Fractionation and Bioaccessibility of Manganese,Copper, Zinc,Cadmium, and Lead in Commercial Vegetable and Rice Baby Foods Using Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) with Central Composite Design (CCD)

Abstract

Herein the bioaccessibility of Mn, Cu, Zn, Cd, and Pb, selected from essential and toxic elements, was determined in commercially sold vegetable purees intended for infant and toddler consumption. Chemical fractionation studies using water, acetone, diethyl ether, chloroform:methanol, and n-hexane were employed to predict the importance of the protein and lipid parts of a matrix to assess the bioaccessibility data. In addition, in-vitro gastrointestinal digestion was performed to determine the bioaccessibility of the elements using a five level, three factor central composite design (CCD) to maximize the elemental solubility. The total elemental concentrations in all of the fractions were determined by inductively coupled plasma – mass spectrometry (ICP-MS). Based on the consumption of one jar of vegetable/rice-based baby food, Zn was 1.3% of the recommended dietary allowance and Mn was 4.2% of the adequate intake level, while Cu was almost 100% of the adequate intake level. Additionally, Pb was always below the detection limit and Cd was sometimes under the detection limit for the percent bioaccessibility. However, in some samples, Cd was as high as 80% of the tolerable weekly intake level depending on the body weight.     

The Diversity of a Polyclonal FluCell-SELEX Library Outperforms Individual Aptamers as Emerging Diagnostic Tools for the Identification of Carbapenem Resistant Pseudomonas aeruginosa

Textbook procedures require the use of individual aptamers enriched in SELEX libraries which are subsequently chemically synthesized after their biochemical characterization. Here we show that this reduction of the available sequence space of large libraries and thus the diversity of binding molecules reduces the labelling efficiency and fidelity of selected single aptamers towards different strains of the human pathogen Pseudomonas aeruginosa compared to a polyclonal aptamer library enriched by a whole-cell-SELEX involving fluorescent aptamers. The library outperformed single aptamers in reliable and specific targeting of different clinically relevant strains, allowed to inhibit virulence associated cellular functions and identification of bound cell surface targets by aptamer based affinity purification and mass spectrometry. The stunning ease of this FluCell-SELEX and the convincing performance of the P. aeruginosa specific library may pave the way towards generally new and efficient diagnostic techniques based on polyclonal aptamer libraries not only in clinical microbiology.     

ChemInform Abstract: Reaction of Laser‐Ablated Uranium and Thorium Atoms with H2Se: A Rare Example of Selenium Multiple Bonding.

H₂ThSe (I) and H₂USe (II) are obtained by the reaction of laser‐ablated U and Th with a ≈1:1:1 molar mixture of H₂Se, HDSe, and D₂Se under cryogenic conditions (CsI window as substrate, 10 K).     

Low-Dimensional Description of Oscillatory Thermal Convection: The Small Prandtl Number Limit

 Low-dimensional models are derived for transitional, buoyancy-driven flow in a vertical channel with prescribed spatially periodic heating. Stationary characteristic structures (empirical eigenfunctions) are identified by applying proper orthogonal decomposition to numerical solutions of the governing partial differential equations. A Galerkin procedure is then employed to obtain suitable low-order dynamical models. Stability analysis of the fixed points of the low-order systems predicts conditions at the primary flow instability that are in very good agreement with direct numerical solutions of the full model. This agreement is found to hold as long as the low-order system possesses a possible Hopf bifurcation (minimum two-equation) mechanism. The effect of the number of retained eigenmodes on amplitude predictions is examined. Received 25 January 1996 accepted 19 July 1996     

ChemInform Abstract: Thorium Fluorides ThF,ThF2, ThF3, ThF4, ThF3(F2), and ThF5‐ Characterized by Infrared Spectra in Solid Argon and Electronic Structure and Vibrational Frequency Calculations.

Laser‐ablated Th atoms are reacted with different F₂ concentrations to produce ThF_x (x = 1, 2, 3, 4), ThF₃(F₂) and ThF₅^‐.     

The Study of (<Emphasis Type="Italic">n</Emphasis>, 2<Emphasis Type="Italic">n</Emphasis>) Reaction Cross Sections for Ce and Nd Isotopes up to 20 MeV

Neutron cross section calculations for ¹³⁶Ce(n, 2n)¹³⁵Ce, ¹³⁸Ce(n, 2n)¹³⁷Ce, ¹⁴⁰Ce(n, 2n)¹³⁹Ce, ¹⁴²Ce(n, 2n)¹⁴¹Ce, ¹⁴²Nd(n, 2n)¹⁴¹Nd, ¹⁴⁴Nd(n, 2n)¹⁴³Nd, ¹⁴⁶Nd(n, 2n)¹⁴⁵Nd, ¹⁴⁸Nd(n, 2n)¹⁴⁷Nd, and ¹⁵⁰Nd(n, 2n)¹⁴⁹Nd were done in the incident energy range from 10 to 20 MeV. The calculations were performed using three codes TALYS-1.6 for two-component Exciton model, EMPIRE-3.2 Malta for Exciton model, and ALICE/ASH for the Geometry-Dependent Hybrid (GDH) model. The results of model calculations were compared with the available experimental data and also with the evaluated data in the TENDL-2015 (based on the modified TALYS code), ENDF/B-VII.1 libraries. The calculated cross section data were compared with the available experimental data obtained from EXFOR and also compared with semiempirical formulas around 14–15 MeV. The results of model calculation were found to be in good agreement with the experimental data given in literature and semiempirical data around 14–15MeV.     

Effect of surfactant on electrokinetic properties of polyindole/TiO2-conducting nanocomposites in aqueous and nonaqueous media

In this study, polyindole (PIN)/TiO₂ nanocomposites were synthesized with and without the presence of sodium dodecylsulfate, anionic surfactant, with two different PIN contents. The synthesized materials were subjected to various characterizations namely: particle size, apparent density, conductivity, dielectric constants, magnetic susceptibility, elemental analysis, Fourier transform infrared spectroscopy spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Characterization results revealed the successful preparations of PIN/TiO₂ hybrid nanocomposites. Electrokinetic properties of all the materials were determined by zeta (ζ)-potential measurements in aqueous and nonqueous media. Effects of pH, temperature, presence of various electrolytes, and surfactants on electrokinetic properties of the materials were examined.     

Cross-Section Calculation of ( $${n,p}$$ ) and ( $${n,2n}$$ ) Reactions for High Temperature Reactors Construction Materials Tungsten and Rhenium

Physics of Atomic Nuclei - In this study, cross-section calculations for ( $$n,2n$$ ) and ( $$n,p$$ ) reactions of Tungsten isotopes and Rhenium isotopes have been investigated using different...     

New azo‐azomethine‐based transition metal complexes: Synthesis,spectroscopy, solid‐state structure,density functional theory calculations and anticancer studies

A novel tetradentate azo‐Schiff base ligand (H₂L) was synthesized by 2:1 molar condensation of an azo‐aldehyde and ethylenediamine. Its mononuclear Cu(II), Ni(II), Co(II) and Zn(II) complexes were prepared and their structures were confirmed using elemental analysis, NMR, infrared and UV–visible spectroscopies and molar conductivity measurements. The results suggest that the metal ion is bonded to the tetradentate ligand through phenolic oxygens and imine nitrogens of the ligand. The solid‐state structures of the azo‐Schiff base ligand and its Cu(II) complex were determined using single‐crystal X‐ray diffraction studies. The azo‐Schiff base ligand lies on a crystallographic inversion centre and thus the asymmetric unit contains half of the molecule. X‐ray data revealed that keto–amine tautomer is favoured in the solid‐state structure of the ligand. In the structure of the Cu(II) complex, the Cu(II) ion is coordinated to two phenolate oxygen atoms and two imine nitrogen atoms of the azo‐Schiff base ligand with approximate square planar geometry. The anticancer activity of the synthesized complexes was investigated for human cancer cell line (MCF‐7) and cytotoxicity of the synthesized compounds was determined against mouse fibroblast cells (L929). The ligand and its complexes were found to show antitumor activity. The synthesized metal complexes were optimized at the B3LYP/LANL2DZ level and a new theoretical formula for MCF‐7 cells was also derived.