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Establishment and application of both FLP and Cre site-specific recombination systems at the same position in the genome

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Chinese Science Bulletin 2000年第5期45卷 456-460页

作者： Jilong Chen Jie Liu Yulian Zhang Zhiwei Chen Zhenhua Jin Chinese Acad Sci Inst Dev Biol Beijing 100080 Peoples R China

Both FRT-FRT and LoxP-LoxP sites that are the target sepuences of site-specific recombinases have been constructed in a vector, called C4LFY, using the recombinant DNA technigue. C4LFY also contains P elements, 2 exons and 1 intron of Drosophila yellow gene, yellow promoter and enhancers, and flanking DNA. Since C4LFY made use of two pairs of FRT and LoxP sites, this vector included two site-specific recombination systems. C4LFY was then integrated into Drosophila genome by P-element-mediated germ line transformation. in the presence of the FLP or Cre recombinase, either FLP/FRT or Cre/LoxP recombination reaction was successfully created at the same position in the genome. Using this system, the molecular basis of yellow gene expression and regulation during development have been investigated. Results indicate that the tissue-specific expression of yellow gene is directly regulated by transcriptional enhancers. in addition, the 5’ and 3’ genomic sequences flanking the yellow gene have been

关键词： site-specific recombination transgene gene expression and regulation cis-acting elements.

Co-transformation to tobacco of Cre/lox site-specific recombination system and its precise recombination

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Chinese Science Bulletin 2000年第6期45卷 540-543页

作者： Lei Li Songmei Liu Yuanlei Hu Zhongping Lin Peking Univ Natl Lab Prot Engn & Plant Genet Engn Beijing 100871 Peoples R China

For the temporally and spatially regulated expression of the barnase gene in plant, two kinds of plasmids with ere gene and its directly repeat recognition sites lox from bacteriophage P1 were constructed and co-transformed into tobacco by agrobacterium mediated procedure. The transgenic plants were conformed by PCR analysis. The blocking fragment between the two lox directly repeat sites was excised by Cre protein in the transgenic plant genome. Cloning and seguencing the DNA fragment from the co-transformed plant DNA showed that the precise DNA excision occurred in transgenic tobacco genome directed by Cre//ox site-specif ic recombination .

关键词： Cre/lox site-specific recombination system tobacco co-transformation precise recombination.

STUDY ON MULTI-POINT site-specific MUTAGENESIS——DOUBLE-POINT site-specific MUTAGENESIS FOR MODIFYING α-HUMAN ATRIAL NATRIURETIC PEPTIDE GENE

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Chinese Science Bulletin 1990年第3期35卷 232-238页

作者：杨迪谢毅施文闵永洁王启松 Institute of Genetics Fudan University Shanghai 200433 PRC

Although oligonucleotide-directed mutagenesis has been widely applied in the field of molecular biology, this method has some disadvantages: It is time-consuming and overelaborate, besides only a single base mutation ... 详细信息

关键词： site-specific mutagenesis double-point site-specific mutagenesis α-human atrial natriuretic peptide.

An integrated approach to site-specific management zone delineation

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Frontiers of Agricultural Science and Engineering 2018年第4期5卷 432-441页

作者： Yuxin MIAO David J.MULLA Pierre C.ROBERT Precision Agriculture Center Department of SoilWater and ClimateUniversity of Minnesota

Dividing fields into a few relatively homogeneous management zones(MZs) is a practical and costeffective approach to precision agriculture. There are three basic approaches to MZ delineation using soil and/or landscape properties, yield information, and both sources of information. The objective of this study is to propose an integrated approach to delineating site-specific MZ using relative elevation, organic matter, slope, electrical conductivity, yield spatial trend map, and yield temporal stability map(ROSE-YSTTS) and evaluate it against two other approaches using only soil and landscape information(ROSE) or clustering multiple year yield maps(CMYYM). The study was carried out on two no-till corn-soybean rotation fields in eastern Illinois, USA. Two years of nitrogen(N) rate experiments were conducted in Field B to evaluate the delineated MZs for site-specific N management. It was found that in general the ROSE approach was least effective in accounting for crop yield variability(8.0%–9.8%), while the CMYYM approach was least effective in accounting for soil and landscape(8.9%–38.1%), and soil nutrient and pH variability(9.4%–14.5%). The integrated ROSE-YSTTS approach was reasonably effective in accounting for the three sources of variability(38.6%–48.9%, 16.1%–17.3% and 13.2%–18.7% for soil and landscape, nutrient and pH, and yield variability, respectively), being either the best or second best approach. It was also found that the ROSE-YSTTS approach was effective in defining zones with high,medium and low economically optimum N rates. It is concluded that the integrated ROSE-YSTTS approach combining soil, landscape and yield spatial-temporal variability information can overcome the weaknesses of approaches using only soil, landscape or yield information,and is more robust for MZ delineation. It also has the potential for site-specific N management for improved economic returns. More studies are needed to further evaluate their appropriateness for precision N

关键词： economically optimum nitrogen rate fuzzy cluster analysis precision nitrogen management site-specific management soil landscape property yield map

Study on site-specific Nutrient Management in Cotton Field

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Agricultural Sciences in China 2001年第1期 102-106页

作者： YANG Li-ping JIANG Cheng JIN Ji-yun ZHANG Feng-ming Key Laboratory of Plant Nutrition Research of Ministry of Agriculture Soil and Fertilizer Institute of Chinese Academy of Agricultural Sciences Beijing 100081 Key Laboratory of Plant Nutrition Research of Ministry of Agriculture Soil and Fertilizer Institute of Chinese Academy of Agricultural Sciences Beijing 100081 Key Laboratory of Plant Nutrition Research of Ministry of Agriculture Soil and Fertilizer Institute of Chinese Academy of Agricultural Sciences Beijing 100081 Handan Agricultural Technology Extension Station Handan Hebei Province 056802

The study on the characteristics of spatial variability of soil nutrients and fertilizer recommendations in cotton field under certain conditions of agricultural management was conducted with GIS and systematic approach for soil nutrient constrains. The results showed that of the spatial variability of soil nutrient was greatly related to the management condition of previous crops. Grid sampling and variable rate application technology (VRAT) were the tools that would hopefully increase fertilizer efficiency. The fertilizers were applied where they were needed and at proper rate. Balance fertilization demonstration showed that fertilizer recommendations according to the available nutrient level in soil could decrease fertilizer cost with 657.4 yuan / ha and increase seed cotton yield by 19.8%. A net profit of the balanced fertilization was 5314.9 yuan / ha higher than that of local fertilization practice.

关键词： Cotton field site-specific nutrient management GIS Fertilizer recommendations Variable rate fertilization

Chemotactic Activity of site-specific Multivalent Conjugates of Stromal Cell-Derived Factor 1<i>α</i>on Branched Nanoparticles

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Journal of Biomaterials and Nanobiotechnology 2018年第1期9卷 51-63页

作者： Yu-Fang Hsieh Fang Huang Shyam Patel Song Li Department of Bioengineering and Medicine University of California Los Angeles (UCLA) Los Angeles CA USA

Stromal cell-derived factor 1α (SDF1α) is a potent chemokine for the recruitment of stem cells. A challenge is to maintain its activity and control its release. In this study, we engineered a recombinant cysteine-SDF1α (cysSDF1α) protein, and performed multivalent conjugation of cysSDF1 through the maleimide functional group to two forms of branched nanoparticles: multi-arm poly (ethylene glycol) (MA-PEG) and hyaluronic acid (HA). We characterized the chemotactic activity of the conjugates, and determined how the molecular weight (MW) of MA-PEG and HA affected the chemotactic activity. CysSDF1α had similar efficiency to wild-type SDF1α in cell recruitment. Multivalent conjugation of cysSDF1α to low MW MA-PEG (~18 nm) did not significantly affect the chemotactic activity, while the conjugation of cysSDF1α to high MW MA-PEG (~72 nm) lowered the efficiency, possibly due to the larger spacing between conjugated SDF1α molecules. HA has a linear backbone and a high density of multivalent binding sites;however, the chemotactic activity of HA-linked cys-SDF1α was much lower, which further decreased with the increase of HA MW from 200 kDa (~0.78 μm) to 700 kDa (~2.7 μm). Digestion of HA into smaller fragments using hyaluronidase partially recovered the chemotactic activity of cysSDF1α, suggesting that high MW HA might exert steric hindrance for SDF1α binding to its receptors on cell surface and that HA could be used as a depot for SDF1α storage and release. These results demonstrate that multivalent conjugates of SDF1α to nanoparticles may be used to engineer SDF1α delivery for cell recruitment and tissue regeneration.

关键词： SDF1α Delivery Cell Recruitment site-specific Protein Ligation Multivalent Protein Conjugates

Construction and screening of a multi-point site- specific mutant library of subtilisin E with a set of oligonucleotides

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Science China(Life Sciences) 1997年第4期40卷 337-344页

作者：肖谷田谢毅张婕孙筱清吴小舟陈小央王启松 State Key Laboratory of Genetic Engineering Institute of Genetics Fudan University Shanghai 200433 China

A mutant library of subtilisin E containing random combinations of various mutagenized sites wasconstructed by one-round mutagenesis with 15 mutagenic oligonucleotides. Mutants were screened through dot blot hybridization and DNA sequencing. A single-point mutant (Met 222Ala) and a three-point (Asn 76Asp/Asnl09Ser/ I le 205/Cys) mutant gene from the library were expressed. The mutant proteins exhibited conspicuously improved resistance to oxidation and heat treatment, as reported before. The results show that the library is reliable and very useful for protease subtilisin E engineering.

关键词： site-directed mutagenesis multi-point site-specific mutagenesis protein engineering subtilisin E.

Pharmacokinetic and pharmacodynamic evaluations of site-specific PEGylated exenatide analogs as long-acting glucoregulatory agents

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Pharmacokinetic and pharmacodynamic evaluations of site-spec...

中国药理学会第十次全国学术会议

作者： Michael Xu PegBio Co. Ltd.BioBay Building A3(Suite 417)218 Xinghu StreetIndustrial Park DistrictSuzhou Jiangsu 215125

Aim:Exenatide,the active ingredient of BYETTA(exenatide injection),is a synthetic 39-amino acid peptide originally isolated from the saliva of the gila monster that exhibits notable antidiabetic property and has been ... 详细信息

关键词： PEGylation site-specific Exenatide Diabetes Blood sugar Pharmacokinetics

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许钦松全世界的site-specific

花溪(艺术财经) 2015年第6期 68-69页

作者：高世現

在今年第56届威尼斯双年展"平行展"单元中,中国美协副主席、中国艺术研究院博士生导师、广东文联主席许钦松的"纯水墨"作品《岭云带雨》变身当代艺术装置作品,被布置成一个立体的"剧场":在墙上的原作正前方,策展人用透明材料制作了一个... 详细信息

在今年第56届威尼斯双年展"平行展"单元中,中国美协副主席、中国艺术研究院博士生导师、广东文联主席许钦松的"纯水墨"作品《岭云带雨》变身当代艺术装置作品,被布置成一个立体的"剧场":在墙上的原作正前方,策展人用透明材料制作了一个等大的布帘状复制品,并用鼓风机使帘上的笔墨线条流动起来,在作品画面上营造出一种朦胧、生动的东方文化意境。"我挂了白色的布帘,布帘后面是《岭云带雨》原作",许钦松对他的展览做了详细介绍,"鼓风机吹动这片布帘,让它们飘动起来,影像中的云的飘动,使之与我的画作相结合,将这一叠加的影像投射到布条上面。通过布条的空

关键词：许钦松全世界山水画 site-specific