Liquefaction and post-liquefaction behaviors of sands affected by immersion-induced degradation of crushed mudstone

A series of undrained triaxial tests was conducted to investigate the effect of crushed mudstone with the immersion-induced degradation on the liquefaction and post-liquefaction properties,and the undrained shearing behavior without precedent cyclic-loading histories of sands containing crushed mudstone.The tested materials with a main particle diameter of 2-0.85 mm were prepared by mixing sands and crushed mudstone to reach the prescribed mudstone content defined by dry mass ranging from 0% to 50%.The mixtures were subjected to immersion under a certain stress level and were subsequently tested.In addition,one-dimensional compression tests were also supplementally performed to visually observe the immersion-induced degradation of crushed mudstone.The test results mainly showed that: (1) the liquefaction resistance,the post-liquefaction undrained strength,and the undrained strength without a precedent cyclic-loading history decreased significantly with increasing mudstone content,M c ,up to 20%;(2) even a small amount of crushed mudstone affected these strengths;(3) the above-mentioned large reductions in the strengths were attributed to the immersion-induced degradation of crushed mudstone;(4) at M_(c) >20%,the liquefaction resistance increased while the significant increase in the undrained static strengths with and without precedent cyclic-loading histories was not observed;and (5) the increase in the liquefaction resistance at M_(c) >20% may have been attributed to both the gradual increase in the plasticity and the formation of the soil aggregates among deteriorated crushed mudstone,while the increase in the specimen density did not play an important role in such behavior.

Discussion on Dust Removal(Suppression)System of Crushing Station in Open-Pit Coal Mine

This paper introduces the method of coal dust treatment in crushing station and the present situation of dust removal system in typical open-pit coal mine crushing station in China,and expounds the research idea of determining comprehensive dust removal(suppression)system in crushing station inspired by the working principle of"range hood".Based on the design example and link optimization of the crush-ing station of open-pit coal mine I of Thar coalfield,this paper finally draws some conclusions on the key technologies of dust removal(suppression)system of open-pit coal mine crushing station.This study has certain reference value for the technical innovation of dust removal(suppression)system in crushing station,the realization of green mining in"crushing link",and the reduction and avoidance of ecological environment pollution in mining area.

Investigation of Carbonation of Concrete Based on Crushed Sand and Admixtures

Carbonation is a natural aging process that occurs in all types of concrete. One of its primary implications is the acceleration of steel corrosion caused by the phenomena of depassivation. The goal of this research is to investigate the carbonation of quarry sand-based concrete. The concrete is made of 100% crushed sand 0/6.3, gravel 8/15, and 15/25 from the Arab Contractor quarry in Nomayos, Cameroon, with CEM II B-P 42.5 R from CIMENCAM (Cimenteries du Cameroun). The study employed two admixtures: one with a dual superplasticizing and reducing action (Sikamen) and another with a water-repellent effect (Sika liquid). Carbonation was performed on concrete samples at the following dates: 0, 7, 14, 28, 56, 90, 180 days, one year, and six months. Carbonated concrete (CC) and non-carbonated concrete (NCC) samples are compared in terms of their physical attributes and mineralogical characteristics. The results of this investigation reveal that after more than a year and six months of carbonation, porosity decreases and permeability increases. Despite the high fineness modulus of quarry sand, the compressive strength of quarry sand-based concrete is satisfactory. Carbonation depth is relatively high on some dates, exceeding the minimal cover value for concrete reinforcement. Sikament additive increases concrete compactness and durability while decreasing permeability. Sika water repellant mixes with the lime in cement to generate complimentary crystallizations that block the mortar’s capillaries, making it watertight.

IVUS引导下Step-Crush术治疗左主干分叉病变对支架贴壁情况及患者预后的影响

目的:分析血管内超声(IVUS)引导下Step-Crush术治疗左主干分叉病变对支架贴壁情况及患者预后的影响。方法:回顾分析2021年3月—2022年12月于九江市第一人民医院总院心血管内科就诊的左主干分叉病变患者60例,根据手术方式将患者分为IVUS组(n=34,采用IVUS引导下StepCrush术)和常规组(n=26,采用常规Step-Crush术)。对比两组支架情况(最大支架直径、左主干支架长度、支架贴壁不良发生率、支架边缘夹层发生率)、球囊参数(球囊最大直径、球囊最大压力)、心功能指标[左室射血分数(LVEF)、左室舒张末内径(LVEDD)]及心血管不良事件发生率。结果:相较于常规组,IVUS组最大支架直径、左主干支架长度、球囊最大直径均更长,球囊最大压力更大(P<0.05);术后2个月,IVUS组LVEF较常规组更高,LVEDD较常规组更低,差异均有统计学意义(P<0.05);IVUS组支架贴壁不良发生率、心血管不良事件发生率均更低,差异均有统计学意义(P<0.05)。两组支架边缘夹层发生率对比,差异无统计学意义(P>0.05)。结论:IVUS应用于Step-Crush术中可改善左主干分叉病变患者支架置入情况,降低支架贴壁发生率,有效预防心血管不良事件发生。

Dynamic crushing behaviors and enhanced energy absorption of bio-inspired hierarchical honeycombs with different topologies

In order to pursue good crushing load uniformity and enchance energy absorption efficiency of conventional honeycombs, a kind of bio-inspired hierarchical honeycomb model is proposed by mimicking the arched crab shell structures. Three bio-inspired hierarchical honeycombs(BHHs) with different topologies are designed by replacing each vertex of square honeycombs with smaller arc-shaped structures. The effects of hierarchical topologies and multi-material layout on in-plane dynamic crushings and absorbed-energy capacities of the BHHs are explored based on the explicit finite element(FE) analysis.Different deformation modes can be observed from the BHHs, which mainly depend upon hierarchical topologies and impact velocities. According to energy efficiency method and one-dimensional(1D) shock theory, calculation formulas of densification strains and plateau stresses for the BHHs are derived to characterize the dynamic bearing capacity, which is consistent well with FE results. Compared with conventional honeycombs, the crushing load efficiency and energy absorption capacity of the BHHs can be improved by changing the proper hierarchical topology and multi-material layout. These researches will provide theoretical guidance for innovative design and dynamic response performance controllability of honeycombs.

Valproate reduces retinal ganglion cell apoptosis in rats after optic nerve crush

The retinal ganglion cells of the optic nerve have a limited capacity for self-repair after injury.Valproate is a histone deacetylase inhibitor and multitarget drug,which has been demonstrated to protect retinal neurons.In this study,we established rat models of optic nerve-crush injury and injected valproate into the vitreous cavity immediately after modeling.We evaluated changes in the ultrastructure morphology of the endoplasmic reticulum of retinal ganglion cells over time via transmission electron microscope.Immunohistochemistry and western blot assay revealed that valproate upregulated the expression of the endoplasmic reticulum stress marker glucose-regulated protein 78 and downregulated the expression of transcription factor C/EBP homologous protein,phosphorylated eukaryotic translation initiation factor 2α,and caspase-12 in the endoplasmic reticulum of retinal ganglion cells.These findings suggest that valproate reduces apoptosis of retinal ganglion cells in the rat after optic nerve-crush injury by attenuating phosphorylated eukaryotic translation initiation factor 2α-C/EBP homologous protein signaling and caspase-12 activation during endoplasmic reticulum stress.These findings represent a newly discovered mechanism that regulates how valproate protects neurons.

Effects of coals microscale structural features on their mechanical properties,propensity to crushing and fine dust formation

The work is dedicated to revealing the structural features of coals with different ranks,such as anthracites,metaanthracite and graphite,that determine their ability to crush and form fine dust.For this purpose,a combination of various nanoin-dentation techniques and Raman spectroscopy was used.The mechanical behavior of the selected coals was investigated by cyclic nanoindentation with increasing peak load and quasi-static loading.The alteration of the mechanical properties was studied by analysis of elastic moduli and damage indices Rw.Three groups of coals were identified based on their propensity to crushing during cyclic nanoindentation.Coals assigned to the first and second groups are characterized by local destruction in the contact zone with the indenter and the formation of a core of crushed material.Coals assigned to the third group are characterized by bulk destruction(outside the zone of contact with the indenter).In general,the ability of coals to fracture under mechanical loading decreases in the series of metamorphism due to microscale compaction of vitrinite matter.In the series of anthracite,metaanthracite and graphite,it is established that the coal matter compaction takes place for the anthracite and metaanthracite,whereas graphite reveals rather different behavior due to abrupt change of its structure.The ratios between the amorphous and crystalline phases of carbon(S)were determined by deconvolution of coals Raman spectra.The propensity of coals to crushing(a damage index Rw)increases with growth of the proportion of amorphous carbon in the coal matter.For the considered coals and metaanthracite,it is established that the proneness to destruction outside the contact zone with the indenter is determined by the ratio of amorphous and crystalline carbon of 1 and higher.When S parameter is lower than 1,the coals are being crushed only in the zone of contact with the indenter.

Dynamic crushing behavior and energy absorption of hybrid auxetic metamaterial inspired by Islamic motif art

Auxetic honeycomb structures are promising metamaterials with outstanding mechanical properties,and can be potentially used in energy absorption applications.In this study,a novel modified re-entrant hybrid auxetic metamaterial inspired by Islamic motif art is designed by integrating four-pointed double re-entrant motifs with symmetric semi-hexagonal unit cells to achieve a high energy absorption capacity(EAC).Theoretical analyses and numerical simulations are performed to examine the dynamic crushing behavior of the four-pointed double re-entrant combined structure(FDRCS).The developed finite element models(FEMs)are validated by the experiments under quasi-static compression.The deformation mode and stress-strain curves are further studied under low,medium,and high crushing velocities.The theoretically predicted plateau stress of the FDRCS under different crushing velocities is consistent with the numerical simulation results.The crushing stress and the EAC of the FDRCS are influenced by the geometric parameters and crushing velocities.The FDRCS exhibits a negative Poisson's ratio(NPR),owing to the four-point re-entrant structure(RES).Moreover,the specific energy absorption(SEA)of these structures is higher than that of nonauxetic hexagonal and auxetic re-entrant structures,owing to the generation of more plastic hinges that dissipate more energy during dynamic crushing.

Use of a tissue clearing technique combined with retrograde trans-synaptic viral tracing to evaluate changes in mouse retinorecipient brain regions following optic nerve crush

Successful establishment of reconnection between retinal ganglion cells and retinorecipient regions in the brain is critical to optic nerve regeneration.However,morphological assessments of retinorecipient regions are limited by the opacity of brain tissue.In this study,we used an innovative tissue cleaning technique combined with retrograde trans-synaptic viral tracing to observe changes in retinorecipient regions connected to retinal ganglion cells in mice after optic nerve injury.Specifically,we performed light-sheet imaging of whole brain tissue after a clearing process.We found that pseudorabies virus 724(PRV724)mostly infected retinal ganglion cells,and that we could use it to retrogradely trace the retinorecipient regions in whole tissue-cleared brains.Unexpectedly,PRV724-traced neurons were more widely distributed compared with data from previous studies.We found that optic nerve injury could selectively modify projections from retinal ganglion cells in the hypothalamic paraventricular nucleus,intergeniculate leaflet,ventral lateral geniculate nucleus,central amygdala,basolateral amygdala,Edinger-Westphal nucleus,and oculomotor nucleus,but not the superior vestibular nucleus,red nucleus,locus coeruleus,gigantocellular reticular nucleus,or facial nerve nucleus.Our findings demonstrate that the tissue clearing technique,combined with retrograde trans-synaptic viral tracing,can be used to objectively and comprehensively evaluate changes in mouse retinorecipient regions that receive projections from retinal ganglion cells after optic nerve injury.Thus,our approach may be useful for future estimations of optic nerve injury and regeneration.

Charcot-Marie-Tooth-1A and sciatic nerve crush rat models:insights from proteomics

The sensorimotor and histological aspects of peripheral neuropathies were already studied by our team in two rat models:the sciatic nerve crush and the Charcot-Marie-Tooth-1A disease.In this study,we sought to highlight and compare the protein signature of these two pathological situations.Indeed,the identification of protein profiles in diseases can play an important role in the development of pharmacological targets.In fact,Charcot-Marie-Tooth-1A rats develop motor impairments that are more severe in the hind limbs.Therefore,for the first time,protein expression in sciatic nerve of Charcot-Marie-Tooth-1A rats was examined.First,distal sciatic nerves were collected from Charcot-Marie-Tooth-1A and uninjured wild-type rats aged 3 months.After protein extraction,sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry was employed.445 proteins mapped to Swiss-Prot or trEMBL Uniprot databases were identified and quantified.Of these,153 proteins showed statistically significant differences between Charcot-Marie-Tooth-1A and wild-type groups.The majority of these proteins were overexpressed in Charcot-Marie-Tooth-1A.Hierarchical clustering and functional enrichment using Gene Ontology were used to group these proteins based on their biological effects concerning Charcot-Marie-Tooth-1A pathophysiology.Second,proteomic characterization of wild-type rats subjected to sciatic nerve crush was performed sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry.One month after injury,distal sciatic nerves were collected and analyzed as described above.Out of 459 identified proteins,92 showed significant differences between sciatic nerve crush and the uninjured wild-type rats used in the first study.The results suggest that young adult Charcot-Marie-Tooth-1A rats(3 months old)develop compensatory mechanisms at the level of redox balance,protein folding,myelination,and axonogenesis.These mechanisms seem insufficient to hurdle the progress of the disease.Notably,response to oxidative stress appears to be a significant feature of Charcot-Marie-Tooth-1A,potentially playing a role in the pathological process.In contrast to the first experiment,the majority of the proteins that differed from wild-type were downregulated in the sciatic nerve crush group.Functional enrichment suggested that neurogenesis,response to axon injury,and oxidative stress were important biological processes.Protein analysis revealed an imperfect repair at this time point after injury and identified several distinguishable proteins.In conclusion,we suggest that peripheral neuropathies,whether of a genetic or traumatic cause,share some common pathological pathways.This study may provide directions for better characterization of these models and/or identifying new specific therapeutic targets.

Crushing Mechanism of Spherical Tungsten Alloy Fragments Penetrate Thick Steel Plate Target

Against protection requirements for high-speed fragments on the ground weapons,we carried out the research work of crushing mechanism at different impact speeds ofφ8.7 mm spherical tungsten alloy,the penetration to 603 armor steel was completed by 20 mm ballistic gun,and the ANSYS/LS-DYNA software was used to complete the numerical calculation of the penetration.We find that there are different crushing mechanisms of spherical tungsten alloy with different speeds and low speed,the crushing mechanism of fragment is mainly controlled by overall plastic deformation,shearing stripping,and squeezing at a high pressure and a high speed.The crushing mechanism will have a spallation phenomenon in addition to the crushing mechanism under high pressure.

Multi-scale impact crushing characteristics of polymetallic sulphide ores

The effects of crushing energy, ore hardness and particle size of cassiterite polymetallic sulphide ore and lead-zinc polymetallic sulphide ore on the crushing characteristics during impact crushing were investigated by mineral liberation analyzer(MLA) and drop weight test. The results show that both ores contain pyrrhotite, sphalerite, jamesonite, gangue mica and quartz except cassiterite. Cassiterite is closely associated with sulphide and quartz to form aggregates, which are mixed with each other in the form of intergrowth or symbiotic disseminated fine grains. Cassiterite has a significant impact on ore crushing characteristics. Ore hardness is negatively correlated with the product of crushing parameters of A and b, i.e. A×b, the effect of crushing energy on crushing fineness is related to crushing parameters A and b, and the influence degree increases with the increase of A. The influence degree increases with the increase of b when crushing energy ECS is less than 1 kW·h/t, and the influence degree decreases with the increase of b when crushing energy ECS is greater than 1 kW·h/t. The impact of crushing energy on crushing fineness is greater than that of ore particle size when the crushing energy is lower;on the contrary, the impact of ore particle size on crushing fineness is greater than that of crushing energy when crushing energy is higher.

New testing methodology for the quantification of rock crushability:Compressive crushing value(CCV)

Crushing is a size reduction process that plays a key role in both mineral processing and crushing–screening plant design. Investigations on rock crushability have become an important issue in mining operations and the manufacture of industrial crusher equipment. The main objective of this research is to quantify the crushability of hard rocks based on their mineralogical and mechanical properties. For this purpose, the mineralogical, physical, and mechanical properties of various hard rocks were determined. A new compressive crushing value(CCV) testing methodology was proposed. The results obtained from CCV tests were compared with those from mineralogical inspections, rock strength as well as mechanical aggregate tests. Strong correlations were found between CCV and several rock and aggregate properties such as uniaxial compressive strength(UCS), the brittleness index(S_(20)), and aggregate impact value(AIV). Furthermore, the relationship between the mineralogical properties of the rocks and their CCVs were established. It is concluded that the proposed testing methodology is simple and highly repeatable and could be utilized as a pre-design tool in the design stage of the crushing process for rock quarries.

冠状动脉分叉病变介入治疗DK Crush技术与经典Crush技术疗效比较

目的 探讨DK Crush技术与经典Crush技术治疗冠状动脉分叉病变的临床价值。方法 选择该院2019年6月—2020年6月收治的冠状动脉分叉病变患者66例为研究对象,随机数表法均分为研究组和对照组,各33例。研究组行DK Crush技术治疗,对照组行经典Crush技术治疗。比较两组治疗效果。结果 研究组手术中造影剂总量少于对照组,PCI耗时高于对照组,球囊数量少于对照组,FKBI优于对照组,差异有统计学意义(t=6.166、7.385、10.667,χ^(2)=16.189,P<0.05)。对照组手术后5例发生急性心肌梗死,4例再次行PCI手术,与研究组比较,差异无统计学意义(χ^(2)=3.462、2.395,P>0.05)。手术后,研究组主支血管各指标与对照组比较,均差异无统计学意义(t=0.426、0.135、0.994、0.401,P>0.05);研究组分支血管中除最终对吻扩张失败率外,其余指标与对照组比较差异有统计学意义(t=6.058、3.922、4.585、4.927,P<0.05);手术后12个月,两组主支血管中各指标差异无统计学意义(t=1.999、0.280、1.020、0.088,χ^(2)=0.515,P>0.05);研究组分支血管中最小管腔直径大于对照组,直径狭窄度低于对照组,差异有统计学意义(t=6.288、23.418,P<0.05)。结论 改良后的DK Crush技术可有效提高对吻扩张的成功率,且手术后并发症少,安全性高,值得临床推广应用。

Mathematical modeling on multi-stage series crushing ratio distribu- tion based on fuzzy physical programming

Double-layer, multi-roller plate crusher is a new device, that uses a multi-stage series crushing style to break particles, with the crushing ratio distribution directly influencing the machine＇s performance. Three crushing ratios of 2.25, 2.15 and 2.01, used for fuzzy physical programming, were determined. The comparison of the optimized result between the double-layer multi-roller plate crusher and a high pressure roll grinder showed that the double-layer multi-roller plate crusher had a better performance, reducing crushing force and wear.

改良Y支架术与reverse crush支架术治疗冠状动脉分叉病变的疗效比较

目的对比改良Y支架术与reverse crush支架术治疗冠状动脉分叉病变的临床疗效。方法将65例冠状动脉分叉病变患者随机分为两组,分别行改良Y支架术(改良组)和reverse crush支架术(对照组)治疗,观察两组疗效和随访1年主要心脏不良事件发生率。结果改良组手术时间、X线曝光时间短于对照组(P均<0.01);造影剂和球囊用量少于对照组(P均<0.01),最终球囊对吻成功率更高,但无统计学差异(P>0.05);6～9个月造影随访,改良组分支血管再狭窄率低于对照组(P<0.01)。1年随访结束,对照组心脏不良事件发生率高于改良组,但无统计学差异(P>0.05)。结论改良Y支架术较reverse crush支架术操作简单、费时少,具有更低的分支再狭窄率,有减少随访1年临床心脏不良事件的趋势,推荐临床优先选用。

应用Partner支架完成Crush技术治疗冠脉分叉病变的即刻及近期随访结果

目的评价国产西罗莫司药物洗脱支架（Partner）完成Crush技术治疗冠状动脉分叉病变的安全性及有效性。方法冠状动脉造影证实为冠状动脉真性分叉病变（Medina分型为1．1．1），主支和分支均选择Partner支架完成Crush技术，术后6月进行冠状动脉造影随访。结果共30例患者入选，冠脉分叉病变31处。患者平均年龄（61．7±11．2）岁，其中男性占66．7％。31处分叉病变分布：前降支与对角支51．6％，左主干与前降支和回旋支32．3％，右冠脉左室后侧支与后降支9．7％，回旋支与钝缘支6．5％。非顺应性球囊高压扩张占58．1％，最后完成球囊对吻技术96．8％。主支和分支置人支架（1．50±0．55）枚和（1．10±0．34）枚，支架长度为（37．2±1．2）mm和（21．6±0．83）mm，支架直径为（3．27±0．51）mm和（2．76±0．48）mm。近期随访主要心血管事件（MACE）的发生率为3.3％。结论西罗莫司洗脱支架Partner完成Crush技术治疗冠脉分叉病变是安全、有效的，而且相对低的医疗费用使国产西罗莫司洗脱支架Partner在复杂病变中的应用更具有吸引力。

改良T型支架置入术与经典crush技术治疗冠状动脉分叉病变的比较研究

目的评估改良T型支架置入术与经典crush技术治疗真性冠状动脉分叉病变的安全性及有效性。方法自2008年12月至2010年1月共入选62例真性冠状动脉分叉病变患者(分支血管直径≥2.5mm),其中34例患者行经典crush治疗,28例患者行改良T型支架置入术,比较两组患者术后即刻成功率、住院期间及术后30d内的主要不良心脏事件、术后6个月支架再狭窄率。结果与经典crush组相比,改良T型支架治疗组术后分支最小管腔直径大〔(2.72±0.22)mmvs(2.39±0.30)mm,P<0.01〕,分支残余狭窄程度小〔(8.3±6.8)%vs(18.6±10.2)%,P<0.01〕,最终球囊对吻扩张成功率高(100%vs73.5%,P<0.01),支架内再狭窄率较低(5.0%vs32.0%)。两组患者术后即刻成功率无统计学差异(88.24%vs100%,P=0.12)。经典crush组有1例患者因亚急性血栓再次行PCI治疗。结论改良T型支架置入术治疗冠状动脉分叉病变是安全的,其远期有效性优于经典crush技术。

Simvastatin对大鼠坐骨神经crush损伤修复作用研究

目的探讨他汀类(statins)药物Simvastatin在大鼠坐骨神经损伤修复中的作用及可能的作用机制。方法制作SD大鼠标准坐骨神经钳夹损伤(crush)模型后,分别予Simvastatin和溶媒对照干预2周。手术前后不同时间点进行趾展功能指数测定、神经电生理学、血脂水平、血清IL-6检测和组织学评价。结果Simvastatin干预组与对照组比较,趾展功能指数在术后5d和8d显著增大(P<0.05),足趾展开速度快;2周肌肉复合动作电位幅度高,4周神经传导速度快;组织学显示有髓神经纤维数量多,髓鞘厚,排列相对整齐。各组手术前血脂水平无差异,手术后2周均有不同程度的降低,但Simvastatin干预组总胆固醇降低程度最轻,与对照组比较有显著差异(P<0.05);Simvastatin干预组手术后5d,血清IL-6水平明显低于对照组(P<0.05)。结论本研究发现,Simvastatin可能通过抑制免疫炎症反应,维持神经损伤后胆固醇的平衡,促进大鼠坐骨神经损伤的修复和再生。

血管内超声指导下改良CRUSH技术治疗左主干分叉病变的效果及安全性

目的分析血管内超声(IVUS)指导下改良CRUSH技术对左主干分叉病变的疗效及随访结果。方法回顾性分析2012年7月至2014年6月经冠状动脉造影术(CAG)确诊为左主干分叉病变患者的临床资料,共6例,均在IVUS指导下接受改良CRUSH技术治疗。治疗前后均行IVUS检查,记录术前左主干、前降支及回旋支病变最小管腔面积(MLA)、最小管腔直径(MLD)、斑块负荷(PB)及其术后即刻影像表现,观察患者住院期间及出院后主要心脏不良事件(MACE,包括死亡、非致死性心肌梗死及靶病变重建)及支架内血栓、支架内再狭窄情况。结果6例患者中,应用Reverse Crush技术1例、Step Crush技术2例、DK Crush技术3例,植入药物洗脱支架共12枚,手术成功率为100%(6/6);术后临床症状均显著缓解,未见严重并发症发生。IVUS提示,6例患者术前左主干MLA为(4.57±1.36)mm2,MLD为(2.28±0.48)mm;左前降支开口MLA为(3.89±1.66)mm2,PB为(67.20±11.87)%;左回旋支开口MLA为(4.87±0.51)mm2,PB为(64.26±5.15)%;IVUS检查左前降支MLD高于QCA检查结果(P<0.05)。随访2年,未出现MACE及支架血栓情况。结论IVUS指导下左主干分叉病变改良CRUSH技术治疗左主干分叉病变效果明显,手术成功率高,具有很好的安全性和临床中远期疗效。