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The chemical preparation and characterization of a novel coordination compound [CuClO4(C4H6N2O)4H2O]ClO4(C4H6N2O)0.08 is reported. The compound crystallizes in the monoclinic space group P21/c with lattice parameters a = 11.2678(5) Å, b = 12.8102(6) Å, c = 19.7250(8) Å, β = 100.3051(15)°, V = 2801.2(2) Å3. The Cu(II) cation is six-coordinated in an elongated distorted octahedral fashion by four N atoms of four 3-amino-5-methylisoxazole ligands, one water oxygen atom, and one perchlorate oxygen atom. In the atomic arrangement, the coordinated and uncoordinated perchlorate anions are grouped in pairs to form anionic layers parallel to the (a, b) plane. A substantial number of H-bonding interactions leads to the formation of an intricate three-dimensional network. The vibrational absorption bands are identified by infrared spectroscopy and the electrical properties are studied by impedance spectroscopy. The DSC analysis agrees with the electrical conductivity results. Magnetic properties are also determined to characterize the complex. [ABSTRACT FROM AUTHOR]

The chemical preparation and characterization of a novel coordination compound [CuClO4(C4H6N2O)4H2O]ClO4(C4H6N2O)0.08 is reported. The compound crystallizes in the monoclinic space group P21/c with lattice parameters a = 11.2678(5) Å, b = 12.8102(6) Å, c = 19.7250(8) Å, β = 100.3051(15)°, V = 2801.2(2) Å3. The Cu(II) cation is six-coordinated in an elongated distorted octahedral fashion by four N atoms of four 3-amino-5-methylisoxazole ligands, one water oxygen atom, and one perchlorate oxygen atom. In the atomic arrangement, the coordinated and uncoordinated perchlorate anions are grouped in pairs to form anionic layers parallel to the (a, b) plane. A substantial number of H-bonding interactions leads to the formation of an intricate three-dimensional network. The vibrational absorption bands are identified by infrared spectroscopy and the electrical properties are studied by impedance spectroscopy. The DSC analysis agrees with the electrical conductivity results. Magnetic properties are also determined to characterize the complex. [ABSTRACT FROM AUTHOR]

Al-doped oxyapatite-type lanthanum silicates La 9.33 Si 6− x Al x O 26− x /2 □ x /2 ( x = 0, 0.4, 0.8 and 1) powders have been prepared by the solid state reaction at high temperature in order to determine the influence of anionic vacancies on the electrical properties of the material. The crystal structure and properties of La 9.33 Si 6− x Al x O 26− x /2 □ x /2 powders have been studied by X-ray diffraction (XRD) patterns, magic-angle spinning nuclear magnetic resonance (MAS-NMR) technique and complex impedance analysis. All the compounds of La 9.33 Si 6− x Al x O 26− x /2 □ x /2 oxyapatites doped with Al 3+ consist of a hexagonal structure with a P63/m space group. Lanthanum silicates doped with trivalent Al 3+ have a higher conductivity than those without trivalent Al 3+ at the Si 4+ site. The extra oxygen O(4) atoms in site 2a (0, 0, 0.25) occupy channels running through the structure that are responsible for the high oxygen ion conduction. However, Al substitution seems to produce oxygen vacancies and create another pathway for oxide ions. The expansion of the channels (La(1)–O(4) distance) leads to an increase in the conductivity. For the best sample ( x = 1), the conductivity observed was 5 × 10 −3 S cm −1 at 750 °C. [ABSTRACT FROM AUTHOR]

The preparation of (LaSr□)SiOO (0 ≤ x ≤ 2) samples with different amounts of cation vacancies is reported. Structure and unit-cell parameters were deduced by Rietveld analysis of XRD patterns. Structural features that enhance oxygen conductivity in Sr-doped apatites are discussed. Up to three components were detected in Si MAS-NMR spectra which change with the amount and distribution of cation vacancies. In general, oxygen conductivity increases with the amount of vacancies at La1 (6h) sites, passing through a maximum for x = 0.4. In the case of activation energy, a minimum is detected near x = 1.2, indicating that entropic and enthalpic change in different ways. The presence of cation vacancies should enhance oxygen hopping along c-axis; however, the analysis of the frequency dependence of conductivity suggests that oxygen motions are produced along three axes. [ABSTRACT FROM AUTHOR]

Hulls are the principal almond by-products and are rich in bioactive compounds, such as polyphenols and fibre. Generally, hulls are used as animal feed; however, because of their valuable chemical composition, alternative applications as a natural food ingredient and dietary supplement should be evaluated. The aim of this study was to assess the physico-chemical and nutritional characteristics and the consumer acceptability of bread produced by replacing 4% and 8% of wheat flour with almond hulls (AHs) obtained from six almond varieties at two ripening stages (green and mature). The use of AHs in bread production increased fibre content, polyphenol content, and antioxidant activity. In particular, bread containing mature AHs showed the highest quantities of fibre and sugars, mainly glucose, whereas bread containing green AHs showed the highest polyphenol content. The polyphenol content and antioxidant activity in bread containing green AHs were 272.88 mg GAE/100 g dry weight and 1145.32 μmol TE/100 g dry weight, respectively, of which 60.5% and 52% were bioaccessible after in vitro digestion. Bread containing AH powder showed slightly lower specific volume, darker crumb colour, and lower hardness than those of the control. Consumer evaluation indicated that breads with 8% AH powder were those with the most overall liking.

Ultrasound-assisted extraction (UAE) was applied as a pretreatment technique to improve the recovery of polyphenols from the almond hulls of four Tunisian and three Italian almond varieties, followed by the characterization with HPLC-DAD. The operating parameters (solid/liquid ratio, extraction time, and ethanol concentrations) were optimized using a Response Surface Methodology. A polynomial equation was calculated to describe the relationship between the operating parameters and dependent variables as total polyphenolic content (TPC) and antioxidant activity (RSA). A desirability function approach was used to determine the optimum conditions for operating parameters: a solid:solvent ratio of 2 g/100 mL, an extraction time of 13 min, and an ethanol concentration of 51.2%. Among the almond varieties, Pizzuta and Fakhfekh showed the highest polyphenol content and antioxidant activity. HPLC-DAD analysis of almond hull extracts confirmed that chlorogenic acid, catechin, and protocatechuic acid were the most important polyphenols in almond hull. The results highlighted that UAE could be an effective technique for the recovery of phenolic compounds from almond hull, thereby making this byproduct a promising source of compounds with potential applications in food and healthcare sectors.

The increasing contamination of fresh water resources by trace metals and persistent organic pollutants is a major environmental concern. In the present study, we investigated, for the first time, the distribution, sources and ecological risk of trace metals and organic pollutants, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), in surface sediments from a Southeastern European river (Someşu Mic River, Romania). Concentrations of Cd, Cr, Cu, Pb, Ni and Zn ranged from 0.04 to 0.4, 9.4 to 43.15, 7.2 to 65.6, 12.3 to 131.4, 14.7 to 47.7 and 42.1 to 236.8 mg kg -1 dw, respectively. Concentrations of total PAHs, PCBs and OCPs ranged from 24.8 to 575.6, 2.7 to 252.7 and 2.1 to 44.3 ng g -1 dw, respectively. Some sediment parameters, i.e., pH, total organic carbon (TOC) and total organic matter (OM) contents, played a significant role in the spatial distribution of contaminants. A combined analysis based on diagnostic ratios and multivariate analyses revealed PAHs originating mainly from pyrolytic sources. PCB compositions showed distinct contamination signatures for tri- to tetra-chlorinated PCBs, characteristic of contamination by Aroclor-1016 and -1254 technical mixtures. The dominant OCP congeners were α-HCH and p,p'-DDD, reflecting past use of technical HCHs and DDTs in agricultural practices. Metal source and pollution status was assessed using geoaccumulation index and enrichment factor, which indicate widespread pollution by Pb, Cd, Zn, Ni and Cu. The use of Sediments Quality Guidelines (SQGs), mean effect range-median quotient (m-ERM-Q) and toxic equivalent factor (TEF) indicated that the highest ecological risks occurred for PCBs and DDTs. This work presents not only initial baseline information on the extent of organic and inorganic contaminations in a river of ecological and economical interest, but also provides a diagnostic ratio/statistical combined approach that can be used to evaluate sediment quality in similar environments., (Copyright © 2019 Elsevier B.V. All rights reserved.)