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A comparative molecular field analysis of cytotoxic beta-carboline analogs

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Acta Pharmacologica Sinica 2004年第7期25卷 113-119页

作者： Xue-rui HOU, Qi CHEN, Ri-hui CAO, Wen-lie PENG, An-long XU1 Department of Biochemistry and Center for Biopharmaceutical Research, college of life sciences, sun yat-sen university, guangzhou 510275, china Department of Biochemistry and Center for Biopharmaceutical Research College of Life Sciences Sun Yatsen University Guangzhou 510275

AIM: To derive a model that could be used in drug design. METHODS: Beta-carbolines are reported to have antitumor activities on cultured cancer cell lines. A comparative molecular field analysis (CoMFA) was undertaken to elucidate the correlation of cytotoxities and structural parameters of 16 beta-carboline analogs (1-16). The compound 12 was finally used as a template for the other compounds in the dataset because of its highest biological activity. RESULTS: The CoMFA applied to the final alignment resulted in a qcv of 0.656 and it showed that the 2 steric fields contributed 43.3 % of the model information while the electrostatic fields represented the other 56.7 %. CONCLUSION: Three designed compounds, which were predicted to have high, moderate and low activities respectively, were synthesized. The IC50 values of these compounds indicated the significance of the analysis in this study. The model derived from the current study could be further used in design for more active compounds.

关键词： beta-carbolines quantitative structure-activity relationship alkaloids

Bacterial Phosphoproteomic Analysis Reveals the Correlation Between Protein Phosphorylation and Bacterial Pathogenicity

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Genomics,Proteomics & Bioinformatics 2011年第Z2期 119-127页

作者： Ruiguang Ge and Weiran Shan Laboratory of Integrative Biosciences, college of life sciences, sun yat-sen university, guangzhou 510275, china

Increasing evidence shows that protein phosphorylation on serine, threonine and tyrosine residues is a major regulatory post-translational modification in the bacteria. This review focuses on the implications of bacterial phosphoproteome in bacterial pathogenicity and highlights recent development of methods in phosphoproteomics and the connectivity of the phosphorylation networks. Recent technical developments in the high accuracy mass spectrometry have dramatically transformed proteomics and made it possible the characterization of a few exhaus- tive site-specific bacterial phosphoproteomes. The high abundance of tyrosine phosphorylations in a few bacterial phosphoproteomes suggests their roles in the pathogenicity, especially in the case of pathogen-host interactions; the high abundance of multi-phosphorylation sites in bacterial phosphoprotein is a compensation of the relatively small phosphorylation size and an indicator of the delicate regulation of protein functions.

关键词： protein phosphorylation bacterium pathogenicity phosphoproteomics

水稻内生放线菌类群及其对宿主病原菌的抗性研究

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微生物学报 2004年第5期44卷 641-646页

作者：田新莉曹理想杨国武黄炳超周世宁陈明肖汉翔广州中山大学生命科学学院生物防治国家重点实验室广州510275 广东省农业科学院植物保护研究所广州510275

采用常规方法对广东省番禺和五山两地种植的水稻内生放线菌进行分离、鉴定和分析 ,结果表明水稻内生放线菌多属于链霉菌属 (Streptomyces) ,其中灰褐类群链霉菌 (S .griseofuscus)的分离频率最高为 36 1%～ 6 9% ,是水稻植株中的优势... 详细信息

采用常规方法对广东省番禺和五山两地种植的水稻内生放线菌进行分离、鉴定和分析 ,结果表明水稻内生放线菌多属于链霉菌属 (Streptomyces) ,其中灰褐类群链霉菌 (S .griseofuscus)的分离频率最高为 36 1%～ 6 9% ,是水稻植株中的优势内生放线菌类群。研究了内生放线菌在水稻植株各器官中的分布 ,结果表明根中内生放线菌的多样性高于茎叶。番禺地区种植的水稻中分离出的内生放线菌种类较多。从感病品种及生长不良水稻植株中分离出的内生放线菌种类比较丰富。通过回接分离试验及利用扫描电镜观察内生菌在植物体内分布发现 ,水稻优势内生放线菌回接无菌组培苗后 ,不仅能够定殖在水稻植株的根表和根内部 ,而且存在于茎杆和叶片中。通过平板颉抗及代谢物的活性测定试验 ,发现所分离的内生放线菌 5 0 %对水稻某些病原菌有颉抗活性 ,其中灰褐类群链霉菌的比例达到 5 5 4 % ,成为所分离的水稻内生放线菌类群中具有颉抗活性的最大群体。

关键词：水稻内生放线菌体内定殖颉抗活性

RNomics:The New Frontier in the post-genomic era

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Science china(life sciences) 2009年第3期52卷 193-194页

作者： Liang-Hu Qu college of life sciences,sun Yan-sen university,guangzhou 510275,china college of life sciences Sun Yan-Sen University Guangzhou China

It has been shown that whenever there is breakthrough in DNA structure there follows a bloom period of RNA research.

关键词： RNomics RNA

Spontaneous chiral-symmetry breaking of lattice QCD with massless dynamical quarks

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Science china(Physics,Mechanics & Astronomy) 2007年第1期50卷 6-14页

作者： LUO XiangQian Department of Physics,School of Physics and Engineering,sun yat-sen university,guangzhou 510275,china Department of Physics School of Physics and Engineering Sun Yat-Sen University Guangzhou China

One of the most challenging issues in QCD is the investigation of spontaneous chiral-symmetry breaking, which is characterized by the non-vanishing chiral condensate when the bare fermion mass is zero. In standard methods of the lattice gauge theory, one has to perform expensive simulations at multiple bare quark masses, and employ some modeled functions to extrapolate the data to the chiral limit. This paper applies the probability distribution function method to computing the chiral condensate in lattice QCD with massless dynamical quarks, without any ambiguous mass extrapolation. The results for staggered quarks indicate that this might be a promising and efficient method for investigating the spontaneous chiral-symmetry breaking in lattice QCD, which deserves further investigation.

关键词： lattice QCD spontaneous chiral-symmetry breaking dynamical quarks

Chemical weathering and chemical runoffs in the seashore granite hills in South china

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Science china Earth sciences 2010年第8期53卷 1195-1204页

作者： GAO QuanZhou & TAO Zhen School of Geography and Planning, sun yat-sen university, guangzhou 510275, china School of Geography and Planning Sun Yat-sen University Guangzhou China

Surface runoffs and the contents of major ions and dissolved silicon were surveyed and analyzed based on weekly sampling for one year in a granite watershed of Zhuhai City, Guangdong Province. The results demonstrated that the slope runoff played an essential role in feeding the rivulet during precipitation, whereas the groundwater was more important for the rivulet in the non-raining stages. Dissolved silicon, Na+, HCO3-, and Clions constituted the major chemical components of the rivulet water. Atmospheric CO2 and H2SO4 sourced from the oxidation of pyrite were the main erosive mediums in the natural chemical weathering. Natural chemical weathering, the wet and dry deposition of sea-salt, and acids precipitation contributed approximately equal shares of anions to the rivulet water. The ratio of NO3- to SO42- was more than 1.0 in the runoff of the studied seashore watershed, whereas it is less than 1.0 in the Xijiang River that is adjacent to the study area. This implied that the chemical composition of runoff is controlled mainly by the differences in atmospheric acid precipitation caused by human activities and lithology within the catchments under the same bio-climate zone. The CO2 flux consumed by the rock chemical weathering processes within the seashore granite watershed in South china was (0.35-1.37)×105 mol km-2 a-1.

关键词： chemical weathering granite ion sea-salt acid deposition CO2

Studies on rickettsia-like organism (RLO) disease of tropical marine pearl oyster-Epidemiological investigation of RLO disease in juvenile populations of maricultured Pinctada maxima

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Acta Oceanologica Sinica 2003年第3期22卷 421-435页

作者： Xinzhong Wu , Dengfeng Li, Jinpei Pan, Jingbo Jiang college of Animal sciences,Zhejiang university,Hangzhou 310029,china. Email: wuxz@zju.edu.cnSouth china Sea Institute of Oceanology, Chinese Academy of sciences,guangzhou 510301,chinaSchool of life sciences,sun yat-sen university,guangzhou 510275,china college of Animal sciences Zhejiang University Hangzhou 310029 China South china Sea Inst. of Oceanology Chinese Academy of Sciences Guangzhou 510301 China School of life sciences SUN YAT-SEN University Guangzhou 510275 China

The death which occurred in juvenile population was a severe problem in the course ofPinctada maxima artificial culture. With the methods of field investigation, histological study and statistic analyses, the epidemiological study was carried out on the disease and death in juvenile populations of Pinctada maxima in the Xinying Pearl Oyster Mariculture Farm of Lingao County (for the A, B and C batches of cultured juveniles hanged in the sea) and the Xincun Pearl Oyster Mariculture Farm of Lingshui County (for the D batch of cultured juvenile hanged in the pond), Hainan Province from November 1993 to April *** results show that the deaths which occurred in juvenile populations of Pinctada maxima presented an outbreak pattern. The peak of mortality rates, in general, occurred in 4-to 6-month old pearl oyster juveniles, and the mortality rates gradully declined with the extention of pearl oyster age after cul-turing 8 months. The correlation between the mortality rates of juvenile populations and mean body lengths of juvenile populations show that the mortality rate become higher under 4 cm of mean body lengths of juvenile population and become obvious declined over 5 cm of mean body lengths. The peak of mortality rate occurred in 1-3 cm of mean body lengths. The results of histological observation showed that rickettsia-like organism inclusions were common, histological widespread infective agent among every batches (A, B, C and D) of cultured juvenile populations. The mean severity indices (SI) of rickettsia-like organism (RLO) infection were positively correlated with mortality rates of juvenile populations. After or within every peaks of RLO infection were all accompanied with the peaks of mortality rates of host populations and the mortality rates declined with decreased RLO infection. So the evidences of histological observation and epidemiology in this study indicated that rickettsia-like organism (RLO) may be as an important pathogenic organism of disease

关键词： Pinctada maxima rickettsia-like organism epidemiology juvenile population

IMPROVED DEM-CFD MODEL AND VALIDATION:A CONICAL-BASE SPOUTED BED SIMULATION STUDY

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Journal of Hydrodynamics 2010年第3期22卷 351-359页

作者： RONG Liang-wan ZHAN Jie-min Department of Applied Mechanics and Engineering Sun Yat-sen University Guangzhou 510275 China Department of Applied Mechanics and Engineering Sun Yat-sen University Guangzhou 510275 China Guangdong Province Key Laboratory of Coastal Ocean Engineering Sun Yat-sen University Guangzhou 510275China

An improved and efficient DEM-CFD approach is developed for spouted beds. A nonlinear Discrete Element Method （DEM）, with a concept of spring, dash-pot and friction slider, is used for tracing the movement of each individual particle. The gas flow is described by a set of reorganized governing equations. Two phases are coupled through contributions due to effects of porosity, viscosity and drag. All equations are solved with the commercial package Fluent with an implementation of User Defined Functions （UDF）. To validate the improved model, a two-dimensional conical-base spouted bed is chosen as a case study. An unstructured mesh system is adopted instead of regular grid system. The simulation also takes the Saffman force and Magnus effect into account. The calculation results show good agreement with the experimental observations which are taken from the literature.

关键词： Discrete Element Method (DEM) spouted bed Fluent User Defined Functions (UDF) unstructured mesh

Phylogenetic placement of Cynomorium in Rosales inferred from sequences of the inverted repeat region of the chloroplast genome

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Journal of Systematics and Evolution 2009年第4期47卷 297-304页

作者： ~(1,2)Zhi-Hong ZHANG ~3Chun-Qi LI ~2Jianhua LI~* 1(School of life sciences,sun yat-sen university,guangzhou 510275,china) 2(Arnold Arboretum of Harvard university,Cambridge,MA 02138,USA) 3(college of life sciences,Henan Agricultural university,Zhengzhou 450002,china) (School of life sciences Sun Yat-sen University Guangzhou 510275 China) (Arnold Arboretum of Harvard university Cambridge MA 02138 USA) (college of life sciences Henan Agricultural University Zhengzhou 450002 China)

Cynomorium is a herbaceous holoparasite that has been placed in Santalales,Saxifragales,Myrtales, or *** inverted repeat(IR)region of the chloroplast genome region is slow evolving and,unlike mitochondrial genes,the chloroplast genome experiences few horizontal gene transfers between the host and parasite. Thus,in the present study,we used sequences of the IR region to test the phylogenetic placements of Cynomorium. Phylogenetic analyses of the chloroplast IR sequences generated largely congruent ordinal relationships with those from previous studies of angiosperm phylogeny based on single or multiple *** was closely related to Caryophyllales and *** formed a clade where Peridiscus was sister to the remainder of the order, whereas Paeonia was sister to the woody clade of *** is not closely related to Santalales, Saxifragales,Myrtales,or Sapindales;instead,it is included in Rosales and sister to *** various placements of the holoparasite on the basis of different regions of the mitochondrial genome may indicate the heterogeneous nature of the genome in the ***,it is unlikely that the placement of Cynomorium in Rosales is the result of chloroplast gene transfer because Cynomorium does not parasitize on rosaceous plants and there is no chloroplast gene transfer between Cynomorium and Nitraria,a confirmed host of Cynomorium and a member of Sapindales.

关键词： Bayesian analyses chloroplast inverted repeat Cynomorium holoparasite maximum likelihood parsimony Rosales.