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Expression,Purification,Characteristics and Homology Modeling of the HMGS from Streptococcus pneumoniae

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Biomedical and Environmental Sciences 2009年第3期22卷 229-236页

作者： YA-LI ben gu-ZHEN CUI CHEN LI RUI HAN j.E ZHANG QING-YE ZHANG j.AN WAN DE-LI LIU College of Life Science Central China Normal University Wuhan 430079 Hubei China Key Laboratory of Pesticide & Chemical Biology (CCNU) of Ministry of Education Wuhan 430079 Hubei China j.anghan University Wuhan 430016 Hubei China

Obj.ctive To understand the molecular basis for a potential reaction mechanism and develop novel antibiotics with homology modeling for 3-hydroxy-3-methylglutaryl coenzyme A （HMG-CoA） synthase （HMGS）. Methods The genetic engineering technology and the composer module of SYBYL7.0 program were used, while the HMGS three-dimensional structure was analyzed by homology modeling. Results The mvaS gene was cloned from Streptococcus pneumoniae and overexpressed in Escherichia coli from a pET28 vector. The expressed enzyme （about 46 kDa） was purified by affinity chromatography with a specific activity of 3.24 μmol/min/mg. Optimal conditions were pH 9.75 and 10 mmol/L MgCl2 at 37 ℃ The Vmax and Km were 4.69 μmol/min/mg and 213 μmol/L respectively. The 3D model of *** HMGS was established based on structure template of HMGS of Enterococcus faecalis. Conelusion The structure of HMGS will facilitate the structure-based design of alternative drugs to cholesterol-lowering therapies or to novel antibiotics to the Gram-positive cocci, whereas the recombinant HMGS will prove useful for drug development against a different enzyme in the mevalonate pathway.

关键词： Streptococcus pneumoniae HMG-CoA synthase Analysis of dynamics Homology modeling

Structural insights into the CRISPR-Cas-associated ribonuclease activity of Staphylococcus epidermidis Csm3 and Csm6: a step for the development of novel genome editing tool

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Science Bulletin 2018年第11期63卷 672-674页

作者： Feng gu School of Ophthalmology and Optometry Eye Hospital Wenzhou Medical University State Key Laboratory Cultivation Base and Key Laboratory of Vision Science Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry

CRISPR-Cas systems has been developed as genome editing tools,which are originally discovered as sequence-specific defense system utilized by bacteria and archaea to fight with the invasion by foreign nucleic acids such as phages or *** to the current classification groups of CRISPR-Cas system,Type I,Type III and Type IV comprise the Class 1 systems for their function through multisubunit Cas protein complex to interference the targeted nucleic *** contrast,Class 2 systems,consisting of

关键词：编辑工具染色体葡萄球菌结构防卫系统噬菌体

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Surface and optical properties of silicon nitride deposited by inductively coupled plasma-chemical vapor deposition

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j.urnal of Semiconductors 2018年第8期39卷 36-40页

作者： Yi Zhu Xingyou Chen Yingj.e Ma Yonggang Zhang ben Du Yanhui Shi Yi gu State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences Shanghai 200050 China University of Chinese Academy of Sciences Beijing 100049 China

The surface and optical properties of silicon nitride samples with different compositions were investigated. The samples were deposited on In P by inductively coupled plasma chemical vapor deposition using different NH3flow rates. Atomic force microscopy measurements show that the surface roughness is increased for the samples with both low and high NH3flow rates. By optimization, when the NH3flow rate is 6 sccm, a smooth surface with RMS roughness of 0.74 nm over a 5 × 5 μm2area has been achieved. X-ray photoelectron spectroscopy measurements reveal the Si/N ratio of the samples as a function of NH3flow rate. It is found that amorphous silicon is dominant in the samples with low NH3flow rates, which is also proved in Raman measurements. The bonding energies of the Si and N atoms have been extracted and analyzed. Results show that the bonding states of Si atoms transfer from Si0to Si+4as the NH3flow rate increases.

关键词： silicon nitride ICPCVD X-ray photoelectron spectroscopy Raman

GoldCLIP： Gel-omitted Ligation-dependent CLIP

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Genomics, Proteomics & Bioinformatics 2018年第2期16卷 136-143页

作者： j.aqi gu Ming Wang Yang Yang Ding Qiu Yiqun Zhang j.nbiao Ma Yu Zhou Gregory j. Hannon Yang Yu State Key Laboratory of Genetic Engineering Department of Biochemistry School of Life Sciences Fudan University Shanghai 200438 China CAS Key Laboratory of RNA Biology Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China Hubei Key Laboratory of Cell Homeostasis College of Life Sciences Wuhan University Wuhan 430072 China Cancer Research UK Li Ka Shing Centre University of Cambridge Cambridge CB2 ORE United Kingdom

Protein-RNA interaction networks are essential to understand gene regulation control. Identifying binding sites of RNA-binding proteins （RBPs） by the UV-crosslinking and immunoprecipitation （CLIP） represents one of the most powerful methods to map protein RNA interactions in vivo. However, the traditional CLIP protocol is technically challenging, which requires radioactive labeling and suffers from material loss during PAGE-membrane transfer procedures. Here we introduce a super-efficient CLIP method （GoldCLIP） that omits all gel purification steps. This nonisotopic method allows us to perform highly reproducible CLIP experiments with polypyrimidine tract-binding protein （PTB）, a classical RBP in human cell lines. In principle, our method guarantees sequencing library constructions, providing the protein of interest can be successfully crosslinked to RNAs in living cells. GoldCLIP is readily applicable to diverse proteins to uncover their endogenous RNA targets.

关键词： RNA binding protein UV crosslinking CLIP HaloTag PTB

Development and validation of abiotic ligand model for nickel toxicity to wheat(Triticum aestivum)

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j.urnal of Environmental Sciences 2017年第12期29卷 22-30页

作者： Yang j.ang Xueyuan gu Boj.ng Zhu Cheng gu State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China.

A terrestrial biotic ligand model（t-BLM） was developed to predict nickel toxicity to wheat（Triticum aestivum） root elongation in hydroponic solutions. The competitive effects of five maj.r cations（Ca^（2＋）, Mg^（2＋）, Na~＋, K~＋and H~＋） on Ni toxicity were investigated and Mg^（2＋）was found to be a strong competitor, while H＋showed less competing effect. Besides free Ni^（2＋）,the toxicity induced by the species NiHCO_3~＋ was non-neglect able at pH 〉 7 because NiHCO_3~＋ occupied a significant fraction of total Ni under such condition. Thus, a t-BLM including Ni^（2＋）, NiHCO_3~＋, Mg^（2＋）, and H＋could successfully predict the nickel toxicity to wheat root elongation and it performed better prediction than the conventional free ion activity *** addition, the model was examined with two sets of independent experiments, which contained multiple cations and low-molecular-weight organic acids to mimic the rhizosphere condition. The developed t-BLM well predicted nickel toxicity in both experiments since it can account in both complexation and competition effects, suggesting its potential to be used in a complicated matrix like soil solution. This study provides direct evidence that the t-BLM is a reliable method for the risk assessment of nickel in terrestrial system.

关键词： Model Nickel Wheat Toxicity Risk assessment

Experimental study of the effects of a transversal air-flow deflector in electronics air-cooling

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j.urnal of Thermal Science 2011年第1期20卷 76-81页

作者： M.REBAY A.ARFAOUI j.PADET R.ben MAAD Université de Reims GRESPI/lab.de ThermomécaniqueFaculté des sciencesBP 103951687 ReimsFrance Laboratoire d'Energétique et Transferts Thermique et Massique Faculté des sciences2092 Manar IITunisia

This paper presents an experimental investigation of the influence of a transversal flow deflector on the cooling of a heated block mounted on a flat *** deflector is inclined and therefore it guides the air flow to the upper surface of the *** configuration is simulating the air-cooling of a rectangular integrated circuit or a current converter mounted on an electronic *** electronic component is assumed dissipating low heat power,as such,air forced convection is still a sufficient cooling way even without fan or heat sink on the *** measurements are given by hot and cold wires anemometers and by an InfraRed *** results give details of the effects of the deflection on the hydrodynamic and the thermal fields on and over the block for different inclination *** show that the deviation caused by the deflector may significantly enhance the heat transfer from the *** is also able to avoid local overheating of the electronic *** heat transfer rate and homogenised temperature are shown to be obtained with an inclination angle =30°.

关键词： Electronic cooling infrared imaging hot wire anemometer upward facing step backward facing step

Zircon U-Pb dating and geochemical study of the Xianggou granite in the Ma'anqiao gold deposit and its relationship with gold mineralization

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Science China Earth Sciences 2010年第2期53卷 220-240页

作者： LEE ben State Key Laboratory of Continental Dynamics Department of GeologyNorthwest University

Single zircon LA-ICP-MS U-Pb dating and lithogeochemical studies have been performed on the Xianggou monzonitic granitic porphyry outcropped in the Ma’anqiao gold deposit.A weighted average U-Pb age of 242.0±0.8 Ma for Xianggou monzonitic porphyry has been *** corresponds with the conclusions of previous studies indicating a syn-orogenic age (242±21 Ma) of the Qinling Orogenic Belt,suggesting that the formation of the Xianggou granite should be associated with the collisional event of the North China Plate and the Yangtze Plate in the Indosinian *** Xianggou granite is characterized by the high silicon and alkali of high K calc-alkaline series *** is rich in Al (Al2O3=14.49%-15.61%) and Sr (457.10-630.82 ppm),poor in Y (<16 ppm) and HREE (Yb<0.45 ppm),and exhibits high ratios of Sr/Y (76.24-97.34) and (La/Yb)N (29.65-46.10),as well as strongly fractionated REE *** geochemical characteristics suggest the Xianggou granite can be classified as C-type adakitic *** initial Sr isotope ratios for the Xianggou granite vary from 0.70642 to 0.70668,εNd(t) values from -4.54 to -3.98,and TDM values from 1152 Ma to 1220 *** low εNd(t) and ISr and high TDM values,as well as Na2O/K2O ratios of the Xianggou granite are close to 1 (Na2O/K2O=0.95-1.10),indicating that it is not an I-type adakite formed by partial melting of the subducting oceanic crust,nor adakitic rock formed by melting of the underplated basaltic lower crust,but the product of partial melting of the nonunderplated basaltic thickened lower *** from the Xianggou pluton have a homogeneous Hf isotopic composition with negative εHf(t) values (between -9.7 and -5.9,with an average of -6.9),indicating that the rock-forming materials were mostly extracted from the ancient crust,not from the depleted *** Xianggou monzonitic granitic porphyry is rich in LILE and LREE and depleted in HSFE,HREE and Y;the composition of trace element and REE are similar to those

关键词： zircon U-Pb dating Xianggou monzonitic granitic porphyry Carlin type and Carlin-like type gold deposits petrologenic and metallogenic dynamic background

Rapid Determination of Ranitidine in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry and Its Application to a Clinical Pharmacokinetic Study

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Chemical Research in Chinese Universities 2010年第6期26卷 910-914页

作者： ZHANG Chao WANG Lu guAN Xin j. Paul Fawcett ZHAO Li-mei SUN Yan-tong gu j.ng-kai Research Center for Drug Metabolism College of Life Science Jilin University Changchun 130021 P R. China Liaoning Province Academy of Analytic Science Shenyang 110015 P. R. China School of Pharmacy University of Otago PO Box 56 Dunedin New Zealand Second Clinical Hospital Affiliated to the Chinese Medical University Shenyang 110004 P. R. China

A rapid and sensitive assay based on high performance liquid chromatography-tandem mass spectrometry（LC-MS/MS） was developed for the determination of ranitidine（RAN） in human plasma with codeine as internal standard（IS）.After protein precipitation with acetonitrile,the analyte and IS were separated on a Zorbax SB-Aq C18 column（150 mm×4.6 mm i.d.,5 μm） eluted with a mobile phase consisting of methanol/acetonitrile/10 mmol/L ammonium acetate containing 1% formic acid（pH=2.4）（volume ratio 12.5：12.5：75） at a flow rate of 1.0 mL/*** was performed by electrospray ionization in the positive ion mode followed by the multiple reaction monito-ring（MRM） of the transitions of RAN at m/z 315.1→176.3 and of IS at m/z 300.1→*** method was linear over a concentration range of 1―1000 ng/mL（r=0.9991） with a lower limit of quantitation（LLOQ） of 1 ng/mL and a limit of detection（LOD） of 0.3 ng/*** as relative error was from-0.01% to-1.7% and intra-day and inter-day precisions as relative standard deviation were ≤8.9% and ≤5.5%,*** method was successfully applied to a pharmacokinetic study of ranitidine,getting a single oral dose（160 mg） to healthy volunteers.

关键词： Ranitidine Pharmacokinetics Human plasma Protein precipitation LC-MS/MS

Aggregation-induced emission luminogen for specific identification of malignant tumour in vivo

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Science China Chemistry 2020年第3期63卷 393-397页

作者： j.anlei Shen Kun Tao Peilin gu Chen gui Dong Wang Zhenyu Tan Lihua Wang Zhiming Wang Anj.n Qin ben Zhong Tang Shisan Bao School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Tongren Hospital School of MedicineShanghai Jiao Tong UniversityShanghai 200240China Discipline of Pathology Bosch Institute and School of Medical SciencesCharles Perkins CentreThe University of SydneyAustralia Division of Physical Biology CAS Key Laboratory of Interfacial Physics and TechnologyShanghai Synchrotron Radiation FacilityShanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China Department of Chemistry HKUST Jockey Club Institute for Advanced StudyInstitute of Molecular Functional MaterialsDivision of Biomedical EngineeringState Key Laboratory of Molecular NeuroscienceDivision of Life ScienceThe Hong Kong University of Science and TechnologyHong KongChina State Key Laboratory of Luminescent Materials and Devices South China University of TechnologyGuangzhou 510640China

Colorectal cancer(CRC)is still a maj.r killer,mainly due to the lack of early detection biomarker with sensitivity/*** histopathology is the gold standard approach in practice,but there are still some issues(false diagnosis and long waiting period).Aggregation-induced emission(AIE)is a novel photophysical phenomenon which has been widely utilized for biological imaging in vitro,including malignant cells,showing remarkable imaging contrast and enhanced emission in high concentrated ***,it is unclear if AIE dyes can identify malignant cells specifically in vivo.A great challenge for specific labeling of malignant cells is probably ascribed to the complex compositions in tumor ***,an AIE dye-based mitochondria-targeted histological staining strategy was employed to localize cancer and the metastatic track in the fresh colorectal *** novel approach holds great potential to revolutionize the clinical diagnosis and intervention for devastating malignancy.

关键词： aggregation-induced emission histological staining colorectal cancer