First integrals and exact solutions of the SIRI and tuberculosis models

The first integrals and exact solutions of mathematical models of epidemiology: a susceptible‐infected‐recovered‐infected (SIRI) model and a tuberculosis model with demographic growth are analyzed. These models are represented by systems of first‐order nonlinear ordinary differential equations, and this system is replaced by one which contains a second‐order ordinary differential equation. The partial Lagrangian approach is then utilized to derive the first integrals of these models. Several cases arise. Then, we utilize the derived first integrals to construct exact solutions for the models under investigation and determine new solutions. The dynamic properties of these models are studied too. Copyright © 2016 John Wiley & Sons, Ltd.     

A facile approach towards synthesis,characterization, single crystal structure,and DFT study of 5-bromosalicylalcohol

5-Bromosalicylalcohol was prepared by the interaction of NaBH₄ and 5-bromosalicylaldehyde. The use of sodium borohydride makes the reaction easy, facile, economic and does not require any toxic catalyst. The compound is characterized by FTIR, ¹H NMR, ¹³C NMR, TEM and ESI-mass spectra. Crystal structure is determined by single crystal X-ray analysis. Quantum mechanical calculations of geometries, energies and thermodynamic parameters are carried out using density functional theory (DFT/B3LYP) method with 6-311G(d,p) basis set. The optimized geometrical parameters obtained by B3LYP method show good agreement with experimental data.     

Multifunctional Magnetic Nanomedicine Drug Delivery and Imaging-Based Diagnostic Systems

Magnetically guided drug transportation is a technique in which magnetic pharmaceutical transporters in organisms are controlled by applied magnetic forces to deliver drugs to the desired location. Different magnetic drug delivery systems (MDDSs) are developed to treat a variety of illnesses, particularly cancer and neurological disorders. However, a unique magnetic setup is required in each application for an effective magnetically guided drug aiming to direct the drug-carrying nanocarriers to the intended area. The current and future perspectives of MDDS are investigated in this study by considering their biological functions, deliverable efficiency, complexity, and the nature of the externally applied magnetic field. Despite the fact that MDDSs have low cytotoxicity, regulated magneto reactivity, extended circulation lifespan, and high surface stability, very few clinical studies have been conducted to date in order to achieve optimized therapeutic efficacy before entering the market. In recent studies, the development of novel magnetic medication transporting carriers is preferred over direct magnetic medication administration. Better functional magnetic targeting technologies are required for such breakthroughs to enter clinical trials. Because MDDSs are unlikely to work in all clinical situations, more focused research is needed to replace or improve the strategy for treating multiple illnesses.     

Smart Therapeutic Strategy of pH-Responsive Gold Nanoparticles for Combating Multidrug Resistance

As several multi-target drug delivery approaches are successfully identified through preclinical screening, their clinical success is often hampered by challenges such as poor circulation stability, dissimilarities in the pharmacokinetics of different drugs, as well as targeting inefficiency. Gold nanoparticles (AuNPs) are adopted as promising nanocarriers in the co-delivery of multiple therapeutic drugs for combination therapy. The pH-responsive AuNPs are synthesized and incorporated with multiple chemotherapeutic drugs, such as doxorubicin and bleomycin. Such structures can work as drug carriers to treat cervical carcinoma by adopting a quality by design approach. The designed nanocarrier is characterized by adopting a range of physicochemical and morphological techniques. In vitro drug release and cytotoxicity of optimized nanocarriers are assessed to cervical tumor epithelial cells. The results highlight the notable advantages of colloidal AuNPs, including sustained drug release, therapeutic agent delivery with high stability, and biocompatibility for more effective treatment of cervical carcinoma. Furthermore, by improving the biodistribution and/or bioavailability profiles, it is believed that the two-in-one approach may therefore give evidence on the fate of co-loaded nanocarrier as a promising trajectory for successful clinical translation against ovarian carcinoma to achieve maximum therapeutic synergy for an individual patient.     

Synthesis of organic sulfobetaine‐based polymer gel electrolyte for dye‐sensitized solar cell application

We have synthesized eco‐friendly, economic, and equally efficient polysulfobetaine‐based gel electrolyte to the alternative of liquid electrolyte in the fabrication of dye‐sensitized solar cells (DSSCs) for the first time. This nitrogen‐rich and highly conductive polysulfobetaine was synthesized by an easy and facile method without the use of any catalyst and explored for its DSSC application. The synthesized polymer gel electrolyte exhibited good ionic conductivity about 6.8 × 10^?3 Scm^?1 at ambient temperatures. DSSCs were fabricated based on this polysulfobetaine gel electrolyte and studied for their performance based on photovoltaic parameters. The DSSC photovoltaic results were appreciable and are Voc = 0.82 V, Jsc = 11.49 mA/cm², FF = 66%, and PCE = 6.26% at 1 sun intensity. These values are slightly lower than conventional liquid electrolyte‐based DSSC shown as Voc = 0.78 V, Jsc = 12.90 mA/cm², FF = 69%, and PCE = 7.07%, both at 100 mWcm^?2. Conductivity and photovoltaic parameters of the device reveals that as prepared polysulfobetaine‐based polymer gel electrolyte may be useful in the fabrication of DSSC and other electrochemical devices. Copyright © 2017 John Wiley & Sons, Ltd.     

Approximate partial Noether operators and first integrals for cubically coupled nonlinear Duffing oscillators subject to a periodically driven force

The approximate first integrals for a system of two cubically coupled nonlinear Duffing oscillators subject to a periodically driven force are constructed with the help of approximate partial Noether approach. Firstly, approximate partial Noether operators associated with a partial Lagrangian are derived. Then approximate first integrals are obtained for both the resonant and non-resonant cases.     

Antibacterial, antifungal, antispasmodic and Ca++ antagonist effects of Caesalpinia bonducella

Caesalpinia bonducella F. (Leguminosae) has been used as a folk medicine for a variety of ailments. The crude extract of C. bonducella and its fractions were studied for antibacterial, antifungal, antispasmodic and Ca++ antagonistic properties. The strongest antibacterial effect was displayed by the n-butanol (72%) and ethyl acetate (80%) fractions, followed by the crude extract (46% and 42%), against Escherichia coli and Bacillus subtilis, respectively. The plant extract and its fractions showed mild to excellent activity in antifungal bioassays, with maximum antifungal activity against Candida glaberata (80%) and Aspergillus flavus (70%) by the n-butanol and chloroform fractions, followed by the crude extract (70% and 65%). Caesalpinia bonducella extract caused concentration-dependent inhibition of spontaneous and high K+ (80 mM)-induced contractions of isolated rabbit jejunum preparations, similar to that caused by Verapamil. These results indicate that C. bonducella exhibits antibacterial, antifungal, spasmolytic and Ca++ channel blocking actions.     

Antimicrobial, antileishmanial and cytotoxic compounds from Piper chaba

The petroleum ether and chloroform extracts of the root of Piper chaba showed antimicrobial, antileishmanial and cytotoxic activities. Further bioactivity-guided fractionation led to the isolation of Bornyl piperate (1), piperlonguminine (2) and piperine (3). This is the first report of isolation of compounds (1) and (2) from P. chaba. It was observed that the isolated compounds (1 and 2) showed potent antifungal activity when compared with standard drug Nystatin, and significant cytotoxic activity with the IC?? values of 0.76 and 0.83?μg?mL?1, respectively. These compounds were also found to have weak antibacterial and antileishmanial activities. This is the first report about the antileishmanial activity of Piper isolates.     

MHD stagnation flow of a micropolar fluid through a porous medium

The unsteady MHD boundary layer flow of a micropolar fluid near the forward stagnation point of a two dimensional plane surface is investigated by using similarity transformations. The transformed nonlinear differential equations are solved by an analytic method, namely homotopy analysis method (HAM). The solution is valid for all values of time. The effect of MHD and porous medium, non dimensional velocity and the microrotation are presented graphically and discussed. The coefficient of skin friction is also presented graphically.