A convenient synthesis of 4-amino-3,5-dialkyl-4H-1,2,4-triazoles

Ester tert-butoxycarbonylhydrazones 2 were reacted with some carboxylic acid hydrazides to give 4 -terrtutoxycarbonylamino-3,5-dialkyl-4H-1,2,4-triazoles 3–6 . Treatment of 3–5 with 6 N hydrochloric acid under mild conditions resulted in the formation of 4-ammo-3,5-dialkyl-4H-1,2,4-triazole hydrochlorides 7–9 in good yields. Compound 7a was converted to the free 4 -amino compound 10a upon treatment with ethanolic sodium ethoxide solution.     

Excimer emission and energy transfer in cofacial boradiazaindacene (BODIPY) dimers built on a xanthene scaffold

Using a rigid xanthene scaffold, a series of boradiazaindacene derivatives were synthesized. In some of these compounds, two boradiazaindacene derivatives were placed cofacially, resulting in significant inter-chromophoric interactions, including excimer emission. A simple modification of boradiazaindacene structure leads to formation of an ICT dye, which has distinct spectral properties. Energy transfer between two BODIPY dyes was demonstrated as well. In addition, the spectral properties of ICT dye can be modulated by the addition of the acid leading to an acid switchable energy transfer cassette.     

Synthesis,p-Nitrophenolate Complexation and Competitive Anion Signaling of Novel Calixpyrrole Dimer

A novel dimeric calixpyrrole has been synthesized. The dimer forms stable complexes with p-nitrophenolate ion with a concomitant reduction in extinction coefficient. The chromogenic anion is displaced by the addition of various anions like fluoride and acetate. Effective optical sensing of these anions is accomplished using the calixpyrrole dimer.     

Nucleophilic attack by bromide ions as a first step of conversion of Se(VI) to Se(IV)

Numerous commonly used analytical methods allow only determination of a total amount of selenium in a given sample. Electroanalytical methods as well as those based on hydride generation or on formation of piazselenol allow only determination of Se(IV). To determine Se(VI) by these procedures, present alone or in mixtures with Se(IV), it is first necessary to convert Se(VI) to Se(IV). Such conversion is effective in the presence of excess of halides in acidic media or by photoreduction. In the often used conversion of Se(VI) in the presence of chlorides or less frequently of that of bromides, it has been assumed that the halide ion acts as a reducing agent. Kinetic studies of conversion of Se(VI) in acidic solutions containing an excess of bromide ions indicated that the rate determining first step of the reaction with Se(VI) is a nucleophilic substitution of the OH₂⁺ group in the protonated form of H₂SeO₄ by bromide ions. For the overall reaction with rate −d[Se(VI)]/dt = k₁[H⁺][Br⁻]^1.15[Se(IV)] the rate constant 1 × 10⁻³ L² mol⁻² s⁻¹ was found. The following formation of Se(IV) from the bromo derivative is a fast reaction probably resulting in elimination of HBrO.     

Investigation of the Effects of Chemically Grafted Chitosan Nanofibers on P. aeruginosa PA01 Biofilm Formation Using Quartz Crystal Microbalance Technique

This study reports that quartz crystal microbalance (QCM) is used to determine the effect of chitosan derivatives obtained by chemical method on biofilm inhibition. Plasma grafted chitosan (pchito) was modified chemically with both 5-methyl-4-phenyl-thiophene-3-carboxylic acid (MFTKA) and 4-(thiophene-2-sulfonylamino)-benzoic acid (TSABA). The quartz crystal electrode surfaces were coated with nanofibers of these chitosan derivatives by QCM-electrospinning techniques. The surface morphology and elemental compositions of nanofibers were examined using Scanning electron microscopy-Energy dispersive X-ray spectroscopy (SEM-EDS). Inhibition of Pseudomonas aeruginosa PA01 as model bacteria on the electrodes coated with nanofiber was examined as a function of time using a flow-cell through QCM.     

Transfer Hydrogenation of Ketones Catalyzed by 1-Alkylbenzimidazole Ruthenium(II) Complexes

Summary. Six [RuCl₂(1-alkylbenzimidazole)(p-cymene)] complexes have been prepared and the new compounds characterized by C, H, N analyses, ¹H NMR, and ¹³C NMR. The reduction of ketones to alcohols via transfer hydrogenation was achieved with catalytic amounts of the complexes in the presence of t-BuOK.     

Investigation of temperature dependent electrical and impedance characteristics of bulk Zn0.95Co0.05O

Journal of Sol-Gel Science and Technology - Zn0.95Co0.05O was synthesized by sol-gel method and then Zn0.95Co0.05O pellet was prepared to investigate its structural, morphological, electrical, and...     

Interaction between Janus Green B and bovine serum albumin:Electrochemistry and spectroscopy studies

In this study,voltammetric and spectroscopic investigation of the interaction between Janus Green B(JGB) and bovine serum albumin(BSA) was reported.The interaction was observed at Britton-Robinson buffer(pH 7.0).When JGB was added to solution containing BSA,the peak currents of BSA decrease with the increasing of JGB concentrations which is due to the interaction of JGB and BSA.The binding constant of JGB with BSA was obtained by voltammetric data.Also,this interaction was supported by means of UV-vis spectroscopic measurements.The UV-vis absorption spectra of JGB in the presence of BSA decrease with the increasing of BSA concentrations.     

Investigation of classical and fractional Bose–Einstein condensation for harmonic potential

In this study, classical and fractional Gross–Pitaevskii (GP) equations were solved for harmonic potential and repulsive interactions between the boson particles using the Homotopy Perturbation Method (HPM) to investigate the ground state dynamics of Bose–Einstein Condensation (BEC). The purpose of writing fractional GP equations is to consider the system in a more realistic manner. The memory effects of non-Markovian processes involving long-range interactions between bosons with the restriction of the ergodic hypothesis and the effect of non-Gaussian distributions of bosons in the condensation can be taken into account with time fractional and space fractional GP equations, respectively. The obtained results of the fractional GP equations differ from the results of the classical one. While the Gauss distribution describing the homogeneous, reversible and unitary system is obtained from the classical GP equation, the probability density of the solution function of fractional GP equations is non-conserved. This situation describes the inhomogeneous, irreversible and non-unitary systems.     

Mathematical analysis and numerical simulations for the HSP70 synthesis model

The heat shock proteins (HSPs) protect the other proteins in the process of folding under stressful conditions such as oxygen deprivation, hypothermy or presence of alcohol. They have also an important role in tumour invasion. In this paper, the existence, uniqueness and permanence properties for the solution of the mathematical model which focuses on the synthesis of HSP70 is proved. Moreover the numerical simulations are performed by using FDM, namely a combination of backward and forward Euler methods, and the results confirm the expected behaviour of the solution.