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971.
972.
本文简要分析不确定性因素对经济评价指标的影响,和不确定性分析的几种方法,确定项目在经济上的可靠性。 相似文献
973.
974.
Inhibitory activity of homoisoflavonoids from Caesalpinia sappan against Beauveria bassiana 总被引:2,自引:0,他引:2
Niranjan Reddy VL Ravikanth V Jansi Lakshmi VV Suryanarayan Murty U Venkateswarlu Y 《Fitoterapia》2003,74(6):600-602
Four homoisoflavonoids, 4-O-methylsappanol (1), protosappanin A (2), brazilin (3) and caeasalpin J (4), isolated from Caesalpinia sappan, were tested for inhibitory activity against Beauveria bassiana. Compound 1 showed activity against this fungus. 相似文献
975.
A dose-dependent and significant (P<0.01) antiproliferative effect of Goldfussia psilostachys ethanolic extract was observed on K562 cells. The IC(50) is ca. 0.5 microg/ml. The extract markedly increases the proportion of cell in G2/M phases and decreases the population of cells in G0/G1 phases. Moreover, the antimitotic effect is correlated with polymerization of microtubule assembly. These results indicate that G. psilostachys ethanolic extract inhibits the proliferation of K562 cells and disrupts the normal dynamic of microtubules during mitosis. 相似文献
976.
Dong Qin Lijuan Zhao Yu Gary Gao Fangxiao Li Shulei Li Junwei Huo Shuang Lou Peng Liu 《林业研究》2017,28(5):903-908
To elucidate mechanisms regulating ascorbic acid (AsA) biosynthesis and accumulation in the fruit and leaves of black currants, AsA and the activities of key enzymes in the ascorbate–glutathione (AsA–GSH) cycle were measured from fruit set to fruit ripening during fruit thinning treatments of three common commercial black currant cultivars that differed in their AsA levels: ‘Risager’ (low), ‘Brodtrop’ (medium) and ‘Adelinia’ (high). Treatments were 50% fruit reduction (50% of total fruit set) by hand, control was no thinning. Fruit thinning treatment significantly increased AsA content in fruit of all three cultivars from weeks 2 to 8, significantly decreased AsA content in leaves from weeks 3 to 8. Dehydroascorbate reductase and monodehydroascorbate reductase activities in fruit and leaves had a similar pattern, increasing during week 2, rose until they peaked in week 4. Ascorbate peroxidase activity in fruit in the thinning treatment was slightly lower than in the control. Fruit thinning was shown to be a good model to test AsA biosynthesis regulation and accumulation in black currants. The results from our study provided strong evidence that AsA–GSH cycle involved in AsA synthesis and accumulation in fruit. 相似文献
977.
Shu Diao Yanbo Wang Changjun Ding Yingying Chang Lixiong Liang Yanan Gao Bingyu Zhang Xiaohua Su 《林业研究》2017,28(4):653-660
DNA methylation, an epigenetic mechanism used by cells to control gene expression, has an important biological role in plant development and environmental fitness. Since plant DNA methylation is closely related to environmental conditions, variation during the day is expected. Here, in genetically identical plants of Populus nigra clone N46, DNA methylation changes in leaves over a 24 h period were detected using the methylation-sensitive amplification polymorphism method. The results showed different DNA methylation patterns in mature poplar leaves: not only in individuals at the same time, but also in samples at each of the six time during the day. In addition, night samples had a higher percentage of methylation than in morning samples. However, no statistically significant differences were found among the samples gathered at different times. Similar results were obtained for three other P. nigra clones with different genetic backgrounds. Real time qPCR showed that the DNA methyltransferase genes Pt-MET1 and Pt-SOM1 involved in CG DNA methylation in poplar were stable over a 24 h period in leaves of P. nigra N46 compared with circadian-controlled genes. That could be part of the reason that methylation of CCGG sites is stable in those leaves. That DNA methylation differed even in genetically identical plants indicates the specificity of DNA methylation changes in their genomes. No statistically significant differences in methylation changes were found between day and night, suggesting that DNA methylation is more stable than expected and is unlikely to be involved in circadian regulation in plants. 相似文献
978.
Yu Wu Ji Zhang Xiao-Juan Jin Jian-Min Gao Qiang Zhao 《Wood Science and Technology》2014,48(4):713-725
Nitrogen-enriched activated carbons were prepared from waste medium density fiberboard waste by using NaOH, K2CO3 and KOH. The content of nitrogen in the activated carbon was 0.92, 0.74 and 1.33 % by analysis. The influence of contact time, pH, Cr(VI) initial concentration and the amount of activated carbon on the Cr(VI) adsorption capacity were investigated. The maximum adsorption capacity of Cr(VI) could reach 89.21 mg/g at pH 2 and a contact time of 9 h. The kinetics adsorption followed nicely the pseudo-second-order rate expression. In adsorption isotherm, the Langmuir model fitted better than the Freundlich model. Pure Poplar activated carbon was also prepared as the adsorbent for Cr(VI) removal as control sample. This study indicated that the nitrogen-enriched activated carbon prepared from waste medium density fiberboard can be used effectively for the removal of Cr(VI) compound from aqueous solutions. 相似文献
979.
The ethyl acetate, acetone and methanol extracts of Wrightia tinctoria bark showed antinociceptive activity on acetic acid-induced writhing test in mice, their effects being comparable to that of acetylsalicylic acid. 相似文献
980.
Biological activity of Glechoma hederacea 总被引:2,自引:0,他引:2
The n-hexane, dichloromethane and methanol extracts of the aerial parts of Glechoma hederacea have been screened for antibacterial and free radical scavenging activity. General toxicity (brine shrimp lethality assay) of these extracts has also been assessed. 相似文献