10 results on '"Shraddha Pai"'
Search Results
2. As (III) removal using superparamagnetic magnetite nanoparticles synthesized using Ulva prolifera − optimization, isotherm, kinetic and equilibrium studies
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Raja Selvaraj, Gokulakrishnan Murugesan, Gayathri Rangasamy, Ruchi Bhole, Niyam Dave, Shraddha Pai, Keshava Balakrishna, Ramesh Vinayagam, and Thivaharan Varadavenkatesan
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Environmental Engineering ,Plant Extracts ,Iron ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Hydrogen-Ion Concentration ,Pollution ,Ferrosoferric Oxide ,Oxygen ,Kinetics ,Ulva ,Metals, Heavy ,Environmental Chemistry ,Adsorption ,Magnetite Nanoparticles ,Water Pollutants, Chemical - Abstract
In this study, magnetite nanoparticles (MNPs) were synthesized using the seaweed - Ulva prolifera, an amply found marine source in the Western coastal regions of India. The surface and other properties of MNPs were characterized by many sophisticated methods. Spherical nanoclusters were observed in the FESEM image and iron and oxygen elements were seen in EDS results. XRD peaks were consistent with magnetite standards and MNPs had good crystallinity. FTIR portrayed the specific signals for MNPs and TGA profile ascertained the thermal stability. Magnetic saturation of 41.84 emu/g with negligible hysteresis loop substantiated the superparamagnetism. XPS pointed out the presence of Fe and O with oxidation states specific for MNPs, and the results were consistent with EDS. BET revealed a high specific surface area (144.98 m
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- 2022
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3. A recent update on green synthesized iron and iron oxide nanoparticles for environmental applications
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Raja Selvaraj, Shraddha Pai, Ramesh Vinayagam, Thivaharan Varadavenkatesan, Ponnusamy Senthil Kumar, Pham Anh Duc, and Gayathri Rangasamy
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Environmental Engineering ,Iron ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Nanoparticles ,Nanotechnology ,Environmental Chemistry ,Environmental Pollutants ,Magnetic Iron Oxide Nanoparticles ,Adsorption ,General Medicine ,General Chemistry ,Pollution - Abstract
Nanotechnology is considered the budding discipline in various fields of science and technology. In this review, the various synthesis methods of iron and iron oxide nanoparticles were summarised with more emphasis on green synthesis - a sustainable and eco-friendly method. The mechanism of green synthesis of these nanomaterials was reviewed in recent literature. The magnetic properties of these nanomaterials were briefed which makes them unique in the family of nanomaterials. An overview of various removal methods for the pollutants such as dye, heavy metals, and emerging contaminants using green synthesized iron and iron oxide nanoparticles is discussed. The mechanism of pollutant removal methods like Fenton-like degradation, photocatalytic degradation, and adsorption techniques was also detailed. The review is concluded with the challenges and possible future aspects of these nanomaterials for various environmental applications.
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- 2022
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4. Superparamagnetic hematite spheroids synthesis, characterization, and catalytic activity
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Ramesh Vinayagam, Yash Patnaik, P. Brijesh, Deepa Prabhu, Melisha Quadras, Shraddha Pai, Manoj Kumar Narasimhan, K. Kaviyarasu, Thivaharan Varadavenkatesan, and Raja Selvaraj
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Methylene Blue ,Environmental Engineering ,X-Ray Diffraction ,Health, Toxicology and Mutagenesis ,Spectroscopy, Fourier Transform Infrared ,Public Health, Environmental and Occupational Health ,Environmental Chemistry ,Magnetic Iron Oxide Nanoparticles ,General Medicine ,General Chemistry ,Pollution ,Ferric Compounds ,Catalysis - Abstract
The leaf extract of Muntingia calabura is being first reported to be used for the synthesis superparamagnetic hematite nanoparticles by following the green-chemistry approach. Field Emission - Scanning Electron Microscopic image revealed the formation of irregular nano spheroids averaging at 48.57 nm in size and characteristic of Fe and O atoms, as revealed by Energy Dispersive X-Ray spectrum. X-ray diffraction analysis results proved the crystallinity of hematite diffraction planes with crystallite sizes averaging at 30.68 nm. The lattice parameter values stayed concordant with the literature. The superparamagnetic nature was attested by the high value of saturation magnetism (2.20 emu/g) with negligible coercivity and retentivity. Fourier Transform Infrared Spectroscopy results affirmed numerous moieties involved in the synthesis of hematite nanoparticles and the existence of signature Fe-O bands. Thermogravimetric analysis studies portrayed the thermal behavior nanoparticles with 28% weight loss and thermal stability was attained after 700 °C. X-ray photoelectron spectroscopy analysis confirmed the valence states of Fe and O in the hematite nanoparticles and ascertained the purity. The mesoscopic structure was revealed by Brunauer-Emmett-Teller studies with considerable surface area (112.50 m
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- 2021
5. Adsorptive removal of Acid Blue 113 using hydroxyapatite nanoadsorbents synthesized using Peltophorum pterocarpum pod extract
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Hriday Sodhani, Shantanu Hedaoo, Gokulakrishnan Murugesan, Shraddha Pai, Ramesh Vinayagam, Thivaharan Varadavenkatesan, G. Bharath, Mohammad Abu Haija, Ashok Kumar Nadda, Muthusamy Govarthanan, and Raja Selvaraj
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Environmental Engineering ,Plant Extracts ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Hydrogen-Ion Concentration ,Pollution ,Kinetics ,Durapatite ,Environmental Chemistry ,Adsorption ,Azo Compounds ,Water Pollutants, Chemical - Abstract
The present work reports the study on the green synthesis of hydroxyapatite (HAP) nanoadsorbents using Peltophorum pterocarpum pod extract. HAP nanoadsorbents were characterized by using FESEM, EDS, TEM, XRD, FTIR, XPS, and BET analyses. The results highlighted the high purity, needle-like aggregations, and crystalline nature of the prepared HAP nanoadsorbents. The surface area was determined as 40.04 m
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- 2022
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6. Magnetic activated charcoal/Fe2O3 nanocomposite for the adsorptive removal of 2,4-Dichlorophenoxyacetic acid (2,4-D) from aqueous solutions: Synthesis, characterization, optimization, kinetic and isotherm studies
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Ramesh Vinayagam, Gokulakrishnan Murugesan, Raja Selvaraj, Selvaraju Narayanasamy, Thivaharan Varadavenkatesan, and Shraddha Pai
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Environmental Engineering ,Aqueous solution ,Nanocomposite ,Materials science ,Health, Toxicology and Mutagenesis ,Kinetics ,Public Health, Environmental and Occupational Health ,Langmuir adsorption model ,General Medicine ,General Chemistry ,Pollution ,symbols.namesake ,Adsorption ,Activated charcoal ,Chemical engineering ,symbols ,Environmental Chemistry ,Thermal stability ,Response surface methodology - Abstract
Magnetic activated charcoal/Fe2O3 nanocomposite (AC/Fe2O3NC) was fabricated using Spondias dulcis leaf extract by a facile method and used for the adsorptive removal of 2,4-Dichlorophenoxyacetic acid (2,4-D) from aqueous solutions for the first time. The nanocomposite was characterized by methods such as FE-SEM, EDS, XRD, FTIR, TGA, VSM, and BET to identify and confirm the surface morphology, elemental composition, crystalline nature, functional groups, thermal stability, magnetic behavior, and surface area respectively. Box-Behnken Design (BBD) – an optimization method, which belongs to the Response surface methodology (RSM) and a modeling tool – Artificial Neural Network (ANN) were employed to design, optimize and predict the relationship between the input parameters (pH, initial concentration of 2,4-D, time and agitation speed) versus the output parameter (adsorption efficiency of 2,4-D). Adsorption efficiency of 98.12% was obtained at optimum conditions (pH: 2.05, initial concentration: 32 ppm, contact time: 100 min, agitation speed: 130 rpm, temperature: 30 °C, and dosage: 0.2 g/L). The predictive ability of the ANN was superior (R2 = 0.99) than the quadratic model, given by the RSM (R2 = 0.93). The equilibrium data were best-fitted to Langmuir isotherm (R2 = 0.9944) and the kinetics obeyed pseudo-second-order model (R2 = 0.9993) satisfactorily. Thermodynamic studies revealed the spontaneity and exothermic nature of adsorption. The maximum adsorption capacity, qm was found to be 255.10 mg/g, substantially larger than the reported values for 2,4-D adsorption by other magnetic nanoadsorbents. Therefore, this nanoadsorbent may be utilized as an excellent alternative for the elimination of 2,4-D from the waterbodies.
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- 2022
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7. Structural characterization and adsorptive ability of green synthesized Fe3O4 nanoparticles to remove Acid blue 113 dye
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Arivalagan Pugazhendhi, Shraddha Pai, Manoj Kumar Narasimhan, Raja Selvaraj, and Srinivas M Kini
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Materials science ,General Physics and Astronomy ,Sorption ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Adsorption ,X-ray photoelectron spectroscopy ,Chemisorption ,Specific surface area ,Freundlich equation ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Mesoporous material ,Nuclear chemistry - Abstract
In the current study, Thunbergia grandiflora (Bengal clock vine) leaf extract has been used as green-resource to prepare Fe3O4 nanoparticles. SEM image showed agglomerated spherical (25 nm) particles, and EDS ascertained the existence of elemental iron (between 6 – 7 k eV) and oxygen (at 0.5 keV). XRD and XPS designated signature peaks for Fe3O4. BET studies revealed a high specific surface area of 114.42 m2/g with mesoporous structure. FTIR showed the distinct band for iron-oxide at 542 cm−1. A very low coercivity (1.5812 Oe) and retentivity (2.216 memu/g) indicated the paramagnetic properties of Fe3O4 nanoparticles. Batch adsorption of Acid blue 113 considering several factors conceded 95% removal within 3.5 h of contact time at pH 2 with the adsorbent dosage of 1 g/L, the concentration of 25 mg/L, 150 rpm, and the temperature of 303 K. The pseudo-second-order equation was best suited for the adsorption data indicating chemisorption. Freundlich isotherm model indicated a good fit for the equilibrium data. Thermodynamic parameters indicated exothermicity and spontaneity of the adsorption process. The maximum sorption capacity gained under an optimized environment was 138.89 mg/g. Hence, this study convincingly recognized the feasibility of the green synthesized Fe3O4 adsorbent for efficient Acid blue 113 dye removal with a suggestively greater sorption capacity.
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- 2021
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8. Structural characterization of green synthesized α-Fe2O3 nanoparticles using the leaf extract of Spondias dulcis
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Selvaraju Narayanasamy, Raja Selvaraj, Shraddha Pai, Ramesh Vinayagam, Manoj Kumar Narasimhan, and Thivaharan Varadavenkatesan
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Materials science ,Analytical chemistry ,General Physics and Astronomy ,Nanoparticle ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Microporous material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Absorption band ,Thermal stability ,Point of zero charge ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Superparamagnetism ,BET theory - Abstract
Microporous α-Fe2O3 nanoparticles were synthesized by employing the extract of Spondias dulcis leaves by green-synthesis technique for the first time. The nanoparticles were characterized by many techniques. A continual absorption band without any peak in UV-vis spectrum and a strong signal for iron and oxygen atoms in EDS confirmed the formation of iron-oxide nanoparticles. Rod-like structures with few aggregations due to magnetic interactions were witnessed in FE-SEM image. Specific peaks belonging to α-Fe2O3 nanoparticles were observed in XRD spectrum, and they were very pure and crystalline with a mean particle diameter of 11.38 nm. XPS analysis confirmed oxidation state of Fe and O and portrayed the presence of α-Fe2O3. A relatively higher surface area (190.84 m2/g) than reported green-synthesized α-Fe2O3 nanoparticles has been obtained by BET analysis, and the pores were microscopic (0.465 nm) in nature. Signature bands for Fe-O (1136 cm−1) and organic moieties stretching vibrations were confirmed by FTIR spectrum. The point of zero charge was determined as 7.97 which is concordant with the published value for α-Fe2O3. The thermal stability was ascertained by TGA which showed 28% weight loss. The synthesized α-Fe2O3 were superparamagnetic with a very high saturation magnetization value of 34.46 emu/g. Besides, a probable mechanism for the synthesis of microporous α-Fe2O3 has been proposed. Therefore, the highly pure, crystalline, and microporous α-Fe2O3 with high surface area, synthesized by this green synthesis method could play a significant role in various fields.
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- 2020
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9. Differential methylation of enhancer at IGF2 is associated with abnormal dopamine synthesis in major psychosis
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Lee Marshall, Bryan A. Killinger, Arturas Petronis, Viviane Labrie, Ji Liao, Piroska E. Szabó, Peipei Li, Shraddha Pai, and Peixin Jia
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Epigenomics ,Male ,Proteomics ,0301 basic medicine ,Genetics of the nervous system ,Bipolar Disorder ,Dopamine ,General Physics and Astronomy ,02 engineering and technology ,Epigenesis, Genetic ,Mice ,lcsh:Science ,Mice, Knockout ,Neurons ,Multidisciplinary ,Middle Aged ,021001 nanoscience & nanotechnology ,Cell biology ,Enhancer Elements, Genetic ,Schizophrenia ,DNA methylation ,Female ,0210 nano-technology ,medicine.drug ,Adult ,Psychosis ,Tyrosine 3-Monooxygenase ,Science ,Prefrontal Cortex ,Biology ,Chromatin structure ,Article ,General Biochemistry, Genetics and Molecular Biology ,Young Adult ,03 medical and health sciences ,Insulin-Like Growth Factor II ,medicine ,Animals ,Humans ,Epigenetics ,Enhancer ,Aged ,genetic-epigenetic interactions ,IGF2 ,epigenetic activation ,Tyrosine hydroxylase ,Gene Expression Profiling ,General Chemistry ,DNA Methylation ,medicine.disease ,Gene regulation ,Gene expression profiling ,030104 developmental biology ,lcsh:Q ,Transcriptome - Abstract
Impaired neuronal processes, including dopamine imbalance, are central to the pathogenesis of major psychosis, but the molecular origins are unclear. Here we perform a multi-omics study of neurons isolated from the prefrontal cortex in schizophrenia and bipolar disorder (n = 55 cases and 27 controls). DNA methylation, transcriptomic, and genetic-epigenetic interactions in major psychosis converged on pathways of neurodevelopment, synaptic activity, and immune functions. We observe prominent hypomethylation of an enhancer within the insulin-like growth factor 2 (IGF2) gene in major psychosis neurons. Chromatin conformation analysis revealed that this enhancer targets the nearby tyrosine hydroxylase (TH) gene responsible for dopamine synthesis. In patients, we find hypomethylation of the IGF2 enhancer is associated with increased TH protein levels. In mice, Igf2 enhancer deletion disrupts the levels of TH protein and striatal dopamine, and induces transcriptional and proteomic abnormalities affecting neuronal structure and signaling. Our data suggests that epigenetic activation of the enhancer at IGF2 may enhance dopamine synthesis associated with major psychosis., Dopamine dysregulation is centrally linked to major psychosis. Here, the authors characterise the hypomethylation of an enhancer within the insulin-like growth factor 2 gene in neurons of patients with major psychosis and provide evidence that this enhancer targets the tyrosine hydroxylase gene, responsible for dopamine synthesis.
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- 2019
10. DNA unmethylome profiling by covalent capture of CpG sites
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Artūras Petronis, Sun Chong Wang, Saulius Klimašauskas, Juozas Gordevičius, Audronė Lapinaitė, Ting Wang, Viviane Labrie, Shraddha Pai, Karolis Koncevičius, Carolyn Ptak, Edita Kriukienė, Giedrė Urbanavičiūtė, Tarang Khare, and Daofeng Li
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Male ,Biotin ,Prefrontal Cortex ,General Physics and Astronomy ,Genomics ,Computational biology ,Genome ,General Biochemistry, Genetics and Molecular Biology ,DNA sequencing ,Cell Line ,Epigenesis, Genetic ,Cytosine ,Humans ,DNA (Cytosine-5-)-Methyltransferases ,Epigenetics ,Promoter Regions, Genetic ,Oligonucleotide Array Sequence Analysis ,Genetics ,Multidisciplinary ,Genome, Human ,Chemistry ,High-Throughput Nucleotide Sequencing ,Sequence Analysis, DNA ,General Chemistry ,Epigenome ,DNA Methylation ,DNA Fingerprinting ,Spermatozoa ,CpG site ,DNA methylation ,CpG Islands ,DNA microarray - Abstract
Dynamic patterns of cytosine-5 methylation and successive hydroxylation are part of epigenetic regulation in eukaryotes, including humans, which contributes to normal phenotypic variation and disease risk. Here we present an approach for the mapping of unmodified regions of the genome, which we call the unmethylome. Our technique is based on DNA methyltransferase-directed transfer of activated groups and covalent biotin tagging of unmodified CpG sites followed by affinity enrichment and interrogation on tiling microarrays or next generation sequencing. Control experiments and pilot studies of human genomic DNA from cultured cells and tissues demonstrate that, along with providing a unique cross-section through the chemical landscape of the epigenome, the methyltransferase-directed transfer of activated groups-based approach offers high precision and robustness as compared with existing affinity-based techniques.
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- 2013
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