complex boundaries,providing a theoretical reference for building site selection and seismic design.In practical problems,the asymmetric assumption is more applicable than the symmetry assumption.展开更多
Porcine Contagious Pleuropneumonia(PCP)is a respiratory infectious disease of pigs caused by Actinobacillus pleuropneumoniae.The disease has been prevalent in pig farms since it was first identified in 1957(Pattison e...Porcine Contagious Pleuropneumonia(PCP)is a respiratory infectious disease of pigs caused by Actinobacillus pleuropneumoniae.The disease has been prevalent in pig farms since it was first identified in 1957(Pattison et al.1957).展开更多
Chemodynamic therapy(CDT),using Fenton agents to generate highly cytotoxic•OH from H_(2)O_(2)has been demonstrated as a powerful anticancer method.However,the insufficient endogenous H_(2)O_(2)in tumor cells greatly l...Chemodynamic therapy(CDT),using Fenton agents to generate highly cytotoxic•OH from H_(2)O_(2)has been demonstrated as a powerful anticancer method.However,the insufficient endogenous H_(2)O_(2)in tumor cells greatly limited its therapeutic effect.Herein,we prepared a pH-responsiveβ-lapachone-loaded ironpolyphenol nanocomplex(LIPN)through a one-pot method.β-Lapachone in LIPN selectively enhanced H_(2)O_(2)concentration in tumor cells,and ferrous ions cascadely generated abundant cytotoxic•OH.Therefore,LIPN with cascade amplification of reactive oxygen species(ROS)showed high chemodynamic cytotoxicity in tumor cells,efficiently improving the expression of damage-associated molecular patterns(DAMPs),and exerting strong immunogenic cell death(ICD).As a result,LIPN exhibited efficient tumor inhibition ability in 4T1 subcutaneous tumor model in vivo with great biocompatibility.Additionally,the infiltration of cytotoxic CD8^(+)T lymphocytes and inhibition of regulatory CD4^(+)FoxP3^(+)T lymphocytes in tumors demonstrated the activation of immunosuppressive tumor microenvironment by LIPN-induced ICD.Therefore,this work provided a new approach to enhance ICD of chemodynamic therapy through selective cascade amplification of ROS in cancer cells.展开更多
Although diverse signal-amplified methods have been committed to improve the sensitivity of surface plasmon resonance(SPR)biosensing,introducing convenient and robust signal amplification strategy into SPR biosensing ...Although diverse signal-amplified methods have been committed to improve the sensitivity of surface plasmon resonance(SPR)biosensing,introducing convenient and robust signal amplification strategy into SPR biosensing remains challenging.Here,a novel nanozyme-triggered polymerization amplification strategy was proposed for constructing highly sensitive surface plasmon resonance(SPR)immunosensor.In detail,Au@Pd core-shell nanooctahedra nanozyme with superior peroxidase(POD)-like activity was synthesized and utilized as a label probe.Simultaneously,Au@Pd core-shell nanooctahedra nanozyme can catalyze the decomposition of H_(2)O_(2)to form hydroxyl radicals(·OH)that triggers the polymerization of aniline to form polyaniline attaching on the surface of sensor chip,significantly amplifying SPR responses.The sensitivity of SPR immunosensor was enhanced by nanozyme-triggered polymerization amplification strategy.Using human immunoglobulin G(HIgG)as a model,the constructed SPR immunosensor obtains a wide linear range of 0.005–1.0μg/m L with low detection limit of 0.106 ng/m L.This research provides new sights on establishing sensitive SPR immunosensor and may evokes more inspiration for developing signal amplification methods based on nanozyme in biosensing.展开更多
Bacterial blight(BB) is a devastating worldwide rice disease caused by Xanthomonas oryzae pv. oryzae(Xoo), which is difficult to diagnose based on early symptoms. Conventional chemical control yields limited effective...Bacterial blight(BB) is a devastating worldwide rice disease caused by Xanthomonas oryzae pv. oryzae(Xoo), which is difficult to diagnose based on early symptoms. Conventional chemical control yields limited effectiveness once BB has spread. Consequently, it is imperative to develop a rapid, highly sensitive, specific, and easy-to-use detection technique for early on-site diagnosis of BB. We first developed a recombinase-aided amplification-lateral flow dipstick(RAA-LFD) technique for the on-site detection of Xoo. The optimized reaction temperature and time were 37 ℃ and 20 min, indicating that the reaction system can be initiated by body temperature independently of any precision instruments. Evaluation of the RAA-LFD technique using the primers(RAAF2/R2) and probe(RAA2-nfo-probe) derived from the Xoo ORF0080 locus exhibited high specificity and eliminated cross-reactivity with other bacterial species. The sensitivity of RAA-LFD is up to 1 pg/μL for Xoo genomic DNA and 100 CFU/m L for Xoo cells. Significantly, this technique accurately detected Xoo from both artificially inoculated and naturally infected rice leaves at the early stage of infection, directly deploying plant tissue fluid as the template without DNA extraction. These attributes make the developed RAA-LFD system a viable technique for the early diagnosis of BB in the field, providing technical support for early-warning systems and disease control.展开更多
To capture the nonlinear dynamics and gain evolution in chirped pulse amplification(CPA)systems,the split-step Fourier method and the fourth-order Runge–Kutta method are integrated to iteratively address the generali...To capture the nonlinear dynamics and gain evolution in chirped pulse amplification(CPA)systems,the split-step Fourier method and the fourth-order Runge–Kutta method are integrated to iteratively address the generalized nonlinear Schrödinger equation and the rate equations.However,this approach is burdened by substantial computational demands,resulting in significant time expenditures.In the context of intelligent laser optimization and inverse design,the necessity for numerous simulations further exacerbates this issue,highlighting the need for fast and accurate simulation methodologies.Here,we introduce an end-to-end model augmented with active learning(E2E-AL)with decent generalization through different dedicated embedding methods over various parameters.On an identical computational platform,the artificial intelligence–driven model is 2000 times faster than the conventional simulation method.Benefiting from the active learning strategy,the E2E-AL model achieves decent precision with only two-thirds of the training samples compared with the case without such a strategy.Furthermore,we demonstrate a multi-objective inverse design of the CPA systems enabled by the E2E-AL model.The E2E-AL framework manifests the potential of becoming a standard approach for the rapid and accurate modeling of ultrafast lasers and is readily extended to simulate other complex systems.展开更多
DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide ...DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide convincing evidence based on the comparison of the activity of multiple enzymes than on that of single enzyme.Although fluorescence approach has been applied for the simultaneous detection both of DNA repair enzymes,the spectral overlap and multiwavelength excitation severely restrict the number of available fluorophores.Thus,it is difficult to simultaneously detect three enzymes in a single analysis by fluorescence detection.Herein,we developed a method for the simultaneous determination of three DNA repair enzymes including human flap DNA endonuclease 1(FEN1),human alkyladenine DNA glycosylase(hAAG)and uracil DNA glycosylase(UDG)based on the combination of template-free amplification system with capillary electrophoresis-laser induced fluorescence(CE-LIF)detection.The amplification system was adopted to transfer and amplify the enzymatic products into different length DNA fragments which could be separated effectively by CE-LIF without the complicated modification of the capillary inner wall or labeling different tails on signal probes for separation.The method demonstrated a detection limit of 0.07 U/mL(0.08-160 U/mL)for FEN1,2.40 U/mL(2.5-250U/mL)for hAAG and 2.1×10^(-4)U/mL(0.0004-2.5 U/mL)for UDG,the relative standard deviations(RSDs)of peak time and peak area for different analytes were as follows:2.50%-4,37%and 3.24%-7.18%(inter-day);1.37%-2.71%and 1.43%-3.02%(intra-day),4.28%-6.08%and 4.16%-7.57%(column to column),respectively.And it can identify the inhibitor-like drugs,evaluate enzymatic kinetics and achieve the detection of three enzymes in cell extracts,providing a simple and powerful platform for simultaneous detection of more DNA repair enzymes.展开更多
基金supported partially by the Australian Government through the Australian Research Council Centres of Excellence funding scheme(project CE200100029)。
文摘Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we developed a bacterial type-II toxin-antitoxin-mediated method to manipulate genomic integration of tandem gene repeats in Saccharomyces cerevisiae and further visualised the evolutionary trajectories of gene repeats.We designed a tri-vector system to introduce toxin-antitoxin-driven gene amplification modules.Results:This system delivered multi-copy gene integration in the form of tandem gene repeats spontaneously and independently from toxin-antitoxin-mediated selection.Inducing the toxin(RelE)expressing via a copper(II)-inducible CUP1 promoter successfully drove the in-situ gene amplification of the antitoxin(RelB)module,resulting in~40 copies of a green fluorescence reporter gene per copy of genome.Copy-number changes,copy-number increase and copy-number decrease,and stable maintenance were visualised using the green fluorescence protein and blue chromoprotein AeBlue as reporters.Copy-number increases happened spontaneously and independent on a selection pressure.Increased copy number was quickly enriched through toxin-antitoxin-mediated selection.Conclusion:In summary,the bacterial toxin-antitoxin systems provide a flexible mechanism to manipulate gene copy number in eukaryotic cells and can be exploited for synthetic biology and metabolic engineering applications.
基金Natural Science Foundation of Hebei Province under Grant No.E2025201025,the Science Research Project of Hebei Education Department under Grant No.BJK2024121the Open Fund of Hebei Cangzhou Groundwater and Land Subsidence National Observation and Research Station under Grant No.CGLOS-2025-04+1 种基金the HBU Innovation Team for Multi-Disaster Prevention in Transportation Geotechnics under Grant No.IT2023C04the Research Fund for Talented Scholars of HBU under Grant No.521100221063。
文摘Tire-derived aggregate(TDA)is an engineered construction material produced from recycled scrap tires and is often used as a compressible layer overlying buried structures to reduce overburden loads.The potential amplification of ground motion in a tunnel site is well understood,but the effect of the tunnel-TDA layer system on ground surface acceleration remains unclear.In this study,both linear and nonlinear dynamic analyses were performed to evaluate the contributions of a TDA layer to the acceleration amplification at the ground surface.The numerical model was calibrated using recorded data from a shaking table test and validated against the literature results,followed by extensive parametric studies.The mechanical and geometrical parameters investigated for the TDA layer included damping ratio,density,Young’s modulus,width,thickness,and depth.The predominant frequency and intensity level of input motions were also investigated.This study showed that the presence of the TDA layer provided an additional acceleration amplification effect.The amplification was more pronounced in areas above the tunnel,particularly for the wider and shallower TDA layer subjected to high frequency and low intensity input motions.
基金financially supported by the National Natural Science Foundation of China (Nos.22171165 and 22371170)Natural Science Foundation of Shandong Province (No.ZR2022MB080)Scientific and Technological Frontiers in Project of Henan Province(No.242102110192)。
文摘Co-assembling chiral molecules with achiral compounds via non-covalent interactions like areneperfluoroarene(AP) interactions offers an effective approach for fabricating chiral functional materials.Herein,chiral molecules L/D-PF1 and L/D-PF2 with pyrene groups were synthesized and its chiroptical properties upon co-assembly with achiral compound octafluoronaphthalene(OFN) through AP interaction were systemically studied.The co-assembly of L/D-PF1/OFN and L/D-PF2/OFN exhibited distinct chiroptical properties such as circular dichroism(CD) and circularly polarized luminescence(CPL) signals.Chirality transfer from the chirality center of L/D-PF1 and L/D-PF2 to the achiral OFN and chiral amplification were successfully achieved.Besides,no significant CPL signal was observed in the self-assembly of L/DPF1 or L/D-PF2 while co-assembly with OFN exhibited obvious CPL amplification induced by AP interaction.Notably,a reversal CD signal and CPL signal could be observed in L/D-PF2/OFN when the molar ratio changed from 1:1 to 1:2 while not found in L/D-PF1/OFN,indicating that that minor structural changes of molecules could cause large changes in assembly.In addition,a series of computational calculations were conducted to verify the AP interaction between L-PF1/L-PF2 and OFN.This work demonstrated that arene-perfluoroarene interaction could drive chiral transfer,chiral amplification and chiral inversion and provided a new method for the preparation of chiroptical materials.
基金supported by the Earthquake Science and Technology Spark Plan Project(No.XH23041C)The Natural Science Foundation of Gansu Province(No.22JR11RA090)Gansu Lanzhou Geophysics National Observation and Research Station(No.2021Y14).
文摘The widely distributed loess deposits in the Yellow River Basin exhibit unique engineering geological characteristics.The variations in their thickness and stratigraphic structure significantly amplify ground motion parameters,directly influencing the regional seismic hazard risk level.This study methodically conducted on-site studies and observations of building collapses and damages resulting from seismic amplification effects,using the Wenchuan M_(S)8.0 earthquake as a case study.Comprehensive experimental and numerical simulation studies were carried out.A large-scale shaking table test was performed,and numerical models for 14 different loess sites types were established.Various types of seismic waves were incorporated into these models for systematic numerical simulation calculations.The research reveals the mechanisms by which loess deposit thickness and stratigraphic structure in the Yellow River Basin affect seismic ground motion amplification.The results indicate that as the epicentral distance increases,the peak ground motion shows a marked attenuation trend,with the horizontal component attenuating substantially faster than the vertical component.As the overlying loess layer thickness increases from 50 to 100 m,the seismic intensity may escalate by 3−4 degrees,and the peak acceleration may amplify by 1.5−2.2 times.With the augmentation of loess deposit thickness and the proliferation of soil layers,both the peak acceleration response spectrum and the characteristic period demonstrate an upward tendency,exhibiting slight fluctuations contingent upon the seismic wave type.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12175052 and 12405010)Hangzhou Joint Fund of the Zhejiang Provincial Natural Science Foundation of China(Grant No.LHZSD24A050001)+4 种基金the Hangzhou Leading Youth Innovation and Entrepreneurship Team Project(Grant No.TD2024005)the HZNU scientific Research and Innovation Team Project(Grant No.TD2025003)the Guizhou Province Higher Education Teaching Content and Curriculum System Reform Project(Grant No.2023233)the Guizhou Education Department Young Talent in Science and Technology Program(Grant Nos.QianJiaoJi[2024]174 and QianJiaoJi[2024]178)Guizhou Provincial Theoretical Innovation Project(Grant No.GZLCLH-2025-ZX)。
文摘We present a theoretical investigation of weak-value amplification(WVA)under decoherence,quantifying its metrological capabilities through the quantum Fisher information(QFI).By modeling decoherence via Kraus operators acting before and after the weak measurement interaction,we derive exact expressions for the QFI governing parameter estimation of a weak coupling strength.These analytical results reveal the fundamental limitation imposed by decoherence on the QFI achievable via WVA.From these results,the optimal post-selection state that maximizes the QFI can be derived for different noise environments.Through paradigmatic examples,including amplitude damping and depolarizing channels,we demonstrate a key distinction:the optimal post-selection evolves with the noise strength in the amplitude damping channel,but is fixed in the depolarizing channel.This work provides both theoretical insights and practical guidance for optimizing metrological schemes based on WVA in realistic decoherent environments.
基金the Experimental Technology Research Project of Zhejiang University(SYB202138)National Natural Science Foundation of China(32000195)。
文摘With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a convenient and visual technique with low equipment requirements and high sensitivity for the field detection of GM plants is still lacking.On the basis of the existing recombinase polymerase amplification(RPA)technique,we developed a multiplex RPA(multi-RPA)method that can simultaneously detect three transgenic elements,including the cauliflower mosaic virus 35S gene(CaMV35S)promoter,neomycin phosphotransferaseⅡgene(NptⅡ)and hygromycin B phosphotransferase gene(Hyg),thus improving the detection rate.Moreover,we coupled this multi-RPA technique with the CRISPR/Cas12a reporter system,which enabled the detection results to be clearly observed by naked eyes under ultraviolet(UV)light(254 nm;which could be achieved by a portable UV flashlight),therefore establishing a multi-RPA visual detection technique.Compared with the traditional test strip detection method,this multi-RPA-CRISPR/Cas12a technique has the higher specificity,higher sensitivity,wider application range and lower cost.Compared with other polymerase chain reaction(PCR)techniques,it also has the advantages of low equipment requirements and visualization,making it a potentially feasible method for the field detection of GM plants.
基金financially supported by the National Science and Technology Innovation 2030 Grants(2021ZD0201600)the National Key R&D Program of China(2021YFA0717000)+2 种基金the Intramural Joint Program Fund of State Key Laboratory of Microbial Technology(Project No.SKLMTIJP-2024-05)the Natural Science Foundation of Qingdao-Original exploration project(Project No.24-4-4-zrjj-139-jch)the National Natural Science Foundation of China(31771380)。
文摘Amplification-free,highly sensitive,and specific nucleic acid detection is crucial for health monitoring and diagnosis.The type III CRISPR-Cas10 system,which provides viral immunity through CRISPRassociated protein effectors,enables a new amplification-free nucleic acid diagnostic tool.In this study,we develop a CRISPR-graphene field-effect transistors(GFETs)biosensor by combining the type III CRISPR-Cas10 system with GFETs for direct nucleic acid detection.This biosensor exploits the target RNA-activated continuous ss DNA cleavage activity of the d Csm3 CRISPR-Cas10 effector and the high charge density of a hairpin DNA reporter on the GFET channel to achieve label-free,amplification-free,highly sensitive,and specific RNA detection.The CRISPR-GFET biosensor exhibits excellent performance in detecting medium-length RNAs and miRNAs,with detection limits at the aM level and a broad linear range of 10^(-15)to 10^(-11)M for RNAs and 10^(-15)to 10^(-9)M for miRNAs.It shows high sensitivity in throat swabs and serum samples,distinguishing between healthy individuals(N=5)and breast cancer patients(N=6)without the need for extraction,purification,or amplification.This platform mitigates risks associated with nucleic acid amplification and cross-contamination,making it a versatile and scalable diagnostic tool for molecular diagnostics in human health.
基金supported by the AMS Funding Project(No.ZZB2023C7010).
文摘Glial fibrillary acidic protein(GFAP)is one of the discriminative biomarkers for diagnosing traumatic brain injury(TBI),and accurate determination of GFAP is clinically significant.In this study,a novel fluorescence immunoassay system was designed.We encapsulated carbon dots with a high fluorescence quantum yield(QY=92.5%)inside silicon nanocapsules to serve as fluorescent markers.These markers were then integrated with the streptavidin(SA)-biotin biomagnification system and immunomagnetic separation technology for the sensitive detection of GFAP.Based on the signal cascade amplification effect of the silicon nanocapsules and SA-biotin,the fluorescence signal of the SA-biotin-modified immunofluorescence nanocapsules increased 3.6-fold compared to the carbon dot-based immunoprobe.The fluorescence immunoassay system was constructed for GFAP using SA-biotin-modified immunocapsules as the sensing probe and immunomagnetic nanoparticles as the immunorecognition probe.The fluorescence immunoassay system can specifically and ultra-sensitively quantify GFAP in blood samples,with a detection range of 10 pg/mL–10 ng/mL and detection limits of 3.2 pg/mL(serum)and 3.6 pg/mL(plasma).Moreover,the fluorescence immunoassay system exhibited prominent recoveries of 99.4%–100.4%(phosphate buffered saline),96%–102.6%(serum),and 93.2%–110.2%(plasma),with favorable specificity and excellent stabilization.The novel fluorescence immunoassay system provides a new approach to the clinical analysis of GFAP and may serve as a potential tool for screening and diagnosing TBI.
基金Financial supports from the National Natural Science Foundation of China(NSFC,Nos.52272144 and 22205048)Heilongjiang Provincial Natural Science Foundation of China(No.JQ2022E001)+3 种基金China Postdoctoral Science Foundation(Nos.2022M710931 and 2023T160154)Heilongjiang Postdoctoral Science Foundation(No.LBH-Z22010)Natural Science Foundation of Shandong Province(No.ZR2020ZD42)the Fundamental Research funds for the Central Universities are greatly acknowledged.
文摘Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitoring.Nevertheless,challenges still exist in detecting ultra-low concentration analytes due to the inherent sensitivity limitations of LFIA.Recently,significant advances have been achieved by integrating enzyme activity probes and transforming LFIA into a highly sensitive tool for rapidly detecting trace analyte concentrations.Specifically,modifying natural enzymes or engineered nanozymes allows them to function as immune probes,directly catalyzing the production of signal molecules or indirectly initiating enzyme activity.Therefore,the signal intensity and detection sensitivity of LFIA are markedly elevated.The present review undertakes a comprehensive examination of pertinent research literature,offering a systematic analysis of recently proposed enzyme-based signal amplification strategies.By way of comparative assessment,the merits and demerits of current approaches are delineated,along with the identification of research avenues that still need to be explored.It is anticipated that this critical overview will garner considerable attention within the biomedical and materials science communities,providing valuable direction and insight toward the advancement of high-performance LFIA technologies.
基金financial support from the National Natural Science Foundation of China(Nos.22274022 and 21874022).
文摘Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,we reported a liposome-mediated signal-off photoelectrochemical(PEC)immunoassay for the sensitive detection of carcinoembryonic antigen(CEA)using ternary transition metal sulfide CuS/ZnCdS as the photoactive material.Good photocurrents were acquired on the basis of specific oxidation reaction of dopamine on the CuS/ZnCdS.The energy band relationship of CuS/ZnCdS was determined,and the wellmatched oxidation potential of dopamine was verified.To achieve accurate recovery of low-abundance CEA,systematic PEC evaluation from human serum samples was performed by combining with classical immunoreaction and liposome-induced dopamine amplification strategy with high stability and selectivity.Under optimum conditions,PEC immunoassay displayed good photocurrent responses toward target CEA with a dynamic linear range of 0.1-50 ng/mL with a detection limit of 31.6 pg/mL.Importantly,this system by combining with a discussion of energy level matching between semiconductor energy bands and small-molecules opens a new horizon for development of high-efficient PEC immunoassays.
基金Supported by Central Guiding Local Science and Technology Development Fund Project of Hebei Province(226Z6501G)Science and Technology Program of Hebei Academy of Sciences(23306,24306,25306).
文摘[Objectives]To develop methods for the early and rapid detection of tomato gray mold.[Methods]Utilizing the ACTIN gene of Botrytis cinerea as the target,a set of specific primers for loop-mediated isothermal amplification(LAMP)was designed and screened.Subsequently,the reaction system and conditions were optimized to achieve rapid isothermal amplification of B.cinerea.[Results]Through agarose gel electrophoresis and SYBR GreenⅠvisualization analysis,the optimal dosages of BstⅡDNA polymerase and dNTPs,as well as the optimal ratio of internal to external primers,were determined to be 0.6 U/μL,1.25 mmol/L,and 2:1,respectively.The specific detection of B.cinerea was accomplished at 61℃ for 40 min,achieving a sensitivity of 100 ag/μL,which is 106 times greater than that of conventional PCR detection.When this method was applied to the detection of tomato diseases,the detection limit for B.cinerea spores reached 20 spores/mL.Furthermore,the pathogen was detectable in tomato leaves that had been infected for 4 d,despite the absence of visible phenotypic symptoms of gray mold.[Conclusions]This method is suitable for the early,rapid,sensitive,and visual detection of tomato gray mold,thereby offering technical support for its early diagnosis,prevention,and control.
基金supported by the National Key R&D Program of China(Grant No.2022YFC3003601)Joint Funds of the National Natural Science Foundation of China Project on Earthquake Science(Grant No.U2239252)the program of the Innovative Research Team in China Earthquake Administration.
文摘Surface irregularities,such as hills and ridges,can significantly amplify ground motion caused by earthquakes.Therefore,in this study,we propose an analytical solution model to investigate the interaction between an asymmetric triangular hill on Earth and SH waves.Firstly,based on the development of wave functions and regional matching techniques,we introduce a semi-circular artificial auxiliary boundary,dividing the solution model into a semi-infinite body containing a semi-circular depression and an asymmetric fan-shaped region.Secondly,we derive the domain function form applicable to solving asymmetric problems.Utilizing the theory of complex variables,we establish a well-posed matrix for solving domain functions within the same coordinate system.Numerical results demonstrate that the scattering of SH waves by a protuberance is jointly influenced by the geometric parameters of the hill and the angle of incidence.Additionally,the frequency of the incident wave also has a certain degree of impact on the displacement amplitude.This study elucidates the scattering mechanism of SH waves by complex boundaries,providing a theoretical reference for building site selection and seismic design.In practical problems,the asymmetric assumption is more applicable than the symmetry assumption.
基金supported by the University-Industry Col aborative Education Program,China(220904860093831)。
文摘Porcine Contagious Pleuropneumonia(PCP)is a respiratory infectious disease of pigs caused by Actinobacillus pleuropneumoniae.The disease has been prevalent in pig farms since it was first identified in 1957(Pattison et al.1957).
基金supported by the National Natural Science Foundation of China(Nos.T2293753,52203194)the National Key R&D Program of China(No.2021YFA1201200)+1 种基金the Natural Science Foundation of Zhejiang Province(No.LR18E030002)2023 Hangzhou West Lake Pearl Project Leading Innovative Youth Team Project.
文摘Chemodynamic therapy(CDT),using Fenton agents to generate highly cytotoxic•OH from H_(2)O_(2)has been demonstrated as a powerful anticancer method.However,the insufficient endogenous H_(2)O_(2)in tumor cells greatly limited its therapeutic effect.Herein,we prepared a pH-responsiveβ-lapachone-loaded ironpolyphenol nanocomplex(LIPN)through a one-pot method.β-Lapachone in LIPN selectively enhanced H_(2)O_(2)concentration in tumor cells,and ferrous ions cascadely generated abundant cytotoxic•OH.Therefore,LIPN with cascade amplification of reactive oxygen species(ROS)showed high chemodynamic cytotoxicity in tumor cells,efficiently improving the expression of damage-associated molecular patterns(DAMPs),and exerting strong immunogenic cell death(ICD).As a result,LIPN exhibited efficient tumor inhibition ability in 4T1 subcutaneous tumor model in vivo with great biocompatibility.Additionally,the infiltration of cytotoxic CD8^(+)T lymphocytes and inhibition of regulatory CD4^(+)FoxP3^(+)T lymphocytes in tumors demonstrated the activation of immunosuppressive tumor microenvironment by LIPN-induced ICD.Therefore,this work provided a new approach to enhance ICD of chemodynamic therapy through selective cascade amplification of ROS in cancer cells.
基金supported by National Natural Science Foundation of China(Nos.22474124,21575125)the National Natural Science Foundation of Jiangsu Province(No.BK20221370)+4 种基金Key University Natural Science Foundation of Jiangsu-Province(No.20KJA150004)the Project for Science and Technology of Yangzhou(No.YZ2022074)Project for Yangzhou City and Yangzhou University corporation(No.YZ2023204)the Open Research Fund of State Key Laboratory of Analytical Chemistry for Life Science(No.SKLACLS2405)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_3462)。
文摘Although diverse signal-amplified methods have been committed to improve the sensitivity of surface plasmon resonance(SPR)biosensing,introducing convenient and robust signal amplification strategy into SPR biosensing remains challenging.Here,a novel nanozyme-triggered polymerization amplification strategy was proposed for constructing highly sensitive surface plasmon resonance(SPR)immunosensor.In detail,Au@Pd core-shell nanooctahedra nanozyme with superior peroxidase(POD)-like activity was synthesized and utilized as a label probe.Simultaneously,Au@Pd core-shell nanooctahedra nanozyme can catalyze the decomposition of H_(2)O_(2)to form hydroxyl radicals(·OH)that triggers the polymerization of aniline to form polyaniline attaching on the surface of sensor chip,significantly amplifying SPR responses.The sensitivity of SPR immunosensor was enhanced by nanozyme-triggered polymerization amplification strategy.Using human immunoglobulin G(HIgG)as a model,the constructed SPR immunosensor obtains a wide linear range of 0.005–1.0μg/m L with low detection limit of 0.106 ng/m L.This research provides new sights on establishing sensitive SPR immunosensor and may evokes more inspiration for developing signal amplification methods based on nanozyme in biosensing.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LY23C130004 and LZ24C130004)the National Natural Science Foundation of China(Grant No.32472115)+1 种基金the National Key Research and Development Program of China(Grant No.2022YFF1003301)the Agricultural Sciences and Technologies Innovation Program of Chinese Academy of Agricultural Sciences。
文摘Bacterial blight(BB) is a devastating worldwide rice disease caused by Xanthomonas oryzae pv. oryzae(Xoo), which is difficult to diagnose based on early symptoms. Conventional chemical control yields limited effectiveness once BB has spread. Consequently, it is imperative to develop a rapid, highly sensitive, specific, and easy-to-use detection technique for early on-site diagnosis of BB. We first developed a recombinase-aided amplification-lateral flow dipstick(RAA-LFD) technique for the on-site detection of Xoo. The optimized reaction temperature and time were 37 ℃ and 20 min, indicating that the reaction system can be initiated by body temperature independently of any precision instruments. Evaluation of the RAA-LFD technique using the primers(RAAF2/R2) and probe(RAA2-nfo-probe) derived from the Xoo ORF0080 locus exhibited high specificity and eliminated cross-reactivity with other bacterial species. The sensitivity of RAA-LFD is up to 1 pg/μL for Xoo genomic DNA and 100 CFU/m L for Xoo cells. Significantly, this technique accurately detected Xoo from both artificially inoculated and naturally infected rice leaves at the early stage of infection, directly deploying plant tissue fluid as the template without DNA extraction. These attributes make the developed RAA-LFD system a viable technique for the early diagnosis of BB in the field, providing technical support for early-warning systems and disease control.
基金supported by the National Natural Science Foundation of China(Grant Nos.62227821,62025503,and 62205199).
文摘To capture the nonlinear dynamics and gain evolution in chirped pulse amplification(CPA)systems,the split-step Fourier method and the fourth-order Runge–Kutta method are integrated to iteratively address the generalized nonlinear Schrödinger equation and the rate equations.However,this approach is burdened by substantial computational demands,resulting in significant time expenditures.In the context of intelligent laser optimization and inverse design,the necessity for numerous simulations further exacerbates this issue,highlighting the need for fast and accurate simulation methodologies.Here,we introduce an end-to-end model augmented with active learning(E2E-AL)with decent generalization through different dedicated embedding methods over various parameters.On an identical computational platform,the artificial intelligence–driven model is 2000 times faster than the conventional simulation method.Benefiting from the active learning strategy,the E2E-AL model achieves decent precision with only two-thirds of the training samples compared with the case without such a strategy.Furthermore,we demonstrate a multi-objective inverse design of the CPA systems enabled by the E2E-AL model.The E2E-AL framework manifests the potential of becoming a standard approach for the rapid and accurate modeling of ultrafast lasers and is readily extended to simulate other complex systems.
基金supported by the National Natural Science Foundation of China(Nos.21874060 and 22174058,U21A20282)the Science and Technology program of Gansu Province(No.22JR5RA476)。
文摘DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide convincing evidence based on the comparison of the activity of multiple enzymes than on that of single enzyme.Although fluorescence approach has been applied for the simultaneous detection both of DNA repair enzymes,the spectral overlap and multiwavelength excitation severely restrict the number of available fluorophores.Thus,it is difficult to simultaneously detect three enzymes in a single analysis by fluorescence detection.Herein,we developed a method for the simultaneous determination of three DNA repair enzymes including human flap DNA endonuclease 1(FEN1),human alkyladenine DNA glycosylase(hAAG)and uracil DNA glycosylase(UDG)based on the combination of template-free amplification system with capillary electrophoresis-laser induced fluorescence(CE-LIF)detection.The amplification system was adopted to transfer and amplify the enzymatic products into different length DNA fragments which could be separated effectively by CE-LIF without the complicated modification of the capillary inner wall or labeling different tails on signal probes for separation.The method demonstrated a detection limit of 0.07 U/mL(0.08-160 U/mL)for FEN1,2.40 U/mL(2.5-250U/mL)for hAAG and 2.1×10^(-4)U/mL(0.0004-2.5 U/mL)for UDG,the relative standard deviations(RSDs)of peak time and peak area for different analytes were as follows:2.50%-4,37%and 3.24%-7.18%(inter-day);1.37%-2.71%and 1.43%-3.02%(intra-day),4.28%-6.08%and 4.16%-7.57%(column to column),respectively.And it can identify the inhibitor-like drugs,evaluate enzymatic kinetics and achieve the detection of three enzymes in cell extracts,providing a simple and powerful platform for simultaneous detection of more DNA repair enzymes.
