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Application of PCA and HCA to the Structure-activity Relationship(SAR) Study of Fluoroquinolones 被引量:1
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作者 LI Xiao-Hong ZHANG Rui-Zhou +1 位作者 CHENG Xin-Lu YANG Xiang-Dong 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第11期1351-1358,共8页
Density functional theory (DFT) was used to calculate a set of molecular descri ptors (properties) for 14 fluoroquinolones with anti-B.fragilis activity. Principal component analysis (PCA) and hierarchical clust... Density functional theory (DFT) was used to calculate a set of molecular descri ptors (properties) for 14 fluoroquinolones with anti-B.fragilis activity. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed in order to reduce dimensionality and investigate which subset of variables should be more effective for classifying fluoroquinolones according to their an-B.fragilis activity degree. The PCA shows that the variables of ELUMO, AEHL, μ, Q2, Q3, Q5, Q6, QB, LogP, MR and MP are responsible for the separation between compounds with higher and lower anti-B.fragilis activities. The HCA results are similar to those obtained with PCA. By using the chemometric results, 4 synthetic compounds were analyzed through PCA and HCA, and 2 of them are proposed as active molecules against B.fragilis, which is consistent with the results of clinic experiments. The methodologies of PCA and HCA provide a reliable rule for classifying new fluoroquinolones with anti-B.fragilis activity. 展开更多
关键词 structure-activity relationship DFT PCA HCA
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An Upper Bound for the Number of Normalized Latin Square
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作者 DUAN Lian 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2006年第4期585-589,共5页
In this note, the author find an upper bound formula for the number of the p × p normalized Latin Square,the first row and column of which are both standard order 1, 2,…p.
关键词 Latin square normalized latin square inclusion-exclusion principe
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