Chemistry

Electronic spectra and intersystem spin-orbit coupling in 1,2- and 1,3-squaraines
The main photophysical properties of a series of recently synthetized 1,2- and 1,3-squaraines, including absorption electronic spectra, singlet-triplet energy gaps, and spin-orbit matrix elements, have been investigated by means of density functional theory (DFT) and time-dependent DFT approaches. A benchmark of three exchange-correlation functionals has been performed in six different solvent ...


Synergistic Effect of Nickel Species and γ-Alumina Added to HZSM-5 on the Methanol to Aromatics
Ni/HZSM-5 catalysts with γ-alumina were prepared by the sol–gel method. At first, reaction performances were investigated over the HZSM-5 catalysts with and without γ-alumina. Then, reaction evaluations were conducted over the Ni/HZSM (different loading amounts of nickel species were investigated) catalysts with and without γ-alumina. The addition of nickel species and γ-alumina increased...
Aptamer-based electrochemical assay of 17β-estradiol using a glassy carbon electrode modified with copper sulfide nanosheets and gold nanoparticles, and applying enzyme-based signal amplification
We have developed an electrochemical method for the determination of 17β-estradiol. A glassy carbon electrode was modified with a composite made from copper sulfide nanosheets, gold nanoparticles, and glucose oxidase. The copper sulfide nanosheet was prepared by a single-step hydrothermal process, and its properties were characterized by X-ray powder diffraction, X-ray photoelectron spectrosco...


Colorimetric and visual determination of total nereistoxin-related insecticides by exploiting a nereistoxin-driven aggregation of gold nanoparticles
We describe a method for the visual and colorimetric determination of total nereistoxin-related insecticide residues. It is based on the nereistoxin-induced aggregation of gold nanoparticles (AuNPs). The nereistoxin-related insecticides are first converted to nereistoxins in a pretreatment step that involves liquid–liquid extraction and hydrolysis for sample clean-up. Next, the interaction be...
PNA-based DNA assay with attomolar detection limit based on polygalacturonic acid mediated in-situ deposition of metallic silver on a gold electrode
An electrochemical method is described for the ultrasensitive determination of sequence-specific DNA by using polysaccharide-mediated in-situ deposition of metallic silver on a gold electrode. Specifically, a thiolated peptide nucleic acid (PNA) is immobilized on the gold electrode via formation of a self-assembled monolayer. Following hybridization between PNA and target single-stranded DNA (s...


Determination of ATP by resonance light scattering using a binuclear uranyl complex and aptamer modified gold nanoparticles as optical probes
We describe a resonance light scattering (RLS) method for the direct detection of adenosine triphosphate (ATP) in aqueous solution without the need for separation. The binuclear uranyl complex bis-uranyl-bis-sulfosalophen (BUBSS) was synthesized by the coordination reaction of two uranyl ions with the ditopic tetradentate ligand bis-sulfosalophen. In parallel, gold nanoparticles were modified w...
Effective mass of a two-dimensional √3×√3 Ga single atomic layer on Si(111)
The effective mass of the empty conduction band surface state of a single atomic √3×√3 Ga layer on Si(111) is determined using scanning tunneling spectra. The methodology is based on calculating the tunnel current using its dependence on the effective density of state mass and a parabolic band approximation followed by fitting to the measured tunneling spectra. An effective mass of m eff,C...

Surface energy and work function of fcc and bcc crystals: Density functional study
The surface energies and work functions for six close-packed surfaces of 19 common fcc and bcc metals in the periodic table have been systematically calculated by means of the density functional theory (DFT) method. The accuracy of the results is established in comparison with the experimental and other theoretical values. The variations of work functions with the surface crystallographic orien...
A comparative study of the He–Sb(111) interaction potential from close-coupling calculations and helium atom scattering experiments
The exact elastic close-coupling formalism is used to compare the performance of several interaction potentials suggested in literature for describing the measured elastic diffraction peak intensities in helium scattering experiments. The coupling parameters have been analytically calculated for the corrugated Morse potential on a hexagonal surface structure and adapted for usage with similar i...

Kohn–Sham theory in the presence of magnetic field
In the well-known Kohn–Sham theory in density functional theory, a fictitious non-interacting system is introduced that has the same particle density as a system of (N) electrons subjected to mutual Coulomb repulsion and an external electric field. For a long time, the treatment of the kinetic energy was not correct and the theory was not well-defined for (N)-representable particle densities....
A constructive approach to quasi-steady state reductions
We present a method to determine the reduction of a (polynomial or rational) ordinary differential equation that models a chemically reacting system, under the assumption that this system admits quasi-steady state (QSS) behavior for certain variables or reactions. We interpret QSS mathematically as a singular perturbation setting to which the classical theorems of Tikhonov and Fenichel apply. B...

Novel Sustained-Release of Propafenone through Pellets: Preparation and in Vitro/in Vivo Evaluation
In this study, an extrusion-spheronization method was applied successfully to fabricate propafenone hydrochloride (PPF) sustained-release pellets. Using scanning electron microscopy, it was shown that the PPF pellets had a mean size of approximately 950 µm with a spherical shape. The in vitro release profiles indicated that the release of PPF from the pellets exhibited a sustained release beha...
Resveratrol Induces the Expression of Interleukin-10 and Brain-Derived Neurotrophic Factor in BV2 Microglia under Hypoxia
Microglia are the resident macrophages of the central nervous system (CNS) and play an important role in neuronal recovery by scavenging damaged neurons. However, overactivation of microglia leads to neuronal death that is associated with CNS disorders. Therefore, regulation of microglial activation has been suggested to be an important target for treatment of CNS diseases. In the present study...
Expression Profiling of Exosomal miRNAs Derived from Human Esophageal Cancer Cells by Solexa High-Throughput Sequencing
Cellular genetic materials, such as microRNAs (miRNAs), mRNAs and proteins, are packaged inside exosomes, small membrane vesicles of endocytic origin that are released into the extracellular environment. These cellular genetic materials can be delivered into recipient cells, where they exert their respective biological effects. However, the miRNA profiles and biological functions of exosomes se...
Palladium-Catalyzed Decarbonylative Rearrangement of N-Allenyl Seleno- and Tellurocarbamates
Decarbonylative rearrangement of seleno- and tellurocarbamates carrying an allenyl group on the nitrogen was found to proceed in the presence of a palladium catalyst to afford 3-chalcogeno-1-azadienes. This transformation may involve oxidative addition of Pd to a carbon–chalcogen bond, decarbonylation from a carbamoylpalladium unit (R2N-C(O)-PdChPh: Ch = Se or Te), Pd shift, and reductive eli...