Physical and chemical techniques for a comprehensive characterization of river sediment: A case of study, the Moquegua River, Peru

River sediment is comprised of complex mineral systems composed by different kinds of organic and inorganic matter, and thus, is difficult to characterize. Besides, some standard techniques, such as X-ray diffraction (XRD), energy dispersive X-ray (EDX), optical and scanning electron microscopy, Fourier transmission infrared spectroscopy, inductively couple plasma-mass spectrometry (ICP-MS), and simultaneous Thermogravimetric Analysis – Differential Thermal Analysis (TGA-DTA), Mössbauer spectroscopy and magnetometry can provide substancial information about the compositional, physical, and chemical characteristics. In the current study, the versality of these methods is tested and the information provided by these methods for eight sediment samples, collected from the Moquegua River, Peru is compared. Qualitative analysis indicates that the samples consist of sand grains with different shapes, sizes, and colors coexisting with the presence of some diatoms. The chemical and mineralogical analysis reveal that the samples are composed mainly of silicon (Si), aluminium (Al), sodium (Na), potassium (K), aluminon–silicates, and carbonates, typical for river sediment. More detailed information obtained by these techniques include the discovery of adsorbed oxygen–hydrogen (O–H), carbon–H (C–H) and C, from organic matter, the thermal reactions and decomposition of the components, and the identification of the minor iron–oxides components. Further, other properties such as magnetic interaction are also analyzed in detail

Animal model integration to AutDB, a genetic database for autism

<p>Abstract</p> <p>Background</p> <p>In the post-genomic era, multi-faceted research on complex disorders such as autism has generated diverse types of molecular information related to its pathogenesis. The rapid accumulation of putative candidate genes/loci for Autism Spectrum Disorders (ASD) and ASD-related animal models poses a major challenge for systematic analysis of their content. We previously created the Autism Database (AutDB) to provide a publicly available web portal for ongoing collection, manual annotation, and visualization of genes linked to ASD. Here, we describe the design, development, and integration of a new module within AutDB for ongoing collection and comprehensive cataloguing of ASD-related animal models.</p> <p>Description</p> <p>As with the original AutDB, all data is extracted from published, peer-reviewed scientific literature. Animal models are annotated with a new standardized vocabulary of phenotypic terms developed by our researchers which is designed to reflect the diverse clinical manifestations of ASD. The new Animal Model module is seamlessly integrated to AutDB for dissemination of diverse information related to ASD. Animal model entries within the new module are linked to corresponding candidate genes in the original "Human Gene" module of the resource, thereby allowing for cross-modal navigation between gene models and human gene studies. Although the current release of the Animal Model module is restricted to mouse models, it was designed with an expandable framework which can easily incorporate additional species and non-genetic etiological models of autism in the future.</p> <p>Conclusions</p> <p>Importantly, this modular ASD database provides a platform from which data mining, bioinformatics, and/or computational biology strategies may be adopted to develop predictive disease models that may offer further insights into the molecular underpinnings of this disorder. It also serves as a general model for disease-driven databases curating phenotypic characteristics of corresponding animal models.</p

Green synthesis and characterization of silver nanoparticles using Boerhaavia diffusa plant extract and their anti bacterial activity

Green synthesis of silver nanoparticles was carried out using Boerhaavia diffuse plant extract as a reducing agent. The biosynthesized AgNPs were characterized by SEM-EDAX, XRD, TEM, UV-Vis, and FT-IR spectroscopy techniques. UV-Vis spectroscopy of prepared silver colloidal solution showed absorption maxima at 418 nm. XRD and TEM analysis revealed that AgNPs are face-centered, cubic structure being spherical in shape with an average particle size of 25 nm. The AgNPs were tested for antibacterial activity against three fish bacterial pathogens viz., Aeromonas hydrophila, Pseudomonas fluorescens and Flavobacterium branchiophilum and they demonstrated highest sensitivity toward F. branchiophilum when compared to other two bacterial pathogens. (C) 2013 Elsevier B.V. All rights reserved

Green Synthesis of Copper Oxide Nanoparticles Using Aloe vera Leaf Extract and Its Antibacterial Activity Against Fish Bacterial Pathogens

The present study reports biologically oriented process for green synthesis of CuO nanoparticles by using ecofriendly and non-toxic Aloe vera leaf extract. Powder X-ray diffraction and transmission electron microscope analysis revealed that synthesized CuO nanoparticles are in monoclinic phase with average particle size of 20 nm. The antibacterial activity of green synthesized CuO nanoparticles was tested against three bacterial fish pathogens "viz" Aeromonas hydrophila, Pseudomonas fluorescens and Flavobacterium branchiophilum, which are responsible for causing severe infectious diseases in fishes. CuO NPs exhibits enhanced antibacterial activity against all the fish pathogens even at lower concentrations, i.e. above 20 mu g/mL

Magnetic nanoparticle decorated graphene based electrochemical nanobiosensor for H2O2 sensing using HRP

To utilize synergetic effect of graphene's higher conductivity and magnetic nanoparticles biocompatibility, an electrochemical nanobiosensor is constructed based on magnetic nanoparticle decorated graphene (MRGO) using Horseradish peroxidase (HRP) for H2O2 sensing. Sensors based on magnetic nanoparticles (MNP) and reduced graphene oxide (RGO) are studied for comparison. MNP, RGO and MRGO were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). XRD studies have confirmed successful synthesis of Fe3O4 MNPs, RGO and MRGO. TEM micrographs revealed uniform decoration of MNPs on graphene. FTIR confirmed the immobilization of HRP on MNP, RGO and MRGO. The MRGO based sensor exhibited higher sensitivity (48.08 mu A mu M-1 cm(-2)) compared to MNP (39.08 mu A mu M-1 cm(-2)) and RGO (41.08 mu A mu M-1 cm(-2)) based biosensors. (C) 2018 Elsevier B.V. All rights reserved

Electrocatalytic activity of Cu2O nanocubes-based electrode for glucose oxidation

A direct electrocatalytic activity of glucose oxidation on cuprous oxide modified glassy carbon electrode is reported. Cu2O nanocubes were synthesized by a simple wet chemical route in the absence of surfactants. Purity, shape and morphology of Cu2O are characterized by XRD, SEM, XPS and DRS-UV. The Cu2O nanocubes-modified glassy carbon electrode (GCE) exhibited high electrocatalytic activity towards glucose oxidation compared with bare GCE electrode. At an applied potential of +0.60 V, the Cu2O electrode presented a high sensitivity of 121.7 mu A/mM. A linear response was obtained from 0 to 500 mu M, a response time less than 5 s and a detection limit of 38 mu M (signal/noise=3). The Cu2O nanocubes-modified electrode was stable towards interfering molecules like uric acid (UA), ascorbic acid (AA) and dopamine (DA). In short, a facile chemical preparation process of cuprous oxide nanocubes, and the fabricated modified electrode allow highly sensitive, selective, and fast amperometric sensing of glucose, which is promising for the future development of non-enzymatic glucose sensors

Green synthesis of silver nanoparticles using methanolic root extracts of Diospyros paniculata and their antimicrobial activities

Since the discovery and subsequent widespread use of antibiotics, a variety of bacterial species of human and animal origin have developed numerous mechanisms that render bacteria resistant to some, and in certain cases to nearly all antibiotics, thereby limiting the treatment options and compromising effective therapy. In the present study, the green synthesis of nanoparticles is carried out by the reduction of silver acetate in the presence of crude methanolic root extracts of Diospyros paniculata, a member of family Ebenaceae. The UV-Vis absorption spectrum of the biologically reduced reaction mixture showed the surface plasmon peak at 428 nm, a characteristic peak of silver nanoparticles. X-ray diffraction (XRD) analysis confirmed the face-centered cubic crystalline structure of metallic silver. The average diameter of Ag NPs is about 17 nm from Transmission Electron Microscopy (TEM) which is in good agreement with the average crystallite size (19 nm) calculated from XRD analysis. Further the study has been extended to the antimicrobial activity against test pathogenic Gram (+), Gram (-) bacterial and fungal strains. The biologically synthesized silver nanoparticles showed promising activity against all the tested pathogenic strains and the activity has been enhanced with the increased dose levels. (C) 2016 Elsevier B.V. All rights reserved

Low temperature synthesis of various transition metal oxides and their antibacterial activity against multidrug resistance bacterial pathogens

We report on the synthesis and characterization of various transition metal oxides, ZnO, CuO, TiO2 and Fe2O3, using one pot wet chemical method at low temperature. The prepared metal oxide nanoparticles were characterized by X-ray diffraction (XRD), Raman and transmission electron microscopy (TEM) analyses. We tested antibacterial activity of as-prepared transition metal oxides against various multi-drug resistance bacterial pathogens such as Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus. XRD and TEM analyses revealed the average crystallite sizes were 18 nm, 20 nm, 10 nm and 22 nm for ZnO, CuO, TiO2 and Fe2O3 nanoparticles, respectively. Further, the bacterial strains were grown in presence of different concentrations of four nanoparticles and it is evident from the results that ZnO, CuO nano particles showed greater bactericidal effect than nano-TiO2 and nano-Fe2O3, though nano-TiO2 possess less particle size than other fabricated metal oxide nanoparticles

Highly dispersed Cu(II), Co(II) and Ni(II) catalysts covalently immobilized on imine-modified silica for cyclohexane oxidation with hydrogen peroxide

This paper describes the synthesis of Cu(II), Co(II) and Ni(II) catalysts immobilized on imine-functionalized silica gel through a 3-aminopropyltriethoxysilane linker. The synthesized catalysts were characterized by spectroscopic techniques, namely EDS, FTIR, UV-Vis, Si-29 MAS NMR, powder XRD and ESR spectroscopy. These analytical methods evidently confirmed the formation of silica-supported catalysts. Thermal properties of catalysts were studied between 30 and 800 degrees C by thermogravimetric-differential thermal gravimetric (TG-DTG) analysis. The surface roughness of the silica gel was increased upon modification but without losing its lumpy shape, as evidenced by SEM investigation. Magnified SEM and AFM images both suggested the high dispersive nature of the catalysts. Cyclohexane was successfully converted into cyclohexanol and cyclohexanone by the catalysts with the aid of hydrogen peroxide (oxidant). Comparatively, Cu(II) catalyst exhibited better cyclohexane conversion than the other two catalysts. The reusable nature of the catalysts was established by performing five consecutive catalytic runs with Cu(II) catalyst. Comparatively, the present reported catalytic systems were simple, reusable and effective models for higher cyclohexane conversion with better product selectivity