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Search Results: 1 - 10 of 66604 matches for " SU Zhi-guo "
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Studies of the Mechanism of 7-epi-taxol Converted to Taxol from Taxus Extract Catalyzed with Al2O3

ZHANG Zhi-Qiang,SU Zhi-guo,

生物工程学报 , 2000,
Abstract: 在碱性氧化铝作用下,云南红豆杉浸膏中7-表-紫杉醇被催化转化为紫杉醇。该异构化反应是由氧化铝表面L酸中心、碱中心的协同作用而催化,在室温条件下就可进行,氧化铝表面酸碱中心的种类和强度都将影响反应进行的程度,适量的甲醇对反应有促进作用。
Separation and Purification of Taxol Using Normal-and Reversed-phase Chromatography in Tandem

ZHANG Zhi-qiang,SU Zhi-guo,

生物工程学报 , 2000,
Abstract: A method is described for separation and purification of taxol from the extract of Tascus cuspidate callus cul-ture with Al2O3 normal-phase chromatography and C18 reversed-phase chromatography, The operating conditions of the two chromatographic steps were investigated and optimized. The content of taxol was greatly increased after Al2O3 chro-matography. The purity of taxol reached 95 % from less than 1.0 % after the two chromatographic steps. The final purity of taxol was more than 98% after the process of crystallization. The 13CNMR spectrum of the product was identical to that of taxol reported in the literature.
Purification and Fingerprinting Development of Salvia miltiorrhiza Bunge by High-speed Counter-current Chromatography

GU Ming,OUYANG Fan,SU Zhi-Guo,

生物工程学报 , 2003,
Abstract: In an attempt to apply high-speed counter-current chromatography HSCCC for TCM fingerprints, the separation and purification of the Chinese medicinal plant Salvia miltiorrhiza Bunge of different localities was realized using the technique. The equipments used include a HSCCC (TBE-300) of Shenzhen Tauto Biotech containing three connected preparative coils (diameter of tube = 2.6mm, total volume = 300mL) and a 20mL sample loop and a HPLC from Shimadzu of Japan with a Ultrasphere C18 column (150 x 4.6mm ID, 5microm) and a 20microL sample loop. Salvia miltiorrhiza Bunge samples from 3 locations were separated by HSCCC in a Step-wise elution program with solvent systems A (hexane:ethanol: water = 10:5.5:4.5) and B (hexane:ethanol: water = 10:7:3) at a speed of 900 r/min and a flow-rate of 2mL/min. All the 12 peak fractions were eluted within 13 hours. The contents of each component varied greatly in different samples, which confirmed previous observation that the locations and climates have a great impact on the TCM quality and also indicated a quality control system is necessary to safeguard the quality of the herb. The retention times of the 12 peak fractions from crude extracts of the samples were collected by HPLC and the absorption spectrums of the corresponding peaks were identified. The 12 components of the three crude samples were readily distinguishable and can be used as fingerprints of S. miltiorrhiza Bunge. The relative standard deviation of the HSCCC retention times was less than 3%, which satisfies the requirement of the national standard reference index. The components 7, 8 and 11 from the standards were identified to be crypototanshinone, tanshinone I and tanshinone II A respectively. This study demonstrates that if it is possible to apply HSCCC for TCM fingerprinting, especially with samples of high viscosity and highly absorptive components. The precision and the run time of fingerprinting can be further improved if larger volume and a temperature control system is used. With these and other improvements, HSCCC is expected to play an important role in TCM development.
Progress in putification of Human Serum Albumin

LU Xiu-Ling,SU Zhi-Guo,

生物工程学报 , 2002,
Abstract: Human serum albumin(HSA) has been used clinically to treat a number of diseases with high dosage. Extremely pure puoduct is required in large-scale production. Plasma-derived HSA(pHSA) has long been produced by precipitation methods. Among them cold ethanol precipitation is dominant. However, chromatographic purification of HSA has been increasingly studied in the last few years. Application of chromatography, especially ionexchange, affinity, and size-exclusion, has opened a new area in the production of pHSA. A new challenge is the purification of recombinant HSA(rHSA). A successful approach involves STREAMLINE expanded bed adsorption to direct capture the target product from the fermentation broth. This novel process eliminates the need to separate the cells by centrifugation or membrane filtration. Ion exchange chromatography and hydrophobic chromatography play a central role in the purification scheme. Integration with other chromatographic techniques such as size-exclusion, metal chelate, and affinity gives improved purification results. Though innovative, the purification of rHSA still needs further improvement and optimization to increase product purity and process recovery.
Preparation of 2-Chlorotritylchloride Resin and Its Application in Solid Phase Peptide Synthesis

LI Peng,LIANG Hong,ZHANG Jing,SU Zhi-guo,

过程工程学报 , 2009,
Abstract: 以2.氯二苯甲酮为原料,与PCI5在130-140℃下加热合成1.氯.2.二氯苯甲基苯作为前体,与粒径小于30 pm的1.5%二乙烯苯交联聚苯乙烯树脂进行Friedel-Crafls烷基化反应,所得2.氯三苯甲基醇用亚硫酰氯进行氯化处理,得到2.氯三苯甲基氯树脂.该制备方法简便易行且无需使用有机金属试剂,所得2-氯三苯甲基氯树脂旨位氨基酸上载率和溶胀性质均优于同类树脂商品,使用该树脂合成的困难序列酰基载体蛋白65.74的固相合成收率为72%,产物纯度达到76.5%.
Preparation of Macroporous Polymer Microspheres by Double-emulsion Method

SONG Wei,MA Guang-hui,SU Zhi-guo,

过程工程学报 , 2007,
Abstract: 研究在不使用乳化剂和致孔剂的条件下采用两亲性聚合物单甲氧基聚乙二醇聚乳酸共聚物制备大孔微球,确定了形成大孔结构的必要条件及孔径的控制方法,并对大孔微球的形成机理进行了探讨.结果表明,两亲性聚合物单甲氧基聚乙二醇聚乳酸共聚物能较好地稳定乳液进而形成贯穿孔结构,而选用疏水性聚合物聚乳酸和聚(乳酸-羟基乙酸)时只能制备出单腔室结构的微球;当内水相与油相体积比在1:4~1:2、油相溶剂去除分两步时,能形成孔径在100 nm以上的大孔聚合物微球,大孔微球的孔径随着初乳化速率的增大而减小.
Preparation and Characterization of Polystyrene Support for Solid Phase Organic Synthesis of RNA

LIANG Hong,LI peng,ZHANG Jing,SU Zhi-guo,

过程工程学报 , 2009,
Abstract: 将氨甲基衍生的聚苯乙烯载体与3-氨基-1-(4,4'-二甲氧三苯甲基)-1,2-丙二醇通过琥珀酸键连接,成功制备了一种新型的通用型RNA固相有机合成载体.载体有效载量达61~92μmol/g,高于传统可控孔度玻璃(CPG)载体;载体偶联效率大于95%,与CPG载体相似;RNA产物合成后处理条件温和.反相高效液相色谱显示自制载体合成产物与CPG载体合成产物具有同一性,没有明显降解现象发生.这种聚苯乙烯基质RNA固相有机合成载体由于其高载量、通用性及较好的合成性能等优点,具有替代传统CPG载体的潜力.
Optical characteristic and gap states distribution of amorphous SnO2:(Zn,In) film

Zhang Zhi-Guo,

中国物理 B , 2010,
Abstract: In this paper the fabrication technique of amorphous SnO2:(Zn,In) film is presented. The transmittance and gap-states distribution of the film are given. The experimental results of gap-states distribution are compared with the calculated results by using the facts of short range order and lattice vacancy defect of the gap states theory. The distribution of gap state has been proved to be discontinuous due to the short-range order of amorphous structure.
Recent Research Progress in Biogas Fermentation Process

CHENG Xi-yu,ZHUANG Guo-qiang,SU Zhi-guo,LIU Chun-zhao,

过程工程学报 , 2008,
Abstract: 综述了沼气发酵菌群、工艺控制和处理系统方面的研究进展,指出对发酵机理缺乏了解是导致过程不稳和效率不高的主要原因,提出将来的研究重点应通过元基因组手段解析菌群相互作用和代谢网络,建立基于反应器操作、VFAs代谢、活性茵群变化和功能基因表达的多尺度过程控制手段,以及发展原料预处理、科学配伍和两相联产氢气甲烷等工艺来提高系统效率.
Theoretical study on electric-pulse-induced resistance change in perovskite Pr1-x, Cax MnO3 films

Li Qian,Wang Zhi-Guo,Liu Su,Xing Zhong-Wen,Liu Mei,
李 倩
,王之国,刘 甦,邢钟文,刘 楣

物理学报 , 2007,
Abstract: We developed a effective tunneling model to study the electric-pulse-induced resistive switching (EPIR) effect in PCMO films, and find that the tunneling probability of the charge transport at interfaces plays an important role in the EPIR effect. We also study the nonvolatile characteristics and the hysteretic current-voltage curve in the PCMO films, the calculated results consistent with the recent experimental data. This electric-pulse- induced resistive switching effect at room temperate has excellent potential of application.
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