面向类别不平衡语义分割的损失函数的研究

在图像语义分割的任务中,数据集的类别不平衡分布是一种普遍存在的现象;通过构造更加有效的损失函数来减轻其带来的不利影响是具有较大研究价值的。以损失函数为研究对象,利用训练样本像素的空间分布特性和相关性,改进了Focal损失函数的尺度度量方法,提出了一个基于迭代批次的权重自适应调整的Adapt-Focal损失函数。以类别不平衡的SAR图像数据集GDUT-Nansha为实验对象,采用三个经典的卷积神经网络DeepLabV3+、U-Net和RWL-ENet完成了定量实验。实验结果表明,所提出的Adapt-Focal损失函数相比于CE、FL、dfl、acw、lovász和softiou损失函数,有效提高了少样本地物类别裸地和道路的分割精度IoU和PA值;同时,整体分割精度指标mPA和mIoU均得到较大幅度的提高。验证了Adapt-Focal损失函数在类别不平衡图像语义分割中的有效性。

Physical and mechanical properties and microstructures of submarine soils in the Yellow Sea

In recent years,the exploration of seabed has been intensified,but the submarine soils of silt and sand in the Yellow Sea area have not been well investigated so far.In this study,the physical and mechanical properties of silt and sand from the Yellow Sea were measured using a direct shear apparatus and their microstructures were observed using a scanning electron microscope.The test results suggest that the shear strength of silt and sand increases linearly with the increase of normal stress.Based on the direct shear test,the scanning electron microscope was used to observe the section surface of sand.It is observed that the section surface becomes rough,with many“V”‐shaped cracks.Many particles appear on the surface of the silt structure and tend to be disintegrated.The X‐ray diffraction experiment reveals that the sand and silt have different compositions.The shear strength of sand is slightly greater than that of silt under high stress,which is related to the shape of soil particles and the mineral composition.These results can be a reference for further study of other soils in the Yellow Sea;meanwhile,they can serve as soil parameters for the stability and durability analyses of offshore infrastructure construction.

Boron nitride silicone rubber composite foam with low dielectric and high thermal conductivity

Silicone rubber(SR)is widely used in the field of electronic packaging because of its low dielectric properties.In this work,the porosity of the SR was improved,and the dielectric constant of the SR foam was reduced by adding expanded microspheres(EM).Then,the thermal conductivity of the system was improved by combining the modified boron nitride(f-BN).The results showed that after the f-BN was added,the dielectric constant and dielectric loss were much lower than those of pure SR.Micron-sized modified boron nitride(f-mBN)improved the dielectric and thermal conductivity of the SR foam better than that of nano-sized modified boron nitride(f-nBN),but f-nBN improved the volume resistivity,tensile strength,and thermal stability of the SR better than f-mBN.When the mass ratio of f-mBN and fnBN is 2:1,the thermal conductivity of the SR foam reaches the maximum value of 0.808 W·m^(-1)·K^(-1),which is 6.5 times that before the addition.The heat release rate and fire growth index are the lowest,and the improvement in flame retardancy is mainly attributed to the high thermal stability and physical barrier of f-BN.

The prognostic value of collateral circulation in coronary chronic total occlusion underwent percutaneous coronary intervention

BACKGROUND The prognostic value of coronary collateral circulation(CC)in patients undergoing chronic total occlusion(CTO)percutaneous coronary intervention(PCI)is underdetermined.The purpose of the study was to assess the prognostic value of current two CC grading systems and their association with long-term outcomes in patients with CTO underwent PCI.METHODS We consecutively enrolled patients with single-vessel CTO underwent PCI between January 2010 and December2013.All patients were categorized into well-developed or poor-developed collaterals group according to angiographic Werner's CC(grade 2 vs.grade 0–1)or Rentrop(grade 3 vs.grade 0–2)grading system.The primary endpoint was 5-year cardiac death.RESULTS Of 2452 enrolled patients,the overall technical success rate was 74.1%.Well-developed collaterals were present in686 patients(28.0%)defined by Werner's CC grade 2,and in 1145 patients(46.7%)by Rentrop grade 3.According to Werner's CC grading system,patients with well-developed collaterals had a lower rate of 5-year cardiac death compared with those with poordeveloped collaterals(1.6%vs.3.3%,P=0.02),those with suboptimal recanalization was associated with higher rate of 5-year cardiac death compared with optimal recanalization(4.7%vs.0.8%,P=0.01)and failure patients(4.7%vs.1.6%,P=0.12).However,the similar effect was not shown in Rentrop grading system.CONCLUSIONS In patients with the single-vessel CTO underwent PCI,well-developed collaterals by Werner's CC definition were associated with lower rate of 5-year cardiac death.Werner's CC grading system had a greater prognostic value than Rentrop grading system in patients with CTO underwent PCI.

A Network Pharmacology Study on Active Components and Targets of Citri Reticulatae Pericarpium for Treating Keloids

[Objectives]To investigate the mechanisms and pharmacologic effects of Citri Reticulatae Pericarpium against keloids by network pharmacology systematically.[Methods]TCMSP,Uniprot and BATMAN-TCM databases were used to obtain the active constituents and targets of Citri Reticulatae Pericarpium."Keloid"was used as key word to search for related therapeutic targets from Drug Bank,OMIM,TTD,and GEO databases.The Chinese medicine compound-target network was constructed by Cytoscape software.Besides,gene ontology(GO)and Kyoto Encyclopedia of genes and genome enrichment analysis were also performed.Afterward,Discovery Studio software was used to assess the interaction of key components and genes.[Results]Five active components of Citri Reticulatae Pericarpium,773 compound targets and 676 keloid treatment targets were obtained in the databases.After the intersection,there are 47 targets of Citri Reticulatae Pericarpium for treating keloids.Hub genes were identified such as MMP9,IL6,TNF,TP53,and VEGFA,which were enriched in tumor necrosis factor-α,nuclear factor kappa-B,and other signaling pathways.The molecular docking stimulation confirmed the interaction between the MMP9 and three components of Citri Reticulatae Pericarpium.[Conclusions]Citri Reticulatae Pericarpium may play an important role in treating keloids through modulating genes and signaling pathways.The present study sheds light on the mechanisms of active compounds of Citri Reticulatae Pericarpium for the treatment of keloids.

新型双层包裹聚磷酸铵的设计及其在耐老化阻燃交联聚乙烯复合材料中的应用

研究采用双层包裹聚磷酸铵来提高交联聚乙烯(XLPE)复合材料的力学性能、耐老化性和阻燃性。将聚磷酸铵(APP)用二氧化硅包裹,然后用受阻苯酚抗氧化剂3-(3,5-二叔丁基-4羟基苯基)(AO)接枝,制备双层包裹阻燃剂(MCAPP)。由于MCAPP和XLPE基体具有良好的相容性,提高了XLPE/MCAPP/CFA(XLPE-4)的拉伸强度和断裂伸长率。在135℃老化14天后,XLPE-4复合材料的断裂伸长率保留率达到61.1%,显著高于XLPE-1(2.6%)。这说明MCAPP可以提高XLPE电缆复合材料的耐老化性能。与XLPE-1相比,XLPE-4的最大烟密度和峰值放热速率分别降低了54.9%和89.7%。因此,双层包裹的抗氧化策略为获得高性能的XLPE复合材料提供了一个很好的途径。

Recent Advances in Understanding Multi-scale Climate Variability of the Asian Monsoon

Studies of the multi-scale climate variability of the Asian monsoon are essential to an advanced understanding of the physical processes of the global climate system.In this paper,the progress achieved in this field is systematically reviewed,with a focus on the past several years.The achievements are summarized into the following topics:(1)the onset of the South China Sea summer monsoon;(2)the East Asian summer monsoon;(3)the East Asian winter monsoon;and(4)the Indian summer monsoon.Specifically,new results are highlighted,including the advanced or delayed local monsoon onset tending to be synchronized over the Arabian Sea,Bay of Bengal,Indochina Peninsula,and South China Sea;the basic features of the record-breaking mei-yu in 2020,which have been extensively investigated with an emphasis on the role of multi-scale processes;the recovery of the East Asian winter monsoon intensity after the early 2000s in the presence of continuing greenhouse gas emissions,which is believed to have been dominated by internal climate variability(mostly the Arctic Oscillation);and the accelerated warming over South Asia,which exceeded the tropical Indian Ocean warming,is considered to be the main driver of the Indian summer monsoon rainfall recovery since 1999.A brief summary is provided in the final section along with some further discussion on future research directions regarding our understanding of the Asian monsoon variability.

Sandwich structured ultra-strong-heat-shielding aerogel/copper composite insulation board for safe lithium-ion batteries modules

The fire hazard of lithium-ion batteries(LIBs)modules is extremely serious due to their high capacity.Moreover,once a battery catches fire,it can easily result in a fire of the entire LIBs modules.In this work,a sandwich structure composite thermal insulation(STI)board(copper//silica dioxide aerogel//copper)with the advantages of low thermal conductivity(0.031 W m-1K-1),low surface radiation emissivity(0.1)and good thermal convection inhibition effect has been designed.The thermal runaway(TR)occurrence time of adjacent LIBs increases from 1384 s to more than 6 h+due to the protection of STI board.No TR propagation occurs within LIBs modules with protect of a STI board when a battery catches fire.The ultra-strong-heat-shielding mechanism of STI board has been revealed.The TR propagation of LIBs modules has been insulated effectively by STI board through reducing the heat transfer of convection,conduction and radiation.The air flow rate between the heater and LIBs and radiant heat absorbed by LIBs decrease by 63.5%and 35.1%with protection of STI board,respectively.A high temperature difference inside the STI board is also formed.This work provides direction for the designing of safe thermal insulation board for LIBs modules.

Superior resistance to alkali metal potassium of vanadium-based NH_(3)-SCR catalyst promoted by the solid superacid SO_(4)^(2-)-TiO_(2)

The significant decrease of acid sites caused by alkali metal poisoning is the major factor in the deactivation of commercial V_(2)O_(5)-WO_(3)/TiO_(2)NH_(3)-SCR catalysts.In this work,the solid superacid SO_(4)^(2-)-TiO_(2) modified by sulfate radicals,was selected as the catalyst support,which showed superior potassium resistance.The physicochemical properties and K-poisoning resistance of the V_(2)O_(5)-WO_(3)/SO_(4)^(2-)-TiO_(2)(VWSTi) catalyst were carried out by XRD,BET,H2-TPR,NH3-TPD,XPS,in situ DRIFTS and TG.The results pointed out that the introduction of SO_(4)^(2-)significantly increased the NH3-SCR catalytic activity at high temperatures,with an exceptionally high NO_(x) conversion over 90% between 275℃ and 500℃.When 0.5%(mass) K_(2)O was doped on the catalysts,the catalytic performance of the traditional V_(2)O_(5)-WO_(3)/TiO_(2)(VWTi) catalyst decreased significantly,while the VWSTi catalyst could still maintain a NOxconversion over 90%in the range of 300–500℃.The characterizations suggested that the support of SO_(4)^(2-)-TiO_(2) greatly increased the number of acidic sites,thereby enhancing the adsorption capacity of the reactant NH_(3).The results above demonstrated a potential approach to achieve superior potassium resistance for NH3-SCR catalysts using solid superacid.

Impact of seepage flow on sediment resuspension by internal solitary waves:parameterization and mechanism

Sediment incipient motion is the first step in sediment resuspension.Previous studies ignored the effect of seepage flow on the mobility of sediment particles and simplified the seabed surface as a rigid boundary.A flume experiment was designed to innovatively divide the seabed into two parts to control the dynamic response of the seabed and control the seepage conditions.In the experiment,the seabed sediments and the amplitude of internal solitary waves(ISWs)were changed to compare and analyze the impact of seepage flow on the sediment resuspension by shoaling ISWs.Moreover,parametric research and verification were carried out.Results indicate that seepage flow can greatly influence fine sand,promote sediment resuspension,and increase the amount of suspension by two times on average.However,seepage flow had a little effect on the suspension of clayey silt and sandy silt.Besides,seepage force was added to the traditional gravity,drag force,and uplift force,and the parameterization of threshold starting shear stress of coarse-grained sediments was developed.The results of this parameterization were verified,and seepage force was critical to parameterization.The threshold starting shear stress was reduced by 54.6%after increasing the seepage force.The physical mechanism of this process corresponded to the vertical reciprocating transient seepage in and out the seabed interface caused by the wave-induced transient excess pore water pressure.This quantitative study on seepage flow for shear stress of coarse-grained sediments induced by ISWs is critical to geohazard assessment.

Different clinical characteristics and outcomes of hypertrophic cardiomyopathy with and without hypertension:seeking the truth

OBJECTIVE To determine the different clinical characteristics and outcomes of hypertrophic cardiomyopathy(HCM)patients with and without hypertension(HT).METHODS A total of 696 HCM patients were included in this study and all HCM diagnoses were confirmed by the genetic test.Patients were analyzed separately in the septal reduction therapy(SRT)cohort and the non-SRT cohort.The primary endpoint was cardiovascular death and the secondary endpoint was all-cause death.Outcome analyses were conducted to evaluate the associations between HT and outcomes in HCM.Medications before enrollment and at discharge were collected in the post-hoc analyses.RESULTS HCM patients without HT were younger,had a lower body mass index,were more likely to have a family history of HCM,and had a smaller left ventricular(LV)end-diastolic diameter than those with HT in both cohorts.A thicker LV wall,a higher level of N-terminal pro-B-type natriuretic peptide,and a higher extent of LV late gadolinium enhancement were additionally observed in patients without HT in the non-SRT cohort.The presence of HT did not alter the distribution pattern of late gadolinium enhancement,as well as the constituent ratio of eight disease-causing sarcomeric gene variants in both cohorts.Outcome analyses showed that in the non-SRT cohort,patients without HT had higher risks of cardiovascular death(HR=2.537,P=0.032)and all-cause death(HR=3.309,P=0.032).While such prognostic divergence was not observed in the SRT cohort.Further post-hoc analyses in the non-SRT cohort found that patients without HT received fewer non-dihydropyridine calcium channel blockers and angiotensinconverting enzyme inhibitors/angiotensin receptor blockers before enrollment and at discharge.CONCLUSIONS HCM patients without HT had worse clinical conditions and higher mortality than patients with HT overall,which may result from active medical therapy in HT patients.Active SRT may have a substantial de-risking effect on patients meeting the indications.

Prolonging dual antiplatelet therapy improves the long-term prognosis in patients with diabetes mellitus undergoing complex percutaneous coronary intervention

OBJECTIVE To investigate the optimal duration of dual antiplatelet therapy(DAPT)in patients with diabetes mellitus(DM)requiring complex percutaneous coronary intervention(PCI).METHODS A total of 2403 patients with DM who underwent complex PCI from January to December 2013 were consecutively enrolled in this observational cohort study and divided according to DAPT duration into a standard group(11-13 months,n=689)and two prolonged groups(13-24 months,n=1133;>24 months,n=581).RESULTS Baseline characteristics,angiographic findings,and complexity of PCI were comparable regardless of DAPT duration.The incidence of major adverse cardiac and cerebrovascular event was lower when DAPT was 13-24 months than when it was 11-13 months or>24 months(4.6%vs.8.1%vs.6.0%,P=0.008),as was the incidence of all-cause death(1.9%vs.4.6%vs.2.2%,P=0.002)and cardiac death(1.0%vs.3.0%vs.1.2%,P=0.002).After adjustment for confounders,DAPT for 13-24 months was associated with a lower risk of major adverse cardiac and cerebrovascular event[hazard ratio(HR)=0.544,95%CI:0.373-0.795]and all-cause death(HR=0.605,95%CI:0.387-0.944).DAPT for>24 months was associated with a lower risk of all-cause death(HR=0.681,95%CI:0.493-0.942)and cardiac death(HR=0.620,95%CI:0.403-0.952).The risk of major bleeding was not increased by prolonging DAPT to 13-24 months(HR=1.356,95%CI:0.766-2.401)or>24 months(HR=0.967,95%CI:0.682-1.371).CONCLUSIONS For patients with DM undergoing complex PCI,prolonging DAPT might improve the long-term prognosis by reducing the risk of adverse ischemic events without increasing the bleeding risk.

Measurements of the effective mass transfer areas for the gas–liquid rotating packed bed

Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaOH–CO_(2) chemical absorption method, the aevalues of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence.The radius of packing is the dominant equipment factor to affect aevalue. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the aevalue. Moreover, the measured ae/ap(effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.

辐照对中华鳖裙边和肌肉挥发性成分的影响

为探究不同辐照剂量对中华鳖裙边和肌肉风味的影响,采用顶空固相微萃取结合气质联用仪(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)检测分析辐照处理后裙边和肌肉中挥发性成分的变化,通过气味活度值(odor activity value,OAV)和正交偏最小二乘判别分析(orthogonal partial least squares-discriminant analysis,OPLS-DA)确定关键风味物质和辐照异味产生情况。结果表明,裙边和肌肉中分别检测到38种、27种挥发性物质,其中壬醛、癸醛、辛醛、苯乙醛、香叶基丙酮、β-环柠檬醛、十一醛和己醛对中华鳖风味贡献较大。经3 kGy及以下辐照剂量处理后,壬醛、辛醛、癸醛等腥味物质的OAV值降至较低,改善了整体风味,7 kGy及以上时,产生了具脂肪气味的(E,E)-2,4-癸二烯醛、(E)-2-壬烯醛、(E)-2-十二烯醛等异味物质。OPLS-DA在裙边中筛选到5种特征标志物[变量重要性(variable influence on projection,VIP)值大于1],分别为壬醛、苯甲醛、苯乙烯、苯乙醇和β-环柠檬醛,在肌肉中筛选到苯甲醛、(E)-2-十二烯醛、β-环柠檬醛、苯乙醇和壬醛5种标志物。OPLS-DA和聚类分析表明,可根据特征标志物含量有效区分不同辐照剂量样品,3 kGy时裙边和肌肉能较好保持原有风味,且有效减轻了腥味和油脂味,7 kGy和9 kGy时,辐照异味较明显。该研究可为中华鳖加工提供参考。

Comprehensive and deep profiling of the plasma proteome with protein corona on zeolite NaY

Proteomic characterization of plasma is critical for the development of novel pharmacodynamic biomarkers.However,the vast dynamic range renders the profiling of proteomes extremely challenging.Here,we synthesized zeolite NaY and developed a simple and rapid method to achieve comprehensive and deep profiling of the plasma proteome using the plasma protein corona formed on zeolite NaY.Specifically,zeolite NaY and plasma were co-incubated to form plasma protein corona on zeolite NaY(NaY-PPC),followed by conventional protein identification using liquid chromatography-tandem mass spectrometry.NaY was able to significantly enhance the detection of low-abundance plasma proteins,minimizing the“masking”effect caused by high-abundance proteins.The relative abundance of middleand low-abundance proteins increased substantially from 2.54%to 54.41%,and the top 20 highabundance proteins decreased from 83.63%to 25.77%.Notably,our method can quantify approximately 4000 plasma proteins with sensitivity up to pg/mL,compared to only about 600 proteins identified from untreated plasma samples.A pilot study based on plasma samples from 30 lung adenocarcinoma patients and 15 healthy subjects demonstrated that our method could successfully distinguish between healthy and disease states.In summary,this work provides an advantageous tool for the exploration of plasma proteomics and its translational applications.

Expression profiles of circulating tRNA-derived small RNAs and their potential role in diabetes

This work aimed to reveal the expression profiles of tRNA-derived small RNAs(tsRNAs)in diabetes.Methods:Thirty-five diabetes patients and thirty-three controls were enrolled.The serum samples of 4 diabetes patients and 4 controls were subjected to tRF and tiRNA polymerase chain reaction(PCR)Array analysis.Then quantitative PCR(qPCR)validation was performed on all the samples.Bioinformatics analyses were conducted to explore their functions.Results:We found 115 tsRNAs that significantly differed between the two groups.3′tiR-080-ProTGG(mt)was selected for further qPCR validation in all participants,and it was significantly decreased in diabetes patients compared with controls.Bioinformatics analysis indicated that 3′tiR-080-ProTGG(mt)may play regulatory roles via the cyclic adenosine monophosphate(cAMP)signaling pathway in the pathogenesis and progression of diabetes.Conclusion:Hence,we report that circulating tsRNAs are dysregulated that could be involved in the pathogenesis of diabetes.

Timing of surgical operation for patients with intra-abdominal infection:A systematic review and meta-analysis

BACKGROUND Intra-abdominal infections(IAIs)is the most common type of surgical infection,with high associated morbidity and mortality rates.In recent years,due to the use of antibiotics,various drug-resistant bacteria have emerged,making the treatment of abdominal infections more challenging.Early surgical exploration can reduce the mortality of patients with abdominal infection and the occurrence of complications.However,available evidence regarding the optimal timing of IAI surgery is still weak.In study,we compared the effects of operation time on patients with abdominal cavity infection and tried to confirm the best timing of surgery.AIM To assess the efficacy of early vs delayed surgical exploration in the treatment of IAI,in terms of overall mortality.METHODS A systematic literature search was performed using PubMed,EMBASE,Cochrane Central Register of Controlled Trials,Ovid,and ScienceDirect.The systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses method.Based on the timing of the surgical operation,we divided the literature into two groups:Early surgery and delayed surgery.For the early and delayed surgery groups,the intervention was performed with and after 12 h of the initial surgical intervention,respectively.The main outcome measure was the mortality rate.The literature search was performed from May 5 to 20,2021.We also searched the World Health Organization International Clinical Trials Registry Platform search portal and ClinicalTrials.gov on May 20,2021,for ongoing trials.This study was registered with the International Prospective Register of Systematic Reviews.RESULTS We identified nine eligible trial comparisons.Early surgical exploration of patients with IAIs(performed within 12 h)has significantly reduced the mortality and complications of patients,improved the survival rate,and shortened the hospital stay.CONCLUSION Early surgical exploration within 12 h may be more effective for the treatment of IAIs relative to a delayed operation.

Effect of Bio-Based Organic‒Inorganic Hybrid Hydrogels on Fire Prevention of Spontaneous Combustion of Coals

To solve the fire accidents caused by coal combustion,this work prepared four hybrid hydrogel materials using bio-based polymers,flame retardants,and inorganic materials.Compared to pure water and 3.5 wt%MgCl_(2)solution,the as-prepared hydrogel presents good fire prevention performance.In addition,it is found that CO and CO_(2)are not produced by coal when the pyrolysis temperature is lower than 200℃.During low-temperature pyrolysis,CO is more likely to be produced than CO_(2),indicating inadequate pyrolysis behavior.At the same time,the addition of fire-preventing hydrogel can not only decrease the maximum CO_(2)concentration before the critical temperature but also prolong the corresponding time.In addition,based on the cone calorimeter test,the inhibition effects of pure water,magnesium chloride solution,and four hybrid hydrogels on heat release behavior are evaluated.It is demonstrated that different dosages of different hydrogels affected the fire prevention effect.Phosphorous-modified cellulose/silica and carrageenan/DMMP/vermiculite composite hydrogels have the weakest fire prevention effect at 20 g,which is weaker than that of water.However,the fire prevention effect of carrageenan/DMMP/vermiculite composite hydrogels exceeded that of water at 40 and 60 g.Additionally,the fire prevention effect of the sodium alginate/sepiolite/ammonium polyphosphate composite hydrogel is most significant in common tests,attributed to the intumescent flame retardant system.

乡村振兴背景下农户自媒体发展策略分析

近年,农村地区的互联网用户不断增多,农户自媒体的发展有效助推了乡村振兴战略的实施。对乡村振兴背景下农户自媒体现状进行调研发现,其发展面临着技术困境,宣传方式创意性不够,品牌打造难度较大,关注话题单一,缺乏新鲜感,内容重复、同质化,获客成本不断攀升等困境。为优化农户自媒体发展,应加强对“三农”网络媒体的组织化管理,坚持正确的内容传播导向,培养人才,注重创新营销策略。自媒体为农户提供了展现自我的平台,有利于农产品品牌的建立。

Current Status and Prospects of Drugs for Ischemic Stroke Treatment

This paper reviewed the shortcomings of conventional therapies for ischemic stroke and discussed the methods of vascular regeneration,stem cell differentiation,homing and neuronal remodeling after ischemic stroke,to provide potential therapeutic ideas for ischemic stroke.