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Search Results: 1 - 10 of 11857 matches for " Wanru Xie "
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Amino terminus mutant OmpA from an isolated antibiotic resistant Escherichia coli still possess resistance to environmental stresses  [PDF]
Zhiping Zhao, Xin Nie, Zaixin Li, Zhi Zhang, Jie Ding, Wanru Xie
Advances in Biological Chemistry (ABC) , 2013, DOI: 10.4236/abc.2013.31014

Antibiotic resistant Escherichia coli strains are becoming more common recently. OmpA is a very important antigen protein of E. coli, which consists of two separate domains, N-terminal and C-terminal domain. The N-terminal domain contains eight β- barrel regions that plays important roles in the multifaceted functions of OmpA. In the present study, we cloned a mutant OmpA gene from a multi-antibiotic resistant E. coli strain. Sequence analysis indicated that the N-terminal DNA sequence of the mutant OmpA shared 81.05% homology with the modeled OmpA from E. coli K12 and the N-terminal amino acid sequence of the mutant OmpA was 81.22% identical to that of the E. coli K12 OmpA. Moreover, several amino acids located in the β-barrel region were mutated. The mutant OmpA was expressed in BL21 suggested by SDS-PAGE. Resistance to environmental stress assay indicated that the N-terminus mutant OmpA still possessed excellent activities in pH, temperature and osmotic pressure resistance. Our pre- sent study may supply insights into better and deeper understand the relationships between OmpA N-terminal regions and its functions in environmental stress conditions and the mechanisms on antibiotic resistance of E. coli.

The Study of Electromagnetic Stress Testing Method on Oil-Gas Pipelines Based on WT  [PDF]
Bin Liu, Wanru Sun, Yiren Lin
Geomaterials (GM) , 2014, DOI: 10.4236/gm.2014.42006
Abstract: This paper proposes an effective method for early diagnosis (stress concentrating) of the oil-gas pipeline. Based on the principle of electromagnetic induction Faraday, we have designed and realized the nondestructive testing system for stress concentration area of ferromagnetic materials by means of the research of metal materials inverse magnetostrictive effect mechanism. The system changes the influence degree of the stress in ferromagnetic materials’ magnetic conductance to the corresponding voltage array by using discrete wavelet analysis method to process the data, in which not only the measuring accuracy is improved, but also the stress concentration is more directly reflected. The experiments confirm that the electromagnetic stress testing method is feasible and valid.
Studies on the Conditions of Fermentation of Pullulan by Aureobasidium pullulans

Sun Wanru - Zhou Tiesuo Xie Haoxu Ren Yonge Jiang Ning,

生物工程学报 , 1994,
Abstract: The studies on suitable conditions for pullulan fermentation according to the results obtained from the shaking flask tests was carried out in 16L auto-controlling fer-mentor. It fount that the optimal DE value of starch hydrolyzate was 40-50 when 10% starch was used as carbon source. The optimal concentration of ammonium sulfate in the medium for fermentor was different from that of the shaking flask. The fermentation kinetics and effects of seed age, seed volume, airflow rate, pressure of tank, agitation speed and number of vane group on the production of pullulan were investigated.

Ren Yonge,Jiang Ning,Xie Haoxu,Zhou Tiesuo,Sun Wanru,

微生物学通报 , 1995,
Abstract: 将已有的4株出芽短梗霉在摇瓶中于不同发酵条件下进行比较,考察了它们的生长情况,不同的碳源、氮源、磷酸盐、初始pH和通气量等对短梗霉多糖合成的影响,获得一株产短梗霉多糖的高产菌株,为以后工作打下良好基础。
Ratio quantification of gene dosage by Agilent 2100 Bioanalyzer for detection of somatic gene deletions  [PDF]
Peter Hwu, Qiang Liu, Yafan Wang, Linling Chen, Yawen Cheng, Wanru Lin, Yun Yen
Advances in Biological Chemistry (ABC) , 2012, DOI: 10.4236/abc.2012.21009
Abstract: We applied the Agilent 2100 Bioanalyzer, a microfluidics-based electrophoresis instrument, and introduced an accurate and consistent parameter, the relative product yield ratio (ROY), to detect somatic gene deletions in tumor cells. Briefly for such purpose, the Agilent 2100 Bioanalyzer quantified the ROY of a target gene to an endogenous internal control, both of which were initially co-amplified by Robust-Dosage PCR (RD- PCR). Herein, we extensively validated this approach. We first tested the effect of well positions on the Agilent DNA chip. We found that no matter which wells the samples were loaded in, the ROY was consistent with coefficient of variation (CV) < 2%. Then we tested the effect of product concentrations that varied 8-fold, and the ROY was also consistent with CV < 3.5%. Furthermore, we applied this approach to identify six somatic KRAS deletions in non-small cell lung cancer patients, confirming our previous findings. Thus, the Agilent 2100 Bioanalyzer is simple, accurate, quick, and ultimately able to replace conventional gel electrophoresis for the detection of somatic gene deletions.
Study on Isolation and Purification of Penicillin Acylase by Adsorption on Bentonite

Sun Wanru,

生物工程学报 , 1994,
Abstract: Bentonite I as an absorbent according to 0. 65% (w/v) was added into the supernatant of fermentation broth for adsorption of penicillin acylase from Bacillus megatherium. It found that 100% activity of penicillin acylase and about 10% protein in the supernatant were adsorbed. The adsorption of enzyme was not obviously changed by different pH and salt .concentration of the supernatant. Verious kinds of buffer having different pH were used to wash the adsorbent-enzyme complex. Only 1 % enzyme activity adsorbed was washed out, however, it can wash out about 15% protein adsorbed. When phosphate buffer containing 10% PEG and NaCl as an eluent was used to elute the complex, 100% of enzyme activity adsorbend on the complex would be eluted, and purification and concentration of enzyme could achieve about 25 and 6 fold, respectively. The isolation and purification process can be carried out at room temperature. Its characters were very simple and high recovery yield of enzyme activity, and it can be directly used for isolation and purification of penicillin acylase from the fermentation broth.
Studies on the Binding Mechanism of VB1 and VB9 with Trypsin  [PDF]
Yan Gao, Congying Shao, Wanru Ji, Min Xiao, Fan Yi, Tong Zhou, Yanqin Zi
American Journal of Analytical Chemistry (AJAC) , 2013, DOI: 10.4236/ajac.2013.412094

The binding characteristics of vitamin B1 (VB1) and vitamin B9 (VB9) with trypsin were investigated by fluorescence spectrometry and UV/vis spectrophotometry under simulated physiological conditions. With the addition of VB1 or VB9, the intrinsic fluorescence emission intensity of trypsin was quenched by the nonradiative energy transfer mechanism. The fluorescence quenching process of trypsin may be mainly governed by a static quenching mechanism. The binding parameters such as the binding constants and the number of binding sites can be evaluated by fluorescence quenching experiments. The numbers of the apparent binding constant Kb of VB1-trypsin at different temperatures were 0.4948 and 4.8340 × 104 L/mol and the numbers of binding sites n were 0.9359 and 1.1820. Similarly, the numbers of the apparent binding constant Kb of VB9-trypsin at different temperatures were 5.9310 and 13.040 × 10

Feature-Based Diversity Optimization for Problem Instance Classification
Wanru Gao,Samadhi Nallaperuma,Frank Neumann
Computer Science , 2015,
Abstract: Understanding the behaviour of heuristic search methods is a challenge. This even holds for simple local search methods such as 2-OPT for the Traveling Salesperson problem. In this paper, we present a general framework that is able to construct a diverse set of instances that are hard or easy for a given search heuristic. Such a diverse set is obtained by using an evolutionary algorithm for constructing hard or easy instances that are diverse with respect to different features of the underlying problem. Examining the constructed instance sets, we show that many combinations of two or three features give a good classification of the TSP instances in terms of whether they are hard to be solved by 2-OPT.
Improvement and Design of Transmitter Modifier Wind Cooling Protection for CINRAD/CB Weather Radar  [PDF]
Shi Zheng, Guan Wang, Xingyou Huang, Chuanhai Miao, Wanru Xing, Simeng Chen, Boshi Kang
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.611011
Abstract: Doppler weather radar has important applications in measuring the intrinsic factors of cloud, rainfall and various convective weather occurrences. Among them, CINRAD/CB Doppler weather radar is based on the requirements of the China Meteorological Administration and many units have been provided. The modulator is a critical part of the transmitter’s high voltage, where high voltage, high current, and energy conversion are concentrated. It is therefore necessary to redesign the transmitter modulator cooling system protection. This article describes the new design of hardware and software solutions. The fan is a DV5214/2N DC fan from Ebmpapst, Germany. The speed is up to 5000 rpm, the power is 18.5 W, and the single fan current is about 0.8 A. It is powered by 28 V. The protection board uses a DC/DC module to output a 5 V voltage and a 3.3 V voltage adjustment chip LM1117. The embedded web software is based on the TCP/IP protocol stack provided by MICROCHIP. After the cooling system is designed and installed in the radar station in Xi’an, China and other places, after long-term operation, the comprehensive test shows that the system runs well.
A Novel Sliding Mode Control Technique for Indirect Current Controlled Active Power Filter
Juntao Fei,Tianhua Li,Feng Wang,Wanru Juan
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/549782
Abstract: A novel sliding mode control (SMC) method for indirect current controlled three-phase parallel active power filter is presented in this paper. There are two designed closed loops in the system: one is the DC voltage controlling loop and the other is the reference current tracking loop. The first loop with a PI regulator is used to control the DC voltage approximating to the given voltage of capacitor, and the output of PI regulator through a low-pass filter is applied as the input of the power supply reference currents. The second loop implements the tracking of the reference currents using integral sliding mode controller, which can improve the harmonic treating performance. Compared with the direct current control technique, it is convenient to be implemented with digital signal processing system because of simpler system structure and better harmonic treating property. Simulation results verify that the generated reference currents have the same amplitude with the load currents, demonstrating the superior harmonic compensating effects with the proposed shunt active power filter compared with the hysteresis method.
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