Logistic kinetic model for dichlorinated polyaromatic hydrocarbons (PAHs) activity in cancer signaling

The logistic kinetics model of quantitative structure-activity relationships was here implemented for modeling the depletion of the CIPAHs in MCF-7 cells; it was found that the best statistical performances are given by polarizability, electronegativity and hydrophobicity within density functional framework, through a mono-linear Spectra-SAR analysis

Silica aerogels synthesized with butyl-4-methylpyridinium tetrafluoroborate

The supercritical drying effects were investigated, on a series of samples synthesized with: tetramethoxysilane and methyltrimethoxysilane, used as precursors, and butyl-4- methylpyridinium tetrafluoroborate (BMPyBF4) ionic liquid (IL), as gelation catalyst. These results show that the IL addition has a significant impact on the structure of the aerogel as a function of used nIL/nSi molar ratio

Urea formaldehyde coated with Silica (Nano) capsules synthesis in ultrasonic field

Silica nanomaterials with meso- and macroporosity are of great interest due to their variety of potential applications. These hybrid nanomaterials, including hollow silica nano and micro-particles have attracted more and more attention with potential applications in medicine, environmental protection and analytical chemistry. In this work we present a fast and simple method for of urea-formaldehyde (UF) nanoparticles obtained in basic medium encapsulation by a thin shell coating of silica, thus yielding organic-inorganic hybrid materials. It was employed (U:F): SiC^: mole ratios of (1:1 ):5; (1:1): 10; respectively. The influence of reaction parameters variation as temperature, pH, and time were studied. The morphology and structure of the products were characterized by FTIR spectroscopy, and Scanning Electron Microscopy; SEM. It was put in evidence some of resulted samples characteristics that are correlated to synthesis conditions

Ultrasonic preparation of mesoporous silica using pyridinium ionic liquid

Mesoporous silica matrices have been prepared via classic acid catalyzed and sono-catalyzed sol-gel routes. Tetramethoxysilan (TMOS) and methyl-trimethoxysilane (MTMS) were used as silica precursors, and N-butyl-3-methylpyridinium tetrafluoroborate ([bmPy][BF4]) was employed as co-solvent and pore template. The ionic liquid (IL) to silica mole ratio was varied between 0.007 and 0.07. Nitrogen adsorption-desorption and small-angle neutron scattering measurements were used to characterize the obtained materials. The ionic liquid played the role of catalyst that affected the formation of the primary xerogel particles, and changed the porosity of the materials. Ultrasound treatment resulted in microstructure change on the level of the colloid particle aggregates. In comparison with IL containing xerogels, the IL containing sonogels show increased pore diameter, bigger pore volumes and diminished surface areas

Alert-QSAR. Implications for Electrophilic Theory of Chemical Carcinogenesis

Given the modeling and predictive abilities of quantitative structure activity relationships (QSARs) for genotoxic carcinogens or mutagens that directly affect DNA, the present research investigates structural alert (SA) intermediate-predicted correlations ASA of electrophilic molecular structures with observed carcinogenic potencies in rats (observed activity, A = Log[1/TD50], i.e., ASA=f(X1SA,X2SA,…)). The present method includes calculation of the recently developed residual correlation of the structural alert models, i.e., ARASA=f(A−ASA,X1SA,X2SA,…). We propose a specific electrophilic ligand-receptor mechanism that combines electronegativity with chemical hardness-associated frontier principles, equality of ligand-reagent electronegativities and ligand maximum chemical hardness for highly diverse toxic molecules against specific receptors in rats. The observed carcinogenic activity is influenced by the induced SA-mutagenic intermediate effect, alongside Hansch indices such as hydrophobicity (LogP), polarizability (POL) and total energy (Etot), which account for molecular membrane diffusion, ionic deformation, and stericity, respectively. A possible QSAR mechanistic interpretation of mutagenicity as the first step in genotoxic carcinogenesis development is discussed using the structural alert chemoinformation and in full accordance with the Organization for Economic Co-operation and Development QSAR guidance principles