Some Analytical Solutions for Groundwater Flow and Transport Equation

This paper presents the use of symmetry reduction method resulting in new exact solutions for the groundwater flow and transport equation. It is assumed that the radionuclides are transported by advection-diffusion in a single fracture and diffusion in the surrounding rock-matrix. The application of one-parameter group reduces the number of independent variables, and consequently the governing PDE of (1+2)-dimension reduces to set of ODEs which are solved analytically. This enables us to present some new exact time-dependent solutions of the advection-diffusion equation.     

Syntheses and Investigation of Some New Polyarylates and Copolyarylates. Part I

By the interfacial condensation of acid chlorides I, II, and III, respectively, with bifunctional phenols (IV-X), soluble or mold-able thermostable polyarylates were obtained. Similarly, copolyarylates were prepared from a mixture of the acid chlorides I + II or I + III. With bisphenol-A (VIII), soluble polymers are usually obtained. Methylene dichloride and/or carbon tetra-chloride-water systems were the best media for interfacial condensations, and the polymers formed showed the highest reduced viscosity values.

Polyester films are useful in many industrial applications because of their broad range of mechanical, optical, and electrical properties. The aromatic polyesters‐polyarylates-dominate the field of industrial polyester films [1].

Polyarylates prepared from dihydric phenols and purely aromatic dicarboxylic acid chlorides are highly heat resistant materials [2], but they are insoluble and nonmoldable [3]. However, by the introduction of ether linkages in the aromatic dicarboxylic acid moiety, soluble and/or moldable polyamides were obtained [4].     

Designing Functionally Substituted Pyridine-Carbohydrazides for Potent Antibacterial and Devouring Antifungal Effect on Multidrug Resistant (MDR) Strains

The emergence of multidrug-resistant (MDR) pathogens and the gradual depletion of available antibiotics have exacerbated the need for novel antimicrobial agents with minimal toxicity. Herein, we report functionally substituted pyridine carbohydrazide with remarkable antimicrobial effect on multi-drug resistant strains. In the series, compound 6 had potent activity against four MDR strains of Candida spp., with minimum inhibitory concentration (MIC) values being in the range of 16–24 µg/mL and percentage inhibition up to 92.57%, which was exceptional when compared to broad-spectrum antifungal drug fluconazole (MIC = 20 µg/mL, 81.88% inhibition). Substitution of the octyl chain in 6 with a shorter butyl chain resulted in a significant anti-bacterial effect of 4 against Pseudomonas aeruginosa (ATCC 27853), the MIC value being 2-fold superior to the standard combination of ampicillin/cloxacillin. Time-kill kinetics assays were used to discern the efficacy and pharmacodynamics of the potent compounds. Further, hemolysis tests confirmed that both compounds had better safety profiles than the standard drugs. Besides, molecular docking simulations were used to further explore their mode of interaction with target proteins. Overall results suggest that these compounds have the potential to become promising antimicrobial drugs against MDR strains.     

Finite difference scheme for variational inequalities

In this paper, we show that a class of variational inequalities related with odd-order obstacle problems can be characterized by a system of differential equations, which are solved using the finite difference scheme. The variational inequality formulation is used to discuss the uniqueness and existence of the solution of the obstacle problems.     

Synthesis,reactions, and antimicrobial activity of some novel fused thiazolo[3,2-<Emphasis Type="Italic">a</Emphasis>]pyrimidine-5<Emphasis Type="Italic">H</Emphasis>-indeno[1,2-<Emphasis Type="Italic">d</Emphasis>]pyrimidine derivatives

Series of novel substituted thioxopyrimidine and thiazolo[3,2-a]pyrimidine compounds that combine various heteroaryl rings have been synthesized via Biginelli one-pot three-component reaction and elucidated with chemical and spectral analysis. Several products were tested for their antimicrobial properties.     

Spectrophotometric and spectrofluorimetric methods for the determination of tranexamic acid in pharmaceutical formulation

Two simple and sensitive spectrophotometric and fluorimetric methods for the determination of tranexamic acid in tablets are developed. The methods are based on condensation the primary amino group of tranexamic acid with acetyl acetone and formaldehyde producing a yellow coloured product, which is measured spectrophotometrically at 335 nm or fluorimetrically at 480 nm the colour was stable for at least 1 h. Beer's law was valid within a concentration rang of 0.05-2.0 microg ml-1 spectrophotometrically and 0.05-0.25 microg ml-1 fluorimetrically. All the variables were studied to optimize the reaction conditions. No interference was observed in the presence of common pharmaceutical excipints. The validity of both methods was tested by analyzing tranexamic acid in its pharmaceutical preparations. Good recoveries were obtained and the results were comparable with those obtained by standard method.