Publications by authors named "Sivakumar S"

The effect of chloroform: methanolic (80:20) extract of C. asiatica (CA; 100 and 200 mg/kg), was evaluated on the course of free radical generation and excitotoxicity in monosodiumglutamate (MSG) treated female Sprague Dawley rats. The extract showed significant improvement in catalase, super oxide desmutase and lipid peroxides levels in hippocampus and striatum regions.

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Multinuclear solid-state NMR spectroscopy and powder X-ray diffraction (XRD) experiments are applied to comprehensively characterize a series of pure and lanthanide-doped LaF3 nanoparticles (NPs) that are capped with di-n-octadectyldithiophosphate ligands (Ln3+ = diamagnetic Y3+ and Sc3+ and paramagnetic Yb3+ ions), as well as correlated bulk microcrystalline materials (LaF3, YF3, and ScF3). Solid-state 139La and 19F NMR spectroscopy of bulk LaF3 and the LaF3 NPs reveal that the inorganic core of the NP retains the LaF3 structure at the molecular level; however, inhomogeneous broadening of the NMR powder patterns arises from distributions of 139La and 19F NMR interactions, confirming a gradual change in the La and F site environments from the NP core to the surface. 139La and 19F NMR experiments also indicate that low levels (5 and 10 mol %) of Ln3+ doping do not significantly change the LaF3 structure in the NP core.

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Aminopeptidase-N (APN) and cadherin proteins located at the midgut epithelium of Helicoverpa armigera have been implicated as receptors for the Cry1A subfamily of insecticidal proteins of Bacillus thuringiensis. Ligand blot analysis with heterologously expressed and purified H. armigera Bt receptor with three closely related Cry1A proteins tentatively identified HaAPN1 as an interacting ligand.

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Zeins are prolamin storage proteins that accumulate in kernel endosperm of several cereals. For cloning of genes coding for zein-like proteins that accumulate in enhanced quantities in the filling stages of little millet (Panicum sumatrense Roth.) developing grains, RT-PCR was performed using specific primers.

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A facile, convenient, efficient, and high yielding synthesis of a combinatorial library of 3-aroylcoumarins has been developed by the condensation of easily available alpha-aroylketene dithioacetals (AKDTAs) and 2-hydroxybenzaldehydes (salicylaldehydes)/2-hydroxy-1-naphthaldehyde in the presence of catalytic amount of piperidine in THF reflux. The condensation of ferrocene derived alpha-aroylketene dithioacetal and 2-hydroxybenzaldehyde furnished coumarin installed on a ferrocene platform.

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Insect viruses have evolved to counter physiological barriers to infection presented by the host insect. For the Lepidoptera (butterflies and moths), these barriers include (1) the peritrophic membrane (PM) lining the gut, which presents a physical barrier to virus infection of the midgut epithelial cells, (2) the basement membrane (BM) that overlies the gut thereby restricting secondary infection of other tissues, and (3) the immune system of the host insect. Hence, insect viruses provide a resource for genes that disrupt host physiology in a specific manner, and these genes in turn serve as a resource both for the study of physiological processes, and for disruption of these processes for pest management purposes.

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Background & Objective: Typhoid fever still continues to be a major public health problem around the world. A simple, reliable and affordable rapid diagnostic test has been a long felt need of the clinicians. We therefore prospectively evaluated the sensitivity and specificity of Typhidot test.

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The Cu accumulation capacity of stem cuttings of Portulaca oleracea was assessed in two different soils, alfisol and vertisol, which differ from each other mainly due to their clay content - several fold lower in the former than in the latter. The DTPA extractable concentration of Cu in soil and the level of its accumulation in stem cuttings were, therefore, greater in alfisol than in vertisol. In the mixed soils, the DTPA extractable as well as plant accumulated levels of Cu decreased with an increase in the proportion of vertisol.

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The stem cuttings of the terrestrial, ornamental plant, Portulaca oleracea, grew well in distilled water by producing adventitious roots and leaves. However, when exposed to various concentrations of sulfate and nitrate salts of copper resulted in a suppression of root growth, increase in initiation time of roots and sprouts and decay of stem cuttings from the cut open end, decrease in number of leaves with an increase in concentration of copper in the growth medium. Accumulation of copper increased with increasing concentrations of both copper sulfate and copper nitrate.

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The preparation of nearly monodisperse (40 nm), silica-coated LaF(3):Ln(3+) nanoparticles and their bioconjugation to FITC-avidin (FITC=fluorescein isothiocyanate) is described in this report. Doping of the LaF(3) core with selected luminescent Ln(3+) ions allows the particles to display a range of emission lines from the visible to the near-infrared region (lambda=450-1650 nm). First, the use of Tb(3+) and Eu(3+) ions resulted in green (lambda=541 nm) and red (lambda=591 and 612 nm) emissions, respectively, by energy downconversion processes.

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Cunninghamella bertholletiae, a rare causative agent of mycosis among immunocompromised patients has been reported with increased frequency from western countries in recent years. We report a case of C. bertholletiae pulmonary infection in a 42-year-old male patient who developed graft-vs.

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Several pests are capable of decreasing crop production causing severe economical and social losses. Aiming to find novel molecules that could impede the digestion process of different pests, a screening of alpha-amylase and trypsin-like proteinase inhibitors was carried out in Prosopis juliflora, showing the presence of both in dry seeds. Furthermore, a novel trypsin inhibitor, with molecular mass of 13,292 Da, was purified showing remarkable in vitro activity against T.

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Soil and plant samples (root and shoot) of Prosopis juliflora were collected in the vicinity of metal based foundry units in Coimbatore and assessed for their heavy metal content (Cu and Cd) to ascertain the use of P. juliflora as a green solution to decontaminate soils contaminated with Cu and Cd. The results showed that Cu and Cd content was much higher in plant components compared to their extractable level in the soil.

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The effects of Cr(III) and Cr(VI) on the survival, behavior, and morphology of the earthworm, Eisenia fetida, in water at pH 6, 7, and 8 and their toxicity in 10 different soils and an organic substrate have been assessed. A decrease in the pH of water resulted in increased toxicity of Cr to the earthworm. In water, both Cr species produced behavioral changes and morphological symptoms.

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The reaction of 1,1-di(methylsulfanyl)-2-nitroethylene, benzyl alcohols, and sodium hydride furnishes crystalline triarylmethyl ortho esters of nitroacetic acid.

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The separation of propylene-propane mixture is an energy intensive operation commercially practiced using cryogenic distillation. The separation by pressure swing adsorption has been studied as an alternative. A fixed-bed pressure swing adsorption yields the heavy component as a pure product.

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Combating heart disease is one of the challenging problems of biomedical science today. Towards this goal an indigenous preparation 'Trikatu' (a herbal combination containing Piper longum (fruit), Piper nigrum (fruit) and Zingiber officinale (rhizome) dry powder) was fed to normal and cholesterol fed male Rattus norvegicus to ascertain its efficacy as a hypolipidaemic agent. Its effects on body weight, blood and tissue (aortic, cardiac and hepatic) lipids--total, free and esterified cholesterol, low density lipoprotein(LDL) and high density lipoprotein(HDL) cholesterol, triglycerides and phospholipids--and the atherogenic index were measured.

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Aim: To describe lesions resembling optic disc duplication and highlight their unusual visual fields. The authors also report the first case of pseudo-duplication of the optic disc with overlying retinal nerve fibre layer.

Methods: Retrospective, non-comparative review of case notes.

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Aim: To establish the reliability, efficacy, and safety of disposable prism tonometry and validate its routine use for screening as well as monitoring of glaucoma.

Methodology: Intraocular pressure (IOP) of 400 eyes of 200 consecutive patients who attended the general ophthalmic clinic was checked with both the Goldmann applanation tonometer and a disposable tonometer prism by an experienced examiner after obtaining informed consent. The data were statistically analysed.

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A new, simple chiral HPLC method was developed for the enantiomeric separation of Levetiracetam, [(S)-alpha-ethyl-2-oxo-pyrrolidine acetamide], an antiepileptic drug in pharmaceutical formulations and in bulk materials. Enantiomeric separation was achieved on a chiralpak AD-H column using a mobile phase consisting of hexane and isopropanol in the ratio (90:10, v/v) at a flow rate of 1.0 ml/min.

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In vivo labeling of DNA with thymidine and thymidine analogs has long been a cornerstone of replication studies. Unfortunately, yeast lack a thymidine salvage pathway and thus do not incorporate exogenous thymidine. Specifically, yeast neither efficiently take up exogenous thymidine from their growth media nor phosphorylate it to thymidylate, the precursor of dTTP.

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