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Overexpression of AHL20 Negatively Regulates Defenses in Arabidopsis

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Journal of Integrative Plant Biology 2010年第9期52卷 801-808页

作者： Haibin Lu Yan ZOU na feng College of Life Sciences Peking University Beijing 100875 China national Institute of Biological Sciences Beijing 102206 China

Plants are equipped to recognize invading pathogenic microbes and activate innate immune responses by sensing pathogen-associated molecular patterns （PAMPs）. PAMP-triggered immunity （PTI） is critical for plant resistance to potential pathogens. Although the mechanism by which PTI is activated has been intensively studied, exactly how plants prevent unregulated immune responses is less well understood. Here we provide evidence that AHL20, an AT-hook containing Dna-binding protein, negatively regulates PTI. Overexpression of AHL20 as a stable transgene suppressed PAMP-induced NH01 and FRK1 expression in Arabidopsis plants. Similarly, transient expression of the closely related family members AHL19, AHL15, and AHL27 in protoplasts also blocked PAMP-induced gene expression. The AHL20 overexpression plants displayed greater susceptibility to virulent Pseudomonas syringae bacteria. These results indicate that AHL proteins play an important role in plant immunity.

关键词： PLANTS BACTERIA PATHOGENIC microorganisms Dna-binding proteins TRANSGENES ARABIDOPSIS

An Extension Landau-Lifshitz Model in Studying Soft Ferromagnetic Films

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Acta Mathematicae Applicatae Sinica 2007年第3期23卷 421-432页

作者： Jing-na Li Xiao-feng Wang Zheng-an Yao Department of Mathematics Sun Yat-sen University Guangzhou 510275 China

In this paper, we propose a model in studying soft ferromagnetic films, which is readily accessible experimentally. By using penalty approximation and compensated compactness, we prove that the dynamical equation in t... 详细信息

关键词： Landau-Lifshitz equation thin film, penalty approximation, compensated compactness

Silica-supported Macroporous Chitosan Bead for Affinity Purification of Trypsin Inhibitor

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Chinese Chemical Letters 2005年第8期16卷 1089-1092页

作者： feng na XI Jian Min WU Ming Ming LUAN Department of Chemistry Zhejiang University Hangzhou 310027

Macroporous cross-linking chitosan layer coated on silica gel （CTS-SiO2） was prepared by phase inversion and polyethylene glycol （PEG）molecular imprinting methods. Formation of macroporous surtace was investigated by scanning electron microscopy （SEM） and BET *** prepared bead was activated by reacting with 1,2-ethylene digiycidyl ether for introducing epoxy groups, and trypsin could be efficiently immobilized on the bead as a biospecific *** bead bearing trypsin was employed to purify trypsin inhibitor （TIs） from egg white as affinity adsorbent.

关键词： Chitosan silica trypsin inhibitor trypsin affinity purification.

Analysis and Prediction of Hole Penetrated in Thin Plates under Hypervelocity Impacts of Cylindrical Projectiles

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Acta Mechanica Solida Sinica 2023年第5期36卷 702-709页

作者： na feng Mingrui Li Kun Ma Chunlin Chen Lixin Yin Gang Zhou Chengwen Tan School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Northwest Institute of Nuclear Technology Xi’an 710024China

The hole penetrated in thin metallic plates due to hypervelocity impacts of cylindrical projectiles was analyzed by experimental *** projectile caused a hole-expanding effect when penetrating the target plate because of dynamic shear failure and extrusion.A new empirical model was presented to predict the perforation diameter in thin plates impacted by high-velocity cylindrical *** fitting coefficients resulted in a root-mean-square of 0.0641 and a correlation coefficient of *** errors between the predicted and the experimental values were less than 7.251%,and less than 4.705%for 93.333%cases of the *** accuracy of the proposed model is much higher than that of Hill's *** with historical equations,the new model is more accurate and can well describe the variations of different parameters with the normalized penetrated *** model takes into account the strength of materials,which contributes to the excellent *** paper could provide important theoretical support for the analysis of the perforation process and its mechanism.

关键词： Hypervelocity impact Cylindrical projectile Perforation diameter Empirical model dh Diameter of penetrated hole in the target

Exercise training attenuates angiotensinⅡ-induced cardiac fibrosis by reducing POU2F1 expression

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Journal of Sport and Health Science 2023年第4期12卷 464-476页

作者： na feng Haiyi Yu Yueshen Wang Youyi Zhang Han Xiao Wei Gao Department of Cardiology and Institute of Vascular Medicine Peking University Third HospitalNational Health Commission Key Laboratory of Cardiovascular Molecular Biology and Regulatory PeptidesKey Laboratory of Molecular Cardiovascular ScienceMinistry of EducationBeijing Key Laboratory of Cardiovascular Receptors ResearchBeijing 100191China Research Unit of Medical Science Research Management/Basic and Clinical Research of Metabolic Cardiovascular Diseases Chinese Academy of Medical SciencesBeijing 100191China

Background:Exercise training protects against heart ***,the mechanism underlying the protective effect of exercise training on angiotensinⅡ(AngⅡ)-induced cardiac fibrosis remains ***:An exercise model involving C57BL/6N mice and 6 weeks of treadmill training was ***Ⅱ(1.44 mg/kg/day)was administered to induce cardiac *** sequencing and bioinformatic analysis were used to identify the key factors mediating the effects of exercise training on cardiac *** adult mouse cardiac fibroblasts(CFs)were used in ***-associated virus serotype 9 was used to overexpress POU domain,class 2,transcription factor 1(POU2F1)in ***:Exercise training attenuated AngⅡ-induced cardiac fibrosis and reversed 39 gene expression *** transcription factor regulating the largest number of these genes was *** to controls,POU2F1 was shown to be signififcantly upregulated by AngⅡ,which is itself reduced by exercise *** vivo,POU2F1 overexpression nullified the benefits of exercise training on cardiac *** CFs,POU2F1 promoted cardiac *** enhancer-binding proteinβ(C/EBPβ)was predicted to be the transcription factor of POU2F1and verified using a dual-luciferase reporter *** vivo,exercise training activated AMP-activated protein kinase(AMPK)and alleviated the increase in C/EBPβinduced by AngⅡ.In CFs,AMPK agonist inhibited the increase in C/EBPβand POU2F1 induced by Ang II,whereas AMPK inhibitor reversed this ***:Exercise training attenuates AngⅡ-induced cardiac fibrosis by reducing *** training inhibits POU2F1 by activating AMPK,which is followed by the downregulation of C/EBPβ,the transcription factor of POU2F1.

关键词： AMPK C/EBPβ Cardiac fibrosis Exercise POU2F1

Aluminum matrix composites reinforced by molybdenum-coated carbon nanotubes

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 695-702页

作者： Jun-hui Nie Cheng-chang Jia na Shi Ya-feng Zhang Yi Li XianJia School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

To extend the application of carbon nanotubes （CNTs） and explore novel aluminum matrix composites,CNTs were coated by molybdenum layers using metal organic chemical vapor deposition,and then Mo-coated CNT （Mo-CNT）/Al composites were prepared by the combination processes of powder mixing and spark plasma *** influences of powder mixing and Mo-CNT content on the mechanical properties and electrical conductivity of the composites were *** results show that magnetic stirring is better than mechanical milling for mixing the Mo-CNTs and Al *** electrical conductivity of the composites decreases with increasing Mo-CNT *** the Mo-CNT content is 0.5wt%,the tensile strength and hardness of Mo-CNT/Al reach their maximum *** tensile strength of 0.5wt% Mo-CNT/Al increases by 29.9%,while the electrical conductivity only decreases by 7.1%,relative to sintered pure *** phase analysis of Mo-CNT/Al composites reveals that there is no formation of Al carbide in the composites.

关键词： carbon nanotubes aluminum matrix composites molybdenum layer mechanical properties electrical conductivity

Reagentless biosensor based on layer-by-layer assembly of functional multiwall carbon nanotubes and enzyme-mediator biocomposite

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第6期12卷 468-476页

作者： Xing-hua ZHOU feng-na XI Yi-ming ZHANG Xian-fu LIN Department of Chemistry Zhejiang University Hangzhou 310027 China

A simple and controllable layer-by-layer （LBL） assembly method was proposed for the construction of reagentless biosensors based on electrostatic interaction between functional multiwall carbon nanotubes （MWNTs） and enzyme-mediator biocomposites. The carboxylated MWNTs were wrapped with polycations poly（allylamine hydrochloride）（PAH） and the resulting PAH-MWNTs were well dispersed and positively charged. As a water-soluble dye methylene blue （MB） could mix well with horseradish peroxidase （HRP） to form a biocompatible and negativelycharged HRP-MB biocomposite. A （PAH-MWNTs/HRP-MB）, bionanomultilayer was then prepared by electrostatic LBL assembly of PAH-MWNTs and HRP-MB on a polyelectrolyte precursor film-modified Au electrode. Due to the excellent biocompatibility of HRP-MB biocomposite and the uniform LBL assembly, the immobilized HRP could retain its natural bioactivity and MB could efficiently shuttle electrons between HRP and the electrode. The incorporation of MWNTs in the bionanomultilayer enhanced the surface coverage concentration of the electroactive enzyme and increased the catalytic current response of the electrode. The proposed biosensor displayed a fast response （2 s） to hydrogen peroxide with a low detection limit of 2.0× 10^-7 mol/L （S/N=3）. This work provided a versatile platform in the further development of reagentless biosensors.

关键词： Reagentless biosensor Layer-by-layer assembl Horseradish peroxidase-methylene blue (HRP-MB) biocomposite Functional multiwall carbon nanotubes Hydrogen peroxide

Effect of microalloying on wettability and interface characteristics of Zr-based bulk metallic glasses with W substrate

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China Foundry 2024年第4期21卷 352-359页

作者： Zhen Zhang Lin-na feng Jin-he Wang Zheng-kun Li Hua-meng Fu Hong Li Zheng-wang Zhu Hai-feng Zhang School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Metallurgy Northeastern UniversityShenyang 110004China

The infiltration casting method is widely employed for the preparation of ex-situ composite ***,the production of composite materials using this method must necessitates a comprehensive understanding of the wettability and interface characteristics between the reinforcing phase and the bulk metallic glasses(BMGs).This work optimized the composition of Zr-based BMGs through microalloying methods,resulting in a new set of Zr-based BMGs with excellent glass-forming *** experiments between the Zr-based BMGs melts and W substrates were conducted using the traditional sessile drop method,and the interfaces were characterized utilizing a scanning electron microscope(SEM)equipped with energy dispersive X-ray spectroscopy(EDS).The work demonstrates that the microalloying method substantially enhances the wettability of the Zr-based BMGs ***,the incorporation of Nb element impedes the formation of W-Zr phases,but the introduction of Nb element does not alter the extent of interdiffusion between the constituent elements of the amorphous matrix and W element,indicating that the influence of Nb element on the diffusion of individual elements is minute.

关键词： Zr-based BMGs infiltration casting method wettability interface characteristics W-Zr phases

Study of the axial density/impedance gradient composite long rod hypervelocity penetration into a four-layer Q345 target

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Defence Technology（防务技术） 2023年第10期28卷 314-329页

作者： na feng Kun Ma Chunlin Chen Lixin Yin Mingrui Li Zhihua Nie Gang Zhou Chengwen Tan School of Materials Science and Engineering Beijing Institute of TechnologyBeijing100081PR China Laboratory of Intense Dynamic Loading and Effect Northwest Institute of Nuclear TechnologyXi'anShaanxi 710024PR China

Based on the dynamic shock response of the material and structure,the hypervelocity impact processes and mechanisms of long composite rods with axial density/impedance gradients penetration into fourlayer targets were studied through experiments and numerical simulation *** propagation law of the shock waves,together with the structural responses of the projectiles and targets,the formation and evolution of the fragment groups formed during the processes and their distributions were *** damage of each target plate was quantitatively analysed by comparing the results of the experiment and numerical *** results showed that the axial density/impedance gradient projectiles could decrease the impact pressure to a certain extent,and the degree of damage to the target plate decreased layer by layer when the head density/impedance of the projectile was *** the head density/impedance of the projectile was low,the degree of target damage first increased layer by layer until the projectile was completely eroded and then it *** results can provide a reference for the design and application of long rods with axial composite structure for velocities ranging from 6 to 10 Ma or greater.

关键词： Hypervelocity Density/impedance gradient Axial composite rod Penetration mechanism