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21.
采用人胎盘泌乳素(hPL)-亲和层析和抗人血清抗体-亲和层析技术,从胎盘匀浆中提取hPL纯品,经圆盘电泳、免疫电泳及交叉试验证实为单一成分。溴化氰水解后的产物,以高效液相色谱分析。分离出7个肽链片断峰,分别用hPL和人生长激素(hGH)放免法检测其活性,其中第6肽链片断无hGH免疫活性,若用此片断制备特异抗体,可避免与hGH出现交叉反应。 相似文献
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The essential fatty acids do not have identical roles in nutrition. Linoleic acid (LA) accumulates throughout the body of
most mammals, whereas α-linolenic acid (ALA) is rarely found in tissue lipids to the same extent as LA. It has been argued
that this is the result of metabolism of ALA to docosahexaenoic acid (DHA) or that ALA is rapidly β-oxidized to acetyl CoA
and CO2. In this study, we consider the effect of high and low ALA levels on the tissue distribution of ALA and other n-3 polyunsaturated
fatty acids (PUFA) in all tissues. Guinea pigs were fed one of two defined diets for 3 wk from wearning with both diets containing
1.8% (by weight) of LA and either 1.7% ALA or 0.03% ALA. The high ALA diet was associated with significantly increased ALA
levels in all tissues except the brain and significantly increased levels of long-chain n-3 PUFA in all tissues except intestines,
brain, carcass, and skin. The long-chain n-3 PUFA content of the whole body was less than 5% of that of the ALA content in
both diet groups, and the major long-chain n-3 PUFA (>66% of total) in the body was 22∶5n−3. The brain was the only tissue
where the DHA content exceeded that of 22∶5n−3. On the low ALA diet, there appeared to be conservation of ALA based on a comparison
of the ratio of LA to ALA in the tissues compared with that in the diet. On the high ALA diet there was a loss of ALA relative
to LA in the tissues compared with the diet. These studies suggest that the low levels of tissue ALA in the guinea pig are
likely the result of β-oxidation or excretion via the skin and fur rather than metabolism to DHA. 相似文献
24.
The study of collective user behaviours in social networking sites has become an increasing important topic in social media mining. Understanding such behaviours has its potential to extract actionable patterns that can be beneficial to develop effective marketing strategies, optimise user experiences and maximise website revenues. With the rapid development of micro-blogging, Twitter has become a richer source of intelligence that can be used to study collective user behaviour, due to its efficient and meaningful user-to-user interactions. However, the classical statistical methods have some drawbacks in bridging the gap between user-generated data and human analysts who mostly use linguistic terms to analyse data and model/summarise knowledge learned. To address this gap, this work proposes a new approach, which employs the mass assignment theory-based fuzzy association rules algorithm (MASS-FARM), for the first time, to extract useful interaction behaviour of Twitter users. The influential factors (including activity time, number of friends/followers and the number of tweets) are represented as fuzzy granules, and the associations amongst are studied by employing MASS-FARM. The collective user behaviours are analysed in the Reply category and the Non-Reply category, respectively. The applicability and usefulness of the proposed method are demonstrated via an empirical study on a collected Twitter data set. The derived results are also discussed and compared with existing works. 相似文献
25.
阐述了塑料结构壁管的基本情况和国内外现状.重点就扬子石油化工股份有限公司研究院研制的聚丙烯结构壁管专用料的情况进行了介绍。 相似文献
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Changhui Ni Jun Yan Gengdong Cheng Xu Guo 《Structural and Multidisciplinary Optimization》2014,50(1):113-128
The present paper studies the integrated size and topology optimization of skeletal structures under natural frequency constraints. It is found that, unlike the conventional compliance-oriented topology optimization problems, the considered problem may be strongly singular in the sense that the corresponding feasible domain may be disconnected and the global optimal solutions are often located at the tips of some separated low dimensional sub-domains when the cross-sectional areas of the structural components are used as design variables. As in the case of stress-constrained topology optimization, this unpleasant behavior may prevent the gradient-based numerical optimization algorithms from finding the true optimal topologies. To overcome the difficulties posed by the strongly singular optima, some particular forms of area/moment of inertia-density interpolation schemes, which can restore the connectedness of the feasible domain, are proposed. Based on the proposed optimization model, the probability of finding the strongly singular optimum with gradient-based algorithms can be increased. Numerical examples demonstrate the effectiveness of the proposed approach. 相似文献
28.
付文忠 《重庆科技学院学报(社会科学版)》2010,(15):51-53
刑事近代学派在批判刑事古典学派的基础上提出的刑罚个别化主张,对于预防犯罪和实现司法实践活动中的个别公正具有不可替代的作用.人身危险性是刑罚个别化原则的核心概念.分析了人身危险性与初犯可能性、主观恶性的关系,阐述了刑罚个别化原则的理论依据以及刑罚个别化原则与罪刑相适应原则的冲突,认为应该在罪与刑相适应的基础上,用人身危险性加以调整、修正,在一般预防和报应主义下,考虑刑罚的个别预防. 相似文献
29.
文章力图以VR(虚拟现实)技术手段应用于城市地下步行商业街规划设计,来解决当前传统规划手段地下步行商业街规划中普遍存在的对其心理环境构筑的忽视和考虑不完善的诟病,以期最大限度消除规划设计中消极空间的产生,并对其关键技术进行了研究和探讨 相似文献
30.