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41.
当今中国,炫耀性消费已成为一种时尚,了解进行炫耀性消费的人群,客观评价炫耀性消费的作用,正确认识炫耀性消费给我国带来的不良影响,才有利于合理消费理念的深入和发展. 相似文献
42.
43.
Land disposal of waste drilling fluid is an environmental concern because of the high salt content and the presence of potential toxic elements. A water-based drilling fluid was tested in a laboratory column study to determine the feasibility of leaching excessive salt without mobilizing chromium (Cr). The drilling fluid-affected two Alfisols with similar mineralogy, acidity, and texture were treated with gypsum (CaSO4 · 2H2O), calcium carbonate (CaCO3), or calcium phosphate (CaHPO4) (0 to 2% of weight). The electrical conductivity (EC) increased and the sodium adsorption ratio (SAR) decreased with increasing Ca-salt concentration. The pH did not vary significantly with the changes in the concentrations of gypsum and calcium phosphate. The pH of the mixtures increased in proportion to the concentration of added calcium carbonate. The hydraulic conductivity increased and the mobility of the soil particles decreased with increasing Ca-salt concentration. The Cr mobility decreased by gypsum and CaCO3 treatments but it increased by calcium phosphate treatment. The soil with a higher content of organic matter and cation exchange capacity (CEC) showed a higher hydraulic conductivity and lower Cr mobility than the other soils at the same levels of the treatment. The results of this study suggest that the amendment of drilling fluid-affected soils with CaCO3 and gypsum can enhance the leaching of excessive salt and reduce the Cr mobility. Among loamy soil, those with a higher CEC and organic matter content are more suitable for land disposal of drilling fluid. 相似文献
44.
MicroRNA(miRNA) is a class of important regulating non-coding small molecular RNA. The gma-MIR166 gene family consists of 21 members and their expression patterns diversify widely. It is important to analyze the evolution of gma-MIR166 gene family in order to understand the evolutionary mechanisms of miRNAs in soybean. In this study, we implemented soybean wide genome block analysis, the molecular phylogeny of gma-MIR166 and block analysis of gma-MIR166 family. The results showed that both chromosome big segmental duplications and tandem duplications were main reasons contributed to the expanding of gmaMIR166 gene family. These findings suggested that gma-MIR166 gene family might originate from one or two ancient miRNA genes. The results of research provided a support for evolutionary study of miRNAs in soybean and related species in Fabaceae. 相似文献
45.
应用PCR方法通过毛发进行哺乳动物性别鉴定 总被引:13,自引:2,他引:13
以哺乳动物的新鲜毛发和在冷冻条件下保存4个月的毛发作为材料。从毛囊中提取DNA,应用PCR方法扩增SRY基因片段,ZFX/ZFY基因片段,探讨哺乳动物性别鉴定的最优化PCR方案。结果表明,毛发DNA和血液DNA均可获得相同的扩增结果。证实了毛发作为PCR扩增材料是可靠的。对不同材料量、不同模板量、不同提取方法进行比较,优化实验方案,达到1根毛发用Chelex-100提取得到的DNA即可以成功地进行 相似文献
46.
Jin‐Long Yang Shu‐Heng Li Wei‐Yang Bao Hideki Yamada Hitoshi Kitamura 《Aquaculture Research》2015,46(1):155-162
Metamorphic responses of pediveliger larvae of Mytilus galloprovincialis to different ions were investigated through a series of bioassays. Effects of tetraethylammonium chloride (TEA) on inductive effects of these above ions were also investigated. Excess ions including Li+, Cs+, Rb+ and Ca2+ induced larval metamorphosis at 10?3 M to 5 × 10?2 M in 24‐h exposure assays. In continuous exposure assays, only excess Ca2+ showed inductive activity and induced 25% metamorphosis at 5 × 10?2 M. Larval responses to Li+ and Rb+were inhibited by TEA, while induction of metamorphosis by Cs+and Ca2+ was independent of the presence of TEA. Thus, these ions used can be useful inducers of larval metamorphosis for application in the aquaculture industry. The finding provides new insights on the biochemical mechanism controlling larval metamorphosis in this species. 相似文献
47.
格氏线虫表皮蛋白和分泌蛋白都具有抑制昆虫免疫反应的能力,能够帮助侵染期线虫侵染寄主,但两者所含蛋白组分并不相同,从而导致蛋白活性也有所差异。本研究采用乙醇萃取和昆虫匀浆诱导,分别从侵染期的格氏线虫体表及分泌物中得到了表皮蛋白和分泌蛋白,并比较了这两者之间的异同。结果表明,无论是在昆虫体内还是体外,侵染期线虫表皮蛋白和分泌蛋白都具有抑制昆虫免疫反应的生物活性,并且分泌蛋白的活性更强。本研究为进一步研究线虫侵染与昆虫免疫间的相互关系和线虫抑制昆虫免疫反应的作用机理提供了科学佐证。 相似文献
48.
质量性状和数量性状在不同水平反映了个体间的遗传差异,现有遗传相似性的度量往往割裂两者的信息.本文提出了整合质量性状和数量性状评价个体间遗传相似性的统计策略,调整的欧氏距离能有效地度量个体间的差异,并能很好地处理性状数据的缺失.实例分析了中国农业科学院、华南农学院、广东省农科院水稻生态研究室收集和调查的2262份水稻种质资源10个质量性状和15个数量性状的数据资料,用调整的欧氏距离及不加权类平均法进行群体分类,多次聚类优先取样法抽取8个不同容量的巢式子集并进行遗传多样性比较.结果表明:基于整合信息构建的核心种质同时具有较高的数量性状和质量性状遗传多样性;仅用质量性状信息不足以评价个体间的遗传差异;核心种质构建中应该采用数量性状的信息,同时整合质量性状的信息. 相似文献
49.
Lignin characteristics of bast fiber and core in kenaf, bark and wood of paper mulberry and mulberry
The structural features of bast fiber and core lignins in kenaf (Hibiscus cannabinus), bark and wood lignin of paper mulberry (Broussonetia papyrifera (L.) Vent × Broussonetia kazinoki Sieb.) and mulberry (Morus bombycis) were characterized by alkaline nitrobenzene oxidation, ozonation and methoxyl group determination. Bj?rkman lignins were
isolated from bast fiber and core, and bark and wood fractions of the plant samples, and structural characteristics were investigated
by 1H NMR and 13C NMR spectroscopies. Kenaf bast fiber gave very high molar ratio of syringaldehyde to vanillin (S/V) of alkaline nitrobenzene
oxidation products, while methoxyl content was about the same as that of the core fraction. Results of 1H NMR and 13C NMR of Bj?rkman lignin suggested the presence of aliphatic fragments in lignins isolated from paper mulberry and mulberry
bark, but not in kenaf bast fiber. The lower yield of alkaline nitrobenzene oxidation products from bast fiber and bark might
be due to the higher content of condensed structure of lignin compared to core fraction. Total yield of erythronic (E) and threonic (T) acids of ozonation products and the molar ratio of erythronic acid to threonic acid (E/T) of the bast fibers and bark were lower than the corresponding core and wood fractions, suggesting that the contents of arylglycerol-β-aryl
ether intermonomer linkages in the bast fiber and bark lignin were lower than those of the core and wood fractions. Methoxyl
content of bark lignin was lower than the corresponding wood lignin. The methoxyl content of the extract-free kenaf bast fiber
was similar to that of the core fraction, while the values of paper mulberry and mulberry bark were about one-half of the
corresponding wood fractions, respectively. In bark lignins, the methoxyl contents of Klason lignin and Bj?rkman lignin from
bark were lower than those of the extract-free barks. This result suggests that the purity of Klason lignin and Bj?rkman lignins
of bark may be rather low. 相似文献
50.
通过添加增效剂、正交试验设计优化PCR反应体系、联合采用多种PCR程序等措施,建立并优化了PCR扩增体系,成功地从高GC青枯菌基因组中扩增出了长度为2 434 bp且GC含量高达70.9%的aac基因。PCR反应体系为20 μL包括5%DMSO、2.5 mmol/L MgCl2、500 μmol/L dNTP、10 pmol/L引物、1.25 U Taq酶、50 ng模板DNA。首先采用热启动PCR:95 ℃5 min,保持80 ℃,加入Taq酶;然后采用二步PCR:5个循环包括变性95 ℃1 min,65 ℃1 min;最后采用降落PCR:30个循环为95 ℃1 min,78 ℃1 min,每个循环降低0.5 ℃,72 ℃3 min;补充10个循环为95 ℃ 1 min,63 ℃1 min,72 ℃3 min;72 ℃10 min。该试验体系的建立与优化为研究高GC含量生物的基因功能提供了方法。 相似文献