Dynamics of a rumor‐spreading model with diversity of configurations in scale‐free networks

In this paper, we propose a new rumor‐spreading model, which is a variant of the susceptible–exposed–infectious–removed epidemic model. We consider the influences of the diversity of configurations as a defense strategy to diminish the damage brought by rumor diffusion. The diversity of configuration can be found in different instant messengers or social networks. Moreover, we apply two kinds of the rumor immunization strategies such as random immunization and targeted immunization and show that targeted immunization is better than random immunization for rumor‐spreading control in scale‐free networks. We carry out the systematic analysis of the model and study the local and global stability of rumor‐free equilibrium. In the proposed model, we introduce two new states, namely, hibernator and stifler2, to study dynamical behaviors of the model. The proposed model combines both targeted immunization and diversity of configuration to prevent rumor spreading. By numerical simulations, we indicate that our model is appreciably better than other models in terms of declining the rumor diffusion speed. Furthermore, we investigate many related dynamic properties to make the result more complete. Simulation results show the effect of different parameters on the rumor diffusion in scale‐free networks; meanwhile, numerical simulations confirm the theoretical solution. Copyright © 2015 John Wiley & Sons, Ltd.     

Photochromism and Photoisomerization in Some 2,3,4,4,5,6-Hexasubstituted 4H-Thiopyrans

Photochromism and photoisomerization reactions of some new 2,3,4,4,5,6-hexasubstituted 4H-thiopyrans are described.     

Electrocatalytic Oxidation of Cysteine at a CoSalophen/ n‐(butyl)4SiW12O40 Carbon Paste Electrode

In the present study, a novel mixture consisting of N,N′‐bis(salicylidene)‐1,2‐phenylenediamino cobalt (CoSalophen, CoSal) complex and (n‐butyl)₄SiW₁₂O₄₀ (SiW₁₂), have been used to chemically modify a carbon paste electrode (CPE) for sensitive determination of cysteine (CySH). The electrocatalytic effect of the newly developed modified CPE towards oxidation of CySH was evaluated by comparing cyclic and differential pulse voltammograms in the presence of cysteine at bare, CoSal, SiW₁₂ and CoSal/SiW₁₂ modified CPE. The differential pulse voltammetry method was applied as a sensitive method for quantitative detection of CySH trace amounts, the experimental conditions being optimized in order to evaluate the best analytical parameters of the sensor. Reproducibility and stability studies were also performed and the sensor was applied for the determination of CySH in a pharmaceutical sample and in human blood serum and urine samples.     

Aryl diazonium nanomagnetic sulfate and potassium iodide: an iodination process

A simple and efficient procedure for the synthesis of iodoarenes is developed which involves the sequential diazotization–iodination of aromatic amines with sodium nitrite, nanomagnetic supported sulfonic acid, and potassium iodide under solvent-free conditions at room temperature.     

碱性溶液中电聚酪胺-铜草酸盐纳米复合物修饰铜电极电催化甲醇氧化(英文)

A polytyramine-copper oxalate nanocomposite modified copper(PTCOxNMC) electrode prepared by electropolymerization was examined for electrocatalytic activity towards the oxidation of methanol in alkaline solution using cyclic voltammetry and impedance spectroscopy. The prepared PTCOxNMC electrode showed a significantly high response for adsorbed methanol oxidation. The effects of various parameters such as potential scan rate and methanol concentration on the electrocatalytic oxidation at the surface of the PTCOxNMC electrode were investigated. Spectrometry techniques such as Fourier transform infrared spectroscopy and scanning electron microscopy were used to determine the surface physical characteristics of the modified electrode and revealed that the polytyramine-copper oxalate nanocomposite particles were highly dispersed on the surface of the copper electrode with a narrow size up to 40 nm. The very high current density obtained for the catalytic oxidation may have resulted from the high electrode surface area caused by modification with the poly-tyramine-copper oxalate nanocomposite.     

Synthesis and evaluation of antiproliferative activity of substituted N-(9-oxo-9H-xanthen-4-yl)benzenesulfonamides

Several novel N-(9-oxo-9H-xanthen-4-yl)benzenesulfonamide derivatives were prepared as potential antiproliferative agents. The in vitro antiproliferative activity of the synthesized compounds was investigated against a panel of tumor cell lines including breast cancer cell lines (MDA-MB-231, T-47D) and neuroblastoma cell line (SK-N-MC) using MTT colorimetric assay. Etoposide, a well-known anticancer drug, was used as a positive standard drug. Among synthesized compounds, 4-methoxy-N-(9-oxo-9H-xanthen-4-yl)benzenesulfonamide (5i) showed the highest antiproliferative activity against MDA-MB-231, T-47D, and SK-N-MC cells. Furthermore, pentafluoro derivatives 5a and 6a exhibited higher antiproliferative activity than doxorubicin against human leukemia cell line (CCRF-CEM) and breast adenocarcinoma (MDA-MB-468) cells. Structure–activity relationship studies revealed that xanthone benzenesulfonamide hybrid compounds can be used for the development of new lead anticancer agents.     

Radical of filters in BL‐algebras

In this paper, the notion of the radical of a filter in BL‐algebras is defined and several characterizations of the radical of a filter are given. Also we prove that A/F is an MV‐algebra if and only if D_s(A) ? F. After that we define the notion of semi maximal filter in BL‐algebras and we state and prove some theorems which determine the relationship between this notion and the other types of filters of a BL‐algebra. Moreover, we prove that A/F is a semi simple BL‐algebra if and only if F is a semi maximal filter of A. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim