On the performance of West’s bubble test: A simulation approach

In this research we examine the ability of West’s bubble test [1] in detecting speculative bubbles using Brock’s (1982) [2] intertemporal general equilibrium model of asset pricing as the basis for a simulation study. In this setting, (1) the economy, by construction is efficient and produces the maximally possible amount of welfare for society, and (2) asset prices reflect the utility-maximizing behavior of consumers and the profit-maximizing behavior of firms. We find that the West’s bubble test flag as “bubbles” in the simulated data yet the data is produced from an economy in which markets are efficient in welfare production.     

Adsorption and kinetic studies of cationic and anionic dyes on pyrophyllite from aqueous solutions

The adsorption of cationic Methylene Blue (MB) and anionic Procion Crimson H-EXL (PC) dyes from aqueous medium on pyrophyllite was studied. Changes in the electrokinetics of pyrophyllite as a function of pH were investigated in the absence and presence of multivalent cations. The results show that pyrophyllite in water exhibits a negative surface charge within the range pH 2-12. Pyrophyllite is found to be a novel adsorbent for versatile removal of cationic and anionic dyes. The negative hydrophilic surface sites of pyrophyllite are responsible for the adsorption of cationic MB molecules. The adsorption of anionic PC dye is possible after a charge reversal by the addition of trivalent cation of Al. Nearly 2 min of contact time are found to be sufficient for the adsorption of both dyes to reach equilibrium. The experimental data follow a Langmuir isotherm with adsorption capacities of 70.42 and 71.43 mg dye per gram of pyrophyllite for MB and PC, respectively. For the adsorption of both MB and PC dyes, the pseudo-second-order chemical reaction kinetics provides the best correlation of the experimental data.     

Synthesis and Characterization of Disulfide-Schiff Base Derivatives and <Emphasis Type="Italic">in vitro</Emphasis> Investigation of Their Antibacterial Activity Against Multidrug-Resistant <Emphasis Type="Italic">Acinetobacter baumannii</Emphasis> Isolates: A New Study

In this study two different methods without a catalyst and with a CeO₂ nano catalyst were used for the synthesis of dimeric disulfide-Schiff bases. The dimeric disulfide-Schiff base derivatives were characterized by FT-IR, NMR, and MS spectra, and elemental analysis. The disulfide-Schiff bases and their derivatives 2–5c were screened for in vitro antibacterial activity against 40 multidrug-resistant strains of Acinetobacter baumannii, and their minimum inhibitory concentrations were determined. Most of products exhibited high antibacterial activity against Acinetobacter baumannii.     

Fabrication of Thymoquinone‐Loaded Albumin Nanoparticles by Microfluidic Particle Synthesis and Their Effect on Planarian Regeneration

Thymoquinone is the main bioactive component of the plant Nigella sativa, which is commonly known as black seeds and has several therapeutic effects. However, clinical applications of thymoquinone are limited due to its hydrophobic nature. In this study, thymoquinone is encapsulated in albumin nanoparticles by using a microfluidic platform to overcome this limitation. The mean particle sizes of empty and thymoquinone‐loaded nanoparticles are determined as 271.3 and 315.6 nm, respectively, with polydispersity index values both lower than 0.25. In addition to particle size distribution measurements, characterizations of the prepared nanoparticles such as zeta potential measurements, in vitro release studies, as well as scanning electron microscopy, Fourier‐transform infrared, and differential scanning calorimetry analyses are also carried out. To determine the effect of thymoquinone on neural regeneration, planarians are used as the model organism. After application of free and encapsulated thymoquinone, planarians are amputated and the fragments are observed in terms of head and tail regeneration, swimming pattern, and behavior. The results indicate that thymoquinone affects their behavior and primarily enhances head regeneration of planarians. In addition, it is shown that encapsulation of thymoquinone not only enhances the thermal stability of the molecule but also decreases its toxicity.