One‐pot green synthesis and structural characterisation of silver nanoparticles using aqueous leaves extract of Carissa carandas : antioxidant,anticancer and antibacterial activities

Facile green synthesis of silver nanoparticles (AgNPs) using an aqueous extract of Carissa carandas (C. carandas) leaves was studied. Fabrication of AgNPs was confirmed by the UV–visible spectroscopy which gives absorption maxima at 420 nm. C. carandas leaves are the rich source of the bioactive molecules, acts as a reducing and stabilising agent in AgNPs, confirmed by Fourier transforms infrared spectroscopy. The field emission scanning electron microscope revealed the spherical shape of biosynthesised AgNPs. A distinctive peak of silver at 3 keV was determined by energy dispersive X‐ray spectroscopy. X‐ray diffraction showed the facecentred cubic structure of biosynthesised AgNPs and thermal stability was confirmed by the thermogravimetric analysis. Total flavonoid and total phenolic contents were evaluated in biosynthesised AgNPs. Biosynthesised AgNPs showed free radical scavenging activities against 2, 2‐diphenyl‐1‐picrylhydrazyl test and ferric reducing antioxidant power assay. In vitro cytotoxicity against hepatic cell lines (HUH‐7) and renal cell lines (HEK‐293) were also assessed. Finally, biosynthesised AgNPs were scrutinised for their antibacterial activity against methicillin‐resistant Staphylococcus aureus, Shigella sonnei, Shigella boydii and Salmonella typhimurium. This study demonstrated the biofabrication of AgNPs by using C. carandas leaves extract and a potential in vitro biological application as antioxidant, anticancer and antibacterial agents.Inspec keywords: antibacterial activity, biomedical materials, cancer, tumours, nanomedicine, silver, nanoparticles, reduction (chemical), nanofabrication, ultraviolet spectra, visible spectra, field emission scanning electron microscopy, Fourier transform infrared spectra, X‐ray chemical analysis, X‐ray diffraction, thermal stability, thermal analysis, free radical reactions, toxicology, cellular biophysics, microorganismsOther keywords: total phenolic contents, free radical scavenging activities, 2,2‐diphenyl‐1‐picrylhydrazyl test, ferric reducing antioxidant power assay, in vitro cytotoxicity, hepatic cell lines HUH‐7, renal cell lines HEK‐293, antibacterial activity, methicillin‐resistant Staphylococcus aureus, Shigella sonnei, Shigella boydii, Salmonella typhimurium, biofabrication, in vitro biological application, Ag, total flavonoid contents, thermogravimetric analysis, thermal stability, face‐centred cubic structure, X‐ray diffraction, energy dispersive X‐ray spectroscopy, distinctive peak, spherical shape, field emission scanning electron microscope, Fourier transforms infrared spectroscopy, stabilising agent, reducing agent, bioactive molecules, absorption maxima, UV‐visible spectroscopy, plant extract colour, antibacterial activities, anticancer activities, antioxidant activities, Carissa carandas, aqueous leaves extract, silver nanoparticles, structural characterisation, one‐pot green synthesis     

Preparation and evaluation of floating tablets of pregabalin

Abstract

Floating tablets of pregabalin were prepared using different concentrations of the gums (xanthan gum and guar gum), Carbopol 974P NF and HPMC K100. Optimized formulations were studied for physical tests, floating time, swelling behavior, in vitro release studies and stability studies. In vitro drug release was higher for tablet batches containing guar and xanthan gum as compared to the batches containing Carbopol 974P NF. Tablet batches were subjected to stability studies and evaluated by different parameters (drug release, drug content, FTIR and DSC studies). The optimized tablet batch was selected for in vivo pharmacodynamic studies (PTZ induced seizures). The results obtained showed that the onset of jerks and clonus were delayed and extensor phase was abolished with time in treated groups. A significant difference (p?>?0.05) was observed in control and treated group behavior indicating an excellent activity of the formulation for a longer period (>12?h).     

Percolation threshold and conductivity of polymer electrolyte composites: Effect of dispersoid particle size

Silica particles of different diameters (0.007, 0.014, and 44 μm) have been dispersed in polymer electrolyte (PEO:NH₄I) to form composites, and their electrical and thermal behavior have been studied. This article reports the occurrence of two peaks in the plot of conductivity as a function of the amount of dispersoid (SiO₂). Further, it is shown that the percolation threshold and the extent of maximum conductivity enhancement in the composites depend on the particle size of the dispersoid. The role of degree of crystallinity/amorphicity of the composites in modifying the conductivity of the composites has also been discussed and a phenomenological explanation is being proposed. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Conservation of historic water systems in Champaner-Pavagadh,Gujarat, India

Champaner-Pavagadh, a UNESCO World Heritage Site in Gujarat, is an interesting and unusual case study in how religion, culture, terrain, and climate interact in creating water systems that sustained large communities for 800 years between the eighth and sixteenth centuries. Water is central to Hindu worship rituals and at Pavagadh Hill, embodiment of the goddess Kalika, is symbolic of her nurturing aspects. The ornate water architecture of Champaner city at the foothill, inhabited by Muslims, celebrated water not for its symbolic value but for its sensual and utilitarian aspects. In ‘water-intelligent’ settlement planning at Champaner-Pavagadh, historic water catchment and conveyance systems ensured availability of water throughout the year. The article concludes with outlining the landscape approach to sustainable heritage landscape conservation within which water systems are restored and made functional, to serve the needs of local residents and pilgrims, and to enhance the legibility of this complex and layered site.     

Short term generation scheduling of cascaded hydro electric system using novel self adaptive inertia weight PSO

Hydro power plants are multipurpose projects, which are not only generating power but also responsible for the fulfillment of irrigation requirements of nearby zone. To harness the potential energy of released water Canal Head Power Houses (CHPHs) are also located at irrigation canals of the multipurpose projects. The present paper proposed a Novel Self Adaptive Inertia Weight Particle Swarm Optimization (NSAIW_PSO) approach to determine the optimal generation schedule of real operated cascaded hydroelectric system located at Narmada river in Madhya Pradesh, India. Here generation scheduling problem has been formulated in two cases. Case one considers natural inflows, evaporation losses and irrigation requirements assuming no generation through CHPHs. Whereas second case considers all above factors along with generation through CHPHs. Results show that in case two the amount of water discharge through all hydro power plants is less in comparison to case one to fulfill the same load demand, which shows the importance of CHPHs.     

Microstructural, photocatalysis and electrochemical investigations on CeTi2O6 thin films

The properties of sol–gel derived CeTi₂O₆ thin films deposited using a solution of cerium chloride heptahydrate and titanium propoxide in ethanol are discussed. The effect of annealing temperature on structural, optical, photoluminescence, photocatalysis and electrochemical characteristics has been examined. Lowest annealing temperature for the formation of crystalline CeTi₂O₆ phase in these samples is identified as 580 °C. The optical transmittance of the films is observed to be independent of the annealing temperature. The optical energy bandgap of the 600 °C annealed film for indirect transition is influenced by the presence of anatase phase of TiO₂ in its structure. Fourier transform infrared spectroscopy investigations have evidenced increased bond strength of the Ti–O–Ti network in the films as a function of annealing temperature. The photoluminescence intensity of the films has shown dependence on the annealing temperature with the films fired at 450 °C exhibiting the maximum photoluminescence activity. The decomposition of methyl orange and eosin (yellow) under UV–visible light irradiation in the presence of crystalline CeTi₂O₆ films shows the presence of photoactivity in these films. The photocatalytic response of CeTi₂O₆ films is found to be superior to the TiO₂ films. In comparison to crystalline films, the amorphous films have shown superior electrochemical characteristics. The 500 °C annealed amorphous films have exhibited the most appropriate properties for incorporation in electrochromic devices comprising tungsten oxide as the primary electrochromic electrode.