Efficacy of Juanbi capsule on ameliorating knee osteoarthritis:a network pharmacology and experimental verification-based study

Background:The purpose of the study was to investigate the active ingredients and potential biochemical mechanisms of Juanbi capsule in knee osteoarthritis based on network pharmacology,molecular docking and animal experiments.Methods:Chemical components for each drug in the Juanbi capsule were obtained from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform,while the target proteins for knee osteoarthritis were retrieved from the Drugbank,GeneCards,and OMIM databases.The study compared information on knee osteoarthritis and the targets of drugs to identify common elements.The data was imported into the STRING platform to generate a protein-protein interaction network diagram.Subsequently,a“component-target”network diagram was created using the screened drug components and target information with Cytoscape software.Common targets were imported into Metascape for GO function and KEGG pathway enrichment analysis.AutoDockTools was utilized to predict the molecular docking of the primary chemical components and core targets.Ultimately,the key targets were validated through animal experiments.Results:Juanbi capsule ameliorated Knee osteoarthritis mainly by affecting tumor necrosis factor,interleukin1β,MMP9,PTGS2,VEGFA,TP53,and other cytokines through quercetin,kaempferol,andβ-sitosterol.The drug also influenced the AGE-RAGE,interleukin-17,tumor necrosis factor,Relaxin,and NF-κB signaling pathways.The network pharmacology analysis results were further validated in animal experiments.The results indicated that Juanbi capsule could decrease the levels of tumor necrosis factor-αand interleukin-1βin the serum and synovial fluid of knee osteoarthritis rats and also down-regulate the expression levels of MMP9 and PTGS2 proteins in the articular cartilage.Conclusion:Juanbi capsule may improve the knee bone microstructure and reduce the expression of inflammatory factors of knee osteoarthritis via multiple targets and multiple signaling pathways.

Numerical simulation and experimental verification of plasma jet development in gas gap switch

Plasma jet triggered gas gap switch has obvious advantages in fast control switch.The development of the plasma in the ambient medium is the key factor affecting the triggering conduction of the gas switch.However,the plasma jet process and its characteristic parameters are complicated and the existing test methods cannot fully characterize its development laws.In this work,a two-dimensional transient fluid calculation model of the plasma jet process of the gas gap switch is established based on the renormalization-group k-εturbulence equation.The results show that the characteristic parameters and morphological evolution of the plasma jet are basically consistent with the experimental results,which verifies the accuracy of the simulation model calculation.The plasma jet is a long strip with an initial velocity of 1.0 km·s-1and develops in both axial and radial directions.The jet velocity fluctuates significantly with axial height.As the plasma jet enters the main gap,the pressure inside the trigger cavity drops by80%,resulting in a rapid drop in the jet velocity.When the plasma jet head interacts with the atmosphere,the two-phase fluid compresses each other,generating a forward-propelled pressure wave.The plasma jet heads flow at high velocity,a negative pressure zone is formed in the middle part of the jet,and the pressure peak decreases gradually with height.As the value of the inlet pressure increases,the characteristic parameters of the plasma jet increase.The entrainment phenomenon is evident,which leads to an increase in the pressure imbalance of the atmospheric gas medium,leading to a significant Coanda effect.Compared with air,the characteristic parameters of a plasma jet in SF6are lower,and the morphological evolution is significantly suppressed.The results of this study can provide some insight into the mechanism of action of the switch jet plasma development process.

Molecular Mechanism of Ginseng in Treating Nephrotic Syndrome Based on Network Pharmacology and Experimental Verification

[Objectives]To study the potential molecular mechanism of ginseng in treating nephrotic syndrome(NS)by using network pharmacology,molecular docking and experimental verification methods.[Methods]The active components and targets of ginseng were obtained through the network pharmacology database,and the potential targets for the treatment of NS were predicted.The STRING data platform and Cytoscape software were used to construct protein interaction network,and carry out GO and KEGG enrichment analysis.Molecular docking of active components of ginseng and core targets was performed.The in vitro experiment verified the improvement effect of kaempferol,a key active ingredient of ginseng,on podocyte injury.[Results]After screening,17 active components of ginseng and 38 key targets for treating NS were obtained.GO and KEGG enrichment analysis showed that NF-κB,MAPK and other inflammatory pathways were involved.Molecular docking results show that the core components had good binding activity to key targets.The results of in vitro experiments show that kaempferol can reduce the phosphorylation level of AKT1,down-regulate the expression levels of NF-κB p65 and p-NF-κB p65,play an anti-inflammatory effect by inhibiting the activation of NF-κB pathway,and improve podocyte injury.[Conclusions]Ginseng may play a role in the treatment of NS by regulating multiple targets and pathways such as inflammatory response,substance metabolism,and signal transduction.

Finite Element Simulation of Flexible Roll Forming with Supplemented Material Data and the Experimental Verification

Flexible roll forming is a promising manufacturing method for the production of variable cross section products. Considering the large plastic strain in this forming process which is much larger than that of uniform deformation phase of uniaxial tensile test, the widely adopted method of simulating the forming processes with non-supplemented material data from uniaxial tensile test will certainly lead to large error. To reduce this error, the material data is supplemented based on three constitutive models. Then a finite element model of a six passes flexible roll forming process is established based on the supplemented material data and the original material data from the uniaxial tensile test. The flexible roll forming experiment of a B pillar reinforcing plate is carried out to verify the proposed method. Final cross section shapes of the experimental and the simulated results are compared. It is shown that the simulation calculated with supplemented material data based on Swift model agrees well with the experimental results, while the simulation based on original material data could not predict the actual deformation accurately. The results indicate that this material supplement method is reliable and indispensible, and the simulation model can well reflect the real metal forming process. Detailed analysis of the distribution and history of plastic strain at different positions are performed. A new material data supplement method is proposed to tackle the problem which is ignored in other roll forming simulations, and thus the forming process simulation accuracy can be greatly improved.

Optimal Design and Experimental Verification of Low Radiation Noise of Gearbox

Reducing the radiated noise of a gearbox is a difficult problem in aviation,navigation,machinery,and other fields.Structural improvement is the main means of noise reduction for a gearbox,and it is realized primarily through contribution analysis and structure optimization.However,these approaches have certain limitations.In this study,a low-noise design method for a gearbox that combines the two approaches is proposed,and experimental verification is performed.First,a finite element/boundary element model is established using a single-stage herringbone gearbox.Considering the vibration excitation of the gear system,the radiation noise of a single-stage gearbox is predicted based on the modal acoustic transfer vector(MATV)method.Subsequently,the maximum field point of the radiated noise is determined,and the acoustic transfer vector(ATV)analysis and modal acoustic contribution(MAC)analysis are conducted to determine the region that contributes significantly to the radiated noise of the field point.The optimization region is selected through the panel acoustic contribution(PAC)analysis.Next,to reduce the normal speed in the optimization region,topology optimization is performed.According to the topology optimization results,four different noise reduction structures are added to the gearbox,and the low-noise optimization models are established respectively.Finally,by measuring the radiated noise of the gearbox before and after optimization under a given working condition,the validity of the radiated noise prediction method and the low-noise optimization design method are verified by comparing the simulation and experimental data.A comparison of the four optimization models proves that the noise reduction effect can be achieved only by adding a noise reduction structure to the center of the density nephogram.

Numerical simulation and experimental verification of solar seasonal soil thermal storage

To analyze the characteristics of solar seasonal soil thermal storage in a solar-ground coupled heat pump system (SGCHPS) in severe cold area,the software FLUENT was used to establish the three-dimensional unsteady state fluid-solid coupling mathematical model of multi-well ground heat exchanger (MWGHE).The User-Defined Functions (UDF) of solar collector and plate heat exchanger were written and dynamically loaded into the model of MWGHE as the boundary conditions.In this way,the dynamic simulation of solar seasonal soil thermal storage was realized.The comparison of simulative and experimental results showed that the overall variation trend of simulative and experimental values achieves a good agreement with time;the relative errors of simulated parameters are all in the allowable range.Therefore,it can be obtained that the models established can be applied in the investigation of performance of solar seasonal soil thermal storage.At the same time,it provides a theoretical basis for the study of heating in SGCHPS and soil heat balance analysis after long-time thermal storage and extraction.

Integrated network pharmacology and experimental verification to explore the mechanism of Sangqi Qingxuan formula against hypertensive vascular remodeling

Objective: To investigate the bioactive components of Sangqi Qingxuan formula(SQQX), predict the pharmacological targets, and explore the mechanism of hypertensive vascular remodeling(HVR).Methods: Network pharmacology was adopted to predict how SQQX acts in HVR. The effectiveness was assessed by blood pressure measurements and pathological morphology observation based on a spontaneously hypertensive rat model, while the mechanism of SQQX on HVR was validated by immunohistochemistry(IHC) and western blot(WB) according to the results of network pharmacology.Results: There were 130 bioactive components of SQQX and 231 drug targets predicted by the Traditional Chinese Medicine Systems Pharmacology Database. Subsequently, 181 common targets were identified for SQQX against HVR, with TP53, MAPK1, and AKT1 as the core targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses was employed to identify the top 20 enriched functions and the top 20 pathways(P <.01). Finally, the key role of the ERK/MAPK signaling pathway in HVR was determined. The in vivo results suggested that SQQX reduced systolic blood pressure and increased the ratio of thoracic aortic wall thickness to lumen diameter. Additionally, compared with the model group, SQQX increased the expression of smooth muscle 22 alpha(IHC: P <.001;WB:P <.05) and decreased the expression of osteopontin(IHC: P <.001;WB: P <.05), ERK1/2(IHC: P <.001;WB: ERK1 & ERK2, all P <.05), p-ERK1/2(IHC: P <.001;WB: ERK1 & ERK2, all P <.05), and the ratio of pERK1/2 to ERK1/2 protein(IHC: P <.001).Conclusions: SQQX, which has multiple bioactive ingredients and potential targets, is an effective treatment for HVR. The mechanism of antihypertensive and vascular protection may be related to the inhibition of phenotypic transformation of vascular smooth muscle cells and the ERK/MAPK signaling pathway.

Numerical simulation and experimental verification of the restraint intensity of pipeline girth welding joint

The restraint intensity （RI） of the pipeline girth welding joint was investigated using finite element method and experimental method to predict the cold cracking susceptibility of pipeline steel. The distribution of RI along the girth weld was investigated to study the influence of welding position on the RL Subsequently, the effects of outer diameter （OD） and wall thickness of pipeline on the RI were studied with ABAQUS software. The results show that the RI is almost independent of welding position. The RI increased with the increasing wall thickness but decreased with the increasing OD. A prediction model of Rl was developed based on the effects of the OD and the wall thickness. It has been found that the predicted RIs were in good agreement with the experimental values. The maximum fractional error between the predicted RI and the experimental values was just about 10%. h was indicated that the errors were mainly caused by the heterogeneous of the weld bead.

Bioinformatic Analysis and Experimental Verification of QJHGD on Caerulein-induced Inflammatory Response in SAP Model Rats Based on TLR4/NF-κB/My D88 Pathway

[Objectives]To conduct bioinformatic analysis and experimental verification of Qingjie Huagong Decoction(QJHGD)on caerulein-induced inflammatory response in severe acute pancreatitis(SAP)model rats based on TLR4/NF-κB/MyD88 pathway.[Methods]The effective component groups and potential targets of QJHGD were collected by the network pharmacology method.A drug-component-target network was constructed.The GO and KEGG of targets were enriched and analyzed with the aid of Metascape database,and the target pathway related to SAP inflammation was screened.The SAP rat model was established by caerulein combined with lipopolysaccharide,and QJHGD was intragastrically administered.Pancreatic tissue was observed by HE staining.In addition,enzyme-linked immunosorbent assay and immunohistochemistry were used to verify the anti-inflammatory effect of QJHGD on SAP rats and its regulatory effect on TLR4/NF-κB/MyD88 target pathway.[Results]A total of 105 active components of QJHGD and 148 key targets of SAP were predicted and screened;KEGG was enriched in 320 different pathways including toll-like receptor and NF-κB classical pathways.Animal experiment verified that QJHGD reduced serum amylase,serum lipase activity,IL-6,TNF-αlevels in SAP rats;HE staining showed the effect of QJHGD on the pathological changes of pancreas,and QJHGD inhibited the positive expression of key proteins of TLR4,NF-κB and MyD88 in the inflammatory transduction pathway.[Conclusions]The mechanism of QJHGD improving pancreatic injury in SAP rats may be related to down-regulating the expression of key proteins in the TLR4/NF-κB/MyD88 pathway.

Visual Passive Ranging Method Based on Re-entrant Coaxial Optical Path and Experimental Verification

To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coaxial optical path is presented. The target image is obtained using double cameras with coaxial optical path. Since there is imaging optical path difference between the cameras, the images are different. In comparison of the image differences, the target range could be reversed. The principle of the ranging method and the ranging model are described. The relationship among parameters in the ranging process is analyzed quantitatively. Meanwhile,the system composition and technical realization scheme are also presented. Also, the principle of the method is verified by the equivalent experiment. The experimental results show that the design scheme is correct and feasible with good robustness. Generally, the ranging error is less than 10% with good convergence. The optical path is designed in a re-entrant mode to reduce the volume and weight of the system. Through the coaxial design,the visual passive range of the targets with any posture can be obtained in real time. The system can be widely used in electro-optical countermeasure and concealed photoelectric detection.

Vehicle Off-road Experimental System Development and Verification Based on the Labview

The problems in the vehicle off-road experiment, such as various kinds of expensive instruments and diffi- culty in matching the input and the output signals of the vehicle status which cause useless data acquired. On the basis of considering the test functions and experimental cost, this paper has developed a vehicle off-road experimental system basing on the Labview. This system can complete various kinds of signal acquisition in one experimental sys- tem and automatically restore the data by types. This solves the problem of real time matching between the input and the output signals, making sure that the data won＇t be confused as the experimental increase, so as to level the ex- perimental efficiency and data accuracy. This system has been used to the experiment of some armored vehicles. The analysis of the data has verified the reliability of the system.

Investigation of anisotropic strength criteria for layered rock mass

Layered rock mass is a type of engineering rock mass with sound mechanical anisotropy,which is generally unfavorable to the stability of underground works.To investigate the strength anisotropy of layered rock,the Mohr-Coulomb and Hoek-Brown criteria are introduced to establish the two transverse isotropic strength criteria based on Jaeger's single weak plane theory and maximum axial strain theory,and parameter determination methods.Furthermore,the sensitivity of strength parameters(K 1,K 2,and K 3)that are used to characterize the anisotropy strength of non-sliding failure involved in the strength criteria and confining pressure are investigated.The results demonstrate that strength parameters K 1 and K 2 affect the strength of layered rock samples at all bedding angles except for the bedding angle of 90°and the angle range that can cause the shear sliding failure along the bedding plane.The strength of samples at any bedding angle decreases with increasing K 1,whereas the opposite is for K 2.Except for bedding angles of 0°and 90°and the bedding angle range that can cause the shear sliding along the bedding plane,K 3 has an impact on the strength of rock samples with other bedding angles that the specimens'strength increases with increase of K 3.In addition,the strength of the rock sample increases as confining pressure rises.Furthermore,the uniaxial and triaxial tests of chlorite schist samples were carried out to verify and evaluate the strength criteria proposed in the paper.It shows that the predicted strength is in good agreement with the experimental results.To test the applicability of the strength criterion,the strength data of several types of rock in the literature are compared.Finally,a comparison is made between the fitting effects of the two strength criteria and other available criteria for layered rocks.

Mechanism of Mingjing Granules in Treating Wet Age-Related Macular Degeneration Based on Network Pharmacology and Experimental Verification

Objective:To analyze the potential mechanism of Mingjing granules in the treatment of wet age-related macular degeneration(wAMD)based on the research methods of network pharmacology and molecular docking approach and to provide a new reference for the currently limited treatment of wAMD.Materials and Methods:We searched TCMSP,GeneCards,OMIM,PharmGkb,TTD,and DrugBank database to screen the main active ingredients of Mingjing granules and their therapeutic targets of wAMD.The network of active components and targets was constructed using Cytoscape3.6.1 software,which was also used for the topological analysis of target genes.The network of Protein-Protein Interactions(PPI)was mapped using the String platform.We also used R language to do the Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway for additional analysis.Molecular docking studies were finished by Chemoffice,Autodock,and Pymol.Finally,the efficacy of the Mingjing granules was examined in animal experiments,in which we used enzyme-linked immunosorbent assay to the contents of vascular endothelial growth factor(VEGF)and matrix metalloproteinase-9(MMP-9)levels in peripheral blood.Results:Active compounds,including quercetin,lignocaine,and kaempferol,were found.PPI network analysis showed that tumor necrosis factor(TNF),MMP-9,epidermal growth factor(EGF),prostaglandin-endoperoxide synthase 2(PTGS2),and caspase-3(CASP3)were related to both Mingjing granules and wAMD.GO and KEGG pathway analysis showed that these targets were mainly involving lipids and atherosclerosis,TNF,and interleukin-17(IL-17)signaling pathways.Docking studies suggested that quercetin and luteolin can fit in the binding pocket of four target proteins(CASP3,EGF,PTGS2,and TNF).In the vivo experiment,the Mingjing granules were found to be effective on the expression of VEGF and MMP-9 in peripheral blood.Conclusions:This study initially reveals the multi-constituent,multi-target,and multi-pathway mechanism of action of Mingjing granules in the treatment of wAMD and implies the inhibition of choroidal neovascularization may be related to the expression of VEGF and MMP-9.

Numerical and Experimental Study of a Tornado Mixer

A new design of a selective catalytic reduction(SCR)mixer called tornado was developed for a heavy-duty diesel engine to solve the urea deposition problem.A combination of CFD simulation and experimental studies was used to comprehensively evaluate the performance of the tornado mixer.According to the numerical simulations,this mixer can improve the front surface flow uniformity of the SCR carrier by 6.67%and the NH3 distribution uniformity by 3.19%compared to a traditional mixer.Similarly,steady state SCR conversion efficiency test results have shown that the tornado mixer can increase the average SCR conversion efficiency by 1.73%compared to a traditional mixer.Therefore,the tornado mixer outperforms traditional mixers in terms of mixing uniformity,resistance to deposition and impact on NOX emissions.In addition,a dimensionless parameter,the“limiting deviation rate”,is proposed in the present study to improve the mixing uniformity assessment method for SCR mixers(with the explicit intent to evaluate the mixing uniformity more accurately).

Comparison between experimental and analytical results for seesaw energy dissipation systems using fluid viscous dampers

This paper presents results of experimental and numerical investigations of a seesaw energy dissipation system （SEDS） using fluid viscous dampers （FVDs）. To confirm the characteristics of the FVDs used in the tests, harmonic dynamic loading tests were conducted in advance of the flee vibration tests and the shaking table tests. Shaking table tests were conducted to demonstrate the damping capacity of the SEDS under random excitations such as seismic waves, and the results showed SEDSs have sufficient damping capacity for reducing the seismic response of flames. Free vibration tests were conducted to confirm the reliability of simplified analysis. Time history response analyses were also conducted and the results are in close agreement with shaking table test results.

Efficacy of Lushi Runzao decoction(路氏润燥汤)on ameliorating Sjogren's syndrome:a network pharmacology and experimental verification-based study

OBJECTIVE:To investigate the possible mechanism underlying the effect of the Lushi Runzao decoction(路氏润燥汤)on Sjogren's syndrome using network pharmacology and to verify the mechanisms via animal experiments.METHODS:Available biological data on each drug in the Lushi Runzao decoction were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform,and the target proteins of Sjogren's syndrome were retrieved from the GeneCards database.Information regarding Sjogren's syndrome and the targets of the drugs were compared to obtain overlapping elements.This information was imported into the STRING platform to obtain a proteinprotein interaction network diagram,following which a“component-target”network diagram was constructed using screened drug components and target information via Cytoscape software.The database for annotation,visualization,and integrated discovery was used for Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathways analyses.Pathway information predicted by network pharmacology was verified using animal experiments.RESULTS:The Lushi Runzao decoction ameliorated Sjogren's syndrome mainly by influencing tumor necrosis factor as well as certain cytokines and chemokines.The decoction also influenced the interleukin-17 and advanced glycosylation end products(AGE)-receptor for AGE signaling pathways.CONCLUSION:The Lushi Runzao decoction ameliorates Sjogren's syndrome via multiple targets and multiple signaling pathways.Network pharmacology is useful for making a comprehensive prediction regarding the efficacy of the Lushi Runzao decoction,and this information may be helpful in clinical research.

Refined modeling and experimental verification of a torque motor for an electro-hydraulic servo valve

The Permanent Magnet Torque Motor(PMTM)is the key electro-mechanical conversion device in an Electro-Hydraulic Servo Valve(EHSV).In this work,a refined model of a PMTM is developed,considering the non-working air-gaps between the upper or lower yoke and the armature,the fringing effect at the limiting holes,and the nonlinear permeability of soft magnetic material.Based on the refined model,the influences of various factors on the calculation accuracy of the magnetic flux at the pole surfaces of the armature and the output torque are investigated.For verifying the validity of the refined model,a Finite Element Analysis(FEA)of the PMTM is conducted,and a test platform is constructed.Compared with existing models,the refined model can better reveal the intrinsic mechanism of the PMTM,and its calculations are more consistent with the FEA results.The experimental results of the armature deflection displacement show that the refined model can accurately describe the output characteristics of the PMTM.

Numerical simulation and experimental verification on downwash air flow of six-rotor agricultural unmanned aerial vehicle in hover

Recently,multi-rotor unmanned aerial vehicle(UAV)becomes more and more significantly irreplaceable in the field of plant protection against diseases,pests and weeds of crops.The easy takeoff and landing performance,hover function and high spraying efficiency of UAV are urgently required to spray pesticide for crop timely and effectively,especially in dispersed plots and hilly mountains.In such situations,the current researches about UAV spray application mainly focus on studying the influence of the UAV spraying parameters on the droplet deposition,such as operation height,operation velocity and wind velocity.The deposition and distribution of pesticide droplets on crops which depends on installation position of nozzle and airflow distribution characteristics of UAV are directly related to the control effect of pesticide and crop growth in different growth periods.As a preliminary step,this study focuses on the dynamic development law and distribution characteristics of the downwash air flow for the SLK-5 six-rotor agricultural UAV.Based on compressible Reynolds-averaged Navier-Stokes(RANS)equations with an RNG k-εturbulence model and dynamic mesh technology,the efficient three-dimensional computational fluid dynamics(CFD)method was established to analyze the flow field distribution characteristics of UAV in hover.Then the unsteady interaction flow field of the wing was investigated in detail.The downwash wind speed of the marked points for the SLK-5 UAV in hover was also tested by weather tracker.It was found that the maximum velocity value of the downwash flow was close to 10 m/s;the z-direction velocity was the main body of the wind velocity in the downwash airflow,and the comparison of the wind velocity experiment test and simulation showed that the relative error was less than 12%between the experimental and simulated values of the z-direction velocity at the marked points.Then the flow characteristics of the longitudinal and cross section were analyzed in detail,the results obtained can be used as a reference for drift and sedimentation studies for multi-rotor unmanned aerial vehicle.

Numerical and Experimental Investigation on Heat Propagation Through Composite Sinter Bed With Non-Uniform Voidage:Part Ⅰ Mathematical Model and Its Experimental Verification

The mechanisms of heat transfer through the sinter beds of the MEBIOS process are discussed and their comprehensive mathematical model is proposed. The MEBIOS process, the concept of which has been proposed ear- lier by the authors, allows using both coarse and fine particles of iron ores in the same sinter bed. The study includes two parts. The first part describes the model content and the results of its experimental verification. The model ac- counts for coal combustion, limestone decomposition, moisture evaporation/condensation, and melting/solidifying of solid phases. The model predictions are in good agreement with the experimental data. Typical numerical results of the sintering process and the key parameters influencing the process efficiency are discussed in the second part of the study.

Comparison of adaptive structural damage identification techniques in nonlinear hysteretic vibration isolation systems

Early structural damage identification to obtain an accurate condition assessment can assist in the reprioritization of structural retrofitting schedules in order to guarantee structural safety. Nowadays, seismic isolation technology has been applied in a wide variety of infrastructure, such as buildings, bridges, etc., and the health conditions of these nonlinear hysteretic vibration isolation systems have received considerable attention. To effectively detect structural damage in vibration isolation systems based on vibration data, three time-domain analysis techniques, referred to as the adaptive extended Kalman filter （AEKF）, adaptive sequential nonlinear least-square estimation （ASNLSE） and adaptive quadratic sum-sqnares error （AQSSE）, have been investigated. In this research, these analysis techniques are compared in terms of accuracy, convergence and efficiency, for structural damage detection using experimental data obtained through a series of laboratory tests based on a base-isolated structural model subjected to E1 Centro and Kobe earthquake excitations. The capability of the AEKF, ASNLSE and AQSSE approaches in tracking structural damage is demonstrated and compared.