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The bioavailability and uptake of silver from silver nanoparticles in soil was investigated. Two species of insects, Acheta domesticus and Tenebrio molitor, and two species of plants, Helianthus annuus and Sorghum vulgare, were exposed to a range of concentrations of silver nanoparticles in soil. Silver nanoparticles were charactrized by techniques including transmission electron microscopy, dynamic light scattering, and powder X-ray diffraction. The concentration of silver in insects and plants exposed to silver nanoparticles was measured using inductively coupled plasma-optical emission spectrometry. The results suggested an increase in the levels of silver in both insects and plants as a function of increasing concentrations of silver nanoparticles in soil. The translocation of silver to various parts of dicot plants such as stems and leaves was also observed. Such a result was not observed in the case of monocot plants. Results from this study suggests that silver nanoparticles would be available for uptake by insects and plants in terrestrial ecosystems.

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In this study the effect of sintering process in different temperatures on microstructure and morphological properties of sintered hydroxyapatite (HAp) was investigated. HAp powder was prepared by wet precipitation method from following reagents: Ca(OH)2 + H3PO4 in an alkaline conditions. Thermal analysis (TA), X-Ray diffraction method (XRD), FT-IR spectrometry (FT-IR) and scanning electron microscopy (SEM) were used to elaborate the phase composition and properties of sintered HAp samples and raw HAp powder as well. The total and apparent density and total porosity of sintered compacts, shrinkage and weight loss during the sintering were also measured. The results show that there is a difference in sintering behavior of synthetic hydroxyapatites depending on sintering temperature. The main differences refer to the loss of mass, shrinkage, changes in porosity and density of the investigated materials.

Plant mediated synthesis of metallic nanoparticles is an increasing commercial demand due to the wide applicability in various areas such as electronics, catalysis, chemistry, energy, cosmetics and medicine. In the present investigation, synthesis of gold nanoparticles is done by using fruit extracts of Ananas comosus (L.). Nanoparticles were characterized by using UV visible absorption spectra. Their morphology, elemental composition and crystalline phase were determined by scanning electron microscopy, energy dispersive X-ray spectroscopy and selected area electron diffraction. FT-IR analysis was used to confirm the presence of gold nanoparticles in the extracts. The synthesized gold nanoparticles were generally found to be effective as antimicrobial agents against some important human pathogens like E.coli and Streptobacillus sp. which are affecting and cause diseases like food poisoning and rat-bite fever to human beings respectively.

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