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Search Results: 1 - 10 of 197178 matches for " Xuefei Zhou Wenjing Sang Shushen Liu Yalei Zhang Huilin Ge "
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Modeling and prediction for the acute toxicity of pesticide mixtures to the freshwater luminescent bacterium Vibrio qinghaiensis sp.-Q67

Xuefei Zhou Wenjing Sang Shushen Liu Yalei Zhang Huilin Ge,

环境科学学报(英文版) , 2010,
Abstract: In China, water pollution by pesticide mixtures has constituted a serious environmental problem due to potential toxicity and bioaccumulation. But few pesticide combinations have exactly similar and dissimilar mechanisms of action. For this purpose, in tests with the freshwater luminescent bacterium (Vibrio qinghaiensis sp.-Q67), ten pesticides, including three herbicides and seven insecticides, were selected as test substances. Concentration response analysis was performed for ten individual substances, an...
Application of Molecularly Imprinted Polymers to Selective Removal of Clofibric Acid from Water
Chaomeng Dai, Juan Zhang, Yalei Zhang, Xuefei Zhou, Shuguang Liu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0078167
Abstract: A new molecularly imprinted polymer (MIP) adsorbent for clofibric acid (CA) was prepared by a non-covalent protocol. Characterization of the obtained MIP was achieved by scanning electron microscopy (SEM) and nitrogen sorption. Sorption experimental results showed that the MIP had excellent binding affinity for CA and the adsorption of CA by MIP was well described by pseudo-second-order model. Scatchard plot analysis revealed that two classes of binding sites were formed in the MIP with dissociation constants of 7.52±0.46 mg L?1 and 114±4.2 mg L?1, respectively. The selectivity of MIP demonstrated higher affinity for CA over competitive compound than that of non-imprinted polymers (NIP). The MIP synthesized was used to remove CA from spiked surface water and exhibited significant binding affinity towards CA in the presence of total dissolved solids (TDS). In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance.
Binding of Bezafibrate to Human Serum Albumin: Insight into the Non-Covalent Interaction of an Emerging Contaminant with Biomacromolecules
Yajie Qian,Xuefei Zhou,Jiabin Chen,Yalei Zhang
Molecules , 2012, DOI: 10.3390/molecules17066821
Abstract: In recent years, bezafibrate (BZF) has been frequently detected in environmental media. In order to reveal the toxicity of such an emerging pollutant, its interaction with human serum albumin (HSA) was studied by fluorescence spectrometry, circular dichroism, and equilibrium dialysis. Fluorescence data showed that the fluorescence quenching of HSA by BZF resulted from the formation of HSA-BZF complex. The binding constants were determined to be 3.33 × 103, 2.84 × 103 M?1 at 298 and 309.5 K, respectively. The thermodynamic determination indicated that the hydrophobic and electrostatic interaction were the dominant binding force. The conformational investigation showed that the presence of BZF increased the α-helix content of HSA and induced the slight unfolding of the polypeptides of protein. Finally, the equilibrium dialysis showed that 0.56 mM BZF decreased the binding of vitamin B2 to HSA by 29%.
Application of Zero-Valent Iron Nanoparticles for the Removal of Aqueous Zinc Ions under Various Experimental Conditions
Wen Liang, Chaomeng Dai, Xuefei Zhou, Yalei Zhang
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0085686
Abstract: Application of zero-valent iron nanoparticles (nZVI) for Zn2+ removal and its mechanism were discussed. It demonstrated that the uptake of Zn2+ by nZVI was efficient. With the solids concentration of 1 g/L nZVI, more than 85% of Zn2+ could be removed within 2 h. The pH value and dissolved oxygen (DO) were the important factors of Zn2+ removal by nZVI. The DO enhanced the removal efficiency of Zn2+. Under the oxygen-contained condition, oxygen corrosion gave the nZVI surface a shell of iron (oxy)hydroxide, which could show high adsorption affinity. The removal efficiency of Zn2+ increased with the increasing of the pH. Acidic condition reduced the removal efficiency of Zn2+ by nZVI because the existing H+ inhibited the formation of iron (oxy)hydroxide. Adsorption and co-precipitation were the most likely mechanism of Zn2+ removal by nZVI. The FeOOH-shell could enhance the adsorption efficiency of nZVI. The removal efficiency and selectivity of nZVI particles for Zn2+ were higher than Cd2+. Furthermore, a continuous flow reactor for engineering application of nZVI was designed and exhibited high removal efficiency for Zn2+.
Progress in microalgae culture system for biodiesel combined with reducing carbon dioxide emission
二氧化碳减排产柴油微藻培养体系研究进展

Hongyang Su,Xuefei Zhou,Xuefen Xi,Zhen Sun,Yalei Zhang,
苏鸿洋
,周雪飞,夏雪芬,孙振,张亚雷

生物工程学报 , 2011,
Abstract: Wastewater resources, CO2 emission reduction and microalgae biodiesel are considered as current frontier fields of energy and environmental researches. In this paper, we reviewed the progress in system of microalgae culture for biodiesel production by wastewater and stack gas. Multiple factors including microalgal species, nutrition, culture methods and photobioreactor, which were crucial to the cultivation of microalgae for biodiesel production, were discussed in detail. A valuable culture system of microalgae for biodiesel production or other high value products combined with the treatment of wastewater by microalgae was put forward through the optimizations of algal species and culture technology. The culture system coupled with the treatment of wastewater, the reduction of CO2 emission with the cultivation of microalgae for biodiesel production will reduce the production cost of microalgal biofuel production and the treatment cost of wastewater simultaneously. Therefore, it would be a promising technology with important environmental value, social value and economic value to combine the treatment of wastewater with the cultivation of microalgae for biodiesel production.
Influence of agent adding mode on ammonia and phosphorous removal through struvite precipitation
投药方式对鸟粪石法脱氮除磷的影响

Yang Hongrui,Zhu Hongguang,Zhou Xuefei,Zhang Yalei,
杨鸿瑞
,朱洪光,周雪飞,张亚雷

环境工程学报 , 2011,
Abstract: 鸟粪石法脱氮除磷过程中,投药方式对反应产生很大影响。以MgCl2·6H2O和Na2HPO4·12H2O为沉淀剂进行脱氮除磷的实验研究,结果表明,药剂的投加顺序影响不大,加药速度以缓慢加药为宜,pH值调节时机对氮磷的去除率影响很大,pH值调节时机由前调改为后调,氨氮的去除率由70%左右提高至80%~85%, 磷的去除率由60%左右提高至80%左右。综合比较技术经济性,认为当氨氮和磷含量较低时,可采用前调pH值,对于高氨氮和磷废水,适于后调pH值。
Assessment and Countermeasures for Offshore Wind Farm Risks Based on a Dynamic Bayesian Network  [PDF]
Chunhui Zhou, Xin Liu, Langxiong Gan, Yuanzhou Zheng, Qingyun Zhong, Kailiang Ge, Lei Zhang
Journal of Environmental Protection (JEP) , 2018, DOI: 10.4236/jep.2018.94024
Abstract: Wind power is a kind of clean energy promising significant social and environmental benefits, and in The Peoples Republic of China, the government supports and encourages the development of wind power as one element in a shift to renewable energy. In recent years however, maritime safety issues have arisen during offshore wind power construction and attendant production processes associated with the rapid promotion and development of offshore wind farms. Therefore, it is necessary to carry out risk assessment for phases in the life cycle of offshore wind farms. This paper reports on a risk assessment model based on a Dynamic Bayesian network that performs offshore wind farms maritime risk assessment. The advantage of this approach is the way in which a Bayesian model expresses uncertainty. Furthermore, such models permit simulations and reenactment of accidents in a virtual environment. There were several goals in this research. Offshore wind power project risk identification and evaluation theories and methods were explored to identify the sources of risk during different phases of the offshore wind farm life cycle. Based on this foundation, a dynamic Bayesian network model with Genie was established, and evaluated, in terms of its effectiveness for analysis of risk during different phases of the offshore wind farm life cycle. Research results show that a dynamic Bayesian network method can perform risk assessments effectively and flexibly, responding to the actual context of offshore wind power construction. Historical data and almost real-time information are combined to analyze the risk of the construction of offshore wind power. Our results inform a discussion of security and risk mitigation measures that when implemented, could improve safety. This work has value as a reference and guide for the safe development of offshore wind power.
The order of expression is a key factor in the production of active transglutaminase in Escherichia coli by co-expression with its pro-peptide
Song Liu, Dongxu Zhang, Miao Wang, Wenjing Cui, Kangkang Chen, Guocheng Du, Jian Chen, Zhemin Zhou
Microbial Cell Factories , 2011, DOI: 10.1186/1475-2859-10-112
Abstract: A TGase from S. hygroscopicus was expressed in E. coli only after fusing with the pelB signal peptide, but fusion with the signal peptide induced insoluble enzyme. Therefore, alternative protocol was designed by co-expressing the TGase and its pro-peptide as independent polypeptides under a single T7 promoter using vector pET-22b(+). Although the pro-peptide was co-expressed, the TGase fused without the signal peptide was undetectable in both soluble and insoluble fractions of the recombinant cells. Similarly, when both genes were expressed in the order of the TGase and the pro-peptide, the solubility of TGase fused with the signal peptide was not improved by the co-expression with its pro-peptide. Interestingly, active TGase was only produced by the cells in which the pro-peptide and the TGase were fused with the signal peptide and sequentially expressed. The purified recombinant and native TGase shared the similar catalytic properties.Our results indicated that the pro-peptide can assist correct folding of the TGase inter-molecularly in E. coli, and expression of pro-peptide prior to that of TGase was essential for the production of active TGase. The co-expression strategy based on optimizing the order of gene expression could be useful for the expression of other functional proteins that are synthesized as a precursor.Transglutaminase (EC 2.3.2.13, TGase) catalyzes crosslinking between the γ-carboxyamide groups of glutamine residues (acyl donors) and a variety of primary amines (acyl acceptors) in many proteins [1]. In the absence of primary amines, H2O can act as an acyl acceptor, resulting in the deamidation of glutamine residues [1]. Multifunctional TGases are widely found in mammals [2], plants [3], and microorganisms [1]. Since the first microbial TGase was discovered in Streptomyces mobaraensis [4], and many other TGase-producing microbial strains have been identified [5]. The Streptomyces TGase has been widely applied in the food industry to improve the fu
Design of a CPW-Fed Ultra Wide Band Antenna  [PDF]
Shaowen Hu, Yiqiang Wu, Ye Zhang, Huilin Zhou
Open Journal of Antennas and Propagation (OJAPr) , 2013, DOI: 10.4236/ojapr.2013.12005
Abstract: A CPW-fed ultra-wideband antenna was designed. The antenna was etched on a single-layer copper-cladding substrate, of which the material was FR4 with relative permittivity of 4.4, and the magnitude was 40.0 mm × 50.0 mm × 1.6 mm. The parameters of the antenna are simulated and optimized with HFSS. This paper proposes a new trapezoidal CPW-fed UWB antenna that the bandwidth (return loss ≤ ?10 dB) covers 2.7 - 9.3 GHz range, which means a relative bandwidth of 110% with good radiation patterns and gain. Simulated and measured results for return loss, radiation pattern and gain were presented. A good agreement has been obtained between the simulation and experiment and the proposed antenna meets the requirements of the ultra-wideband antenna.
Detection and tracking of clathrin-coated pits in biological images
ZhiFeng Liu,Yun Ge,Dong Zhang,XiaoBo Zhou
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-011-4895-z
Abstract: Dynamically tracking hundreds of individual pits is essential to determine whether there exist “hot spots” for the formation of clathrin-coated pits or if the pits formed randomly on the plasma membrane. We propose an automated approach to detect these particles based on an improved á trous wavelet transform decomposition with automatic threshold selection and post processing solution, and to track the dynamic process with a greedy algorithm. The results indicate that the detection method can successfully detect most particles in an image with accuracy of 98.61% and 97.65% for adaptor and clathrin images, respectively, and that the tracking algorithm can resolve merging and splitting issues encountered when analyzing dynamic, live-cell images of clathrin assemblies.
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