99 resultados para 1-5
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合成了三茚基稀土配合物(η~5-C_9H_7)_3Ln·OC_4H_8(Ln=Nd、Gd、Er),经元素分析、红外光谱、水解产物核磁共振谱及质谱表征,并测得了(η~5-C_9H_7)_3Nd·OC_4H_8(1)及(η~5-C_9H_7)_3Gd·OC_4H_8(2)的晶体结构。(1)、(2)均属六方晶系,P6_3空间群,Z=2。(1)的晶体学参数为a=b=1.1843(3)nm,c=1.0304(4)nm,V=1.25165(87)nm~3,D_c=1.49g·cm~(-3),最后一致性因子R=0.049;(2)的晶体学参数a=b=1.1805(2)nm,c=1.0236(2)nm,V=1.23536(56)nm~3,D_c=1.54 g·cm~(-3),R=0.023。平均Nd-C=0.2812nm,Gd-C=0.2795nm;Nd-O=0.2557(21)nm,Gd—O=0.2459(13)nm。配合物中四氢呋喃的四个碳原子处于完全无序状态。
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本文研究了甲基膦酸二(1-甲庚)酯(简称P350)的正庚烷溶液从盐酸溶液中萃取钪(Ⅲ)、HCl和H_2O的机理。用斜率法确定了萃合物的组成为SoCl_3·3P350和3HCl·2H_2O·3P350。讨论了水相酸度、萃取剂浓度、温度对萃取平衡的影响,计算了反应的浓度平衡常数及热力学函数。研究了萃合物的红外光谱。
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1932年鲍林(Pauling)首次提出元素电负性概念,经化学家和物理学家长期运用与研究,其定义、计算方法、应用范围和理论根据等方面都得到了广泛发展与许多成功改进。
There are two 5 '-flanking regions of bkt encoding beta-carotene ketolase in Haematococcus pluvialis
Resumo:
The unicellular green alga Haematococcus pluvialis accumulates a commercially valuable astaxanthin, with levels reaching up to 4% dry weight under environmental stress. In recent years, much effort has been devoted to understanding the molecular mechanisms regulating astaxanthin biosynthetic pathways. Beta-carotene ketolase (bkt), with control being exhibited at the transcription level, plays an important role in astaxanthin biosynthesis by H. pluvialis. Here we demonstrate the presence of two separate 5'-flanking regions [1.5 kilobase (kb) and 2 kb] of bkt (bkt1 and bkt2) that possess regulatory elements similar to those of known stress-responsive genes in plants. Results of 5'-deletion constructs and transient beta-galactosidase expression assays demonstrate that there may be positive regulatory elements governing expression in the shorter promoter at -1060/-900 from the 1.5 kb 5' region, and in the longer promoter at -1838/-1219 and at -1046/ -734 from the 2 kb 5' region relative to each homologous ATG start codon. Furthermore, our present studies reveal that the first intron (+371/+497) downstream from the 1.5 kb 5' untranslated region of bkt1 may function as a negative regulatory element to regulate its own promoter.
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A 700-year record (1.0-1.5 a resolution) of the East Asian winter monsoon (EAWM), based on grain-size analysis and AMS(14)C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea (ECS), was compared with the Dongge stalagmite delta O-18 record during the mid-Holocene. The upper muddy section of Core EC2005 has been formed mainly by suspended sediments derived from the Changjiang (Yangtze) River mouth since 7.3 ka BP. High precipitation and a strengthened EAWM might have played key roles in the high sedimentation rate (1 324-1 986 cm/ka) between 5.9-5.2 ka BP. The EAWM strengthened when the Asian summer monsoon weakened, especially around 5 500 a BP, which corresponded to a worldwide cold event. The EAWM during the mid-Holocene shows statistically significant solar periodicities at 62 and 11 a. The 5 500 a BP cold event might be resulted from orbital forcing and changes in solar activity.
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SNARE蛋白家族是所有真核细胞胞吐及分泌作用中的关键因子,由其介导的运输囊泡膜与靶膜的锚靠、融合为胞内蛋白的运出提供了一条重要途径。体外试验表明,Syntaxin6-Syntaxin7-Vti1b,SNAP-23-Syntaxin4等SNARE核心蛋白之间精确的相互作用是哺乳动物巨噬细胞肿瘤坏死因子α (TNF-α)运输和分泌的必备条件,在机体非特异性免疫应答反应过程中起重要作用。 本研究受上述启示,旨在揭示SNARE蛋白在海洋鱼类免疫细胞内重要细胞因子白细胞介素1β (IL-1β)的分泌过程中的作用。参照Percoll密度梯度离心技术,从鲈鱼头肾组织分离纯化巨噬细胞进行稳定培养;利用RT-PCR方法克隆出鲈鱼t-SNARE蛋白SNAP-23和Syntaxin3的部分cDNA序列,再结合先前克隆的VAMP2和已知的鲈鱼IL-1β,TNF-α和IL-8的基因序列,设计特异性引物。利用Real-time PCR技术在mRNA水平上精确测定鲈鱼巨噬细胞中上述6种基因在革兰氏阴性菌脂多糖(LPS)分子刺激下的表达变化,发现SNAP-23基因与三种细胞因子基因的表达正相关;通过免疫印迹检测SNAP-23蛋白表达变化,利用酶联免疫吸附试验(ELISA)检测IL-1β的分泌水平,在蛋白水平上验证了SNAP-23表达与IL-1β分泌的正相关性;利用5`RACE和3`RACE技术克隆出鲈鱼SNAP-23全长基因,结合定点突变策略和靶向PCR克隆手段,构建鲈鱼SNAP-23野生型融合质粒pEGFP-SNAP-23wt,Cys缺失突变融合质粒pEGFP-SNAP-23ΔCys和模拟E型肉毒神经毒素(BoNT/E)切割突变融合质粒pEGFP-SNAP-23ΔBoNT/E,以及鲈鱼IL-1β野生型融合表达质粒IL-1β-pEGFP和IL-1β-pEYFP。所有融合蛋白均在鲈鱼巨噬细胞内成功表达,结合ELISA实验结果发现,SNAP-23野生型的表达对IL-1β的分泌有促进作用,而Cys缺失突变体的表达则抑制IL-1β向胞外分泌。首次证实了鱼类巨噬细胞内SNAP-23蛋白在IL-1β分泌过程中的重要作用。此外通过与GFP共表达,定位了IL-1β分子在巨噬细胞内的分布,发现新合成的IL-1β分子很可能像TNFα一样经“内质网-胞质-伪足-胞外” 的分泌路径运出胞外。
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In order to discover the distribution law of the remaining oil, the paper focuses on the quantitative characterization of the reservoir heterogeneity and the distribution law of the fluid barrier and interbed, based on fine geological study of the reservoir in Liuhuall-1 oil field. The refined quantitative reservoir geological model has been established by means of the study of core analysis, logging evaluation on vertical well and parallel well, and seismic interpretation and prediction. Utilizing a comprehensive technology combining dynamic data with static data, the distribution characteristics, formation condition and controlling factors of remaining oil in Liuhuall-1 oil field have been illustrated. The study plays an important role in the enrichment regions of the remaining oil and gives scientific direction for the next development of the remaining oil. Several achievements have been obtained as follows: l.On the basis of the study of reservoir division and correlation,eight lithohorizons (layer A, B_1, B_2, B_3, C, D, E, and F) from the top to the bottom of the reservoir are discriminated. The reef facies is subdivided into reef-core facies, fore-reef facies and backreef facies. These three subfacies are further subdivided into five microfacies: coral algal limestone, coralgal micrite, coral algal clastic limestone, bioclastic limestone and foraminiferal limestone. In order to illustrate the distribution law of remaining oil in high watercut period, the stratigraphic structure model and sedimentary model are reconstructed. 2.1n order to research intra-layer, inter-layer and plane reservoir heterogeneity, a new method to characterize reservoir heterogeneity by using IRH (Index of Reservoir Heterogeneity) is introduced. The result indicates that reservoir heterogeneity is medium in layer B_1 and B_3, hard in layer A, B_2, C, E, poor in layer D. 3.Based on the study of the distribution law of fluid barrier and interbed, the effect of fluid battier and interbed on fluid seepage is revealed. Fluid barrier and interbed is abundant in layer A, which control the distribution of crude oil in reservoir. Fluid barrier and interbed is abundant relatively in layer B_2,C and E, which control the spill movement of the bottom water. Layer B_1, B_3 and D tend to be waterflooded due to fluid barrier and interbed is poor. 4.Based on the analysis of reservoir heterogeneity, fluid barrier and interbed and the distribution of bottom water, four contributing regions are discovered. The main lies on the north of well LH11-1A. Two minors lie on the east of well LH11-1-3 and between well LH11-1-3 and well LH11-1-5. The last one lies in layer E in which the interbed is discontinuous. 5.The parameters of reservoir and fluid are obtained recurring to core analysis, logging evaluation on vertical well and parallel well, and seismic interpretation and prediction. Theses parameters provide data for the quantitative characterization of the reservoir heterogeneity and the distribution law of the fluid barrier and interbed. 6.1n the paper, an integrated method about the distribution prediction of remaining oil is put forward on basis of refined reservoir geological model and reservoir numerical simulation. The precision in history match and prediction of remaining oil is improved greatly. The integrated study embodies latest trend in this research field. 7.It is shown that the enrichment of the remaining oil with high watercut in Liuhua 11-1 oil field is influenced by reservoir heterogeneity, fluid barrier and interbed, sealing property of fault, driving manner of bottom water and exploitation manner of parallel well. 8.Using microfacies, IRH, reservoir structure, effective thickness, physical property of reservoir, distribution of fluid barrier and interbed, the analysis of oil and water movement and production data, twelve new sidetracked holes are proposed and demonstrated. The result is favorable to instruct oil field development and have gotten a good effect.
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Research on naïve biology investigates children spontaneous understanding of biology objects, phenomena and function. Previous researches focus mostly on biology phenomena. Little has done on organism’s function, such as eating food. Many research in this field found that children were unable to categorize food by nutrition criterion, but rely on physical cues. In order to investigate the development of children’s naïve understanding of food and to find if they can classify food by nutrition criterion, three age groups (5-year-olds, 7-year-olds, and 9-year-olds) were included in this study. Varies experimental tasks were also used to explore the children’s understanding of food and its function. The results showed as the followings: 1) A few 5-year- old children can classify food by nutrition criterion when they take the spontaneous classification task. However, more and more children can realize what make a kind of food different from another can be the nutrition it contains. 2) Kindergarteners can find the relation between food and its output. When they become older, more and more children can explain the relation by consistent theory. It can be said that 9-year-old children have already have a profound understanding of nutrition. They gradually developed naive theory of biology on nutrition level. 3) Even kindergarteners can understand the concept of “food balance”. However, with development there was a significant age increase in food balance choice. 4) Children’s knowledge of food balance grows with age, but urban and rural educational background influence cognitive performance.
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Research on children's naive concepts has previously tended to focus on the domains of physics and psychology, but more recently attention has turned to conceptual development in biology as a core domain of knowledge. Because of its familiarity, illness has been a popular topic for researchers in this domain. However, they have only studied the children’s understanding of its causes. Other aspects of illness, such as treatment and prognosis, have received little attention. This research addresses the development of 5- to 9-year-old children’s understanding of the causes of illness and their probabilities via open-ended and forced choice interviews. The results of this research are: 1) Most of the 5- to 7-year-old children used behavioral causes to explain illness, and the 9-year-old children primarily used biological causes to interpret illness. With age, more and more children selected psychological causes to explain illness. 2) Pre-school children did not over-generalize contagions to non-contagious illnesses. They used behavioral and biological causes to explain contagious illnesses. For non-contagious illnesses, they chose only behavioral causes. 3) Most of the children used only one kind of cause to explain illness. 4) Some preschool-aged children viewed outcomes of familiar causes of illness as probabilistic. With age, more and more could make uncertain predictions of illness. 5) The children’s understanding of the causes’ probabilities appeared to be based on naïve biology. 5- to 9-year-old children often made probabilistic predictions by analyzing a single cause of illness. 6) Children coming from higher educational backgrounds outperformed their counterparts coming from lower educational backgrounds with respect to understanding illness. 7) Specific knowledge acquired could generally improved the preschoolers’ understanding of causes of illness and their probabilities.