Anionic Halomolybdate(III) Chemistry. Tetrahydrofuran Loss from [MoX(3)Y(THF)(2)](-) (X, Y = Cl, Br, I), Preparation and Properties of [Mo(3)X(12)](3)(-) (X = Br, I), and Crystal Structure of the Edge-Sharing Trioctahedral [PPh(4)](3)[Mo(3)I(12)

By interaction of MoX(3)(THF)(3) with [Cat]X in THF, the salts [Cat][MoX(4)(THF)(2)] have been synthesized [X = I, Cat = PPh(4), NBu(4), NPr(4), (Ph(3)P)(2)N; X = Br, Cat = NBu(4), PPh(4) (Ph(3)P)(2)N]. Mixed-halide species [MoX(3)Y(THF)(2)](-) (X, Y = Cl, Br, I) have also been generated in solution and investigated by (1)H-NMR. When the tetraiodo, tetrabromo, and mixed bromoiodo salts are dissolved in CH(2)Cl(2), clean loss of all coordinated THF is observed by (1)H-NMR. On the other hand, [MoCl(4)(THF)(2)](-) loses only 1.5 THF/Mo. The salts [Cat](3)[Mo(3)X(12)] (X = Br, I) have been isolated from [Cat][MoX(4)(THF)(2)] or by running the reaction between MoX(3)(THF)(3) and [Cat]X directly in CH(2)Cl(2). The crystal structure of [PPh(4)](3)[Mo(3)I(12)] exhibits a linear face-sharing trioctahedron for the trianion: triclinic, space group P&onemacr;; a = 11.385(2), b = 12.697(3), c = 16.849(2) ?; alpha = 76.65(2), beta = 71.967(12), gamma = 84.56(2) degrees; Z = 1; 431 parameters and 3957 data with I > 2sigma(I). The metal-metal distance is 3.258(2) ?. Structural and magnetic data are consistent with the presence of a metal-metal sigma bond order of (1)/(2) and with the remaining 7 electrons being located in 7 substantially nonbonding orbitals. The ground state of the molecule is predicted to be subject to a Jahn-Teller distortion, which is experimentally apparent from the nature of the thermal ellipsoid of the central Mo atom. The [Mo(3)X(12)](3)(-) ions reacts with phosphines (PMe(3), dppe) to form products of lower nuclearity by rupture of the bridging Mo-X bonds.     

In Vivo Endoscopic Tissue Identification by Rapid Evaporative Ionization Mass Spectrometry (REIMS)

Gastrointestinal cancers are a leading cause of mortality, accounting for 23 % of cancer‐related deaths worldwide. In order to improve outcomes from these cancers, novel tissue characterization methods are needed to facilitate accurate diagnosis. Rapid evaporative ionization mass spectrometry (REIMS) is a technique developed for the in vivo classification of human tissue through mass spectrometric analysis of aerosols released during electrosurgical dissection. This ionization technique was further developed by utilizing surface induced dissociation and was integrated with an endoscopic polypectomy snare to allow in vivo analysis of the gastrointestinal tract. We tested the classification performance of this novel endoscopic REIMS method in vivo. It was shown to be capable of differentiating between healthy layers of the intestinal wall, cancer, and adenomatous polyps based on the REIMS fingerprint of each tissue type in vivo.     

Unexpected regio- and stereoselective [4 + 3] cycloaddition reaction of azomethine ylides with benzylidene thiazolidinediones: synthesis of pharmacologically active spiroindoline oxazepine derivatives and theoretical study

Molecular Diversity - An unexpected regio- and stereoselective [4?+?3] cycloaddition reaction of azomethine ylides with 5-benzylidenethiazolidine-2,4-diones has been successfully...     

Phytochemical fabrication,characterization, and antioxidant application of copper and cobalt oxides nanoparticles using <Emphasis Type="Italic">Sesbania sesban</Emphasis> plant

In this work, an ecofriendly and economic strategy for synthesize of CuO and Co₃O₄ were developed using extracted Sesbania sesban solution (ESS) as a reducing and stabilizing agent, and bioreactor. These novel nano metal oxides (NMOs) were characterized by high-resolution-transmission electron microscopy (TEM), EDAX thermo gravimetric analysis and X-ray diffraction (XRD). Morphology and size of them were investigated by TEM and the average sizes of for spherical CuO and Co₃O₄ nanoparticles are 20–40 and 15–30 nm, respectively. The XRD and EDAX confirmed the high purity for NMOs. The thermal behaviors of the NMOs exhibited good crystallographic stability within the investigated temperature range. The antioxidant and antibacterial activities of NMOs were investigated and compared to manganese(III) meso-tetraphenylporphyrin complex/Ag nanocomposite (Ag/P nanocomposite) synthesizing by ESS. The results obtained from this work showed that copper(II) oxide, cobalt oxide nanoparticles, and Ag/P nanocomposite have DPPH scavenging activity. On the other hand, NMOs have no antibacterial activity against Gram-negative bacterial strains. Cobalt oxide nanoparticles have antibacterial activity against Staphylococcus aureus, while Ag/P nanocomposite showed the antibacterial activities against both Gram-negative and Gram-positive bacterial strains.     

Numerical solution of the time-dependent incompressible Navier-Stokes equations in the stream function and vorticity formulation

In this work we study the time-dependent incompressible Navier-Stokes problem. We introduce a suitable technique based on the splitting of the vorticity into two components. Then we discretize in space the resulting uncoupled system by means of continuous Lagrange finite elements. This is achieved by first performing the semi-discretization in time of these equations by a classical characteristics method for the advective term. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

All-optical logic gates using semiconductor-based three-coupled waveguides nonlinear directional coupler

All-optical logic gates with nonlinear optical (NLO) properties of three-coupled identical waveguides have been proposed and designed theoretically in a unique semiconductor-based symmetric structure. The model uses the NLO interactions of the coupled waveguides, like Kerr effect and Two Photon Absorption (TPA). Unlike the previous studies, we take into account higher order NLO effects of semiconductors such as Free Carriers (FC) and loss to control the switching operation. These NLO phenomena lead to high functionality in a simple unique structure. Therefore, in this work, by setting the input intensity of the waveguides, the logic AND, OR, NAND, and NOR gates are designed in a unique structure with different lengths. Our analysis deals with continuous waves (CW) region and the results are valid for the ranges of short optical pulses with time duration longer than FC life time.     

All-optical flip-flop by nonlinear coupling of microring and waveguide

Careful studies of coupling show that transmittance power between microring and waveguide is dependant to field intensity. Also more researches show that optical multistable behavior of microring had been affected by nonlinear power coupling efficiency in high field intensities. Operation of microring in nonlinear regions can be so useful in designing all optical switches and control techniques. In this paper has been proposed an all-optical flip-flop based on nonlinear treatment of microring.     

Photocatalytic application of BiFeO<Subscript>3</Subscript> synthesized via a facile microwave-assisted solution combustion method

Bismuth ferrite (BiFeO₃) nanopowder have been successfully synthesized for the first time via a microwave-assisted sol-gel combustion method by using citric acid as fuel. The resulting nanopowder was characterized using FT-IR, TG-DTA, XRD, EDX, VSM, SEM, and UV-Vis DRS. A ferromagnetic hysteresis loop with a saturation magnetization (M_S) of 0.66?emu?g^?1 has been observed at room temperature in the sample. The optical properties of the nanosized BiFeO₃ showed its small band gap (=2.08?eV) indicates a possibility of utilizing much visible light for photocatalysis.

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Numerical solution of the time-dependent incompressible Navier–Stokes equations by piecewise linear finite elements

In this paper we present a new method to solve the 2D generalized Stokes problem in terms of the stream function and the vorticity. Such problem results, for instance, from the discretization of the evolutionary Stokes system. The difficulty arising from the lack of the boundary conditions for the vorticity is overcome by means of a suitable technique for uncoupling both variables. In order to apply the above technique to the Navier–Stokes equations we linearize the advective term in the vorticity transport equation as described in the development of the paper. We illustrate the good performance of our approach by means of numerical results, obtained for benchmark driven cavity problem solved with classical piecewise linear finite element.