Various Forms Of Iron Research Articles

Transcriptome deciphered the mechanisms of iron facilitating enzyme-mediated ciprofloxacin biodegradation and regulating antibiotic resistance gene dissemination through inducing genes expression

Refractory chemically synthesized quinolones are frequently detected in aquatic environments, and their degradation via biological systems presents substantial challenges, which includes obstacles in undergoing biological transformation, residual toxicity, the enrichment and dissemination of antibiotic resistance genes (ARGs) induced by quinolones. Various forms of iron, including zero-valent iron (ZVI), Fe (II), and Fe (III), were employed to enhance the biodegradation of quinolones and associated environmental risks control in toxicity-tolerated hydrolysis acidification (HA) system in this research. Iron addition significantly improves ciprofloxacin (CIP) removal (22.8% to 41.28% increase) through improving activity of enzymes, especially for the identified dehydrogenases via meta-transcriptomic sequencing. Regarding the risks associated with ARGs and their dissemination, ZVI and Fe(Ⅱ) exhibit positive effects, while Fe(Ⅲ) has an inverse effect. The minimized residual CIP contributes to the reduction of reactive oxygen species (ROS) responsiveness and cellular membrane permeability, thereby decreasing the risks of ARGs dissemination in iron-added systems. However, the enrichment of Fe(Ⅲ) reduction bacteria in Fe(Ⅲ)-added HA systems was speculated to led to increased ARGs dissemination by generating additional ROS and causing cell damage during the Fe(Ⅲ) biological reduction process. Changes in relevant gene expression for ARG conjunction, ROS generation, cell membrane permeability, and DNA repair, as observed through qPCR and meta-transcriptomic sequencing, support these conclusions. The findings suggest that ZVI and Fe(Ⅱ) contribute to reducing risks associated with ARGs and their dissemination in the biological system, which could be prioritized. This research also contributes insights into efficient quinolone removal and environmental risk migrating simultaneously through iron-enhanced biodegradation processes.

The role of intrinsic soil properties in the compressive strength and volume change behavior of unstabilized earth mortars

Despite the growing interest in earthen construction, there is critical lack of reliable experimental data on the soil properties which mostly affect the engineering characteristics of the dried building material. Therefore, the main objective of this research was to explore the influence of some of these properties, namely clay fraction content, Specific Surface Area (SSA), Cation Exchange Capacity (CEC), chemical and mineralogical composition and various forms of iron and calcium carbonate on earth mortars. The initial trigger for this research was the extraordinary compressive strength of four earth mortars prepared with different soils. So, these four soils, along with seven others from previous research, were thoroughly examined using soil science techniques to investigate the link between soil properties and compressive strength and linear shrinkage of earth mortars. A relationship between the compressive strength to CEC ratio and dry density was found, highlighting the decisive role of clay activity as expressed by CEC, in earthen materials properties. According to linear regression and dominance analysis, the strongest correlation was exhibited by SSA followed by CEC, demonstrating that compressive strength is largely dependent on these two properties. Less strong correlation was found for clay fraction content, while poorly ordered/amorphous iron oxides were found to correlate with strength and shrinkage, but their contribution requires further research. Regarding the mineralogical properties, it was found that the mortars that achieved the highest strengths contained poorly crystalline smectite clays. Finally, even significant differences in soil chemical composition did not necessarily lead to different mortar properties.

Новые подходы в лечении и профилактике анемии беременных

Iron deficiency anemia is the most common extragenital pathology in pregnancy. Its relevance is determined by its impact on obstetric and perinatal outcomes, since iron deficiency negatively affects the course of pregnancy and fetal development. Timely detection, treatment, and prevention of iron deficiency conditions during pregnancy are necessary to reduce the risk of complications. The article discusses the main issues and criteria of rational diagnosis and modern approaches to the anemia treatment. It notes the importance of timely and full correction of iron deficiency to avoid the development of fetal neurocognitive disorders. Special attention is paid to the choice of iron products, the benefits and drawbacks of various forms of iron that limit their use in pregnant women. Separately, an innovative dosage form sucrosomal® iron is viewed, which can be considered as an effective means of treating this pathology. The article also presents the clinical studies and pharmacokinetic characteristics of oral sucrosomal iron, using which the necessary effect is achieved with lower doses in the absence of adverse events, which is of paramount importance during gestation. KEYWORDS: anemia of pregnancy, iron deficiency anemia, iron deficiency, iron preparations, sucrosomal iron, sucrosome. FOR CITATION: Dobrokhotova Yu.E., Romanovskaya V.V., Narimanova M.R. New methods for the treatment and prevention of anemia during pregnancy. Russian Journal of Woman and Child Health. 2024;7(1):26–34 (in Russ.). DOI: 10.32364/2618-8430-2024-7-1-4.

Gallionellaceae pangenomic analysis reveals insight into phylogeny, metabolic flexibility, and iron oxidation mechanisms.

Neutrophilic iron-oxidizing bacteria (FeOB) produce copious iron (oxyhydr)oxides that can profoundly influence biogeochemical cycles, notably the fate of carbon and many metals. To fully understand environmental microbial iron oxidation, we need a thorough accounting of iron oxidation mechanisms. In this study, we show the Gallionellaceae FeOB genomes encode both characterized iron oxidases as well as uncharacterized multiheme cytochromes (MHCs). MHCs are predicted to transfer electrons from extracellular substrates and likely confer metabolic capabilities that help Gallionellaceae occupy a range of different iron- and mineral-rich niches. Gallionellaceae appear to specialize in iron oxidation, so it would be advantageous for them to have multiple mechanisms to oxidize various forms of iron, given the many iron minerals on Earth, as well as the physiological and kinetic challenges faced by FeOB. The multiple iron/mineral oxidation mechanisms may help drive the widespread ecological success of Gallionellaceae.

Facet-dependent U(VI) removal of hematite with confined ferrous ions.

The presence of ferrous minerals has been demonstrated to have a significant impact on the destiny, migration, and availability of uranyl (U(VI)) in natural surroundings. The iron oxide/Fe(II) system is a multifaceted iron reduction system anchored to surfaces, encompassing various forms of iron and ferrous ions. Several studies have investigated the effectiveness of adsorbed ferrous iron on iron-based minerals to facilitate the reduction of heavy metal ions and radioactive nuclides. A range of techniques for characterization, including X-ray photoelectron spectroscopy (XPS) and Mössbauer spectroscopy, were employed to explore the process of U(VI) adsorption and deposition, focusing on the limited region containing ferrous iron on the exposed crystalline surface of hematite. In this specific investigation, two kinds of hematite nanocrystals primarily exposing {001} and {012} crystal facets, referred to as HNPs and HNCs, were synthesized. Their ability to remove U(VI) was examined. Ferrous ions (Fe(II)) adsorbed onto the surface of hematite nanocrystals significantly enhanced the efficiency of U(VI) remediation. Furthermore, the HNCs/Fe(II) system showed better U(VI) reduction ability than the HNPs/Fe(II) system. Remarkably, HNCs produced and consumed more electrons and hydroxyl radicals, indicating a more intense response. This finding serves to highlight the significance of their role in interfacial effects and in predicting the spatial distribution of U(VI) in aqueous systems.

Поведение миграционных форм никеля в воде по континууму «эстуарий реки Миус – Таганрогский залив Азовского моря»

The studys results of nickel (Ni) migration forms in water along the continuum “the Mius River estuary - the Taganrog Bay of the Azov Sea” are presented. Standard methods, specialized equipment and mathematical and statistical analysis were applied. It is revealed that experimental data on the content of the nickel dissolved form do not exceed global background concentrations. The nickel suspended migration form with dominant values in the Mius River zone (54-71 % of the gross content) prevailed along the continuum. A symbiotic behavior was established for all Ni migration forms with a general decrease in concentrations along the profile of “the Mius River→the Taganrog Bay”. A correlation analysis was carried out between the contents of Nigr., Nidis., Nisusp., Nisusp. in % of the total and physical and chemical parameters, as well as various forms of iron. The significance level of p≥0.05 was noted in the pair S (‰) and Nigr., Nidis., Nisusp., and moderate direct connections are characteristic of the pairs Ni susp. in % of the total – Fegr., Nigr. – Fesusp. in % of Fegr. and Nisusp. in % of the total – Fesusp. in % of Fegr.. With a sub-parallel decrease in these indicators, the withdrawal of both nickel and iron into the bottom sediments was recorded.

Direct modulation of hepatocyte hepcidin signaling by iron.

BACKGROUNDLiver-secreted hepcidin is the systemic master switch of iron homeostasis and decreased levels of hepcidin are considered to cause iron overload not only in hereditary hemochromatosis but also in hemolytic anemia and chronic liver diseases. The regulation of hepcidin is complex and its response to iron is still not completely understood. AIMTo study the direct effect of iron on various established hepcidin signaling pathways in hepatoma cells or primary hepatocytes. METHODSHepcidin mRNA expression was studied by quantitative real-time (qRT)-PCR in the presence of various forms of iron including ferric ammonium citrate (FAC) in hepatoma cells (Huh7), murine primary hepatocytes and an established co-culture model of phorbol myristate acetate-differentiated THP-1 monocytes and Huh7 cells. To analyze hepcidin signaling, the response to bone morphogenetic protein 6 (BMP6), interleukin (IL)-6, IL-1β, hypoxia and lipopolysaccharide (LPS) were studied. Hepcidin and small mothers against decapentaplegic 6 (SMAD6) mRNA levels were assessed by qRT-PCR and the expression of phosphorylated signal transducer and activator of transcription 3 (phospho-STAT3), STAT3, phospho-SMAD1/5/8 and SMAD1 proteins were analyzed by western blot.RESULTSAll iron III forms including FAC efficiently blocked hepcidin mRNA expression at non-toxic dosages in Huh7 cells or primary hepatocytes in a time and dose-dependent manner (P < 0.001; P < 0.05). Hepcidin blockage could be efficiently blunted by iron chelators salicylaldehyde isonicotinoyl hydrazone (SIH) and Desferal (P < 0.001). FAC also inhibited BMP6, hypoxia, IL-1β and IL-6-mediated hepcidin induction (P < 0.001; P < 0.001; P < 0.05; P < 0.001), and FAC also inhibited LPS-mediated hepatic hepcidin induction in co-culture model (P < 0.001). Moreover, FAC reduced SMAD6 mRNA and p-SMAD1/5/8 protein expression at basal or upon stimulation by BMP6 (P < 0.05; P < 0.01), and FAC also reduced SMAD6 and p-SMAD1/5/8 expression under hypoxia (P < 0.01; P < 0.05). However, FAC has no significant effect on p-STAT3 protein expression at basal or upon stimulation by various stimuli. Notably, in the presence of the BMP/SMAD signaling pathway inhibitor LDN193189 Hydrochloride (LDN), FAC was unable to further decrease hepcidin, SMAD6 and p-SMAD1/5/8 expression compared with LDN alone. CONCLUSIONIron directly blocks hepatocellular hepcidin signaling through the BMP/SMAD pathway but independent of STAT3. This mechanism may contribute to continued iron overload in many pathophysiological conditions ultimately causing a vicious cycle of continued hepcidin suppression.

Формы железа в почвах естественных ландшафтов Верхнего Приангарья

Iron occupies one of the leading places among other elements in terms of content in soils and, having the ability to change valence and properties, diagnoses the typical and sub-type features of many soils, and most importantly, the direction of the soil formation process. Gypsum-bearing soils are formed on the deluvium of the Cambrian sedimentary rocks, in conditions of a hilly-flat relief, caused by water-erosion processes that have created surface dissections by numerous valleys and hollows. Gypsum-bearing soils are located on the elevated parts of the relief of the first floodplain river terraces, as well as in the lower parts of the relief and in river valleys. The climatic conditions of soil formation can be classified as arid. The amount of precipitation in the study area is much less than evaporation. The content, composition, and ratios of various forms of iron and the profile distribution of soils formed on gypsum-bearing red-colored Cambrian sedimentary rocks of the Upper Angara region were studied. For this, the composition of the soil cover in the landscape under study and the soilforming processes taking place in the soils were determined: brown arid calcareous soils are formed in the southern exposure of the slopes; in the northern exposure - chernozems, chernozems and meadow soils. An important morphoanalytical feature of soils is the presence of significant amounts of gypsum and carbonates in the profile. The leading soil-forming process in the landscape is the process of humus accumulation, which is clearly manifested in soils on the slopes of the left bank of the Zalari River. The group composition of iron was determined by analytical methods. The ratios of various iron groups, which are characteristic of landscape soils, and the regularities of the distribution of groups in soil profiles have been established. It was revealed that the degree of ferruginization of the soils of the left bank is in moderately low and very low limits; the degree of ferruginization of soils on the right bank is moderately low. The iron groups in the profiles are poorly differentiated. Silicate iron prevails over non-silicate. The significant predominance of silicate forms of iron over non-silicate forms indicates a low intensity and weak development of weathering processes. In all soils of the landscape, only traces of amorphous iron are determined. The mobility of iron in the soils of the landscape is practically absent, due to the insufficient amount of the amorphous form. In all landscape soils, the degree of oxidogenesis is very low. Crystallization of free iron oxides and hydroxides does not occur due to their absence.

HISTORY OF FORMATION OF PLAYING SPACES FOR CHILDREN IN CITIES

The relevance of research of the formation of children's play spaces is determined by the gradual transformation from small areas with sand near schools to the first attempts at a design approach to arranging such territories using iron structures and organizing a play environment for children of different ages and physical capabilities. Wartime had a negative impact on the development of gaming spaces, which resulted in the destruction of all iron equipment in the gaming spaces. However, there are positive sides, this period contributed to the development of children's imagination and the creation of adventure themes for games - plots, scenarios, quests began at this time. It is necessary to highlight the period after the war - "The era of novelty." When the playgrounds were traumatic and the equipment was poorly handled Much attention was paid to the safety of children in playgrounds and spaces. A huge step forward was the architectural and design influence, which manifested itself in the form of various forms of iron - rockets, ships, slides, creative tunnels and other figures that were placed in the play spaces. Americans were among the first to start creating entire theme parks (Oxland, California). A large number of artists built exhibits, frescoes, toys and sculptures in the park. The formation of a new architectural and design space on playgrounds has turned into the creation of whole theme parks and amusement parks. Special attention should also be paid to the transformation of children's playgrounds into family play spaces, where both parents and children were equally involved in the game process. This influenced the perception of children, their attitude towards parents and had a positive result in understanding the unity of the family. Each period of time XVIII-XX can be designated by different stages: social, economic, cultural and security stage. They were also due to political relationships between countries (war) and within countries. Thus, we can say that even unfavorable conditions in the country can have a positive effect on the development of children of different ages thanks to the play environment and adapted spaces for this pastime. Keywords: children's play spaces, playgrounds, children's games, history of play spaces, architectural design, formation.

Magneto-optical/ferromagnetic-material computation: Bäcklund transformations, bilinear forms and [formula omitted] solitons for a generalized (3+1)-dimensional variable-coefficient modified Kadomtsev–Petviashvili system

Of current interest, magneto-optics deals with the phenomena associated with magnetic effects on matter as it emits light, having the potential applications in computer data-storage and waveguides, while ferromagnetic materials are the ones displaying ferromagnetism, such as the various forms of iron, steel, cobalt, nickel, and their alloys. In this paper, in magneto-optics, ferromagnetism, fluid mechanics and plasma physics, we investigate a generalized (3+1)-dimensional variable-coefficient modified Kadomtsev–Petviashvili system for the electromagnetic waves in a ferromagnetic material, or water waves, or dust-acoustic/ion-acoustic/dust–ion-acoustic waves in a plasma. Special cases of the system in those fields are listed out, such as one special case in magneto-optics, which describes the electromagnetic waves in an isotropic charge-free ferromagnetic thin film with the potential application in magneto-optic recording. With symbolic computation, we work out (1) two sets of the variable-coefficient-dependent auto-Bäcklund transformations along with some solitonic features, (2) the variable-coefficient-dependent bilinear forms with the Hirota method and (3) two branches of the variable-coefficient-dependent N-soliton solutions with N being a positive integer. Relevant constraints on the variable coefficients are presented.

Assessment of elements mobility in anthropogenic layer of historical wastes related to glass production in Izera Mountains (SW Poland)

A geophysical survey conducted in the remote forest glade, located in the Izery Mountains (SW Poland), revealed the existence of an anthropogenic layer of historical glass wastes dumped in this area during the activity of a glass factory in the 18th and 19th centuries and domestic wastes dumped during the second part of the 20th century. The aim of the study was assessment of potential ecological risk related to the release of potentially toxic elements to the soil, groundwater and surface waters. The assessment was done on the base of classical geochemical analysis supported by calculation of environmental indices as well as on mobility of elements (leaching test and BCR sequential extraction). As an innovative aspect in the geostatistical interpretation of the data, some magnetic parameters (magnetic susceptibility-χ, χ/Fe ratio) were also used. It allowed for a better understanding of the relationship of PTEs with various forms of iron. The BCR sequential extraction found that among the PTEs, only Zn (up to 43%) was in a potentially mobile fraction probably occurring in ionic form, associated with iron oxides only by surface adsorption forces. The leaching has shown a slight increase in Zn and Cu content in the surface waters; however, it was not considered to be a real ecological threat because the pH of the waste material and soil cover is >6.0 and the scenario of a radical decrease in pH is rather unrealistic. The other PTEs were associated with more stable E2, E3 and E4 fractions. Zinc, similar to Ni, Co and Cu in waste samples, was highly correlated with magnetic parameters (χ and χ/Fe). It means that a considerable part of these metals was associated with ferrimagnetic iron oxides, although they can also occur in the form of inclusions in aluminosilicates and enclosed in glassy phases.

Pedogenic Forms of Iron in Soils Developed from Four Parent Materials

Information on the distribution of various forms of iron in soils are valuable in the study of soil genesis. The objective of this study was to to evaluate the pedogenic forms of iron in soils developed over basement complex and basaltic parent materials of the study area. Geologic units considered in the basement complex area were granite gneiss, biotite granite and migmatite. Stratified random sampling formed the basis for field work. Soil sampling was carried out by digging at least two soil profile pits in each geologic unit. Organically bound, amourphous and total iron oxides were estimated using 0.1 M sodium pyrophosphate, acidified (pH 3) ammonium oxalate, and dithionite-citrate-bicarbonate method, respectively. The total Fe in the soil samples were determined after a mixed acid digestion. In general, total iron fractions were statistically similar among the soils of basement complex geologic units but significantly lower than those of soils derived from basaltic rocks. However, the distribution of iron oxide fractions was similar among the basement and basaltic geologic units. Furthermore, there were significant differences in the distribution of iron oxides in the B horizons of basement complex derived soils. Consequently, the quantity of iron oxides in the B horizon was in the order migmatite &gt; biotite granite &gt; granite gneiss. About 70% of total iron oxides in the soils over granite gneiss, biotite granite and basaltic rocks was amorphous in nature. Furthermore, total iron oxides constitute less than 20% of total clay both in the basement complex and basaltic soils.

Influence of different forms of iron on the morphobiological indicators of Pinus sylvestris

The wide distribution of iron in the environment of various forms of iron makes it relevant to study the characteristics of their influence on plant growth. In the present paper, the growth features of Pinus sylvestris – Scots pine were studied - during the cultivation of stratified seeds in a medium containing different forms of iron. It was established that the cultivation of pine seeds in a medium containing 0.1 M of iron in any form, inhibits the development of the root system. When cultivated in the environment containing iron nanoparticles at a concentration of 6.25 mmol / l, this led to a decrease in the root length to 3.71 ± 0.06 mm. On the contrary, the presence of iron nanoparticles in the medium for the cultivation of pine caused an increase in the length of the main and adventitious roots, as well as the number of adventitious roots. The content of iron microparticles in the medium for the cultivation of pine caused only a decrease in the length of the main root and adventitious roots. At the same time, at concentrations from 0.39 to 25 mmol / l, an increase in the number of adventitious roots occurred, which indicates compensatory reactions.

Influense of various forms of iron on growth of Chlorella vulgaris Beijer culture

A comparative study of the toxic effect of magnetic nanoparticles of iron oxide (MNPs) and ions of bivalent and trivalent iron in the composition of sulfates on the growth of an intensive culture of Chlorella vulgaris Beijer is provided. The high sensitivity of the introduced biotest is shown for the case of a standard toxicant (potassium dichromate). Using the probit-analysis, and semi-extincting specific growth rate of EC50 culture concentrations were established in four-day experiments, which amounted to 1.3 ± 0.2 mg/l for potassium dichromate, 0.8 ± 0.1 mg/l for ferrous iron, 2.0 ± 0.2 mg/l for trivalent 1 and for MNPs iron oxide – 13 ± 1 mg / l. The probit analysis features and the significantly lower semi-suppressing specific growth rate of the culture in experiments with MNPs compared with ionic iron suggests a possible manifestation of other forms of exposure that are not related to the mechanism of chemical intoxication.

Geochemical Anomalies of Frozen Ground due to Hydrocarbon Migration in West Siberian Cryolithozone

According to the study of frozen deposits in the territory south of the Taz Peninsula, geochemical processes are considered under the hydrocarbon migration from the lower productive complex. An analysis of the cryolithological structure of the frozen stratum was performed, and the composition of the gas and authigenic associations was studied. It was shown that the migration of gases is caused by shear deformations with the formation of cryogenic textures with the presence of gas-bearing ice crystallites on slip surfaces. It was found that the migration of hydrocarbons causes significant local changes in pH/Eh parameters in the frozen stratum and determines the micromosaic distribution of sulfate and iron reduction processes that lead to the formation (including microbiological processes) of various forms of iron: sulphides, carbonates and oxides.

An insoluble iron complex coated cathode enhances direct electron uptake by Rhodopseudomonas palustris TIE-1

Microbial electrosynthesis (MES) is a promising bioelectrochemical approach to produce biochemicals. A previous study showed that Rhodopseudomonas palustris TIE-1 can directly use poised electrodes as electron donors for photoautotrophic growth at cathodic potentials that avoid electrolytic H2 production (photoelectroautotrophy). To make TIE-1 an effective biocatalyst for MES, we need to improve its electron uptake ability and growth under photoelectroautotrophic conditions. Because TIE-1 interacts with various forms of iron while using it as a source of electrons for photoautotrophy (photoferroautotrophy), we tested the ability of iron-based redox mediators to enhance direct electron uptake. Our data show that soluble iron cannot act as a redox mediator for electron uptake by TIE-1 from a cathode poised at +100mV vs. Standard Hydrogen electrode. We then tested whether an immobilized iron-based redox mediator Prussian blue (PB) can enhance electron uptake by TIE-1. Chronoamperometry indicates that cathodic current uptake by TIE-1 increased from 1.47±0.04 to 5.6±0.09μA/cm2 (3.8 times). Overall, our data show that immobilized PB can enhance direct electron uptake by TIE-1.

Bacterial cyclic β-(1,2)-glucans sequester iron to protect against iron-induced toxicity.

Cellular iron homeostasis is critical for survival and growth. Bacteria employ a variety of strategies to sequester iron from the environment and to store intracellular iron surplus that can be utilized in iron-restricted conditions while also limiting the potential for the production of iron-induced reactive oxygen species (ROS). Here, we report that membrane-derived oligosaccharide (mdo) glucan, an intrinsic component of Gram-negative bacteria, sequesters the ferrous form of iron. Iron-binding, uptake, and localization experiments indicated that both secreted and periplasmic β-(1,2)-glucans bind iron specifically and promote growth under iron-restricted conditions. Xanthomonas campestris and Escherichia coli mutants blocked in the production of β-(1,2)-glucan accumulate low amounts of intracellular iron under iron-restricted conditions, whereas they exhibit elevated ROS production and sensitivity under iron-replete conditions. Our results reveal a critical role of glucan in intracellular iron homeostasis conserved in Gram-negative bacteria.

Anaemia of chronic kidney disease: diagnosis, assessment and treatment

Many patients with chronic kidney disease also present with anaemia. In this article, Karen Jenkins provides an overview of anaemia of chronic kidney disease—its definition, the processes in the body that lead to it, and its signs and symptoms. Kidney care professionals will also find up-to-date information about the various forms of iron and erythropoietic therapies available.

Quantitative distribution of phytoliths as reliable diagnostical criteria of ancient arable lands

Abstract People ploughed the soils in the central part of Russia for at least two thousand years, based on historical documents and archaeological artifacts. However, we cannot find any traces of ancient arable land, because after a 200–250 year uncultivated period, all morphological and chemical properties have disappeared. Two soils near Moscow (Russia) were studied: buried and modern. The first soil was under an 800-year-old burial mound and the second one was nearby. It seemed that modern soil was also tilled in the past, but nothing in morphology and chemical properties indicated that. We used phytolith analysis to investigate if a typical arable distribution of phytoliths has been preserved in the soil after an 800 year uncultivated period. The ancient plough layer has been completely transformed within the past 700–800 years. Its smooth lower boundary has totally disappeared and its chemical characteristics have changed, including the reaction of soil solution, organic matter distribution, content and distribution of various forms of iron. It is possible to distinguish some stable indicators of ploughing, which have weakly changed even after a period of 700–800 years, and allow us to interpret the ancient land use. Such indicators include the distribution of bulk phosphorus. While the native soils show an accumulative trend with maximal concentration of total phosphorus within the sod horizon, the arable soils are characterized by a uniform level of total phosphorus throughout the plough layer and, in some cases, also enrichment in this element along the former plough line (lower boundary of plough horizon). The other relatively stable indicator is the clay distribution pattern. The eluvial–illuvial distribution pattern is preserved in both buried and modern soils. During the arable period of land use, a special pattern of phytolith distribution was formed within the upper part of the soil, with the maximum concentration of phytoliths along the plough line. This pattern has been preserved for hundreds of years with only a slightly smoothened shape. Therefore, the quantitative distribution of phytoliths within a soil profile is a stable indicator that can serve as a reliable diagnostic feature of ancient arable stages, even when all other diagnostic indicators are absent. The presence of phytoliths from cultivated cereal crops (dendritic form) within the upper layer is an additional confirmation of the former arable use of the soil.

Dynamics of iron content in the soils of technogenic landscapes of forest-steppe areas in the Kuznetsk basin

The study of iron content in young soils formed on pit heaps of technogenic landscapes allow us to diagnose the soil formation processes occurring there. Monitoring the content and distribution of various forms of iron in embriozems shows the speed and direction of the soil-forming processes in disturbed ecosystems. It is detected that the ratio of different forms of iron and their distribution in the soil profile can be used as an indicator.