The solvent‐free synthesis of polysubstituted pyrroles by a reusable copper Schiff base complex immobilized on silica coated Fe3O4, and DNA binding study of one resulting derivative as a potential anticancer drug

We demonstrate herein the synthesis of a new copper Schiff base complex immobilized on silica‐coated Fe₃O₄ nanoparticles. The structure and composition of this magnetic nanocatalyst were analyzed using Fourier transform infrared (FT‐IR), X‐ray powder diffraction (XRD), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), energy dispersive X‐ray (EDX) and inductively coupled plasma atomic emission spectroscopy (ICP‐AES). This nanocomposite was found to be an efficient nanocatalyst for the synthesis of polysubstituted pyrrole derivatives and the products were isolated with high turnover number (TON) and high to excellent yields. Among the new synthesized polysubstituted pyrrole derivatives, we explored the first computational and experimental binding study of methyl 1‐benzyl‐4‐(furan‐2‐yl)‐2‐methyl‐1H‐pyrrole‐3‐carboxylate (SP‐10) with calf thymus deoxyribonucleic acid (ct‐DNA), suggesting their application as potential anticancer activity. In addition, the binding modes of SP‐10 with DNA and human serum albumin (HSA) were verified by molecular docking technique.     

Active methods to control periodic acoustic disturbances invoking Q-learning techniques

This paper presents a new solution to the Active Noise Control problem based on the Q-learning algorithm. Unlike other common methods, this feedback method does not require any additional information about the primary and secondary transfer functions and it is fully robust to subsystems dynamics changes. The basic method is addressed for periodic acoustic disturbances at first. A number of challenges such as the need for the large memory block and long convergence time have led to the establishment of some new suggestions. These modifications have improved the system performances and decreased the computational burden. It is shown by simulation that these methods are robust not for in the subsystems dynamics changes but also at the presence of measurement noise.     

Synthesis of polysubstituted pyridines via reactions of chalcones and malononitrile in alcohols using Amberlite IRA-400 (OH)

Polysubstituted pyridine derivatives were synthesized through economical one-pot multicomponent reactions of different α,β-unsaturated ketones, malononitrile, and ethanol or methanol in the presence of Amberlite IRA-400 (OH⁻) at room temperature. The catalyst is recyclable several times without substantial loss of activity. Other valuable features include the wide range of functional group tolerance, easy and clean synthesis with a simple work-up procedure, and excellent yields under mild conditions.     

Sizing optimization of truss structures by method of centers and force formulation

This paper describes a new approach to optimum weight design of truss structures. The force method is incorporated in an optimization algorithm based on the method of center points. Design variables are the member cross-sectional areas and the redundant forces evaluated for each independent loading condition acting on the structure. The optimization method utilizes the largest hyperspheres inscribed within the feasible space. The method of hyperspheres has been enhanced here to handle the compatibility equality constraints as well. By including the analysis step in the optimization cycle there is no longer the need to perform separate structural analyses thus saving computation time. The viability and efficiency of the proposed method are demonstrated for truss structures subject to multiple loading conditions and constraints on member stresses, nodal displacement and minimum gage. Numerical results are compared with those reported in the literature.     

Synthesis of Oximes with NH2OH.HCl/DOWEX(R)50WX4 System

The oximation of a variety of carbonyl compounds was efficiently carried out with DOWEX(R)50WX4/NH₂OH·HCl system. The reactions were performed in ethanol to give Z‐aldoximation isomers of aldehydes and E‐oximaton of acetophenone derivatives in a perfect selectively. The oximation of compounds with two carbonyl groups was carried out selectively on one carbonyl moiety. Also, the oximation of aldehydes over ketones has been accomplished successfully by this system.     

Salt-assisted liquid-liquid microextraction of Cr(VI) ion using an ionic liquid for preconcentration prior to its determination by flame atomic absorption spectrometry

We report on the salt-assisted liquid-liquid microextraction of cationic complexes of Cr(VI) ion using the hydrophilic ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoraborate and potassium hydrogen phosphate. This is a novel, simple, non-toxic and effective technique for sample pretreatment technique that displays large extraction efficiency and represents a new platform where Cr(VI) is complexed with 1,5-diphenylcarbazide (DPC) in sulfuric acid medium. It was applied to the extraction of Cr(VI) in the form of the Cr(VI)-DPC complex prior to its determination by flame atomic absorption spectrometry. Cr(III) ion also can be determined by this procedure after oxidation to Cr(VI). Extraction is mainly affected by the amount of water-soluble IL, the kind and quantity of inorganic salts, by pH and the concentration of DPC. Calibration plots are linear in the range from 3 to 150?μg?L^?1 of Cr(VI), and the limit of detection is 1.25?μg?L^?1. The method was successfully applied to the speciation and determination of trace levels of Cr(III) and Cr(VI) in environmental water samples containing high levels of dissolved salts or food grade salts.

Groups with the same orders of maximal abelian subgroups as A_2(q)

In Li and Chen (Sib. Math. J. 53(2), 243–247, 2012), it is proved that the simple group $A_1(p^n)$ is uniquely determined by the set of orders of its maximal abelian subgroups. Let $q=p^{\alpha }$ be a prime power and $L=A_2(q)$ . In this paper, we prove that if $q$ is not a Mersenne prime, then every finite group with the same orders of maximal abelian subgroups as $L$ , is isomorphic to $L$ or an extension of $L$ by a subgroup of the outer automorphism group of $L$ .     

Wet 2,4,6-trichloro-1,3,5-triazine(TCT)as an efficient catalyst for the synthesis of 2,4,6-triarylpyridines under solvent-free conditions

<正>An efficient one-pot synthesis of 2,4,6-triarylpyridines has been described.This involves the three-component reaction of aldehydes,ketones and ammonium acetate in the presence of a catalytic amount of wet 2,4,6-trichloro-1,3,5-triazine(TCT) under solvent-free condition at 130℃.     

H/D exchange kinetics: Experimental evidence for formation of different b fragment ion conformers/isomers during the gas-phase peptide sequencing

Electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) combined with H/D exchange reactions was utilized to explore the existence of different b₅⁺ and b₄⁺ fragment ion conformers/isomers of hexapeptide WHWLQL in the gas phase. Distinct H/D exchange trends for protonated WHWLQL ([M + H]⁺) and its b₅⁺ and b₄⁺ fragment ions (with ND₃) were observed. Isolated ¹²C_all isotopomers of both b₅⁺ and b₄⁺ fragment ions yielded bimodal distributions of H/D exchanged product ions. The H/D exchange reaction kinetics also confirmed that b₅⁺ and b₄⁺ fragment ions exist as combination of slow-exchanging (“s”) and fast-exchanging (“f”) species. The calculated rate constant for the first labile hydrogen exchange of [M + H]⁺ (k_{[M + H]} ⁺ = 3.80 ± 0.7 × 10⁻¹⁰ cm³ mol⁻¹ s⁻¹) was ∼30 and ∼5 times greater than those for the “s” and “f” species of b₅⁺, respectively. Data from H/D exchange of isolated “s” species at longer ND₃ reaction times confirmed the existence of different conformers or isomers for b₅⁺ fragment ions. The sustained off-resonance irradiation collision-activated dissociation (SORI-CAD) of WHWLQL combined with the H/D exchange reactions indicate that “s” and “f” species of b₅⁺ and b₄⁺ fragment ions can be produced in the ICR cell as well as the ESI source. The significance of these observations for detailed understanding of protein sequencing and ion fragmentation pathways is discussed.     

On <Emphasis Type="Italic">r</Emphasis>-recognition by prime graph of <Emphasis Type="Italic">B</Emphasis><Subscript><Emphasis Type="Italic">p</Emphasis></Subscript>(3) where <Emphasis Type="Italic">p</Emphasis> is an odd prime

Let G be a finite group. The prime graph Γ(G) of G is defined as follows. The vertices of Γ(G) are the primes dividing the order of G and two distinct vertices p and p′ are joined by an edge if there is an element in G of order pp′. We denote by k(Γ(G)) the number of isomorphism classes of finite groups H satisfying Γ(G) = Γ(H). Given a natural number r, a finite group G is called r-recognizable by prime graph if k(Γ(G)) =  r. In Shen et al. (Sib. Math. J. 51(2):244–254, 2010), it is proved that if p is an odd prime, then B _p (3) is recognizable by element orders. In this paper as the main result, we show that if G is a finite group such that Γ(G) = Γ(B _p (3)), where p > 3 is an odd prime, then \({G\cong B_p(3)}\) or C _p (3). Also if Γ(G) = Γ(B ₃(3)), then \({G\cong B_3(3), C_3(3), D_4(3)}\), or \({G/O_2(G)\cong {\rm Aut}(^2B_2(8))}\). As a corollary, the main result of the above paper is obtained.