Youqi Tang

Peking University, Peping, Beijing, China

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Publications (87)203.79 Total impact

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    ABSTRACT: We have studied the surface morphology, photoluminescence (PL), Raman spectra and optical absorption of the porous silicon (PS) samples prepared under supercritical drying (SD) and natural drying (ND) process. The experimental results of scan electron microphotograph and Raman spectra show that there are obvious differences in microstructure between the SD and ND samples. No crack of the skeleton has been found in the SD sample, but the skeleton of the ND sample has heavily destroyed. Besides, the PL and absorption spectra of the SD sample are not the same as those of the ND sample.
    Chinese Science Bulletin 04/2012; 45(9):814-818. DOI:10.1007/BF02887409 · 1.37 Impact Factor
  • Jiansuo Wang, Luhua Lai, Youqi Tang
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    ABSTRACT: The toxic chemicals from the database Registry of Toxic Effects of Chemical Substances (RTECS) were analyzed by structural similarity comparison, which shows that the structure patterns or characteristics of toxic chemicals exist in a sufficiently large database. Then, a two-step strategy was proposed to explore noncongeneric toxic chemicals in the database: the screening of structure patterns by similarity comparison and the derivation of detailed relationship between structure and activity by using comparative molecular field analysis (CoMFA) of Quantitative Structure-Activity Relationship (QSAR) technologies. From the performance of the procedure, such a stepwise scheme is demonstrated to be feasible and effective to mine a database of toxic chemicals. It can be anticipated that database mining of toxic chemicals will be a new area for predictive toxicology of chemicals.
    Chinese Science Bulletin 04/2012; 45(12):1093-1097. DOI:10.1007/BF02887181 · 1.37 Impact Factor
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    ABSTRACT: The structure of acetamidase/formamidase (Amds/Fmds) from the archaeon Thermoanaerobacter tengcongensis has been determined by X-ray diffraction analysis using MAD data in a crystal of space group P2₁, with unit-cell parameters a = 41.23 (3), b = 152.88 (6), c = 100.26 (7) Å, β = 99.49 (3) ° and been refined to a crystallographic R-factor of 17.4% and R-free of 23.7%. It contains two dimers in one asymmetric unit, in which native Amds/Fmds (TE19) contains of the 32 kDa native protein. The final model consists of 4 monomer (299 amino acids residues with additional 2 expression tag amino acids residues), 5 Ca²⁺, 4 Zn²⁺ and 853 water molecules. The monomer is composed by the following: an N-domain which is featuring by three-layers β/β/β; a prominent excursion between N-terminal end of strand β₇ and β₁₁, which contains four-stranded antiparallel β sheet; an C-domain which is formed by the last 82 amino acid residues with the feature of mixed α/β structure. The protein contains ion-pair Ca²⁺-Zn²⁺. The portion of three-layer β/β/β along with the loops provides four protein ligands to the tightly bound Ca²⁺, three water molecules complete the coordination; and provides five protein ligands to the tightly bound Zn²⁺, one water molecule complete the coordination.
    The Protein Journal 12/2011; 31(2):166-74. DOI:10.1007/s10930-011-9387-0 · 1.04 Impact Factor
  • ChemInform 12/2010; 33(48). DOI:10.1002/chin.200248217
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 06/2010; 31(26). DOI:10.1002/chin.200026245
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    ABSTRACT: The solubility and stability of platinum-based anticancer agents have a direct bearing on their activity and toxicity. Much research has been conducted over the past decades in order to prepare drugs such as cisplatin and carboplatin with improved efficacy and reduced toxicity. Based on the premise that supramolecular platinum agents may have superior physicochemical properties, we successfully designed a novel anticancer agent, dicycloplatin, which has proven to be active against a number of human malignancies. The crystal structure of dicycloplatin has been determined. An aqueous solution of dicycloplatin was also studied using electrospray ionization mass spectrometry (ESI-MS). Based on the experimental observations, a model of the structure in aqueous solution is proposed which explains both the higher solubility and higher stability of dicycloplatin compared with carboplatin.
    Science China-Chemistry 06/2010; 53(6):1346-1351. DOI:10.1007/s11426-010-3184-z · 1.52 Impact Factor
  • Jiansuo Wang, Luhua Lai, Youqi Tang
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 03/2010; 31(9). DOI:10.1002/chin.200009235
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    ABSTRACT: This work discusses the preparation of small metal nanoclusters stabilized with glycol and OH−1, which are attractable building blocks for the fabrication of new heterogeneous catalyst. New Os and Pt/Rh bimetallic nanoclusters with small particle size and narrow size distribution have been prepared by the polyol synthesis method and characterized by TEM, EDX, XRD and XPS. Superior catalytic properties for the selective hydrogenation of chloronitrobenzene over the nanocomposite catalysts composed of metal nanocluters and inorganic semiconductor nanoparticles have been discussed.
    Topics in Catalysis 05/2005; 35(1):35-41. DOI:10.1007/s11244-005-3811-7 · 2.22 Impact Factor
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    ABSTRACT: No crystal structures are yet available for homologues of a predicted acetamidase/formamidase (Amds/Fmds) from the archaeon Thermoanaerobacter tengcongensis. The Amds/Fmds gene was cloned and expressed as a soluble protein in Escherichia coli. Native Amds/Fmds and its SeMet-substituted form were purified and crystallized by vapour diffusion in hanging drops at 296 K. The native crystals, which were grown in PEG 8000, belong to the monoclinic space group P2(1), with unit-cell parameters a = 41.23 (3), b = 152.88 (6), c = 100.26 (7) A, beta = 99.49 (3) degrees. The diffraction data were collected to 2.00 A resolution using synchrotron radiation. Based on a predicted solvent content of 50%, a Matthews coefficient of 2.44 A3 Da(-1) and two main peaks in the self-rotation function, the asymmetric unit is predicted to contain two dimers of the 32 kDa native protein. MAD data were collected for the SeMet protein, but the corresponding crystals display different unit-cell parameters and appear to contain four dimers in the asymmetric unit.
    Acta Crystallographica Section F Structural Biology and Crystallization Communications 02/2005; 61(Pt 1):106-8. DOI:10.1107/S1744309104030519 · 0.57 Impact Factor
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    ABSTRACT: The putative metal-dependent hydrolase gene TTE1006 from Thermoanaerobacter tengcongensis strain MB4T (T = type strain; Genbank accession No. AE008691) was heterologously expressed in Escherichia coli. The 205-amino-acid gene product was purified and crystallized. The crystal used for data collection belongs to space group P2(1), with unit-cell parameters a = 85.2, b = 62.1, c = 172.4 A, beta = 104.2 degrees. Using a synchrotron-radiation source, the resolution limit of the data reached 1.87 A. Eight molecules were estimated to be present in the asymmetric unit, with a solvent content of 48%. Structure determination is ongoing using the multiple-wavelength anomalous diffraction (MAD) method and also the molecular-replacement (MR) method.
    Acta Crystallographica Section F Structural Biology and Crystallization Communications 02/2005; 61(Pt 1):90-2. DOI:10.1107/S1744309104029392 · 0.57 Impact Factor
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    ABSTRACT: Alpha-insect scorpion toxins are a distinct group of scorpion neurotoxins for which no crystal structures are yet available. A novel alpha-insect toxin named BmKalphaIT1 from the scorpion Buthus martensii Karsch (BmK) has been expressed as an inclusion body in Escherichia coli and purified by chromatography after renaturation. Recombinant BmKalphaIT1 (rBmKaIT1) was crystallized using the vapour-diffusion technique in hanging drops at 296 K. The crystals, which were grown in sodium phosphate, belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 30.24 (1), b = 36.51 (3), c = 57.08 (2) A. Diffraction data were collected to 2.1 A resolution using synchrotron radiation. There appears to be one rBmKalphaIT1 molecule in the asymmetric unit.
    Acta Crystallographica Section D Biological Crystallography 10/2003; 59(Pt 9):1635-6. · 7.23 Impact Factor
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    ABSTRACT: α-Insect scorpion toxins are a distinct group of scorpion neurotoxins for which no crystal structures are yet available. A novel α-­insect toxin named BmKαIT1 from the scorpion Buthus martensii Karsch (BmK) has been expressed as an inclusion body in Escherichia coli and purified by chromatography after renaturation. Recombinant BmKαIT1 (rBmKaIT1) was crystallized using the vapour-diffusion technique in hanging drops at 296 K. The crystals, which were grown in sodium phosphate, belonged to the orthorhombic space group P212121, with unit-cell parameters a = 30.24 (1), b = 36.51 (3), c = 57.08 (2) Å. Diffraction data were collected to 2.1 Å resolution using synchrotron radiation. There appears to be one rBmKαIT1 molecule in the asymmetric unit.
    Acta Crystallographica Section D Biological Crystallography 09/2003; 59(9):1635-1636. DOI:10.1107/S090744490301415X · 7.23 Impact Factor
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    ABSTRACT: This Letter describes an electrochemical route for deposition of Ag7Te4. Thin films of Ag7Te4 were electrodeposited on ITO substrates at −0.65 V (vs Ag/AgCl) from DMSO solutions containing 0.1 M NaNO3, 5.0 mM AgNO3, and 7.5 mM TeCl4. The deposited film consists of triangles characteristic of a (1 1 1) single-crystal with a hexagonal structure. Highly ordered and single-crystalline Ag7Te4 nanowire arrays were synthesized by this electrodeposition approach, in conjunction with template synthesis technique.
    Chemical Physics Letters 08/2003; 377(1-2):205-209. DOI:10.1016/S0009-2614(03)01075-3 · 1.99 Impact Factor
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    ABSTRACT: Electrochemically induced sot-gel deposition has been used to generate one-dimensional silica nanostructures, such as nanotube, "bamboo-like" structure and nanowire. The deposition was carried out in the pores of the anodic alumina membrane from a mixed tetraethoxysilane (TEOS), ethanol and 0.3 M KNO3 aqueous solution in a potential range between -0.95 and -1.25 V. We demonstrated that the growth of these nanostructures is strongly dominated by the electrochemical process. (C) 2003 Published by Elsevier B.V.
    Electrochemistry Communications 08/2003; 5(8-5):673-676. DOI:10.1016/S1388-2481(03)00149-8 · 4.29 Impact Factor
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    ABSTRACT: Colloidal solutions of thin platinum nanowires having lengths of 10 to 70 nm and diameters of 1.5–3 nm were prepared by reducing K2PtCl4 with hydrogen in a glycol solution containing K2C2O4 and preformed Pt seeds. TEM, HRTEM, XRD and UV-Vis absorption spectroscopy were used to study the structure of the obtained nanowires and the effect of preparation conditions, such as pH value, temperature, preformed Pt nanoseeds and stabilizing agents, on the morphology of the products. The mechanism for forming the thin Pt nanowires in the absence of a 1D structure template was discussed based on the experimental results. Stable colloidal solutions of mercaptan-modified Pt nanowires were prepared for the first time by transferring the prepared thin Pt nanowires into toluene containing octadecylmercaptan.
    Journal of Materials Chemistry 01/2003; 13(5):1192-1195. DOI:10.1039/b211747a · 6.63 Impact Factor
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    ABSTRACT: A new highly selective hydrogen sensor based on TiO2/PtO−Pt dual-layer films has been prepared. At 180−200 °C, the prepared nanostructured sensor exhibits an excellent selectivity and good sensitivity to H2 in air but is immune to many other kinds of reductive gases such as CO, NH3, and CH4. The sensor can give a faithful response to 1% H2 in air, while the limitation for detecting H2 in nitrogen is less than 1000 ppm. Influences of operation temperature and humidity on the sensing performance of the sensor were also investigated. The mechanism of the present sensor was attributed to the partial reduction of Ti4+ to Ti3+ by hydrogen catalyzed by a thin film of surface-oxidized Pt nanoparticles.
    ChemInform 08/2002; 33(48). DOI:10.1021/cm0201293
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    ABSTRACT: Highly ordered TiO2 single-crystalline nanowire arrays have been fabricated within the pores of anodic aluminum oxide (AAO) template by a cathodically induced sol−gel method. Raman spectra confirmed that the nanowires are composed of pure anatase TiO2. TEM investigations indicated that these nanowires have a uniform tetragonal single-crystal structure. Finally, a possible growth mechanism of the TiO2 nanowires is discussed.
    Nano Letters 07/2002; 2(7):717-720. DOI:10.1021/nl025541w · 12.94 Impact Factor
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    ABSTRACT: Highly ordered CdTe nanowire arrays were prepared by electrochemical deposition into the pores of anodic aluminum oxide templates from an ethylene glycol bath containing CdCl2, TeCl4, and KI. Electron microscopy results showed that the length, diameter, and direction of growth of the nanowires were quite uniform. X-ray diffraction, transmission electron microscopy, and high-resolution electron microscopy investigations showed that these nanowires had a crystalline structure of hexagonal CdTe single crystal with a uniform [001] growth direction.
    06/2002; 17(07):1711 - 1714. DOI:10.1557/JMR.2002.0253
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    ABSTRACT: Using oxalate as a stabilizing agent, stable colloidal solutions of platinum nanoparticles of different shape distributions were prepared by reducing K2[Pt(C2O4)2], K2PtCl6, or K2PtCl4 with hydrogen. The mean diameters of the Pt nanoparticles prepared from these precursors are 6.5, 3.5, and 7.9 nm, respectively. UV−vis absorption spectroscopy and transmission electron microscopy studies on the preparation processes and the products indicate that not only the rate of reduction and particle size but also the shape distributions of the prepared Pt nanoparticles depend on the used precursors. The reduction of K2[Pt(C2O4)2] in water at room temperature is quite slow, while adding suitable amounts of CaCl2 or increasing temperature can accelerate the reduction process. Pt nanoparticles prepared from K2[Pt(C2O4)2] have quite narrow size and shape distributions, and the selectivity of cubic nanoparticles is greater than 90%. Adding CaCl2 in the reaction system does not obviously affect the size and shape distributions of the prepared nanoparticles. Oxalate-stabilized Pt colloid is sensitive toward oxygen; during aging in air, oxidation decomposition of oxalate is catalyzed by the Pt nanoparticles, which leads the Pt nanoparticles to aggregate into linear aggregations. After exposure to air for long times and treatment with hydrogen, these linear aggregations transform into Pt nanowires.
    Langmuir 05/2002; 18(12). DOI:10.1021/la020087x · 4.38 Impact Factor
  • Organometallics 04/2002; 7(1). DOI:10.1021/om00091a005 · 4.25 Impact Factor

Publication Stats

2k Citations
203.79 Total Impact Points

Institutions

  • 1987–2012
    • Peking University
      • • State Key Laboratory for Structural Chemistry of Unstable and Stable Species
      • • College of Chemistry and Molecular Engineering
      • • Department of Chemical Biology
      • • Department of Chemistry
      • • Institute of Physical Chemistry
      Peping, Beijing, China
  • 2003
    • Shanghai Research Institute of Chemical Industry
      Shanghai, Shanghai Shi, China
  • 2002
    • Beijing University of Technology
      Peping, Beijing, China