Fourier Transform Infrared Spectroscopic Investigation of the Binary and Ternary Cyanide Adducts of the Oxidized Horseradish Peroxidase: Identification of a Second Stretching Mode for the Carbon-Nitrogen Bond of the Bound Cyanide Ion

The binary and ternary cyanide adducts of the ferric horseradish peroxidase were investigated by Fourier transform infrared spectroscopy. The carbon-nitrogen bond of the bound cyanide ion in the binary ferric cyanohorseradish peroxidase exhibits two stretching vibrations at 2130 cm^?1 and 2127 cm^?1 with the latter mode being observed in this work for the first time. This finding supports the results of the resonance Raman study of cyanohorseradish peroxidase, which identified two iron-carbon-nitrogen bending vibrations and two iron-carbon stretching vibrations, proving the existence of two conformational states. The identification of the latter carbon-nitrogen stretching frequency allowed the assignment of all of the vibrational modes of the iron-carbon-nitrogen groups of the two conformational states of the ferric cyanohorseradish peroxidase. The first conformer is characterized by a carbon-nitrogen stretch at 2130 cm^?1, an iron-carbon stretch at 453 cm^?1, and an iron-carbon-nitrogen bending mode at 405 cm^?1. The second state has a carbon-nitrogen stretch at 2127 cm^?1, an iron-carbon stretch at 360 cm^?1, and an iron-carbon-nitrogen bending mode at 422 cm^?1. The iron-carbon stretching band is weakly sensitive to pH changes, but it is sensitive to H₂O/D₂O substitution, indicating that the bound cyanide ion in cyanohorseradish peroxidase is hydrogen bonded to the surrounding protein. The two states were attributed to variation in the extent of hydrogen bonding of the iron-carbon-nitrogen groups in the two states. The carbon-nitrogen stretching vibrations of the ternary complexes of cyanohorseradish peroxidase with ferulic acid, benzamide, and benzhydroxamic acid have been investigated for the first time. The binding of the substrate to cyanohorseradish peroxidase does not always lead to the vanishing of one of the conformational states as in the carbon monoxide adducts of the ferrous horseradish peroxidase, but can cause shifts in the νC-N frequency and in the relative population of both conformational states.     

Interacting entropy-corrected new agegraphic dark energy in Brans–Dicke cosmology

Motivated by a recent work of one of us (Sheykhi in Phys Rev D 81: 023525, 2010), we extend it by using quantum (or entropy) corrected new agegraphic dark energy in the Brans–Dicke cosmology. The correction terms are motivated from the loop quantum gravity which is one of the competitive theories of quantum gravity. Taking the non-flat background spacetime along with the conformal age of the universe as the length scale, we derive the dynamical equation of state of dark energy and the deceleration parameter. An important consequence of this study is the phantom divide scenario with entropy-corrected new agegraphic dark energy. Moreover, we assume a system of dark matter, radiation and dark energy, while the later interacts only with dark matter. We obtain some essential expressions related with dark energy dynamics. The cosmic coincidence problem is also resolved in our model.     

Power-Law entropy corrected holographic dark energy model

Among various scenarios to explain the acceleration of the universe expansion, the holographic dark energy (HDE) model has got a lot of enthusiasm recently. In the derivation of holographic energy density, the area relation of the black hole entropy plays a crucial role. Indeed, the power-law corrections to entropy appear in dealing with the entanglement of quantum fields in and out the horizon. Inspired by the power-law corrected entropy, we propose the so-called “power-law entropy-corrected holographic dark energy” (PLECHDE) in this Letter. We investigate the cosmological implications of this model and calculate some relevant cosmological parameters and their evolution. We also briefly study the so-called “power-law entropy-corrected agegraphic dark energy” (PLECADE).     

Cardy-Verlinde Formula for an Axially Symmetric Dilaton-axion Black Hole

It is shown that the Bekenstein-Hawking entropy of an axially symmetric dilaton-axion black hole can be expressed as a Cardy-Verlinde formula. By utilizing first order correction in the Bekenstein-Hawking entropy we find the modified the expressions for the Casimir energy and pure extensive energy. The first order correction to the Cardy-Verlinde formula in the context of dilaton-axion black hole are obtained with the use of modified cosmic and pure extensive energies.     

Mesoporous titania photocatalyst: effect of relative humidity and aging on the preparation of mesoporous titania and on its photocatalytic activity performance

Mesoporous TiO₂ has been synthesized by the sol–gel method, using a nonionic triblock copolymer P123 as surfactant template under acidic conditions. The as-prepared samples were characterized by thermogravimetry–differential thermal analysis (TG–DTA), nitrogen absorption–desorption (BET), field emission scanning electron microscopy, and transmission electron microscopy. The photocatalytic activity of the mesoporous TiO₂ was evaluated by degradation of methylene blue under high-intensity UV light irradiation; the amount of methylene blue was measured by UV–visible spectroscopy. TG–DTA analysis revealed that the surfactant had been removed partly in as-synthesized samples. BET analysis proved that all the samples retained mesoporosity with a narrow pore-size distribution (4.5–6.3 nm) and high surface area (103–200 m²/g). All calcined mesoporous TiO₂ had high photocatalytic activity in the photodegradation of methylene blue.     

Notes on dark energy interacting with dark matter and unparticle in loop quantum cosmology

We investigate the behavior of dark energy interacting with dark matter and unparticle in the framework of loop quantum cosmology. In four toy models, we study the interaction between the cosmic components by choosing different coupling functions representing the interaction. We found that there are only two attractor solutions namely dark energy dominated and dark matter dominated Universe. The other two models are unstable, as they predict either a dark energy filled Universe or one completely devoid of it.     

The influence of annealing temperature on the structure,morphologies and optical properties of ZnO nanoparticles

ZnO nanoparticles (NPs) have been successfully synthesized by the simple solution method at low temperature. The effects of annealing temperature on the structure and optical properties of ZnO NPs were investigated in detail by X-ray diffraction, transmission electron microscopy (TEM), ultraviolet–visible (UV–vis) spectroscopy and photoluminescence (PL) measurements. As the annealing temperature was increased above 180 ^°C the particles morphology evolved from spherical to hexagonal shape, indicating that the average particle size increased from 11 nm to 87 nm. The UV-vis and PL spectra showed a red-shift from 3.62 to 3.33 eV when the annealing temperature was increased.     

Fabrication and Evaluation of Voriconazole Loaded Transethosomal Gel for Enhanced Antifungal and Antileishmanial Activity

Voriconazole (VRC) is a broad-spectrum antifungal agent belonging to BCS class II (biopharmaceutical classification system). Despite many efforts to enhance its solubility, this primary issue still remains challenging for formulation scientists. Transethosomes (TELs) are one of the potential innovative nano-carriers for improving the solubility and permeation of poorly soluble and permeable drugs. We herein report voriconazole-loaded transethosomes (VRCT) fabricated by the cold method and followed by their incorporation into carbopol 940 as a gel. The prepared VRCT were evaluated for % yield, % entrapment efficiency (EE), surface morphology, possible chemical interaction, particle size, zeta potential, and polydispersity index (PDI). The optimized formulation had a particle size of 228.2 nm, a zeta potential of −26.5 mV, and a PDI of 0.45 with enhanced % EE. Rheology, spreadability, extrudability, in vitro release, skin permeation, molecular docking, antifungal, and antileishmanial activity were also assessed for VRCT and VRC loaded transethosomal gel (VTEG). Ex-vivo permeation using rat skin depicted a transdermal flux of 22.8 µg/cm²/h with enhanced efficiency up to 4-fold. A two-fold reduction in inhibitory as well as fungicidal concentration was observed against various fungal strains by VRCT and VTEG besides similar results against L-donovani. The development of transethosomal formulation can serve as an efficient drug delivery system through a topical route with enhanced efficacy and better patient compliance.     

Nanoparticles positioning effect on properties of (PS-PANI/NiNPs) nanocomposite films

This work presents the effect of driven nickel nanoparticles (NiNPs) towards the surface of (PS-PANI)/NiNPs nanocomposite upon the application of a uniform magnetic field. The purpose is to obtain distinguishable optoelectronic and electrical properties. This process increases the surface roughness and its reactivity, and enables the tuning of the optical and electrical properties. Based on the results from X-ray photoelectron and Fourier-transform infrared spectroscopies, the magnetically-driven NiNPs to the surface are oxidized, forming NiONPs and NiOHNPs. This oxidation effect transforms the surface from a hydrophilic to a hydrophobic state. In addition, the optical bandgap energy decreases from 4.04 to 3.77 eV, and the electrical conductivity increases from 12.77 μS/cm to 57.80 μS/cm and 77.52 μS/cm, for 50 and 100 mT magnetic fields, respectively, which is attributed to the well-dispersed magnetic nanoparticles in the PS-PANI polymer matrix, resulting in a high homogeneous nanocomposite film.     

Linear Symmetries of Scattering Amplitudes

If we define, roughly, linear symmetries as those symmetries which lead to linear relationships among scattering amplitudes, we are then faced with the question whether we already know all possible types of linear symmetries or whether there are new types of symmetries which we can yet discover. We argue that for an important class of these symmetries there can be no new types of symmetries, except for one which we call scaling symmetry. We also attempt to point out all types of symmetries which other classes have. In analyzing the above question we are led to a simple and consistent formalism for describing linear symmetries which takes linearity as the starting point for dealing with these symmetries. In this approach all linear symmetries are formally treated on an equal footing. General results on linear symmetries are derived: These symmetries are then classified into three main classes, and an effort is made to discover the characteristic properties of the individual classes.