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Early stage toxicity of excess copper to photosystem II of Chlorella pyrenoidosa–OJIP chlorophyll a fluorescence analysis

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Journal of Environmental Sciences 2009年第11期21卷 1569-1574页

作者： xia Jianrong tian Qiran School of Environmental Science and Engineering Guangzhou University Guangzhou 510006 China Marine Biology Institute Shantou University Shantou Guangdong 515063 China

Acute toxicity of excess Cu on the photosynthetic performance of Chlorella pyrenoidosa was examined by using chlorophyll a fluorescence transients and JIP-test after exposure to elevated Cu concentrations for a short time period. High Cu concentration resulted in a significant suppression in photosynthesis and respiration. The absorption flux （ABS/RC） per PSII reaction center increased with increasing Cu concentration, but the electron transport flux （ET0/RC） decreased. Excess Cu had an insignificant effect on the trapping flux （TR0/RC）. The decline in the efficiency, with which a trapped exciton can move an electron into the electron transport chain further than QA-（Ψ0）, the maximal quantum yield of primary photochemistry （φP0）, and the quantum yield of electron transport （φE0） were also observed. The amount of active PSII reaction centers per excited cross section （RC/CS） was also in consistency with the change of photosynthesis when cells were exposed to excess Cu concentration. JIP-test parameters had a good linear relationship with photosynthetic O2 evolution. These results suggested that the decrease of photosynthesis in exposure to excess Cu may be a result of the inactivation of PSII reaction centers and the inhibition of electron transport in the acceptor side.

关键词： Chlorella pyrenoidosa chlorophyll a fluorescence Cu PSII

Effect of Zn application methods on Zn distribution and bioavailability in wheat pearling fractions of two wheat genotypes

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Journal of Integrative Agriculture 2017年第7期16卷 1617-1623页

作者： LI Meng tian xiao-hong LI Xiu-li WANG Shao-xia Engineering Research Center of Eco-environment in Three Gorges Reservoir Region Ministry of Education/College of Hydraulic&Environmental Engineering China Three Gorges University Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of Agriculture/College of Natural Resources and Environment Northwest A&F University

Pearling is an effective method for evaluating the distribution of chemical components in wheat grain. Five pearling fractions （representing approximately 20% of the original sample weight） of wheat grain were obtained using the JNMJ3 rice polisher for two cultivars with different methods of Zinc （Zn） application; the residual portion （approximately 80%） was ground as flour. Results showed that folJar or soil＋foliar Zn application methods effectively increased Zn concentrations and bioavailability in whole grain and pearling fractions, but soil Zn application was ineffective in field conditions. In addition, the concentrations of Zn, Fe, Mn and Cu within wheat grain showed a diminishing trend from the outer layer to the inner portions of the wheat grain as the pearling level increased. These results cleady showed the distribution of minerals in wheat grain, especially in the outer part of the grain （bran）. The results also suggest that precise milling techniques combined with foliar Zn ap- plication could improve the Zn and Fe nutritional qualities of consumed flour and mitigate human Zn and Fe deficiencies.

关键词： Zinc (Zn) Zn bioavailability wheat grain pearling fraction

Anomaly detection of user behavior based on DTMC with states of variable-length sequences

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The Journal of China Universities of Posts and Telecommunications 2011年第6期18卷 106-115页

作者： xiao Xi xia Shu-tao tian Xin-guang ZHAI Qi-bin Graduate School at Shenzhen Tsinghua University Shenzhen 518055 China State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Network Science and Technology Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

In anomaly detection, a challenge is how to model a user＇s dynamic behavior. Many previous works represent the user behavior based on fixed-length models. To overcome their shortcoming, we propose a novel method based on discrete-time Markov chains （DTMC） with states of variable-length sequences. The method firstly generates multiple shell command streams of different lengths and combines them into the library of general sequences. Then the states are defined according to variable-length behavioral patterns of a valid user, which improves the precision and adaptability of user profiling. Subsequently the transition probability matrix is created. In order to reduce computational complexity, the classification values are determined only by the transition probabilities, then smoothed with sliding windows, and finally used to discriminate between normal and abnormal behavior. Two empirical evaluations on datasets from Purdue University and AT＆T Shannon Lab show that the proposed method can achieve higher detection accuracy and require less memory than the other traditional methods.

关键词： intrusion detection anomaly detection shell command discrete-time Markov chain (DTMC)

Upconversion nanoparticle mediated optogenetics for targeted deep brain stimulation

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Science Bulletin 2018年第7期63卷 405-407页

作者： tian xia Division of Nano Medicine Department of Medicine California Nano Systems Institute University of California Los Angeles Translational Medical Center for Zhengzhou Central Hospital Zhengzhou University Key Laboratory of Environmental Nanotechnology and Health Effects Research Center for Eco-Environmental Sciences Chinese Academy of Sciences

Brain is often called the last frontier in science[1].It is such an important organ that controls our mind and behavior,yet we know so little about *** gel-like tissue is probably the most complicated object in the universe because it contains about 100 billion nerve cells,equal to the number of stars in our galaxy,the Milky *** neuron is connected to thousands of other nerve cells by up to 40,000 individual connections called synapses。

关键词：大脑指向神经原房间连接

近红外光谱法快速测定烤烟中钙、镁、铁、锰和锌的含量

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贵州农业科学 2007年第1期35卷 28-31页

作者：周淑平程贵敏李卫红田晓霞贵州省烟草科学研究所贵州贵阳550003

运用傅立叶变换近红外漫反射光谱仪(NIRS)对初烤烟叶部分无机元素含量进行检测研究。通过应用化学计量学方法,建立了近红外光谱与初烤烟叶中钙、镁、铁、锰、锌5种无机元素含量间关系的数学模型。结果表明:钙、镁模型稳定性好,NIRS法测... 详细信息

运用傅立叶变换近红外漫反射光谱仪(NIRS)对初烤烟叶部分无机元素含量进行检测研究。通过应用化学计量学方法,建立了近红外光谱与初烤烟叶中钙、镁、铁、锰、锌5种无机元素含量间关系的数学模型。结果表明:钙、镁模型稳定性好,NIRS法测定的结果与化学方法测试结果相吻合,已具有实用性;铁、锰、锌模型也可用来快速预测初烤烟叶样品中的铁、锰、锌含量趋势,但模型精度还有待提高。

关键词：近红外光谱烤烟化学成分

肝硬化患者血浆胰岛素样生长因子结合蛋白1、3的变化及其意义

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山西医科大学学报 2007年第4期38卷 302-304,332页

作者：刘立新田小霞郭晓红韩德五山西医科大学第一临床医学院科研实验中心山西医科大学肝病研究所

目的研究胰岛素样生长因子结合蛋白(IGFBP)1、3在肝硬化患者中的变化及其意义。方法收集33例肝硬化患者和6名健康人的外周静脉血,采用双抗体夹心ELISA法检测血浆中IGFBP1、3和TGF-β1的水平;同时采用鲎试验三肽基质显色法测定血浆内毒... 详细信息

目的研究胰岛素样生长因子结合蛋白(IGFBP)1、3在肝硬化患者中的变化及其意义。方法收集33例肝硬化患者和6名健康人的外周静脉血,采用双抗体夹心ELISA法检测血浆中IGFBP1、3和TGF-β1的水平;同时采用鲎试验三肽基质显色法测定血浆内毒素的水平;采用全自动生化分析仪常规方法测定肝脏生化指标。结果肝硬化患者血浆IGF-BP1、TGF-β1和内毒素水平与健康人相比明显增高[肝硬化患者与健康人分别为(10985.37±8374.01)ng/mlvs(3360.63±829.13)ng/ml,P0.05;(8.62±9.29)U/Lvs(5.30±1.00)U/L,P>0.05]。结论IGFBP1、3在肝硬化的发生发展中可能起重要作用。肝硬化患者血浆IGFBP3水平的降低可能与TGF-β1、内毒素水平增高有关。

关键词：肝硬化胰岛素样生长因子结合蛋白质类肿瘤坏死因子β1 内毒素

Critical role of immunogenic cell death in cancer therapy

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Science Bulletin 2017年第21期62卷 1427-1429页

作者： tian xia division of nanomedicine department of medicineuniversity of california los angelesCA 90095USA center for environmental implications of nanotechnology(cein) california nano systems institute(cnsi)university of californiaCA 90095USA state key laboratory of environmental chemistry and ecotoxicology research center for eco-environmental scienceschinese academy of sciencesBejing 100085China

In traditional cancer therapy, including chemo and radiation therapy, the goal is always to kill as much cancer cells as possible. However, the truth is that it is difficult to kill 100% of the cancer cells for these therapies and the remaining cells often leads to relapse. So the million-dollar question is, how to eliminate the majority of the remaining cancer cells so that the disease can be manageable in a clinical setting. Currently the best approach that is attracting much attention is cancer immune therapy and excit- ing developments in this field have led to cure in some cases that is unimaginable before [1]. There are two major parts to cancer immune therapy that need to work together to make the therapy successful. One is on the reversal of immune suppressive microen- vironment in cancer to allow the immune cells to target the tumor.

关键词： Critical role of immunogenic cell death cancer therapy

ON HERMItian POSITIVE DEFINITE SOLUTION OF NONLINEAR MATRIX EQUATION X＋A^＊X^-2A=Q

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Journal of Computational Mathematics 2005年第5期23卷 513-526页

作者： xiao xia Guo ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080

Based on the fixed-point theory, we study the existence and the uniqueness of the maximal Hermitian positive definite solution of the nonlinear matrix equation X＋A^＊X^-2A=Q, where Q is a square Hermitian positive definite matrix and A＊ is the conjugate transpose of the matrix A. We also demonstrate some essential properties and analyze the sensitivity of this solution. In addition, we derive computable error bounds about the approximations to the maximal Hermitian positive definite solution of the nonlinear matrix equation X＋A^＊X^-2A=Q. At last, we further generalize these results to the nonlinear matrix equation X＋A^＊X^-nA=Q, where n≥2 is a given positive integer.

关键词： Nonlinear matrix equation Hermitian positive definite solution Sensitivity analysis Error bound

Research on Patch Near-field Acoustic Holography Based on HELS Algorithm

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Journal of Harbin Institute of Technology(New Series) 2014年第5期21卷 91-95页

作者： xiao-xia Guo Chao-Feng Lan tian-He Yu Institute of Electrical and Electronics Engineering Harbin University of Science and Technology

A Patch NAH method based on HELS( helmholtz equation least-squares) algorithm is proposed for the measurement requirement of underwater large structures. This method chooses HELS algorithm to approximate the sound field completely,and calculates the sound field data outside the measurement region to enlarge the measurement aperture. It can reconstruct the sound field by the measurement data and the extrapolation data,through the reconstruction result it can be researched for the minimum measurement surface and the range of the extrapolation data in application. The paper analyzes the effect from the different measurement surfaces and different extrapolation ranges to the extrapolation data by simulations,and compares these reconstructed results with the conventional algorithm results. The simulation results indicate that the method can simplify the holographic measuring system,save the cost of the project and improve the accuracy of the sound field reconstruction,which can be effectively used for measuring and analyzing the underwater large structures.

关键词： PNAH HELS Minimum measuring surface Extrapolation range