Implementation of artificial intelligence for automatic drug design. I. Stepwise computation of the interactive drug-design sequence

In this article we represent the development of an artificial-intelligence-based method for the automatic design of valid chemical structures (AISD). The key feature of the proposed algorithm is its ability to mimic many decision-making processes carried by the human drug designer during a design session. The manual drug-design process is analyzed and transformed into a computerized form by associating a weight factor with each term. These weights enable the translation of the drug designer's intution into probabilities that control the flow of the design process. The input required to initiate a design session might be as minimal as the geometry of a previously existed pharmacophoric model, up to the three-dimensional geometry of the host receptor. A design application is demonstrated by the implementation of the proposed algorithm for the design of new potent sweeteners. © 1994 by John Wiley & Sons, Inc.     

Molecular and crystal structures of a class of push-pull quinonoid compounds with potential nonlinear optical applications

Molecular and crystal structures of three compounds with electron donor-conjugation unit-electron acceptor framework are reported where the conjugation unit is formally a quinonoid ring. Semiempirical quantum chemical calculations indicate large hyperpolarizabilities in these push-pull molecules. Since all the crystal structures are found to belong to centrosymmetric space groups, modifications are necessary for quadratic nonlinear optical applications.     

A new partial geometry with parameters (s,t,α) = (7,8,4)

A partial geometry with parameters as given in the title is constructed by use of the 240 points closest to the origin in the lattice E₈.     

An axiom system for metasymplectic spaces

Metasymplectic spaces are geometries representing Tits' weak buildings of Type F ₄. For metasymplectic and polar spaces an axiom system is given that characterizes them in terms of points and lines.     

Eigenvalue inequalities for products of matrix exponentials

Motivated by models from stochastic population biology and statistical mechanics, we proved new inequalities of the form $\text{(1) ?(e}{}^{\mathrm{A}}\text{e}{}^{\mathrm{B}}\text{)??(e}{}^{\mathrm{A+B}}\text{)}$, where A and B are n × n complex matrices, 1<n<∞, and ? is a real-valued continuous function of the eigenvalues of its matrix argument. For example, if A is essentially nonnegative, B is diagonal real, and ? is the spectral radius, then (1) holds; if in addition A is irreducible and B has at least two different diagonal elements, then the inequality (1) is strict. The proof uses Kingman's theorem on the log-convexity of the spectral radius, Lie's product formula, and perturbation theory. We conclude with conjectures.