Showing papers by "Bharathiar University published in 2014"

Health benefits of finger millet (Eleusine coracana L.) polyphenols and dietary fiber: a review

Abstract: The growing public awareness of nutrition and health care research substantiates the potential of phytochemicals such as polyphenols and dietary fiber on their health beneficial properties. Hence, there is in need to identify newer sources of neutraceuticals and other natural and nutritional materials with the desirable functional characteristics. Finger millet (Eleusine coracana), one of the minor cereals, is known for several health benefits and some of the health benefits are attributed to its polyphenol and dietary fiber contents. It is an important staple food in India for people of low income groups. Nutritionally, its importance is well recognised because of its high content of calcium (0.38%), dietary fiber (18%) and phenolic compounds (0.3–3%). They are also recognized for their health beneficial effects, such as anti-diabetic, anti-tumerogenic, atherosclerogenic effects, antioxidant and antimicrobial properties. This review deals with the nature of polyphenols and dietary fiber of finger millet and their role with respect to the health benefits associated with millet.

Finite-time stability analysis of fractional-order complex-valued memristor-based neural networks with time delays

Abstract: In this paper, the problem of finite-time stability of fractional-order complex-valued memristor-based neural networks (NNs) with time delays is extensively investigated. We first initiate the fractional-order complex-valued memristor-based NNs with the Caputo fractional derivatives. Using the theory of fractional-order differential equations with discontinuous right-hand sides, Laplace transforms, Mittag-Leffler functions and generalized Gronwall inequality, some new sufficient conditions are derived to guarantee the finite-time stability of the considered fractional-order complex-valued memristor-based NNs. In addition, some sufficient conditions are also obtained for the asymptotical stability of fractional-order complex-valued memristor-based NNs. Finally, a numerical example is presented to demonstrate the effectiveness of our theoretical results.

Eco-friendly synthesis of activated carbon from dead mango leaves for the ultrahigh sensitive detection of toxic heavy metal ions and energy storage applications

Abstract: A novel spherical carbon nanoparticle decorated activated carbon (SNAC) material with a high surface area of about 1555 m2 g−1 is prepared from the dead mango leaves by an eco-friendly method for the detection of toxic heavy metal ions and energy storage applications. The limits of detection (LODs) for the determination of Cd(II), Pb(II), Cu(II), and Hg(II) ions at the SNAC-modified GCE are 24.4 × 10−9 M, 5.7 × 10−9 M, 23.2 × 10−9 M and 24.6 × 10−9 M, respectively. On the other hand, the obtained maximum specific capacitance for the single electrode from galvanostatic charge discharge is 478 F g−1 at 1 A g−1. The symmetric supercapacitor cell provides a higher specific capacitance (SC) of 55 F g−1 at 1 A g−1, and energy density of 10.75 W h kg−1 at a power density of 300 W kg−1.

The Internet of Things (IoT) Applications and Communication Enabling Technology Standards: An Overview

Abstract: The Internet of Things (IoT) is the most promising area which penetrates the advantages of Wireless Sensor and Actuator Networks (WSAN) and Pervasive Computing domains. Different applications of IoT have been developed and researchers of IoT well identified the opportunities, problems, challenges and the technology standards used in IoT such as Radio-Frequency IDentification (RFID) tags, sensors, actuators, mobile phones, etc. This paper is of two fold, the first fold covers the different applications that adopted smart technologies so far. The second fold of this paper presents the overview of the sensors and its standards.

Co-encapsulation of probiotics with prebiotics on alginate matrix and its effect on viability in simulated gastric environment

Abstract: Two potential probiotic strains namely Staphylococcus succinus (MAbB4) and Enterococcus fecium (FIdM3) selected from previous probiotic property studies were co-encapsulated with complementary prebiotics. Two different prebiotics selected by in vitro fermentation viz. sugarbeet and chicory were separately encapsulated with both the strains in 2 g/100 mL alginate and were tested for the efficiency in improving the viability compared to free cells under in vitro acidic conditions. Results indicated significant improvement (P

Multifunctional HER2-Antibody Conjugated Polymeric Nanocarrier-Based Drug Delivery System for Multi-Drug-Resistant Breast Cancer Therapy

Abstract: Nanotechnology-based medical approaches have made tremendous potential for enhancing the treatment efficacy with minimal doses of chemotherapeutic drugs against cancer. In this study, using tamoxifen (Tam), biodegradable antibody conjugated polymeric nanoparticles (NPs) was developed to achieve targeted delivery as well as sustained release of the drug against breast cancer cells. Poly(D,L-lactic-co-glycolic acid) (PLGA) NPs were stabilized by coating with poly(vinyl alcohol) (PVA), and copolymer polyvinyl-pyrrolidone (PVP) was used to conjugate herceptin (antibody) with PLGA NPs for promoting the site-specific intracellular delivery of Tam against HER2 receptor overexpressed breast cancer (MCF-7) cells. The Tam-loaded PVP-PLGA NPs and herceptin-conjugated Tam-loaded PVP-PLGA NPs were characterized in terms of morphology, size, surface charge, and structural chemistry by dynamic light scattering (DLS), Transmission electron microscopy (TEM), ζ potential analysis, 1H nuclear magnetic resonance (NMR), and Fourier transform infrared (FT-IR) spectroscopy. pH-based drug release property and the anticancer activity (in vitro and in vivo models) of the herceptin conjugated polymeric NPs were evaluated by flow cytometry and confocal image analysis. Besides, the extent of cellular uptake of drug via HER2 receptor-mediated endocytosis by herceptin-conjugated Tam-loaded PVP-PLGA NPs was examined. Furthermore, the possible signaling pathway of apoptotic induction in MCF-7 cells was explored by Western blotting, and it was demonstrated that drug-loaded PLGA NPs were capable of inducing apoptosis in a caspase-dependent manner. Hence, this nanocarrier drug delivery system (DDS) not only actively targets a multidrug-resistance (MDR) associated phenotype (HER2 receptor overexpression) but also improves therapeutic efficiency by enhancing the cancer cell targeted delivery and sustained release of therapeutic agents.

The preparation of MnFe2O4 decorated flexible graphene wrapped with PANI and its electrochemical performances for hybrid supercapacitors

Abstract: A modest, cost effective and eco-friendly method is employed for the preparation of MnFe2O4 nanocube decorated, flexible graphene sheets, followed by polyaniline (PANI) which is wrapped by an in situ chemical oxidative polymerization method. The formation of the hybrid composites and their individual constituents are realized through X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR) and Raman spectroscopy. The MnFe2O4 nanocube decorated flexible graphene and PANI wrapped composite is visualised through transmission electron microscopic (TEM) images. The decorated MnFe2O4 particles have sizes in the range of 75–100 nm. The capacitive properties of the ternary composite is investigated and it has the obtained specific capacitance of 338 F g−1 at 0.5 mA cm−2 in 1 M NaCl aqueous electrolyte, which is 10 times greater than the pristine MnFe2O4 (32 F g−1). Similarly, the fabricated hybrid supercapacitor (MGP‖AC) provides the specific capacitance of about 51.87 F g−1 at 5 mV s−1 and its energy density is 10.25 W h kg−1 at 10 mA cm−2. Thus the obtained significant properties of the ternary composite are due to the distinctive characteristics of the individual constituents which leads to enhanced electrochemical properties like reducing the internal resistance and diffusion path length via the synergistic effect.

Surface Morphology-Dependent Room-Temperature LaFeO3 Nanostructure Thin Films as Selective NO2 Gas Sensor Prepared by Radio Frequency Magnetron Sputtering

Abstract: In the present work, perovskite LaFeO3 thin films with unique morphology were obtained on silicon substrate using radio frequency magnetron sputtering technique. The effect of thickness and temperature on the morphological and structural properties of LaFeO3 films was systematically studied. The X-ray diffraction pattern explored the highly oriented orthorhombic perovskite phase of the prepared thin films along [121]. Electron micrograph images exposed the network and nanocube surface morphology of LaFeO3 thin films with average sizes of ∼90 and 70 nm, respectively. The developed LaFeO3 thin films not only possess unique morphology, but also influence the gas-sensing performance toward NO2. Among the two morphologies, nanocubes exhibited high sensitivity, good selectivity, fast response–recovery time, and excellent repeatability for 1 ppm level of NO2 gas at room temperature. The response time for nanocubes was 24–11 s with a recovery duration of 35–15 s less than the network structure. The sensitivity to...

Photocatalytic degradation of organic dyes under visible light irradiation by floral-like LaFeO3 nanostructures comprised of nanosheet petals

Abstract: A facile and cost-effective surfactant assisted hydrothermal technique was used to prepare functional floral-like LaFeO3 nanostructures comprised of nanosheets via a self-assembly process. Scanning electron microscopy images revealed the floral structure of LaFeO3 comprising of nanosheet petals. The petals of ∼15 nm thickness and ∼70–80 nm length observed from transmission electron microscopy self-assembled to form floral structures. X-ray powder diffraction, Fourier-transform infrared spectroscopy and thermal analysis techniques were utilized to determine the structural information and thermal stability. The structural characterization revealed the orthorhombic phase of the prepared LaFeO3 product with high purity even at a high temperature of 800 °C. The growth mechanism of LaFeO3 floral nanostructures has been proposed and the band gap energy was estimated to be 2.10 eV using UV-Vis diffuse reflectance spectroscopy. The Brunauer–Emmett–Teller specific surface area was found to be 90.25 m2 g−1. The visible light photocatalytic activities of LaFeO3 floral nanostructures exhibited higher photocatalytic efficiency compared to the bulk LaFeO3 samples for the degradation of rhodamine B (RhB) and methylene blue (MB). The degradation of MB was higher than RhB. The photocatalytic mechanism for the degradation of organic dye has also been proposed.

Neferine, an alkaloid from lotus seed embryo, inhibits human lung cancer cell growth by MAPK activation and cell cycle arrest

Abstract: Neferine is the major bisbenzylisoquinoline alkaloid isolated from the seed embryo of a traditional medicinal plant Nelumbo nucifera (Lotus). Epidemiological studies have revealed the therapeutic potential of lotus seed embryo. Although several mechanisms have been proposed, a clear anticancer action mechanism of neferine on lung cancer cells is still not known. Lung cancer is the most common cause of cancer death in the world, and the patients with advanced stage of nonsmall lung cancer require adjunct chemotherapy after surgical resection for the eradication of cancer cells. In this study, the effects of neferine were evaluated and characterized in A549 cells. Neferine induced apoptosis in a dose-dependent manner with the hypergeneration of reactive oxygen species, activation of MAPKs, lipid peroxidation, depletion of cellular antioxidant pool, loss of mitochondrial membrane potential, and intracellular calcium accumulation. Furthermore, neferine treatment leads to the inhibition of nuclear factor kappaB and Bcl2, upregulation of Bax and Bad, release of cytochrome C, activation of caspase cascade, and DNA fragmentation. In addition, neferine could induce p53 and its effector protein p21 and downregulation of cell cycle regulatory protein cyclin D1 thereby inducing G1 cell cycle arrest. These results suggest a novel function of neferine as an apoptosis inducer in lung cancer cells.

Synthesis and electrochemical performances of maricite-NaMPO4 (M = Ni, Co, Mn) electrodes for hybrid supercapacitors

Abstract: Sodium metal phosphates, NaMPO4 (M = Mn, Co and Ni) were successfully synthesized by a solution combustion synthesis (SCS) method using glycine-nitrate as a precursor. An XRD Rietveld refinement method revealed the crystal structure and lattice parameters of NaMPO4 (M = Mn, Co and Ni). For the first time, the crystal structure parameters of the orthorhombic NaNiPO4 maricite-type phase were evaluated. Similarly, it was identified that the NaCoPO4 and NaMnPO4 have high temperature hexagonal and maricite phases, respectively. The calculated BET specific surface areas (SBET) of NaMnPO4, NaCoPO4 and NaNiPO4 were 17.7, 22.6 and 18.7 m2 g−1, respectively. The NaMPO4 (M = Mn, Co and Ni) electrode exhibits good specific capacitance in 1 M NaOH electrolyte, when compared with 1 M Na2SO4, 1 M NaNO3 and 1 M NaCl. This difference in specific capacitance was analysed based on the influence of electrolyte anions (Cl−, SO42−, OH− and NO3−) and pH conditions of the electrolyte solution. Overall, maricite-NaNiPO4 nanoparticles provided a high specific capacitance of 368 F g−1 compared to NaMnPO4 (163 F g−1) and NaCoPO4 (249 F g−1) in 1 M NaOH electrolyte. Subsequently, a hybrid supercapacitor (AC‖NaNiPO4) was fabricated and it delivered a good specific capacitance and cyclic stability compared to the commercially available device.

Enhanced Room-Temperature Ferromagnetism on Co-Doped CeO2 Nanoparticles: Mechanism and Electronic and Optical Properties

Abstract: The present study reports the effect of Co doping on the structural, optical, magnetic, and electronic properties of CeO2 nanoparticles (NPs) synthesized by a simple low-temperature co-precipitation method. Co doping was introduced by adding CoCl3 with different mole percentages (0%, 2%, 4%, and 6%) to cerium nitrate, which resulted in room-temperature ferromagnetism (RTFM). TEM and XRD analysis showed that the Co-doped CeO2 NPs are monodispersed with face centered cubic structure. The 6% Co-doped CeO2 NPs showed a coercivity value of 155 Oe and saturation magnetization of 0.028 emu/g at room temperature. The electronic structures of the as-prepared CeO2 and Co-doped CeO2 NPs were investigated by X-ray absorption near-edge structure (XANES) spectroscopy. The XANES spectra at Ce M- and L-edges clearly indicated a decrease in the valency state of Ce ions from Ce4+ to Ce3+ upon Co doping. This causes redistribution of oxygen ions and Co–Co bonding. The XANES study revealed that Co doping plays a prominent ro...

Fused-thiophene based materials for organic photovoltaics and dye-sensitized solar cells

Abstract: Organic photovoltaics (OPVs) and dye-sensitized solar cells (DSSCs) have drawn great interest from both academics and industry, due to the possibility of low-cost conversion of photovoltaic energy at reasonable efficiencies. This review focuses on recent progress in molecular engineering and technological aspects of fused-thiophene-based organic dye molecules for applications in solar cells. Particular attention has been paid to the design principles and stability of these dye molecules, as well as on the effects of various electrolyte systems for DSSCs. Importantly, it has been found that incorporation of a fused-thiophene unit into the sensitizer has several advantages, such as red-shift of the intramolecular charge transfer band, tuning of the frontier molecular energy level, and improvements in both photovoltaic performance and stability. This work also examines the correlation between the physical properties and placement of fused-thiophene in the molecular structure with regard to their performance in OPVs and DSSCs.

Replacement of fishmeal with Spirulina platensis, Chlorella vulgaris and Azolla pinnata on non-enzymatic and enzymatic antioxidant activities of Macrobrachium rosenbergii

Abstract: The fishmeal replaced with Spirulina platensis, Chlorella vulgaris and Azolla pinnata and the formulated diet fed to Macrobrachium rosenbergii postlarvae to assess the enhancement ability of non-enzymatic antioxidants (vitamin C and E), enzymatic antioxidants (superoxide dismutase (SOD) and catalase (CAT)) and lipid peroxidation (LPx) were analysed. In the present study, the S. platensis, C. vulgaris and A. pinnata inclusion diet fed groups had significant (P < 0.05) improvement in the levels of vitamins C and E in the hepatopancreas and muscle tissue. Among all the diets, the replacement materials in 50% incorporated feed fed groups showed better performance when compared with the control group in non-enzymatic antioxidant activity. The 50% fishmeal replacement (best performance) diet fed groups taken for enzymatic antioxidant study, in SOD, CAT and LPx showed no significant increases when compared with the control group. Hence, the present results revealed that the formulated feed enhanced the vitamins C and E, the result of decreased level of enzymatic antioxidants (SOD, CAT and LPx) revealed that these feeds are non-toxic and do not produce any stress to postlarvae. These ingredients can be used as an alternative protein source for sustainable Macrobrachium culture.

Synthesis of ZnFe2O4 nanoparticles and their asymmetric configuration with Ni(OH)2 for a pseudocapacitor

Abstract: Nanosized zinc ferrite (ZnFe2O4) particles are prepared by a simple aspartic acid assisted combustion method at three different pH conditions. X-ray diffraction analysis (XRD) is used to identify the single phase formation of ZnFe2O4 and its crystal system. The particle size and shape are revealed through transmission electron microscopy (TEM) images and the particles are in the size range between 20–30 nm. The valence states of zinc, iron and oxygen are determined through X-ray photoelectron spectroscopy (XPS). The electrochemical performances of the individual electrodes and fabricated cells are studied using cyclic voltammetry (CV), galvanostatic charge–discharge analysis (GCD) and impedance spectroscopy (EIS) analysis. A maximum specific capacitance of 1235 F g−1 at 1 mA cm−2 is obtained for ZnFe2O4 prepared at pH 10. Furthermore an asymmetric supercapacitor (ASC) is fabricated using ZnFe2O4 as the negative electrode and Ni(OH)2 as the positive electrode. Interestingly, this assembled ASC delivers good energy and power densities of 33 W h kg−1 and 68 W kg−1, respectively.