2,198 research outputs found

    To study the oxidative stress induced by lindane in epileptic rats brains and their modulation by neurosteroids

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    Background: Lindane is pesticide has been shown to affect the nervous system adversely. Previous work has shown that lindane is proconvulsant and neurosteroids (NS) has been shown to be neuroprotective against lindane-induced convulsions. As the mechanisms of lindane in epileptogenesis is not completely understood. The present study was designed to investigate the oxidative stress parameters of lindane toxicity in epileptogenesis and their modulation by NS like allopregnanolone (AP), and 4ʹ-chlorodiazepam (4ʹ-CD) in pentylenetetrazole (PTZ) kindling methods.Methods: Kindling was induced by injecting PTZ (30 mg/kg; s.c.) on alternate days i.e., 3 times in a week. Lindane was also administered (15 mg/kg p.o) on alternate days for 6 weeks. AP (2.5 mg/kg, intaperitoneal [i.p.]) and 4ʹ-CD (0.5 mg/kg, i.p.) single dose was given in kindled rats before lindane.Results: Following per oral administration of lindane for 6 weeks produced significant oxidative stress in epileptic brain. There was an increase in brain malondialdehyde (MDA) level and decrease in reduced glutathione (GSH) levels. AP (2.5 mg/kg, i.p.) and 4ʹ-CD (0.5 mg/kg, i.p.) single dose administration were not able to reverse the effect of chronic exposure of lindane.Conclusion: The result of the present study provides evidence that oxidative stress produced in the brain after chronic exposure of lindane may be the mechanism of epileptogenesis. Though NS have been shown to be neuroprotective, but they failed to reverse chronic oxidative stress produced by lindane. Further studies are required to demonstrate interaction of NS with lindane in oxidative stress

    Multispectral Classification With Bias-Tunable Quantum Dots-in-a-Well Focal Plane Arrays

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    Mid-wave and long-wave infrared (IR) quantum-dots-in-a-well (DWELL) focal plane arrays (FPAs) are promising technology for multispectral (MS) imaging and sensing. The DWELL structure design provides the detector with a unique property that allows the spectral response of the detector to be continuously, albeit coarsely, tuned with the applied bias. In this paper, a MS classification capability of the DWELL FPA is demonstrated. The approach is based upon: 1) imaging an object repeatedly using a sequence of bias voltages in the tuning range of the FPA and then 2) applying a classification algorithm to the totality of readouts, over multiple biases, at each pixel to identify the “class” of the material. The approach is validated for two classification problems: separation among different combinations of three IR filters and discrimination between rocks. This work is the first demonstration of the MS classification capability of the DWELL FPA

    Development of IPM Package with Safe Pesticide Residue: 1. Cabbage

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    An IPM module with safe pesticide residues on cabbage, with already proven treatments such as carbosulfan, dimethoate, cypermethrin + profenofos and mancozeb under chemical method of control; NSP, Bacillus thuringiensis and Trichogramma bactrae under non chemical method of control were revalidated individually and in combination. Six releases of parasitoid T. bactrae at weekly intervals starting from 12 days after transplanting or spray of NSP 4% at 10-15 days interval, 4 times, starting from 20 days after transplanting, foliar spray of dimethoate and mancozeb gave good control of aphids, leaf blight and black rot respectively. Based on the effectiveness of the treatment and pesticide residues below their permissible levels in cabbage at harvest, a module was developed and tested in the field. The IPM package thus developed was found to control the pests effectively and at the same time the residues on the crop were within the safe limits

    Voltammetric investigations of functional dyspepsia drug acotiamide at pencil graphite electrode: An eco-friendly and cost effective stripping detection method

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    First time, the electro-oxidative behaviour and determination of acotiamide at a pencil graphite electrode have been investigated under different experimental conditions using cyclic voltammetry (CV), differential pulse anodic stripping voltammetry (DPASV), and square wave anodic stripping voltammetric (SWASV) techniques. The voltammetric responses of acotiamide have been analyzed at different scan rates, pH and concentrations. Oxidation of acotiamide at the surface of pencil graphite electrode gave two well defined irreversible peaks in the voltammograms in BR buffer of pH 7.0. The oxidation process is completely diffusion controlled. A linear response of peak current has been obtained between 15.5 to 124 μM in non-aqueous media for all the voltammetric techniques. The proposed DPASV and SWASV techniques show limit of detection at 18.58 and 13.36 μM, respectively

    Plasmon assisted photonic crystal quantum dot sensors

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    We report Quantum Dot Infrared Detectors (QDIP) where light coupling to the self assembled quantum dots is achieved through plasmons occurring at the metal-semiconductor interface. The detector structure consists of an asymmetric InAs/InGaAs/GaAs dots-in-a-well (DWELL) structure and a thick layer of GaAs sandwiched between two highly doped n-GaAs contact layers, grown on a semi-insulating GaAs substrate. The aperture of the detector is covered with a thin metallic layer which along with the dielectric layer confines light in the vertical direction. Sub-wavelength two-dimensional periodic patterns etched in the metallic layer covering the aperture of the detector and the active region creates a micro-cavity that concentrate light in the active region leading to intersubband transitions between states in the dot and the ones in the well. The sidewalls of the detector were also covered with metal to ensure that there is no leakage of light into the active region other than through the metal covered aperture. An enhanced spectral response when compared to the normal DWELL detector is obtained despite the absence of any aperture in the detector. The spectral response measurements show that the Long Wave InfraRed (LWIR) region is enhanced when compared to the Mid Wave InfraRed (MWIR) region. This may be due to coupling of light into the active region by plasmons that are excited at the metal-semiconductor interface. The patterned metal-dielectric layers act as an optical resonator thereby enhancing the coupling efficiency of light into the active region at the specified frequency. The concept of plasmon-assisted coupling is in principle technology agnostic and can be easily integrated into present day infrared sensors

    The rigidity of crystalline color superconducting quark matter

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    We calculate the shear modulus of crystalline color superconducting quark matter, showing that this phase of dense, but not asymptotically dense, three-flavor quark matter responds to shear stress like a very rigid solid. To evaluate the shear modulus, we derive the low energy effective Lagrangian that describes the phonons that originate from the spontaneous breaking of translation invariance by the spatial modulation of the gap parameter Δ\Delta. These massless bosons describe space- and time-dependent fluctuations of the crystal structure and are analogous to the phonons in ordinary crystals. The coefficients of the spatial derivative terms of the phonon effective Lagrangian are related to the elastic moduli of the crystal; the coefficients that encode the linear response of the crystal to a shearing stress define the shear modulus. We analyze the two particular crystal structures which are energetically favored over a wide range of densities, in each case evaluating the phonon effective action and the shear modulus up to order Δ2\Delta^2 in a Ginzburg-Landau expansion, finding shear moduli which are 20 to 1000 times larger than those of neutron star crusts. The crystalline color superconducting phase has long been known to be a superfluid -- by picking a phase its order parameter breaks the quark-number U(1)BU(1)_B symmetry spontaneously. Our results demonstrate that this superfluid phase of matter is at the same time a rigid solid. We close with a rough estimate of the pinning force on the rotational vortices which would be formed embedded within this rigid superfluid upon rotation. Our results raise the possibility that (some) pulsar glitches could originate within a quark matter core deep within a neutron star.Comment: 38 pages, 5 figures. v3. Two new paragraphs in Section V (Conclusion); some additional small changes. A paragraph discussing supercurrents added in Section I (Introduction). Version to appear in Phys. Rev.
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