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Effects of butachlor on microbial enzyme activities in paddy soil

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Journal of Environmental Sciences 2002年第3期14卷 413-417页

作者： MinH YeYF DepartmentofBiologyscience CollegeofLifeScienceZhejiangUniversityHangzhou310029China.E－mail：minhang@*** DepartmentofBiologyscience CollegeofLifeScienceZhejiangUniversityHangzhou310029China.

This paper reports the influences of the herbicide butachlor( n butoxymethl chloro 2', 6' diethylacetnilide) on microbial respiration, nitrogen fixation and nitrification, and on the activities of dehydrogenase and hydrogen peroxidase in paddy soil. The results showed that after application of butachlor with concentrations of 5.5 μg/g dried soil, 11.0 μg/g dried soil and 22.0 μg/g dried soil, the application of butachlor enhanced the activity of dehydrogenase at increasing concentrations. The soil dehydrogenase showed the highest activity on the 16th day after application of 22.0 μg/g dried soil of butachlor. The hydrogen peroxidase could be stimulated by butachlor. The soil respiration was depressed within a period from several days to more than 20 days, depending on concentrations of butachlor applied. Both the nitrogen fixation and nitrification were stimulated in the beginning but reduced greatly afterwards in paddy soil.

关键词： herbicide butachlor microbial enzyme activity paddy rice soil

Characterization and phylogenetic analysis of a phenanthrene-degrading strain isolated from oil-contaminated soil

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Journal of Environmental Sciences 2004年第4期16卷 589-593页

作者： XIAYing MINHang LUZhen-mei YEYang-fang collegeoflifescience ZhejiangUniversityHangzhou310029China

Bacterium strain EVA17 was isolated from an oil-contaminated soil, and identified as Sphingomonas sp. based on analysis of 16S rDNA sequence,cellular fatty acid composition and physiological-chemical tests. The salicylate hydroxylase and catechol 2,3-dioxygenase(C23O) were detected in cell-free lysates, suggesting a pathway for phenanthrene catabolism via salicylate and catechol. Alignment showed that both of the C23O and GST genes of the strain EVA17 had high similarity with homologues of strains from genus Sphingomonas. The phylogenetic analysis based on 16S rDNA and C23O gene sequence indicated that EVA17 should be classified into genus Sphingomonas, although the two phylogenetic trees were slightly different from each other. The results of co-amplification and sequence determination indicated that GST gene should be located upstream of the C23O gene.

关键词： phenanthrene 16S rDNA glutathione S-transferase catechol 2,3-dioxygenase phylogenetic analysis

MI-QSAR models for prediction of corneal permeability of organic com-pounds

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Acta Pharmacologica Sinica 2006年第2期27卷 193-204页

作者： Cheng CHEN Jie YANG~2 State Key Laboratory of Pharmaceutical Biotechnology,College of Life Science,Nanjing University,Nanjing 210093,China StateKeyLaboratoryofPharmaceuticalBiotechnology CollegeofLifeScienceNanjingUniversityNanjing210093China

Aim:To derive a theoretical model for the prediction of corneal permeability ofmiscellaneous organic compounds in drug ***:A training set of 28structurally diverse compounds was used to build up the membrane-interactionquantitative structure-activity relationship(MI-QSAR)*** intramolecular solute descriptors were computed using molecular mechanics,molecular dynamics simulations and quantum *** QSAR models wereoptimized using multidimensional linear regression fitting and a stepwise method.A test set of 8 compounds was evaluated using the models as part of a ***:Significant MI-QSAR models(R=0.976,S-0.1301,F=70.957)ofcorneal permeability of organic compounds were *** permeabil-ity was found to depend upon the sum of net atomic charges of hydrogen atomsattached to the heteroatoms(N,O),the sum of the absolute values of the netatomic charges of oxygen and nitrogen atoms,the principal moment of inertia(X),the Connolly accessible area and the conformational flexibility of the solute-mem-brane ***:The MI-QSAR models indicated that the cornealpermeability of organic molecules was not only influenced by the organic solutesthemselves,but also related to the properties of the solute-membrane complex,that is,the interactions of the molecule with the phospholipid-rich regions ofcellular membranes.

关键词： cornea permeability quantitative structureactivity relationship theoretical models

A Global Minimization Algorithm for Empirical Contact Potential Functions

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Chemical Research in Chinese Universities 2004年第5期20卷 572-574页

作者： WANGYu-hong LIWei collegeoflifescience JilinUniversityChangchun130023P.R.China

Global minimization algorithm is indispensable to solving the protein folding problem based upon thermodynamic hypothesis. Here we propose a pseudo potential function, contact difference(CD), for simulating empirical contact potential functions and testing global minimization algorithm. The present paper covers conformational sampling and global minimization algorithm called BML03, based upon Monte Carlo and simulated annealing, which is able to locate CD′s global minimum and refold extended protein structures into ones with root mean square distance(RMSD) as small as 0.03 nm from the native structures. For empirical contact potential functions, these results demonstrate that their global minimization problems may be solvable.

关键词： Global minimization Contact potential function Simulated annealing Monte Carlo simulation

Relationship between ATPase activity and conjugated polyamines in mito-chondrial membrane from wheat seedling roots under osmotic stress

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Journal of Environmental Sciences 2004年第5期16卷 712-716页

作者： LIUHuai-pan LIUJun ZHANGYan-yan LIUYou-liang KeyLaboratoryofCropGrowthRegulation MinistryofAgricultureCollegeofLifeScienceNanjingAgricultureUniversityNanjing210095China

The effects of osmotic stress on the ATPase activity, the contents of —SH group and conjugated polyamines in mitochondrial membrane from wheat seedling [Triticum aestivum L. cv. Yumai No.18(drought-tolerant) and cv. Yumai No.9(drought-sensitive)] roots were investigated. The results showed that ATPase activity and —SH group content decreased with polyethylene glycol(PEG) 6000(-0.55 MPa) treatment for 7 d, in concert with the decrease of the ratio of noncovalently conjugated spermidine(NCC-Spd)/noncovalently conjugated putrescine(NCC-Put) and increase of the covalently conjugated putrescine(CC-Put). Osmotic stress injury to Yangmai No.9 seedlings was alleviated greatly with 1 mmol/L exogenous spermidine(Spd), in concert with marked increases of the ratio of NCC-Spd/NCC-Put, —SH group contents and ATPase activity in mitochondrial membrane. Under osmotic stress, the concomitant treatment of Yumai No.18 seedlings with methylglyoxyl bis(guanylhydrazone) (MGBG), an inhibitor of S-adenosyl methionine decarboxylase(SAMDC), and phenanthrolin (o-Phen), an inhibitor of transglutaminase(TGase), caused a significant decrease of the ratio of NCC-Spd / NCC-Put, CC-Put contents, respectively, in concert with the marked decreases of ATPase activity, —SH group content and its tolerance to osmotic stress. All the results above suggested that osmotic stress tolerance of wheat seedlings was associated with the ATPase activity, the contents of —SH group, NCC-Spd and CC-Put in mitochondrial membrane.

关键词： ATPase conjugated polyamines mitochondria osmotic stress wheat(Triticum aestivum L.)

New ommatids from the Late Jurassic of western Liaoning, China （Coleoptera： Archostemata）

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Insect Science 2005年第3期12卷 207-216页

作者： JING-JINGTAN DONGREN MINGLIU collegeoflifescience CapitalNormalUniversityBeijingChina

A new genus Amblomma gen. nov. of fossil beetles is erected and can be assignedto the family Ommatidae because its two procoxal cavities are contiguous and the articulations of the abdominal ventrites are abutting. The new genus is similar to Zygadenia Handlirsch, 1906 (=Notocupes Ponomarenko, 1964), Tetraphalerus Waterhouse, 1901,Rhobdocupes Ponomarenko, 1966 and Sinocupes Lin, 1976, but can be distinguished from other genera according to the following characters: the second segment of antennae is shorterthan the third one in length; the posterior tarsi with the basal segment is obviously shorter than the three following taken together in length; the antennae reach the posterior ridge of prothroax in length, and the sides of the prothroax with serrulate margin. Four new species of the new genus are described and figured: Amblomma psilata gen. et sp. nov., Amblomma rudis gen. et sp. nov., Amblomma epicharis gen. et sp. nov., and Amblomma stabilis gen. etsp. nov. A key to species within this new genus is provided. All the specimens are collected from the Late Jurassic Yixian Formation of western Liaoning and are now housed in the College of Life Science, Capital Normal University, Beijing, China.

关键词：晚侏罗纪辽宁西部地区鞘翅目原鞘亚目新种化石形态特征鉴定

Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillsid

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Journal of Zhejiang University Science 2004年第10期5卷 1191-1198页

作者：陈欣杨一松唐建军 DepartmentofBioscience CollegeofLifeScienceZhejiangUniversityHangzhou310029China

Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m^2 and separated by 2m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability.

关键词：植物多样性生态系统气候土壤侵蚀生物多样性保护生态平衡

Dynamic expression pattern of zebrafish bfabp (fabp7) during early embryogenesis

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Chinese Science Bulletin 2004年第4期49卷 419-420页

作者： ZHONGHanbing ZHUZuoyan FANQichang collegeoflifescience PekingUniversityBeijing100871China

The expression of bfabp is correlated with the development of nervous system[1,2].

关键词：胚胎发生染色体组结构斑纹鱼基因表达

Receptive field plasticity of neurons in rat auditory cortex

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Chinese Science Bulletin 2004年第13期49卷 1364-1369页

作者： YANGWenwei GAOLixia SUNXinde ResearchCenterforBrainScience CollegeofLifeScienceEastChinaNormalUniversityShanghai200062China

Using conventional electrophysiological technique, we investigated the plasticity of the frequency receptive fields (RF) of auditory cortex (AC) neurons in rats. In the AC, when the frequency difference between conditioning stimulus frequency (CSF) and the best frequency (BF) was in the range of 1--4 kHz, the frequency RF of AC neurons shifted. The smaller the differences between CSF and BF, the higher the probability of the RF shift and the greater the degree of the RF shift. To some extent, the plasticity of RF was dependent on the duration of the session of conditioning stimulus (CS). When the frequency difference between CSF and BF was bigger, the duration of the CS session needed to induce the plasticity was longer. The recovery time course of the frequency RF showed opposite changes after CS *** RF shift could be induced by the frequency that was either higher or lower than the control BF, demonstrating no clear directional preference. The frequency RF of some neurons showed bidirectional shift, and the RF of other neurons showed single directional shift. The results suggest that the frequency RF plasticity of AC neurons could be considered asan ideal model for studying plasticity mechanism. The present study also provides important evidence for further study of learning and memory in auditory system.

关键词：制约刺激频率可塑性神经细胞听觉皮层感受域老鼠