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Generation of marker-free transgenic maize with improved salt tolerance using the FLP/FRT recombination system

JOURNAL OF BIOtechNOLOGY 2010年第2期145卷 206-213页

作者： Li, Bei Li, Ning Duan, Xiaoguang Wei, Aiying Yang, Aifang Zhang, Juren Shandong Univ Sch Life Sci Jinan 250100 Peoples R China

The possible release of selectable marker genes from genetically modified transgenic plants, or of gut microbes, to the environment, has raised worldwide public concerns. In this study, we showed the generation of marker-free transgenic maize plants constitutively expressing AtNHX1, a Na+/H+ antiporter gene from Arabidopsis that conferred salt tolerance on plants, using the FLP/FRTsite-specific recombination system. Transgenic plant expressing a modified FLP recombinase gene was crossed with transgenic plant harboring AtNHX1 and mutant als, a selectable marker gene flanked by two directed FRT sites. The sexual crossing led to precise and complete excision of the FRT-surrounded als marker gene in the F1 progenies. Further salt tolerance examinations indicated that marker-free AtNHX1 transgenic plants accumulated more Na+ and K+, and produced greater biomass and yields than did the wild-type plants when grown in high saline fields. These results demonstrate the feasibility of using this FLP/FRT-based marker elimination system to generate marker-free transgenic important cereal crops with improved salt tolerance. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Marker-free Salt tolerance Transgenic maize FLP/FRT recombination

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Photodynamic Action of LED-activated Nanoscale Photosensitizer in Nasopharyngeal Carcinoma Cells

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LASER PHYSICS 2010年第2期20卷 544-550页

作者： Bai, D. Q. Yow, C. M. N. Tan, Y. Chu, E. S. M. Xu, C. S. Hong Kong Polytech Univ Dept Hlth Technol Informat Hong Kong Hong Kong Peoples R China Chongqing Med Univ Affiliated Hosp 2 Dept Photodynam Therapy & Sonodynam Therapy Chongqing Peoples R China

Background: Photodynamic therapy has been confirmed to an efficient therapeutic modality of malignant tumors. The aim of the present study was to explore the photodynamic action of LED-activated nanoscale photosensitizer-loading hypocrellin in nasopharyngeal carcinoma cells. Material/Methods: Nasopharyngeal carcinoma cell line CNE2 cells were subjected to photodynamic therapy with hypocrellin-loaded nanophotosensitizer. The uptake of the nanophotosensitizer in the CNE-2 cells was measured using a spectrophotometer and photodynamic toxicity was investigated 18 h after LED radiation treatment. Apoptosis was determined using flow cytometry with propidum iodine staining, and nuclear staining with Hoechst 33258. Active caspase-3 in the CNE2 cells was evaluated using flow cytometry with phycoerythrin (PE)-conjugated anti-active caspase-3 antibodies. Results: The cellular uptake of the nanophotosensitizer in the CNE-2 cells reached optimal at 6 h. LED-activated nanophotosensitizer resulted in dose-and light-dependent phototoxicity. Apoptotic rate 18 h after PDT increased to 34.32 +/- 1.94% under the light energy of 1 J/cm(2). Hoechest 33258 staining reinforced the findings above. Condensation of chromatin and nuclear fragmentations was found in many PDT-treated cells. The activated caspase-3 in the CNE2 cells significantly increased up to 43.90% when the CNE2 cells were exposed to the nanophotosensitizer for 6 h and then 1 J/cm(2) irradiation. Conclusion: LED-activated nanophotosensitizer significantly killed the CNE2 cells and enhanced apoptosis and activated caspase-3 in the CNE2 cells. The hypocrellin-loaded nanophotosensitizer might be efficient photosensitizer and LED-activated nanophotosensitizer can be developed for treating nasopharyngeal carcinoma.

关键词： Light emitting diodes

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Comparative study of properties of immobilized lipase onto glutaraldehyde-activated amino-silica gel via different methods

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COLLOIDS AND SURFACES B-BIOINTERFACES 2010年第2期78卷 351-356页

作者： Yang, Guang Wu, Jianping Xu, Gang Yang, Lirong Zhejiang Univ Coll Mat Sci & Chem Engn Inst Bioengn Hangzhou 310027 Zhejiang Peoples R China

The enzyme-aggregate coating method was performed to immobilize Arthrobacter sp. lipase in order to achieve better catalytic properties comparable to the conventional covalent attachment and covalent attachment plus cross-linking. The glutaraldehyde-activated amino-silica gel which was synthesized by sol-gel technique was used as the support, and the catalytic characteristics of the lipase preparations were tested in the asymmetric acylation of 4-hydroxy-3-methyl-2-(2-propenyl)-2-cyclopenten-1-one (HMPC) in organic solvents. The results showed that the immobilized lipase by enzyme-aggregate coating possessed both higher activity and stability than those by other methods, e.g. it obtained an activity of 82.6 U/g and remained 42% and 93% of the original activity after incubation in vinyl acetate at 60 degrees C for 16h and 9 times recycles, respectively, while the covalently attached lipase got an activity of 67.4 U/g and left 33% and 73% of the original under the same conditions, and the enzyme prepared by covalent attachment plus cross-linking exhibited the lowest activity yield. Moreover, excellent enantioselectivity (E >= 400) was achieved by all the three prepared lipases in our paper (E = 85 for the free enzyme). (C) 2010 Elsevier B.V. All rights reserved.

关键词： Enzyme-aggregate coating Lipase Glutaraldehyde-activated amino-silica gel Stability Enantioselectivity Asymmetric acylation

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Identification and Analysis of Polychlorinated Biphenyls (PCBs)-Biodegrading Bacterial Strains in Shanghai

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CURRENT MICROBIOLOGY 2010年第5期61卷 477-483页

作者： Shuai, Jian-Jun Tian, Yong-Sheng Yao, Quan-Hong Peng, Ri-He Xiong, Fei Xiong, Ai-Sheng Yangzhou Univ Coll Biosci & Biotechnol Yangzhou 225009 Peoples R China Shanghai Acad Agr Sci Biotechnol Res Inst Shanghai Peoples R China

As one of china's great metropolises, Shanghai is vulnerable to various forms of industrial and agricultural contamination associated with its development. Polychlorinated biphenyls (PCBs) are man-made chemicals that never existed in nature until the 1900s when they started to be released into the environment. PCBs are hazardous environmental contaminants that bind strongly to soil. In this study, four soil samples were screened for the presence of PCB-degrading bacteria. The 16 S rDNAs were amplified from those genomes and the products (similar to 1.5 kb) were purified and sequenced for the isolation and identification of bacterial species. Four Pseudomonas strains (strain 1-212 from sample 1;strain 2-241 from sample 2;strain 3-318 from sample 3;and strain 4-150 from sample 4) were selected for analysis by HPLC. Setting the content of the biphenyl in CK as 100%, the biphenyl contents was 2.32% in 1-212, 73.11% in 2-241, 69.83% in 3-318, and 86.16% in 4-150. The results of this study suggest directions for future research, including genetic screening, cloning and restructuring, and provide guidance for the cultivation of PCBs-degrading bacteria.

关键词： POLYCHLORINATED biphenyls ORGANOCHLORINE compounds PRINTED circuits BIPHENYL compounds GENOMICS

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Study on the aggregation of transglutaminase on soybean protein hydrolysates

Study on the aggregation of transglutaminase on soybean prot...

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4th International Conference on Bioinformatics and Biomedical Engineering (iCBBE)

作者： Yang Chunhua Shi Yanguo Liu Ying Fan Tingting Zhang Yifang Hu Chunlin Harbin Univ Commerce Inst Food & Engn Harbin Peoples R China Harbin High Tech Soybean Food Co Ltd Dept Technol Harbin Peoples R China

ISBN: (纸本)9781424447138

Taking soybean protein hydrolysates (SPH) hydrolyzed by papain as substrates, the effects of transglutaminase on soybean protein hydrolysates were studied using the single factors of temperature, time, the ratio of emzyme to protein and pH value. The molecular weight data indicated that transglutaminase could be used as catalyst to aggregate SPH. The solution of the concentration of the enzyme for 25U/g SPH, after heating 40 degrees C for 9h, under pH 7 and formed aggregates with different aggregation profiles. It was also found, by Nitrogen Solubility Index(NSI) measurement, the level of NSI was in the order of native soybean protein< soybean protein hydrolyzed by papain< soybean protein aggregated by transglutaminase. Both these results showed that when SPH aggregated by transglutaminase, the molecular weight of SPH increased obviously, the solubility of SPH was improved to a certain extent. The aggregation character might be widely used as a source of highly functional soybean protein in more food products.

关键词： soybean protein transglutaminase aggregate

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A breath sensor using carbon nanotubes operated by field effects of polarization and ionization

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SENSORS AND ACTUATORS A-PHYSICAL 2010年第2期158卷 328-334页

作者： Chen, Xiaohang Wang, Yanyan Wang, Yuhua Hou, Zhongyu Xu, Dong Yang, Zhi Zhang, Yafei Shanghai Jiao Tong Univ Inst Micronano Sci & Technol Natl Key Lab Nanomicro Fabricat Technol Key Lab Thin Film & MicrofabricatMinist Educ Shanghai 200240 Peoples R China

A novel microfabricated breath sensor (MBS) based on multi-walled carbon nanotubes (MWNTs) has been presented and tested. It has a simple structure of two nickel beams incorporating with MWNTs. The responses of the MBS to the behavior of the breath dynamic characteristics are consistent with the exhalation pulse of the human-volunteers, e.g. the exhale flow strength and frequency. It has a rapid response and high sensitivity in detecting feeble breath, and no recovery issues such as the adsorption-type sensors are detected. Furthermore, strong anti-interference ability to external air flow and temperature shift is observed. These unique results ensure this MBS can be successfully employed to real-time monitoring of human breath. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Microfabrication breath sensor Multi-walled carbon nanotubes Exhaled breath Response Sensitivity

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Generalized analysis model for fractional frequency reuse

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The Journal of china Universities of Posts and Telecommunications 2010年第5期17卷 1-5页

作者： XI Wei YIN Chang-chuan YUE Guang-xin SUN Hong-mei Laboratory of Wireless Cornmtmication Systems and Networks Beijing University of Posts and Telecommunications Beijing 100876 China Communication Technology Laboratory Intel China Research Center Beijing 100190 China

Fractional frequency reuse （FFR） is an effective technique to mitigate co-channel interference in orthogonal frequency division multiple access （OFDMA）-based broadband cellular *** this paper,we present a generalized model for FFR under which all existing FFR schemes can be considered as its special ***,quality factor has been proposed to indicate the quality of the *** interesting conclusion can be drawn that,as the power ratio in FFR is adjusted continuously,the corresponding quality factor varies ***,simulation is conducted based on worldwide interoperability for microwave access （WiMAX）,and the result agrees well with our theoretical ***,an effective range for power ratio is presented,which is very instructive to practical system design.

关键词： co-channel interference FFR power ratio

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Cooling rate effect of nanomechanical response for a Ti-based bulk metallic glass

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JOURNAL OF NON-CRYSTALLINE SOLIDS 2010年第20-22期356卷 966-970页

作者： Huang, Yongjiang Chiu, Yu Lung Shen, Jun Chen, John J. J. Sun, Jianfei Univ Birmingham Sch Met & Mat Birmingham B15 2TT W Midlands England Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China Univ Auckland Dept Chem & Mat Engn Auckland 1142 New Zealand

The effect of cooling rate on the mechanical behaviors of a Ti-based bulk metallic glass has been studied using nanoindentation technique. It is found that the hardness increases, while the plastic deformation capacity gradually decreases from the edge to the center of the sample. The variation of the structural uniformity within the as-cast glassy sample may account for the cooling rate dependence of mechanical performance. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Amorphous metals Metallic glasses Alloys Hardness Indentation Microindentation

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Design and Simulation of a MEMS Control Moment Gyroscope for the Sub-Kilogram Spacecraft

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SENSORS 2010年第4期10卷 4130-4144页

作者： Chang, Honglong Jiao, Wenlong Fu, Qianyan Xie, Jianbing Yuan, Weizheng Northwestern Polytech Univ Micro & Nano Electromech Syst Lab Xian Shaanxi Peoples R China

A novel design of a microelectromechanical systems (MEMS) control moment gyroscope (MCMG) was proposed in this paper in order to generate a torque output with a magnitude of 10(-6) N.m. The MCMG consists of two orthogonal angular vibration systems, i.e., the rotor and gimbal;the coupling between which is based on the Coriolis effect and will cause a torque output in the direction perpendicular to the two vibrations. The angular rotor vibration was excited by the in-plane electrostatic rotary comb actuators, while the angular gimbal vibration was driven by an out-of-plane electrostatic parallel plate actuator. A possible process flow to fabricate the structure was proposed and discussed step by step. Furthermore, an array configuration using four MCMGs as an effective element, in which the torque was generated with a phase difference of 90 degrees between every two MCMGs, was proposed to smooth the inherent fluctuation of the torque output for a vibrational MCMG. The parasitic torque was cancelled by two opposite MCMGs with a phase difference of 180 degrees. The designed MCMG was about 1.1 cm x 1.1 cm x 0.04 cm in size and 0.1 g in weight. The simulation results showed that the maximum torque output of a MCMG, the resonant frequency of which was approximately 1,000 Hz, was about 2.5 x 10(-8) N.m. The element with four MCMGs could generate a torque of 5 x 10(-8) N.m. The torque output could reach a magnitude of 10(-6) N.m when the frequency was improved from 1,000 Hz to 10,000 Hz. Using arrays of 4 x 4 effective elements on a 1 kg spacecraft with a standard form factor of 10 cm x 10 cm x 10 cm, a 10 degrees attitude change could be achieved in 26.96 s.

关键词： MEMS microactuator control moment gyroscope attitude control sub-kilogram spacecraft

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A Flexible Optical Packet Compression and Routing Scheme by Using an Active Vertical Coupler-Based Optical Crosspoint Switch Matrix

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IEEE COMMUNICATIONS MAGAZINE 2010年第8期48卷 146-151页

作者： Shao Yufeng Zhang Junwen Fang Wuliang Huang Bo Chi Nan Fudan Univ State Key Lab ASIC & Syst Full Waveband Commun Lab FAVOR Shanghai 200433 Peoples R China Fudan Univ Dept Commun Sci & Engn FAVOR Shanghai 200433 Peoples R China

We experimentally demonstrate all-optical packet compression for an RZ payload up to 40 Gb/s and a label at 155 Mb/s, based on a recirculating buffer with one individual optical crosspoint switch. The packet can be flexibly switched, dropped, time slot interchanged up to 9 time slots, and compressed up to 4 packets in one time slot. Back-to-back BER performance of the 4 times compressed packet was measured with only 1.8 dB of power penalty. By using variable fiber delay lines, this scheme can be further extended to applications for variable length/time slot packet routing and compression.

关键词： Routing Optical coupling Optical packet switching Optical switches Communication switching Optical fiber communication Optical buffering Payloads Bit error rate Power measurement

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