基于斑马鱼模型的补益类中药抗血管生成活性筛选

目的利用荧光转基因斑马鱼模型筛选补益药,比较中药水提取物对斑马鱼胚胎血管生成的作用差异,为补益类中药抗肿瘤作用机制的探索以及抗肿瘤新药的研发提供方向。方法以TG(flk1:m Cherry)系荧光转基因斑马鱼作为筛选模型,将24味补益类中药,按照20、50、100、150、300μg·m L^-1的药物浓度分别作用于斑马鱼胚胎,观察其对斑马幼鱼节间血管生成的影响,并进行定量分析。结果何首乌具有促进血管生成作用,另外11种中药百合、党参、杜仲、甘草、高良姜、黄芪、肉桂、桑寄生、石斛、天冬、五味子对斑马鱼幼鱼的血管生成起到抑制作用,且具有一定的量效关系。结论此次研究可以为抗肿瘤中药的作用机制研究、临床应用以及抗肿瘤药物先导化合物的发现提供新的思路。

Distribution of Soil Enzyme Activities and Microbial Biomass Along a Latitudinal Gradient in Farmlands of Songliao Plain,Northeast China

Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in farmlands of Songliao Plain, Northeast China to assess the impact of climatic changes along the latitudinal transect on nutrient cycling in agroecosystems. Top soils (0-20 cm depth) were sampled in fields at 7 locations from north (Hailun) to south (Dashiqiao) in the end of October 2005 after maize harvest. The contents of total C, N, and P, C/N, available N, and available P increased with the latitude. The activities of invertase and acid phosphatase, microbial biomass (MB) C and N, and MBC/MBN were significantly correlated with latitude (P < 0.05, r2 = 0.198, 0.635, 0.558, 0.211 and 0.317, respectively), that is, increasing with the latitude. Significant positive correlations (P < 0.05) were observed between invertase activity and the total N and available P, and between acid phosphatase activity and the total C, C/N, available N, total P and available P. The urease, acid phosphatase, and dehydrogenase activities were significantly correlated with the soil pH and electrical conductivity (EC) (P < 0.05). MBC and MBN were positively correlated with the total C, C/N, and available P (P < 0.05). The MBC/MBN ratio was positively correlated with the total C, total N, C/N, and available N (P < 0.05). The spatial distribution of soil enzyme activities and microbial biomass resulted from the changes in soil properties such as soil organic matter, soil pH, and EC, partially owing to variations in temperature and rainfall along the latitudinal gradient.

Effect of heavy metals on soil nematode communities in the vicinity of a metallurgical factory

The influence of Cu and Zn on soil nematode communities was examined along a pollution gradient with increasing distance from a metallurgical factory. Total and available heavy metal contents were used to study the effects of heavy metals on nematode abundance, trophic groups and ecological indices. The results demonstrated significant correlations between the number of total nematodes, bacterivores, plant-parasites and the total and available heavy metals. Bacterivores and plant-parasites were the dominant trophic groups. Significant differences in different sampling sites were found only in the number of bacterivores（P〈0.01）. The Shannon-Weaver diversity index（W）, trophic diversity index（TD）, evenness index（J＇） and dominance index（λ） were found to be sensitive to soil pH and C/N ratios. Significant correlations were found between the total nematodes （TNEM）, some genera （A crobeloides, Aphelenchoides, Cephalobus, Ditylenchus, Mesorhabditis, Tetylenchus and Tylenchus） and distance from the factory.

Nematode Faunal Response to Grassland Degradation in Horqin Sandy Land

The responses of soil nematode communities to grassland degradation were studied under undegraded grassland (UG), degraded grassland (DG),and improved grassland (IG),in Horqin Sandy Land,Inner Mongolia,Northeast China.Soil samples were collected at depths of 0-10,10-20,and 20-30 cm.Total organic carbon (TOC) and total nitrogen (TN) exhibited positive effects on the total number of nematodes and trophic groups.Significant treatment effects were found in the total number of nematodes,plant parasites,and omnivores-predators.Measures taken in the improved grassland could improve the number of omnivore-predators,especially in the deeper soil layers.Nematode richness was lower in the DG treatment than in the IG and UG treatments.The food web structure index (SI) was significantly higher in the UG and IG treatments than in the DG treatment.A higher SI suggested a food web with more trophic linkages and relatively healthy ecosystems.

Nematode Diversity in Phaeozem Agroecosystems of Northeast China

The diversity and distribution patterns of soil nematode communities in phaeozem agroecosystems of Northeast China were assessed to evaluate nematode taxonomic diversity and functional diversity in relation to climatic condition and soil characteristics in human modified landscape.Along the latitudinal gradient,soil samples were collected from north(Hailun) to south(Gongzhuling) down to a depth of 100 cm with intervals of 0-20,20-40,40-60,60-80,and 80-100 cm.The nematode abundance and taxonomic diversity(generic richness) were lower at Hailun than at other sites,and higher values of evenness were observed at Hailun and Harbin than at Dehui and Gongzhuling.Nematode faunal analysis revealed that soil food web at Hailun was successionally more mature or structured,and the environment little disturbed,while at Harbin and Gongzhuling,the soil food web was degraded with stressed environment.The environmental variables relevant in explaining the patterns of nematode distribution and diversity in phaeozem agroecosystems,using canonical correspondence analysis(CCA),were the mean annual temperature,total nitrogen,electrical conductivity,mean annual precipitation,and other soil properties.Among these variables,the mean annual temperature was a relatively important factor,which could explain 29.05% of the variations in nematode composition.

基于网络药理学及分子对接的川乌、草乌配伍治疗类风湿性关节炎的机制研究

目的基于网络药理学及分子对接技术研究川乌、草乌相须配伍治疗类风湿性关节炎潜在的有效成分及其作用机制,为川乌、草乌治疗类风湿性关节炎提供参考。方法通过中药系统药理学数据库及分析平台(TCMSP)中以口服生物利用度(oral bioavailability,OB)、类药性(Drug-likeness,DL)参数筛选川乌、草乌的成分,采用PharmMapper数据库寻找川乌、草乌的作用靶点,与疾病数据库GeneCards及OMIM数据库中类风湿性关节炎的靶点取交集。在String平台进行蛋白质-蛋白质相互作用(PPI)分析,Metascape平台进行基因本体(Gene Ontology,GO)分析及京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)通路富集分析。通过Cytoscape软件构建“药物-成分-类风湿性关节炎靶点-通路”网络。利用SYBYL软件进行分子对接。结果筛选出10个潜在活性成分(次乌头碱、滇乌头碱、草乌甲素等),23个对应治疗靶点(TGFB2、IL2、MMP3、MMP2等),涉及类风湿性关节炎、白细胞介素-17、MAPK、JAK-STAT等通路及炎症反应、防御反应等生物过程。结论川乌、草乌通过多成分、多靶点、多通路协同治疗类风湿性关节炎,且有多个成分表现出很强的活性,为后续研究提供一定的参考。

Response of Nematodes in a Hapli-Udic Argosol to Urea Amended with Urease and Nitrification Inhibitors

Effects of urea amended with urease and nitrification inhibitors on soil nematode communities were studied in a Hapli-Udic Argosol (Cambisoi, FAO) in Liaoning Province of Northeast China. A completely random design with four treatments, i.e., conventional urea (CU), slow-release urea amended with a liquid urease inhibitor (SRU1), SRU1 + nitrification inhibitor dicyandiamide (SRU2), and SRU1 + nitrification inhibitor 3,5-dimethylpyrazole (SRU3) and four replicates were applied. Thirty-nine genera of nematodes were identified, with Cephalobus and Aphelenchus being dominant; and in all treatments, the dominant trophic group was bacterivores. In addition, during the growth period of spring wheat (Triticum aestivum L.), soil urease activity was lower in SRUs than in CU. The numbers of total nematodes and bacterivores at wheat heading and ripening stages, and omnivores-predators at ripening stage were higher in SUR3 than in CU, SRU1 and SRU2 (P < 0.05).

Partial organic substitution weakens the negative effect of chemical fertilizer on soil micro-food webs

Soil biotic communities play vital roles in enhancing soil nutrient cycling and soil fertility.Long-term excessive nitrogen(N)application is disadvantageous to the stability of soil food webs and affects arable soil health and sustainable utilization.Proper organic substitution is essential to improve soil health and alleviate the disadvantages of excessive chemical fertilization.However,the biological effects of various organic amendments on soil micro-food webs are poorly understood.In order to explore the effects of various organic amendments including stover,biochar and manure on soil micro-food webs(microbial and nematode communities),a field plot experiment with maize having five treatments viz.,100%urea(100%N),70%urea(70%N),70%urea plus stover(Stover),70%urea plus cattle manure(Manure)and 70%urea plus biochar(Biochar)was conducted.Manure treatment increased the carbon(C)to N use efficiency of soil microbes,which contributed to the retention of soil C,while Biochar treatment elevated soil organic C(SOC)and soil p H.Additionally,Biochar treatment mitigated the negative effects of soil acidification on the soil micro-food web and reduced the abundance of plant parasites.Overall,the biological effect of organic amendments was distinguished from chemical fertilization(100%N and 70%N)through principal co-ordinates analysis.Negative relationships among soil properties,microbial and nematode biomass in the 100%N treatment were diminished in treatments where chemical fertilizer was reduced.The bottom-up effects on soil food webs were observed in organic substitution treatments.In conclusion,organic amendments improved soil fertility by regulating soil microbial and nematode communities in the cropland ecosystem,alleviated the negative effects of chemical fertilizer on the micro-food webs and controlled the trophic cascades among soil biota.

新电力体制改革对电网企业投资运营及管理的影响

随着中国近年来的不断崛起,中国发展呈现出一片红的局势,为保障我国经济的正常发展,电力消耗不断加强,我国电网企业可以说是起到了非常重要的作用。与此同时,为了跟上时代发展需要,更好满足社会发展需求,形成一套健全的电力体制对电力发展具有深远的意义。在这深远意义背后我们能解析出很多问题,主要体现在新电力体制会让电网各方面的触及利益的矛盾日益明显。与此同时电网诸多方面的问题会不断显现出来。福祸相依,机遇与挑战共存,文章将讨论新电力体制改革带来的影响,并提出了相应处理的措施。

基于输配电价改革背景下电网企业资产管理研究

随着我国实行了输配电价改革,一方面提高了我国电力市场的整个竞争环境,也让电力市场更加的公平公正;另一方面,输配电价改革也改变了电网企业的经营模式,给电网企业带来的巨大的挑战。面对新的环境,电网企业需要不断的加强自身管理,其中资产管理作为重要的管理方面,直接关乎着企业的收入和利润,所以本文研究基于输配电价改革背景下电网企业资产管理。首先对输配电价改革这一背景进行分析,分析其改革的相关内容和改革的意义。输配电价改革能够营造更好的市场氛围,然而电网企业面对新的环境,一时难以适应,于是文章提出了新背景下电网企业资产管理存在的问题。最后通过分析电网企业资产管理,得出一些管理策略,该策略能够帮助到电网企业更快的适应新的环境。

土壤健康的生物学表征与调控

如何有效判定土壤健康状态是实现农业绿色发展的基本问题。在现有的土壤健康评价体系中,很少考虑土壤生物在维持土壤健康方面的作用。基于此,本文论述了土壤健康的内涵,从土壤生物健康的角度,总结了土壤健康的生物学表征指标,阐述了土壤微生物、土壤酶活性、土壤微食物网及蚯蚓对土壤健康的指示作用。基于上述生物指标,从作物和土壤管理等方面探讨了不同农田管理措施对土壤健康状况的调控途径,并对土壤生物健康的未来发展趋势进行了展望。本文旨在增强科学家和决策者对维护土壤生物健康的认识,充分发挥土壤生物在生态系统服务中的重要作用。

Distribution of Soil Organic Carbon Fractions Along the Altitudinal Gradient in Changbai Mountain,China

Understanding the responses of soil organic carbon(SOC) fractions to altitudinal gradient variation is important for understanding changes in the carbon balance of forest ecosystems.In our study the SOC and its fractions of readily oxidizable carbon(ROC),water-soluble carbon(WSC) and microbial biomass carbon(MBC) in the soil organic and mineral horizons were investigated for four typical forest types,including mixed coniferous broad-leaved forest(MCB),dark coniferous spruce-fir forest(DCSF),dark coniferous spruce forest(DCS),and Ermans birch forest(EB),along an altitudinal gradient in the Changbai Mountain Nature Reserve in Northeast China.The results showed that there was no obvious altitudinal pattern in the SOC.Similar variation trends of SOC with altitude were observed between the organic and mineral horizons.Significant differences in the contents of SOC,WSC,MBC and ROC were found among the four forest types and between horizons.The contents of ROC in the mineral horizon,WSC in the organic horizon and MBC in both horizons in the MCB and EB forests were significantly greater than those in either DCSF or DCS forest.The proportion of soil WSC to SOC was the lowest among the three main fractions.The contents of WSC,MBC and ROC were significantly correlated(P < 0.05) with SOC content.It can be concluded that vegetation types and climate were crucial factors in regulating the distribution of soil organic carbon fractions in Changbai Mountain.

Soil Nematode Response to Biochar Addition in a Chinese Wheat Field

While studies have focused on the use of biochar as soil amendment, little attention has been paid to its effect on soil fauna. The biochar was produced from slow pyrolysis of wheat straw in the present study. Four treatments, no addition (CK) and three rates of biochar addition at 2 400 (B1), 12 000 (B5) and 48 000 kg ha-1 (B20), were investigated to assess the effect of biochar addition to soil on nematode abundance and diversity in a microcosm trial in China. The B5 and B20 application significantly increased the total organic carbon and the C/N ratio. No significant difference in total nematode abundance was found among the treatments. The biochar addition to the soil significantly increased the abundance of fungivores, and decreased that of plant parasites. The diversity of soil nematodes was significantly increased by B1 compared to CK. Nematode trophic groups were more effectively indicative to biochar addition than total abundance.