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Cu2O-Ag nanoheterostructure was synthesized by a simple and eco-friendly co-precipitation method, and its morphologic structure, linear and nonlinear optical properties were studied. Though pure Cu2O nano- and microparticles are known for their nonlinear absorption properties, current studies show that Ag nanoparticle in contact with Cu2O can significantly change the nonlinear response. When compared to pure Cu2O, our results indicate that Cu2O-Ag composite shows a saturable absorption behavior at lower excitation powers and flips to reverse saturable absorption at higher excitation powers. The composite also results in the bandgap modification and opens an extra window for two-photon absorption, while the excited state absorption was more probable in pure Cu2O. Interband transition occurs in Ag nanoparticle due to simultaneous two-photon absorption when excited by 532 nm. The excited carriers decay through nonradiative relaxation processes, leading to an increase in the nonlinear scattering mechanism, and the nonlinear scattering is found to increase with the excitation intensity. TEM data reveal the formation of spherical nanoheterostructure of Cu2O and Ag nanoparticles of ~ 30 nm diameter. XRD analysis provided further insight into the morphologic structure. [ABSTRACT FROM AUTHOR]

The present work deals with an inclined magnetohydrodynamic flow of a micropolar fluid occurring between two stretchable disks rotating co-axially at a constant distance apart by taking into account higher order chemical reaction effects. Using similarity variables the Navier–Stokes equations, which represent the momentum, microrotation, energy, and concentration, are transformed into ordinary differential equations. The transformed conservation equations are solved numerically by using the Nachtsheim–Swigert shooting iteration technique along with sixth-order Runge–Kutta integration scheme. The influence of governing parameters are shown graphically and discussed. It was observed that an increase in the aligned angle strengthens the applied magnetic field and decreases the momentum boundary layer profiles of the micropolar fluid flow. Heat transfer rate reduces for larger values of chemical reaction Cr for both n = 1 and n = 2. [ABSTRACT FROM AUTHOR]

Irula tribes in india live in rural areas under poor infrastructure, high poverty, low education, ignorant on the origin of diseases. Although, their lifestyle made them vulnerable to a variety of infectious diseases. Only few studies have been conducted on them, hence, there is inadequate data about these Irula tribal health. Serum samples were collected from 372 Participants of Irula tribes from 15 different locations of Tamil Nadu. Serum samples were tested for Hepatitis C Virus (Anti-HCV) by 3rd generation ELISA kit and data were subjected to analysis using SPSS (version 17.0) and Chi square test to determine the risk factors of Hepatitis C virus. HCV prevalence was 5.10 % and this percentage was high among females than males with the age group of 31 to 40. Among the various risk factors, were statistically analyzed (p<0.05) with HCV infection. The frequency of combination of risk factors were found in HJ+A+IDU+SI+M (100 %), A+IDU+SP (100 %) in Anti-HCV positive Irula tribes of Tamil Nadu. High prevalence of HCV infection was observed among the tribal population with the various risk factors such as series of injection, surgery with or without blood transfusion, tattooing sexual promiscuity, migration, jaundice in family and intravenous drug use. [ABSTRACT FROM AUTHOR]

An investigation has been carried out to study the effect of hydrodynamic boundary layer flow over an unsteady porous stretching surface in the presence of non-uniform heat source/sink. Heat transfer characteristics are examined for variable wall temperature and variable heat flux of boundary conditions. The governing equations are transformed to ordinary differential equations by similarity transformation and solved numerically by Runge-Kutta fourth order method in association with quasilinear shooting technique. The effects of unsteadiness parameter, permeability parameter, magnetic parameter, Prandtl number and heat source or sink parameter are represented graphically and discussed. [ABSTRACT FROM PUBLISHER]

The molecular binding orientation with respect to the electrode plays a pivotal role in determining the performance of molecular devices. However, accomplishing in situ modulation of single-molecule binding orientation remains a great challenge due to the lack of suitable testing systems and characterization approaches. To this end, by employing a developed STM-BJ technique, we demonstrate that the conductance of pyridine-anchored molecular junctions decreases as the applied voltage increases, which is determined by the repeated formation of thousands of gold-molecule-gold dynamic break junctions. In contrast, the static fixed molecular junctions (the distance between two electrodes is fixed) with identical molecules exhibit a reverse tendency as the bias voltage increases. Supported by flicker noise measurements and theoretical calculations, we provide compelling evidence that the orientation of nitrogen-gold bonds (a universal coordinate bond) in the pyridine-anchored molecular junctions can be manipulated to align with the electric field by the synergistic action of the mechanical stretching force and the electric fields, whereas either stimulus alone cannot achieve the same effect. Our study provides a framework for characterizing and regulating the orientation of a single coordinate bond, offering an approach to control electron transport through single molecular junctions., Competing Interests: The authors declare no competing financial interests., (This journal is © The Royal Society of Chemistry.)

We synthesis different sizes of cadmium selenide quantum dots (CdSe QDs) and their linear and nonlinear optical properties. Size-controlled CdSe QDs are characterized by ultraviolet-visible absorption, photoluminescence, transmission electron microscope (TEM), and Z-scan techniques. Redshift was observed in the linear absorption and photoluminescence with an increase in the size of CdSe QDs. TEM images show the sizes of the QDs are 2.2 nm-4.9 nm. Bandgap tuning CdSe QDs of third-order nonlinear optical properties are investigated at 532 nm with an open aperture Z-scan technique using a picosecond laser. These CdSe QDs can be used as optical limiters.

ZnO nanoparticles doped with transition metal (Ag, Ni, Mn) were prepared by using co-precipitation method. Absorption spectra showed exciton peak for ZnO nanoparticles at 367 nm and for Ag, Ni, Mn doped ZnO nanoparticles at 328, 354 nm and 342 nm respectively. Photoluminescence dynamics showed shallow level-trap and deep-level emission where the intensity of deep-level trap increases with transition metal doping due to the oxygen deficiency. Nonlinear absorption measurements showed the two-photon absorption increasing with transition metal following the trend Ag > Ni > Mn when excited with 532 nm, 30 ps laser pulses. The transition metal doped and un-doped ZnO nanoparticles can be used as optical limiters.

Terminalia catappa L. belonging to Combretaceae family is a folk medicine, known for its multiple pharmacological properties, but the neuro-modulatory effect of TC against chronic mild stress was seldom explored. The present study was designed to elucidate potential antidepressant-like effect of Terminalia cattapa (leaf) hydro-alcoholic extract (TC) by using CMS model for a period of 7 weeks. Identification of hydrolysable tannins was done by using LC-MS. After the CMS exposure, mice groups were administered with imipramine (IMP, 10mg/kg, i.p.) and TC (25, 50 and 100mg/kg of TC, p.o.). Behavioural paradigms used for the study included forced swimming test (FST), tail suspension test (TST) and sucrose preference test (SPT). After behavioural tests, monoamine neurotransmitter, cortisol, AchE, oxidative stress levels and mRNA expression studies relevant to depression were assessed. TC supplementation significantly reversed CMS induced immobility time in FST and other behavioural paradigms. Moreover, TC administration significantly restored CMS induced changes in concentrations of hippocampal neurotransmitters (5-HT, DA and NE) as well as levels of acetyl cholinesterase, cortisol, monoamine oxidases (MAO-A, MAO-B), BDNF, CREB, and p-CREB. It suggests that TC supplementation could supress stress induced depression by regulating monoamine neurotransmitters, CREB, BDNF, cortisol, AchE level as well as by amelioration of oxidative stress. Hence TC can be used as a complementary medicine against depression-like disorder., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)