首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   91篇
  完全免费   19篇
  药学   110篇
  2019年   1篇
  2018年   13篇
  2017年   9篇
  2016年   4篇
  2015年   10篇
  2014年   11篇
  2013年   9篇
  2012年   7篇
  2011年   13篇
  2010年   12篇
  2009年   2篇
  2008年   7篇
  2007年   6篇
  2006年   3篇
  2005年   3篇
排序方式: 共有110条查询结果,搜索用时 31 毫秒
1.
代谢组学研究中数据处理新方法的应用   总被引:16,自引:0,他引:16  
目的探索代谢组学研究中数据处理的新方法。方法本文提出了在代谢组学数据预处理中,用稳健PCA的方法进行离群样品点的诊断,用变量的类内差异和类间差异的比较来判断非保守性代谢组分,用尺度同一化的方法进行数据预处理来消除数据的尺度差异。并以Arabidopsis thaliana属的四个基因型的植株代谢组学的数据为例,用以上的方法进行数据预处理后再用PCA的方法分析。结果与结论研究表明这三种数据预处理方法的应用会明显的改善代谢组学生物信息学分析中聚类分析的结果和生物标志物识别的准确性及全面性。  相似文献
2.
Metabonomics in toxicology: a review.   总被引:12,自引:0,他引:12  
Metabonomics and its many pseudonyms (metabolomics, metabolic profiling, etc.) have exploded onto the scientific scene in the past 2 to 3 years. Nowhere has the impact been more profound than within the toxicology community. Within this community there exists a great deal of uncertainty about whether metabonomics is something to count on or just the most recent technological flash in the pan. Much of the uncertainty is due to unfamiliarity with analytical and chemometric facets of the technology and the attendant fear of any "black-box." With those fears in mind, metabonomics technology is reviewed with particular emphasis on toxicologic applications in preclinical drug development. The jargon, logistics, and applications of the technology are covered in some detail with emphasis on recent work in the field.  相似文献
3.
This paper compares the performance of two recently developed algorithms and methods for peak alignment of first-order NMR data of complex biological samples. The NMR spectra of such samples exhibit variations in peak position and peak shape due to variations in the sample matrix and to instrumental instabilities. The first method comprises an alignment of spectral segments with linear interpolation and shift correction to accommodate correspondence between a target and a test spectrum by a beam search or genetic algorithm. The second method is based on peak picking and needle vector representation of the NMR data with subsequent breadth-first search to establish shift corrections between the target and the test spectrum.

The two proposed peak alignment methods and their respective merits are discussed for a real metabonomics application. Both alignment methods have been shown to enhance the interpretability of the resulting multivariate models, thereby increasing the prospect of detecting and following the onset of subtle biological changes reflected in the NMR data.  相似文献

4.
高血压病中医分型的代谢组学研究   总被引:8,自引:0,他引:8  
目的:将传统中医辨证方法同现代系统生物学理论相结合,探讨原发性高血压辨证分型与基于GC/MS的血清代谢组学的关系。方法:原发性高血压辨证分为肝火亢盛、痰湿雍盛及阴虚阳亢三型。应用GC/MS测定健康人及原发性高血压病人血清内源性代谢物,并用主成分分析(PCA)、偏最小乘方分析(PLS-DA)和马氏距离(MD)分析他们的代谢谱。结果:PCA和PLS-DA分析的结果表明:健康人与高血压病人血清代谢谱有明显差异,能够被区分开,但PCA和PLS-DA不能将中医高血压的三型完全分开。利用MD不仅可以清晰地区分上述三种类型的高血压,同时还显示高血压的发展过程。结论:基于GC/MS和模式识别的代谢组学在揭示传统中医理论本质上有着广泛的应用前景。  相似文献
5.
6.
代谢组学数据处理方法——主成分分析   总被引:6,自引:0,他引:6  
代谢组学在生命科学领域得到了越来越广泛的应用并展现出良好的前景。代谢组学分析产生的含有大量变量的数据难以用常规方法进行分析,如何正确分析和解释代谢组学的数据是研究的关键。本文主要介绍了在代谢组学数据分析中占主导地位的主成分分析基本方法,旨在加强代谢组学数据分析的基础知识并规范数据分析的方法。  相似文献
7.
药物分析信息学的理论研究与实践探索   总被引:3,自引:0,他引:3  
目的:介绍药物分析信息学的理论和应用。方法:从药物分析信息的解析与挖掘、新型智能化分析仪器的研发、药物分析信息学的最新应用等方面进行阐述。结果:药物分析信息学已取得一定进展,并在分析信息解析、分析仪器智能化、代谢组学研究等方面发挥重要作用。结论:药物分析信息学已成为现代药物分析学科中的重要内容。  相似文献
8.
The alkaloid arecoline is a main constituent of areca nuts that are chewed by approximately 600 million persons worldwide. A principal metabolite of arecoline is arecoline 1-oxide whose metabolism has been poorly studied. To redress this, synthetic (+/-)-arecoline 1-oxide was administered to mice (20mg/kg p.o.) and a metabolomic study performed on 0-12h urine using ultra-performance liquid chromatography-coupled time-of-flight mass spectrometry (UPLC-TOFMS) with multivariate data analysis. A total of 16 mass/retention time pairs yielded 13 metabolites of (+/-)-arecoline 1-oxide, most of them novel. Identity of metabolites was confirmed by tandem mass spectrometry. The principal pathways of metabolism of (+/-)-arecoline 1-oxide were mercapturic acid formation, with catabolism to mercaptan and methylmercaptan metabolites, apparent CC double-bond reduction, carboxylic acid reduction to the aldehyde (a novel pathway in mammals), N-oxide reduction, and de-esterification. Relative percentages of metabolites were determined directly from the metabolomic data. Approximately, 50% of the urinary metabolites corresponded to unchanged (+/-)-arecoline 1-oxide, 25% to other N-oxide metabolites, while approximately, 30% corresponded to mercapturic acids or their metabolites. Many metabolites, principally mercapturic acids and their derivatives, were excreted as diastereomers that could be resolved by UPLC-TOFMS. Arecoline was converted to arecoline 1-oxide in vitro by human flavin-containing monooxygenases FMO1 (K(M): 13.6+/-4.9muM; V(MAX): 0.114+/-0.01nmolmin(-1)microg(-1) protein) and FMO3 (K(M): 44.5+/-8.0microM; V(MAX): 0.014+/-0.001nmolmin(-1)microg(-1) protein), but not by FMO5 or any of 11 human cytochromes P450. This report underscores the power of metabolomics in drug metabolite mining.  相似文献
9.
The highly directional maternal-to-fetal transfer of essential fatty acids (EFAs) across the placenta plays a critical role in guiding proper fetal development. Exposure to xenobiotics that may alter the fetal supply of EFAs/lipids could lead to fetal toxicity. Since the placenta is the first fetal arising organ that regulates fetal fatty acid homeostasis, the fatty acid/lipid composition in the placenta may serve as an indicator of fetal composition. In this study, we investigated the effects of the peroxisome proliferator chemical di-(2-ethylhexyl)-phthalate (DEHP), a widely used plasticizer and ubiquitous environmental contaminant, and its selective metabolites, mono-(2-ethylhexyl)-phthalate (MEHP) and 2-ethylhexanoic acid (EHA) on the lipid metabolome in a rat HRP-1 trophoblast model. The concentrations of ten lipid classes (cholesterol esters, diacylglycerol, triacylglycerides, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, lysophosphatidylcholine, cardiolipin, and sphingomyelin) were determined, as well as the individual fatty acid compositions, especially the ω-3 and ω-6 family of EFAs. The level of each lipid class was significantly increased upon exposure to the agents, with MEHP and EHA generally showing higher increases than DEHP. The same trends were observed in comparing the fatty acid compositions. For example, the ω-3/ω-6 fatty acids ratio did not change, although the levels of ω-3 and ω-6 fatty acids were significantly elevated upon exposure. These results suggest that DEHP and its metabolites can alter lipid metabolome in a rat placental cell line, implying that these compounds may contribute to aberrant placental EFA/lipid homeostasis caused by peroxisome proliferation, and potentially result in abnormal fetal development.  相似文献
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号