Influence of citrate and PEG coatings on the bioaccumulation of TiO2 and CeO2 nanoparticles following dietary exposure in rainbow trout

Background This study was conducted to provide much needed information on the potential of low solubility, highly biodurable nanoparticles (NPs) (TiO2 and CeO2 NPs), to bioaccumulate in fish and to investigate the relationship between an engineered nanomaterials surface coating, uptake and biokinetics in vivo. Rainbow trout (Oncorhynchus mykiss) were fed diets spiked with uncoated or surface coated (polyethylene glycol (PEG) or citrate (CIT)) TiO2 and CeO2 NPs (100 mg NPs/kg feed) for 10 days and thereafter fish were allowed to depurate for 42 days. Special care was taken to measure the real dispersed and actual administered concentrations, taking into consideration any potential losses from leaching, and to characterise the form (size, aggregation state, charge) of the NPs to which the fish were exposed. Results The coatings had an influence on levels of uptake and distributions. Most notably a higher uptake of PEG and CIT coated TiO2 and CeO2 NPs compared to fish exposed to uncoated materials was observed. The elimination of any Ti from tissues was rapid during the first day of depuration, whereas Ce levels remained in fish tissues (stomach, intestine and liver) with differences in depuration and redistribution of the three types of CeO2 NPs. However, no bioaccumulation potential for both tested metal oxide NPs in fish irrespective of coatings is expected according to BMF values < 1. Conclusions Distinct uptake, distribution and depuration kinetics in rainbow trout have been evidenced for different metal oxide NPs (TiO2 and CeO2 NPs). Coatings influenced uptake and in some cases led to slower depuration and distinct distributions, but do not make the uncoated NPs studied bioaccumulative (BMF > 1). Graphical Abstract

Electronic Properties of Ethylene Glycol and Styrene Glycol: DFT Calculation

In this paper we worked on a theoretical study of Ethylene glycol and styrene glycol Which is based on density functional theory, implement in computational program SIESTA with use of general gradient approximation (GGA) of Perdew, Burke and Emzerhof (PBE) scheme for an account of exchange co-relation effect to obtain density of state , projected density of state and charge density. Keywords: Density functional theory, SIESTA, Density of state .Projected density of state ,charge density .

Elastic and Inelastic form factors with inclusion 2-body short-range correlations effect

The charge distributions and elastic electron form factors for ¹⁸O, ^42,44Ca,⁵⁸Ni, and ¹¹⁸Sn nuclei are considered using the cluster extension of the 1- and 2-body terms. Inelastic electron form factors to 2+ states with Core-Polarization effects studied where the nuclear collective modes beside to the shell model transition density are considered. The influence of SRC's be calculated by the parameter β which is introduced into the ground state charge distribution concluded the Jastrow function. It is found that the inclusion of 2-body correlations are necessary to describe the observed data of elastic and inelastic form factor at high range of momentum transfer q > 3 fm^-1.