1,072 research outputs found

    Supersymmetric And Smooth Hybrid Inflation In The Light Of WMAP3

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    In their minimal form both supersymmetric and smooth hybrid inflation yield a scalar spectral index n_s close to 0.98, to be contrasted with the result n_s=0.951+0.015-0.019 from WMAP3. To realize better agreement, following hep-ph/0604198, we extend the parameter space of these models by employing a non-minimal Kaehler potential. We also discuss non-thermal leptogenesis by inflaton decay and obtain new bounds in these models on the reheat temperature to explain the observed baryon asymmetry.Comment: 21 pages, 12 figures, revtex4. v2: minor revisions, additional references, to appear in PR

    Effect of gibberrelic acid on á-amylase activity in heat stressed mung bean (Vigna radiata L.) seedlings

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    High temperature is a serious threat that can alter the number of biochemical processes in plants, which may lead to reduce crop yield. Gibberellic acid (GA3) is a plant growth hormone, responsible for growth, stress tolerance and regulation of many enzymes like amylase. Amylase is responsible for growth by hydrolyzing starch into maltose. This experiment was carried out to study the effect of GA3 on á-amylase activity under heat stress conditions of four genotypes of mung bean (NM 19-19, NM 20-21, NM 121-123 and NCM 89). Seeds were sown in Petri dishes and incubated at different temperatures with and without 100 µM GA3. It was found that the lethal temperature was 50°C when exposed for 2 h and reduced β-amylase activity in all genotypes which increased when a mild temperature (40°C,1 h) prior to lethal temperature was given. The application of GA3 can further alleviate the effect of heat stress by increasing β-amylase activity. Genotypic variations was also observed and activity of amylase and heat stress tolerance index was highest in NM 19-19 and lowest in NM 20-21 for all treatments.Key words: Mung bean, á-amylase, gibberellic acid, heat stress

    βC1 of chili leaf curl betasatellite is a pathogenicity determinant

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    <p/> <p>Background</p> <p>Cotton leaf curl disease in the Indian subcontinent is associated with several distinct begomoviruses that interact with a disease-specific DNA satellite named Cotton leaf curl Multan betasatellite (CLCuMB). However, we have recently reported that Chili leaf curl betasatellite (ChLCB) is also occasionally found associated with the disease in Pakistan. The question as to whether ChLCB contributes to the development of disease symptoms such as leaf curling and enations remain to be answered. We have previously shown that the expression of βC1 of CLCuMB develops all symptoms of cotton leaf curl disease in <it>Nicotiana benthamiana </it>when expressed from PVX vector.</p> <p>Findings</p> <p>The role of ChLCB in the induction of typical disease symptoms was studied by its expression from PVX vector in <it>N. benthamiana</it>. The expression of βC1 from PVX vector developed severe leaf curl symptoms and leaf-like enations that resemble the phenotype induced by βC1 of CLCuMB.</p> <p>Conclusions</p> <p>The results presented here show that the expression of βC1 of ChLCB from PVX vector exhibit phenotype typical of cotton leaf curl and therefore ChLCB may contribute to the disease symptoms.</p

    Influence of hyperhomocysteinemia on the cellular redox state - Impact on homocysteine-induced endothelial dysfunction

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    Hyperhomocysteinemia is an independent risk factor for the development of atherosclerosis. An increasing body of evidence has implicated oxidative stress as being contributory to homocysteines deleterious effects on the vasculature. Elevated levels of homocysteine may lead to increased generation of superoxide by a biochemical mechanism involving nitric oxide synthase, and, to a lesser extent, by an increase in the chemical oxidation of homocysteine and other aminothiols in the circulation. The resultant increase in superoxide levels is further amplified by homocysteinedependent alterations in the function of cellular antioxidant enzymes such as cellular glutathione peroxidase or extracellular superoxide dismutase. One direct clinical consequence of elevated vascular superoxide levels is the inactivation of the vasorelaxant messenger nitric oxide, leading to endothelial dysfunction. Scavenging of superoxide anion by either superoxide dismutase or 4,5-dihydroxybenzene 1,3-disulfonate (Tiron) reverses endothelial dysfunction in hyperhomocysteinemic animal models and in isolated aortic rings incubated with homocysteine. Similarly, homocysteineinduced endothelial dysfunction is also reversed by increasing the concentration of the endogenous antioxidant glutathione or overexpressing cellular glutathione peroxidase in animal models of mild hyperhomocysteinemia. Taken together, these findings strongly suggest that the adverse vascular effects of homocysteine are at least partly mediated by oxidative inactivation of nitric oxide

    Structure and Growth of Core–shell Nanoprecipitates in Al–Er–Sc–Zr–V–Si High-temperature Alloys

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    Lightweight Sc-containing aluminum alloys exhibit superior mechanical performance at high temperatures due to core–shell, L12-ordered trialuminide nanoprecipitates. In this study, the structure of these nanoprecipitates was studied, using different transmission electron microscopy (TEM) techniques, for an Al–Er– Sc–Zr–V–Si alloy that was subjected to a two-stage overaging heat treatment. Energy-dispersive X-ray spectroscopy of the spherical Al3(Sc, Zr, Er ,V) nanoprecipitates revealed a core–shell structure with an Sc- and Er-enriched core and a Zr-enriched shell, without a clear V outer shell. This structure is stable up to 72% of the absolute melting temperature of Al for extended periods of time. High-angle annular dark-field scanning TEM was used to image the {100} planes of the nanoprecipitates, demonstrating a homogeneous L12-ordered superlattice structure for the entire nanoprecipitates, despite the variations in the concentrations of solute atoms within the unit cells. A possible growth path and compositional trajectory for these nanoprecipitates was proposed using high-resolution TEM observations, where different rod-like structural defects were detected, which are considered to be precursors to the spherical L12-ordered nanoprecipitates. It is also hypothesized that the structural defects could consist of segregated Si; however, this was not possible to verify with HAADF-STEM because of the small differences in Al and Si atomic numbers. The results herein allow a better understanding of how the Al–Sc alloys’ core–shell nanoprecipitates form and evolve temporally, thereby providing a better physical picture for future atomistic structural mappings and simulations

    Quinidine-Induced Immune Thrombocytopenia

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    We have identified six cases of quinidine-induced immune thrombocytopenia based on clinical evidence and in association with elevated amounts of platelet surface IgG. The degree of thrombocytopenia did not correlate with severity of clinical symptoms, nor did it predict the amount of IgG on the platelet surface. Three of the patients recovered promptly after drug discontinuation alone whereas the other patients received additional corticosteroid therapy. The clinical presentation, mode of diagnosis, and therapeutic considerations in the treatment of drug-induced thrombocytopenia are discussed

    Synthesis, Characterization and DNA Cleavage of Copper(II) Complex with D,L-Dithiothreitol

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    Purpose: To study deoxyribonucleic acid (DNA) shearing capability of copper(II) complex of dithiothreitol (DTT) and to fevaluate its potential application in cancer therapy.Methods: A parrot green complex was synthesized by grinding copper acetate monohydrate and DTT in 1:2 molar ratio in a mortar until no fumes of acetic acid were observed. The complex was characterized using attenuated total reflectance-Fourier transform infra-red (ATR-FTIR), and x-ray diffraction (XRD) techniques. Further information was also collected through Karl Fischer titration, thermogravimetric analysis (TGA) and (magnetic moment. Cleavage of DNA was determined by agarose gel electrophoresis. The gel was then stained, analyzed and photographed under ultraviolet (UV) light.Results: ATR-FTIR confirmed the formation of copper(II) complex with DTT by binding through thiol group based on the disappearance of the thiol (-SH) stretching peak at 2545 cm-1. The crystalline structure was elucidated by a sharp intense peak at 38.520 in XRD spectrum while the octahedral geometry of complex was inferred from a magnetic moment of 1.72 B.M. The results for water content obtained by Karl Fischer titration and TGA revealed that water molecules are not part of the coordination sphere of the complex. Cleavage study of DNA showed that the complex completely sheared the circular DNA compared to pure DTT.Conclusion: Solvent free synthesis of Copper(II)-DTT complex has been successfully achieved, and an anhydrous complex with octahedral geometry obtained. The complex has a greater potential to shear DNA molecule than pure DTT.Keywords: DNA shearing, Copper(II) complex, Dithiothreitol, Attenuated total reflectance-Fourier transform infra-red, Karl Fischer titration, Magnetic momen

    Succinimide-N-sulfonic acid as an efficient recyclable catalyst for the synthesis of some fused indolo pyrano pyrimidinone derivatives

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    A new, simple, thermally efficient and solvent-free condensation of 2-amino-4,5-dihydro-4-phenylpyrano[3,2-b]indole-3-carbonitrile derivatives with coumarin-3-carboxylic acid employing succinimide-N-sulfonic acid (SuSA) as catalyst for the synthesis of a series of 5,6-dihydro-2-(2-oxo-2H-chromen-3-yl)-5-phenyl-indolo[2',3':5,6]pyrano[2,3-d]pyrimidin-4(3H)-one derivatives is described. This method has the advantages of high yield, simple methodology, and short reaction time, as well as being green in terms of avoiding the use of toxic catalysts and solvents. Furthermore, the catalyst could be recycled and reused four times without significant loss of activity. Thiourea dioxide (TUD) catalyzed efficient three-component coupling reactions of aromatic aldehydes, 3-hydroxyindole and malononitrile in water at 70 ºC was described as the preparation of 2-amino-4,5-dihydro-4-phenylpyrano[3,2-b]indole-3-carbonitrile derivatives. KEY WORDS: Succinimide-N-sulfonic acid, Thiourea dioxide, Coumarin-3-carboxylic acid, Indolo pyrano  pyrimidineone derivatives Bull. Chem. Soc. Ethiop. 2015, 29(3), 457-471.DOI: http://dx.doi.org/10.4314/bcse.v29i3.1
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