Molecular Docking Studies and Biological Evaluation of Berberine–Benzothiazole Derivatives as an Anti-Influenza Agent via Blocking of Neuraminidase

In this study, we have introduced newly synthesized substituted benzothiazole based berberine derivatives that have been analyzed for their in vitro and in silico biological properties. The activity towards various kinds of influenza virus strains by employing the cytopathic effect (CPE) and sulforhodamine B (SRB) assay. Several berberine–benzothiazole derivatives (BBDs), such as BBD1, BBD3, BBD4, BBD5, BBD7, and BBD11, demonstrated interesting anti-influenza virus activity on influenza A viruses (A/PR/8/34, A/Vic/3/75) and influenza B viral (B/Lee/40, and B/Maryland/1/59) strain, respectively. Furthermore, by testing neuraminidase activity (NA) with the neuraminidase assay kit, it was identified that BBD7 has potent neuraminidase activity. The molecular docking analysis further suggests that the BBD1–BBD14 compounds’ antiviral activity may be because of interaction with residues of NA, and the same as in oseltamivir.     

Fabrication of dense Ce0.9Mg0.1P2O7-PmOn composites by microwave heating for application as electrolyte in intermediate-temperature fuel cells

In the present work, we report a method of fabrication of dense 10 mol% Mg²⁺-doped cerium pyrophosphate-phosphate (Ce_0.9Mg_0.1P₂O₇-P_mO_n; CMP-P) composites by microwave heat-treatment of the preformed Ce_0.9Mg_0.1P₂O₇ substrates in the presence of phosphoric acid. The composite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The microwave heating at 375 °C for 5 min resulted in the formation of dense CMP-P composites which retained most of the pyrophosphate phase. The electrical conductivity was extracted from the EIS data and for the CMP-P composite prepared by H₃PO₄ loading for 10 h and microwave heat-treatment for 5 min it was found to be >10^?2 S m^?1 in 100–250 °C range with a maximum of 0.062 S cm^?1 at 190 °C, which was significant for its application as electrolyte in intermediate temperature fuel cells.     

Drug‐loaded polyurethane/clay nanocomposite nanofibers for topical drug‐delivery application

In this study, polyurethane/nanoclay nanocomposite nanofibrous webs were prepared by electrospinning. An antiseptic drug, chlorhexidine acetate (CA), was loaded onto montmorillonite clay and was then incorporated into polyurethane nanofibers. For comparison, the CA drug was loaded directly into the polyurethane solution dope used to electrospin the nanofibers. The emphasis was on investigating the effect of the drug loading into the nanoclay vis‐à‐vis direct drug loading on the drug‐release behavior of nanofibrous webs. The nanofibrous webs were also evaluated for other properties, such as moisture vapor transmission, porosity determination, contact angle measurement, and antibacterial activity, which are important for topical drug‐delivery application. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40230.     

Study of electrochemical hydrogen charge/discharge properties of FePO4 for application as negative electrodes in hydrogen batteries

We report the electrochemical hydrogen charge/discharge properties of electrodes containing crystalline and amorphous FePO₄ as active material in KOH electrolyte. Crystalline and amorphous FePO₄ were synthesized by an alcohol-assisted precipitation method, and the powders obtained were characterized by X-ray diffraction. X-ray photoelectron spectroscopy is used to investigate the mechanism of hydrogen charge/discharge behavior of FePO₄. The electrochemical hydrogen charge/discharge properties of electrodes containing crystalline and amorphous FePO₄ were investigated for potential application as negative electrodes in rechargeable hydrogen batteries. In galvanostatic discharge/charge mode at 25 °C, the crystalline FePO₄ showed a maximum discharge capacity of 109 mA h g⁻¹, while the amorphous FePO₄ showed a maximum discharge capacity of 81.4 mA h g⁻¹. The electrochemical kinetic properties, exchange current density, and proton diffusivity were calculated using linear polarization measurement and the potential-step method.     

Use of Fourier transform infrared spectroscopy to study ageing characteristics of asphalt binders

The present study aims at studying ageing characteristics of conventional bitumen, polymer modified bitumen (PMB) and warm mix asphalt (WMA) by using FTIR. Results of obtained FTIR spectrum were quantified by calculating different indices and finally based on these indices ageing index of the binders for short- and long-term ageing were calculated. Results showed ageing increased amount of complex and high molecular weight components of the binders. PMB was found to have greater ageing resistance than conventional asphalt binders. In case of WMA, results found to be inconclusive, requiring further investigation.     

An experimental study for optimizing the energy efficiency of a proton exchange membrane fuel cell with an open-cathode

To develop an operating strategy for maximizing the energy efficiency of open-cathode proton exchange membrane fuel cells (OCPEMFCs), the present study investigates the effect of the fan speed on the stack performance and energy efficiency using a commercially available OCPEMFC system. The temperature, voltage, and current of the stack are monitored, and the energy efficiency is calculated at various stack power levels. The results of the system with a lab-developed controller are compared with the commercial system with a built-in controller. It is found that the fan speed should be minimum to reduce the auxiliary power consumption and that the stack should be efficiently heated to enhance the electrochemical reaction. In addition, it is noticed that the stack performance dramatically drops when the stack temperature is above 75 °C, due to the membrane dehydration. Overall, the results show that the stack temperature is an important indicator for controlling the fan speed for optimization of energy efficiency, and for stack powers of 50, 60, 70, and 80 W, the peak values of energy efficiencies are 38.0%, 38.3%, 38.5%, and 38.3% at the duty cycles of 0.2, 0.2, 0.25, and 0.3, respectively, which are 28–38% higher than the commercially available OCPEMFC system.     

Modeling breakage and motion of black pepper seeds in cryogenic mill

The present investigation aims to represent three-dimensional motion and breakage phenomena of black pepper seeds in the cryogenic mill (hammer mill) using discrete element method (DEM). In DEM modeling, bonded particle model was coupled with Hertz-Mindlin contact model. Calibration method was used to select appropriate model (bond) parameters. The calibrated set of bond parameters includes 3.12?×?10¹¹?Pa?m^?1 normal stiffness; 1.56?×?10¹¹?Pa?m^?1 shear stiffness; 3.88?×?10⁸?Pa critical normal stiffness; 1.94?×?10⁸?Pa critical shear stiffness. Besides, the validity of calibrated parameters was tested in the hammer mill. The observed qualitative and quantitative results (breakage and flow pattern) of numerical and experimental approaches were in good agreement. Based on these results, a few prefatory suggestions were provided to improve the design aspects of the mill. Overall, DEM modeling offered a better understanding of particle breakage and flow pattern in the mill.     

Polyurethane/clay nanocomposites with improved helium gas barrier and mechanical properties: Direct versus master‐batch melt mixing route

Thermoplastic polyurethane (TPU)/clay nanocomposite films were produced by incorporation of organo‐modified montmorillonite clay (Cloisite 30B) in TPU matrix by two different melt‐mixing routes (direct and master‐batch‐based mixing), followed by compression molding. In master‐batch mixing where the master‐batch was prepared by mixing of clay and TPU in a solvent, better dispersion of clay‐layers was observed in comparison to the nanocomposites produced by direct mixing. As a consequence, superior mechanical and gas barrier properties were obtained by master‐batch mixing route. The master‐batch processing resulted in 284 and 236% increase in tearing strength and tearing energy, respectively, with 5 wt % clay‐loading. Interestingly, in case of master‐batch mixing, the tensile strength, stiffness as well as breaking extension increased simultaneously up to 3 wt % clay‐loading. The helium gas permeability reduced by about 39 and 31% for the TPU/clay nanocomposites produced by mater‐batch and direct mixing routes, respectively, at 3 wt % loading of clay. Finally, the gas permeability results have been compared using three different gas permeability models and a good correlation was observed at lower volume fraction of clay. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46422.