AlCl3 as a powerful catalyst for the one-pot preparation of 1,1,3-triheteroaryl compounds

A general and efficient procedure for the synthesis of 1,1,3-triheteroaryl compounds in good to excellent yield at room temperature is developed. The reaction proceeds via mixed Michael and Friedel-Crafts reactions of α,β-enals or α,β-enones and indoles, 2-methylfuran or 2-methylthiophene in the presence of a catalytic amount of AlCl₃.     

Tungstate Sulfuric Acid: A Novel and Efficient Solid Acidic Reagent for the Oxidation of Thiols to Disulfides and the Oxidative Demasking of 1,3-Dithianes

Tungstate sulfuric acid in combination with various oxidants was found to be an efficient reagent for the conversion of thiols to disulfides at r.t. in good to excellent yields. The selective oxidative deprotection of 1,3-dithianes to their parent carbonyl compounds at r.t. was also observed with this reagent.     

Si-decorated graphene: a superior media for lithium-ions storage

The characteristics of lithium adsorption on Si-decorated graphene are investigated using first-principles density functional theory calculations. It is found that the Si atom is strongly adsorbed at the bridge site of the C–C bond with binding energy of about ?26.75 kcal/mol. We show that Si decorating turns Si:graphene complex into an electron-deficient system and significantly enhances the Li-storage capacity on the graphene. The obtained results indicate that up to eight Li-ions being adsorbed onto the Si-decorated graphene can form the stable complex. It is found, interestingly, that two Si atoms coated onto double-side of the graphene can strongly adsorb sixteen Li-ions. The analyses of electronic structures show a strong interaction between Li-ions and Si-decorated graphene leading to a high exothermicity. The stability of the sixteen Li-ions adsorbed on the Si:graphene system was evaluated with ab initio molecular dynamics simulation which have been carried out at room temperature. Our first-principles results are relevant to identify the potential applications of Si-decorated graphene as superior media for Li-ions storage.     

Approximate amenability of certain inverse semigroup algebras

In this article, the approximate amenability of semigroup algebra ?¹(S) is investigated, where (S) is a uniformly locally finite inverse semigroup. Indeed, we show that for a uniformly locally finite inverse semigroup (S), the notions of amenability, approximate amenability and bounded approximate amenability of ?¹(S) are equivalent. We use this to give a direct proof of the approximate amenability of ?¹(S) for a Brandt semigroup (S). Moreover, we characterize the approximate amenability of ?¹(S), where S is a uniformly locally finite band semigroup.     

Temporo-insular enhancement of EEG low and high frequencies in patients with chronic tinnitus. QEEG study of chronic tinnitus patients

Background  

The physiopathological mechanism underlying the tinnitus phenomenon is still the subject of an ongoing debate. Since oscillatory EEG activity is increasingly recognized as a fundamental hallmark of cortical integrative functions, this study investigates deviations from the norm of different resting EEG parameters in patients suffering from chronic tinnitus.     

Erratum to “A new branch and bound method with pretreatment for the binary quadratic programming” [Appl. Math. Comput. 192 (2007) 252-259]

We present in this note, an Erratum in “A new branch and bound method with pretreatment for the binary quadratic programming” by Xuewen Mu et al.