Tensile modulus of polymer/CNT nanocomposites by effective volume fraction of nanoparticles as a function of CNT properties in the network

In this article, the effects of filler network and interphase between polymer matrix and nanoparticles on the tensile modulus of polymer/carbon nanotubes (CNT) nanocomposites are assumed by the effective volume fraction of nanoparticles. By this approach, the Takayanagi model is developed for polymer/CNT nanocomposites above percolation threshold. Also, the effective factors for filler network including the number (N ), aspect ratio (α ) and percolation threshold (? _p ) of CNT are correlated to three main parameters. The developed model is evaluated for some reported samples from previous papers, and the influences of main parameters on the modulus are examined. The acceptable predictability of the developed model for modulus of nanocomposites is illustrated by experimental results. The “α ” and “N ” parameters play positive roles in the modulus, while an inverse relation is observed between the modulus and the percolation threshold. The reasonable effects of these parameters on the tensile modulus of polymer/CNT nanocomposites are also discussed. Copyright © 2017 John Wiley & Sons, Ltd.     

Synthesis of a fluorous ligand and its application for asymmetric addition of dimethylzinc to aldehydes

A new fluorous ligand was synthesized from the acetonide of dimethyl tartarate, which showed excellent asymmetric induction on the addition of dimethylzinc to aldehydes. This ligand will be useful for synthesis of bioactive compounds with a methyl carbinol moiety. It could be recycled without using a fluorous solvent or a fluorous column.     

Application of derivative, derivative ratio, and multivariate spectral analysis and thin-layer chomatography-densitometry for determination of a ternary mixture containing drotaverine hydrochloride, caffeine, and paracetamol

New selective, precise, and accurate methods are described for the determination of a ternary mixture containing drotaverine hydrochloride (I), caffeine (II), and paracetamol (III). The first method uses the first (D1) and third (D3) derivative spectrophotometry at 331 and 315 nm for the determination of (I) and (III), respectively, without interference from (II). The second method depends on the simultaneous use of the first derivative of the ratio spectra (DD1) with measurement at 312.4 nm for determination of (I) using the spectrum of 40 microg/mL (III) as a divisor or measurement at 286.4 and 304 nm after using the spectrum of 4 microg/mL (I) as a divisor for the determination of (II) and (III), respectively. In the third method, the predictive abilities of the classical least-squares, principal component regression, and partial least-squares were examined for the simultaneous determination of the ternary mixture. The last method depends on thin-layer chromatography-densitometry after separation of the mixture on silica gel plates using ethyl acetate-chloroform-methanol (16 + 3 + 1, v/v/v) as the mobile phase. The spots were scanned at 281, 272, and 248 nm for the determination of (I), (II), and (III), respectively. Regression analysis showed good correlation in the selected ranges with excellent percentage recoveries. The chemical variables affecting the analytical performance of the methodology were studied and optimized. The methods showed no significant interferences from excipients. Intraday and interday assay precision and accuracy values were within regulatory limits. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of their pharmaceutical preparations. The validity of the proposed methods was further assessed by applying a standard addition technique. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.     

Electro-Optic Switching in a Double Quantum Dot Injected with a Squeezed Vacuum Field

Journal of Russian Laser Research - Optical bistability (OB) is theoretically examined for a double quantum dot (QD) system placed in a ring cavity that is injected with a squeezed vacuum (SV)...     

Proximate Composition,Bioactive Compounds,and Antioxidant Potential of Wild Halophytes Grown in Coastal Salt Marsh Habitats

Halophytes have been characterized as a potential resource for fiber, food, fodder, and bioactive compounds. Proximate composition, bioactive compounds, and antioxidant activity of five wild dominant halophytes (Arthrocnemum macrostachyum, Halocnemum strobilaceum, Limoniastrum monopetalum, Limoniastrum pruinosum, and Tamarix nilotica) naturally growing along the Nile Delta coast were assessed. The soil supporting these halophytes was sandy to sand-silty, alkaline, with low organic carbon, and relatively high CaCO₃. H. strobilaceum attained the highest moisture content, ash, crude fiber, lipids, and total soluble sugars. L. monopetalum showed the highest content of crude protein (18.00%), while T. nilotica had the highest content of total carbohydrates. The studied halophytes can be ranked according to their nutritive value as follows: H. strobilaceum > L. monopetalum > A. macrostachyum > L. pruinosum > T. nilotica. A. macrostachyum attained the highest amount of Na⁺, K⁺, Ca²⁺, and Mg²⁺. A. macrostachyum showed a high content of phenolic compounds, while H. strobilaceum was rich in tannins and saponin contents. The MeOH extract of A. macrostachyum and H. strobilaceum exhibited substantial antioxidant activity. The present results showed that the studied halophytes could be considered as candidates for forage production or used as green eco-friendly natural resources for bioactive compounds.     

Investigation of the Anticancer Effect of α-Aminophosphonates and Arylidine Derivatives of 3-Acetyl-1-aminoquinolin-2(1H)-one on the DMBA Model of Breast Cancer in Albino Rats with In Silico Prediction of Their Thymidylate Synthase Inhibitory Effect

Breast cancer is a major cause of death in women worldwide. In this study, 60 female rats were classified into 6 groups; negative control, α-aminophosphonates, arylidine derivatives of 3-acetyl-1-aminoquinolin-2(1H)-one, DMBA, DMBA & α-aminophosphonates, and DMBA & arylidine derivatives of 3-acetyl-1-aminoquinolin-2(1H)-one. New α-aminophosphonates and arylidine derivatives of 3-acetyl-1-aminoquinolin-2(1H)-one were synthesized and elucidated by different spectroscopic and elemental analysis. Histopathological examination showed marked proliferation of cancer cells in the DMBA group. Treatment with α-aminophosphonates mainly decreased tumor mass. Bcl2 expression increased in DMBA-administered rats and then declined in the treated groups, mostly with α-aminophosphonates. The level of CA15-3 markedly declined in DMBA groups treated with α-aminophosphonates and arylidine derivatives of 3-acetyl-1-aminoquinolin-2(1H)-one. Gene expression of GST-P, PCNA, PDK, and PIK3CA decreased in the DMBA group treated with α-aminophosphonates and arylidine derivatives of 3-acetyl-1-aminoquinolin-2(1H)-one, whereas PIK3R1 and BAX increased in the DMBA group treated with α-aminophosphonates and arylidine derivatives of 3-acetyl-1-aminoquinolin-2(1H)-one. The molecular docking postulated that the investigated compounds can inhibt the Thymidylate synthase TM due to high hydrophobicity charachter.     

Anti‐tumor platinum (IV) complexes bearing the anti‐inflammatory drug naproxen in the axial position

The role of inflammation in cancer generation is gaining importance in the field of cancer research. The chemo‐anti‐inflammatory strategy that involves using non‐steroidal anti‐inflammatory drug compounds as effective anti‐tumor agents is being acceded globally. In the present study, seven new Pt (IV) complexes based on cisplatin, carboplatin and oxaliplatin scaffold bearing the anti‐inflammatory drug naproxen in the axial position were synthesized and characterized by elemental analysis, ESI‐MS, Fourier transform‐infrared, ¹H‐ and ¹⁹⁵Pt‐NMR spectroscopy. The reduction behavior in the presence of ascorbic acid was studied using high‐performance liquid chromatography. The cytotoxicity against two human breast cell lines and the anti‐inflammatory properties were evaluated. All the complexes are able to promote a comparable activity, with average three‐ and 13‐fold more cytotoxic than cisplatin against MCF7 and MDA‐MB‐231 cell lines, respectively. The complexes show remarkable anti‐inflammatory effects, which indicated their potential in treating cancer associated with inflammation and reducing side‐effects of chemotherapy.     

A Chaotic-Based Encryption/Decryption Framework for Secure Multimedia Communications

Chaos-based encryption has shown an increasingly important and dominant role in modern multimedia cryptography compared with traditional algorithms. This work proposes novel chaotic-based multimedia encryption schemes utilizing 2D alteration models for high secure data transmission. A novel perturbation-based data encryption for both confusion and diffusion rounds is proposed. Our chaotification structure is hybrid, in which multiple maps are combined combines for media encryption. Blended chaotic maps are used to generate the control parameters for the permutation (shuffling) and diffusion (substitution) structures. The proposed schemes not only maintain great encryption quality reproduced by chaotic, but also possess other advantages, including key sensitivity and low residual clarity. Extensive security and differential analyses documented that the proposed schemes are efficient for secure multimedia transmission as well as the encrypted media possesses resistance to attacks. Additionally, statistical evaluations using well-known metrics for specific media types, show that proposed encryption schemes can acquire low residual intelligibility with excessive nice recovered statistics. Finally, the advantages of the proposed schemes have been highlighted by comparing it against different state-of-the-art algorithms from literature. The comparative performance results documented that our schemes are extra efficacious than their data-specific counterpart methods.     

Role of hybrid nanostructures and dust particles on transport of heat energy in micropolar fluid with memory effects

Journal of Thermal Analysis and Calorimetry - Constitutive models exhibiting viscoelastic and micro-inertia with vortex viscosity effects are used for modeling of transport of heat energy, (angular...     

Detection of adulteration in acetonitrile

To address the increasing concern that acetonitrile may be intentionally adulterated to meet the shortfall in global supplies resulting from a downturn in its manufacturing, three analytical techniques were examined in this study. Gas Chromatography with Thermal Conductivity Detection (GC-TCD), Near Infrared (NIR) spectroscopy and Fourier Transform Infrared (FT-IR) spectroscopy were assessed for their ability to detect and quantify potential adulterants including water, alternative organic solvents, and by-products associated with the production of acetonitrile. The results of the assessment of the three techniques for acetonitrile adulteration testing are discussed.