kobra akhavan

This research presents quantitative structure-activity relationship (QSAR) of half maximal inhibitory concentration (IC50 ) values of 31 different Methotrxate derivatives by employing Multiple linear regression (MLR) and artificial neural networks (ANN), simulated annealing algorithm (SA) and genetic algorithm(GA). Furthermore, CORAL software was used for multiple probability simulation of the studied derivatives. The obtained results from MLR-MLR, MLR-SA, SA-ANN, MLR-GA and GA-ANN approaches were compared and GA-ANN combination showed the best performance according to its correlation coefficient (R2) and mean sum square errors (RMSE). From Monte Carlo simulations, it was found that the presence of double bond, the presence of nitrogen and oxygen, the absence of sulphur and phosphorus and connected sp2 carbon to the ring, are the most important molecular features that affect the biological activity of the drug. It was concluded that the simultaneous application of GA-ANN and Monte Carlo methods can provide a more comprehensive understanding of the relationship between a drug's physicochemical, structural, or theoretical molecular descriptors and its biological activity, leading to accelerate the development of new drugs.

The paper is focused on the formation of calcium phosphate nanoparticles (CP) in polyelectrolyte-modified microemulsions, in a microemulsion template phase consisting of cyclohexane, water, anionic surfactantant and cosurfactant, in the presence of anionic and cationic polyelectrolyte. It is shown that polyelectrolyte, can be incorporated into the individual inverse microemulsion droplets. The microemulsion droplets and polyelectrolyte-filled microemulsion droplets can be successfully used as a template phase for the nanoparticles formation. Prepared CP in the presence of anionic polyelectrolyte has a different morphology from samples which are synthesized in the presence of cationic polyelectrolyte. Cationic polyelectrolyte(poly diallyl dimethyl ammonium chloride PDADMAC) leads to formation of needle-like CP (10-20 nm in diameter and 100-150 nm in length). Formation of CPat room temperature was confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Size and morphology of the CP samples were characterized using transmission electron microscopy (TEM).