High Concentrations Of Mg Research Articles

Effect of magnesium and calcium ions on the strength and biofunctionality of GelMA/SAMA composite hydrogels.

Natural polymers and synthetic polymers have been extensively studied as scaffold materials, with the former offering advantages such as biocompatibility, biodegradability, and structural similarity to the natural extracellular matrix (ECM). However, the use of natural polymers in extrusion-based 3D printing has been limited by their poor mechanical properties and challenging rheological properties. In this study, gelatin and sodium alginate were utilized as scaffold materials, with the addition of Ca2+ and Mg2+ components to enhance their physical and chemical properties, and influence early cell behavior. Subsequently, these materials were fabricated into scaffolds using 3D printing. Our results demonstrated that the addition of Ca2+ and Mg2+ could improve the compactness of the 3D network structure, mechanical strength, swelling properties and degradation properties of methacrylated gelatin/methacrylated sodium alginate (GelMA/SAMA) composite hydrogel. In vitro cell tests revealed that the GelMA/SAMA composite hydrogel exhibited negligible cytotoxicity and promoted early cell viability, particularly with the higher concentration of Mg2+ in the material. Notably, the extrusion 3D printing process successfully produced GelMA/SAMA scaffolds. These results collectively indicate that GelMA/SAMA composite scaffolds hold promise as potential biomaterials for tissue engineering applications.

Understanding the mechanisms behind the antibacterial activity of magnesium hydroxide nanoparticles against sulfate-reducing bacteria in sediments

Nanomaterials, with their small size, surface characteristics, and antibacterial properties, are extensively employed across environmental, energy, biomedical, agricultural, and other industries. This study examined the antibacterial efficacy of magnesium hydroxide (Mg(OH)2) nanoparticles (NPs) against sulfate-reducing bacteria (SRB) within sediments. The inhibitory effects of two types of Mg(OH)2 NPs with distinct particle sizes (20.3 and 29.6 nm) and concentrations (0–10.0 mg/mL) were examined under optimal treatment conditions. The antibacterial mechanisms of Mg(OH)2 NPs through direct contact and dissolution effects were determined. The results revealed a correlation between the concentration, particle size, and inhibitory activity, with the smallest NPs (20.3 nm) at the highest concentration (10.0 mg/mL) substantially reducing SRB counts from 8.77 ± 0.18 to 6.48 ± 0.13 log10 colony forming units/mL after 6 h treatment. Treatment with high concentrations of Mg(OH)2 NPs induced cellular damage, reduced intracellular lactate dehydrogenase activity, and elevated intracellular catalase activity and H2O2 content, suggesting that the contact effect of NPs stimulated SRB. This leads to oxidative stress response and structural damage to the cell membrane, which has emerged as the primary driver of the antibacterial action of Mg(OH)2 NPs. This study presents a novel nanomaterial that can inhibit and control SRB in natural sedimentary environments.

Impact of Strontium, Magnesium, and Zinc Ions on the In Vitro Osteogenesis of Maxillary Sinus Membrane Stem Cells.

Human Maxillary Sinus Membrane Stem Cells (hMSMSCs) contribute significantly to bone formation following maxillary sinus floor augmentation (MSFA). The biological behavior of mesenchymal stem cells is notably influenced by varying concentrations of magnesium (Mg2+), strontium (Sr2+), and zinc (Zn2+) ions; however, their specific effects on hMSMSCs have not been comprehensively studied. We isolated hMSMSCs and identified their mesenchymal stem cell characteristics by flow cytometry and multilineage differentiation experiments. Subsequently, the hMSMSCs were cultured in media containing different concentrations of these metal ions. The proliferation and viability of hMSMSCs were assessed using CCK-8 and Calcein AM/PI staining. After osteogenic induction, cells were evaluated for alkaline phosphatase (ALP) activity, ALP staining, and Alizarin Red staining. Additionally, qRT-PCR was used to detect differences in osteogenic gene expression, and immunofluorescence staining was used to observe variations in OCN protein levels. The results indicated that 1 mM Mg2+, 0.01 mM Sr2+, and 0.001 mM Zn2+ significantly improved the proliferation and activity of hMSMSCs. These concentrations also notably enhanced ALP secretion, increased bone-related gene expression, and augmented osteocalcin expression and formation of extracellular calcium nodules, thereby improving osteogenic differentiation. However, higher concentrations of Mg2+, Sr2+, and Zn2+ decreased cell viability and osteogenic differentiation. Mg2+, Sr2+, and Zn2+ promote osteogenic differentiation and proliferation of hMSMSCs in a concentration-dependent manner, indicating that the type and concentration of ions in the extracellular environment can significantly alter hMSMSCs behavior, which is a crucial consideration for material design in maxillary sinus elevation applications.

Surface Modification of AM60 Mg-Al Alloy with Vanadium and V2O5 Sputtered Deposits: Activity in Marine Ambience

Vanadium (~450 nm) and V2O5 (~350 nm) were deposited by DC magnetron sputtering on an AM60 substrate to improve its degradation resistance in marine ambience. According to Raman and XPS analysis, the vanadium nanofilm mainly consists of amorphous V2O3, while V2O5 comprises two sheets of VO5 and VO4 units. After 30 days of immersion of the coated AM60 in a marine model solution (SME), the shift of the pH of the SME to more alkaline values was less pronounced for V2O5-AM60 because of the HCl acid formation during the partial dissolution of V2O5 in the presence of NaCl, and thus, a higher concentration of Mg2+ ions ~100 mg L-1 was released from the Mg (AM60) matrix. The lower concentration of ~40 mg L-1 from the V-AM60 surface was attributed to the possible intercalation of the released Mg ions (cations) into the conductive tunnels of V2O3 as the main component of the vanadium sputtered deposit. This oxide has been reported as a material for high-capacitive energy storage. In this way, the V-deposit provided longer partial protection for the AM60 surface (Mg matrix) from localized pitting attacks.

Enzymatic characterization and dominant sites of foot-and-mouth disease virus 2C protein

Foot-and-mouth disease virus (FMDV) 2C protein is a conserved non-structural protein and crucial for replication of the virus. In this study, FMDV 2C protein was prepared and the enzymatic activities were investigated in detail. The protein could digest ssDNA or ssRNA into a small fragment at about 10 nt, indicating that the protein has nuclease activity. But it did not show digestion to blunt-end dsDNA or dsRNA. The nuclease activity of 2C protein could be inhibited in 2 mM Zn2+ or Ca2+ while enhanced by Mg2+ or Mn2+. FMDV 2C protein exhibited unwinding activity to all the three kinds of dsDNA and dsRNA (5′ protruded, 3′ protruded, and blunt-end). The unwinding velocity to 5′ protruded dsRNA was higher than to the blunt-end dsRNA. 2C protein only showed unwinding activity in high concentration of Mg2+, but no unwinding activity in physiological concentrations of Mg2+ and Ca2+, as well as in cell lysate. The 2C protein could catalyze two structured ssRNA to form double strand, thus it was proved to have RNA chaperone activity. The Mg2+ and ATP in different concentrations did not show promotion to the RNA chaperone activity. Finally, six mutant proteins (K116A, D160A, D170A, N207A, R226A, and F316A) were constructed and the enzymatic activities were analyzed. All the six mutations reduced the ATPase activity, D170A and F361A could inactivate the nuclease activity, while the N207A and F316A could inactivate the helicase activity. Our study provides a comprehensive understanding of the enzymatic activities of FMDV 2C protein.

Influence of Different Ions on Pulse Electrodeposition of CaCO3 Scales in the Simulated Seawater.

In the circulating water system of coastal power plants, various kinds of ions have a great influence on the formation and growth of CaCO3 scales. This paper focuses on investigating the influence of existing ions on the pulse electrodeposition behaviors of CaCO3 scales. Different concentrations of ions, such as Fe3+, Mg2+, PO43- and SiO32-, are introduced to simulate the actual seawater environment, and their influence on the CaCO3 scale deposition behaviors is assessed by linear sweep voltammetry, chronoamperometry, and electrochemical impedance spectroscopy tests. The surface coverage of the CaCO3 scale layer is evaluated through the residual current density and polarization resistance values, while the crystal structure and surface compactness of the layer are confirmed by the scanning electron microscope and X-ray diffractometer tests. Results indicate that high concentrations of Mg2+, Fe3+, and PO43- ions have the most significant inhibitory effect on the pulse electrodeposition of CaCO3 scales, among which the inhibition effect of Mg2+ ions is mainly reflected in the change of crystal morphology of CaCO3, that is, the crystallization growth process is inhibited. The inhibition effect of PO43- ions is mainly reflected in the gradually reduced coverage and density of CaCO3 crystals on the electrode surface, suggesting that the crystallization nucleation process is inhibited, while Fe3+ ions have a certain inhibition effect on both the crystallization nucleation and growth processes. Furthermore, lower concentrations of SiO32- ions also display a significant inhibition effect on the crystallization nucleation and growth process, and the inhibition effect weakens with increased concentration. This study provides a theoretical basis for exploring the removal of ions in the industrial water softening field.

Simulations predict preferred Mg2+ coordination in a nonenzymatic primer-extension reaction center

The mechanism by which genetic information was copied prior to the evolution of ribozymes is of great interest because of its importance to the origin of life. The most effective known process for the nonenzymatic copying of an RNA template is primer extension by a two-step pathway in which 2-aminoimidazole-activated nucleotides first react with each other to form an imidazolium-bridged intermediate that subsequently reacts with the primer. Reaction kinetics, structure-activity relationships, and X-ray crystallography have provided insight into the overall reaction mechanism, but many puzzles remain. In particular, high concentrations of Mg2+ are required for efficient primer extension, but the mechanism by which Mg2+ accelerates primer extension remains unknown. By analogy with the mechanism of DNA and RNA polymerases, a role for Mg2+ in facilitating the deprotonation of the primer 3′-hydroxyl is often assumed, but no catalytic metal ion is seen in crystal structures of the primer-extension complex. To explore the potential effects of Mg2+ binding in the reaction center, we performed atomistic molecular dynamics simulations of a series of modeled complexes in which a Mg2+ ion was placed in the reaction center with inner-sphere coordination with different sets of functional groups. Our simulations suggest that coordination of a Mg2+ ion with both O3′ of the terminal primer nucleotide and the pro-Sp nonbridging oxygen of the reactive phosphate of an imidazolium-bridged dinucleotide would help to pre-organize the structure of the primer/template substrate complex to favor the primer-extension reaction. Our results suggest that the catalytic metal ion may play an important role in overcoming electrostatic repulsion between a deprotonated O3′ and the reactive phosphate of the bridged dinucleotide and lead to testable predictions of the mode of Mg2+ binding that is most relevant to catalysis of primer extension.

Multivariate Analysis of Okra [Abelmoschus esculentus (L.) Moench] Genotypes and Hybrids based on Mineral Content

Background: In 2021, the world production of okra [Abelmoschus esculentus (L.) Moench] was over 10.8 million tonnes which is led by India (about 60%). The objective of this study was to determine mineral content of genotypes and hybrids of okra identified by our in-house heterosis breeding programme. Methods: The samples were digested in a heating block using nitric acid and hydrogen peroxide and analyzed using inductively coupled plasma mass spectrometry (ICP-MS) for mineral profiling of okra samples. Result: The results were evaluated using multivariate analysis. The genotype EC169474 was with the highest concentration of minerals Na (184.91 μg/g), K (14613.52 μg/g) and Fe (268.76 μg/g), while, EC169477 was found to have highest concentration of Mg (6530.76 μg/g) and Ca (273.58 μg/g). Comparatively, in hybrids, EC 169470 x EC169474 contains highest concentration of minerals Na (177.27 μg/g) and Ca (253.01 μg/g), EC169474 x EC169477 contains highest Mg (6301.74 μg/g) and hybrid EC169468 x EC169477 contains highest K (14412.99 μg/g) and Fe (246.51 μg/g). Principal component analysis (PCA) reveals that the element that contributed most for the variability between the genotypes and hybrids was K, moderate contribution by Ca, Fe and Na, while, Mg being the least. Score plot of principal components reveals EC169470 and EC169477 among the most variable genotypes and EC169470 x EC169477 was the most variable hybrid. Hierarchical cluster analysis (HCA) tends to separate all analyzed samples in two major clusters. However, the genotypes EC169474 and EC169477 were grouped in hybrid cluster, while, hybrid EC169470 ´ EC169477 grouped with genotype cluster. The multivariate analysis revealed a systematic difference in the mineral content of okra. The results presented in this study are of great value for nutritionally dense breeding programmes for okra that provides important nutritional diversity by hybrids.

Feasibility of Using Pulse Drip Irrigation for Increasing Growth, Yield, and Water Productivity of Red Raspberry

Pulse irrigation, the practice of applying water in small doses over time, is known to reduce deep percolation and runoff and, relative to irrigating in single continuous applications, can increase plant growth and production by supplying water and nutrients at an optimal rate. The objective of the present study was to determine whether pulse irrigation was beneficial in red raspberry (Rubus idaeus L. ‘Wakefield’). Treatments included continuous or pulse drip irrigation and were evaluated for three growing seasons (2018–20) in a commercial field with silt loam soil. Continuous irrigation was applied up to 4 hours/day, whereas pulse irrigation was programmed to run for 30 minutes every 2 hours, up to eight times/day, using the same amount of water as the continuous treatment. Pulsing improved soil water availability relative to continuous irrigation and, by the second and third year, increased fruit production by 1210 to 1230 kg·ha−1, which, based on recent market prices, was equivalent to $2420 to $2460/ha per year. Much of this yield increase occurred during the latter 3 to 4 weeks of the harvest season and was primarily due to larger fruit size during the second year and more berries per plant during the third year. In 1 or both years, pulse irrigation also produced more canopy cover, larger cane diameters, and higher concentrations of Mg and S in the leaves than continuous irrigation, but it reduced K and B in the soil and had variable effects on sugar-to-acid ratio in the berries. On the basis of these results, pulsing appears to be an effective means of irrigating raspberry plants in sandy or silty loam soils, but more research is needed to determine whether it is useful technique in heavier soil types.

Magnesium-Substituted Brushite Cement: Physical and Mechanical Properties

Brushite cements (BrCs) are calcium phosphate-based materials that are being widely used in hard tissue engineering applications due to their osteoconductivity, injectability, and bioresorbability. Therefore, the goal was to evaluate the effects of Mg concentration on the phase composition, setting time, and strength of BrC. Mg, which plays a vital role in bodily functions and bone health, was added to BrC at concentrations of 0.25, 0.50, 1.00, 1.50, 2.00, and 2.50 wt.%. The results showed that Mg stabilizes the TCP structure and increases the TCP content in final BrC. The initial and final setting times of BrCs increase with higher concentrations of Mg. Although 0.25 wt.% Mg did not change the setting of BrCs significantly, a higher concentration of 1.00 wt.% increased the initial setting time from 4.87 ± 0.38 min to 15.14 ± 0.88 min. Cements with Mg concentrations of 1.5 wt.% and above did not set after 4 h. Mg addition up to 0.5 wt.% did not change the compressive strength; however, higher concentrations decreased it significantly and 2.5 Mg-BrC had the lowest strength of 0.45 ± 0.09 MPs. Together, our results show that Mg can be added up to 1.00 wt.% without any adverse effect on the physical and mechanical properties of BrC.

Genesis of salt deposits in the Jiangling Sag, Jianghan Basin, China: Constraints from H, O, and C isotopes and fluid inclusions of evaporites

Due to Yanshan movement and Himalayan movement, a series of faulted basins were formed in the late Cretaceous and Paleogene, including Shashi Formation of Paleocene in Jiangling sag of Jianghan Basin, when a set of salt lake was deposited. Analysis of lacustrine carbonate rocks in Shashi Formation of Paleocene shows that the δ13CPDB values of carbonate rocks range from −4.8 ‰ to −1.0 ‰, with an average value of −3.3 ‰. The δ18OPDB values ranged from −5.4 ‰ to −0.6 ‰, with an average value of −3.2 ‰. The positive correlation between δ13CPDB and δ18OPDB of the Shashi Formation carbonate rocks indicates that they developed in a relatively closed brackish lake system with obvious evaporation. The homogenization temperature of the upper Shashi Formation in Jiangling sag ranges from 15.3 °C to 51.8 °C, mainly concentrated in 25–30 °C. The δ18O isotope of halite inclusions ranges from −0.8‰ to 9.4‰, with an average of 4.9‰. The δD isotope of halite inclusions ranges from −91.3‰ to −65.0‰ with an average of −79.3‰, which are all lower than the Global Meteoric Water Line. The intense evaporation environment is consistent with the overall drought paleoclimate at that time. The quantitative LA-ICP-MS was used to analyze the composition of the primary inclusion of halite, and it was concluded that the original brine composition was Na-K-Mg-Cl-SO4 system with relative low concentration of Ca2+, high concentration of Mg and SO42- ions and K ions. The high content of Li, B, Br and Rb is related to the intense volcanic activity, deep fluid source and hot spring recharge in Jiangling Depression at that time. Based on carbonate carbon and oxygen isotopes, fluid inclusions temperature and composition, it is concluded that during the Shashi Formation period of Paleocene in Jiangling Sag, the lake basin was well sealed, with high salinity and high temperature, and belonged to a salt lake sedimentary environment, which was favorable for the deposit of salt deposits.

Seasonal variation in mineral concentrations of four marine fish species retained by fishers in Vanga and Msambweni, Kenya

Marine fish is a rich source of minerals in the diet of humans, but seasonal variation in fish mineral concentrations is relatively unstudied. We investigated seasonal mineral concentrations among four marine fish species retained by small scale fishers in Msambweni and Vanga fishing villages in Kenya. The fish species were Siganus sutor (rabbitfish) in Msambweni and Decapterus macarellus (mackerel scad), Sphraena forsteri (bigeye barracuda) and Sphyraena obtusata (obtuse barracuda) in Vanga. Mineral concentrations were quantified in 120 fish specimens (60/season) and their mineral supplementation potential evaluated. The concentrations of Potassium (K), Magnesium (Mg), Zinc (Zn), Iron (Fe) and Iodine (I) were determined using Inductively Coupled Plasma Optical Emission Spectrometry. K, Mg, Zn and I levels in fish samples varied between seasons with higher concentrations during the wet and cool southeast monsoon (SEM) season (April to October). However, Fe concentration was significantly higher during the dry and warm northeast monsoon (NEM) (November to March). S. fosteri recorded the highest concentrations of Mg (72.29 mg/100g in SEM) and Fe (3.63 mg/100g in NEM). S. sutor was the richest source of K (410.21 mg/100g in SEM). These two species also recorded the highest concentration of I (57.6 μg/100g in SEM) while D. macarellus had the highest Zn concentration (5.84 mg/100g in SEM). Mineral concentrations were dependent on fish species as well as season, influencing the mineral intake in Msambweni and Vanga villages.

Elemental concentrations of seven types of green vegetables grown on small-scale farmlands in rural areas of Japan: Differences according to the type and place of production

We collected seven types of green vegetables produced in 11 areas of Japan and analyzed their elemental concentrations. Halogen analyses were performed with and without prior chemical treatment. The most popular type of spinach exhibited the highest concentrations of Mg, K, and Zn, and the lowest concentrations of alkaline earths (Ca and Sr) and halogens (Cl and Br). Japanese mustard spinach, the second most consumed type of spinach in Japan, exhibited the highest concentrations of P, S, Ca, Fe, and Br and adequate amounts of other essential elements. The other five green vegetables had unique elemental concentrations. In particular, radish had the highest concentrations of Ca, Na, and Cl and the lowest concentrations of Mg, P, Cu, and Zn. Leaves and stalks were separately analyzed. Fe, Cu, Zn, and Mn concentrations tended to be higher in leaves, and K, Na, and Rb concentrations were higher in stalks. Halogen (Cl and Br) concentrations in Japanese mustard spinach produced on farmland near the coast were remarkably high, suggesting an effect of sea salt. However, even in green vegetables produced near the coast, halogen uptake clearly differed by production area. The concentrations of Cl and Br in Japanese mustard spinach produced in two coastal areas were very high and were not removed by washing, but were mostly lost after boiling samples from Taneichi for 3[Formula: see text]min. In contrast, there was no difference in Na concentrations among vegetables produced in coastal and inland areas. The concentrations of essential elements such as Mg, Ca, and Fe were clearly higher in green vegetables from small- versus large-scale production areas, perhaps attributable to differences in the farming methods employed.

A Robust Capillary Electrophoresis with Laser-Induced Fluorescence Detection (CE-LIF) Method for Quantitative Compositional Analysis of Trace Amino Acids in Hypersaline Samples.

The search for life in our solar system can be enabled by the characterization of extreme environments representing conditions expected on other planets within our solar system. Molecular abundances observed in these environments help establish instrument design requirements, including limits of detection and pH/salt tolerance, and may be used for validation of proposed planetary science instrumentation. Here, we optimize capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) separations for low limit of detection quantitative compositional analysis of amino acids in hypersaline samples using carboxyfluorescein succinimidyl ester (CFSE) as the amine-reactive fluorescent probe. Two methods were optimized for identification and quantification of proteinogenic amino acids, those with and those without acidic side chains, with limits of detection as low as 250 pM, improving on previous CFSE-amino acid CE-LIF methods by an order of magnitude. The resilience of the method to samples with high concentrations of Mg2+ (>4 M diluted to >0.4 M for analysis) is demonstrated on a sample collected from the salt harvesting facility South Bay Salt Works in San Diego, CA, demonstrating the highest Mg2+ tolerance for CE-LIF methods used in amino acid analyses to date. This advancement enables the rapid and robust analysis of trace amino acids and the search for biosignatures in hypersaline systems.

Catalytic Transfer Hydrogenation Performance of Magnesium-Doped ZrO2 Solid Solutions

This is the first study to investigate the activity of a solid solution containing magnesium ions in a zirconia matrix in the catalytic transfer hydrogenation (CTH) of acetophenone with 2-pentanol. The results have shown that magnesium oxide is very highly active in CTH when physically mixed with zirconia. However, the same concentration of Mg2+ ions (Mg:Zr = 3:97) inserted into a zirconia lattice did not yield high activity in CTH. A higher concentration of Mg2+ ions (5%) was also tested in the two types of systems, i.e., a physical mixture of oxides and a solid solution. The increase in the concentration of Mg2+ ions in the physical mixture led to a pronounced increase in the activity of the system, whereas in the case of the solid solution it led to a slight decrease in activity. The impact of the zirconyl salt used in the synthesis was also examined, but showed little effect on the properties and activity of the systems. The study has also shown that the increase of the concentration of magnesium ions caused a decrease in the m-ZrO2 to t-ZrO2 ratio. Nevertheless, the rate of heating had an even bigger effect on this ratio.

Distribution of Essential and Toxic Elements in Pelecus cultratus Tissues and Risk Assessment for Consumer Health.

Nowadays, the problem of inland water pollution is acute. It is caused by vast industrial growth and agricultural intensification. Concentrations of Cd, Pb, Zn, Cu, Mn, Fe, Mg, and Kwere determined in the muscles, liver, and gonads sabrefish from Rybinsk Reservoir areas with different anthropogenic loads. The tissue samples were analyzed by atomic absorption spectrometry. Heavy metals accumulated more intensively in the body of fish from more polluted areas of the reservoir. Among the analyzed elements, the maximum accumulation levels were found for K, Zn, and Fe and the minimum levels were observed for Cd and Pb. The gonads contained the largest concentration of Cd and Mn, the muscles contained the highest concentrations of Mg, and the other elements mainly accumulated in the liver of sabrefish. The THQ and HI values for all elements did not exceed 1, which suggests that there is no potential non-carcinogenic risk to human health. The target values of carcinogenic risk (TR) for cadmium ranged from 8.32 × 10-6 to 1.22 × 10-4 in the muscles. The increased content of cadmium in the gonads of sabrefish not only poses a risk to human health, but also to the reproduction of this species in the Rybinsk Reservoir.

Evaluating the effect of food components on the digestion of dietary nucleic acids in human gastric juice in vitro.

Nucleic acids (NAs) were recently shown to be digested by pepsin in vitro; however, NAs digestion in human gastric juice in vivo is more complicated because of the complex gastric environment and ingestion of other food components. The purpose of this study was to investigate the digestibility of NAs in real human gastric juices after ingestion of other food components. As a result, DNA digestion was not affected when carbohydrates, proteins, and metal elements were ingested within the recommended dietary intake levels. Separately, protein exerted an inhibitory effect on DNA digestion when the mass ratio of protein:DNA was greater than 40:1. DNA exists in the nucleoprotein, which is closer to the state of DNA in real food, and was digested efficiently in human gastric juice. Meanwhile, DNA digestion was rarely affected even when the concentrations of monovalent ion (Na+) and divalent ions (Mg2+) were as high as 500 and 100 mM, respectively, and high concentration of Mg2+ ranged from 20 to 100 mM accelerated the digestion. In particular, short-stranded DNA (<100 nt) and miRNAs (19 ~ 25 nt) were not obviously degraded in human gastric juice. In conclusion, dietary NAs were digested efficiently and were not affected by other food components in human gastric juice, which may facilitate further digestion and utilization of DNA in the intestinal tract.

Characterization of black and brown Chernobyl “lava” matrices: The formation process reviewed

Detailed understanding about the chemical and physical properties of the Chernobyl “lava” and other radioactive meltdown products is of paramount importance for the support of decommissioning operations and nuclear accident modelling. In this study, we provide new results about the chemical composition and structural properties of the Chernobyl “lava” matrix obtained by electron microprobe analysis and confocal Raman spectroscopy. Based on the compositional data, a principal component analysis (PCA) was conducted to visualize compositional features of the black and brown “lava”, considering data from previous studies. In addition, an inverse modelling approach was performed to assess fractional contributions of construction materials that potentially contributed to the “lava” formation process. The results of the PCA show three varieties of “lava”. Different fractional contributions of UO2-fuel and Zr-cladding indicate the formation of at least two distinct sources of coium melt, respectively, for the black and brown “lava”. For the brown “lava”, the high concentration of Mg is explained by the melting and assimilation of 23% serpentine stemming from the lower reactor shield. The black “lava” shows a high contribution of concrete (43%). Significant differences in the Fe concentration of the black “lava”, as well as macroscopic flow patterns are indicative for a progressive melt formation. However, the cooling of the “lava” occurred relatively fast, forming a metaluminous glass with local variations in the degree of polymerization. Sub-microscopic inclusions of (U1-xZrx)O2 and (Zr1-xUx)O2 solid solutions point to a fractionation of U from an highly oversaturated melt. Based on the new results, the current hypothesis about the “lava” formation process is discussed and reviewed, questioning the existence of one homogenous source of melt and its stratification into layers of black and brown “lava”, before spreading and solidification of the melt.

Effect of Magnesium on Mineral Nutrition, Chlorophyll, Proline and Carbohydrate Concentrations of Sweet Orange (Citrus sinensis cv. Newhall) Plants

Magnesium is an essential nutrient for the growth and development of plants. Its deficiency is becoming a growing concern in many citrus orchards worldwide, adversely affecting numerous functions in plants and limiting their productivity and quality. Three-year-old orange (Citrus sinensis cv. Newhall) plants grafted on Swingle citrumelo (C. paradisi Macf. × Poncirus trifoliata L.) rootstock were irrigated for 63 days with nutrient solutions containing 0, 12, 24, 48, 96, and 192 mg Mg L−1. Thereafter, Mg deficiency-induced changes were investigated in leaf chlorophyll concentration and fluorescence, and in proline and carbohydrate concentration in leaves and roots, as well as in the nutritional status of leaves, stems, and roots. Magnesium concentration in the nutrient solution was positively correlated with the concentration of Mg (leaves, stems, roots), Ca (rootstock’s stem), K (roots), and Fe (leaves, rootstock’s stem), as well as with the total Mg absorption. However, Mg concentration in the nutrient solution was negatively correlated with the concentration of Mn (rootstock’s stem, roots), Ca (leaves, scion’s stems, roots), and Fe (roots), as well as with the total absorption of Mn, Fe, P, K, and Ca. The lower values of the chlorophyll fluorescence parameters were observed by the effect of the highest concentration of Mg. As far as leaf chlorophyll concentration and carbohydrate and proline content of leaves and roots, they were not affected by the Mg treatments. Concluding, this research highlights the significance of Mg management in citrus farming, offering insights into increasing Mg concentrations, understanding root mechanisms in Mg absorption, and suggesting the benefits of fertilization to address Mg deficiency. It emphasizes the importance of careful Mg fertilizer dosages, considering other nutrient interactions, and provides valuable guidance for optimizing Mg nutrition and overall nutrient management in sweet orange trees.

Cathode Nanophosphors

High-current cathodic pulses on an aluminum electrode in solutions containing sufficiently high concentrations of Mg, Ca, Sr, Al, Sc, Y, or La nitrates in a mixture with H3BO3, HF, H3PO4, or H4P2O7 are accompanied by an intense intrinsic luminescence of a number of heavy metals, the ions of which are captured by salt nanofilms and luminescence under the action of hot electrons when are in an environment characteristic of crystal phosphors. The effect of the cathode nanophosphor (CNP) was found in more than 100 systems; photographs are presented for most of the systems. Ga, In, Tl, Ge, Sn, Pb, Mn, Cu, Ag, Cd, Ce, Tb, and Zr ions were activators. The effect of matrix composition on the spectral and kinetic characteristics of the CNP was shown on several examples; a qualitative description of the phenomenon is given, and the prospects for its application to chemical analysis are considered.