332 resultados para 1358
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<正> 文冠果属无患子科文冠果属植物,别名文官果、文光果、木瓜等,是我国特有的一种优良木本食用油料树种。其适应性极强,根深、耐旱、耐寒、耐盐碱、耐脊薄,且综合价值高。分布于我国13个省(市、自治区)。1、文冠果的食用价值文冠果的果实含有高油脂及多种生物活性成分:
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One-step synthesis of Ru (bpy)(3) Cl-2-immobilized (bpy = 2,2'-bipyridine) silica nanoparticles (Ru-silica nanoparticles) for use in electrogenerated-chemiluminescence (ECL) detection is reported. Ru-silica nanoparticles are prepared by using the Stober method. Compared with free Ru(bpy)(3)Cl-2, Ru-silica nanoparticles are seen to exhibit a red-shift of the UV-vis absorbance peak and a longer fluorescence lifetime, which are attributed to the electrostatic interaction of Ru(bpy)(3)(2+) and silica. Because silica nanoparticles are used as immobilization matrices, the surfaces of Ru-silica nanoparticles are easily modified or functionalized via the assembly of other nanoparticles, such as Au. For ECL detection, Au-colloid-modified Ru-silica nanoparticles are immobilized on a 3-mercaptopropyl-trimethoxysilane-modified indium tin oxide electrode surface by Au-S interaction; the surface concentration of electroactive Ru(bpy)(3)Cl-2 is obviously higher than that in silica films.
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本文阐述了一种新的光谱电化学技术——现场显微红外光谱电化学法的反射式方法的技术特点和优势,报告了一种适于水溶剂和非水溶剂的反射式现场显微红外光谱电化学池的设计,并首次在25um直径的超微铂盘工作电极上,对Fe(CN)_6~(4-)/FE(CN)_6~(3-)进行了现场显微红外光谱电化学的测量。
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中性Π配体过渡金属,特别是钛的有机配合物的合成和结构已有较深入的研究。但是含中性Π配体的稀土有机配合物的合成研究刚刚开始。1986年,Cotton等人报道了第一个这种类型的配合物Sm(η~6C_6Me_6)(η~2AlCl_4)_3。研究中性π配体稀土有机配合物的合成、结构及性能,对于揭示f元素的成
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A marine geophysical survey was carried out, on the RN Science 1 of the Institute of Oceanography, Chinese Academy of Sciences (IOCAS), in 2000, at the Miyako Section of Okinawa Trough. Here we present seismic and acoustic evidence of a gas seep on the sea floor on the western part of the Okinawa Through, near the lower slope of the East China Sea Slope and discuss the possibility of related formation of gas hydrate. A gas column reflection was observed in echo-sounder data above a section where the sea floor reflector was missing, on both the echo-sounder and the seismic data for line H14. The seismic data also show an acoustic curtain reflection and a turbidity reflection at this section. These anomalies are the evidence of the existence of a gas seep, which occupies an area 2.2 km in diameter. Based on the acoustic curtain on line H14, we believe that the amount of gas contained in the sediments below the gas seep is larger than 1 % by volume of sediment. Tectonically, the gas seep developed in a small basin controlled by basement uplift in the north, south and east. The thickness of the sediment layer can be greater than 3.5 km. A mud diapir structure was found in layer D beneath the gas seep. Over-pressure may occur due to the large sediment thickness and also the tectonic basement uplift in the north, south, and east. The mud diapir could be the preferential pathway for methane-rich fluids. The acoustic curtain may indicate that free gas related to the gas seep can be formed on the sea floor. We also note that the layer above the acoustic curtain on profile H14 may contain gas hydrate.
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扇贝养殖是我国重要的海水养殖产业,然而自1997 年以来,养殖扇贝陆续爆发的大规模死亡,不但造成了巨大的经济损失,而且严重影响了该产业的健康发展。丝氨酸蛋白酶抑制因子及丝氨酸蛋白酶在无脊椎动物的免疫应答中起着核心作用,它们的协同作用直接导致外界病源入侵的信号转导和级联放大,并进一步激活一系列防御体系,如黑化反应、血液凝结和抗菌肽的合成等。因此,克隆扇贝参与免疫防御的丝氨酸蛋白酶抑制剂基因并对其功能进行研究,将有助于进一步研究扇贝的免疫防御机制,丰富和发展无脊椎动物免疫学的内容。 运用大规模EST技术和RACE技术从栉孔扇贝中克隆出一个Kazal型丝氨酸蛋白酶抑制剂基因,定名为CfKZSPI。该基因cDNA序列全长1788bp,其中5' 非编码区(Untranslated Region, UTR)为97 bp,3' UTR161 bp,有一个典型的多聚腺苷酸信号序列(AATAAA)和一个ploy A 尾巴,开放阅读框(Open Reading Frame, ORF)含有1530 bp,编码509 个氨基酸残基。对其推测氨基酸序列进行分析,发现其中包括22个氨基酸残基组成的信号肽序列和12个Kazal型丝氨酸蛋白酶抑制剂结构域。采用QRT-PCR(quantitative real time PCR)对鳗弧菌浸泡刺激后栉孔扇贝血淋巴中CfKZSPI 的 mRNA表达量进行了检测,发现其mRNA 的表达量在鳗弧菌刺激后3h明显上升,达到空白组的43.6倍;然后在6h时有所下降,为空白组的15.0倍;随着菌刺激时间的增长,CfKZSPI基因的 mRNA 表达量急剧增加,在刺激后8h,12h,24h分别达到空白组的174.1,207.8,675.4倍。统计分析发现3h(P=0.019<0.05)和12h(P=0.020<0.05)时,CfKZSPI基因mRNA表达量与空白组差异均显著。为了研究栉孔扇贝CfKZSPI的蛋白活性,将其第十二个结构域克隆到pET-32a(+)载体中,转化大肠杆菌Rosetta-gami(DE3)表达菌株,获得可溶性表达的蛋白rCfKZSPI-12,对其进行抑制蛋白酶活性的分析,发现其对胰蛋白酶有很强的抑制活性,而对凝血酶没有抑制活性。当rCfKZSPI-12与胰蛋白酶分子比率为1:1时,约90%的蛋白酶活性被抑制。运用狄更斯作图法研究rCfKZSPI-12对胰蛋白酶的抑制能力,结果发现其对胰蛋白酶的抑制常数为173 nmol L-1。 采用同样方法从海湾扇贝cDNA文库中克隆出一个Kunitz型丝氨酸蛋白酶抑制剂基因,定名为Aikunitz。该基因全长632 bp,其中5' UTR 为105 bp,3' UTR 为 245 bp,有一个典型的多聚腺苷酸信号序列(AATAAA)和一个ploy A 尾巴,ORF 含有282 bp,编码93 个氨基酸残基。推测的氨基酸序列N末端有一个20个氨基酸残基组成的信号肽序列,成熟蛋白包括一个Kunitz型丝氨酸蛋白酶抑制剂结构域。采用QRT-PCR对鳗弧菌和藤黄微球菌感染后海湾扇贝血淋巴中Aikunitz 的mRNA的表达量进行了检测,结果发现其在鳗弧菌刺激后3h到9h持续上升,9h时表达量为PBS对照组的4.49倍(P=0.008<0.05),然后开始下降,在72h时表达量为对照组的0.24倍(P=0.021<0.05);而在藤黄微球菌刺激后3h到12h其表达量上升,其中6h时为空白组的5.95倍(P=0.0004<0.01);12h以后迅速下降,其中24h的表达量为对照组的0.38倍(P=0.028<0.05)。将Aikunitz基因编码的成熟蛋白按照重组CfKZSPI-12的方法进行重组表达,并对重组蛋白进行抑制蛋白酶和抑菌活性分析。结果发现其对胰蛋白酶和弹性蛋白酶两种丝氨酸蛋白酶都没有抑制作用。抑菌实验同样发现,重组Aikunitz 对供试的革兰氏阳性菌藤黄微球菌和革兰氏阴性菌鳗弧菌和大肠杆菌都不显示明显抑菌活性。
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A new species of Tripogon from western China (Sichuan Province), T. debilis L. B. Cai, is described and illustrated. This species is similar to both T. chinensis (Franchet) Hackel and T sichuanicus S. M. Phillips & S. L. Chen, but distinguished from these two species by its pendent pi spikes, relatively tong glumes and lemma awns, denticulate upper glumes, and its paleas strikingly shorter than the lemmas.
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Recognizing standard computational structures (cliches) in a program can help an experienced programmer understand the program. We develop a graph parsing approach to automating program recognition in which programs and cliches are represented in an attributed graph grammar formalism and recognition is achieved by graph parsing. In studying this approach, we evaluate our representation's ability to suppress many common forms of variation which hinder recognition. We investigate the expressiveness of our graph grammar formalism for capturing programming cliches. We empirically and analytically study the computational cost of our recognition approach with respect to two medium-sized, real-world simulator programs.
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Listening to children in the field of education: experience in Wales, (2007) 19 Child and Family Law Quarterly 161-182 pp.161-182 RAE2008
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Cairns, A. J., Gallagher, J. A. (2004). Absence of turnover and futile cycling of sucrose in leaves of Lolium temulentum L.: implications for metabolic compartmentation. Planta, 219 (5), 836-846. Sponsorship: BBSRC RAE2008
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Objectives: to assess elderly patients’ dental status and dental habits and compare the survival rates, impact on patients’ quality of life and cost-effectiveness of Atraumatic Restorative Treatment (ART) and a conventional treatment (CT) to restore carious lesions in an elderly population. Methods: In this randomised clinical trial, 99 independently living adults (65-90 yrs) with carious lesions were randomly allocated to receive either ART or CT. Details of restored, missing and carious teeth were recorded and patients answered some questions about their oral hygiene and dental attendance habits. Direct and indirect costs were measured based on treatment time, materials and labour. Effectiveness was measured using restoration survival percentage after one year. The survival of restorations was assessed 6 months and one year after restoration placement by an independent examiner. Oralhealth related quality of life (OHRQoL) was assessed using the OHIP-14 at baseline and 2 months after treatment together with a global transition statement. Results: The patient sample comprised 46 (46.46%) male and 53 (53.54) female participants at baseline, with a mean age of 73.18 (SD=6.76). The mean DMFT of the entire sample was 27.10. Ninety patients and 268 restorations could be assessed after one year, 127 ART (46 patients) and 141 conventional restorations (44 patients). 93.7% and 97.2% of the restorations placed were considered successful in the ART and CT groups, respectively. The OHIP scores did not change dramatically 2 months after treatment, in either group. The global transition scale showed an improvement in overall oral health after treatment for the majority of patients. The ART were more cost-effective compared to the CT restorations. Conclusions: ART presented survival rates similar to CT after 1 year and was a more cost-effective alternative to treat the elderly.