Concentrations Of Inorganic Components Research Articles

Robust interface for O3-type layered cathode towards stable ether-based sodium-ion full batteries

Developing a robust cathode-electrolyte interface (CEI) is crucial for stable layered cathode in sodium-ion batteries (SIBs). A CEI based on ester electrolytes often exhibit poor stability and robustness, which cannot address the issues of structural collapse and material dissolution in layered cathodes. However, there are few reports on constructing a stable CEI for layered cathode based on ether electrolytes. Here we develop a robust CEI for O3-type cathode via DME solvent, which enables a long-term stability of full SIBs. The results indicate that unique decomposition process of DME yields favorable organic component (e.g. RCH2ONa) and high content of inorganic components (e.g. NaF and Na2CO3) in the CEI, which is quite different from ester electrolyte, improving Na+ diffusion kinetic and interfacial stability. Notably, the O3-NaNi0.5Mn0.5O2||Na cell with the designed electrolyte demonstrates outstanding stability up to 500 cycles. Furthermore, the full cell exhibits remarkable cycling performance with a capacity retention of 85% over 200 cycles. This work provides an opportunity for stable operation of layered cathode materials via inexpensive ether electrolytes.

Polyaromatic hydrocarbons of small reservoirs of the Tomsk region

Relevance. The assessment of the state of natural waters includes the determination of a number of physico-chemical indicators, on the basis of which various indices and classifications are developed. However, they do not take into account a number of pollutants that have a significant impact on the state of the reservoir, for example, polyaromatic hydrocarbons. The article considers some aspects of determining priority pollutants, which include polyaromatic hydrocarbons, according to environmental hazard criteria: toxicity, carcinogenicity, prevalence, frequency of occurrence, source of origin (anthropogenic or natural). Hydrochemical parameters such as pH, dissolved oxygen content, biological oxygen consumption (BPK5), and ion content are taken into account to determine water quality. An attempt was made to assess the impact of polyaromatic hydrocarbons on the ecological state of water bodies and to take into account their contribution to changes in the values of the water pollution index. All these data prove the relevance of the study. Aim. To establish the composition of polyaromatic hydrocarbons in the surface waters of small reservoirs of the Tomsk region to assess anthropogenic load and to show the relationship with the indices of natural water quality. Methods. Extraction, liquid adsorption chromatography, high-performance liquid chromatography, capillary electrophoresis, amperometry, titrimetry. Results. Small lakes of the Tomsk region were studied for the content of 13 polyaromatic hydrocarbons. The authors have carried out the identification by high-performance liquid chromatography with fluorimetric detection. The total content of polyaromatic compounds in the studied surface water samples varies from 0.37 to 0.54 mcg/l. In the polyaromatic hydrocarbons mixture in aqueous samples, there is an increased content of light 2–3 nuclear polyarenes with better solubility (naphthalene, fluorene and phenanthrene), as well as benz[a]anthracene. The content of inorganic components represented by cations and anions does not exceed the maximum permissible concentrations. The water pollution index was calculated; all lakes are moderately polluted, closer to polluted. The paper demonstrates the dependence of the water pollution index coefficient on the content of high-molecular polyaromatic hydrocarbons and the ratio of high-molecular to low-molecular polyaromatic hydrocarbons. It is shown that the higher the value of the water pollution index coefficient, the higher the proportion of difficult-to-oxidize components in surface waters.

Functionalization of boron nitride with poly(catechol-polyamine) and bis(γ-triethoxysilylpropyl)tetrasulfide for preparing epoxy nanocomposites with enhanced thermal conductivity

Hexagonal boron nitride (hBN) has garnered significant interest as inorganic thermally conductive material in electronic packaging due to its high-efficiency thermal management capability and electrical insulation properties. However, the relatively inert chemical environment of the BN surface hinders phonon transfer at the interface. Additionally, the high content of inorganic components in the matrix leads to the deterioration of the composite’s mechanical properties. In this research, h-BN surface is modified using poly(catechol-polyamine) (PCPA) and bis (γ-triethoxysi-lylpropyl)tetrasulphide (Si69) (denoted as BN-PCPA-Si69). The noncovalent PCPA modification protects the endothermic properties of BN, Si69 provides covalent bonding between thermally conductive fillers and bisphenol A-type epoxy resin (Ep), and the interfacial compatibility between BN and epoxy resin is improved. The heat conductivity of final BN/Ep composite achieved 0.817 W/(m·K) containing 30 wt% BN. Correspondingly, the heat conductivity of the composite (mBN/Ep) achieved 0.881 W/(m·K) containing 30 wt% BN-PCPA-Si69. Compared to pure epoxy resin (0.200 W/(m·K), the thermal conductivity (TC) of the mBN/Ep composite increased by 364% while maintaining good electrical insulation properties. The proposed BN surface functionalization approach has potential applications in fields such as microelectronic packaging, where materials need to balance high thermal conductivity and electrical insulation.

Physicochemical and structural characteristics of hybrid nanocomposites based on branched polyimide with a low content of inorganic component

The series of organic-inorganic hybrid nanocomposites based on branched polyimide matrix and with different amounts of tetraethoxysilane (TEOS) (5, 20, and 50 wt.% of the initial polyamic acid mass) were synthesized and studied using nitroxyl paramagnetic probe, measuring dielectric permittivity, X-ray structural analysis and optical microscopy. It was shown that in some cases the introduction of inorganic component is accompanied by a decrease in the segmental mobility of polyimide matrix as a result of the partial immobilization of organic macrochains during the formation of inorganic microregions. In the presence of inorganic component, a weak dependence of the polymer permeability on the content of the organic component in the system is observed, also the specific density changes little with an increase in TEOS content. Extreme changes in the segmental mobility and dielectric permittivity of the branched matrix formed in the presence of 5 wt% TEOS were found compared to systems of other compositions. This can be caused to a large extent by structural changes in the system. At a low content of TEOS occurs significant «loosening» of organic matrix, a sharp decrease in the dielectric constant and a significant increase in the segmental mobility of the polyimide matrix. Small angle X-ray scattering diffractograms demonstrate drastic changes in polyimide composite heterogeneity in the presence of 5 wt.% TEOS content. According to the optical microscopy data, the introduction of TEOS into polyimide is accompanied by the formation of microaggregates of inorganic nanoparticles in the system, the number and average size of which depend on the SiO2 content and looks most homogeneous at a low TEOS content.

Measurement of nanocomposite scintillators by terahertz time domain spectroscopy.

Nanocomposite scintillators are expected to combine the advantages of inorganic and plastic scintillators, such as high detection efficiency, high light yield, fast decay time, low cost, and ease of processing. They are currently the forefront and hot field of scintillator research. In this study, a non-destructive method was developed for measuring the content of inorganic components in nanocomposite scintillators by terahertz time-domain spectroscopy. The complex refractive index of B a F 2 nanocomposite scintillators with different mass contents was measured in the terahertz band. As the mass content of B a F 2 nanoparticles increases, the refractive index and extinction coefficient of B a F 2 nanocomposite scintillators also gradually increase in the terahertz band. By combining the effective medium theory, the expected mass content was obtained, proving the feasibility of this measuring method.

Hydrogels and their composites based on sulfo-containing acrylates: preparation, properties, and proton conductivity

This work presents a method for the synthesis of multifunctional hydrogels based on polymer framework obtained by UV-initiated polymerization of the acrylic monomers (acrylamide, acrylonitrile, and sulfo-group-containing monomer (3-sulfopropyl acrylate potassium salt, 2-acrylamido-2-methylpropane sulfonic acid, and sodium styrene sulfonate)) in the presence of N,N′-methylenebisacrylamide as a cross-linking agent. Composite polymer/silica nanogels have been created in situ using a TEOS-based sol–gel system and the above-mentioned polymeric matrices. The synthesized material characteristics such as composition, morphology, and thermal stability were explored with FTIR, SEM, and DCS. In addition, the effect of temperature, inorganic component content, sulfo-group-containing monomer to proton conductivity and water uptake have been explored. The obtained hydrogels possess proton conductivity up to 19 mSm/cm with potential implying for application in electrochemical devices and superabsorbent material. This method is user-friendly and cost-efficient, and proceeds in an aqueous environment under atmospheric conditions without the use of heavy metal catalysts.

Reinterpreting the correlation between cycling stability of Ni-rich layered oxide cathode and the charging cut-off voltage in Li-ion batteries

Conventional view is that increasing the charging cut-off voltage will reduce the cycle life of LiNi0.8Co0.1Mn0.1O2 (NCM811) due to the intensification of electrode-electrolyte interface reaction, which strongly depends on the interface chemistry. However, we found the different trend when NCM811 is cycled in TLE electrolyte (ternary fluorinated lithium salts electrolyte). Specifically, the higher charging cut-off voltage applied, the better cycling stability obtained with 1000 cycles at 4.5 V/4.7 V, while 500 cycles at 4.3 V (capacity retention > 80 %). Herein, we revisit the correlation between cycling stability and charging cut-off voltage and have found that the cycling stability of NCM811 is more strongly related to interface chemistry. Charging at 4.5/4.7 V in TLE electrolyte, the content of inorganic components in cathode-electrolyte-interphase (CEI) and anode-electrolyte-interphase (AEI) are much higher than that obtained at 4.3 V due to the energy levels of the frontier molecular orbital of lithium salts, which is more resistant to oxidation and has higher mechanical strength to suppress the particle cracks. More importantly, the inorganic rich interface can prevent the crossover reaction between cathode and anode. This work clarifies the significance of interface chemistry to achieve high-voltage stability, and provides a valuable electrolyte formula for commercial application of high-performance Ni-rich layered oxide cathode at high-voltage.

Agronomic and environmental performance of bottom ash discharged from biomass-based thermal power plant

This study aimed to determine the applicability of bottom ash (BA) discharged from a biomass-based thermal power plant as an agricultural soil conditioner. The physicochemical and structural properties of BA used in this study were similar to those of wood-pellet-based biochar derived at 600 °C. Additionally, XPS, FTIR, and SEM-EDS described the structural properties of BA well proving that BA has a stable carbon structure. It was confirmed that BA has beneficial agricultural functions, such as improved soil physical properties, water holding capacity and nutrient residence time, and CO2 reduction. Toxicity tests were performed on five crops to evaluate the stability of BA; these results were similar to those of the control, without significant differences. The optimal BA treatment for Chinese cabbage cultivation was 100 kg/10a, which showed a yield index of 138 compared to that of the control. There was no significant difference in the physicochemical properties of the soil and the content of inorganic components in Chinese cabbage in the presence or absence of BA treatment. Overall, it is suggested that BA can be used as an effective soil-improving agent for the cultivation of crops in agricultural land as it has an excellent role in soil improvement and crop yield enhancement.

Effect of crown ether additive on the compatibility of electrolyte and hard carbon anode in sodium ion battery

The addition of additives is an ideal method to form solid electrolyte interface (SEI) and improve electrolyte solvation structure of Sodium-ion batteries. 15-Crown-5 is effective in improving the ionic solvation structure owing to its high coordination ability with Na+. Through physical characterization, it was analyzed that the crown ether molecules reaching the surface of hard carbon anodes driven by the electric field force could reduce the side reaction products of the hard carbon anode surface, lower the degree of polarization of the hard carbon anode, participate in the formation of uniform and smooth SEI films, augment the content of inorganic components in the SEI, and thus improve the sodium conductivity of the SEI. The addition of 15-Crown-5 proved to improve the compatibility between electrolyte and the hard carbon anode 15-Crown-5 and the hard carbon demonstrated excellent cycling performance of 300 cycles on the basis of the electrolyte, achieving a capacity retention of 95.69 % and an 8.87 % higher discharge specific capacity at 50 mA g−1as compared to the cell without the additive.

Catalytically Induced Robust Inorganic‐Rich Cathode Electrolyte Interphase for 4.5 V Li||NCM622 Batteries

AbstractTailoring inorganic components of cathode electrolyte interphase (CEI) and solid electrolyte interphase (SEI) is critical to improving the cycling performance of lithium metal batteries. However, it is challenging due to complicated electrolyte reactions on cathode/anode surfaces. Herein, the species and inorganic component content of the CEI/SEI is enriched with an objectively gradient distribution through employing pentafluorophenyl 4‐nitrobenzenesulfonate (PFBNBS) as electrolyte additive guided by engineering bond order with functional groups. In addition, a catalytic effect of LiNi0.6Mn0.2Co0.2O2 (NCM622) cathode is proposed on the decomposition of PFBNBS. PFBNBS with lower highest occupied molecular orbital can be preferentially oxidized on the NCM622 surface with the help of the catalytic effect to induce an inorganic‐rich CEI for superior electrochemical performance at high voltage. Moreover, PFBNBS can be reduced on the Li surface due to its lower lowest unoccupied molecular orbital , increasing inorganic moieties in SEI for inhibiting Li dendrite generation. Thus, 4.5 V Li||NCM622 batteries with such electrolyte can retain 70.4% of initial capacity after 500 cycles at 0.2 C, which is attributed to the protective effect of the excellent CEI on NCM622 and the inhibitory effect of its derived CEI/SEI on continuous electrolyte decomposition.

In English

The main idea of this work is to study the possibility of obtaining microcrystalline cellulose from multi-ton and low-value agricultural waste and investigation its structural properties. Air-dry soybean straw, an agricultural waste, was used for the research. Microcrystalline cellulose (MCC) was obtained from it by the method of organo-solvent cooking. Using the methods of XRD, XRF, FTIR-ATR, AFM, TGA and DSC, the structure and morphology of MCC were studied. It is found that increasing the hydromodule reduces the content of lignin and inorganic components. At the same time, both the yields of the MCC and its qualitative characteristics are declining. First of all, the crystallinity index of the MCC decreases with the increasing amount of the liquor ration. The band corresponded to symmetric CH2 bendings at 1435–1429 cm–1, that is known as the crystallinity band, decreased with increasing amount of the liquor ration. The AFM method shows that when forming the surfaces of MCC 10 particles, not only groups of particles are formed, the heights of the elements of which range from 23.8–28.1 to 16.9–26.8 nm, but also elongated units on the surface of which there are individual particles. The surface roughness is 1.6 nm. At the same time, the surface of the MCC 15 has a surface roughness Ra = 3.1 nm. The particles are distributed throughout the scan, with no clusters of particles and their agglomerates, and their heights are 14.4; 18.7; 20.6; 17.4 and 23.9; 18.1; 24.7 nm. 3D image of the particles showed that the particles are pyramids of different configurations similar to the particles in the MCC 10. It should be noted that the range of depressions and heights characteristic of MCC 15 is much smaller (from –13 to +20.7 nm) than in the MCC 10 (from –17.5 to 45.5 nm).

Effects of straw mulching and phosphorus application on forms and availability of soil phosphorus in hilly dryland of Sichuan, China

We conducted a two-factor split-plot experiment to examine the alteration of soil inorganic phosphorus forms and phosphorus availability under straw mulching and phosphorus fertilizer rates. The main factor was straw mulching and non-mulching, while the sub-factor was phosphorus supply rates, including 0, 75, and 120 kg·hm-2. We analyzed the characteristics of phosphorus adsorption-desorption, the content of inorganic phosphorus components and their relationship with available phosphorus in hilly upland purple soil in Sichuan. Results showed that compared with the non-mulching, the maximum phosphorus adsorption capacity of straw mulching was notably decreased by 7.7% and 7.4% in the two experimental years from 2018 to 2020. The degree of phosphorus saturation and readily desorbable phosphorus of straw mulching were remarkably increased by 35.4% and 21.6% in 2019 and 18.6% and 35.2% in 2020, respectively. The maximum buffer capacity of phosphorus was not different between straw mulching and non-mulching. The maximum phosphorus adsorption capacity and maximum buffer capacity of phosphorus were significantly lower, and the degree of phosphorus saturation was notably higher in the phosphorus application treatment than that under no phosphorus treatment. The readily desorbable phosphorus increased with the increases of phosphorus rates. The contents of dicalcium phosphate (Ca2-P), octa-calcium phosphate (Ca8-P) and iron phosphorus (Fe-P) in straw mulching treatment were notably higher than those in non-mulching treatment, whereas the content of aluminum phosphorus (Al-P) significantly lower under the straw mulching. Meanwhile, the contents of occluded phosphate (O-P) and apatite (Ca10-P) tended to decrease in the straw mulching compared with that under the non-mulching. Phosphorus application increased the content of different inorganic phosphorus components. Compared with the non-mulching, soil available phosphorus content and the phosphorus activation coefficient of straw mulching remarkably increased by 23.2% and 21.3% in 2019, and 9.6% and 8.9% in 2020, respectively. Soil available phosphorus content and phosphorus activation coefficient increased with the increases of phosphorus rate. Results of regression analysis showed that the contribution of inorganic phosphorus components to the availability of available phosphorus in purple soil was Ca2-P > Fe-P > Al-P > Ca8-P > Ca10-P > O-P. Therefore, straw mulching combined with a reasonable phosphorus fertilizer rate could promote the decomposition and transformation of insoluble soil phosphorus to moderately active or easily absorbed phosphorus forms, reduce soil phosphorus adsorption, stimulate soil phosphorus desorption, and improve soil phosphorus availability. Based on the economic benefits, phosphate fertilizer application at the rate of 75 kg·hm-2 combined with straw mulching was recommended in Sichuan hilly dryland, which would be more beneficial in improving soil phosphorus availability.

Effect of Soil Moisture and Calcium Deficiency on Incidence of New Branch Necrosis and Tip-Burn in Jujube (Zizyphus jujuba Mill.)

Jujube (Ziziphus jujuba Mill.) is the most important native species of Rhamnaceae, a large cosmopolitan family, and is one of the oldest cultivated fruit trees in the world. In recent years, consumption of fresh fruit and big fruit jujube has increased. The purpose of this study was to investigate the causes and its alleviation techniques of new branch necrosis and tip-burn, which occur in jujube during the new branch growth period. As a result of analyzing the inorganic component content of leaves, the calcium content was markedly 1.48% of abnormal samples compared to 1.90% of normal samples appeared low. Also, the calcium content in a necrotic new branch was also 0.14%, which was very low compared to 0.76% in the normal sample. In addition, the incidence rate of tip-burn at -30 kPa by soil at starting point of irrigation was 16.53%, higher than 7.22% at -10 kPa. The incidence of tip-burn by calcium foliar application was 0.6%, which was very low compared to control of 4.3%. Therefore, this study suggests that the symptoms of necrosis of new branch and tip-burn that occur during the new branch growth period of Jujube are related to the calcium content in the plant and lack of soil moisture and that calcium foliar application is effective in alleviating the occurrence of these abnormal symptoms.Alleviation effect of leaf tip-burn by Ca foliar application.

Sapropel – Mining Characteristics and Potential Use in Medicine

Abstract Found in lakes, freshwater sapropel is a sediment with a fine structure containing more than 10% of organic matter as well as residues of aquatic organisms with a small content of inorganic components of biogenic origin and mixture of mineral ingredients. The mud was first used in medicine by ancient Greeks, and it gained more popularity together with development of balneology in Europe in the 19th century as a remedy for several diseases. The last century also brought wider popularity in its cosmetic use. Despite its wide usage, mechanisms behind its effects are not so clear yet. Broad but fragmented studies on the effects of sapropel are available, but few have used modern research methods. There is evidence suggesting that its positive health effects are linked to its thermal capacity, ability of penetration in tissues and biological activity of its components, e.g., humic substances. Evidence also suggests antimicrobial activity and positive effects on skin regeneration. This review aims at summarising available knowledge on the structure and composition of sapropel and its effects on the human body, as well as its potential for further evidence-based use in medicine and cosmetics.

Proton-conducting Organic-inorganic Sulfo-containing Membranes for Fuel Cell

Cross-linked organiс-inorganic sulfo-containing membranes of various compositions based on acrylic monomers (acrylonitrile, acrylic acid, 3-sulfopropylacrylate potassium salt, ethylene glycol diacrylate) and sol-gel systems of tetraethoxysilane have been developed. Synthesis of the polymer matrix was carried out by UV-initiated polymerization of the monomer mixture and the inorganic component was formed in situ while conducting the sol-gel process of the precursor. FTIR, SEM, EDS, DMA, impedance spectroscopy were used to characterize the synthesized materials. The influence of inorganic component content on the properties of the membranes was investigated. DMA results show that an increase in silica content leads to a decrease in packing density and an increase in structural heterogeneity in sulfo-containing polyacrylate/silica membranes. The highest values of proton conductivity 1.12 ꞏ 10−2 Sm/cm at 60 °C were found in membranes containing 3 wt.%. of the added sol-gel system. Further increase of silica content does not increase the proton conductivity of the membranes. The proton transfer activation energies in the membranes were calculated from the temperature dependence of proton conductivity. The obtained cross-linked sulfo-containing organic-inorganic materials can be used for the development of proton-conducting membranes for fuel cells.

PHYSICAL AGING OF ORGANO-INORGANIC NANOCOMPOSITES BASED ON POLYIMIDE WITH CARD SUBSTITUENTS

The physical aging was investigated of obtained by sol-gel technology nanocomposites based on polyimide (PI) with card substituents and tetraethoxysylane (TEOS). The results for organic-inorganic composites, that contain of 5%. 20% or 50 % of TEOS, demonstrate that at temperatures well below (400K) the glass transition temperature of the polymer can take place changes in the dynamic characteristics of polymer macrochains and its permeability to low molecular probe as well as changes in aggregation of inorganic component. According to the methods of EPR, optical microscopy, etc. changes that occur in the characteristics of sol-gel polyimide based nanocomposites during long-term storage at temperatures much lower than the glass transition temperature of the polymer can be described as follows. The segmental mobility of the organic component is significantly reduced and the dynamic heterogeneity of the polymer increases. The decrease in the relative permeability of aged nanocomposites with increased content of inorganic component as compared with aged pure PI does not correlate with the content of TEOS in contrast to the initial samples of the same composition. PI macrochains chemically bonded to the inorganic phase have limited ability to realize an optimal conformation in the process of thermal relaxation (physical aging) so the increasing the content of the inorganic component has less effect on reducing the permeability of aged composites compared to aged pure PI. This is consistent with changes in the distribution of inorganic aggregates of composites. There are changes in the mean size of aggregates of inorganic particles in the composite and a decrease in their number. Smoothing is observed of the surface of nanocomposite films as well as disappearance of inhomogeneities caused by the surface of support. Due to the chemical bonding of inorganic particles and polyimide matrix, the peculiarities of the physical aging process of such composites are due to the mutual influence of the inorganic and polymer components.

Application of the method of thermal analysis to study the composition of chernozem in the European part of Russian Federation

The method of thermal analysis has been used to evaluate the content of inorganic and organic components in the Haplic Chernozems Pachic in the European part of the Russia. The study of the composition of the relevant soil samples was carried out at a temperature range of 20–1,000 °C, with heating rate of 5–20 degrees per minute. Thermal analysis makes it possible to assess the composition, thermodynamic and kinetic characteristics of the soils being analyzed and to compare the experimental data for improvement or development of various agricultural practices. We have developed a program for processing thermograms based on the MathLab package. Currently, there is an active anthropogenic intervention into soil-forming processes, which leads to a change in the qualitative composition of soil organic matter and humic substances. Derivatographic methods of analysis based on thermal destruction of the test sample, determination of the macrocomponent composition of the soil, release of the central and peripheral zones of humic substances according to their ability to be destructed in low and high temperature regions are informative in this field of research. The ratio of the fractions of these parts can serve as the most important indicator for the stability of the structure of soil organic matter.

Взаємозв’язки порушень біохімічного й імунологічного гомеостазу у хворих на ювенільний ревматоїдний артрит з урахуванням тривалості захворювання

Актуальність. Ювенільний ревматоїдний артрит (ЮРА) належить до довічних патологічних станів. Тому актуальними є дослідження, що вивчають закономірності його розвитку, функціонування метаболічних систем, розвиток дистрофічних змін на тлі запального процесу. Мета. Вивчення особливостей метаболізму сполучнотканинних структур відповідно до стану імунного гомеостазу на етапах еволюції ЮРА у хворих дитячого віку. Матеріали та методи. Вивчено особливості структурного складу компонентів сполучної тканини, вмісту мікроелементів, імунологічного гомеостазу у дітей із ЮРА. Проаналізовано 355 клінічних спостережень хворих на ЮРА з урахуванням ретро- і проспективних досліджень за 2012–2016 роки. Клінічна група становила 117 хворих на суглобову форму віком від 2 до 18 років (у середньому 6,0 ± 0,5 року). Результати. Дослідження імунного статусу визначило зниження рівня Т-загальних лімфоцитів (р < 0,001), Т-лімфоцитів-хелперів (р < 0,001), Т-супресорів/цитотоксичних (р < 0,001), підвищення імунорегуляторного індексу (р < 0,05), зменшення бактерицидної активності нейтрофілів (р < 0,001), збільшення показників тесту з нітросинім тетразолієм і зниження показника індексу стимуляції нейтрофілів (р < 0,001), підвищення рівня циркулюючих імунних комплексів (р < 0,001). Аналіз умісту прозапальних цитокінів довів підвищення рівня інтерлейкіну-1 (р < 0,05) та інтерлейкіну-6. Визначено залежність імунологічних показників від тривалості хвороби. Встановлено підвищення вмісту хондроїтин-4- та -6-сульфатів, кератан- і дерматансульфатів крові. Найбільші відхилення відзначались на перших етапах розвитку хвороби, що, безперечно, пов’язано з активністю патологічного процесу до призначення протизапального лікування або на перших етапах його отримання. У віддалені періоди захворювання відбувається зменшення рівня загальних глікозаміногліканів, хондроїтин-4- та -6-сульфатів, сповільнення екскреції уронових кислот (рt < 0,05). Аналіз змін у вмісті неорганічних компонентів залежно від тривалості хвороби виявив незначне зниження втрати організмом фосфору у період 3–5 років ЮРА. Аналіз відхилень імунобіохімічних співвідношень на різних етапах еволюції патологічного процесу виявив зміни кількості та характеру взаємозв’язків між показниками сполучнотканинного метаболізму й імунологічного гомеостазу. Висновки. Висока активність захворювання є основним предиктором розвитку дистрофічних змін, що підтверджується численними кореляційними взаємозв’язками показників обміну сполучної тканини та імунологічних параметрів. Найбільш несприятливими періодами є перші 1,5 року і через 3–5 років від початку захворювання. Виявлені зміни є підставою для проведення медикаментозної корекції біохімічного складу сполучнотканинних структур з метою профілактики розвитку вторинних дистрофічних змін в уражених суглобах у дітей з ЮРА, а також можуть відображати недостатню ефективність проведеного лікування та збереження субклінічної активності запалення.

Development and testing of a multi-element ICP standard

Determination of the calibration dependence of spectrometers’ output signal on the content of the measured elements is of great importance for the metrological assurance of the high-precision inductively coupled plasma (ICP) massspectrometry and optical emission spectrometry methods. This paper presents the results of a study on establishing the certified values of reference material of composition of multi-element solution of metals intended for inductively coupled plasma methods (ICP-CRM solution Multi 1). The reference material (RM) is a solution with certified values of the mass fraction of metals: barium, cadmium, cobalt, lithium, lead, and zinc. The solution was packed in high-density polyethylene bottles with the capacity of 4, 8, 15, 30, 60 and 125 cm 3 . The certified value of the mass fraction of metals in the solution was established by the calculation and experimental procedure and confirmed by the GET 217-2018 State Primary Standard of Unit of Mass Fraction and Unit of Mass (Molar) Concentration of Inorganic Components in Aqueous Solutions Based on Gravimetric and Spectral Methods. The permissible certified values of the mass fraction of metals in the developed ICP-CRM are shown to range from 900 mg/kg to 1100 mg/kg. The authors have embarked on the study of the reference material by testing RMs for long-term stability and determination of the RMs’ expiration date. It is assumed that the expanded uncertainty of measurements of the certified value of the mass fraction of metals in the solution of the multi-element ICP-CRM solution Multi 1 will not exceed 0.5 %. The ICP-CRM solution Multi 1 can be used for ensuring the metrological traceability of measurements in inorganic analysis using ICP-MS and ICP-OES to the GET 217-2018. The developed solution will also allow one of the main advantages of these methods to be applied in routine analysis, namely the ability to quickly and simultaneously measure several elements in samples.

Toward a mechanically stable solid electrolyte interphase

Toward a mechanically stable solid electrolyte interphase