GTI-simplex is a new methodology that combines the generalized topological indices and the down hill simplex optimization procedure to search for optimized quantitative structure-property relationship models (Chem. Phys. Lett. 2005, 410, 343). In this study, the fundamental role of the graph topological distance inducing a local shell structure on vertexes and a detailed derivation of the GTI-d...

Geometric objects are often represented approximately in terms of a finite set of points in three-dimensional Euclidean space. In this paper, we extend this representation to what we call labeled point clouds. A labeled point cloud is a finite set of points, where each point is not only associated with a position in three-dimensional space, but also with a discrete class label that represents a...

Assessing the selective influence of amino acid properties is important in understanding evolution at the molecular level. A collection of methods and models has been developed in recent years to determine if amino acid sites in a given DNA sequence alignment display substitutions that are altering or conserving a prespecified set of amino acid properties. Residues showing an elevated number of...

The aims of this study were to improve in vitro dissolution property of poorly water-soluble everolimus (EVR) for enhanced bioavailability without using organic solvents and characterize the effects of microfluidization and freeze-drying on physicochemical properties of EVR nanosuspension and nanoparticle, respectively. EVR nanosuspension was prepared using microfluidization with various types ...

objective(s): a fast and reliable evaluation of the binding energy from a single conformation of a molecular complex is an important practical task. artificial neural networks (anns) are strong tools for predicting nonlinear functions which are used in this paper to predict binding energy. we proposed a structure that obtains binding energy using physicochemical molecular descriptions of the se...

Problem statement: Since the earliest publication on the technique, Reversed-Flow Gas Chromatography (RF-GC) has been used to determine physicochemical properties by measuring the value of one in the presence of another. The method is precise, accurate and simple compared to other conventional techniques. Approach: The experimental setup consists of a small modification of a commercial gas chro...

We have developed a modular pair of laboratory experiments for use both in undergraduate physical chemistry and biochemistry. Both laboratories examine the thermodynamics of the binding of a small molecule, eosin, to the protein lysozyme. The assay for binding is the quenching of lysozyme fluorescence by eosin through resonant energy transfer. In both experiments students measure fluorescence q...

Physical chemistry describes systems in terms of their energy and their boundary conditions. Quantitative knowledge of the future state of a system can be derived from a set of differential equations, relating to the functions defining that system, that provide reasonable estimates of its behavior. This approach, howe v e r, implies first the need to leave aside the individual characteristics o...

There is a widespread agreement that more effective drug delivery vehicles with more alternatives, as well as better active pharmaceutical ingredients (APIs), must be developed to improve the efficacy of microbicide products. For instance, in tropical regions, films are more appropriate than gels due to better stability of drugs at extremes of moisture and temperature. Here, we apply fundamenta...

Ž . Computer-aided molecular design CAMD provides a means for determining molecules or mixtures of Ž . molecules CAMMD having a desirable set of physicochemical properties. The application range of CAMD is restricted due to limitations on the complexity of the generated molecular structures and on the availability of suitable models for property prediction. A new CAMD methodology that addresses...