A New Caco-2 Cell Model of in vitro Intestinal Barrier: Application for the Evaluation of Magnesium Salts Absorption

Experimental data concerning the bioavailability of the different Mg-salts in human organism is inconsistent. Mg-absorption reported by clinical studies largely varies depending on the method used for evaluation. The aim of this study was to evaluate the bioavailability and accessibility of magnesium bound in different Mg-salt compounds, using an in vitro model of intestinal cell barrier. The study included a variety of inorganic (oxide, sulphate, chloride, carbonate) and organic salts (lactate, citrate, pidolate). Caco-2 cells were cultivated in a complete culture medium with different magnesium salts treatments in ascending concentrations. The viability and quantity of cells was analysed by FACS. Mg-absorption was analysed by a direct colorimetric assay, measured by spectrometry. T-test identified a significant decrease in cell count treatment with mg-lactate compared with citrate. Mg-pidolate showed a significantly higher cell viability compared with Mg-citrate, Mg-lactate and Mg-chloride. Even though the difference was not significant, we showed that an increase in Mg2+ salt concentration progressively decreased the cell count and the viability and the effect was universal for all the used Mg-salt treatments. Mg-citrate, chloride, and sulphate showed a significantly lower absorption compared to Mg-carbonate, pidolate and oxide. Our in vitro monolayer model of human intestinal transport showed that viability and quantity of cell decreased with increasing Mg-concentration. We admit that our experiment model may have some limitations in accurately describing an in vivo Mg2+ absorption. Moreover, it is also necessary to assess the relevance of our data in vivo and especially in clinical practice.

Reasons for Reduced Moisture Resistance of Sulfur-Extended Asphalt Concrete

The paper presents the results of a study of the mechanism for reducing the moisture resistance of sulfur-extended asphalt concrete. It is shown that a decrease in moisture resistance occurs due to the occurrence of chemical and physical processes. At the same time, it was found that during the manufacture of sulfur-bitumen composites, toxic gases H2S and SO2 are formed, which are capable of interacting with a mineral filler, as well as the interaction of sulfur with a mineral powder with the formation of sulfur-containing water-soluble salts, the extraction of which leads to a decrease in the moisture resistance of sulfur-bitumen materials. The change in the rate of leaching of these substances from the composite is due to the physical process caused by the crystallization of sulfur and the formation of a capillary structure, which significantly increases the rate of leaching of calcium and magnesium salts, which are products of dissolution or hydrolytic decomposition of water-soluble products of the interaction of sulfur, H2S and SO2 gases with calcium and magnesium carbonates. The intensity of chemical and physical processes intensifies with an increase in the amount of sulfur in sulfur-bitumen materials.

Impact of Magnesium Salt on the Mechanical and Thermal Properties of Poly(vinyl alcohol)

The effects of magnesium salts with various anion species on the structure and properties of a poly(vinyl alcohol) (PVA) film were studied. The glass transition temperature of the PVA film increased following the addition of a magnesium salt. Furthermore, the salt greatly enhanced the modulus and yield stress and reduced the crystallinity of the film. These effects were attributed to the strong ion–dipole interactions between the magnesium salts and the PVA chains. The strength of interaction, i.e., the reduction of segmental motions, depended on the anion species in the following order: Mg(ClO4)2, MgBr2, MgCl2, Mg(CH3COO)2, and MgSO4. The order corresponded to the Hofmeister series, which predicts the ability to break the structure of water.

Allocation of a deep-lying brine aquifer in the rocks of a chemogenic section based on the data of geophysical well logging and 2D seismic exploration

Advancement in the production of potassium fertilizers is an important strategic task of Russian agricultural industry. Given annually growing production rates, the reserves of discovered potassium-magnesium salt deposits are noticeably decreasing, which creates the need to ensure stable replenishment of the resource base through both the discovery of new deposits and the exploitation of deep-lying production horizons of the deposits that are already under development. In most cases, deposits of potassium-magnesium salts are developed by underground mining. The main problem for any salt deposit is water. Dry salt workings do not require any additional reinforcement and can easily withstand rock pressure, but with an inflow of water they begin to collapse intensively – hence, special attention is paid to mine waterproofing. Determination of spatial location, physical and mechanical properties of the aquifer and water-blocking stratum in the geological section represent an important stage in the exploration of a salt deposit. The results of these studies allow to validate an optimal system of deposit development that will minimize environmental and economic risks. On the territory of Russia, there is a deposit of potassium-magnesium salts with a unique geological structure – its production horizon lies at a considerable depth and is capped by a regional aquifer, which imposes significant limitations on the development process. To estimate parameters of the studied object, we analyzed the data from CDP seismic reflection survey and a suite of methods of radioactive and acoustic well logging, supplemented with high-frequency induction logging isoparametric sounding (VIKIZ) data. As a result of performed analysis, we identified location of the water-bearing stratum, estimated average thickness of the aquifers and possible water-blocking strata. Based on research results, we proposed methods for increasing operational reliability of the main shaft in the designed mine that will minimize the risks of water breakthrough into the mine shaft.

Study of Sodium Chloride Production Using Gradual Evaporation of Seawater from Nggolonio Sea, East Nusa Tenggara

Sea water as a raw material resources for the kitchen salt production, besides containing NaCl, has also containing other dissolved salts such as hygroscopic calcium and magnesium salts. The high content of other salts cause industrial NaCl has a low quality. This aim research was to find out the effect of seawater evaporation on NaCl content changes. Seawater obtained from Nggolonto, Nagekeo, NTT, was used with an initial volume of 200 mL, then it was concentrated in varying of final volume, i.e. 20, 23, 25, 27 and 29 mL. The NaCl content was calculated based on total chloride ion content, corrected toward magnesium and calcium ions content and the presence of sulphate anion. In addition, the chloride and magnesium also calcium ions content was analyzed volumetrically, while the sulphate anion was determined spectrophotometrically. The research result showed that NaCl content increase significantly up to 27 mL of final volume and was constantly afterward. Furthermore, the highest of NaCl content obtained from final volume of 29 mL was 96.01%. Nevertheless, comparing to SNI 06-0303-1989, its content was still below the standard of 98.5%.

Supplementation with Magnesium Salts–A Strategy to Increase Nutraceutical Value of Pleurotus djamor Fruiting Bodies

The use of substrates supplemented with minerals is a promising strategy for increasing the nutraceutical value of Pleurotus spp. The current research was performed to analyze the effect of substrate supplementation with magnesium (Mg) salts on the Mg content, biomass, and chemical composition of pink oyster mushroom (Pleurotus djamor) fruiting bodies. Before inoculation, substrate was supplemented with MgCl2 × 6 H2O and MgSO4, Both salts were applied at three concentrations: 210, 420, and 4200 mg of Mg per 2 kg of substrate. The harvest period included three flushes. Substrate supplementation with 4200 mg of Mg caused the most significant decrease in mushroom productivity, of about 28% for both Mg salts. The dry matter content in fruiting bodies was significantly lower in the treatment in which 210 mg of Mg was applied as MgSO4 in comparison to the control. Supplementation effectively increased the Mg content in fruiting bodies of P. djamor by 19–85% depending on the treatment, and significantly affected the level of remaining bioelements and anions. One hundred grams of pink oyster fruiting bodies, supplemented with Mg salts, provides more than 20% of the Mg dietary value recommended by the Food and Drug Administration (FDA); thus, supplementation can be an effective technique for producing mushrooms that are rich in dietary Mg. Although P. djamor grown in supplemented substrate showed lower productivity, this was evident only in the fresh weight because the differences in dry weight were negligible. Mg supplementation increased the antioxidant activity of the fruiting bodies, phenolic compounds, and some amino acids, including L-tryptophan, and vitamins (thiamine and l-ascorbic acid).

Complex character of the influence of polycarboxylic and phosphonic acids on the crystallization of calcium and magnesium salts in dynamic conditions

The influence of water-soluble organic compounds (adipic, polyaspartic and phosphonic acids) and their compositions on the crystallization of calcium and magnesium salts in dynamic conditions has been studied. It is found that the induction period of phase formation increases in the presence of polyaspartic and phosphonic acids 2.3–5.2 times in the range of their content from 0.05 to 0.2 ppm. The results of XRD and electron microscopic studies confirm the change in the phase composition and morphology of the crystalline precipitate that is formed. The dibasic carboxylic acid influence on the induction period, composition and structure of the precipitate is much less. It is established that the composition of organic acids also increases the induction period of phase formation. The complex inhibitor provides an increase in the critical supersaturation level in the system. The phosphonic and carboxyl groups of the inhibitor interact with calcium and magnesium ions and block the crystallization nuclei. When interacting with the dicarboxylic acid and polyacid adsorption on the surface of the formed crystals, the microcrystals dissolve.

Antioxidant Activity of Vitamin E Concentrate from Magnesium Salts of Palm Fatty Acid Distillate (Mg-PFAD)

Vitamin E concentrate was produced through saponification of palm fatty acid distillates (PFAD) and magnesium oxide to form Mg-PFAD, followed by three-stages vitamin E extraction with isopropanol, hexane, or ethanol. The vitamin E-rich extracts were evaporated to remove solvent and produced vitamin E concentrate. The objectives of this research were to investigate the effect of organic solvent’s types and solvent to Mg-PFAD mass ratios on vitamin E concentration, solvent selectivity, and antioxidant activity of the vitamin E concentrate. Vitamin E concentrates obtained after isopropanol extraction had vitamin E concentration of 784 ppm with vitamin E recovery of 16 mg tocopherol/100 mg tocopherol in Mg-PFAD, while vitamin E concentrates obtained after hexane extraction had vitamin E concentration of 574 ppm with vitamin E recovery of 35 mg tocopherol/100 mg tocopherol in Mg-PFAD. Isopropanol extraction produced vitamin E concentrate with the highest selectivity for vitamin E and the highest antioxidant activity of 79% IC. It was found that vitamin E concentration was not proportional to the antioxidant activity of the vitamin E concentrate.Keywords: Direct solvent extraction, palm fatty acid distillate, saponification, vitamin E, unsaponifiable matter