Copper Citrate Research Articles

A new strategy for utilization of gasification ash: Manganese oxides-modified activated carbon for efficient copper citrate removal

To address the challenges posed by solid waste generated from coal gasification ash, a pyrolysis self-activation method was employed to prepare activated carbon by gasification ash, followed by the modification with manganese oxide to enhance its adsorption performance. Subsequently, the removal efficiency and mechanism for copper citrate were investigated. The results demonstrated the successful preparation of manganese oxides modified gasification ash-derived activated carbon (GAC-MnOx), exhibiting a specific surface area of 158.3 m2/g and a pore volume of 0.1948 cm³/g. The kinetic process could be described by the pseudo-second-order kinetic model (R2 = 0.958). High removal efficiency and low concentration of dissolved Mn were observed within the pH range of 3–10, where the adsorption capacity of GAC-MnOx for copper citrate exhibited an inverse relationship with pH. Notably, the fitting results of the Langmuir model demonstrated that the maximum adsorption capacity of GAC-MnOx for copper citrate is determined to be 7.196 mg/g at pH 3. The adsorption capacity of GAC-MnOx was found to be significantly reduced to 0.26 mg/g as the pH decreased below 2, potentially attributed to the dissolution of Mn. The findings of the Dual-Mode model demonstrated that the copper citrate removal mechanism by GAC-MnOx involved both surface adsorption and precipitation processes as follows: the porous structure of activated carbon enables physical adsorption of copper citrate, the MnOx or oxygen-containing functional groups establish chemical bonds with copper citrate and subsequently precipitate onto the surface of the adsorbent. The physical adsorption remains predominant in the removal of copper citrate, despite a gradual decrease in its proportion with increasing pH and equilibrium concentrations. Moreover, the X-ray photoelectron spectroscopy results indicated that copper citrate might be oxidized by MnOx to release copper ions and be retained on the surface of the adsorbent, meaning the adsorption efficiency of Cu(II)-Cit by GAC was enhanced through MnOx oxidation. This study could provide a new strategy for the high-value resource utilization of gasification ash.

In Situ Copper Coating on Silicon Particles Enables Long Durable Anodes in Lithium-Ion Batteries.

Addressing the significant obstacles of volume expansion and inadequate electronic conductivity in silicon-based anode materials during lithiation is crucial for achieving a long durable life in lithium-ion batteries. Herein, a high-strength copper-based metal shell is coated in situ onto silicon materials through a chemical combination of copper citrate and Si-H bonds and subsequent heat treatment. The formed Cu and Cu3Si shell effectively mitigates the mechanical stress induced by volume expansion during lithiation, strengthens the connection with the copper substrate, and facilitates electron transfer and Li+ diffusion kinetics. Consequently, the composite exhibits a reversible specific capacity of 1359 mA h g-1 at 0.5 A g-1 and maintains a specific capacity of 837 mA h g-1 and an 83.5% capacity retention after 400 cycles at 1 A g-1, surpassing similar reports on electrochemical stability. This facile copper plating technique on silicon surfaces may be used to prepare high-performance silicon-based anodes or functional composites in other fields.

Reductive decomplexation of Cu(II)-complexes from copper wastewater by zero-valent aluminum material

In order to effectively remove the extremely stable Cu(II)-complexes, decomplexation is typically required, with previous efforts focusing on the destruction or substitution of organic ligands. Now, we have a new concept that if starting with Cu(II) group and reducing it directly from the complex state, the reductive decomplexation of Cu(II)-complexes may be attained along with the recovery of Cu(II) to Cu0. In this study, for the first time, we introduced a carbon-modified zero-valent aluminum material (C@mZVAl) for one-step reductive decomplexation of Cu(II)-complexes. It was found that 96.84% Cu-EDTA removal and 91.99% Cu0 recovery could be reached. Furthermore, this efficient reductive decomplexation approach was also applicable to other complexes such as copper pyrophosphate, copper tartrate and copper citrate. SEM-EDS, XPS and XRD showed that Cu0 appeared on the material's surface, providing evidences of successful reduction of complexed Cu(II). Cu-EDTA was firstly adsorbed because of the carbon’s adsorption, and then accepted the electrons released from the powerful reducer zero-valent aluminum to accomplish reductive decomplexation. Furthermore, without any pretreatment, two real industrial copper-plating wastewater containing copper pyrophosphate and Cu-EDTA were treated and the total Cu recovery rates were both achieved up to 98.00%. In conclusion, our innovative approach offers a novel method of decomplexation for the efficient recovery of reusable metal products from complexed metal wastewater through a direct reduction reaction.

Influence of Organic and Inorganic Compounds of Various Metals on the Synthesis of Polysaccharides by the Medicinal Mushroom Trametes versicolor.

To date, basidiomycetes are considered to be promising objects of biotechnology, due to a number of biologically active compounds, such as polysaccharides and triterpenes. These compounds have a high therapeutic potential and demonstrate immunomodulatory, antiviral, and antifungal activities. The purpose of this study was to study the effect of various concentrations of metal citrates and sulphates on the content of exo- and endopolysaccharides of the fungus Trametes versicolor. The mycelium was grown by deep cultivation on a semisyntheticglucose-peptone-yeast medium with different contents of zinc, copper, and manganese salts, after which the extraction and measurement of the concentration of polysaccharides were carried out. The results obtained showed that copper citrate at a concentration of 4 mg/L had the greatest positive effect on biomass yield. The intensity of biomass growth on a nutrient medium with copper citrate increased by 80%. Zinc citrate increased the content of exopolysaccharides by 29% compared to the medium without metal salts. When manganese citrate was added to the medium, the productivity of synthesis decreased, but an increase in the growth rate of mycelium biomass was observed. Sulphates of these metals led to a decrease in the productivity of exopolysaccharide synthesis by 12% for zinc and 35% for manganese. The addition of both copper citrate and copper sulphate to the medium led to a decrease in the synthesis productivity by 66 and 24%, respectively. The introduction of both citrates and sulphates of these metals into the culture medium led to an increase in the percentage of endopolysaccharides in the mycelium of the fungus. Copper citrate enhances Trametes versicolor biomass by 80%. Zinc citrate increases exopolysaccharide content by 29%. Copper sulphate optimizes endopolysaccharide production.

Methyl levulinate synthesis from rice husk employing e-waste derived silica supported nano CuO–CdSO4 photocatalyst: Assessment of production environmental impacts, engine performance and emissions

Applications of E-waste recovered silica (support) and copper citrate (precursor) for the synthesis of nano CuO–CdSO4 doped photocatalyst (NCCP) for subsequent employment in sustainable conversion of rice husk (RH) to drop-in biofuels viz. methyl levulinate (ML) have been explored. The prepared NCCP (low Eg = 2.0 eV) was employed for alcoholytic depolymerization (AD) to produce ML from holocellulose (HOC) extracted from RH through infrared assisted delignification. Taguchi orthogonal design predicted the optimal values of the AD viz. HOC: Water (1:5 w/w), NCCP concentration (1 wt%), HOC: methanol (1:30 w/w) and AD time (125 min) rendering 96.97% ML yield deploying combined ultrasonication-UV energies at 60 °C; saving 30% energy compared to conventional heating system. Noticeably, this is the first insightful investigation on the application of ML as a diesel additive demonstrating significant diminutions (25.92% and 83.33% for CO and HC) in harmful emissions. The LCA of the overall ML synthesis indicates remarkable reduction in environmental pollution with 63.63% and 66.66% mitigations in GWP and ecotoxicity respectively. Thus, a sustainable ML synthesis protocol encompassing the development of E-waste derived nanophotocatalyst through conversion of rice husk and its successful use as a diesel additive could be established.

Synthesis of copper (II) citrate and evaluation ofits in vitro antifungaland antibacterial activities, and the suitability of using this chemicalas a plant protection agent

In this paper, copper (II) citrate Cu3(C6H5O7)2 was successfully synthesised in an aqueous solution. The factors for the synthesis process such as temperature and molar ratio of the reactants were investigated. The structural, properties and composition characteristics of the elements were investigated and evaluated by X-ray diffraction pattern (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and UV-Vis spectroscopy. The yield of the copper (II) citrate in the reaction was 82.46% at the molar ratio of the CuSO4/C6H5Na3O7 of 1.5/1 at 70oC. The in vitro results showed that copper (II) citrate at a concentration of 1,000 ppm inhibits the mycelial growth of Sclerotium rolfsii and Fusarium oxysporumwith control values ranging from 19 to 53% after 2 days of incubation. Besides, it strongly suppressed the plant bacterial pathogens Xanthomonas axonopodis (bacterial strain causing citrus canker), Ralstonia solanacearum(bacterial wilt of tomato), and Clavibacter michiganensis subsp. michiganensis (cause of bacterial wilt and canker of tomato). These results suggested that copper (II) citrate can be used as a promising fungicide/bactericide to control fungal and bacterial diseases on citrus and tomato plants.

One‐pot facile synthesis of Cu‐SAPO‐34 via addition of tetraethylenepentamine and its enhanced catalytic activity in selective catalytic reduction of NOx with NH3

AbstractBACKGROUNDA series of Cu‐SAPO‐34 samples were prepared with different copper sources and addition of tetraethylenepentamine (TEPA) by a one‐pot method, which were applied for selective catalytic reduction of NOx with ammonia (NH3‐SCR).RESULTSVarious measurements were carried out to investigate the effect of TEPA addition and copper sources used on sample properties. The results indicated that Cu‐SAPO‐34 obtained with the addition of TEPA using copper citrate (Cu‐SAPO‐34‐TC) displayed over 90% NOx conversion at 150–500 °C and excellent H2O and SO2 resistance in NH3‐SCR. This is because the addition of TEPA can control the formation of isolated Cu2+ species located at the junction of D6R in CHA cage, Site (I), which is regarded as a more easily approachable site to adsorbates (NH3 and NO) than others, thus leading to the excellent NH3‐SCR performance. Further study demonstrated that the Cu‐SAPO‐34‐TC catalyst shows much wider temperature window and more hydrothermal stability due to a greater amount of surface isolated Cu2+, fewer Si islands and more Al(IV) species.CONCLUSIONSThe excellent activity of the Cu‐SAPO‐34‐TC catalyst can be attributed to the addition of TEPA, which is beneficial for controlling the isolated Cu2+ at Site (I) as well as inhibiting the aggregation of CuO species. Various characterizations also confirm that more surface Cu2+ can be produced using copper citrate as copper source. © 2022 Society of Chemical Industry (SCI).

Effects of copper citrate on physiological-biochemical parameters of ejaculate of sire boars

Revealing peculiarities of the course of physiological and biochemical processes in the formation of parameters of ejaculate allows effective correlation of biological completeness of spermatozoids based on the use of chelate compounds of limiting microelements, particularly copper. The study was focused on determining changes in processes of spermatogenesis during correction of mineral nutrition. In the experiment, we used adult boars of the same age, live weight and quality of ejaculates. They consumed copper citrate during the 45 day experiment in doses higher than the norm by 10% (1.5 mg per 1 kg of combined feed) and 20% (3 mg per 1 kg of combined feed) compared with the control. We determined difference in the effects of different doses of copper citrate on the formation of parameters of ejaculates in sire boars. Addition of the mineral additive to the feed in the doses 10% exceeding the norm promoted increase in the parameters of functional activity of spermatozoids – mobility and survival – on day 45 of the intake, which occurred against the background of acceleration of peroxidation processes (increase in the concentration of thiobarbituric acid of active compounds) and activation of the system of antioxidant protection – increase in the activity of superoxide dismutase and decrease in the level of catalase in the sperm. At the same time, we observed increase in the morphometric parameters of spermatozoids – general length, width, length and volume of the head. On day 30, sire boars that had been consuming copper citrate in the amounts 20% above the norm were observed to have increase in concentration of spermatozoids, their mobility and survivability, though a decrease was seen in the morphometric parameters of the gametes. Further intake of this element caused increase in the amount of abnormal forms of spermatozoids. Under the action of this additive, we determined increase in the amount of metabolites of lipid peroxidation – conjugated dienes and thiobarbituric acids of active compounds, and also weakening of the system of antioxidative protection – decrease in the content of reduced glutathione and accumulation of dehydroascorbic acid. Thus, the intake of copper citrate in the amounts of 10% above the norm facilitated morpho-functional parameters of spermatozoids by activating the system of antioxidant protection. It would be promising to conduct further research to determine the effects of copper citrate on the processes of activation and capacitation of spermatozoids and fertilization of oocytes in in vivo and in vitro conditions.

Fabrication and characterization of pyrolytic carbons from phenolic resin reinforced by SiC nanowires with chain-bead structures

SiC/SiO2 nanowires (NWs) were successfully synthesized via a simple chemical vapor deposition method at 1200 °C under an argon atmosphere by using phenolic resin (PF) and silicon (Si) and then catalyzed by copper citrate. The obtained SiC/SiO2 NWs as-calcined at 1200 °C had a chain-bead structure, and the SiC nanowire was wrapped by amorphous SiO2 nanospheres: The diameter of the SiO2 bead was in the range of 175–250 nm; the length of the SiC chain was 375–500 nm, and the diameter was 83 nm. The copper phase derived from copper citrate could dissolve with Si to form a Cu/Si alloy, and it could reduce the melting point of the Si particle and generate higher amount of SiO. The growth mechanism of the Cu-catalyzed SiC/SiO2 NWs was vapor-solid (V–S). The strength and oxidation resistance of the PF pyrolysis carbons were reinforced by SiC/SiO2 NWs. The cold crushing strength (CCS) of the PF pyrolysis carbons calcined at 1200 °C and 1300 °C increased from 0.08 MPa to 0.64 MPa and 0.36 MPa to 1.81 MPa, respectively. The starting and ending temperatures of weight loss temperatures of PF pyrolysis carbons were delayed from 513 °C and 678 °C to 568 °C and 723 °C, respectively. The enhancements in the mechanical properties and oxidation resistance properties of the PF pyrolysis carbons were because the C–SiC bonding phase of the PF resisted external stress and oxygen effectively.

Control of Riboscyphidia sp. (Ciliate) Infection in Asian Sea Bass (Lates calcarifer), Cultivated in the Red Sea

Sessiline ciliates live as eco commensals (low numbers) and parasites (high numbers) on different hosts, like mollusks copepods, mysids and fish. Riboscyphidia ecto-protozoan is moderately pathogenic but high numbers of it on the gills can physically prevent gas exchange. The present study aimed to describe the epizoic ciliates Riboscyphidia found on the Red Sea cultured Asian sea bass and obtain more information on the Epidemiology of the parasite with special references to control and histopathological examination of naturally infected sea bass.The occurrence of epizoic ciliates on the adult Asian Sea bass. About 100 Asian sea bass were collected by the fishing net at a private marine fish farm at Ismailia governorate and transferred to the hydrobiology laboratory at National Research Centre. A parasitological and histopathological study of epizoic sessile ciliate species was done. ANOVA test was used for Statistical analysis.Riboscyphidia sp. was found and isolated after parasitological examination of investigated adult's Asian sea bass. The prevalence of Riboscyphidiosis was 64%. Sessile ciliates were found on gills, skin and fins. The clinical signs of Riboscyphidiosis were respiratory distress, flashing and off food. Histopathological alterations in naturally infested Asian sea bass were investigated.The treatment of choice of Riboscyphidiosis was prolonged immersion by Copper citrate with a dose of 0.56 mg mL-1 for 7 days.

Прооксидантно-антиоксидантний гомеостаз та відтворювальна здатність кнурів-плідників за впливу цитрату міді

Peroxide oxidation processes play a leading role in ensuring the motility, survival and fertilizing ability of sperm. A special role is given to limiting antioxidants (vitamins, amino acids, microelements). Therefore, the development of standardized feeding programs to provide antioxidant nutrition is one of the effective methods of reproductive biotechnology. The aim of the study was to determine the effect of copper citrate on the quality of sperm production and the formation of prooxidant-antioxidant homeostasis in sperm of boars. The experiment used adult boars of a large white breed, analogs in age, live weight and quality of sperm products. Experimental groups were fed copper citrate above the norm by 10% and 20%. It has been determined that feeding combined feed to boars with the addition of this compound in an amount of 10% above norm probably increases the weight of ejaculate by 12.5% (P<0.05), the sperm motility and survival by 6.5% (P<0.01) and 13.5% (P<0.001), respectively. Such changes in sperm occur against the background of an increase in SOD activity by 80.6% (P<0.05), a decrease in catalase by 43.5% (P<0.05), a slowing down of peroxidation processes — a decrease in diene conjugates and TBA-active compounds. The additional introduction to the diet of copper citrate by 20% more than normal increases the concentration of spermatozoa by 13.2% (P<0.01), the number of live spermatozoa by 20.7% (P<0,01), with a simultaneous decrease in their survival, due to the acceleration of peroxidation processes — an increase in the content of diene conjugates, TBA-active compounds and DAA and a decrease in reduced glutathione. It has been found out that the fertilizing ability of sperm significantly depended on the amount of fed microelement. Sows inseminated with sperm of boars receiving copper supplement in the diet by 10%, had higher fertility rates by 7.1%, multifertility by 3.6%, and a litter weight at weaning by 8.8%. The additional administration of copper citrate reduced the fertility of sperm by 20%, as the fertility rate of sows of III group was the lowest and was 7.7% and 14.3% lower compared to I and II groups. A similar trend occurred in terms of high fertility, a litter weight at birth and weaning. Therefore, the additional feeding of a small amount of copper has a positive effect on the functional activity of sperm and the processes of normal fertilization, growth and development of embryos and newborn piglets by optimizing the formation of prooxidant-antioxidant homeostasis.

Effects of flame retardants integrated with citrate and ammonium polyphosphate on thermal stability and flame retardancy of thermoplastic polyurethane elastomer

Three citrates, which incorporate cobalt citrate (CoC), copper citrate (CuC), and yttrium citrate (YC), were combined with ammonium polyphosphate (APP) as a flame retardant to improve the flame retardancy and thermal stability of thermoplastic polyurethane (TPU). The cone calorimeter test (CCT) results demonstrated that the PHRR (peak heat release rate) values of TPU‐2, TPU‐3, and TPU‐4 were decreased from 271.4 kW/m2 for TPU‐1 to 188.0, 256.9, and 219.0 kW/m2, respectively. Besides, compared with TPU‐1, the release of CO and CO2 of TPU composites that containing citrate were decreased. The limiting oxygen index (LOI) value for TPU‐1 (containing 8.0 wt% APP) was 26.5% while that of TPU‐4 was increased to 27.5% and reached to V‐0 rating on the vertical burning test. Thermogravimetric analysis (TG) indicated that containing both APP and citrate accelerated the degradation of TPU composites but increased the char residue. In detail, the char residue of TPU‐0 was 6.3 wt% at 685°C, while that of TPU‐3 was reached to 45.2 wt% at N2 atmosphere. Laser Raman spectroscopy (LRS) showed that the degree of graphitization of TPU composites had been increased after adding the citrates. X‐ray photoelectron spectrometer (XPS) and gas chromatography/mass spectrometry (GC‐MS) illustrated that citrate and APP exerted barriers effect in the condensed phase. This work provided a new way of flame retardant that integrated with citrate and APP for TPU composites.

A flexible fibrous membrane based on copper(II) metal-organic framework/poly(lactic acid) composites with superior antibacterial performance.

A flexible antibacterial fibrous membrane employing high antibacterial efficiency has great potential in healthcare applications. Herein, a three-dimensional copper(ii) metal-organic framework [Cu2(CA)(H2O)2, Cu-MOF-1] and poly(lactic acid) (PLA) composite fibrous membrane was prepared through a facile electrospinning method. The sphere-like Cu-MOF-1 was rapidly synthesized by a microwave-assisted hydrothermal reaction of Cu(ii) salts with citric acid (H4CA) in the presence of polyvinyl pyrrolidone (PVP). The surface morphology, thermal stability, mechanical properties and hydrophilicity test of the as-prepared Cu-MOF-1/PLA fibrous membrane were studied systematically. Compared with commercial copper nanoparticles (Cu-NPs), citric acid and copper citrate, Cu-MOF-1 showed higher antibacterial properties with the bacteriostatic rates of 97.9% and 99.3% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively, when the used dose was 250 μg mL-1. The Cu-MOF-1/PLA fibrous membrane also exhibited outstanding bactericidal activities against E. coli and S. aureus with the antibacterial rates up to 99.3% and 99.8%, respectively. Mechanism investigation indicated that the slowly released Cu2+ ions could destroy the microenvironment of bacteria cells and destroy the integrity and permeability of the cell membrane, leading to enzyme inactivation. Therefore, the as-prepared flexible fibrous membrane will advance progress toward developing a broad spectrum antibacterial textile for healthcare protection related applications.

Gene Expression Analysis of Three Putative Copper-Transporting ATPases in Copper-Tolerant Fibroporia radiculosa.

Copper tolerance of brown-rot basidiomycete decay fungi can lessen the efficacy of copper-containing wood preservatives for wood products in-service. The purpose of this study was to evaluate wood mass loss and differential expression of three genes that have putative annotations for copper-transporting ATPase pumps (FIBRA_00974, FIBRA_04716, and FIBRA_01430). Untreated southern pine (SP) and SP treated with three concentrations of ammoniacal copper citrate (CC, 0.6, 1.2, and 2.4%) were exposed to two copper-tolerant Fibroporia radiculosa isolates (FP-90848-T and L-9414-SP) and copper-sensitive Gloeophyllum trabeum isolate (MAD 617) in a 4-week-long standard decay test (AWPA E10-19). Decay of copper-treated wood was inhibited by G. trabeum (p = 0.001); however, there was no inhibition of decay with increasing copper concentrations by both F. radiculosa isolates. Initially, G. trabeum and one F. radiculosa isolate (L-9414-SP) highly upregulated FIBRA_00974 and FIBRA_04716 on copper-treated wood at week 1 (p = 0.005), but subsequent expression was either not detected or was similar to expression on untreated wood (p = 0.471). The other F. radiculosa isolate (FP-90848-T) downregulated FIBRA_00974 (p = 0.301) and FIBRA_04716 (p = 0.004) on copper-treated wood. FIBRA_01430 expression by G. trabeum was not detected, but was upregulated by both F. radiculosa FP-90848-T (p = 0.481) and L-9414-SP (p = 0.392). Results from this study suggest that all three test fungi utilized different mechanisms when decaying copper-treated wood. Additionally, results from this study do not provide support for the involvement of these putative gene annotations for copper-transporting ATPase pumps in the mechanism of copper-tolerance.

INFLUENCE OF NEUROTROPIC AND METABOLIC DRUGS ON STRUCTURAL AND FUNCTIONAL STATE OF LIPID MATRIX OF THE CELL MEMBRANE

Lately, more and more often to stimulate the reproductive function of animals people use biochemical products, which are based on neurotropic and metabolic compounds and trace elements of nanobiotechnological origin. In order to new biotechnical drugs search and development, and more effective and safe combinations of dietary supplements in them, one should know Biochemical mechanisms of membranotropic action of these substances on a cell. Since these substances can lead to physiological changes in the cell and trigger nonspecific toxic effects on the body of animals depending on dose and period of action. The article presents the results of studies on the effects of neurotropic and metabolic drugs on structural and functional state of lipid matrix of the cell membrane. In experiment were used four drugs: hlutam 1-M (Sodium Glutaminate), stymulin (Sodium Glutaminate, Sodium Succinate), nanovulin-VHR (Sodium Glutaminate, Sodium Succinate, Copper Citrate), nanovulin-R (Sodium Glutaminate, Sodium Succinate, L-arginine, Copper Citrate). The main task of the experiment was to investigate the concentration effects and primary mechanisms of membranotropic influence of the components of investigated drugs in the range of physiological concentrations of the active substance on the structural and functional state of the lipid matrix of cell membranes. According to research results, it was found that Sodium Glutaminate, which is part of all the investigational drugs, affects the polarity of the hydrophobic zone of the membrane and increases the polarity of the lipid surround. An application of Sodium glutaminate with Succinate in same drug (stimulin, nanovulin-VHR, nanovulin-R) reduces the destructive effects of Sodium Glutamate on the lipid membrane of cells. Also, it should be noted that Copper Citrate in combination with Glutaminate and Succinate (nanovulin-VHR, nanovolin-R) excludes the membrane-stabilizing and membrane-disruptive effects of their influence on the structure of lipid packing in the bilayer. From the results of the research we can suggest, that aquachelates penetrate the hydrophobic lipid bilayer zone, as evidenced by the total fluorescence quenching of pyrene.

Copper supported on acid-activated vermiculite as an efficient and recyclable catalyst for the Biginelli reaction: a green approach

AbstractThe synthesis of copper citrate complex supported on acid-activated vermiculite was investigated with a view to preparing an efficient, mild, robust and recyclable catalyst for the Biginelli reaction. The new catalyst was characterized by X-ray fluorescence (XRF), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). Copper citrate supported over activated vermiculite (AAVrm-Cu2) showed good catalytic activity in the synthesis of 3,4-dihydropyrimidinones. The catalyst can be separated easily from the reaction mixture by filtration and retains its catalytic activity for up to five cycles of reaction with no apparent decrease in yield.

Differential Expression of a Putative Copper Homeostasis CutC Gene in Fibroporia radiculosa During Initial Decay of Copper-Treated Wood

Abstract Living organisms require copper for several cellular processes. Yet intracellular concentrations of copper must be regulated to avoid toxicity. Not much is known about mechanisms of copper regulation in wood decay fungi. However, one putative annotation for a copper homeostasis CutC gene (FIBRA_00129), found in other brown-rot wood decay fungi, has been annotated in Fibroporia radiculosa. The aim of this study was to evaluate wood mass loss and differential expression of FIBRA_00129 during initial decay of untreated and copper-treated wood by two copper-tolerant F. radiculosa isolates (FP-90848-T and L-9414-SP) compared with copper-sensitive Gloeophyllum trabeum. Untreated southern pine (Pinus spp.) and ammoniacal copper citrate treated southern pine at three concentrations (0.6%, 1.2%, and 2.4%) were used in a 4-week-long standard decay test. Results showed G. trabeum was unable to decay copper-treated wood while both F. radiculosa isolates successfully decayed southern pine at all copper concentrations. G. trabeum and F. radiculosa L-9414-SP showed no detectable FIBRA_00129 expression over the course of this study. F. radiculosa FP-90848-T showed greater FIBRA_00129 downregulation on copper-treated wood than on untreated wood (P = 0.003). Additionally, there was greater FIBRA_00129 downregulation in F. radiculosa FP-90848-T at week 3 compared with other weeks (P = 0.015). Future studies are needed to further evaluate FIBRA_00129 during the decay process to determine its potential role in copper-tolerance.

Дослідження антимікробної дії розчину міді і цитрату срібла за ентеробактеріозів бджіл

Дослідження антимікробної дії розчину міді і цитрату срібла за ентеробактеріозів бджіл

Sensitivity of bees’ pathogenic bacteria to a sample of copper solution and silver citrate

The article presents the studies’ results of the experimental disinfectan’s antimicrobial effect on microorganisms of various morphological groups that currently cause bees’ enterobacteriosis. For work, we used cultures of bee enterobacteria: a pure microorganisms culture of the species Klebsiella pneumoniae and natural (mixed) strains of enterobacteria excreted from sick bee colonies at apiaries in the North-Western region of Ukraine. Sick bees’ families had similar clinical signs – the abdomen in sick bees was thickened, filled with fecal matter, the bees moved slowly, noted damage to the pupae among the sealed brood in the spring and summer, and the families took off in August-September. A solution of copper and silver citrate was used in the native state and in such concentrations – 1:2, 1:5, 1:10, diluted in sterile 0.9 % NaCl. The studies were conducted by the disk-diffuse method. The most active influence of a copper and silver citrate solution sample was recorded with native use on both studied cultures, and the enlightenment zone in the mixed culture was significantly greater (by 28.8 %) than in the pure culture of the species Klebsiella pneumoniae. A significant difference was noted between the two cultures of microorganisms (pure and mixed) with similar dilutions (1:2 and 1:10). Due to the presence of genes encoding adhesins, they determine the formation of a biofilm on the surface of the medium during cultivation of the studied microorganisms, we have a pronounced bacteriostatic effect of the native sample. Such changes are explained by the antimicrobial action of AgNPs associated with the mechanisms of AgNPs adhesion to the surface of the cell wall and membrane, penetration of AgNPs into the cell and damage to intracellular structures (mitochondria, vacuole, ribosomes) and biomolecules (proteins, lipids and DNA), induction of cellular toxicity and oxidative stress AgNPs caused by the generation of reactive oxygen species (ROS) and free radicals and modulation of the signal transduction pathways, which is part of the experimental sample. Silver nanoparticles, unlike copper, can be easily synthesized using physical, chemical, electrochemical and biological methods. Therefore, there is a growing demand for the development of effective and environmentally friendly disinfectants in beekeeping. Further research will be aimed at evaluation a toxic dose of LD50 AgNPs in bee gardens, followed by studying the effect of certain doses in hives in vivo, probably not only as an organic disinfectant, but also as an immunomodulator that stimulates the bee’s body, helps to suppress the development of pathogenic microorganisms in the hive.

A novel strategy to prepare N, S-codoped porous carbons derived from barley with high surface area for supercapacitors

In this work, barley derived N, S-codoped porous carbons are synthesized through a simple, one-step chemical activation method using copper citrate as an activating agent. The copyrolysis of barley and copper citrate contributes to the formation of numerous micro-/mesopores and high surface area. Owing to redox reactions between copper citrate and carbon matrix during the activation process, the as-prepared porous carbon possesses a ultrahigh specific surface area of 2139.6 m2 g−1, hierarchical porous architecture with a large pore volume of 1.16 cm3 g−1, and high nitrogen, oxygen and sulfur contents. The resultant carbon material with high porosity and appropriate heteroatom doping exhibits a high specific capacitance of 401.6F g−1 at 0.5 A g−1 in a 6.0 M KOH electrolyte and good rate capability with the capacitance remaining 165.6F g−1 at 100 A g−1. Additionally, the assembled symmetric carbon-based supercapacitor delivers a high energy density of 30.9 Wh kg−1 and superior long-term cycling stability of 94.8% capacitance retention after 20,000 cycles in 1.0 M Na2SO4 electrolyte. This work provides a facile strategy to design high-surface-area porous carbons with adjustable pore structure and rich heteroatom amount, which holds a promising future for constructing high energy carbon-based supercapacitors.