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南方根结线虫生防菌X-20的鉴定及其作用机制研究

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中国生物防治学报 2024年第1期40卷 196-205页

作者：董海龙路平翟浩臻赵增旗王莉王建明徐玉梅山西农业大学植物保护学院晋中030801 新西兰土地环境保护研究所奥克兰1072 山西省植物保护植物检疫中心太原030001

南方根结线虫是设施蔬菜上的重要植物病原物,但目前缺乏安全高效的生物防治措施。本研究从根结线虫罹病土壤中分离到一株生防菌X-20,其发酵液对南方根结线虫二龄幼虫校正死亡率达100%。通过形态学、生理生化特征和分子生物学方法将菌株X... 详细信息

南方根结线虫是设施蔬菜上的重要植物病原物,但目前缺乏安全高效的生物防治措施。本研究从根结线虫罹病土壤中分离到一株生防菌X-20,其发酵液对南方根结线虫二龄幼虫校正死亡率达100%。通过形态学、生理生化特征和分子生物学方法将菌株X-20鉴定为荧光假单胞菌Pseudomonas fluorescens。菌株X-20发酵液处理南方根结线虫时,当处理浓度1 mg/mL,虫体出现扭曲、僵直变化,内部组织分解;处理1 h后,虫体波动频率降幅47.26%、头部摆动频率波动性变化、虫体弯曲频率成s型变化;处理24 h后,二龄幼虫的体长减少4.68%,口针增加7.64%,透明尾长增加83.90%;j2虫体体液出现外渗,且电导率随着处理浓度的增大和时间延长而增加;发酵液甲醇提取物1mg/mL处理虫体,6h后糖含量比对照增加39.10%,甘油含量比对照高出66.67%,可溶性蛋白含量降低55.73%。由此可见,荧光假单胞菌X-20菌株代谢产物通过破坏根结线虫体壁及虫体内部结构,引起虫体液渗漏,扰乱虫体内糖类、脂类、蛋白类代谢,造成虫体死亡。

关键词：荧光假单胞菌代谢产物南方根结线虫防治效果生防机理

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Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys with adjusting Y addition

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journal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： j.A.Liu s.j.Liu b.wang w.b.sun X.j.Liu Z.w.Han College of Materials science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China weihai Institute for bionics-jilin University Weihai 264205PR China

In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption *** characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),w-phase(Mg_(3)Zn_(3)Y_(2)),and LPsO phase(Mg_(12)ZnY).when the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 Mj/m^(3)to 10.97 Mj/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.jeong s.w.Lee w.j.Kim Department of Materials science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the bCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy superplasticity severe plastic deformation Grain size Grain growth

Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

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journal of Materials science & Technology 2024年第2期169卷 53-67页

作者： Y.b.Zhang s.j.song F.Liu state Key Laboratory of solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3D CPFE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).by detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic *** by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

由超拍电子伏特加速器产生的超高能伽马射线气泡

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science bulletin 2024年第4期69卷 449-457页

作者： LHAAsO Collaboration Zhen Cao Chuandong Gao Cong Li Ruo-Yu Liu Ruizhi Yang 不详 Key Laboratory of Particle Astrophyics&Experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of sciences Beijing 100049China TIANFU Cosmic Ray Research Center ChengduChina Institute of Frontier and Interdisciplinary science Shandong UniversityQingdao 266237China school of Astronomy and space science Nanjing UniversityNanjing 210023China University of science and Technology of China Hefei 230026China

we report the detection of aγ-ray bubble spanning at least 100deg2 in ultra-high energy(UHE)up to a few PeV in the direction of the star-forming region Cygnus X,implying the presence super PeVatron(s)accelerating protons to at least 10 PeV.A log-parabola form with the photon indexΓ(E)=(2.71±0.02)+(0.11±0.02)×log10(E/10 TeV)is found fitting the gamma-ray energy spectrum of the bubble *** sources,“hot spots”correlated with very massive molecular clouds,and a quasi-spherical amorphousγ-ray emitter with a sharp central brightening are observed in the *** the core of~0.5°,spatially associating with a region containing massive Ob association(Cygnus Ob2)and a microquasar(Cygnus X-3),as well as previously reported multi-TeV sources,an enhanced concentration of UHEγ-rays is observed with 2 photons at energies above 1 *** general feature of the bubble,the morphology,and the energy spectrum,are reasonably reproduced by the assumption of a particle accelerator in the core,continuously injecting protons into the ambient medium.

关键词： Cosmic rays γ-rays Interstellar medium star cluster

Inflow and outflow permeability tests in a very soft clay under low stresses

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journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： j.w.s.Vargas F.A.b.Danziger F.R.Lopes T.Lunne Federal University of Rio de janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the bAT probe at sarapuíII soft clay test site are presented.A description of the bAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for sarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test soft clay bAT probe Inflow and outflow tests

工业试验Mg脱氧HsLA钢CGHAZ的夹杂物、组织及韧性的特征分析

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炼钢 2024年第2期40卷 89-94页

作者：杜海龙张银辉杨健张宇张玉旗上海大学材料科学与工程学院省部共建高品质特殊钢冶金与制备国家重点实验室上海200444 张家港荣盛特钢有限公司江苏张家港215625

Mg作为第三代氧化物冶金技术的关键脱氧剂有助于提升高强度低合金钢(HsLA)的组织韧性。利用夹杂物自动分析系统、金相显微镜、焊接热模拟试验机等研究了Mg脱氧对HsLA钢粗晶热影响区(CGHAZ)夹杂物、组织以及低温冲击韧性的影响。结果表明... 详细信息

Mg作为第三代氧化物冶金技术的关键脱氧剂有助于提升高强度低合金钢(HsLA)的组织韧性。利用夹杂物自动分析系统、金相显微镜、焊接热模拟试验机等研究了Mg脱氧对HsLA钢粗晶热影响区(CGHAZ)夹杂物、组织以及低温冲击韧性的影响。结果表明,在200 kj/cm的大线能量焊接条件下,Mg脱氧钢CGHAZ中生成了大量Mg-Ti-Mn-s夹杂物,由于这种类型的夹杂物可以促进针状铁素体(IAF)组织的形成,所以在200 kj/cm大线能量焊接后,Mg脱氧钢CGHAZ低温冲击韧性优异,-20℃冲击功为204 j,断裂方式为韧性断裂。本研究成果可为提高大线能量焊接厚板钢组织性能提供理论与试验依据。

关键词： HsLA钢 Mg脱氧大线能量焊接焊接热影响区低温冲击韧性

The CCD instrument background of the sMILE sXI

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Earth and Planetary Physics 2024年第1期8卷 15-24页

作者： M.w.j.Hubbard O.Hetherington D.j.Hall T.w.buggey s.Parsons T.Arnold A.Holland C.Pagani s.sembay Centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

The EsA and CAs sMILE mission orbit is highly elliptical and will pass through multiple radiation *** soft X-ray Imager(sXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is *** shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen ***,two radiation environments can be approximated based on the shutter door position:open and *** instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the sXI were evaluated for the two *** to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two *** results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar *** is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation

探讨黄芪甲苷调控细胞焦亡减轻肠缺血再灌注损伤的分子作用机制

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中国实验方剂学杂志 2024年

作者：常利娅冷玉芳赵紫岑王玉邢阳李东斌兰州大学第一医院兰州大学第一临床医学院

目的:采用网络药理学和体内实验结合的方法研究黄芪甲苷(As-Ⅳ)调控细胞焦亡(Pyroptosis)减轻肠缺血再灌注损伤(IRI)的作用机制。方法:首先从中药系统药理数据库和分析平台(TCMsP)数据库和swiss Target Prediction数据库中检索获得As-... 详细信息

目的:采用网络药理学和体内实验结合的方法研究黄芪甲苷(As-Ⅳ)调控细胞焦亡(Pyroptosis)减轻肠缺血再灌注损伤(IRI)的作用机制。方法:首先从中药系统药理数据库和分析平台(TCMsP)数据库和swiss Target Prediction数据库中检索获得As-Ⅳ的对应靶点基因，并从GeneCards数据库中检索得到肠IRI和Pyroptosis相关的靶点基因，通过解螺旋网站绘制Venn图，获得三者的共同靶点基因。通过sTRING数据库和Cytoscape软件构建蛋白-蛋白相互作用(PPI)网络筛选共同靶基因并导入Cytoscape软件获得核心靶基因。微生信平台用于基因本体(GO)和京都基因与基因组百科全书(KEGG)富集分析并预测As-Ⅳ调控Pyroptosis减轻肠IRI的作用机制。然后采用随机数字表法，将C57/bL6j小鼠随机分为5组，正常组、模型组(IR)、给药组(IR+ As-Ⅳ)、核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)激动剂Nss组(IR+ As-Ⅳ+Nss)、NLRP3抑制剂MCC950组(IR+ As-Ⅳ+MCC950)。模型组、给药组、NLRP3激动剂Nss组、NLRP3抑制剂MCC950组采用夹闭肠系膜上动脉45 min恢复灌注2 h建立肠IRI模型，正常组仅分离血管不夹闭。给药组、NLRP3激动剂Nss组、NLRP3抑制剂MCC950组于造模前连续3天灌胃溶于0.1%二甲基亚砜的黄芪甲苷(50 mg·kg-1)，末次灌胃时间为造模前2 h，其余两组灌胃等量的生理盐水。NLRP3激动剂Nss组于造模前1 h腹腔注射4 mg·kg-1的Nss，NLRP3抑制剂MCC950组于造模前1 h腹腔注射10 mg·kg-1的MCC950。再灌注2 h处死小鼠，获取肠组织。采用美联免疫吸附测定法(ELIsA)检测白细胞介素(IL)-18，IL-1β水平，蛋白免疫印迹法(western blot)检测硫氧还蛋白结合蛋白(TXNIP)、NLRP3、胱天蛋白酶(Caspase)-1、焦孔素D(GsDMD)蛋白表达，Chiu’s评分评估小鼠肠组织病理学变化。结果:网络药理学分析表明肠IRI的靶点有1599个，As-Ⅳ的作用靶点有199个，Pyroptosis的靶点有197个，三者共同靶点有20个。核心靶点有10个，包括NLRP3、TXNIP、沉默信息调节因子1(sIRT1)、高迁移率族蛋白1(HMGb1)、IL-18、GsDMD、基质金属蛋白酶-9(MMP-9)等。共同靶点的KEGG富集筛选出的通路相关性最大的是NOD样受体通路。体内实验结果表明，与正常组比较，模型组Chiu’s评分升高，小鼠肠组织IL-18，IL-1β炎症因子水平明显升高(Pspase-1、GsDMD蛋白表达水平明显升高(Ps评分降低，小鼠肠组织IL-18，IL-1β炎症因子水平降低(Pspase-1、GsDMD蛋白表达水平明显降低(Pss组Chiu’s评分升高，小鼠肠组织IL-18，IL-1β炎症因子水平明显升高(Pspase-1、GsDMD蛋白表达水平明显升高(Pss组Chiu’s评分升高，小鼠肠组织IL-18，IL-1β炎症因子水平明显升高(Pspase-1、GsDMD蛋白表达水平明显升高(P<0.05)。结论:网络药理学预测结果与体内实验结果一致，黄芪甲苷通过TXNIP/NLRP3信号通路抑制细胞焦亡减轻肠缺血再灌注损伤。

关键词：黄芪甲苷肠缺血再灌注损伤硫氧还蛋白结合蛋白(TXNIP)/核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)信号通路细胞焦亡网络药理学