Multitask Quantum Study of the Curcumin-Based Complex Physicochemical and Biological Properties

Density functional theory (DFT), time-dependent density functional theory (TDDFT), quantum theory of atoms in molecules (QTAIM), and extended transition state natural orbitals for chemical valence (ETS-NOCV) have all been used to investigate the physicochemical and biological properties of curcumin and three complexes, i.e., Cur-M (M = Ni, Cu, and Mg). Based on DFT calculations, the enolic form (Cur-Enol) is more stable than the anti-diketone form (Cur-Anti diketone) favored for complexation. This enolic form stability was explained by the presence of three intramolecular hydrogen bonds according to the QTAIM analysis. Furthermore, the ETS-NOCV technique revealed that the enolic form had more significant antioxidant activity compared with the anti-diketone form. The calculations from the COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) showed that the dimethyl sulfoxide (DMSO) solvent could dissolve all the curcumin tautomers Cur-Enol, Cur-Anti-diketone and Cur-Cu, Cur-Mg, and Cur-Ni complexes in contrast to benzene, acetone, octanol, ethanol, methanol, and water. Furthermore, except for Cur-Mg, which had a relatively low solubility (14 g/L), all complexes were insoluble in water. Cur-Anti-diketone was considerably more soluble than Cur-Enol in the examined solvents.     

A generalized CAD model for the full‐wave modeling of Coplanar striplines discontinuities

In this work, the coplanar stripline (CPS) and its discontinuities: open‐end, short‐end, gaps and resonator have been modeled. New integral equations for the electrical field components are formulated, in the spectral domain, using an exact dyadic Green's function, applied to the CPS structure. The use of this form of Green's function allows the consideration of the effects of the dielectric losses, the surface wave excitation and the space wave radiation on the propagation characteristics of the CPS and its discontinuities. The resulting integral equation has been solved using the two‐dimensional Galerkin's technique. The resolution of the resulting matrix equation gives the scattering parameters of the studied structures. The obtained results are commented and compared with those of other approaches and measurements. Copyright © 2011 John Wiley & Sons, Ltd.     

Numerical solution of high-order linear Volterra integro-differential equations by using Taylor collocation method

The main purpose of this work is to provide a new direct numerical method for high-order linear Volterra integro-differential equations (VIDEs). An algorithm based on the use of Taylor polynomials is developed for the numerical solution of high-order linear VIDEs. It is shown that this algorithm is convergent. Numerical results are presented and comparisons are made with well-known numerical methods to prove the effectiveness of the presented algorithm.     

Skeletal Optimization of Cytotoxic Lipidic Dialkynylcarbinols

In line with a recent study of the pharmacological potential of bioinspired synthetic acetylenic lipids, after identification of the terminal dialkynylcarbinol (DAC) and butadiynyl alkynylcarbinol (BAC) moieties as functional antitumor pharmacophoric units, this work specifically addresses the issue of carbon backbone length. A systematic variation of the aliphatic chain length was thus carried out in both the DAC and BAC series. The critical impact of the length of the lipidic skeleton was first confirmed in the racemic series, with the highest cytotoxic activity observed for C₁₇ to C₁₈ backbones. Enantiomerically enriched samples were prepared by asymmetric synthesis of the optimal C₁₈ DAC and C₁₇ BAC derivatives. Samples with upgraded enantiomeric purity were alternatively produced by enzymatic kinetic resolution. Eutomers possessing the S configuration displayed cytotoxicity IC₅₀ values as low as 15 nm against HCT116 cancer cells, the highest level of activity reached to date in this series.     

Evaluation using online support-vector-machines and fuzzy reasoning. Application to condition monitoring of speeds rolling process

A method for process condition monitoring and evaluation, which combines the online support vector machine (SVM) regression and the fuzzy sets methods, is proposed. To account for the time dependence, the proposed approach is based on moving windows in order to take into account the past and new data for the model’s adaptation. The fuzzy analysis is then applied to the generated residual data to give an evaluation of the condition monitoring. The proposed approach is applied to hot rolling for constructing a complementary condition monitoring system, which permits an online quality evaluation in the rolling process. Simulation results based on residual data show that the new approach is easily implementable.