A highly efficient method for solvent‐free synthesis of bis(arylmethylidene)piperidinones

A remarkably efficient double crossed aldol condensation of piperidin‐4‐one with various aromatic aldehydes is described at room temperature in the presence of diethylamine and lithium perchlorate under solvent‐free conditions. Excellent yields of 3,5‐bis(arylmethylidene)piperidinones are achieved in a facile one‐pot general procedure. Structure of the products is determined by spectroscopic methods and elemental analysis.     

Resolving the coupled effects of hydrodynamics and DLVO forces on colloid attachment in porous media

Transport of colloidal particles in porous media is governed by the rate at which the colloids strike and stick to collector surfaces. Classic filtration theory has considered the influence of system hydrodynamics on determining the rate at which colloids strike collector surfaces, but has neglected the influence of hydrodynamic forces in the calculation of the collision efficiency. Computational simulations based on the sphere-in-cell model were conducted that considered the influence of hydrodynamic and Derjaguin-Landau-Verwey-Overbeek (DLVO) forces on colloid attachment to collectors of various shape and size. Our analysis indicated that hydrodynamic and DLVO forces and collector shape and size significantly influenced the colloid collision efficiency. Colloid attachment was only possible on regions of the collector where the torque from hydrodynamic shear acting on colloids adjacent to collector surfaces was less than the adhesive (DLVO) torque that resists detachment. The fraction of the collector surface area on which attachment was possible increased with solution ionic strength, collector size, and decreasing flow velocity. Simulations demonstrated that quantitative evaluation of colloid transport through porous media will require nontraditional approaches that account for hydrodynamic and DLVO forces as well as collector shape and size.     

Ab initio parametrized MM3 force field for the metal-organic framework MOF-5

A new valence force field has been developed and validated for a particular class of coordination polymers known as nanoporous metal-organic frameworks (MOFs), introduced recently by the group of Yaghi. The experimental, structural, and spectroscopic data in combination with density functional theory calculations on several model systems were used to parametrize the bonded terms of the force field, which explicitly treats the metal-oxygen interactions as partially covalent as well as distinguishes different types of oxygens in the framework. Both the experimental crystal structure of MOF-5 and vibrational infrared spectrum are reproduced reasonably well. The proposed force field is believed to be useful in atomistic simulations of adsorption/diffusion of guest molecules inside the flexible pores of this important class of MOF materials.     

Synthesis,crystal structure,and properties of hybrid-3D copper tetraphosphonate: [Cu3((HO3PCH2)2N–CH2C6H4CH2–N(CH2PO3H)2)(H2O)4] n

The new copper(II) tetraphosphonate, [Cu₃(HO₃PCH₂)₂N–CH₂C₆H₄CH₂–N(CH₂PO₃H)₂)(H₂O)₄] _n (1) was hydrothermally synthesized from the reaction of Cu(NO₃)₂ and (H₂O₃PCH₂)₂N–CH₂C₆H₄CH₂–N(CH₂PO₃H₂)₂, (H₈L). Compound 1 was structurally characterized by means of X-ray single crystal diffraction. The structure of 1 showed a 3D structure constructed from two types of Cu(II) and chelating and bridging modes of (HO₃PCH₂)₂N–CH₂C₆H₄CH₂–N(CH₂PO₃H)₂, and features a (4⁴.6¹⁰.8) topological network. The 3D compound is further stabilized by hydrogen bonds. UV–Vis diffuse reflectance and infrared spectroscopy as well as elemental analysis of compound 1 are also presented.     

Investigation of Rheological Properties of Polyacrylamide/Chromium Triacetate Hydrogels Performed for Water Shutoff Treatment in Oil Reservoirs

In this research, polyacrylamide-based gels were made at 25°C and aged in an oven at 90°C for 24 hours. The bottle testing results indicated that gel composed of 15000 ppm partially hydrolyzed polyacrylamide (PHPA) and 2500 ppm chromium(III) acetate exhibited an acceptable strength. The strain sweep test results showed that elastic modulus is fixed on 6 Pa below strain of 100%. According to frequency test results, linear viscoelasticity region was observed at the frequency limits from 0.1 to 10 s^?1. Moreover, elastic modulus decreased from 8 Pa at 25°C to 4 Pa at 90°C. Furthermore, gelation time for gelant with the same composition was obtained (14, 13, and 20 minutes) in sequence.     

Ethanolic extract of Ferula gummosa is cytotoxic against cancer cells by inducing apoptosis and cell cycle arrest

Ferula gummosa Boiss. has medicinal applications in treating a wide range of diseases including cancer. The objective of this study was to evaluate the antiproliferative activities of the seed and gum extracts of F. gummosa as well as to study the effect of the potent extract on the induction of apoptosis and cell cycle arrest. Our results demonstrated that the ethanolic extract had the lowest IC₅₀ value at 72 h (0.001 ± 1.2 mg/mL) in BHY cells. Moreover, flowcytometry and annexin-V analysis revealed that the ethanolic extract induced apoptosis and cell-cycle arrest in BHY cells at G1/S phase. In addition, colorimetric methods exhibited the highest amount of total phenolics and flavonoids in the aqueous and gum extracts (0.12 ± 0.037, 0.01 ± 2.51 mg/g of dry powder). Generally, the results obtained indicate that F. gummosa ethanol extract may contain effective compounds which can be used as a chemotherapeutic agent.     

Weak gravity conjecture from conformal field theory: a challenge from hyperscaling violating and Kerr-Newman-AdS black holes

We search for a possible relationship between weak gravity conjecture (WGC) and conformal field theory (CFT) in hyperscaling violating and Kerr-Newman-AdS black holes. We deal with the critical points of the black hole systems using the correlation function introduced in CFT and discuss WGC conditions using the imaginary part of the energy obtained from the critical points and their poles. Under the assumptions \begin{document}$ z=1 $\end{document}, \begin{document}$ d=1 $\end{document}, and \begin{document}$ \theta\rightarrow0^{-} $\end{document}, we link WGC to hyperscaling violating black holes owing to the existence of \begin{document}$ r_{H} $\end{document} values larger and smaller than one. For the second black hole system, we study the conditions of WGC for Kerr-Newman-AdS black holes using rotation and radius parameters. Then, we show that the conditions of WGC are satisfied when the charged particle near the hyperscaling violating and Kerr-Newman black holes is \begin{document}$ \frac{1}{a} $\end{document} with a ratio \begin{document}$ \frac{a}{\ell}\ll 1 $\end{document}.     

Simple design of an aligned transparent biofilm by magnetic particles and its cellular study

The aim of this study was to produce aligned biodegradable films. In this study, we used magnetic microparticles and strong magnetic field for orientation of gelatin gels. The samples were evaluated by microscopic analyses and cell culture assays with Schwann cells. Results of structural analyses showed a good arrangement and orientation of films under strong magnetic field with movement of magnetite particles. Cellular experiments showed a good cell adhesion and orientation on the designed films compared with those on unmodified ones. This aligned guide appears to have the right organization for testing in vivo nerve tissue engineering studies. Copyright © 2016 John Wiley & Sons, Ltd.