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Efflux pump gene hefA of Helicobacter pylori plays an important role in multidrug resistance

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World Journal of Gastroenterology 2008年第33期14卷 5217-5222页

作者： Zhi-Qiang Liu Peng-Yuan Zheng Ping-chang yang Department of Gastroenterology the Second Affiliated Hospital of Zhengzhou University Zhengzhou 450014 Henan Province China Department of Pathology and Molecular Medicine McMaster University Hamilton Ontario L8N 4A6 Canada

AIM: To determine whether efflux systems contribute to multidrug resistance of H pylori. METHODS: A chloramphenicol-induced multidrug resistance model of six susceptible H pylori strains (5 isolates and H pylori NCTC11637) was developed. Multidrug-resistant (MDR) strains were selected and the minimal inhibitory concentration (MIC) of eryth-romycin, metronidazole, penicillin G, tetracycline, and ciprofloxacin in multidrug resistant strains and their parent strains was determined by agar dilution tests. The level of mRNA expression of hefA was assessed by fluorescence real-time quantitative PCR. A H pylori LZ1026 knockout mutant (ΔH pylori LZ1026) for (puta-tive) efflux protein was constructed by inserting the kanamycin resistance cassette from pEGFP-N2 into hefA, and its susceptibility profiles to 10 antibiotics were evaluated. RESULTS: The MIC of six multidrug-resistant strains (including 5 clinical isolates and H pylori NCTC11637) increased signifi cantly (≥ 4-fold) compared with their parent strains. The expression level of hefA gene was significantly higher in the MDR strains than in their parent strains (P = 0.033). A H pylori LZ1026 mutant was successfully constructed and the ΔH pylori LZ1026 was more susceptible to four of the 10 antibiotics. All the 20 strains displayed transcripts for hefA that con-fi rmed the in vitro expression of these ***: The efflux pump gene hefA plays an important role in multidrug resistance of H pylori.

关键词： Efflux pump Helicobacter pylori Multidrug resistance Fluorescence real-time quantitative PCR Knockout mutant

Community detection with attributed random walk via seed replacement

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Frontiers of Computer Science 2022年第5期16卷 45-56页

作者： yang chang Huifang MA Liang chang Zhixin LI College of Computer Science and Engineering Northwest Normal UniversityLanzhou 730070China Guangxi Key Lab of Multi-source Information Mining and Security Guangxi Normal UniversityGuilin 541004China Guangxi Key Laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin 541004China

Community detection methods based on random walks are widely adopted in various network analysis *** could capture structures and attributed information while alleviating the issues of *** random walks on plain networks have been studied before,in real-world networks,nodes are often not pure vertices,but own different characteristics,described by the rich set of data associated with *** node attributes contain plentiful information that often complements the network,and bring opportunities to the random-walk-based ***,node attributes make the node interactions more complicated and are heterogeneous with respect to topological ***,attributed community detection based on random walk is challenging as it requires joint modelling of graph structures and node *** bridge this gap,we propose a Community detection with Attributed random walk via Seed replacement(CAS).Our model is able to conquer the limitation of directly utilize the original network topology and ignore the attribute *** particular,the algorithm consists of four stages to better identify communities.(1)Select initial seed nodes in the network;(2)Capture the better-quality seed replacement path set;(3)Generate the structure-attribute interaction transition matrix and perform the colored random walk;(4)Utilize the parallel conductance to expand the *** on synthetic and real-world networks demonstrate the effectiveness of CAS.

关键词： community detection seeds colored random walk parallel conductance

Fabrication of microcapsule arrays on chemically patterned surfaces via covalent linking

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第1期10卷 114-120页

作者： Jie yang chang-you GAO MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China

A method for fabricating arrays of microcapsules covalently immobilized onto chemically patterned substrates was *** core-shell microparticles with poly(allylamine hydrochloride)(PAH) as the outermost layer were obtained by layer-by-layer (LbL) assembly,which were further treated with glutaraldehyde to endow the particles with abundant aldehyde groups on their *** particles were then covalently coupled to the chemically patterned regions with amino groups created by microcontact printing (μCP).After dissolution of the core particles,arrays of the hollow microcapsules with unchanged structures were *** arrays could stand rigorous environmental conditions of higher ionic strength,and lower and higher pH ***,the technique could be possibly applied to exploiting chips of microcontainers or microreactors in sensing technology.

关键词： Array Microcapsules Microcontact printing (μCP) Covalent interaction

A SING ULAR PARAM ETERIZED FINITE VOLUME METHOD FOR THE ADVECTION-DIFFUSION EQUATION IN IRREGULAR GEOMETRIES

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Journal of Computational Mathematics 2019年第5期37卷 579-608页

作者： chang yang Meng Wu Department of Mathematics Harbin Institute of TechnologyHarbin 150001China School of Mathematics Hefei University of TechnologyHefei 230026China

Solving the advection-diffusion equation in irregular geometries is of great importance for realistic simulations. To this end, we adopt multi-patch parameterizations to describe irregular geometries. Different from the classical multi-patch parameterization method, C 1- continuity is introduced in order to avoid designing interface conditions between adjacent patches. However, singularities of parameterizations can’t always be avoided. Thus, in this paper, a finite volume method is proposed based on smooth multi-patch singular parameterizations. It is called a singular parameterized finite volume method. Firstly, we present a numerical scheme for pure advection equation and pure diffusion equation respectively. Secondly, numerical stability results in L2 norm show that the numerical method is not suffered from the singularities. Thirdly, the numerical method has second order accurate in L2 norm. Finally, three numerical tests in different irregular geometries are presented to show efficiency of this numerical method.

关键词： Finite volume method Smooth multi-patch singular parameterizations The advection-diffusion equation Irregular geometries

New Discovery of Holocene Activity along the Weixi-Qiaohou Fault in Southeastern Margin of the Tibetan Plateau and its Neotectonic Significance

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Acta Geologica Sinica(English Edition) 2018年第6期92卷 2464-2465页

作者： chang Zufeng ZANG yang and chang Hao Yunnan Earthquake Agency Kunming650224China

Objective The lateral extrusion eastward of the Tibetan Plateau leads to the formation of the Sichuan–Yunnan block, which is the most representative active block in the southeastern margin of the Tibetan Plateau, characterized by strong and frequent seismicity(Li Ping et al., 1975; Zhang Peizhen et al., 2003; Li Yong et al., 2017). Its eastern boundary is composed of sinistral faults including the Xianshuihe, Xiaojiang faults, etc., and the western

关键词： New Discovery of Holocene Activity along the Weixi-Qiaohou Fault in Southeastern Margin of the Tibetan Plateau and its Neotectonic Significance

EIGEN-TEMPERATURE MODEL FOR THE ANNUAL AIR TEMPERATURE MOVEMENT EVALUATION AND FORECAST

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International Journal of Modeling, Simulation, and Scientific Computing 2013年第3期4卷 30-53页

作者： ZONG-chang yang School of Information and Electronical Engineering Hunan University of Science and Technology Xiangtan 411201 P.R.China

Climate variability and its changes are issues of broader global *** study addresses the annual air temperature movement evaluation and forecasting based on principal component analysis(PCA).An Eigen-temperature model for describing the annual air temperature movement by employing PCA is *** for evaluation is generated by selecting principal orthogonal eigenvectors of covariance matrix of temperature *** principal eigenvectors are called“Eigen-temperatures”,since they are eigenvectors and each temperature movement is described by *** temperature movement is projected onto the subspace of eigenspace,and described by a linear combination of the ***,a forecast method for the temperature movement by employing the Eigen-temperatures is *** is implemented with polynomial curve fitting algorithm to estimate subsequent representation weights for the subsequent temperature movement with respect to the“Eigen-temperatures”generated by its previous temperature *** proposed Eigen-temperature model is applied to evaluation and forecasting for annual temperature movement at Tongchuan observation station of China from 1962 to 1971 and from 1994 to *** results agreeing well with actual observation values show workability of the *** analysis indicates its effectiveness that the proposed Eigen-temperature model is outperforming the classical AR model and the BP-ANN on the forecast tasks.

关键词： Principal component analysis annual air temperature movement Eigentemperature model.

Migration of hepatic stellate cells in fibrotic microenvironment of diseased liver model

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Hepatobiliary & Pancreatic Diseases International 2008年第4期7卷 401-405页

作者： chang, Yi-Zhong yang, Li yang, chang-Qing Tongji Univ Tongji Hosp Div Gastroenterol Shanghai 200065 Peoples R China

BACKGROUND: In liver fibrosis, alterations within the space of Disse microenvironment facilitate the progression of chronic liver disease. The normal basement membranelike matrix in the space of Disse converts to a matrix rich in fibril-forming collagens during the fibrosis. This study aimed to investigate the impact of alterations in the space of Disse microenvironment on the migration of hepatic stellate cells (HSCs) in the process of liver fibrosis, and to explore the novel mechanism ofliver fibrosis from the viewpoint of cell migration. METHODS: A modified in vitro Boyden chamber system was employed to partially mimic the in vitro microenvironment of the Disse space in normal liver and in fibrosis. The effects of fibrogenetic growth factors on the migration of HSCs in simulated liver fibrosis were assessed by cell migration and cell proliferation experiments. RESULTS: Enhanced platelet-derived growth factor (PDGF)-BB, transforming growth factor-beta 1 (TGF-beta 1) and/or epithelial growth factor (EGF) in liver fibrosis resulted in an increase in migratory capacity of activated HSCs. The enhanced migration of HSCs, induced by PDGF-BB was proliferation -independent. The elevation of basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) during liver fibrosis had no effect on the migration of HSCs. CONCLUSIONS: The study provides valuable insights into the role of the space of Disse microenvironment in regulating the migratory behavior of HSCs. TGF-beta 1, PDGF-BB and EGF, which increase in liver fibrosis, induce the migration of activated HSCs. However, bFGF and VEGF have no effect although they also increase during liver fibrosis.

关键词： liver fibrosis hepatic stellate cells migration

Reduction in cadmium accumulation in japonica rice grains by CRISPR/Cas9-mediated editing of OsNRAMP5

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Journal of Integrative Agriculture 2019年第3期18卷 688-697页

作者： yang chang-hong ZHANG yang HUANG Chao-feng College of Resources and Environmental Sciences Nanjing Agricultural University Shanghai Center for Plant Stress Biology and National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant Sciences Chinese Academy of Sciences

Cadmium(Cd) intake is harmful to human health and Cd contamination in rice grains represents a severe threat to those consuming rice as a staple food. Knockout of Cd transporters is a promising strategy to reduce Cd accumulation in rice grains. OsNRAMP5 is the major transporter for Cd and manganese(Mn) uptake in rice. Nevertheless, it is uncertain whether knockout of OsNRAMP5 is applicable to produce low Cd rice without affecting plant growth and grain yield. In this study, we adopted CRISPR/Cas9-based gene editing technology to knock out OsNRAMP5 in two japonica varieties. We generated three independent transgene-free osnramp5 mutants and investigated the effect of osnramp5 mutations on Cd accumulation and plant growth. Hydroponic experiments showed that plant growth and chlorophyll content were significantly reduced in osnramp5 mutants at low Mn conditions, and this defective growth in the mutants could be fully rescued by supply of high levels of Mn. Cd and Mn accumulation in both roots and shoots was markedly reduced in the mutants compared to that in wild-type plants. In paddy field experiments, although Cd in flag leaves and grains was greatly reduced in osnramp5 mutants, some agronomic traits including plant height, seed setting rate, and grain number per panicle were affected in the mutants, which ultimately caused a mild reduction in grain yield. The reduced plant growth in the mutants can be attributed to a marked decrease in Mn accumulation. Our results reveal that the manipulation of OsNRAMP5 should be treated with caution: When assessing the applicability of osnramp5 mutants, soil pH and soil water content in paddy fields need to be taken into consideration, since they might affect the levels of available Mn in the soil and consequently determine the effect of the mutation on grain yield.

关键词： cadmium content CRISPR/Cas9 OsNRAMP5 Oryza sativa(rice)

An Extension of a Simply Inequality Between von Neumann–Jordan and James Constants in Banach Spaces

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Acta Mathematica Sinica,English Series 2017年第9期33卷 1287-1296页

作者： chang Sen yang Feng Hui WANG College of Mathematics and Information Science He'nan Normal UniversityXinxiang 453007P.R.China Department of Mathematics Luoyang Normal UniversityLuoyang 471022P.R.China

For a non-trivial Banach space X, let J（X）,CNj（X）,C（P）NJ（X） respectively stand for the James constant, the yon Neumann-Jordan constant and the generalized yon Neumann-Jordan constant receatly inroduced by Cui et al. In this paper, we discuss the relatioa between the James and the generalized yon Neumann-Jordan constants, and establish an inequality between them： C（P）NJ（X） ≤ J（X） with p 〉 2, which covers the well-known inequality CNJ（X） ≤ J（X）. We also introduce a new constant, from which we establish another inequality that extends a result of Alonso et al.

关键词： von Neumann-Jordan constant James constant inequalities