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Profiling influences of gene overexpression on heterologous resveratrol production in Saccharomyces cerevisiae

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Frontiers of Chemical Science and Engineering 2017年第1期11卷 117-125页

作者： duo liu Bingzhi Li Hong liu Xuejiao Guo Yingjin Yuan Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China SynBio Research Platform Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Tianjin 300072 China

Metabolic engineering of heterologous resver- atrol production in Saccharomyces cerevisiae faces challenges as the precursor L-tyrosine is stringently regulated by a complex biosynthetic system. We over- expressed the main gene targets in the upstream pathways to investigate their influences on the downstream resver- atrol production. Single-gene overexpression and DNA assembly-directed multigene overexpression affect the production of resveratrol as well as its precursor p-coumaric acid. Finally, the collaboration of selected gene targets leads to an optimal resveratrol production of 66.144-3.74 mg.L-1, 2.27 times higher than the initial production in YPD medium （4% glucose）. The newly discovered gene targets TRP1 expressing phosphoribosy- lanthranilate isomerase, AR03 expressing 3-deoxy-D- arabino-heptulosonate-7-phosphate synthase, and 4CL expressing 4-coumaryl-CoA ligase show notable positive impacts on resveratrol production in S. cerevisiae.

关键词： resveratrol aromatic amino acid DNA assem-bly metabolic engineering gene overexpression

Enhanced Second-Order Resonance Actuation and Frequency Response Modulation of Microcantilever by Dual Coplanar Counter Electrodes

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Chinese Physics Letters 2013年第10期30卷 42-45页

作者： FENG Zhao-Bin liu duo State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100

We achieve enhanced actuation of the 2^(nd)-order resonance of a microcantilever in a capacitive microcantilever structure featured by a dual coplanar counter electrodes configuration.A torque about the static point of the 2^(nd) eigenmode is generated in this configuration and therefore enables effective actuation of the 2^(nd)-order *** is further confirmed that the torque has the effect of suppressing the 1^(st)-order *** a result,the frequency response curve of the microcantilever beam can be *** results suggest that electric actuation of any higher-order resonances of the microcantilever can be realized through a rational design of counter electrodes.

关键词： cantilever planar rational

Designing reduced beacon trajectory for sensor localization

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第12期8卷 1971-1982页

作者： HUANG Wen-liang LI Shi-jian liu duo School of Computer Science Zhejiang University Hangzhou 310027 China Graduate School Zhejiang University Hangzhou 310027 China

Localization is one of the substantial issues in wireless sensor networks. The key problem for the mobile beacon localization is how to choose the appropriate beacon trajectory. However, little research has been done on it. In this paper, firstly, we deduce the number of positions for a beacon to send a packet according to the acreage of ROI (region of interest); and next we present a novel method based on virtual force to arrange the positions in arbitrary ROI; then we apply TSP (travelling salesman problem) algorithm to the positions sequence to obtain the optimal touring path, i.e. the reduced beacon trajectory. When a mobile beacon moves along the touring path, sending RF signals at every position, the sensors in ROI can work out their position with trilateration. Experimental results demonstrate that the localization method, based on the beacon reduced path, is efficient and has flexible accuracy.

关键词： Sensor network Sensor localization Mobile beacon Virtual force

Wetting behavior of AgCu-4.5Ti filler reinforced by carbon nanotubes on C/C composite

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Chinese Journal of Aeronautics 2021年第12期34卷 205-213页

作者： Xingyi LI Ling liu Yanyu SONG duo liu Shengpeng HU Xiaoguo SONG Jian CAO State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Prorincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China Hun cm Marketing Company PetroChina Company LimitedChangsha 410005China

The effect of Carbon Nanotubes(CNTs)content on the wettability of AgCu-4.5Ti+x CNTs(wt%)composite filler alloys on C/C composite was *** results show that the added CNTs reacted with element Ti in the filler and produced the dispersed fine in situ synthesized TiC particles,which increased the consumption of element Ti and provided the nucleus for the growth of Ti-Cu compounds *** above effects of introducing CNTs,inhibited the formation of Ti-Cu compounds,also changed the distribution of compounds,which dramatically influenced the interfacial microstructure and characteristics of wetting *** increase of CNTs content refined and dispersed coarse Ti-Cu compounds,decreased the initial spreading temperature,and improved the wettability,but high content of CNTs(more than 0.3 wt%)decreased the wettability of the filler *** wetting interfacial microstructure of corresponding composite filler alloys were analyzed by Scanning Electron Microscope(SEM),Energy Dispersive X-ray Spectrometer(EDS)and Transmission Electron Microscope(TEM),which consisted of TiC,TiCu,TiCu;and TiCu;*** typical wetting behavior of AgCu-4.5Ti+0.3wt%CNTs composite filler on C/C composite was divided into four *** effect mechanism of CNTs content on the wetting behavior was proposed.

关键词： C/C composite Carbon Nanotubes(CNTs) Composite filler Microstructure Wetting

Synthesis of Long Chain Fatty Acids Acylated Coumarin Glycoside Esters with Lipase as Catalyst

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Chemical Research in Chinese Universities 2015年第4期31卷 534-538页

作者： liu duo CAI Shuanglian LUAN Fangjian WANG Qiu'an State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University Changsha 410082 P. R. China

A series of novel coumarin glycoside esters（1-9） was synthesized through the acylation reaction of 4-methylcoumarin-7-O-β-D-glucoside（11） with different long chain fatty acids catalyzed by lipase in organic medium. The acylation occurred regioselectively at the 6＇-OH of glycosyl moiety. The enzymatic synthesis was optimized to achieve 54%-70% yield using immobilized lipase（Novozym 435, 10 mg/mL） as catalyst and acetone and pyri- dine（9：1, volume ratio, water content〈1%） as solvent with an acyl donor/coumarin glycoside molar ratio of 10：1 at a temperature of 40--50 ℃ for 96 h. All the synthesized compounds were confirmed.

关键词： Coumarin glycoside Lipase-catalyzed acylation Long chain fatty acid Regioselective acylation

Shape control technology during electrochemical synthesis of gold nanoparticles

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International Journal of Minerals,Metallurgy and Materials 2013年第5期20卷 486-492页

作者： Xiu-yu liu Cong-ying Cui Ying-wen Cheng Hou-yi Ma duo liu State Key Lab of Crystal Materials Institute of Crystal MaterialsShandong University New Material Institute of Shandong Academy of Sciences School of Chemistry and Chemical Engineering Shandong University

Gold nanoparticles with different shapes and sizes were prepared by adding gold precursor （HAuC14） to an electrolyzed aqueous solution of poly（N-vinylpyrrolidone）（PVP） and KN03, which indicates the good reducing capacity of the PVP-containing solution after being treated by electrolysis. Using a catholyte and an anolyte as the reducing agents for HAuC14,＇ respectively, most gold nanoparticles were spherical particles in the former case but plate-like particles in the latter case. The change in the pH value of electrolytes caused by the electrolysis of water would be the origin of the differences in shape and morphology of gold nanoparticles. A hypothesis of the H＋ or OH- catalyzed PVP degradation mechanism was proposed to interpret why the pH value played a key role in determining the shape or morphology of gold nanoparticles. These experiments open up a new method for effectively controlling the shape and morphology of metal nanoparticles by using electrochemical methods.

关键词： metal nanopaxticles synthesis gold shape control electrochemical methods

Preparation and Characterization of Sulfated Cellulose Nanocrystalline and its Composite Membrane for Removal of Tetracycline Hydrochloride in Water

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Energy & Environmental Materials 2020年第2期3卷 209-215页

作者： Jie liu duo liu Shisheng liu Zhihong Li Xiaohui Wei Song Lin Minjie Guo College of Chemical Engineering and Materials Science Tianjin University of Science&TechnologyTianjin 300457China Institute of Medical Support Academy of Military SciencesTianjin 300161China

The removal of antibiotic pollutants remaining in the environmental media has been a big challenge ***,we report a facile and green approach to fabricate an eco-friendly composite membrane without addition of any toxic polymers or chemical cross-linking agents to effectively remove the tetracycline hydrochloride in ***,the sulfated cellulose nanocrystalline(CNC) was obtained via hydrolysis of sulfuric acid by using microcrystalline cellulose(MCC) as raw material under ultrasonic *** as-prepared CNC has a nanowhisker dimension with 200.2 ± 110.2 nm in length,15.7 ± 9.3 nm in width,and 7.2 ± 3.1 nm in *** obtained CNC is cellulose type I as determined by X-ray diffraction(XRD),while its crystallinity index(Crl) can reach 82.3%.Then,the composite membrane derived from the obtained CNC and commercial mixed cellulose ester(MCE)membrane was facilely prepared through vacuum dewatering process,which is applied to remove tetracycline hydrochloride(Th) in *** results showed that the removal efficiency of Th through the neat MCE was only28 ± 4%,while it could be improved to 58 ± 5% and 89 11%,respectively,by filtering through composite membranes with different contents of CNC *** effect is derived from the combine factors based on both steric hindrance(sieving) and electrostatic interaction(Donnan) effect of the composite *** development of related CNC materials and composite fabrication processes is in favor of cost-effective and "green"polymer composites for the remediation of increasing antibiotic pollution and the purification of contaminated water nowadays.

关键词： adsorption removal cellulose nanocrystalline composite membrane tetracycline hydrochloride

Joining of SiO2 ceramic and TC4 alloy by nanoparticles modified brazing filler metal

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Chinese Journal of Aeronautics 2020年第1期33卷 383-390页

作者： Hong BIAN Yanyu SONG duo liu Yuzhen LEI Xiaoguo SONG Jian CAO State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Provincial Key Lab of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China

Nano-Al2O3 particles modified Ag Cu Ni filler was adopted to braze the SiO2 ceramic and *** effects of filler size as well as the brazing temperature on the interfacial microstructure and mechanical property of the joints were *** filler reduced the phases dimension and promoted the homogeneous distribution of microstructure,obtaining a higher joint strength when compared to microscale *** increase of brazing temperature made the accelerating dissolution and diffusion of Ti,which promoted the increase of thickness of Ti4O7+TiSi2 layer adjacent to SiO2 ceramic and diffusion layer zone nearby TC4 *** hypoeutectic structure was produced in the brazing seam due to the high Ti *** maximum shear strength of^40 MPa was obtained at 950°C for 10 min.

关键词： Brazing Microstructure Nanoparticles modified filler SiO2 ceramic TC4

A Lightweight Three-Factor User Authentication Protocol for the Information Perception of IoT

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Computers, Materials & Continua 2019年第2期58卷 545-565页

作者： Liang Kou Yiqi Shi Liguo Zhang duo liu Qing Yang College of Computer Science and Technology Harbin Engineering UniversityHarbin150001China 2Harbin University of Commerce Harbin150001China 3University of North Texas Denton76207USA

With the development of computer hardware technology and network technology,the Internet of Things as the extension and expansion of traditional computing network has played an increasingly important role in all professions and trades and has had a tremendous impact on people *** information perception of the Internet of Things plays a key role as a link between the computer world and the real ***,there are potential security threats in the Perceptual Layer Network applied for information perception because Perceptual Layer Network consists of a large number of sensor nodes with weak computing power,limited power supply,and open communication *** proposed a novel lightweight authentication protocol based on password,smart card and biometric identification that achieves mutual authentication among User,GWN and sensor *** identification can increase the nonrepudiation feature that increases *** security analysis and logical proof,the proposed protocol is proven to have a higher reliability and practicality.

关键词： Authentication biometrics smart card multi-factor