In vitro antitumor and antibacterial assay of organotin(IV) complexes of 2,3-methylenedioxybenzoic acid; X-ray crystal structure of [(C2H5)2Sn(C8H5O4)2]

New organotin(IV) compounds containing the carboxylate ligand 2,3-methylenedioxybenzoic acid (HL) have been synthesized with the general formula R₂SnL₂ (R = Me, Et, n-Bu, Ph and n-Oct) and R₃SnL (R = n-Bu). All compounds have been studied in the solution state by multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn) by using the non-coordinating solvent and also in solid sate by FTIR, mass spectrometry and X-ray crystallography. Spectroscopic data have shown that methylenedioxy moiety does not coordinate with tin atom and the coordination site is actually -COO group, as is proved by X-ray structure determination. The solid state structure of compound (2) has been determined by X-ray crystallography which shows that the complex (2) has distorted octahedral geometry. These complexes have been evaluated in vitro against crown gall tumor and antibacterial activity. Interesting results were noticed during the bio-activity screenings, which proved their in vitro biological potential and possible use as drugs.     

Accretion of Phantom Energy and Generalized Second Law of Thermodynamics for Einstein-Maxwell-Gauss-Bonnet Black Hole

We have investigated the accretion of phantom energy onto a 5-dimensional extreme Einstein-Maxwell-Gauss-Bonnet (EMGB) black hole. It is shown that the evolution of the EMGB black hole mass due to phantom energy accretion depends only on the pressure and density of the phantom energy and not on the black hole mass. Further we study the generalized second law of thermodynamics (GSL) at the event horizon and obtain a lower bound on the pressure of the phantom energy.     

Entropy and specific heat as a measure of fluctuations in multiparticle production in relativistic nuclear collisions

An analysis to disentangle information about the occurrence of dynamical fluctuations in multiparticle production in high energy nucleus-nucleus collisions has been carried out in terms of fractal moments and entropy for the experimental and simulated data using FRITIOF, UrQMD and HIJING generators. Although there is a possibility to thermodynamically interpret the final state of multiparticle production by calculating the values of specific heat, c, using G _q - and F _q -moments. However, both these moments give markedly different values of c. The constancy observed in the values of specific heats calculated from either G _q - or F _q -moments is in accord with the predictions of constant specific heat approximation. Variations of multifractal and factorial moments and various other parameters calculated from these moments predict the presence of non-statistical fluctuations in high energy nuclear collisions.     

Hidden itinerant-spin phase in heavily overdoped La(2-x)Sr(x)CuO4 superconductors revealed by dilute Fe doping: a combined neutron scattering and angle-resolved photoemission study

We demonstrated experimentally a direct way to probe a hidden propensity to the formation of a spin-density wave in a nonmagnetic metal with strong Fermi surface nesting. Substituting Fe for a tiny amount of Cu (1%) induced an incommensurate magnetic order below 20 K in heavily overdoped La(2-x)Sr(x)CuO(4). Elastic neutron scattering suggested that this order cannot be ascribed to the localized spins on Cu or doped Fe. Angle-resolved photoemission revealed a strong Fermi surface nesting inherent in the pristine La(2-x)Sr(x)CuO(4) that likely drives this order. Our finding presents the first example of the long-sought "itinerant-spin extreme" of cuprates, where the spins of itinerant doped holes define the magnetic ordering ground state; it complements the current picture of cuprate spin physics that highlights the predominant role of localized spins at lower dopings.     

Living fungal hyphae-templated porous gold microwires using nanoparticles as building blocks

Abstract  

A simple and environmentally benign green method is reported to decorate growing fungal hyphae with high loading of gold nanoparticles, which were initially produced using aqueous tea extract as a sole reducing/stabilizing agent. Inoculation of fungal spores in aqueous suspension of nanoparticles led to the growth of intensely red-coloured fungal hyphae due to the accumulation of gold nanoparticles. Heat treatment of these hybrid materials led to the formation of porous gold microwires. This report is thus an interesting example of using green and sustainable approach to produce nanostructured materials which have potential applications in catalysis, sensing and electronics.     

Cascade-exciton model analysis of level density parameter dependence in proton induced fission cross sections of some sub-actinide nuclei

Fission cross sections strongly depend on the ratio of the level density parameter in fission to neutron emission, a_f/a_n. In this work, a cascade-exciton model implemented in the code CEM95 has been used to observe this effect for proton induced fission cross sections of tungsten, lead and bismuth. The method was employed using different level density parameter ratios for each fission cross section calculation. The calculated fission cross sections are compared with the available experimental data in the literature. It has been observed that a change of the ratio of the level density parameter, a_f/a_n, is necessary with the incident energy of the proton, to best estimate the fission cross sections in CEM95.     

On Some Inequalities Concerning Rate of Growth of Polynomials

In this paper we consider a class of polynomials P(z) = a0+∑n v=t a v z v, t ≥ 1not vanishing in |z|k, k≥1 and investigate the dependence of max|z|=1|P(Rz)-P(rz)on max|z|=1|P(z)|, where 1 ≤ r R. Our result generalizes and refines some know polynomial inequalities.     

EM-Wave Diffraction by a Finite Plate with Dirichlet Conditions in the Ionosphere of Cold Plasma

In the current communication, the problem of plane wave diffraction by a conductible plate of finite length in the presence of cold plasma is investigated. The boundary-value problem corresponding to this model is formulated by Fourier transform which then leads to the Wiener?Hopf equation. The resulting equation has been solved by the Wiener?Hopf procedure in a standard way. The separated field (diffracted field) is analyzed in an anisotropic medium using asymptotic expansion and modified stationary phase method. The problem can be made simple by assuming ε₂→0, where ε₂ is the element of permittivity tensor. This happens, if the operating frequency is assumed to be very large as compared to ω_c (cyclotron frequency) while it is of same order of ω_p (the plasma frequency). The case ε₁ =1, ε₂→0 leads to the results for soft plate of finite length in an isotropic medium. Graphical study is performed to investigate the behavior of separated field for various physical parameters for isotropic and anisotropic media.     

A divergent approach to highly substituted benzothiepinones and to 2,3-dihydrothieno[2,3-b]thiopyran-4-ones

The radical addition-transfer of S-(2-fluoro-phenacyl)xanthates can be used to construct rapidly benzothiepinones, including libraries of complex aza-bridged derivatives, and highly functionalized 2,3-dihydrothieno[2,3-b]thiopyran-4-ones.