Electromagnetic fields near plasmonic wedges

The behavior of electromagnetic fields near the edge of a plasmonic wedge is investigated. We study the scattering properties, field divergence, and field enhancement near an Au wedge bounded by SiO2 upon illumination by TM-polarized light using hypersingular integral equations, as a function of wavelength, wedge angle, and angle of incidence. The transverse scattered field components show a convergent behavior at wavelengths approaching the surface plasmon energy asymptote (on the corresponding flat Au-SiO2 interface), and become strongly divergent at longer wavelengths. The computed divergence is compared with Meixner's theory and is found to be in good agreement over a restricted range of parameters.     

Longitudinal analysis of novel Alzheimer's disease proteomic cerebrospinal fluid biomarkers during intravenous immunoglobulin therapy

Intravenous immunoglobulin (IVIg) therapy has shown promising results in treating Alzheimer's disease (AD). In this study, a Random Forest (RF) classification model was used to identify possible effects of IVIg on a group of eight subjects who underwent immunotherapy. Cerebrospinal fluid (CSF) samples from eight AD subjects who underwent IVIg therapy were collected before therapy, after 6 months of therapy, and after a 3-month drug washout period. Samples were analyzed using 2DE and further studied using a RF classification model to identify effects of IVIg on a panel of 23 putative diagnostic AD biomarkers previously identified. Six of the eight subjects showed improvements with respect to the 23 AD diagnostic biomarkers after 6 months of therapy compared to the samples taken at the outset of the trial. All subjects reverted back to baseline during drug washout. These results are also consistent with clinical observations. The observed improvements in subjects during 6 months of IVIg therapy and the reversion back to baseline during drug washout provides preliminary evidence regarding the potential use of IVIg as an AD immunotherapy.     

The influence of hydrophobic amino acid side groups on the acidity of the aromatic imidazole ring of histidine: A theoretical study

In this study we have calculated the acidity constant (pKa) of imidazole ring in Histidine‐Hydrophobic amino acid dipeptides using the quantum chemistry and continuum solvation methods. Density functional theory calculations with the large basis sets are used to determine the Gibbs free energy of deprotonate in the gas and liquid phases. Based on our results ΔG_S values are located between ?69.38 and ?18.82 kcal mol^?1 which are related to His⁺–Gly and His forms, respectively. pKa of the dipeptides in the aqueous phase was obtained from the calculated gas‐phase and solvation free energies through a thermodynamic cycle and the solvation model chemistry of Martin Karplus et al. Solvation effects are treated using a self‐consistent reaction field formalism involving polarized continuum models. According to our calculations pKa values are between 5.50 and 8.19 that are belong to His⁺–ILe and His⁺–Ala forms, respectively. Natural bond orbital analysis of dipeptides reveals that the electron delocalization in imidazole ring is the most effective factor in determination of acidity order for these compounds. Structural analysis confirmed that the orientation of carbonyl group with respect to imidazole ring is an effective factor in imidazole ring stability. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Interacting ghost dark energy in non-flat universe

A new dark energy model called “ghost dark energy” was recently suggested to explain the observed accelerating expansion of the universe. This model originates from the Veneziano ghost of QCD. The dark energy density is proportional to Hubble parameter, ρ _D  = α H, where α is a constant of order L_QCD³{\Lambda_{\rm QCD}^3} and Λ_QCD ~ 100 MeV is QCD mass scale. In this Letter, we extend the ghost dark energy model to the universe with spatial curvature in the presence of interaction between dark matter and dark energy. We study cosmological implications of this model in detail. In the absence of interaction the equation of state parameter of ghost dark energy is always w _D > −1 and mimics a cosmological constant in the late time, while it is possible to have w _D < −1 provided the interaction is taken into account. When k = 0, all previous results of ghost dark energy in flat universe are recovered. For the observational test, we use Supernova type Ia Gold sample, shift parameter of cosmic microwave background radiation and the correlation of acoustic oscillation on the last scattering surface and the baryonic acoustic peak from Sloan Digital Sky Survey are used to confine the value of free parameter of mentioned model.     

A Promising Material for Selective Sensing Biomarker Gas Molecules

Russian Journal of Physical Chemistry A - The interaction of many biomarker gas molecules on pure, AlB-doped and GaB-doped boron nitride nanotube was studied by the density functional theory method...     

Extended architectures constructed of thiourea-modified SBA-15 nanoreactor: A versatile new support for the fabrication of palladium pre-catalyst

We designed and synthesized a novel catalyst consisting of ordered mesoporous silica (SBA-15) functionalized with bis(thiourea) (BTU) linker. The regular and unique pore channels of BTU-SBA-15 ensure proper control of the size and homogeneous distribution of palladium nanoparticles. The physiochemical properties of the hybrid Pd@BTU-SBA-15 pre-catalyst were investigated using various techniques. The proposed catalyst is found to be very active, reusable, stable and scalable, and has excellent reactivity and selectivity for Suzuki and Heck coupling reactions under very mild and sustainable reaction conditions.     

Heat transfer intensification in microchannel by induced-charge electrokinetic phenomenon: a numerical study

Journal of Thermal Analysis and Calorimetry - In this numerical investigation, the induced-charge electrokinetic phenomenon is used to intensify the convective heat transfer rate in the...