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Patil H.P.,Pondicherry UniversityPuducherry | Raja V.,Pondicherry UniversityPuducherry
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

The purpose of this paper is to introduce the new family of H-graphs that generalizes the existing notions of trees, higher dimensional trees and k-ctrees. Further, we establish the characterizations of both the wheel-graphs G〈Wn〉 for n ≥ 6 and Tk-graphs for k ≥ 4, where Tk is not a star. Finally, we determine the conditions under which the Tk-graphs are split graphs and also propose some open problems for further research. © Springer International Publishing Switzerland 2016.

Anbazhagan R.,Pondicherry UniversityPuducherry | Rangaswamy N.,Pondicherry UniversityPuducherry
Advances in Intelligent Systems and Computing | Year: 2014

In this paper, the contention performance of message- and code-based initial ranging is investigated for two different scenarios or cases when idle mode is activated at the mobile stations (MSs). First scenario assumes a chosen set of MSs to follow mobility waypoint between the base stations (BSs), while other MSs remain stationary. Second scenario (worst case) presumes that all the MSs served by the BSs follow either mobility waypoint or random waypoint between the BSs. Under these scenarios, during periodic location update, MSs undergo contentionbased network re-entry process. When more than one MSs undergo location update, it causes high contention amid MSs. Hence, this paper investigates the contention performance of message- and code-based ranging during periodic network re-entry. Simulations validate that the MSs in worst-case scenario with code ranging perform better in terms of idle-mode energy consumption (57.97%) and percentage of time in idle mode (68.11%) than message ranging under Rayleigh fading channel. © Springer India 2014.

Mata R.,Pondicherry UniversityPuducherry | Nakkala J.R.,Pondicherry UniversityPuducherry | Sadras S.R.,Pondicherry UniversityPuducherry
Colloids and Surfaces B: Biointerfaces | Year: 2016

Green synthesized gold nanoparticles have received substantial attention owing to their biomedical applications, particularly in cancer therapy. Although anticancer activities of green synthesized gold nanoparticles have been reported earlier, the underlying mechanism behind their anticancer activity is still to be understood. The present study, describes the green synthesis of Abutilon indicum gold nanoparticles (AIGNPs) from Abutilon indicum leaf extract (AILE) and their cytotoxic mechanism in colon cancer cells. Dimensions of spherical shaped AIGNPs were found to be in the range of 1–20 nm as determined by TEM. GC–MS and FTIR analysis indicated the presence of polyphenolic groups in AILE, which might have been involved in the stabilization of AIGNPs. In vitro free radical scavenging analysis revealed the radical quenching activity of AIGNPs. Further, the AIGNPs exhibited cytotoxicity in HT-29 colon cancer cells with IC50 values of 210 and 180 μg/mL after 24 and 48 h. This was mediated through nuclear morphological changes and cell membrane damage as evidenced by acridine orange/ethidium bromide, propidium iodide and AnnexinV-Cy3 staining methods. Mechanism of the observed cytotoxicity of AIGNPs was explained on the basis of increased levels of reactive oxygen species and simultaneous reduction in cellular antioxidants, which might have caused mitochondrial membrane potential loss, DNA damage and G1/S phase cell cycle arrest. Expression of cleaved Caspase-9, Caspase-8, Caspase-3, Lamin A/C and PARP, provided the clues for the induction of intrinsic and extrinsic apoptosis pathways in AIGNPs treated HT-29 cells. The study provides a preliminary guidance towards the development of colon cancer therapy using green synthesized gold nanoparticles. © 2016 Elsevier B.V.

Manivannan V.,Pondicherry UniversityPuducherry | Padmanaban R.,Pondicherry UniversityPuducherry
Chemical Physics | Year: 2016

We investigate the initial state-selected dynamics of the title reaction on its ground (1 3A″) and first excited (1 3A′) triplet potential energy surfaces (PESs) by a time-dependent wavepacket propagation method, employing the ab initio analytical PESs developed by Gamallo et al. (2003). All partial wave contributions up to the total angular momentum J=140 are found to be necessary for the scattering of NO diatom in its vibrational and rotational ground state up to a collision energy ∼0.9 eV. The converged initial state-selected reaction attributes viz., reaction probabilities, integral cross sections and thermal rate constants are obtained within the centrifugal sudden (CS) approximation and the convergence of the results are carefully checked by varying all parameters used in the numerical calculations. The dynamical results are compared with the other reported theoretical and experimental findings. Investigation on the energy-resolved channel-specific reaction probabilities infers that the N2 formation channel is very much favorable than the N-exchange channel. The reaction proceeds via some metastable resonances, observed from the oscillatory probability curves, which is more in the latter channel compared to the former. The effect of rotational and vibrational excitations of the reagent (NO diatom) on the dynamics is examined. We also examine the effect of isotopic substitution of N-atom (14N by 15N) on the reaction dynamics. © 2016 Elsevier B.V.

Vendamani V.S.,University of Hyderabad | Vendamani V.S.,Pondicherry UniversityPuducherry | Pathak A.P.,University of Hyderabad | Nageswara Rao S.V.S.,University of Hyderabad
Optical Materials | Year: 2015

Blue luminescent silicon nanoparticles (Si NPs) have been synthesized by using free standing porous silicon (FS-pSi) layer as a seed material. Transmission electron microscopy measurements confirm the generation of spherical nanoparticles with average size of about ∼5 nm. The crystalline nature of Si NPs was confirmed by selective area electron diffraction. The observed asymmetry and shift of Raman peaks with respect to bulk silicon further confirm the successful generation of Si NPs. The observed photoluminescence (PL) (at ∼447 nm) and the chromaticity diagram fall in the blue region. It matches with energy bandgap of SiNPs (∼2.85 eV) estimated by UV-VIS-NIR spectroscopy. This is an easy and versatile approach for generating high densities of Si NPs for possible use in micro and optoelectronic applications. © 2015 Elsevier B.V. All rights reserved.

Sripan C.,Pondicherry UniversityPuducherry | Sripan C.,Indian Institute of Science | Ganesan R.,Indian Institute of Science | Naik R.,Utkal University | Viswanath A.K.,Pondicherry UniversityPuducherry
Optical Materials | Year: 2016

Stoichiometric adjusted Cu2Zn1.5Sn1.2Se4+x (CZTSe) alloys were successfully prepared by a thermal molten method. The pure phase was formed at x = 0.8 as confirmed by XRD and Raman spectroscopy. The bulk alloy was used for thin film coating by thermal evaporation method. The prepared films were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), and FT-IR spectroscopy. The XRD and Raman spectroscopy analysis revealed the formation of polycrystalline CZTSe thin films with tetragonal crystal structure after annealing of 450 °C. Diode characteristics were studied on the Mo/CZTSe/CdS sandwich geometry. The oxidation state of the selenized film was studied by XPS. The optical band gap of the CZTSe film was about 1.42 eV, which was varying with annealing and selenization condition. The carrier concentration, resistance and mobility of the selenized films were found to be 5.2 × 1015 cm−3, 2.2 KΩ/square and 5.5 cm2 V−1s−1 respectively and the conduction type was p-type. This study sheds light on the effect of annealing and selenization on various phases modifications and the light-harvesting capability of CZTSe solar cells. © 2016

Subash A.,Sri Ramachandra University | Veeraraghavan G.,Sri Ramachandra University | Sali V.K.,Pondicherry UniversityPuducherry | Bhardwaj M.,Pondicherry UniversityPuducherry | And 2 more authors.
Carbohydrate Polymers | Year: 2016

Turbinaria ornata, a commonly found marine brown algae along the Gulf of Mannar, Southeast coast of India was evaluated for its anti-inflammatory potential and the bioactive compound present in it was characterized. Cotton pellet induced granuloma model in rats was used to assess the anti-inflammatory potential of the aqueous extract of Turbinaria ornata (ATO) (30, 100 and 300 mg/kg, p.o) which was compared with dexamethasone (0.1 mg/kg, p.o) a standard anti-inflammatory agent. Granuloma weight, haematological parameters and plasma markers (LDH, GPT, and CRP) were estimated. Further, the levels of oxidative stress markers (SOD, GPx, GSH, LPO, and Nitrite) and inflammatory markers (Cathepsin D and MPO) in the hepatic tissue were measured. ATO decreased the granuloma weight dose dependently. ATO significantly reversed the levels of biochemical and inflammatory markers in comparison to the vehicle treated rats. The active constituent, fucoidan (sulphated polysaccharide) from the aqueous extract was fractionated and characterized using GCMS. The sulphated polysaccharide (TSP) from ATO confirms the presence of sulphates and sugars. The present findings suggest ATO to be a potent inhibitor of both proliferative and exudative phases of inflammation possibly mediated by the sulphated polysaccharides which might inhibit the action of COX-2 enzyme analogous to dexamethasone. © 2016 Elsevier Ltd

Gupta K.K.,Pondicherry UniversityPuducherry | Sethi G.,Pondicherry UniversityPuducherry | Jayaraman M.,Pondicherry UniversityPuducherry
Journal of Vector Borne Diseases | Year: 2016

Background & objectives: It is well reported that exhaled CO2 and skin odour from human being assist female mosquitoes to locate human host. Basically, the receptors for this activity are expressed in cpA neurons. In both Aedes aegypti and Anopheles gambiae, this CO2-sensitive olfactory neuron detects myriad number of chemicals present in human skin. Therefore, manipulation of gustatory receptors housing these neurons may serve as important targets for behavioural intervention. The study was aimed towards virtual screening of small molecules in the analyzed conserved active site residues of gustatory receptor and molecular dynamics simulation study of optimum protein-ligand complex to identify a suitable lead molecule for distracting host-seeking behaviour of mosquitoes. Methods: The conserved residue analysis of gustatory receptor (GR) of Ae. aegypti and An. gambiae was performed. The structure of GR protein from Ae. aegypti was modeled and validated, and then molecular docking was performed to screen 2903 small molecules against the predicted active residues of GR. Further, simulation studies were also carried out to prove protein-ligand stability. Results: The glutamine 154 residue of GR was found to be highly conserved in Ae. aegypti and An. gambiae. Docking results indicated that the dodecanoic acid, 1,2,3-propanetriyl ester (dynasan 112) was interacting with this residue, as it showed better LibDock score than previously reported ethyl acetate used as mosquito repellant. Simulation studies indicated the structural instability of GR protein in docked form with dynasan 112 suggesting its involvement in structural changes. Based on the interaction energies and stability, this compound has been proposed to be used in mosquitoes’ repellant. Interpretation & conclusion: A novel effective odorant acting as inhibitor of GR is proposed based on its stability, docking score, interactions and RMSD, considering ethyl pyruvate as a standard inhibitor. Host preference and host-seeking ability of mosquito vectors play key roles in disease transmission, a clear understanding of these aspects is essential for preventing the spread of the disease. © 2016, Malaria Research Center. All rights reserved.

Ganaie S.U.,Pondicherry UniversityPuducherry | Abbasi T.,Pondicherry UniversityPuducherry | Abbasi T.,Worcester Polytechnic Institute | Abbasi S.A.,Pondicherry UniversityPuducherry
Journal of Experimental Nanoscience | Year: 2016

We demonstrate a simple, straightforward, clean-green, single pot approach for the synthesis of bimetallic Ag/Au nanoparticles (BNPs) by using a highly invasive terrestrial weed coral vine (Antigonon leptopus). Aqueous extracts of the weed were found to reduce the metal ions to form nanosised aggregates and then stabilise them by preventing further aggregation. The efficacy of the extracts of all its parts was explored by varying the stoichiometry of reactants, temperature, pH and reaction time. The electron micrographs of the synthesised BNPs indicated the presence of particles of predominantly spherical shapes in sizes ranging from 10 to 60 nm. The presence of gold and silver atoms was confirmed from the energy dispersive X-ray, X-ray photoelectron and X-ray diffraction studies. The Fourier transform infra-red spectroscopic spectral study indicated that the phenolics (including flavonoids) and proteins contained in the plant extract could have been responsible for the formation and stabilisation of the BNPs. © 2015 Taylor & Francis.

ABSTRACT: Traditionally Piper betle L. leaves have been used in India for fermenting certain foods. In our previous study, while fermenting Uttapam batter along with Piper betle L. var. Pachaikodi leaves led to suppression of gas formation and altered Lactic acid bacteria profile, especially in bacilli isolates compared to those observed in plain Uttapam batter fermentation. Hence, the aim of the present study was to understand the rationale behind these changes through characterization of Lactobacillus isolates from Piper betle L. var. Pachaikodi and also the leaves extracts for antimicrobial activity. Out of 72 isolates obtained from the betel leaves, only 10 isolates were bacilli which were chosen for their molecular characterization and to elucidate their inhibitory effects against major food borne pathogens and gas-forming bacteria and to compare with the effect of betel leaves extract. Random amplified polymorphic DNA (RAPD)-PCR and phenotype analysis was used to differentiate the isolates at strain level, 16S rRNA gene sequence for phylogenetic analysis and species-specific multiplex PCR analysis for sub-species identification. All isolates were identified as Lactobacillus plantarum subsp. plantarum. All Lactobacillus isolates were indigenous to leaf as they were resistant to betel leaves extract and showed maximum activity against some LAB and non-LAB indicator strains except Lactobacillus plantarum MTCC 6160 which was resistant. Among them, KJB23, 36 and 47 were the most effective. Particularly, the isolate KJB23 and ethanolic betal leaf extract showed rivaling inhibitory activity against major food borne pathogens, while dissimilar activity against gas forming bacteria. This study revealed that either Piper betle L. leaf or Lactobacillus strains from the leaves can be valuable for food applications when added to fermented products. © 2016 Taylor & Francis.

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