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Influences of Copper Speciation on Toxicity to Microorganisms in Soils

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Biomedical and Environmental Sciences 2006年第6期19卷 409-413页

作者： shu-JUAN SUN JIAN XU, shu-gui dai XUE HAN College of Environmental Science and Engineering Nankai University Tianjin 300071 China

Objective To investigate the relationship between copper speciation and microbial features （microbial communities and copper tolerance level） in order to determine the adverse effect of different forms of Cu on microorganisms. Methods Tessier＇s sequential extraction procedure was used to qualify the different Cu forms （exchangeable, carbonate bound, Fe/Mn oxide bound, residue and organic matter bound）, and the copper tolerance level （expressed as IC50, influence concentration） was measured by the plate-count method. Results By simple correlation analysis, the ICs0 was positively correlated with the concentration of exchangeable Cu （R2=0.8204）, while weakly correlated with other forms of Cu. Conclusion The bacterial community tolerance increases in the copper-contaminated soil while sensitive bacteria decrease in the copper-contaminated soils. The exchangeable Cu exerts high toxicity to microbial communities.

关键词： Copper speciation Toxicity Microbial community

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

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Journal of Environmental Sciences 2007年第3期19卷 327-331页

作者： GAO Min-ling dai shu-gui MA Yong-min ZHANG Ping College of Environmental Science and Engineering Nankai University Tianjin 300071 China Center of Disease Control and Prevention Tianjin 300011 China

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.

关键词： sorption chlorotoluron atrazine nitrogen fertilizer competitive

Characterization of Hapten-Protein Conjugates for Immunoassay of Polycyclic Aromatic Hydrocarbons(PAHs)

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Chemical Research in Chinese Universities 2008年第6期24卷 697-700页

作者： ZHANG Yan-feng GAO Zhi-xian SUN Hong-wen dai shu-gui College of Environmental Science and Engineering Key Laboratory for Pollution Process and Environmental Criteria of Ministry of Education Nankai University Tianjin 300071 P R. China Institute of Hygiene and Environmental Medicine Tianjin 300050 P R. China

Preparation and characterization of the hapten-protein conjugates are fundamental to developing environmental immunoassays. As a hapten, 1-pyrenebutyric acid（PBA） was conjugated to the carrier protein of bovine serum albumin（BSA） or ovalbumin（OVA） by active ester method. Infrared spectra（IR） showed that PBA-BSA and PBA-OVA conjugates were successfully prepared. The number of the haptens conjugated to the carrier protein was determined by ultraviolet spectra（UV） and matrix-assisted laser desorption ionization time-of-flight mass spectrometry（MALDI-TOF-MS）. The calculated average binding ratios of PBA/BSA and PBA/OVA were 18：1 and 10：1 by UV, and 31：1 and 22：1 by MALDI-TOF-MS, respectively. Although there was a discrepancy between the results determined by the two methods, both of them were useful for the characterization of the hapten-protein conjugates. The antibody was produced against the antigen of PBA-BSA, and the affinity was tested by the double agar diffusion method The conjugates and the antibody could be used for developing a sensitive and selective immunoassay of polycyclic aromatic hydrocarbons（PAHs）.

关键词： Polycyclic aromatic hydrocarbons Hapten Conjugate Immunoassay Characterization

Finite-time stabilization of nonlocal Lipschitzian stochastic time-varying nonlinear systems with Markovian switching

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Science China(Information Sciences) 2022年第11期65卷 196-216页

作者： gui-Hua ZHAO shu-Jun LIU College of Science University of Shanghai for Science and Technology College of Mathematics Sichuan University

In this study, we investigate the stochastic finite-time stability theory and finite-time stabilization of stochastic time-varying nonlinear systems with Markovian switching in the sense of weak solutions. First,we present the stochastic finite-time stability theory under the framework of weak solutions: the existence of weak solutions and stochastic finite-time stability theorems for stochastic time-varying nonlinear systems with Markovian switching. Second, for a class of high-order stochastic nonlinear systems with Markovian switching, a finite-time stabilization controller is constructively designed, and the trivial weak solution of a closed-loop system is proven to be globally finite-time stable in probability. The effectiveness of the proposed finite-time control method is illustrated by a numerical example.

关键词： stochastic time-varying nonlinear systems Markovian switching weak solutions stochastic finite-time stability finite-time control

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Esophageal Helicobacter pylori colonization aggravates esophageal injury caused by reflux

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World Journal of Gastroenterology 2014年第42期20卷 15715-15726页

作者： Yun-Xiang Chu Wei-Hong Wang Yun dai gui-Gen Teng shu-Jun Wang Department of Gastroenterology Peking University First Hospital

AIM: To investigate esophageal Helicobacter pylori (H. pylori) colonization on esophageal injury caused by reflux and the related mechanisms.

关键词： Helicobacter pylori Esophagus Metaplasia Adenocarcinoma Animal model

Phylogenetically clustering of rhizobia by genome structure:application to unclassified Rhizobium

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Journal of Environmental Sciences 2006年第3期18卷 530-536页

作者： ZHENG Jun-fang LIU gui-rong LIU shu-lin Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Department of Microbiology Peking University Health Science Center Beijing 100083 China

Previous research reveals that the genome structures of rhizobial type strains and reference strains can reflect their phylogenetic relationships. In order to further explore the potential application of genome structure as a phylogenetic marker in rhizobial natural taxonomy, this study analyzed the genome structures of 29 unclassified nodule bacteria isolated from the root nodules of leguminous trees, Robinia sp., Dalbergia spp., and A lbizia spp. and 7 rhizobial reference strains by I-CeuI cleavage, then clustered these bacteria phylogenetically based on their genome structures and compared these clusters with those based on numerical taxonomy and 16S rDNA PCR-RFLP. Eleven phylogenetic clusters were obtained, The clusters were in large part consistent with those based on numerical taxonomy and 16S rDNA PCR-RFLP. Also there are inconsistent clusters based on the above three methods. But results are completely consistent with 16S rRNA clusters. This suggested that the genome structure clustering method can be used to lastly identify root nodule isolates and detect their phylogenetic relationships. The credibility and repeatability of the results, together with the simplicity and possibility to analyze a large number of strains in a short time of the method, indicates the broad potential application of genome structure as phylogenetic marker to categorize rhizobial isolates and should in the future facilitate biodiversity studies.

关键词： rhizobia genome structure phylogenetic analysis pulsed field gel electrophoresis I-CeuI

Selection of organic Rankine cycle working fluids in the low-temperature waste heat utilization

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Journal of Hydrodynamics 2015年第3期27卷 458-464页

作者： LI Dian-xun ZHANG shu-sheng WANG gui-hua School of Energy and Power Engineering Shandong University School of Reronautics Shandong Jiaotong University

In the current study, simulations based on the engineering equation solver （EES） software are performed to determine the suitable working fluid for the simple organic Rankine cYcle system in different temperature ranges. Under the condition of various temperatures and a constant thermal power of the flue gas, the influence of different organic working fluids on the efficiency of the subcritical organic Rankine cycle power generation system is studied, and its efficiency and other parameters are compared with those of the regenerator system. It is shown that the efficiency of the subcritical organic Rankine cycle system is the best when the parameters of the working fluid in the expander inlet are in the saturation state. And for the organic Rankine cycle, the R245fa is better than other working fluids and the efficiency of the system reaches up to 10.2% when the flammability, the toxicity, the ozone depletion, the greenhouse effect and other factors of the working fluids are considered. The R60 l a working fluid can be used for the high-temperature heat source, however, because of its high flammability, new working fluid should be investigated. Under the same condition, the efficiency of the organic Rankine cycle power generation system with an internal heat exchanger is higher than that of the simple system without the internal heat exchanger, but the efficiency is related to the properties of the working fluid and the temperature of the heat source.

关键词： Rankine cycle working fluid waste heat heat exchanger low-temperature

Denaturing Effects of Urea and Guanidine Hydrochloride on Hyperthermophilic Esterase from Aeropyrum pernix K1

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Chemical Research in Chinese Universities 2006年第2期22卷 168-172页

作者： GAO Ren-jun XIE gui-qiu ZHOU Jun FENG Yan CAO shu-gui Key Laboratory for Molecular Enzymology and Engineering the Ministry of Education School of Pharmacy Jilin University Changchun 130021 P. R. China

The changes in the activity and the conformation of the hyperthermophilic esterase derived from aerobic thermophilic Aeropyrum pernix K1 （ APE1547 ） were studied during denaturation by guanidine hydrochlofide （ GdnHC1 ） and urea. The denaturation course of APE1547 was followed by the steady-state and time resolved fluorescence methods. An increase in the denaturant concentration in the denatured system can significantly enhance the inactivation and unfolding of APE1547. The enzyme can be completely inactivated with a urea concentration of 2.7 mol/L or a GdnHCl concentration of 7.5 mol/L. The fluorescence emission maximum of the enzyme protein red shifts in magnitude to a maximum value（355 nm） when the concentration of GdnHCl is 5.1 mol/L. The experimental results indicate that APE1547 has a high resistance to urea. Unfolding of APE1547 in GdnHCI（4. 2-6.0 mol/L） was shown to be an irreversible process. The present results indicate that the ion pairs in this protein may be a key factor for the stability of this esterase.

关键词： Stability Hyperthermophilic esterase Urea Guanidine hydrochloride

Effect of Calcium Cation on Thermophilic Acylamino Acid-releasing Enzyme Ape1547 from Aeropyrum pernix K1

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Chemical Research in Chinese Universities 2009年第4期25卷 513-517页

作者： ZHOU Jun XIE gui-qiu CAO shu-gui GAO Ren-jun Key Laboratory for Molecular Enzymology and Engineering Ministry of Education School of Pharmaceutical Sciences Jilin University Changchun 130021 P. R. China

The gene of enzyme（Ape1547） was cloned from hyperthermophilic archaeon Aeropyrum pernix K1 and expressed in Escherichia *** effect of calcium cation on the properties of Ape1547 was ***1547 exhibits both peptidase activity and esterase *** fluorescence spectrum shows that calcium cation quenches the fluorescence of the enzyme through static quenching mechanism,indicating that calcium cation was bound to the *** on the study of calcium cation on CD ellipticity of Ape1547 by circular dichroism,we concluded that the change of enzyme structure induced by calcium cation may be responsible for the change of enzyme *** cation has dual effects on Ape1547：it could activate the enzyme activity when its concentration was 0.1 mol/L,and the enzyme had the highest activity;however,when its concentration was higher than 0.2 mol/L,the enzyme activity was *** results indicate that the activity center of peptidase activity might involve more amino acid residues than that of esterase activity.

关键词： Acylamino acid-releasing enzyme Aeropyrum pernix K1 Conformational change Calcium cation