11 research outputs found

    Green Synthesis of High Temperature Stable Anatase Titanium Dioxide Nanoparticles Using Gum Kondagogu: Characterization and Solar Driven Photocatalytic Degradation of Organic Dye

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    The present study reports a green and sustainable method for the synthesis of titanium dioxide (TiO2) nanoparticles (NPs) from titanium oxysulfate solution using Kondagogu gum (Cochlospermum gossypium), a carbohydrate polymer, as the NPs formation agent. The synthesized TiO2 NPs were categorized by techniques such as X-Ray Diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy analysis, Raman spectroscopy, scanning electron microscope- Energy-dispersive X-ray spectroscopy (SEM-EDX), Transmission electron microscopy (TEM), High-resolution transmission electron microscopy (HR-TEM), UV-visible spectroscopy, Brunauer-Emmett-Teller (BET) surface area and particle size analysis. Additionally, the photocatalytic actions of TiO2 NPs were assessed with regard to their ability to degrade an organic dye (methylene blue) from aqueous solution in the presence of solar light. Various parameters affecting the photocatalytic activity of the TiO2 NPs were examined, including catalyst loading, reaction time, pH value and calcination temperature of the aforementioned particles. This green synthesis method involving TiO2 NPs explores the advantages of inexpensive and non-toxic precursors, the TiO2 NPs themselves exhibiting excellent photocatalytic activity against dye molecules

    Calcium and copper transport ATPases: analogies and diversities in transduction and signaling mechanisms

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    The calcium transport ATPase and the copper transport ATPase are members of the P-ATPase family and retain an analogous catalytic mechanism for ATP utilization, including intermediate phosphoryl transfer to a conserved aspartyl residue, vectorial displacement of bound cation, and final hydrolytic cleavage of Pi. Both ATPases undergo protein conformational changes concomitant with catalytic events. Yet, the two ATPases are prototypes of different features with regard to transduction and signaling mechanisms. The calcium ATPase resides stably on membranes delimiting cellular compartments, acquires free Ca2+ with high affinity on one side of the membrane, and releases the bound Ca2+ on the other side of the membrane to yield a high free Ca2+ gradient. These features are a basic requirement for cellular Ca2+ signaling mechanisms. On the other hand, the copper ATPase acquires copper through exchange with donor proteins, and undergoes intracellular trafficking to deliver copper to acceptor proteins. In addition to the cation transport site and the conserved aspartate undergoing catalytic phosphorylation, the copper ATPase has copper binding regulatory sites on a unique N-terminal protein extension, and has also serine residues undergoing kinase assisted phosphorylation. These additional features are involved in the mechanism of copper ATPase intracellular trafficking which is required to deliver copper to plasma membranes for extrusion, and to the trans-Golgi network for incorporation into metalloproteins. Isoform specific glyocosylation contributes to stabilization of ATP7A copper ATPase in plasma membranes

    Genomic analysis of early SARS-CoV-2 breakthrough infections from the state of Kerala suggest a preponderance of variants of concern

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    The SARS-CoV-2 Variant of Concern, Delta (B.1.617.2) was first reported in December 2020 in India and has spread colossally throughout the globe. Owing to factors like increased transmissibility, immune escape, and virulence, the delta variant has been considered as a potential public health threat apart from other variants of concern like alpha, beta and gamma. Kerala was one of the first states in India to enroll in the systematic genomic surveillance. In the present report, vaccine breakthrough infections were followed up in 147 patients including 55 healthcare workers who had been vaccinated with ChAdOx1 nCoV- 19/BBV152 across eleven districts from the state of Kerala. The timeline of samples analysed were from April 2021 till June 2021. Severity of the infections reported in the enrolled patients found to be mildly symptomatic, majorly with only 0.7% (n=1) of the cohort to be asymptomatic. Genomic analysis of the samples revealed the Delta variant (B.1.617.2) to constitute about 81.6% (n=120) in the studied cohort. This was followed by the Kappa variant B.1.617.1 (8.35%, n=9), AY.1 (0.6%, n= 1), AY.12 (0.6%, n= 1), AY.4 (1.2%, n= 2), AY.9 (1.2%, n= 2) and Eta variant, B.1.525 (0.6%, n= 1). 11 samples were not assigned any lineage. Evidence from this study suggests the preponderance of the Delta variant in the samples analysed
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