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Here we describe a new record of a sauropod dinosaur from the Lower Cretaceous (Hauterivian–Barremian) Rio Piranhas Formation, Sousa Basin, NE Brazil. Dinosaur fossil bones from this deposit were unknown until now. Thus, the discovery of a sauropod fibula from this locality is highly significant. Our discovery represents an indeterminate titanosaur and the earliest stratigraphic occurrence of this group in central Gondwana. When compared to chronocorrelate titanosaur trackmakers of this geological unit, this fossil specimen appears substantially smaller. Histological analysis of the fibula suggests that this is a relatively young individual (approximately 40–50% adult body size) that had passed its most rapid phase of early juvenile growth, but had not yet attained somatic maturity. Thus, the fibula recovered is from a young individual rather than from a small-bodied adult titanosaur. 相似文献
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顾本立 《CT理论与应用研究》1994,3(1):1-5
骨质疏松症是一种常见的代谢性骨病，其诊断的主要依据为骨密度降低。目前的测量骨密度方法在精度、剂量方面不很理想．本文介绍一种外周型高精度小型ＣＴ，精度高、剂量低是一种较理想的测定骨密度的仪器。文中介绍了提高精度和降低剂量的措施，以及仪器在临床应用试验的情况和结果，此仪器并可扩展应用于骨结构分析。 相似文献
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西北太平洋区域纬向风垂直切变的变化是影响西北太平洋热带气旋生成和发展的一个重要的动力因子,弱的纬向风切变有利于热带气旋的发生、发展。文中将西北太平洋区域纬向风垂直切变幅度(MWS)定义为850与200 hPa的纬向风之差的绝对值,以研究MWS的气候特征。结果表明,西北太平洋区域的MWS有两个主要空间模态,第1空间模态表现为在15°N以南的热带西太平洋存在MWS东西向变化相反的两个区域,20°N附近的热带西太平洋MWS的变化与其以北海区的MWS的变化相反。第2空间模态表现为在热带太平洋140°E东、西的变化相反。研究了两个模态相关的大气环流特征,发现去掉强ENSO信号后,第1模态不但与低纬度大气环流有关,而且还与南、北半球中高纬度的大气环流有关,第2模态主要与热带西太平洋和北太平洋局地大气环流有关。另外,第1模态的时间系数与赤道东太平洋海温、西北太平洋台风生成频次有着密切联系;第2模态时间系数与西北太平洋台风活动频次联系密切。 相似文献
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The long bone histology of a Late Cretaceous eusuchian crocodyliform from the Iberian Peninsula reveals clear variations in the cortical structure which reflects changes in the speed of bone deposition (i.e., skeletal growth) related to ontogeny. The presence of secondary woven-fibred bone tissue in the perimedullar region of the cortex, and the existence of an external fundamental system in the most external periostic cortex, which is a proxy for somatic maturity and effective cessation of growth, challenges the former idea that the growth strategy of extinct crocodylians fit in the typical ectotherm condition, according to which these animals grew slowly during life under an indeterminate growth strategy. The analysed specimen lived for a minimum of 16 years and the highest preserved apposition rates took place in an advanced ontogenetic stage. The study suggests that the general aspects of the modern crocodylian growth strategy were already in place in some lineages by the Cretaceous. 相似文献
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目的 研究鞘内注射细胞外调节蛋白激酶（ERK1/2）抑制剂（SCH772984）对骨癌痛Sprague-Dawley（SD）大鼠疼痛行为学及脊髓背角Fos蛋白表达的影响,探讨ERK-P90RSK-Fos信号通路在骨癌痛中的作用。方法 取鞘内置管后5天的雌性SD大鼠40只,随机分成5组（n=8）,包括Sham假手术组和BNP模型组（分别为对照组,SCH772984给药组SCH 0.1组,SCH 1组,SCH 10组）。在造模后第9天,Sham组不给药,BNP模型组鞘内分别给5% DMSO 10μl、SCH772984抑制剂 0.1、1.0、10μg（SCH772984抑制剂溶于10μl 5%的DMSO中）。测定造模前1天、造模后3、6、9、12、15、18天以及给药后1、3、6、9、12、18、24h的机械缩足阈值（MWT）、热缩足潜伏期（PWL）以及2min自发缩足次数。取鞘内置管后5天的SD大鼠40只,随机分为5组（n=8）,其中B1、B2、B3组在造模后第9天,鞘内注射SCH772984抑制剂10μg后分别于1、9、24h取材,M组为模型对照组,鞘内注射5% DMSO后9h取材,S组为空白对照组。通过免疫印迹（Western blot）法及免疫荧光测定脊髓背角p-ERK、p-p90RSK以及Fos蛋白表达情况。结果 鞘内注射ERK1/2抑制剂（SCH772984）对骨癌痛大鼠有镇痛作用,并且该效应随着剂量的增加而增大;鞘内注射ERK1/2抑制剂（SCH772984）10μg可明显减少脊髓背角Fos蛋白的表达。结论 ERK-p90RSK-Fos通路可能影响骨癌痛。 相似文献
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为了提高对面部和颅底骨折的认为。本组７４例，男性６３例，女性１１例，年龄２－７１岁，车祸外伤６４例，拳击伤５例，铁棍击伤２例，从高处跌下３例，全部病例均采用轴位ＣＴ平扫。眶内壁骨折２０例，其中爆裂骨的１１例，直接骨折８例，１列同时受直接和间接外力作用；眶下壁骨折１例，为爆裂骨折；眶外后壁骨折１例，眶顶壁骨折９例，均为直接骨折；其他骨折３３例；蝶窦内液平为颅底骨折的重要间接征象。ＣＴ检查可确定骨折类 相似文献
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Hongcang ZHOU 《中国地球化学学报》2006,25(B08):54-55
Direct coal combustion not only has a low utilizing efficiency, but also produces a large amount of pollutants such as particulate, CO2, SO2, NOx, polycyclic aromatic hydrocarbons （PAHs）, PCDD/PCDFs, and so on. Coal gasification is a clean coal technology that presents good prospects for coal use, mainly for producing electricity with a high coal conversion efficiency and low environmental impact. However, there is a problem about the minimization of PAHs in coal gasification or direct coal combustion. PAHs are harmful to the environment and human health due to their high degree of mutagenicity and carcinogenicity when they enter human bodies through breathing, eating, and drinking. It is said that about 75%-90% cancers of human beings are mainly caused by PAHs. So the US EPA has prioritized 16 PAH compounds as hazardous air pollutants; these compounds are naphthalene （NAP）, acenaphthylene （AcPy）, acenaphthene （AcP）, fluorene （Flu）, phenanthrene （PhA）, anthracene （ANT）, fluoranthene （FluA）, pyrene （Pyr）, benzo （a） anthracene （BaA）, chrysene （Chr）, benzo （b） fluoranthene （BbF）, benzo （k） fluoranthene （BkF）, benzo （a） pyrene （BaP）, indeno（1,2,3,-cd） pyrene [In（1,2,3-cd） P], dibenzo （a,h） anthracene （DbA）, and benzo （ghi） perylene （BghiP）. The residual char is one of the main products during coal gasification, and then it is brought into the combustion chamber to combust. To investigate the distribution of PAHs in fly ash, the combustion of coal and residual char was tested in a pressurized spouted fluidized bed. After Soxhlet extraction and K-D concentration, the contents of 16 PAHs recommended by US EPA in coal, residual char, and fly ash, were analyzed by a HPLC coupled with fluorescence and diode-array detection. 相似文献
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探讨螺旋ＣＴ在临床应用价值,选择部分典型病例３０例,其中血客性病变或螺及血管的病变８例,骨病变２１例,胆道病变１例,扫描机为Ｐｈｉｌｉｐａ Ｔｏｍｏｓｃａｎ Ａｖｅｐ。血管成像为主的,选择２－５ｍｍ的准直器宽度和床速,１２ｍｍ间隔重建,其它病变选择５－７ｍｍ的准直器宽度和床速,２－３ｍｍ间隔重建,增强扫描使用６０％的碘造影剂８０－１２０ｍｌ,以脏静脑用高压注射器注入,速率３ｍｌ／ｓ,脑血管和腹腔建 相似文献