Search

Abstract—The oxidation of metals using a macrocycle involving two oxidants makes it possible to synthesize neutral salts in the most stable oxidation level of the metal via general and close to post-operational and technological schemes regardless of the nature of a metal and acid (acid is used for an anion). The synthesized salts are rather poorly soluble in the liquid medium of the volume phase of the oxidation reaction mixture. Basic salts or their mixtures can be the major reaction product in terms of these schemes under varied reaction conditions. Continuing the reactions of the synthesized neutral salts with diverse acids, a series of neutral salts with different anions can be prepared. These reactions represent the oxidation of neutral and basic salts by available oxidants with increasing oxidation levels of their metals. The process considered is referred to one of the available, competitive, many-profile, and combined methods for the synthesis of metal salts via available post-operational and technological schemes, including those from available secondary metallic raw materials. [ABSTRACT FROM AUTHOR]

Abstract: The effects of neutral salt and alkali on the ion distribution were investigated in two alfalfa (Medicago sativa L.) cultivars, including Zhongmu 1, a high salt-tolerant cultivar, and Algonquin, a low salt-tolerant cultivar. The alkali stress expressed more serious growth inhibition than the neutral salt stress at the same Na+ concentration. Compared with Algonquin, Zhongmu 1 did not exhibit a higher alkali tolerance under the Na2CO3-NaHCO3 treatment with the low Na+ concentration (50 mmol L−1). The alkali increased the accumulation of Na+, Ca2+, and Mg2+ in the root and changed the Ca2+ and Mg2+ balance in the entire alfalfa plant. The salt and alkali stresses decreased the K+ and Fe3+ contents of the roots and leaves, the root Mn2+ content, and the shoot Zn2+ content, but they increased the Fe3+ accumulation of the shoots, the shoot and leaf Cu2+ contents, and the leaf Zn2+ content in both alfalfa cultivars. Based on the results obtained under the conditions of this experiment, we found that the salt and alkali stresses reduced the plant growth in both alfalfa cultivars, while the alkali caused a stronger stress than the neutral salt in alfalfa. Thus, we conclude that under hydroponic conditions, the deleterious effects of the alkali on plants are due to the distribution change of some trophic ion balance in the roots, shoots, and leaves of the plants by causing of Na+, CO32−, and/or HCO3− stresses.

The effect of neutral salts on protein conformation was first analyzed by Hofmeister in 1888, however, even today this phenomenon is not completely understood. To clarify this effect, we studied changes in the secondary structure of two proteins: human serum albumin with predominantly α-helical structure and porcine pancreas β-trypsin with the typical β-structural arrangement in aqueous solutions of neutral salts (KSCN, KCl, (NH4)2SO4). The changes in the secondary structure were studied at 23 °C and 80 °C by using the second derivative deconvolution method of the IR spectra. Our results demonstrated that the ability of the salts to stabilize/destabilize these two proteins correlates with the Hofmeister series of ions. At the same time, some exceptions were also observed. The destabilization of the native structures of both α-helical albumin and β-structural trypsin upon interaction with neutral salts leads to the formation of intermolecular β-sheets typical for amyloid fibrils or amorphous aggregates. Thus, our quantitative FTIR-spectroscopy analysis allowed us to further clarify the mechanisms and complexity of the neutral salt actions on protein structures which may lead to strategies preventing unwelcome misfolding of proteins.

By employing 1,2,3,4-butanetetracarboxylic acid (BTCA) as the finishing agent, SHP as the catalyst and neutral salts NaCl and Na2SO4 as the additives, anti-wrinkle finish of cotton fabrics was carried out here. According to the Donnan equilibrium model and the actions of neutral salts in dyeing process of cellulosic fabrics, NaCl and Na2SO4 should both promote the adsorption of BTCA anions onto the surface of fibers and diffusion into the interior of fibers. Consequently, BTCA would crosslink the interior molecular chains of cellulose, improving the anti-wrinkle properties of treated fabrics. In fact, experimental results confirmed the hypothesis that the two additives of neutral salts indeed both improved wrinkle recovery angle (WRA) of the treated fabrics and the optimal molar ratio of NaCl or Na2SO4 to BTCA was 0.2:1 or 0.3:1, respectively. The neutral salts reduced the dosage of BTCA without decreasing WRA, reducing the manufacturing cost. Besides, the fabrics treated with neutral salts presented good durability. Furthermore, thermogravimetric analysis (TGA), Xray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analyses revealed that neutral salts could catalyze the formation of BTCA anhydride by decreasing hydrogen-bond interactions between BTCA molecules. [ABSTRACT FROM AUTHOR]

The effects of salts and pH on a mixture of homologous ketone flavours (2-hexanone, 2-heptanone and 2-octanone) binding to salt-extracted pea protein isolates (PPIs) were studied using GC/MS in an aqueous model system. Ionic strength, the specific flavour compound and pH were found to significantly affect protein-flavour binding. Comparing the univalent (NaCl) and divalent (CaCl 2 ) cations, higher concentrations of NaCl (0.25-1 M) greatly promoted protein-flavour binding compared to CaCl 2 , while lower concentrations (0.05-0.1 M NaCl and 0.25 M CaCl 2 ) decreased flavour retention. Considering the effect of anions (0.5 M), flavour binding by PPIs was dependent upon the position of the anions in the lyotropic series such that binding decreased in the order: Na 2 SO 4 >> NaCl > NaCH 3 COO = no salt > NaSCN. In terms of the effect of pH, overall flavour binding followed the order: pH 5 > pH 7 > pH 9 > pH 11 > pH 3. Competitive binding between the selected flavour mixture and PPIs was also observed as evidenced by 2-octanone more effectively binding to PPIs than 2-heptanone and 2-hexanone. This research supported existing knowledge on the effects of salts and pH on flavour partitioning with and without protein present. This further promotes utilization of plant proteins in aqueous food systems to achieve desired flavour attributes. [ABSTRACT FROM AUTHOR]

Copyright of Minufiya Journal of Agricultural Research is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses results of a study that examines the effects of Setaria viridis seeds and seedlings subjected to saline and alkaline stress on germination and growth indices and physiological parameters. The study showed reduced germination indices and germ and root growth severely inhibited with increased concentrations. It observes that the damage caused by alkaline stress came from greater influx of sodium than by saline stress.

Abstract: Antennal gustatory sensilla of the ground beetle Pterostichus aethiops (Pz., 1797) (Coleoptera, Carabidae) respond to salts, the three sensory cells, A-, B- and C-cells, producing action potentials that are distinguished by differences in their shape, amplitude, duration and polarity of spikes. The B-cell (salt cell) was highly sensitive to both ionic composition and concentration of the tested nine salt solutions showing phasic-tonic type of reaction with a pronounced phasic component. The stimulating effect was dominated by the cations involved, and in most cases, monovalent cations were more effective stimuli than divalent cations. Salt concentration/response relations were tested with NaCl at 1, 10, 100 and 1000mmoll-1: mean firing rates increased from 0.8 to 44 spikes per first second of the response, respectively. The pH value of the stimulating solutions also influenced the B-cell rate of firing. By contrast, the pH level of stimulus solutions influenced the A-cells’ phasic-tonic response more than the ionic composition or concentration of these solutions. Compared to a standard 100mmoll-1 salt (NaCl) solution (pH 6.3), alkaline solutions of the salts NaCH3COO, Na2HPO4 and Na2B4O7 (pH 7.9, 8.5 and 9.3, respectively, all 100mmoll-1) induced remarkably stronger responses in the A-cell. On the other hand, the reaction to an acid solution of NaH2PO4 (pH 4.5, 100mmoll-1) was minimal. A-cell responses to neutral salts like NaCl, KCl, CaCl2, MgCl2 and C5H14NOCl (pH 6.1–6.5) varied largely in strength. Very low or no responses were observed with chlorides of divalent cations, CaCl2 and MgCl2, and choline chloride (C5H14NOCl), indicating that the ionic composition of the solutions also affected A-cell responses. Neural activity of the C-cell was not influenced by the salt solutions tested. [Copyright &y& Elsevier]

The effects of polycation structure, counterions and the nature of the solvent on the interaction between low-molecular-weight salts with some cationic polyelectrolytes in water and methanol were investigated. The polyelectrolytes used in this study were cationic polymers with quaternary nitrogen atoms in the backbone with or without a nonpolar side chain (polymer type PCA5H1, PCA5D1 and PCA5) or tertiary amine nitrogen atoms in the main chain (polymer type PEGA). LiCl, NaCl, KCl, NaBr, NaI and Na2SO4 were used as low-molecular-weight salts. The interaction between polycations and salts was followed by viscometric and conductometric measurements. The study of the interaction of monovalent counterions with cationic polyelectrolytes emphasized an increase in the interaction with the decrease in the radius of the hydrated counterion, both for strong polycations and for weak polycations, suggesting that counterion binding is nonspecific. In the case of SO2− 4 anions, the Λm− c1/2 curve passes through a minimum at cp values between 1 × 10−3 and 3 × 10−3 unit mol/l; this phenomenon can be explained by the maximum counterion interaction owing to the capacity of the polyvalent counterion to bind two charged groups by intra- or interchain bridges. The investigation of the influence of the polycation structure on the counterion binding indicated an increase in charged group–counterion interactions with a decrease in the nonpolar chain length and an increase in the quaternary ammonium salt group content (charge density) in the chain. The polyelectrolyte with tertiary amine groups in the chain, PEGA, showed, on one hand, a cation adsorption order as K+>Na+>Li+ and, on the other hand, a stronger association between ions and PEGA chains in methanol than in water owing to the poorer solvating effect of methanol on the cations. [ABSTRACT FROM AUTHOR]

The effect of neutral salts on protein conformation was first analyzed by Hofmeister in 1888, however, even today this phenomenon is not completely understood. To clarify this effect, we studied changes in the secondary structure of two proteins: human serum albumin with predominantly α-helical structure and porcine pancreas β-trypsin with the typical β-structural arrangement in aqueous solutions of neutral salts (KSCN, KCl, (NH4)2SO4). The changes in the secondary structure were studied at 23 °C and 80 °C by using the second derivative deconvolution method of the IR spectra. Our results demonstrated that the ability of the salts to stabilize/destabilize these two proteins correlates with the Hofmeister series of ions. At the same time, some exceptions were also observed. The destabilization of the native structures of both α-helical albumin and β-structural trypsin upon interaction with neutral salts leads to the formation of intermolecular β-sheets typical for amyloid fibrils or amorphous aggregates. Thus, our quantitative FTIR-spectroscopy analysis allowed us to further clarify the mechanisms and complexity of the neutral salt actions on protein structures which may lead to strategies preventing unwelcome misfolding of proteins. [ABSTRACT FROM AUTHOR]