Copper Content Research Articles

К вопросу об использовании мелиоративных приемов в целях формирования биогеохимических барьеров

The amount of lands subject to contamination with heavy metal ions is increasing due to mining of minerals. Therefore, research on the use of various composite sorbents / ameliorants, which in combination with perennial plants can act as a biogeochemical barrier to the spread of heavy metal ions in the environment, is currently relevant. In the “soil–and-plant” system, use of the peat-and-diatomite ameliorant granulated on site in the direction of the man-made flow showed a high degree of survival of the awnless brome grass (Brōmus inērmis) compared with zero survival on the reference area. The dynamics of heavy metal accumulation in the plant biomass shows an increase in the content of copper and zinc, in comparison with the background values during the second year of research, while during the third year there is a decrease in the content of copper in the biomass from 235 to 40 mg / kg, with an increase in zinc content from 473 mg / kg to 510 mg / kg. The data obtained confirm the limits of metal fluctuations in the plant biomass established by previous researchers. At the peat-and-diatomite ameliorant sites, an increase in the concentration of Cu2+ and Zn2+ was also observed in comparison with the other survey locations, which indicates the possibility of using granular peat-and-diatomite ameliorant as a material to create a network of biogeochemical barriers perpendicular to the direction of the man-made flow.

Content of Cobalt and Copper in Organs, Tissues and Milk of Buffaloes

The materials for our research were the liver, muscles, blood of buffalo calves (up to one month of age) and the liver, muscles, blood and milk of buffaloes forcedly slaughtered on the farm itself and at the meat processing plant. Samples from the organs were taken into clean beakers, and the milk was milked into pre-prepared containers. Samples were taken in the spring-summer and autumn periods of 2021-2022. Based on the data obtained, the author concluded that the content of cobalt and copper in the organs and tissues of buffalo calves and female buffaloes varies widely. As studies have shown, the cobalt content in buffalo milk was 7.2±0.25 μg/l, and copper 71.35±3.3 μg/l.

Assessing the health risks of heavy metals and seasonal minerals fluctuations in Camellia sinensis cultivars during their growth seasons

The risk assessment of heavy metals in tea is extremely imperative for the health of tea consumers. However, the effects of varietal variations and seasonal fluctuations on heavy metals and minerals in tea plants remain unclear. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to evaluate the contents of aluminum (Al), manganese (Mn), magnesium (Mg), boron (B), calcium (Ca), copper (Cu), cobalt (Co), iron (Fe), sodium (Na), zinc (Zn), arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni), and antimony (Sb) in the two categories of young leaves (YL) and mature leaves (ML) of tea (Camellia sinensis) cultivars throughout the growing seasons. The results showed significant variations in the contents of the investigated nutrients both among the different cultivars and growing seasons as well. Furthermore, the average concentrations of Al, Mn, Mg, B, Ca, Cu, Co, Fe, Na, Zn, As, Cd, Cr, Ni, and Sb in YL ranged, from 671.58–2209.12, 1260.58–1902.21, 2290.56–2995.36, 91.18–164.68, 821.95–5708.20, 2.55–3.80, 3.96–25.22, 37.95–202.84, 81.79–205.05, 27.10–69.67, 0.028–0.053, 0.065–0.127, 2.40–3.73, 10.57–12.64, 0.11–0.14 mg kg−1, respectively. In ML, the concentrations were 2626.41–7834.60, 3980.82–6473.64, 3335.38–4537.48, 327.33–501.70, 9619.89–13153.68, 4.23–8.18, 17.23–34.20, 329.39–567.19, 145.36–248.69, 40.50–81.42, 0.089–0.169, 0.23–0.27, 5.24–7.89, 18.51–23.97, 0.15–0.19 mg kg−1, respectively. The contents of all analyzed nutrients were found to be higher in ML than in YL. Target hazard quotients (THQ) of As, Cd, Cr, Ni, and Sb, as well as the hazard index (HI), were all less than one, suggesting no risk to human health via tea consumption. This research might provide the groundwork for essential minerals recommendations, as well as a better understanding and management of heavy metal risks in tea.

Establishment of Indirect Competitive Enzyme-linked Immunosorbent Assay (ic-ELISA) for Copper ion (Cu2+) in Raw Meat Products

Adding an appropriate amount of copper to feed can promote the growth and development of livestock; however, a large amount of heavy metal copper can accumulate in livestock through the enrichment effect, which poses a serious threat to human health. Traditional Cu2+ detection relies heavily on complex and expensive instruments, such as inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS); thus, convenient and simple rapid detection technologies are urgently needed. In this paper, synthesized copper antigens were used to immunize mice and highly specific anticopper monoclonal antibodies were obtained, which were verified to exhibit high affinity and specificity. Based on the above antibodies, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was established for the rapid detection of copper content in pork. The standard inhibition curve of the method was obtained by antigen–antibody working concentration screening, in which the half inhibitory concentration (IC50) was 11.888 ng/mL, the limit of detection (LOD) was 0.841 ng/mL and the correlation coefficient R2 of the curve was 0.998. In the additive recovery experiment, the recovery rate ranged from 90% to 110%, and the coefficient of variation (CV) was less than 10%, indicating that the method achieved high accuracy and precision. Finally, the results of ic-ELISA combined with Bland-Altman analysis showed a high correlation with ICP-MS, and the correlation coefficient (R2) reached 0.990 when the copper concentration was less than 200 ng/mL. Thus, the ic-ELISA method exhibits high reliability.

Characterization of FeCoNiCr high-entropy alloys manufactured by powder metallurgy technique

This study explores the phase constitution, thermal behavior, magnetic characteristics, and mechanical properties of FeCoNiCrCux high-entropy alloys (HEAs) produced via powder metallurgy, focusing on varying copper ratios (0–20%). The investigation seeks to understand how the introduction of copper influences the phase composition and properties of FeCoNiCr HEAs, particularly regarding changes in phase structure and mechanical behavior. The phase constitution was analyzed using field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD). Thermal expansion and differential scanning calorimetry (DSC) were employed to study thermal behavior, while vibrating sample magnetometers (VSM) were utilized to assess magnetic properties. Mechanical properties were evaluated through hardness testing. The analysis reveals a shift in phase composition from a single-phase FCC structure to a dual-phase configuration comprising FCC and copper-rich FCC phases as copper content increases. Thermal and magnetic properties were characterized, demonstrating the alloy's behavior under varying conditions. Mechanical tests showed a decrease in hardness with increasing copper content. This study contributes to the understanding of how copper addition affects the phase constitution, thermal behavior, magnetic properties, and mechanical strength of FeCoNiCr HEAs. The observed changes in phase composition and mechanical properties offer insights for tailoring the properties of HEAs for specific applications.

Respiratory tract lining fluid copper content contributes to pulmonary oxidative stress in patients with systemic sclerosis

Background Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of the skin and internal organs, mostly affecting young and middle-aged women. Significant questions remain as to its pathogenesis, especially the triggers for the associated interstitial lung disease (SSc-ILD). We examined the extent to which SSc and SSc-ILD were related to oxidative stress and altered metal homeostasis at the air-lung interface. Methods In this case-control study, we recruited 20 SSc patients, of which 11 had SSc-ILD. Eighteen healthy individuals were recruited as age-matched healthy controls, for a total of 38 study participants. Low molecular weight antioxidants (ascorbate, urate and glutathione), metal transport and chelation proteins (transferrin and ferritin) and metals (Fe and Cu) concentrations, including a measure of the catalytically active metal pool, were determined in respiratory tract lining fluid (RTLF) collected by bronchoalveolar lavage from the SSc group and compared with healthy controls. Results In the SSc group, 14 individuals were of female sex (70%) and the median age was 57 years (range 35-75). We observed evidence of oxidative stress in the RTLFs of SSc patients, characterised by increased concentrations of glutathione disulphide (GSSG, P<0.01), dehydroascorbate (DHA, P<0.05) and urate (P<0.01). This was associated with elevated RTLF Fe (P=0.07) and Cu (P<0.001), and evidence of a catalytic metal pool, demonstrated by an enhanced rate of ascorbate oxidation in the recovered lavage fluid (p<0.01). Cu concentrations were significantly associated with the ascorbate depletion rate (r=0.76, P<0.001), and GSSG (r=0.38, P<0.05) and protein carbonyl (r=0.44, P<0.01) concentrations. Whilst these markers were all increased in SSc patients, we found no evidence for an association with SSc-ILD. Conclusions These data confirm the presence of oxidative stress in the airways of SSc patients and, for the first time, suggest that an underlying defect in metal homeostasis at the air-lung interface may play a role in disease progression.

Reservoir siltation and sediment characterization for reuse as construction material in a semi-arid area

Anibi S, Ellouze S, Zairi M. 2024. Reservoir siltation and sediment characterization for reuse as construction material in a semi-arid area. Lake Reserv Manage. 40:159–176. In this study, we investigated the siltation rate, evolution, and spatial distribution of sediments within the Siliana Dam reservoir, north-west Tunisia. We analyzed the geotechnical, chemical, mineralogical, and trace metal content properties of sediment samples collected from the reservoir. Additionally, we examined the potential valorization of reservoir sediments in road construction and the effects of hydrated lime treatment on their bearing characteristics. The Siliana dam reservoir is currently 50% silted up, and the sedimentation rate is approximately 1.52% per year. The sediments are mainly fine-grained, low organic with medium to high plasticity and high content of calcium carbonate. The sediments consist of calcite and quartz, with minor amounts of dolomite, hematite, and phyllosilicate minerals. Chromium, zinc, and copper contents in the sediments exceed environmental standards. The lime treatment improved the materials bearing capacity. Adding lime (5% by weight) resulted in an immediate bearing ratio of 26%, a higher ratio compared to the raw sediments. The study of the spatial and temporal evolution of sediment accumulation provides information to develop strategies for mitigating the accumulation of sediments. The sediment characterization evaluated the suitability of sediments to be used as construction materials, offering potential cost savings and contributing to informed decision-making for reservoir management.

Fertirrigação com cobre na cultura da beterraba em região semiárida

ABSTRACT Copper is an essential element for beet; however, it needs to be made available in adequate quantities since this nutrient, which is a heavy metal, can cause toxicity to plants and/or humans. This study aimed to evaluate the agronomic performance of beet fertigated with copper in a semi-arid region of Brazil. Two experiments were carried out in complete randomized blocks, with five treatments (0, 1.5, 3.0, 4.0, and 6.0 kg ha-1 of copper) and four replicates. In 2019, the copper content was within the adequate range for beet. In 2021, fertigation with copper above 0.8 kg ha-1 led to contents in the phytotoxicity range, which may explain the reduction in total and tuberous root dry mass accumulation. Fertilization with copper increased marketable yield in 2019 (17.32 t ha-1 at the dose of 3.9 kg ha-1 of copper), while, in 2021, there was no fit of the equations. Copper fertilization altered the tuberous root pH but did not influence the other tuberous root quality components. Plants fertilized with copper accumulated more copper in the leaves than in the tuberous root, with a maximum accumulation of 6.0 kg ha-1 of copper in 2019 and 2021. Fertilization with 3.9 kg ha-1 suits soils with low copper content.

Effect of Cu substitution on magnetic and photocatalytic properties of Mn–ZnFe2O4 nanoparticles

The citrate approach was employed to successfully synthesize Mn0.4Zn0.6−xCuxFe2O4 (MZCF) with a nanostructured shape. A thorough examination was conducted on the microstructural, magnetic, and optical properties of the nanoparticles obtained. The X-ray diffraction (XRD) patterns revealed that all of the compositions exhibit a high degree of single-phase spinel formation. The experimental findings indicate that the introduction of copper ions leads to a reduction in both lattice constant and porosity, while concurrently resulting in an increase in the theoretical X-ray and bulk densities. The analysis of UV–Vis spectroscopy indicated that MZCF exhibited a direct band gap falling within the range of 1.61–1.78 eV. The magnetic characteristics were assessed through the analysis of hysteresis plots. The introduction of copper (Cu) content leads to notable improvements in the saturation (Ms) and remanent magnetization (Mr) values, which range from 40.21 to 58.78 and 4.46–10.54 emu/g, respectively. The assessment of the microwave frequency response has verified the appropriateness of MZCF nanoferrites for application within the frequency spectrum spanning from 8 to 13 gigahertz. The nanoparticles exhibit improved magnetic properties, suggesting their potential appropriateness for applications involving high-frequency microwave absorption and switching. Furthermore, the nanoparticles Mn0.4Zn0.6Fe2O4 and Mn0.4Zn0.2Cu0.4Fe2O4 were subjected to analysis utilizing a solar light simulator in order to induce degradation of MB dye.

EFEKTIVITAS BIOCHAR TERHADAP KETERSEDIAAN UNSUR HARA MIKRO PADA ULTISOL

Biochar with a high organic matter composition is considered to be an ameliorant for Ultisol. Providing biochar as an ameliorant needs to be studied because it will cause an increase in micronutrients, most of which are excessive in Ultisol. This study aims to determine the effect of several levels of biochar dosage from corn cob as a base material on changes in micronutrients in Ultisol soil. This research was conducted in a greenhouse and in the Laboratory of Agrostology, Feed Industry and Soil Science, State Islamic University of Sultan Syarif Kasim Riau. Experiments with several doses of biochar as treatment, e.g., 0%, 5%, 10%, and 15% of the composition of the growing media were arranged in a Completely Randomized Design (CRD) with six replications. The parameters observed were the micronutrient content of Boron (B), Copper (Cu), Zinc (Zn), Iron (Fe) and Aluminum (Al). The experimental results showed that giving corn cob biochar with doses of 0.5%, 10% and 15% did not significantly change the levels of B, Cu and Zn Ultisol. Biochar at a dose of 10% significantly increased the soil Zn content and decreased Al-dd Ultisol solubility.

Identification of Metal Content in Water Samples from Natural Hot Water Sources in Ulumbu Desa Wewo Kecamatan Satar Mese Center Manggarai Regency

Tests have been conducted on the metal content of Calcium (Ca), Magnesium (Mg), Iron (Fe), Zinc (Zn), Copper (Cu), and Timbal (Pb), on samples of natural hot water Ulumbu Wewo Village Satar Mese Central Manggarai Regency. The research was conducted at the Joint Laboratory of the Faculty of MIPA Udayana University using Atomic Absorption Spectrometry (AAS). The data of the study showed samples of hot water from hot water bathing attractions in Ulumbu Village Wewo Satar Mese District of Central Manggarai Regency contain Ca, Mg, Fe, Zn, Cu, Pb which at each point was different. Calcium content at point 1: 1.6001 mg/L, point 2: 26.9995 mg/L. point 3: 22.3959 mg/L, point 4: 1.1805 mg/L, and point 5: 6.7990 mg/L; magnesium content at point 1: 9.8199 mg/L, point 2: 5.5111 mg/L, point 3: 3.2000 mg/L, point 4: 5.6998 mg/L, and point 5: 8.5598 mg/L; iron content at point 1: 71.8500 mg/L, point 2: 28.7231 mg/L, point 3: 14.3057 mg/L, point 4: 59.3206 mg/L, and point 5: 64.1108 mg/L; the zinc content was only found at point 1 of: 0.5423 mg/L; copper content at point 1: 1.9899 mg/L, point 2: 0.4967 mg/L, point 3: 0.5701 mg/L, point 4: 0.8975 mg/L, and point 5: 1.4201 mg/L and lead content at point 1: 2.7687 mg/L, point 2: 3.8499 mg/L, point 3: 4.4291 mg/L, point 4: 4.8486 mg/L, and point 5: 5.7186 mg/L.

Nanocrystalline (Cu0.5Ni0.5)yFe3−yO4 Ferrites: Synthesis and Characterization

Nanocrystalline materials with the composition of (Cu0.5Ni0.5)yFe3−yO4 and a spinel structure were synthesized by the auto-combustion sol–gel method. The materials were characterized by powder X-ray diffraction, Mössbauer spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and N2 physisorption. A decrease in the unit cell parameter and increase in the crystallite size with a decrease in the copper and nickel content in ferrites were evidenced. Mössbauer analysis determined that iron ions are in the 3+ states in all compositions. Transmission electron microscopy showed that synthesized ferrite materials consisted of nanoparticles with narrow size distributions. The catalytic properties of synthesized ferrites were studied in the reaction of ethyl acetate oxidation and methanol decomposition. The conversion of ethyl acetate and CO2 selectivity increased with temperature, and this effect was most pronounced for (Cu0.5Ni0.5)0.5Fe2.5O4, for which the main part of the particles possessed sizes below 10 nm, and the mean diameter was calculated to be 4.3 nm. The catalytic activity in the reaction of methanol decomposition was the highest for (Cu0.5Ni0.5)0.25Fe2.75O4, and it decreased with the increase in Cu and Ni content in the samples. The analysis of the samples after the catalytic test indicated significant reduction transformations within the catalysts. Under the reaction medium, the spinel phase decomposed through the formation of Hägg carbide.

Physico-Chemical, Sensory, and Nutritional Properties of Shortbread Cookies Enriched with Agaricus bisporus and Pleurotus ostreatus Powders

Mushrooms, due to their basic composition and the presence of numerous mycochemicals, can be used to improve various food matrices. The objective of this study was to determine the impact of replacing wheat flour (2%, 4%, 6% w/w) with mushroom lyophilisates from cultivated mushrooms—A. bisporus and P. ostreatus—on the technological quality, basic nutritional and elemental composition, antioxidant activity (ABTS, FRAP), total polyphenol content (TPC), and sensory evaluation of shortbread cookies. The functional properties of blended flours were also determined, such as bulk density (BD), water- and oil-holding capacity (WHC, OHC), swelling capacity (SW), and water solubility index (WSI). The results show that the amounts of protein, fiber, and ash were higher in cookies enriched with mushrooms than in control cookies. The enriched products, depending on the amount of mushroom powder used and the mushroom species, had a higher content of zinc, iron, magnesium, potassium, and copper. The increase in the addition of mushroom powder resulted in a significant (p < 0.05) increase in the TPC content and antioxidant properties. The use of composite flours contributed to a significant increase in hardness (at 6% mushroom powder) and a change in color parameters, with lower whiteness and a greater ΔE recorded for cookies with A. bisporus lyophilisate. In the sensory evaluation, the samples enriched with P. ostreatus powder received higher scores compared with control samples, while the cookies with A. bisporus flour were evaluated lower than the control.

Change in Monthly Mineral Content of Russian Thistle

This study was conducted in 2022 to determine the changes in the mineral content of Russian thistle according to its development periods on the land of Iğdır University Şehit Bülent Yurtseven Campus. In the 7-month period from April to October, the plant's N (Nitrogen), K (Potassium), P (Phosphorus), Mg (Magnesium), Na (Sodium), Ca (Calcium), Fe (Iron), Cu (Copper), Mn (Manganese) and Zn (Zinc) contents were determined. While the nitrogen content of the plant was high in April, May and June, there were decreases in nitrogen content in the following months. While the potassium content increased in May and June compared to April, there were decreases in potassium content in July and the following months. As the development of the plant progressed, there was a decrease in the phosphorus content. While magnesium content was highest in April and September, it was low in other months. Calcium content was highest in April and May and lowest in August. While the sodium content increased until June, there were decreases in the following months. While the iron content increased until July, there were decreases in the following months. Copper content reached its highest level in July and October. Manganese content was highest in September and lowest in July. Zinc content decreased with the advancement of plant development.

Influence of copper and silicon on phase transformations in the iron – carbon system

Influence of copper and silicon on phase transformations in the iron – carbon system

Background levels of heavy metals in the water of Khadzhibey estuary

In the Odesa region, heavy metal contamination of fishery water bodies is a pressing problem. The accumulation of heavy metals in fish depends on the physiological and biochemical activity of the organism and the physical and chemical parameters of the water body. Most heavy metals enter the fish's body through the gills, skin, and digestive organs. Copper, zinc, and plumbum accumulate in the skin, gills, and liver, while cadmium and mercury accumulate in the kidneys. The level of heavy metal pollution in the water of the Khadzhibey estuary was measured and determined in 2022–2023. The following methods were used to determine the content of heavy metals in water: atomic emission spectroscopy using an EMAS-200 CCD instrument to determine cadmium, copper, zinc, and plumbum; cold vapor atomic absorption spectroscopy using the “Julia-2M” method to determine the content of mercury. Toxicological studies of water were carried out in the water hygiene and ecology laboratory of the Ukrainian Research Institute of Transport Medicine and at the Department of Veterinary Hygiene, Sanitation, and Expertise of Odesa State Agrarian University. The study found that the content of heavy metals in the water of the Khadzhibey estuary is not constant and fluctuates depending on the season. The maximum levels of heavy metals are observed in summer (plumbum and cadmium) and autumn (zinc, copper and mercury). It was found that cadmium, plumbum, copper, and mercury content does not exceed the maximum permissible levels for marine fisheries. The zinc content in the water of the Khadzhibey estuary exceeds the maximum permitted concentration by 2.65%. The zinc content in the studied water samples is a stress factor affecting the meat quality of common carp (Cyprinus carpio) and round goby (Neogobius melanostomus).

Development of Printed Circuit Boards with High Thermal Conductivity and Low Thermal Expansion by Applying Cu-Mo Composite Materials

In recent years, electronic devices are strongly required to be smaller, lighter, and more powerful. As a result, mounted components have become smaller, more powerful, and denser, and the heat generation density on printed circuit boards (PCBs) has increased. Since rising component temperatures can lead to component failure, efficient heat removal from the generated heat has become an urgent issue. Since general PCBs have low thermal conductivity, when high heat dissipation is required, methods to increase the thermal conductivity of PCBs have been employed by increasing the copper (Cu) content in the PCB or by placing an aluminum (Al) alloy in the inner layer. However, while Cu and Al have high thermal conductivity, they also have high coefficients of thermal expansion (CTE) and young’s modulus, and the CTE of a PCB with increased thermal conductivity using these materials is high. If the thermal expansion difference between the PCB and mounted components is large, reliability against heat cycles cannot be obtained. Therefore, we have focused on copper-molybdenum (CuMo) composite materials with high thermal conductivity, high elastic modulus, and low thermal expansion. We have been utilizing Cu-Mo for the development of our PCBs and fabricated multilayered CuMo composite PCBs; therefore, this report will focus on the results regarding thermal characterization of prototype PCBs.

A Cu(Ⅱ)-eluting coating through silk fibroin film on ZE21B alloy designed for in situ endotheliazation biofunction

In the cardiovascular field, coating containing copper used to catalyze NO (nitric oxide) production on non-degradable metal surfaces have shown unparalleled expected performance, but there are few studies on biodegradable metal surfaces. Magnesium-based biodegradable metals have been applied in cardiovascular field in large-scale because of their excellent properties. In this study, the coating of copper loaded in silk fibroin is fabricated on biodegradable ZE21B alloy. Importantly, the different content of copper is set to investigate the effects of on the degradation performance and cell behavior of magnesium alloy. Through electrochemical and immersion experiments, it is found that high content of copper will accelerate the corrosion of magnesium alloy. The reason is the spontaneous micro-batteries between copper and magnesium with the different standard electrode potentials, that is, the galvanic corrosion accelerates the corrosion of magnesium alloy. Moreover, the coating formed through silk fibroin by the right amount copper not only have a protective effect on the ZE21B alloy substrate, but also promotes the adhesion and proliferation of endothelial cells in blood vessel micro-environment. The production of NO catalyzed by copper ions makes this trend more significant, and inhibits the excessive proliferation of smooth muscle cells. These findings can provide guidance for the amount of copper in the coating on the surface of biodegradable magnesium alloy used for cardiovascular stent purpose.

Effect of cuprum proteinate on blood parameters in broiler chickens

The data obtained during the scientific and economic experiment show that the replacement of copper sulfate with copper proteinate in broiler chickens, even in smaller doses, did not significantly affect hematological and biochemical blood parameters. Some increase in the total level of albumins and globulins, the activity of aspartate aminotransferase and alanine aminotransferase, and the content of calcium, phosphorus and copper in blood serum was noted. Introduction of cuprum proteinate to compound feed to broiler chickens of the third experimental group in doses of 13.9; 12.6 and 9.0 g/t (on average for 42 days – 12.5 g/t) contributed to a probable increase in total protein by 14.2 % (Р < 0.05) on the 30th day of the experiment and by 12.3 % (Р < 0.05) on the 42nd day of the experiment compared to the control group. At the same time, the level of albumins increased by 11.9 % (Р < 0.05) and 15.8 % (Р < 0.05), and globulins by 12.0 % (Р < 0.05) and 10.7 %, respectively. This fact shows that reducing the dose of cuprum proteinate has a positive effect on protein synthesis, activation of albumin and globulin synthesis occurs, which reduces the load on the immune system of broiler chickens and has a positive effect on protein metabolism. On the 42nd day of the experiment, the calcium content in the blood of all groups increased, but in the experimental groups it was higher than the control indicator in the second group by 4.8 % and by 5.6 % in the third experimental group. Regarding the level of Phosphorus in the blood serum of experimental groups of broiler chickens, its amount increased to 1.85–1.96 mmol/l on the 42nd day. The content of cuprum in the blood of broiler chickens, which were fed cuprum proteinate as part of compound feed, was probably higher than the indicator of the control group. Chickens of the second experimental group, which were fed cuprum proteinate in quantities of 18.2; 16.8 and 12.0 g/t of compound feed exceeded their counterparts by 14.0–16.3 % (Р < 0.05). Broiler chickens of the third experimental group, which were added to compound feed with cuprum proteinate in doses of 13.9, 12.6 and 30 g/t, prevailed on day 30 of the experiment by 18.8 % (Р < 0.01), and on day 42 day by 18.9 % (Р < 0.01). A higher level of Calcium and Phosphorus in the blood serum of experimental broiler chickens indicates an increase in the resistance of the bird to infections and better mineralization of bone tissue. Feeding of cuprum proteinate to broiler chickens makes it possible to reduce the dose of the trace element in compound feed, which reduces the burden on the bird's body and increases the biological availability of mineral compounds.

Preparation of graphene supported copper composite materials and study on the catalytic activity of phenol hydroxylation

The hydroxylation of phenol to synthesize dihydroxybenzene (DHB) has recently attracted considerable attention due to its inherent advantages, including its simplicity in industrial applications, environmental friendliness, and remarkable selectivity towards DHB. The hydrothermal method was used to prepare graphene supported copper composites (Cu/GNS) with excellent catalytic properties, which were applied in the phenol hydroxylation for DHB preparation. Cu/GNS with controllable copper content were successfully obtained, achieving the homogeneous dispersion of copper ions on the graphene surface while preventing graphene agglomeration. During catalysis, graphene serves as an electron transport conduit, enhancing the exposure of reactive active sites and facilitating the generation of hydroxyl radicals. The π-π interactions between graphene and phenol enhance the propensity for collision between phenol and hydroxyl radicals. The total selectivity of DHB reached 98.4%, and the phenol conversion reached 85.1%. The composites exhibited high stability, with 80.5% phenol conversion and 93.7% DHB total selectivity even after five reuse cycles.