Metal Cations Research Articles

Enhanced Gas Barrier and Mechanical Properties of Styrene-Butadiene Rubber Composites by Incorporating Electrostatic Self-Assembled Graphene Oxide @ Layered Double Hydroxide Hybrids.

Rubber composites with a high gas barrier and mechanical properties have received considerable attention due to their potential applications. Constructing complex filler networks in a rubber matrix is an effective strategy to simultaneously enhance the gas barrier and mechanical properties. In this work, graphene oxide layered double hydroxide (GO@LDHs) hybrids were obtained by the electrostatic self-assembly method. A unique interspersed and isolated structure was formed in GO@LDHs hybrids due to the chemical interactions between the functional groups on GO sheets and the metal cations on LDH layers. Subsequently, the GO@LDHs hybrids were incorporated into a styrene-butadiene rubber (SBR) matrix using a green latex compounding method. The results showed that the GO@LDHs hybrids were uniformly embedded in the SBR matrix, constructing an overlapped filler network and forming physical bonding points that reduced the free volume of the composites. The electrostatic interactions between GO@LDHs hybrids facilitated energy dissipation during stretching, thereby improving the mechanical performance of the rubber composites. More importantly, the N2 gas permeability and fracture toughness of GO@LDHs/SBR composites decreased by 52.2% and increased by 845%, respectively, compared to those of a pure SBR matrix. The construction of GO@LDHs hybrids offers new insights for designing rubber composites with a high gas barrier and mechanical properties.

Fluorescence Carbon Dots from Blood-Berries for Sensing Cr6+ Ions in Water and Application in White Light Emitting Diode.

Conventional techniques for identifying heavy metal ions in water are laborious and time-consuming. Therefore, it is necessary to create innovative sensing technologies that can detect with greater sensitivity and speed. Although there have been reports of optical-based assays utilising fluorescent nanomaterials, these assays usually rely on variations in signal strength. However, this approach has significant drawbacks when it comes to environmental monitoring. Fluorescence carbon dots (CDs) have been prepared by facile synthesis from Blood berries. A homemade heavy metal optical detector is constructed to accurately identify heavy metal ions, exclusively Cr6+ ions in a water medium. Their optical emission signature varies based on the specific chromium ions in solution, and the emission intensity also changes depending on its concentration. The quenching behaviour is attributed to the interaction between the metallic cations and the fluorescent surface states of the carbon dots. Another application is the encapsulation of CDs in PVDF polymer to form a flexible film and use it as a phosphor for LED conversion.

Unveiling the Role of Surface Self‐Reconstruction of Metal Chalcogenides on Electrocatalytic Oxygen Evolution Reaction

AbstractTransition metal chalcogenides are an important class of electrocatalysts with broad application prospects in alkaline oxygen evolution reactions. Many researchers are focusing on the in situ conversion of metal cations in catalysts, but have rarely considered the contribution of oxidation, leaching, and re‐absorption of chalcogenides to the catalytic activity. Herein, multiple characterization approaches are used to monitor the evolution mechanism and origin CoTe@CoS‐electrocatalyzed oxygen evolution reaction (OER) activity. The research results reveal that the electro‐oxidative dissolution of Te and S on the electrode surface forms TeO32− and SO32−, which are adsorbed on the electrode surface. Moreover, TeO32− and SO32− species will further transform into TeO42− and SO42−. As expected, the extra addition of mixed tellurite and sulfate ions to the Co (OH)2 electrolyte produces a synergistic effect that can significantly boost OER activity. Selenites reveal the analogous effect, indicating that the adsorption of chalcogenates the electrode surface has a universal effect on improving OER performance. The findings of this work provide unique insights into the species conversion of catalytic materials and the mechanism of enhancing catalytic activity during OER processes.

Room-Temperature Possible Current-Induced Transition in Ca2RuO4 Thin Films Grown Through Intercalation-Like Cation Diffusion in the A2BO4 Ruddlesden-Popper Structure.

Cation deficiency tuning is a central issue in thin-film epitaxy of functional metal oxides, as it is typically more difficult than anion deficiency tuning, as anions can be readily supplied from gas sources. Here, highly effective internal deficiency compensation of Ru cations is demonstrated for Ca2RuO4 epitaxial films based on diffusive transfer of metal cations in the A2BO4 Ruddlesden-Popper lattice from solid-phase cation sources. Through detailed structural characterization of Ca2RuO4/LaAlO3 (001) thin films grown with external cation sources by solid-phase epitaxy, the occurrence of intercalation-like, interstitial diffusion of La cations (from the substrates) in the A2BO4 structure is revealed, and that of Ru cations is also suggested. Relying on the interstitial-type diffusion, an optimized Ru deficiency compensation method, which does not induce the formation of Can +1RunO3 n +1 Ruddlesden-Popper impurity phases with higher n, is proposed for Ca2RuO4 epitaxial films. In the Ca2RuO4/LaAlO3 (001) thin films grown with Ru deficiency compensation, record-high resistivity values (102-10-1 Ω cm) and a large (more than 200 K) increase in the temperature range of the nonlinear transport properties are demonstrated by transport measurements, demonstrating the possible advantages of this method in the control of the current-induced quantum phase transition of Ca2RuO4.

Effect of ion-specific water structures at metal surfaces on hydrogen production

Water structures at electrolyte/electrode interfaces play a crucial role in determining the selectivity and kinetics of electrochemical reactions. Despite extensive experimental and theoretical efforts, atomic-level details of ion-specific water structures on metal surfaces remain unclear. Here we show, using scanning tunneling microscopy and noncontact atomic force microscopy, that we can visualize water layers containing alkali metal cations on a charged Au(111) surface with atomic resolution. Our results reveal that Li+ cations are elevated from the surface, facilitating the formation of an ice-like water layer between the Li+ cations and the surface. In contrast, K+ and Cs+ cations are in direct contact with the surface. We observe that the water network structure transitions from a hexagonal arrangement with Li+ to a distorted hydrogen-bonding configuration with Cs+. These observations are consistent with surface-enhanced infrared absorption spectroscopy data and suggest that alkali metal cations significantly impact hydrogen evolution reaction kinetics and efficiency. Our findings provide insights into ion-specific water structures on metal surfaces and underscore the critical role of spectator ions in electrochemical processes.

Exploring electrochemical kinetic behaviors and interfacial charge transfer of pure and Ni-doped ZnFe2O4 nanoparticles-based sensing nanoplatform for ultra-sensitive detection of chloramphenicol

ZnFe2O4 (ZFO) nanomaterial was doped with a divalent transition metal cation of Ni2+ (NixZn1-xFe2O4, x=0, 0.2, 0.4, and 0.8) and characterized by various analytical techniques. Powder X-ray diffraction revealed the formation of a single-phase cubic spinel structure, while the stabilization of crystal structure for Ni2+-doped samples was observed. The average crystalline size, d-spacing, and lattice parameters increased with increasing in Ni2+ concentration within NixZn1-xFe2O4, due to differences in the ionic radius, the cation distribution at A-B sites, and the creation of surface oxygen vacancies within ZFO structure. From electrochemical measurements, NixZn1-xFe2O4-based electrodes showed excellent enhancements in charge transfer ability and conductivity with the highest rate constant (0.018 ms−1), the lowest peak-to-peak separation (206 mV), the lowest Rct (118 Ω), and the largest electrochemical active area (0.248 cm2), compared to that of bare SPE. Among them, Ni0.8Zn0.2Fe2O4/SPE provided outstanding electrochemical behaviors and achieved the best sensing performance with the widened concentration linear range from 0.25 to 50 μM and a rather low detection limit of 0.2 μM for chloramphenicol detection. The most important reason for this positive advance comes from the unique synergistic effects of Ni doping into the ZFO host structure. The excellent enhancements in adsorption capacity (Г) (1.4 times higher), number of oxygen vacancies, charge transfer rate constant (approximately 1.15 times higher), and catalytic rate constant (30 times greater) were recorded at Ni-doped ZFO-based electrodes, compared to pure ZFO-based electrode. Furthermore, the detailed hypotheses and possible mechanisms explaining these impressive enhancements were explored. Our work provides insight into the correlation between the Ni-doping and electrochemical characteristics, which has implications for tailoring the electrochemical performance of spinel ferrites across diverse applications and the design of novel spinel ferrite nanomaterials.

Click Chemistry Derived Hexa-ferrocenylated 1,3,5-Triphenylbenzene for the Detection of Divalent Transition Metal Cations.

The 1,3-dipolar cycloaddition reaction (click chemistry approach) was employed to create a hexa-ferrocenylated 1,3,5-triphenylbenzene derivative. Leveraging the presence of metal-chelating sites associated with 1,2,3-triazole moieties and 1,4-dinitrogen systems (ethylenediamine-like), as well as tridentate chelating sites (1,4,7-trinitrogen, diethylene triamine-like) systems, the application of this molecule as a chemosensor for divalent transition metal cations was investigated. The interactions were probed voltammetrically and spectrofluorimetrically against seven selected cations: iron(II) (Fe2+), cobalt(II) (Co2+), nickel(II) (Ni2+), copper(II) (Cu2+), zinc(II) (Zn2+), cadmium(II) (Cd2+), and manganese(II) (Mn2+). Electrochemical assays revealed good detection properties, with very low limits of detection (LOD), for Co2+, Cu2+, and Cd2+ in aqueous solution (0.03-0.09 μM). Emission spectroscopy experiments demonstrated that the title compound exhibited versatile detection properties in solution, specifically turn-off fluorescence behavior upon the addition of each tested transition metal cation. The systems were characterized by satisfactory Stern-Volmer constant values (105-106 M-1) and low LOD, especially for Zn2+ and Co2+ (at the nanomolar concentration level).

The superior adsorption capacity of biogenic α-Mn2O3 in comparison to chemogenic α-Mn2O3 for five divalent heavy metal cations and the adsorption mechanism of biogenic α-Mn2O3: Experimental and DFT investigations

Manganese oxides play a crucial role in the adsorption of heavy metals in the environment. However, there is currently a lack of information regarding the comparative adsorption efficiency of heavy metals between biogenic and chemogenic manganese oxides. In this work, we compared the adsorption performance of biogenic and chemogenic α-Mn2O3 towards Pb(II), Cd(II), Cu(II), Zn(II) and Ni(II). Mineral characterization analyses revealed that biogenic α-Mn2O3 exhibited a polycrystalline nature, whereas chemogenic α-Mn2O3 displayed a monocrystalline nature with a lower impurity content compared to biogenic α-Mn2O3. Under acidic conditions, biogenic α-Mn2O3 demonstrated a significantly higher adsorption capacity, ranging from 3 to 6 times greater than its chemogenic counterpart, within an initial heavy metal concentration range of 0.2–1.0 mM. This superiority can be attributed to the presence of more abundant functional groups and a greater content of hydroxyl O species on the surface of biogenic α-Mn2O3 in comparison to chemogenic α-Mn2O3. During the adsorption process of biogenic α-Mn2O3, there were observed ionic exchanges between Mn(II) and these cations. More importantly, biogenic α-Mn2O3 bound with these cations probably through the formation of -O/OH/S complexes. The adsorption selectivity of biogenic α-Mn2O3 towards the five heavy metals was experimentally determined to follow the order of Ni(II) > Pb(II) > Cu(II) > Zn(II) > Cd(II). The electronic interaction between biogenic α-Mn2O3 and these cations indicated that Ni(II), Pb(II) and Cu(II) were more likely to share electrons with O atoms on the surface of biogenic α-Mn2O3 compared to Zn(II) and Cd(II).

New fibrous carboxyl cation exchangers for sorption cations of heavy and non-ferrous metals from water

New fibrous carboxyl cation exchangers FIBAN were synthesized by the method of graft copolymerization to polypropylene staple fibers of acrylic acid and various bifunctional comonomers (divinylbenzene – DVB, ethyleneglycoldimethacrylate – EGDM, methylene-bis-acrylamide – MBAA). Sorption properties of the fibers towards cations of heavy and non-ferrous metals (Cо2+, Ni2+, Zn2+, Cd2+, Cu2+ и Pb2+) were studied on the model solutions in the dynamic regime. The dynamic activity of the crosslinked sorbents towards Cu2+ and Pb2+ ions is higher compared to fibrous analogues FIBAN Х-1, FIBAN Х-2, FIBAN К-6М, FIBAN К-5, VION КN-1. The best sorbent for lead ions between the crosslinked fibers is the fiber with EGDM. The fiber with MBAA has a higher affinity towards the cations of Ni2+, Zn2+, Cd2+ and Cа2+, which increases with the increasing of the degree of crosslinking by MBAA. Studying the fibers by the methods of Fourier-transform IR-spectroscopy, scanning electron microscopy, analyzing of the chemical oxygen demand in water extracts and determination of the equivalent moisture capacity coefficient coefficient demonstrated that the crosslinking by MBAA provides a stable structure of the sorbent. The high stability of the crosslinked structure combined with the high ion exchange capacity near 7 mEq/g and dynamic activity towards the cations of Pb2+, Zn2+, Cd2+ и Cа2+ makes the fibrous carboxyl sorbent with MBAA safe and perspective for drinking water purification.

Design of Point Charge Models for Divalent Metal Cations Targeting Quantum Mechanical Ion–Water Dimer Interactions

Divalent metal cations are of vital importance in biochemistry and materials science, and their structural and thermodynamic properties in aqueous solution have often been used as targets for the development of ion models. This study presented a strategy for designing nonbonded point charge models of divalent metal cations (Mg2+ and Ca2+) and Cl− by targeting quantum mechanics (QM)-based ion–water dimer interactions. The designed models offered an accurate representation of ion–water interactions in the gas phase and showed reasonable performance for non-targeted properties in aqueous solutions, such as the ion–water oxygen distance (IOD), coordination number (CN), and density and viscosity of MgCl2 and CaCl2 solutions at low concentrations. Our metal cation models yielded considerable overestimates of the hydration free energies (HFEs) of the ions, whereas the Cl− model displayed good performance. Together with the overestimated density and viscosity of the salt solutions, these results indicated the necessity of re-optimizing ion–ion interactions and/or including polarization effects in the design of ion models. The designed Mg2+ model was capable of maintaining the crystal metal-binding networks during MD simulation of a metalloprotein, indicating great potential for biomolecular simulations. This work highlighted the potential of QM-based ion models to advance the study of metal ion interactions in biological and material systems.

Corrosion behavior and strengthening mechanism of Ni-Cu alloy coating on NdFeB magnets

In this paper, the pulse-reverse current electroplating technique was utilized to deposit nickel–copper (Ni-Cu) alloy coatings on the surface of neodymium magnets (NdFeB). Compared with the nickel (Ni) coating, the corrosion resistance of the nickel–copper alloy coating has been significantly improved. Additionally, the results show that alloying can effectively prolong the incubation period of pitting nucleation and improve the self-healing ability of coating. The structure and microstructure of the coating show that the surface of the nickel–copper coating is flat and the grains preferentially grow along the (111) close-packed surface, which also makes the coating to have higher densification and significantly reduces the number of self-corrosion sites and corrosion tendency of the coating. The lower binding energy copper(I) oxide (Cu2O) produced by nickel–copper coatings at the initial corrosion stage can reduce the formation of metal cation holes and prolong the incubation period of pitting corrosion. After pitting formation, the corrosion products copper(I) oxide and dicopper chloride trihydroxide (Cu2(OH)3Cl) of copper (Cu) in the pitting hole have a certain hindrance to corrosion and are conducive to promoting passive reconstruction, which is an important reason for higher self-healing ability and higher corrosion resistance of the nickel–copper alloy coating.

Gas-Phase Structures of Fucosylated Oligosaccharides: Alkali Metal and Halogen Influences.

Fucosylated carbohydrate antigens play critical roles in physiology and pathology with function linked to their structural details. However, the separation and structural characterization of isomeric fucosylated epitopes remain challenging analytically. Here, we report for the first time the influence of alkali metal cations (Li+, Na+, K+, Rb+, and Cs+) and halogen anions (Cl-, Br-, and I-) on the gas-phase conformational landscapes of common fucosylated trisaccharides (Lewis A, X, and H types 1 and 2) and tetrasaccharides (Lewis B and Y) using trapped ion mobility spectrometry coupled to mass spectrometry and theoretical calculations. Inspection of the mobility profiles of individual standards showed a dependence on the number of mobility bands with the oligosaccharide and the alkali metal and halogen; collision cross sections are reported for all of the observed species. Results showed that trisaccharides (Lewis A, X, and H types 1 and 2) can be best mobility resolved in the positive mode using the [M + Li]+ molecular ion form (baseline resolution r ≈ 2.88 between Lewis X and A); tetrasaccharides can be best mobility resolved in the negative mode using the [M + I]- molecular ion form (baseline separation r ≈ 1.35 between Lewis B and Y). The correlation between the number of oligosaccharide conformers as a function of the molecular ion adduct was studied using density functional theory. Theoretical calculations revealed that smaller cations can form more stable structures based on the number of coordinations, while larger cations induced greater oligosaccharide reorganizations; candidate structures are proposed to better understand the gas-phase oligosaccharide rearrangement trends. Inspection of the candidate structures suggests that the interplay between ion size/charge density and molecular structure dictated the conformational preferences and, consequently, the number of mobility bands and the mobility separation across isomers. This work provides a fundamental understanding of the gas-phase structural dynamics of fucosylated oligosaccharides and their interaction with alkali metals and halogens.

Revealing the degradation pathways of layered Li-rich oxide cathodes.

Layered lithium-rich transition metal oxides are promising cathode candidates for high-energy-density lithium batteries due to the redox contributions from transition metal cations and oxygen anions. However, their practical application is hindered by gradual capacity fading and voltage decay. Although oxygen loss and phase transformation are recognized as primary factors, the structural deterioration, chemical rearrangement, kinetic and thermodynamic effects remain unclear. Here we integrate analysis of morphological, structural and oxidation state evolution from individual atoms to secondary particles. By performing nanoscale to microscale characterizations, distinct structural change pathways associated with intraparticle heterogeneous reactions are identified. The high level of oxygen defects formed throughout the particle by slow electrochemical activation triggers progressive phase transformation and the formation of nanovoids. Ultrafast lithium (de)intercalation leads to oxygen-distortion-dominated lattice displacement, transition metal ion dissolution and lithium site variation. These inhomogeneous and irreversible structural changes are responsible for the low initial Coulombic efficiency, and ongoing particle cracking and expansion in the subsequent cycles.

MoⅣ boosted carrier density of MoO3-X for surface-enhanced Raman spectroscopy

Molybdenum oxides (MoO3-X) with the same surface plasmon resonance (SPR) effect as Au/Ag, and occupies an irreplaceable value in SERS detections. MoO3-X SERS substrates with oxygen-rich defects tend to show better SERS performance, but the preparation and characterization of tunable O defects remain challenging. It cannot be ignored that the oxidation state of metal cations is also influenced by O defects. Here, a series of MoO3-X SERS sensors with regulable Mo valence state were fabricated using magnetron sputtering technology. By changing the Mo sputtering power and the O2/Ar2 ratio, the Mo/O element ratio of the substrate can be easily regulated to readjust the O defects. The X-ray Photoelectron Spectroscopy (XPS) and Raman spectra were performed to investigate the change and related relationship between Mo mixed valence state and SERS sensitivity. The abundant incompletely coordinated electrons produced by low valence MoⅣ act as free carriers, increasing the free carrier density of MoO3-X substrates, which is beneficial for the SERS effect. It has also been proven by Hall effect measurement. The SERS measurement shows that the enhancement factor (EF) reached 3.70 × 105, which is exceedingly close to Au/Ag. The MoO2.5 substrate also exhibited a repeatable and consistent response, high stability, and repeatability, which proves the splendid application potential in complex environments.

Sorption-Desorption of Rare-Earth Metal Cations by Ferromanganese Crusts of the Govorov Guyot, Magellan Seamounts, Pacific Ocean

Sorption-Desorption of Rare-Earth Metal Cations by Ferromanganese Crusts of the Govorov Guyot, Magellan Seamounts, Pacific Ocean

Remarkable chemical adsorption and catalysis of 3D self-supporting Zn-doped NiCo2O4 nanowires for high-performance lithium-sulfur batteries

Lithium-sulfur batteries are one of the most potential next-generation energy storage systems with high theoretical energy density and low cost. However, the lithium polysulfides (LiPSs) dissolution and shuttle effect limit their commercial application. Herein, the Zn-doped NiCo2O4 nanowires grown on carbon cloth (ZNCOCC) are prepared by hydrothermal method and as sulfur host. ZNCO nanowires consisting of stacked nanoparticles and abundant mesopores were grown vertically on carbon fibers. The mesoporous structure of ZNCOCC provides more space to accommodate sulfur and its volume change during charging and discharging, is conducive to electrolyte infiltration and maintains strong adsorption of LiPSs to ensure fast ion transport kinetics. The ZNCOCC displays higher Co3+/Co2+ and Ni3+/Ni2+ ratio compared to NCOCC, and the high-valent metal cations can provide more unsaturated electron orbitals for S binding, causing high adsorption of LiPSs. Density functional theory calculations demonstrate that the Zn doping significantly reduces the band gap, improves the conductivity and increases the LiPSs adsorption energy of NCO. The ZNCOCC/Li2S8 displays a high specific capacity of 1184 mAh g−1 (0.1 C) and a low decay of 0.07 %/cycle after 500 cycles (2 C). This research reveals the rational design of a doped bimetal oxide nanostructure for the improvement of lithium-sulfur batteries.

Exploring the effects of the alkaline earth metal cations on the electronic structure, photostability and radiation hardness of lead halide perovskites

The growing interest to the application of perovskite solar cells (PSC) in aerospace requires great attention to the design of new absorber materials with enhanced photostability and radiation hardness. We addressed this challenge through the B-site engineering by partial replacing of Pb2+ in the complex halides with Ca2+, Sr2+, and Ba2+. Change in the material electronic properties suggests the incorporation of the substituent cations in the perovskite lattice. However, when the loading of alkaline earth halides is high, they tend to segregate to the film surface and grain boundaries. The modification of MAPbI3 and Cs0.12FA0.88PbI3 by replacing a 1% of Pb2+ with alkaline earth metal cations resulted in improvements in the photostability and radiation hardness under exposure to gamma rays and electrons beam. Depending on the material formulation, it was possible to mitigate the photochemical and radiation-induced Pb0 formation and the univalent cation phase segregation. The best of the designed perovskite absorbers could successfully tolerate high doses of gamma rays (5.5 MGy) and electron fluences (3 × 1016 e/cm2), thus outperforming significantly the non-modified material. These findings feature the incorporation of alkaline earth metal cations as a promising approach for the development of PSC with enhanced radiation hardness for aerospace applications.

A facile strategy for synthesis of flower-like FeNiS2 nanocomposite via integration of binary metal-organic framework and metal sulfide for enhanced electrocatalytic oxygen evolution reaction

Researchers are looking into boosted functional materials to address the rising demand for enhanced energy storage and efficient catalysts in producing and storing sustainable energy. Here, we report the development of an integrated binary metallic FeNi metal-organic framework (MOF) through a unique method termed reductive electrosynthesis. This MOF provides customized catalytic sites inside a highly porous material by connecting metal cations via 2-amino terephthalic acid connectors. However, the poor electrical conductivity and stability of pristine MOFs have made their practical implementation difficult. A thin FeNiS2/nickel foam (NF) nanocomposite based on the precursor and self-sacrificed FeNi-MOF template was developed to get beyond these restrictions. In addition to improving electrical conductivity, this unique structure supports FeNi-MOF porous structure. As a result, the outstanding functional electrocatalytic performance of FeNiS2/NF on oxygen evolution reaction in alkaline media was observed at low overpotential of ηj10 = 280 mV and a tafel slope of 35 mV/dec. This study provides a feasible way to produce highly stable and active nonprecious electrocatalysts for commercial water electrolysis applications.

ценка риска формирования у детей вторичного иммунодефицита в условиях контаминации биосред алюминием и полиморфизма гена клеточной гибели FAS rs1159120 и антигенраспознающего гена толл-подобного рецептора TLR4 rs1927911

Secondary immunodeficiency remains an incompletely understood medical problem, and despite a significant number of international and scientific studies, there is no complete picture of the causes and consequences of this pathology. Metal cations have been proven to participate in the formation of acquired immunodeficiency. In particular, aluminum properties as an immune suppressor have been established and its targets in the body have been identified in case aluminum was present in biological media. However, no evaluations have been accomplished so far as regards the role of specific point genetic changes, that is, polymorphisms in the genes of immune system compartments that determine the risk of negative effects caused by contamination with metal cations, including aluminum. It is quite relevant to search and substantiate immunogenetic markers to create an indicator system for diagnostics and prevention of secondary immunodeficiency states in children associated with aluminum contamination in biological media. We examined 97 preschool children exposed to elevated levels of airborne aluminum (in an area influenced by a metallurgic production). The study groups were divided depending on either presence or absence of secondary immunodeficiency as immune system pathology (common variable immunodeficiency D83). Several markers of the immune system were evaluated: aluminum-specific IgG, CD3+, CD4+, CD8+, CD127-, CD95+, CD284+, and phagocytic activity; we also evaluated polymorphism of TLR4 A8595G (rs1927911) and FAS C14405T (rs1159120) genes of innate and acquired immunity. According to the results obtained by examining biological media composition, children with secondary immunodeficiency had 1.8 times higher aluminum levels in urine (0.0095 ± 0.0014 vs. 0.0054 ± 0.0009 mg/dm3, reference range < 0.0075 mg/dm3) as opposed to their conditionally healthy peers. We established an authentic inverse dependence between the expression level of the main CD clusters (CD3+: r = -0.38; CD4+: r = -0.39; CD8+: r = -0.26) as well as indicators of phagocytic activity (r = -0.22–0.23) and the level of aluminum contamination in biological media (urine). Expression of T-mature lymphocyte clusters was found to be inhibited by 1.3–3.1 times (including T-helper, effector T-lymphocytes, NK-killers, regulatory lymphocytes) and we also detected some changes in expression of specific immunoglobulin of IgG class to aluminum. All this results in an unacceptable level of relative risk (RR = 1.23–1.63) of developing secondary immunodeficiency against increased frequency of allele C and genotype CC of FAS gene (rs1159120) by 1.2 and 1.5 times respectively, as well as minor allele G of TLR4 gene (rs1927911) by 1.8 times relative to the comparison group (OR = 4.05; CI: 1.41–11.59; p = 0.006; RR = 1.23; CI: 1.02–1.48) and (OR = 2.01; CI: 1.04–3.91; p = 0.037; RR = 1.64; CI:1.46–1.94). Toll-dependent and FAS-dependent mechanism of this risk is associated with aluminum contamination. It is recommended to use a combination of immune and genetic markers as indicator ones when evaluating the immune system state, in order to prevent the risk (RR = 1.23–1.63) of secondary immunodeficiency associated with aluminum contamination in biological media.

Assessing risks of secondary immunodeficiency in children with aluminum contamination in biological media and polymorphism of the cell death gene FAS rs1159120 and the antigen-recognizing gene of the toll-like receptor TLR4 rs1927911

Secondary immunodeficiency remains an incompletely understood medical problem, and despite a significant number of international and scientific studies, there is no complete picture of the causes and consequences of this pathology. Metal cations have been proven to participate in the formation of acquired immunodeficiency. In particular, aluminum properties as an immune suppressor have been established and its targets in the body have been identified in case aluminum was present in biological media. However, no evaluations have been accomplished so far as regards the role of specific point genetic changes, that is, polymorphisms in the genes of immune system compartments that determine the risk of negative effects caused by contamination with metal cations, including aluminum. It is quite relevant to search and substantiate immunogenetic markers to create an indicator system for diagnostics and prevention of secondary immunodeficiency states in children associated with aluminum contamination in biological media. We examined 97 preschool children exposed to elevated levels of airborne aluminum (in an area influenced by a metallurgic production). The study groups were divided depending on either presence or absence of secondary immunodeficiency as immune system pathology (common variable immunodeficiency D83). Several markers of the immune system were evaluated: aluminum-specific IgG, CD3+, CD4+, CD8+, CD127-, CD95+, CD284+, and phagocytic activity; we also evaluated polymorphism of TLR4 A8595G (rs1927911) and FAS C14405T (rs1159120) genes of innate and acquired immunity. According to the results obtained by examining biological media composition, children with secondary immunodeficiency had 1.8 times higher aluminum levels in urine (0.0095 ± 0.0014 vs. 0.0054 ± 0.0009 mg/dm3, reference range < 0.0075 mg/dm3) as opposed to their conditionally healthy peers. We established an authentic inverse dependence between the expression level of the main CD clusters (CD3+: r = -0.38; CD4+: r = -0.39; CD8+: r = -0.26) as well as indicators of phagocytic activity (r = -0.22–0.23) and the level of aluminum contamination in biological media (urine). Expression of T-mature lymphocyte clusters was found to be inhibited by 1.3–3.1 times (including T-helper, effector T-lymphocytes, NK-killers, regulatory lymphocytes) and we also detected some changes in expression of specific immunoglobulin of IgG class to aluminum. All this results in an unacceptable level of relative risk (RR = 1.23–1.63) of developing secondary immunodeficiency against increased frequency of allele C and genotype CC of FAS gene (rs1159120) by 1.2 and 1.5 times respectively, as well as minor allele G of TLR4 gene (rs1927911) by 1.8 times relative to the comparison group (OR = 4.05; CI: 1.41–11.59; p = 0.006; RR = 1.23; CI: 1.02–1.48) and (OR = 2.01; CI: 1.04–3.91; p = 0.037; RR = 1.64; CI:1.46–1.94). Toll-dependent and FAS-dependent mechanism of this risk is associated with aluminum contamination. It is recommended to use a combination of immune and genetic markers as indicator ones when evaluating the immune system state, in order to prevent the risk (RR = 1.23–1.63) of secondary immunodeficiency associated with aluminum contamination in biological media.