摘要:

The present work is an overview of the levels of contamination of 92 macromycetes by 15 metals. Data were collected around Paris (France) in 1989 and 1990. A progressive approach involving the use of univariate followed by multivariate statistical analyses allowed to fully exploit the resulting data matrix. Thus, conclusions regarding the origin of the metals, the toxicological implications and the possible use of mushrooms as environmental markers of pollutions are drawn.

ISSN:1062-936X    

DOI:10.1080/10629369908039104

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In an earlier studyQuant. Struct.-Act. Relat.1996, 15, 403–409 comparing the performance of 14 log P predictors it was concluded that predictions of log P values were significantly better for simple organic molecules than for drugs. Since the publication of this benchmark study, a log P predictor, VLOGP, has been developed in our group. In the work presented here. VLOGP is used to assess the log P values of the same 48 drugs as included in the benchmark comparison. VLOGP returned 79.2% “acceptable”. 18.6% “disputable”, and only 2.2% “unacceptable” log P values. The “acceptable”, “disputable”, and “unacceptable” log P values from the 14 other predictors, respectively, ranged between 27.1% and 72.9%, 16.7% and 41.7%, and 2.2% and 37.5%. Further, VLOGP resulted in a much tighter fit (mean squared deviation. m.s.d., = 0.197) between experimental and calculated values of log P compared with the other 14 methods for which the m.s.d. ranged between 0.247 and 1.068. The major differentiation between VLOGP and other predictors is that its application domain, called Optimum Prediction Space (OPS), is quantitatively defined,i.e., the structures to which VLOGP model should not be applied for predicting log P can be identified. This process is automated by implementation of VLOGP in the TOPKAT package.

ISSN:1062-936X    

DOI:10.1080/10629369908039105

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In the present paper we investigate the trees with the sameJJindex (calledJJ-equivalent trees). The topological indexJJis derived from the so called Wiener matrix introduced by Randicet al., in 1994. The Wiener matrix is constructed by generalizing the procedure of Wiener for evaluation of Wiener numbers in alkanes. From such matrices several novel structural invariants of potential interest in structure-property studies were obtained. These include higher Wiener numbers, Wiener sequences, and hyper-Wiener number,etc.The topological indexJJis constructed by considering the row sums of the Wiener matrix. A construction method for a class ofJJ-equivalent trees is given. By using this method we construct the smallest pairs of non-isomorphicJJ-equivalent trees which have 18 vertices. In addition we report on groups of 3,4, and 6 non-isomorphicJJ-equivalent trees. The smallest such trees are of size 28 for triples and quadruples, and 34 for the group of 6 elements.

ISSN:1062-936X    

DOI:10.1080/10629369908039106

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:1062-936X    

DOI:10.1080/10629369908039107

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:1062-936X    

DOI:10.1080/10629369908039103

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor