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71.
The ecological environment in Central Asia is vulnerable to pressure from human activity due to the physical geography and climatic fragility of this region. A set of indicators suitable for the future assessment of this pressure needs to be proposed. Thirty‐six topsoil samples (0–5 cm) were collected from roadsides in a suburban region of Bishkek, the capital of the Kyrgyz Republic in Central Asia, and a risk assessment of anthropogenically disturbed potentially toxic elements (PTEs) was systematically conducted with classic statistical methods. The results of detrended correspondence analysis and principal component analysis clearly showed that topsoil samples with high contents of PTEs (Pb, Zn and Cu) were strongly affected by traffic within a distance threshold of 200 m and that anthropogenic effects decreased significantly with increasing distance from the highway. The enrichment factor and anthropogenic contribution for Pb were the highest among the three PTEs, with average values of 2.0% and 47.4%, respectively, suggesting enrichment. However, the results of the human health risk assessment also indicated that noncarcinogenic risks did not occur for any of the anthropogenic PTEs. The reported method provides a new systematic pathway to reveal anthropogenic influences on the geochemical composition of soil. The conclusions of this work will be highly valuable as important guidelines for agriculture, and the results of the PTE contents will provide a scientific basis for soil collection in future studies. 相似文献
72.
The assay was aimed to study the effect of Hedyotis diffusa Willd superfines powder on immune function. Three groups of mice were gavaged with the drugs at doses of 1.75,1.25 and 0.75 g/kg once a day for 7 consecutive days, repectively. The mice of control group were administered with the same volume of saline.At the last time, mice were injected into the muscle with Newcastle disease vaccine,and get peripheral blood on days 7, 14 and 21 after the medicine administration. The enhancement of innate immune responses were evaluated by using CCK-8 method, hemagglutination inhibition test, macrophage phagocytic function test and organ coefficient method. The levels of lymphocytes proliferative capacity, serum antibody, peritoneal macrophage phagocytosis and the indexes of immune organs in mice were extremely significantly enhanced (P<0.01). Hedyotis diffusa dWilld superfines powder could extremely significantly regulate the immunity function of mice (P<0.01). 相似文献
73.
[目的]明确部分甜荞资源的营养保健成分含量,筛选出优质的甜荞资源。[方法]以产量较高的丰甜1号、平甜2号、纯甜1号、纯甜3号、纯甜4号、威甜1号、威甜2号和纯甜1408号为试验材料,测定了荞麦籽粒中总糖、还原糖、总淀粉、直链淀粉、支链淀粉、黄酮等含量,同时测定了籽粒的膨胀力和持水力。[结果]部分甜荞品种中可溶性蛋白、可溶性总糖、还原糖、总淀粉、支链淀粉、直链淀粉含量及持水力、膨胀力差异显著,而所有品种间黄酮含量的差异不显著。[结论]甜荞籽粒中淀粉含量较高,以支链淀粉为主。 相似文献
74.
茶文化作为中华优秀传统文化的重要组成部分,其蕴含的心理健康教育思想内容丰富且历史悠久。近年来高校大学生数量激增,学生心理健康问题层出不穷,在高职院校中尤为凸显,且高职林科类院校中艰苦专业多,当前心理健康教育方式方法出现瓶颈,效果固化。通过茶文化中积极健康的思想,结合大学生心理健康教育教学,创新教育途径,探索并找到较好的实践运用手段,提高大学生的心理健康素质,促进大学生综合水平提高,具有较好现实意义和价值。 相似文献
75.
运用现代组织设计的相关理论,对传统大学图书馆的组织结构进行深入剖析,分析了制约大学图书馆功能发挥的各种因素,提出了现代大学图书馆的组织结构设计方案。该方案能够兼顾图书馆教学、学科建设与科研以及图书馆的基本服务功能。 相似文献
76.
77.
句子的功能所实现的交际任务是传递信息。根据话语信息传递和语言交际功能理论原则,通过甄选科技英语相关例证作为分析语料,从英语的科技文体视角探析了疑问句在科技英语信息推进中的五大作用,同时指出了解这些相关作用的必要性。 相似文献
78.
The nontarget effects of fresh and used motor oil were studied in a soil test system involving such criteria as earthworm survival, response of soil dehydrogenase and urease, and nitrification. When earthworms were exposed to motor oil-contaminated soil for 4 weeks, the observed median lethal concentrations (LC50) were 40.33 and 3.88 g kg−1 soil for fresh and used oil, respectively. Only fresh motor oil application increased earthworms' body weight even at the higher dose of 19 g kg−1 soil. Gas chromatography/mass spectrometry revealed that used motor oil contained more of aromatic hydrocarbons and heavy metals than fresh oil. This disparity in the chemical composition might be the factor responsible for the significant toxicity of used motor oil towards earthworms. Activities of soil dehydrogenase and urease were significantly enhanced in presence of both the motor oils, while there was a significant inhibition in nitrification by the used motor oil even at a low concentration of 0.2 g kg−1 soil. This study clearly demonstrated that earthworm survival and nitrification could serve as suitable indices to assess motor oil pollution in soil. 相似文献
79.
枣树具有独特的开花结果特性,为获得枣花发育基因,以金丝4号枣不同发育时期的花蕾和同时期的叶片cDNA互为试验方和驱动方,利用抑制消减杂交技术分别构建了枣花和枣叶抑制消减杂交cDNA文库(SSH文库)。枣花和枣叶SSH文库重组率分别是92.05%和90.26%,插入片段长度均介于200~2 000 bp之间,主要集中于1 000 bp左右。分别从枣花和枣叶SSH文库中随机挑选1 000个阳性克隆进行DNA测序、组装拼接,结果显示枣花SSH文库中获得96条unigene,其中contigs 43个,singletons 53个,96条unigene预测得到73个ORF,经过同源比对分析获得有注释的序列20条,按功能分为7类;枣叶SSH文库中获得86条unigene,其中contigs 45个,singletons 41个,86条unigene预测得到70个ORF,经过同源比对分析获得有23条注释的序列,按功能分为6类。 相似文献
80.
依据价值分析理念,对大兴安岭生态功能区进行了区划分析,并构建了大兴安岭生态功能区建设的"G+X"管理模式。 相似文献