Search Results (50)

Bacground/Objectives: Cervical intraepithelial neoplasia (CIN) comprises a range of precancerous cervical lesions, and timely detection and intervention are essential to avert the development to invasive cervical cancer. Our previous study showed specific elemental alterations in the serum of patients with diagnosed CIN. In this study, we aimed to determine the levels of trace elements (Be, Cr, Mn, Co, Ni, Cu, Zn, Se, Cd, Tl, Pb, Rb, Sr, Mo, Th, and U) in more valuable materials, cervical tissue samples collected from patients diagnosed with CIN 2 and 3 (n = 60). Methods: The control group consisted of healthy, pathologically unaltered samples from the same patients (n = 60). The concentrations of all trace elements were determined using inductively coupled plasma–mass spectrometry (ICP-MS). Key demographic and clinical data were statistically analyzed in the context of trace element levels in cervical tissues. Results: We discovered that CIN 2 and CIN 3 tissues had significantly higher concentrations of essential trace elements Cr, Co, Se, and Mo, and toxic trace elements Be, Ni, and Cd compared to controls. The findings of this study highlight the differences in trace element concentrations in CIN tissue samples compared to controls. Conclusions: The presented results suggest the possible role of trace elements in the pathophysiological processes that lead to neoplasms in cervical tissues. The results provide initial and pivotal insight into the trace element concentrations in CIN tissues, which could aid further studies regarding cervical neoplasms and their pathogenesis. Full article

Mold copper plates (Cr–Zr–Cu alloy) frequently fail due to severe wear under high-temperature conditions during continuous casting. To solve this problem, Inconel 718 coatings were prepared on the plate surface via laser cladding to enhance its high-temperature wear resistance. The results demonstrate that the coatings exhibit a defect-free structure with metallurgical bonding to the substrate. The coating primarily consists of a γ-(Fe, Ni, Cr) solid solution and carbides (M₂₃C₆ and M₆C). Notably, elongated columnar Laves phases and coarse Cr–Mo compounds were distributed along grain boundaries, significantly enhancing the coating’s microhardness and high-temperature stability. The coating exhibited an average microhardness of 491.7 HV_0.5, which is approximately 6.8 times higher than that of the copper plate. At 400 °C, the wear rate of the coating was 4.7 × 10⁻⁴ mm³·N⁻¹·min⁻¹, significantly lower than the substrate’s wear rate of 8.86 × 10⁻⁴ mm³·N⁻¹·min⁻¹, which represents only 53% of the substrate’s wear rate. The dominant wear mechanisms were adhesive wear, abrasive wear, and oxidative wear. The Inconel 718 coating demonstrates superior hardness and excellent high-temperature wear resistance, effectively improving both the surface properties and service life of mold copper plates. Full article

This study aimed to assess the pollution levels, sources, ecological risk, and human health risks of metal(loid)s in water, sediment, and muscle tissue of Prochilodus lineatus and Pimelodus maculatus from rivers in the state of Mato Grosso do Sul, Brazil. The metal(loid)s content in river sediment, water, and fish tissue were determined by inductively coupled plasma optical emission spectrometry. Sediment pollution assessment was carried out by geo-accumulation index, contamination factor, enrichment factor, and pollution load index. There were significant differences in concentration values for Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb, and Hg. There was greater tendency for the elements Cu, Ni, Cu, N, Co, As, Hg, Al, and Co in the waters of the Anhanduí River in 2020 and Cr and Pb in 2021. The concentrations of As, Cd, Co, Cr, and Hg in the waters of the Anhanduí River are above the permitted limit values for heavy metal ions in drinking water established by the WHO. The concentrations of heavy metals in the sediments of rivers are above the limit set by Conama/Brazil and other countries. The sediments were very highly contaminated by Cd and Mo, and with moderate contamination of Pb. All sediments of rivers showed a decline in site quality, which indicates that it is polluted. Sediments were classified with severe enrichment by Cd and Mo. The content of Al was the highest in P. lineatus and P. maculatus in relation to other elements analyzed. There was also the presence of elements such as Cr, Cu, Cd, Hg, Ni, As, Pb, Mo, and Co in the tissues of the fish species. Therefore, the contamination of these rivers is a concern due to human consumption of fish, since there is a carcinogenic risk related mainly to As and Cd. Full article

The circular economy practice of using waste to fertilize plants should be more widespread. It is a means to manage natural resources sustainably in agriculture. This approach is in line with organic and sustainable farming strategies, reducing the cultivation costs. Organic waste dumped into a landfill decomposes and emits greenhouse gases. This can be reduced through its application to energy crops, which not only has a positive impact on the environment but also improves the soil quality and increases yields. However, organic waste with increased content of heavy metals, when applied to the soil, can also pose a threat. Using Miscanthus × giganteus M 19 as a test plant, an experiment with a randomized block design was established in four replications in Central–Eastern Poland in 2018. Various combinations of organic waste (municipal sewage sludge and spent mushroom substrate) were applied, with each dose containing 170 kg N ha⁻¹. After three years (in 2020), the soil content of total nitrogen (N_t) and carbon (C_t) was determined by elemental analysis, with the total content of P, K, Ca, Mg, S, Na, Fe, Mn, Mo, Zn, Ni, Pb, Cr, Cd, and Cu determined by optical emission spectrometry, after wet mineralization with aqua regia. For the available forms of P and K, the Egner–Riehm method was used, and the Schachtschabel method was used for the available forms of Mg. The total content of bacteria, actinomycetes, and fungi was also measured. The application of municipal sewage sludge (SS) alone and together with spent mushroom substrate (SMS) improved the microbiological composition of the soil and increased the content of N_t and C_t and the available forms of P₂O₅ and Mg more than the application of SMS alone. SMS did not contaminate the soil with heavy metals. In the third year, their content was higher after SS than after SMS application, namely for Cd by 12.2%, Pb by 18.7%, Cr by 25.3%, Zn by 16.9%, and Ni by 14.7%. Full article

Huelva is a city in SW Spain with 150,000 inhabitants, located in the proximity of two heavy chemical industry complexes, the highest naturally occurring radioactive material (NORM) waste (phosphogypsum) stacks of Europe and a highly polluted estuary, with elevated cardiovascular disease and cancer mortality rates. This study analyses the association between cumulated exposure levels to 16 metal(loid)s (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Tl, U, V, and Zn) measured in the toenail of a sample (n = 55 participants) of the general control population of Huelva City who were involved in the MCC-Spain study and the spatial proximity patterns to the local polluting sources. Residents of the city of Huelva have higher levels of Fe, Ni, Cr, Se, As, and Co in their toenails compared to the levels found in populations with similar characteristics living in non-polluted areas. Moreover, the highest concentrations of As, Pb, Cd, Mo, and Se were found in toenails of participants living near the NORM waste stack, while the highest Cu, Zn, and Al contents corresponded to people residing near the industrial area. The spatial distribution of most of the metal(loid)s studied appears to be mainly controlled by anthropogenic factors. Full article

The main objective of this study was to compare the effectiveness of an innovative multi-nutrient fertiliser (PRO complete) applied foliarly with a standard fertiliser (TRA complete) in triticale crops. PRO complete contained macronutrients (N, P, K), micronutrients (B, Cu, Fe, Mn, Mo, Zn, with Fe and Zn complexed with amino acids), and trace elements (Cr, I, Li, Se—combined with plant extracts). TRA complete had the same quantitative composition, but the micronutrients and trace elements were in mineral form or in complex with EDTA. The experiment was conducted on triticale grown in a soil culture in a growing hall. The triticale yield and quality were determined. The fertilisers had no significant effect on straw yield and macronutrient (N, P, K, Mg, Ca) content in straw and grain. They caused a significant increase in grain yield, but PRO complete was more effective, also in terms of increasing the content of some micronutrients, particularly in straw. Both fertilisers increased the content of Cr, Li, and Se in straw. The application of the fertilisers contributed to some extent to triticale biofortification. In conclusion, the use of foliar multi-compound fertilisers is a beneficial choice for optimising crop yield and quality. However, their chemical composition and dosage should be further developed. Full article

Some trace elements are essential for the health of vertebrates, but little is known about their function, the amounts required, and the factors influencing their metabolism in tortoises. The aim of this study was therefore to measure trace elements (chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), selenium (Se), zinc (Zn)) in heparinized blood plasma of Hermann’s tortoises (Testudo hermanni) (n = 520) from March to September 2022 using inductively coupled plasma mass spectrometry (ICP-MS) and to establish specific reference intervals. Additionally, the influence of sex, season, and region of sample collection on the measured values were evaluated. Significant (p ≤ 0.05) sex-specific differences were found for Cu, Mg, and Mn; seasonal differences were found for Cr, Cu, Mn, Mo, and Se; and the region in which the tortoises were kept significantly impacted Cr, Cu, Fe, Mg, Mo, and Se levels. The results show that all of these factors should be consider when establishing and interpreting blood trace element levels in tortoises. Full article

Cu-based ternary oxides with delafossite structure have received considerable attention in recent years for their versatility in a wide range of applications, among which is the possibility to use them in heterostructure solar cells as hole transport layers, due to their promising behavior as p-type conducting oxides. Ab initio calculations have been performed with density functional theory to investigate the role of the trivalent metal within the CuMO₂ structure and the dependence of structural and electronic properties with the species (M = Al, Ga, In, Fe, Cr, Co, Sc, Y) occupying the site of the metal. Generalized Gradient Approximation also including a Hubbard term and nonlocal Heyd–Scuseria–Enzerhof screened hybrid functional schemes were tested and their results were compared. Excellent agreement with experimental lattice parameters and measured gaps have been found. The use of hybrid functionals in HSE approximation considerably improves the bandgaps when compared with the experimental results but takes considerable time to converge, hence the need to explore less demanding methodologies. Trends in the geometry as well as in the electronic properties are discussed, and the effect of mixing different metals (CuM_xN_1−xO₂, M, N being the aforementioned elements) in the geometry and electronic properties of these delafossite materials is investigated. Due to the high cost of HSE calculations, especially when supercells are needed to model several x concentrations, statistical models and techniques based on machine learning have also been explored to predict HSE bandgap values from GGA and structural information. Full article

Depending on operating conditions, metals and alloys are exposed to various factors: wear, friction, corrosion, and others. Plasma surface alloying of machine and tool parts is now an effective surface treatment process of commercial and strategic importance. The plasma surface alloying process involves adding the required elements (carbon, chromium, titanium, silicon, nickel, etc.) to the surface layer of the metal during the melting process. A thin layer of the compound is pre-applied to the substrate, then melted and intensively mixed under the influence of a plasma arc, and during the solidification process, a new surface layer with optimal mechanical properties is formed. Copper-based alloys—Cu-X, where X is Fe, Cr, V, Nb, Mo, Ta, and W—belong to an immiscible binary system with high mechanical strength, electrical conductivity, and magnetism (for Fe-Cu) and also high thermal characteristics. At the same time, copper-based alloys have low hardness. In this article, wear tests were carried out on coatings obtained by plasma alloying of CuSn10 and CrxCy under various friction conditions. The following were chosen as a modifying element: chromium carbide to increase hardness and iron to increase surface tension. It is noted that an increase in the chromium carbide content to 20% leads to the formation of a martensitic structure. As a result, the microhardness of the layer increased to 700 HV. The addition of CuSn10 + 20% CrxCy and an additional 5% iron to the composition of the coating improves the formation of the surface layer. Friction tests on fixed abrasive particles were carried out at various loads of 5, 10, and 50 N. According to the test results, the alloy layer of the Fe-Cr-C-Cu-Sn system has the greatest wear resistance under abrasive conditions and dry sliding friction conditions. Full article

The photosynthetic pigments, protein, macro and microelements concentrations, and fatty acids composition of Salvinia natans, a free-floating aquatic plant, were analyzed after exposure to Hoagland nutrient solution containing 1, 3, and 5 mg/L Li. The Li content of Salvinia natans grew exponentially with the Li concentration in the Hoagland nutrient solution. The exposure to Li did not induce significant changes in Na, Mg, K, Cu, and Zn content but enhanced the Ba, Cr, Mn, Ni and Mo absorption in Salvinia natans. The most abundant fatty acids determined in oils extracted from Salvinia natans were C16:0, C18:3(n6), C18:2(n6), and C18:3(n3). The photosynthetic pigments did not change significantly after exposure to Li. In contrast, chlorophyll and protein content decreased, whilst monounsaturated and polyunsaturated fatty acids content increased after the exposure to 1 mg/L Li. The results indicated that Salvinia natans exposed to low Li concentrations may be a good source of minerals, omega 6 and omega 3. Full article

Gums and carrageenans are food additives widely used in food preparations to improve texture and as viscosifiers. Although they are typically added in small amounts, nowadays people tend to use more and more pre-prepared food. In this work, the content of a wide panel of trace elements in commercial products were analyzed. Carrageenans and gums (n = 13) were purchased in the Portuguese market and were from European suppliers. Samples were solubilized by closed-vessel microwave-assisted acid digestion and analyzed by ICP-MS. Globally, the content of essential trace elements decreased in the following order: Fe (on average, on the order of several tens of µg/g) > Mn > Zn > Cr > Cu > Co > Se > Mo (typically < 0.1 µg/g), while the content of non-essential/toxic trace elements decreased in the following order: Al > Sr > Rb > As > Li > Cd > Pb > Hg. The consumption of these food additives can significantly contribute to the daily requirements of some essential trace elements, namely Cr and Mo. The toxic trace elements Cd, As, Pb, and Hg were below the EU regulatory limits in all analyzed samples. Additional research is needed to define the potential risk of introducing toxic trace elements into food products through the use of these additives. Full article

The exposure of plants to weak magnetic fields (MFs) of various intensities and for different times is increasingly adopted to sustainably enhance plant growth in plant-based applications such as modern agriculture, phytoremediation and biogas production. However, little is known about the effects of MF exposure on plant chemical composition, and in turn on related ecosystem processes, such as the transfer of potentially toxic elements along food chains and the decomposition of organic matter. To fill this gap, the present research, through the study of the chemical composition of four edible crops (leaves of lettuce, parsley and basil, and fruits of tomato) differently exposed to weak MFs (75 Hz; 1.5 mT), aimed at evaluating the overall effects of the exposure on ecosystem processes. In particular, several essential (B, C, Ca, Cu, K, Fe, Mg, Mn, Mo, N, Ni, P, S, Zn), beneficial (Co, Na, Se, Si) and non-useful (Al, As, Ba, Cd, Cr, Li, Pb, Sr, Ti, V) elements, together with chemical compounds and derived parameters (soluble sugars, starch, chlorophylls, flavonoids, anthocyanins, nitrogen balance index), indicators of plant metabolism and health, and litter decomposability traits (C/N, C/P), were analyzed. Notwithstanding the expected variations in the observed effects among species and MF exposure conditions, the obtained results highlight a general decrease in most of the studied parameters (with the exception of those related to litter decomposability), attributable to a lower absorption/accumulation of the studied chemical elements and to a reduced synthesis of metabolites. The largest average reduction was observed for the non-useful elements, which outweighs the reduction in essential and beneficial elements and provides for an important MFinduced effect, considering their toxic, persistent and biomagnificable characteristics. Similarly, the induced increases in C/N and C/P ratios indicate the production of litter more recalcitrant to the decomposition process, suggesting that weak MF treatments may be useful to enhance soil C storage and reduce CO2 emissions. Full article

Hypereutectic High Chromium Cast Iron (HHCCI) is a new type of corrosion-wear-resistant material developed from ordinary high chromium cast iron by increasing the chromium and carbon content and is often used in abrasive environments where wear and corrosion interact. The corrosion wear resistance of the HHCCI is related to the number, size, shape and distribution of carbides and the microstructure of the matrix. This paper reviews the research progress in improving the corrosion wear resistance of HHCCI from various aspects such as primary carbide refinement, heat treatment, deep cooling treatment and alloying, etc. Among the methods of refining primary carbides are modification, semi-solid treatment and current pulse treatment. In addition, we also analyze the potential of Cr, V, Nb, Mo, Mn, W, Ni, Cu, Si, N and other alloying elements to improve the corrosion wear resistance of HHCCI. The mechanism for improving the corrosion wear resistance of HHCCI is also explored in depth and research contents worthy of attention are proposed to further improve the corrosion wear resistance of HHCCI. In the future, the author believes that modification + alloying + heat treatment is the most potential application method to improve the corrosion wear resistance of HHCCI. The corrosion wear resistance of HHCCI can be further improved by refining the primary carbide (such as adding rare earth, Ti and other modified elements) + heat treatment (with cryogenic treatment) to improve the strength + alloying (such as adding low-cost, high-potential alloy elements such as N and Si) to improve the corrosion wear resistance of the matrix. Full article

With the rapid development of the economy, heavy metal soil pollution causes ecosystem deterioration and raises serious concerns. Topsoil samples (n = 205) were collected to investigate the pollution characteristics, risk levels, and pollution sources of heavy metals in the topsoil of eastern Tibet. Heavy metal contents, such as As, Hg, Pb, Cr, Mn, Mo, Ni, Cu, Zn, and Cd, in the soil were tested, and the potential sources were analyzed using correlational and principal component analysis. The results showed high content levels of Cd and Hg, which were 1.42 and 2.45 times higher than the background values of the Tibet Plateau at the beginning of this century, respectively. The enrichment factor (EF), geoaccumulation index (Igeo), and Nemero composite index (PN) showed that Cd and Hg were the main pollutants due to higher traffic flow and mining activities, but the pollution degree was generally not high and was relatively concentrated in the central and northern parts. The results of the principal component analysis showed that the heavy metals in the soil of eastern Tibet were mainly affected by natural factors and traffic factors, and mining activities and agricultural activities also played a certain role. Mn, Cr, Ni, As, Hg, and Cu were mainly affected by natural factors, while Pb, Zn, Cd, and Mo were affected by multiple factors, such as nature and traffic. Full article

Duplex stainless steel powders for laser additive manufacturing have not been developed extensively. In this study, the melts of a super duplex stainless steel X2CrNiMoCuWN25-7-4 (AISI F55, 1.4501) were atomized with different process gases (Ar or N₂) at different atomization gas temperatures. The process gas N₂ in the melting chamber leads to a higher nitrogen dissolution in the steel and a higher nitrogen content of the atomized powders. The argon-atomized powders have more gas porosity inside the particles than the nitrogen-atomized powders. In addition, the higher the atomization gas temperature, the finer the powder particles. The duplex stainless steel powders showed good processability during PBF-LB/M (Laser powder bed fusion). The gas entrapment in the powder particles, regardless of the gas chemistry and the gas content, appears to have a negligible effect on the porosity of the as-built parts. Full article