Doses Of Cobalt Research Articles

Evaluation of multi-heavy metal tolerance traits of soil-borne fungi for simultaneous removal of hazardous metals.

The demand for environment-friendly cleanup techniques has arisen due to an increase in environmental pollutants. Fungi is the most prevalent and effective class of heavy metal-resistant microorganisms with the ability to leach metals. The objective of the present study was to isolate the fungi from the agricultural soil of Kashmir valley, investigate their multi-metal tolerance to heavy metals and evaluate the metal uptake capacities of the resistant fungi. The fungi were isolated and identified on the basis of morphological and molecular approach (ITS1 and ITS4). The tolerance limits of the isolated fungal strains to various doses of lead (Pb), cadmium (Cd), zinc (Zn), chromium (Cr), copper (Cu), nickel (Ni), and cobalt (Co) was evaluated. Five fungal strains, Aspergillus niger, Fusarium oxysporum, Fusarium verticillioides, Aspergillus fischeri, Epicoccum mackenziei were isolated from the soil samples. To the best of our knowledge, this is the first report on the study of metal resistance of Aspergillus fischeri and Epicoccum mackenziei. Among the identified fungal species, Aspergillus niger and Fusarium oxysporum were found to be most tolerant with a minimum inhibitory concentration (MIC) of 600 ppm against Cu and Cr respectively. Results indicated removal of considerable amount of heavy metals by some of the fungi. The highest metal uptake of 8.31mg/g was found in Fusarium verticillioides for Zn. Surprisingly, these fungal strains demonstrated resistance to metal concentrations above the levels that are universally acceptable for polluted soils, and hence prove to be appealing contenders for use as bioremediation agents for cleaning up heavy metal-polluted environments.

Synthesis and study of Arginin-containing iron and cobalt chelates

Synthesis conditions have been established and arginin-containing iron and cobalt chelate compounds with general formula: Me(Arg)n(CH3COO)2·mH2O, where Me = Fe, Co; Arg – neutral arginin molecule, n = 1÷3; m = 1÷4 have been synthesized. Synthesized chelates have been studied using a number of physical and chemical methods. In particular, the content has been established via trace element analysis, while individuality has been identified using melting temperature measurement and diffractographic method. According to study of qualitative solubility chelates are well soluble in water, though they are poorly soluble in organic solvents. Using the conductometric method there has been calculated the dissociation constant of chelate compound containing solutions. On the basis of preliminary trial tests conducted with a purpose of biological activity study, there has been expressed an opinion that entry of arginin-containing iron and cobalt chelates into composition of broilers’ combined feed premixes has had a positive impact on poultry live weight gain and poultry survival rate. An opinion on the reasonability of basic tests conduction has been given in order to determine the doses of arginin-containing iron and cobalt chelate compounds optimal for broilers.

Influence of microbial culture in combination with micronutrient in improving the groundnut productivity under alluvial soil of India

A field experiment was carried out to study the effect of cobalt, Rhizobium and phosphobacterium inoculations on growth, yield and nutrient uptake of summer groundnut in an alluvial soil at three levels of cobalt viz., zero, 0.21 kg and 0.42 kg ha-1 with four levels of inoculations viz., uninoculation, inoculation with Rhizobium, inoculation with phosphobacterium and inoculation with both Rhizobium and phosphobacterium. Results indicated that combined application of Rhizobium and phosphobacterium inoculation promoted higher dry matter production, pod yield, oil content and nutrient uptake as compared to application of either of the inoculations. Cobalt @ 0.21 kg ha-1 proved to be better to other doses of cobalt. The percent increase in pod yield of different treatment combinations over untreated control varied from, 2.4% with no inoculation + cobalt @ 0.42 kg ha-1 to 35.6% with Rhizobium + phosphobacterium + cobalt @ 0.21 kg ha-1. The uptake of N, P and K by groundnut was significantly higher in the treatments receiving both inoculation and cobalt at 0.21 kg ha-1 than sole application of either inoculation or cobalt.

Effect of different doses of cobalt on rumen digestion in cattle

Optimization of mineral nutrition is a necessary measure to maintain high productivity of beef cattle which often lack minerals in their feed. The innovative base in this case can be ultrafine particles of essential elements characterized by high bioavailability in a small dose. The effect of ultrafine Co3O4 particles on the digestibility of dry matter of feed in the in vitro system (artificial rumen), the amount of volatile fatty acids, nitrogen forms (total, non-protein, ammonia, urea, protein) and on the amino acid composition (arginine, lysine, methionine, alanine, glycine) of animal rumen fluid was studied. The research was conducted in 2023. Cattle of the Kazakh white-headed breed aged 11-12 months with an average weight of 265-275 kg were used as an object of research. It was found that in in vitro studies, dry matter digestibility of feed was 9.0% higher at a concentration of 0.36 g/mL of Co3O4 ultrafine particles. Analysis of volatile fatty acid concentration showed that this dosage increases acetic acid, propionic acid, butyric acid, valerianic acid, and caproic acid. The introduction of ultrafine Co3O4 particles increased the content of protein nitrogen and total nitrogen in the experimental animals, indicating the intensification of rumen microbiocenosis. At introduction of ultrafine Co3O4 particles, shifts in the amino acid composition of the rumen contents were observed, which may be caused by the changes in the nature of nitrogenous substances transformation in the digestive tract. It is concluded that the use of ultrafine Co3O4 particles has a positive effect on the digestive processes in the rumen.

Microbial impact to environmental toxicants Ni(II) and Co(II): Joint toxicity and cellular response in Paramecium

Cobalt (Co) and Nickel (Ni) are increasingly found in our environment. We analysed their combined toxicity and uptake mechanisms in the early food chain by studying bacteria and the bacterivorous ciliate Paramecium as a primary consumer. We exposed both species to these metals to measure the toxicity, uptake and transfer of metals from bacteria to Paramecium. We found that Ni is more toxic than Co, and that toxicity increases for both metals when (i) food bacteria are absent and (ii) both metals are applied in combination. The cellular content in bacteria after exposure shows a concentration dependent bias for either Ni or Co. Comparing single treatment and joint exposure, bacteria show increased levels of both metals when these are both exposed. To imitate the basic level of the food chain, we fed these bacteria to paramecia. The cellular content shows a similar ratio of Nickel and Cobalt as in food bacteria. This is different to the direct application of both metals to paramecia, where Cobalt is enriched over Nickel. This indicates that bacteria can selectively pre-accumulate metals for introduction into the food chain. We also analysed the transcriptomic response of Paramecium to sublethal doses of Nickel and Cobalt to gain insight into their toxicity mechanisms. Gene ontology (GO) analysis indicates common deregulated pathways, such as ammonium transmembrane transport and ubiquitine-associated protein degradation. Many redox-related genes also show deregulation of gene expression, indicating cellular adaptation to increased RONS stress. This suggests that both metals may also target the same cellular pathways and this is consistent with the increased toxicity of both metals when used together. Our data reveal complex ecotoxicological pathways for these metals and highlights the different parameters for their fate in the ecosystem, in the food chain and their ecotoxicological risk after environmental contamination.

Pre- and post-melatonin mitigates the effect of ionizing radiation-induced damage in wheat by modulating the antioxidant machinery

As an indolamine, melatonin (C13H16N2O2) performs essential roles in the regulation of plant growth and development and ameliorates the harmful effects of abiotic stresses. This study examined two types of melatonin application, pre-sowing (prMel) and application during growth (ptMel), in wheat (Triticum aestivum L.) seedlings exposed to four different doses (100, 200, 300, and 400 Gy) of radioactive cobalt (60Co) gamma rays as dry seeds to investigate their ameliorative effects on ionizing radiation (IR) stress. Peroxidase, catalase, superoxide dismutase, ascorbate peroxidase, glutathione reductase, mono- and dihydroxyperoxidase, and phenylalanine ammonia-lyase activities, and levels of lipid peroxidation, H2O2, and total glutathione (GSH), and phenolic acids (PHAs) in soluble free, ester, glycoside and ester-bound forms were examined in the seedlings. Both melatonin applications were found to increase lipid peroxidation, H2O2, and GSH contents previously reduced by gamma irradiation. The IR treatment-induced increases in enzyme activities were significantly reduced by melatonin applications. The study findings indicated that high doses of IR resulted in significant decreases in the activity and levels of the measured traits. The predominant PHAs in the tissues were vanillic, ferulic, and p-coumaric acids. In addition, ptMel application combined with IR stress lowered the total phenolic acid contents in the soluble forms while increasing those in the cell wall-bound form. In conclusion, the antioxidant system in the seedlings exposed to the different gamma ray doses was regulated by prMel and ptMel applications in such a manner as to alleviate IR stress-induced oxidatives damages in the wheat.

The Effect of Some Heavy Metals on the Growth of Garlic under In Vitro Conditions

Garlic (Allium sativum L.) is an important plant species because of its nutritional and medical value. One of the important advantages of plant tissue culture is in vitro selection. The tolerance of garlic to some heavy metals under in vitro conditions was studied. In vitro experiments were carried out in Murashige and Skoog (MS) nutrient medium supplemented with different doses of cadmium (Cd), cobalt (Co), nickel (Ni), aluminum (Al), copper (Cu), chromium (Cr), and lead (Pb) at 100 µm, 200 µm, 300 µm, 400 µm, and 500 µm. During experiments, plant length, number of leaves, leaf length, root number, and root length parameters were considered. In the findings, there was a decrease in both leaf and root development as doses of heavy metals increased. In addition, it has been found that the decrease in plant development at doses of 400 µm and 500 µm was higher compared with other doses. There was no root formation at high doses of Cd, Co, Ni, and Cu (400 µm and 500 µm). As a recommendation, further research should be conducted under in vivo conditions to evaluate the level of tolerance to heavy metals in garlic.

Exogenous melatonin ameliorates ionizing radiation-induced damage by modulating growth, osmotic adjustment and photosynthetic capacity in wheat seedlings

As a multifunctional signal molecule, melatonin (N-acetyl-5-methoxytryptamine) plays many important roles in the regulation of plant growth and development. The effect of melatonin application on enhancing plant stress tolerance has been widely reported, but the ameliorative effect of exogenous melatonin treatment on plants exposed to ionization stress is still unknown. This study investigated the ameliorative effects of two types of melatonin treatment, pre-sowing priming (prMel) and application during growth (ptMel), in wheat (Triticum aestivum L.) seedlings exposed to different radiation doses (100, 200, 300 and 400 Gy) of radioactive cobalt (60Co) gamma rays as dry seeds. The growth parameters, photosynthetic pigments, chlorophyll fluorescence, osmotic potential with soluble sugars, fructans and proline contents were then examined. The results indicated that high doses of ionizing radiation (IR) led to decreases in plant growth, pigment contents, chlorophyll fluorescence ratios and osmotic potential. However, soluble sugar, fructan and proline contents increased under IR stress conditions. Both melatonin applications, but particularly prMel, enhanced the morphological parameters, preserved the photosynthetic machinery and regulated the osmotic adjustment of IR-stressed wheat seedlings. Taken together, the findings show that exogenously applied melatonin, particularly prMel, play a significant role in alleviating IR stress in wheat seedlings.

Effects of gamma irradiation on agromorphological characteristics of chili (Capsicum annuum L.) var. Kulai

The increasing demand for chilli has drawn the interest of chilli breeders to improve the production of this crop. Mutation breeding is applied in many crops improvement programs as it can rapidly create the variability of inherited traits in crops. This study evaluates the effects of irradiation doses of radioactive cobalt (60Co) γ rays on seed performances, morphological characteristics and yield of chilli (Capsicum annum L.) var. Kulai grown under laboratory and glasshouse conditions. The chilli seeds were treated with gamma radiation at 0, 20, 40, 60, 80, 100, 200, 300, 400, 500 and 600 Gy. The effect of gamma-rays was assessed towards germination, survival rate and several morphological characteristics. From the observation, seeds from all treatments were germinated (100%) in 10 days. However, the gamma radiation affects the survival rate, fruit length, fruit weight, plant height, and most of the results were lower upon exposure to higher doses particularly 100 Gy and above. Germination rate, plant height, plant survival rate and other morphological characteristics of the irradiated plant were observed to improve at lower doses (40, 60 and 80 Gy). Apparently, lower gamma-ray doses (<100 Gy) were more suitable to study the effect on seed germination as well as other morphological characters of Capsicum annuum L. especially Kulai variety. Mutagenic dose of 300 Gy was estimated as the LD50 for Kulai variety. The findings of this study provide useful information for mutation breeding in Capsicum annuum L. using gamma radiation for future breeding programmes in chilli.

The economic efficiency of the use of mixed ligand complexes of Zinc, Man-ganese and Cobalt in the rations of highlyproductive cows of the Ukrainian Black-Spotted Dairy breed

The research results on the cost-effectiveness of using different doses of Zinc, Manganese, and Cobalt due to their mixed ligand complexes in the feeding rations of highly productive cows of the Ukrainian Black-Spotted Dairy breed in the first 100 days of lactation are presented. Experimental studies were conducted on five (one control and four experimental) groups of analogous cows in the conditions of the Kyiv region's ALC “Terezyne” Bila Tserkva district. The optimal dose of mixed-ligand complexes of Zinc, Manganese, and Cobalt was established in previous studies, with a concentration of 1 kg of dry matter (DM) of the feed mixture (FM), mg: Zinc – 60.8; Manganese – 60.8, and Cobalt – 0.78. For the second experimental group, the concentration of these trace elements increased by 10 %, and in the 3rd, fourth, and fifth experimental groups – on the contrary, it decreased by 10 %, 20, and 30 %, respectively, compared with the control. The highest hopes of essential fat milk were in experimental cows of the 4th group and were 4791.7 kg, where due to mixed ligand complexes, the doses of Zinc and Manganese were 48.6 mg, and Cobalt – 0.62 mg per 1 kg of DM. The hopes of essential fat milk, compared with the control, in cows of the second experimental group, was higher by 155.2 kg, the 3rd – by 211.3 kg, the 4th – by 427.0 kg, and the fifth experimental group – by 234.6 kg. The lowest hopes of essential fat milk were in cows of the first control group. Using additives of mixed ligand complexes of Zinc, Manganese, and Cobalt in complete feed mixtures allowed profit, UAH: in the first control group – 7581.5; second experimental group – 7963.1; third – 8004.1; fourth – 8437.6 and 5th – 8119.0. The most significant profit, by UAH 856.1, or 11.29 % more than control, was obtained in the fourth experimental group of cows of the Ukrainian Black-Spotted Dairy breed. The positive effect of feeding different levels of Zinc, Manganese, and Cobalt due to their mixed ligand complexes to cows of the Ukrainian Black-Spotted Dairy breed in the first 100 days of lactation on the indicators of economic efficiency of milk production. The best results were obtained in the fourth experimental group, whose cows were fed a feed mixture containing 1 kg of DM, mg: Zinc – 48.6; Manganese – 48.6; Cobalt – 0.62; Selenium – 0.3; Copper – 12 and Iodine – 1.1.

Anticancer Activity of Urease Mimetic Cobalt (III) Complexes on A549-Lung Cancer Cells: Targeting the Acidic Microenvironment.

Tumour cells maintain a local hypoxic and acidic microenvironment which plays a crucial role in cancer progression and drug resistance. Urease is a metallohydrolases that catalyses the hydrolysis of urea into ammonia and carbon dioxide, causing an abrupt increase of pH. This enzymatic activity can be employed to target the acidic tumour microenvironment. In this study, we present the anticancer activities of urease mimetic cobalt (III) complexes on A549 cells. The cells were treated with different doses of cobalt (III) complexes to observe the cytotoxicity. The change in cellular morphology was observed using an inverted microscope. The cell death induced by these complexes was analysed through ATP proliferation, LDH release and caspase 3/7 activity. The effect of extracellular alkalinization by the cobalt (III) complexes on the efficacy of the weakly basic drug, doxorubicin (dox) was also evaluated. This combination therapy of dox with cobalt (III) complexes resulted in enhanced apoptosis in A549 cells, as evidenced by elevated caspase 3/7 activity in treated groups. The study confirms the urease mimicking anticancer activity of cobalt (III) complexes by neutralizing the tumour microenvironment. This study will motivate the applications of transition metal-based enzyme mimics in targeting the tumour microenvironment for effective anticancer treatments.

Carbon monoxide adsorption on cobalt overlayers on a Si(1 1 1) surface studied by STM and XPS

We report on the structure and reactivity of the Co-Si polycrystalline surfaces that form at room temperature (RT). Scanning tunneling microscopy (STM) was used to examine the surface morphology while X-ray photoelectron spectroscopy (XPS) was used to detect the chemical states of cobalt and silicon as a function of cobalt coverage. Moreover, XPS measurements after exposing the Co-Si(111) samples to CO gas provide information about CO adsorption and dissociation. When <5 ML Co is deposited on Si(111) at RT, most Co atoms diffuse into Si lattice and no CO adsorption is found at RT. This shows that coordination of Co to Si suppresses CO adsorption. Neither Co-induced Si(111)-ring cluster nor CoSi2 crystalline film adsorb CO at RT. In contrast, CO adsorption was found at RT for cobalt doses >5 ML, an indication that Co-rich silicides and metallic Co present. The CO adsorption capacity increases with cobalt dose up to 30 ML after which it levels off, an indication that metallic cobalt sites are dominantly exposed on the surface. Furthermore, a closed metal film is formed for 200 ML dose. Some dissociation of CO was observed during heating of the CO-covered samples for Co doses ≥30 ML.

Macroelement content in plants after amendment application to cobalt-contaminated soil

AimThe study was undertaken to determine the effect of amendments used in remediation of cobalt-contaminated soil on the macroelement content of all organs of spring barley (the main crop) and white mustard (the after-crop).MethodsIn the experiment, six blocks were selected: without amendments; with manure (bovine, granulated); clay; charcoal; zeolite; and with calcium oxide (50%). In each of the blocks, increasing doses of cobalt were applied: 0, 20, 40, 80, 160, and 320 mg kg−1 of soil.ResultsCobalt-contaminated soil and amendments application had a significant effect on macroelement content of all organs of both plants.ConclusionsIn blocks without amendments, 80 mg Co kg−1 contributed the most increase in nitrogen, sodium, and calcium contents of both organs of spring barley. Cobalt-contaminated soil increased content of all macroelements in white mustard organs. Application of amendments to soil had strong impact on phosphorus, sodium, and calcium contents of organs of both plant species, compared to the control block (without amendments). Among the amendments, manure had the greatest effect on the content of macroelements in plants. Manure increased phosphorus, potassium, and sodium contents of all organs of both plants. The optimal content of macroelements is extremely important for the growth and development of plants, especially on soils contaminated with trace elements, including cobalt.

Використання змішанолігандних комплексів Цинку, Мангану й Кобальту в годівлі високопродуктивних корів у пізній сухостійний період

The results of establishing the optimal feeding doses of Zinc, Manganese, and Cobalt in the form of their mixed-ligand complexes for high-yielding cows of Holstein, Ukrainian Red-Spotted and Ukrainian Black-Spotted dairy breeds during the late dry period were presented, their influence on the future productivity and reproductive qualities of cows were also determined. It was found that lower doses of mixed-ligand complexes of Zinc, Manganese, and Cobalt in the feed mixture stimulated its consumption better. The cows of the 4th experimental group consumed more of the feed mixture, where the concentration of Zinc and Manganese was 35 mg, and Cobalt – 0.49 mg per 1 kg of DM. At various doses of mixed-ligand complexes of Zinc, Manganese, and Cobalt, the increase in live weight in cows of the control group was 24.3 kg, and in the experimental groups, it ranged from 23.7 kg to 26.9 kg, which is 8.6% and 10.7% (P &lt; 0,05) more in the 3rd and 4th groups compared with the control. A decrease in the concentration of mixed-ligand complexes of Zinc, Manganese, and Cobalt in the diets of dry cows in the experimental groups by 10, 20, 30 and 40% had a positive effect on their further milk productivity. During the first 100 days of lactation, they milked 60-180 kg of milk more compared to the control with an increase in fat content by 0.01–0.05%. Also, in the milk of experimental group’s cows, compared with the control, the protein content increased (3.22–3.23% versus 3.14%), and the feed costs per 1 kg of milk in them were lower by 3.5–9.4%. Smaller doses of zinc, manganese, and cobalt contributed better to lengthening the period of prolonged action of their mixed-ligand complexes on the body of lactating cows. The calves’ live weight at the birth in the 4th experimental group exceeded the indicator of their peers from the control group by 2.3 kg or 8.81%, while the calves obtained from cows of the 2nd experimental group prevailed the control by 1.6 kg, or 6, 13 %, from the 3rd experimental group – by 1.8 kg, or 6.90%, and the 4th experimental group – by 1.7 kg, or 6.51%. The duration of the service period in all experimental groups of cows was within the recommended norms and was 87.8 days in the control group, and the 2nd, 3rd, 4th and 5th experimental groups, respectively 84.7 days, 82.2; 80.6 and 83.5 days, respectively, and there was less in control by 3.1–7.1 days or 3.3–8.2%. The insemination index in the cows’ control group was 1.5, and in the experimental one – 1.2–1.4, which is 6.7–20.0% less.

Irradiação ionizante em pós-colheita de atemoia cultivar ‘Thompson’

The study of ionizing irradiation with Cobalt 60 (60Co), in this experiment, aimed to evaluate its influence on postharvest physical parameters for atemoia cv. ‘Thompson’, which are related to the fruit ripening process. The irradiation was carried out at the Radiation Technology Center -CTR IPEN / CNEN -SP, located in the university city USP (University of São Paulo) in the compact multi-purpose radiator where gamma rays are used. Atemias were irradiated with the following doses of cobalt 60 (60Co): T0 = No irradiation (control), T1 = 0.2kGy, T2 = 0.4kGy, T3 = 0.6kGy, T4 = 0.8kGy, T5 = 1,0kGy and T6 = 1,2kGy and then packed in expanded polystyrene trays (2 fruits / tray) and sealed with 0.020mm polyvinyl chloride films; exception made to the control treatment which did not receive irradiation; for each analysis parameter there were three repetitions with two fruits per repetition. The fruits under study were stored in a cold chamber at 15 ± 0.2ºC and 90 ± 2% RH. In all irradiation doses, the following analyzes were carried out: loss of fresh mass, soluble solids (SS), titratable acidity (AT), pH, ascorbic acid (AA), reducing sugars, respiratory rate. The analyzes were analyzed every three days (0,3,6,9,12,15 and 18) days of storage. The experiment was conducted in a completely randomized design (D.I.C.), in a factorial scheme (treatment x storage), composed of seven doses of gamma irradiation and seven storage times. The results were subjected to analysis of variance and the means compared by Tukey's test at the level of 5% probability and regression was performed for the analyzes in the storage period. This experiment can conclude that the doses of 1.0kGy and 1.2kGy demonstrate greater control of breathing, in atemoia, until the 9th day; three days more than the control treatment, the other parameters analyzed did not show any interference in the increase in postharvest life of the atemous cv ‘Thompson’.

Evaluation of cobalt as a performance enhancing drug (PED) in racehorses

Cobalt is a required trace element in animals, but administration in excess is considered dangerous and potentially performance enhancing in equine athletes. This study seeks to determine if cobalt may actually act as a performance enhancing drug (PED) by altering biochemical parameters related to red blood cell production as well as markers of aerobic and anaerobic exercise performance. In addition, for adequate regulation of naturally occurring substances, such as cobalt, its distribution among the population must be defined. In order to identify this distribution, plasma Cobalt was determined from 245 Standardbred horses with no cobalt supplementation from farms in New York and New Jersey, including horses at the Rutgers University Equine Science Center. Samples were analysed by Inductively Coupled Plasma Mass Spectrometry. Seven healthy, race fit Standardbreds (4 geldings, 3 mares, age: 5±3 years, ~500 kg) were used for the PED experiment. An incremental graded exercise test (GXT) to measure maximal aerobic capacity (V̇O2max) and markers of performance, measurement of plasma volume and blood volume as well as the measurement of lactate, erythropoietin (EPO), and various blood haematological factors were determined 7 days prior to cobalt administration. Each horse was administered a sterile solution of cobalt salts (50 mg of elemental Co as CoCl2 in 10 ml of saline, IV) at 9 AM on three consecutive days via the jugular vein. Blood samples were obtained from the contralateral jugular vein before and at 1, 2, 4 and 24 h after administration. Plasma and blood volume were measured one day after the last dose of cobalt, and a post administration GXT was performed the next day. Horses were observed for signs of adverse effects of the cobalt administration (agitation, sweating, increased respiration, etc.). Plasma cobalt concentration increased from a pre-administration mean of 1.6±0.6 to 369±28 μg/l following 3 doses of the cobalt solution (P&lt;0.05). This Co concentration was unaccompanied by changes in aerobic or anaerobic performance, plasma EPO concentration, plasma volume, resting blood volume, total blood volume, or estimated red blood cell volume (P&gt;0.05). There were no observed adverse effects.

Remediation of Cobalt-Contaminated Soil Using Manure, Clay, Charcoal, Zeolite, Calcium Oxide, Main Crop (Hordeum vulgare L.), and After-Crop (Synapis alba L.)

This study was undertaken to determine the effects of various substances on soil contaminated with cobalt (Co) on the mass and content of cobalt in the main crop—spring barley (Hordeum vulgare L.)—and the after-crop—white mustard (Synapis alba L.). Manure, clay, charcoal, zeolite, and calcium oxide were used for phytostabilization. Cobalt was applied in the form of CoCl2 in doses of 0, 20, 40, 80, 160, and 320 mg/kg soil. Amendments in the form of manure, clay, charcoal, and zeolite were applied in an amount of 2% in relation to the weight of the soil in a pot, with calcium oxide at a dose of 1.30 g CaO/kg of soil. The highest cobalt doses resulted in a significant reduction in yield of both plants and in tolerance index for cobalt. Increasing contamination of soil with cobalt resulted in a major and significant increase in its content in plants and a reduction in cobalt translocation factor in both plants. Amendments used in phytostabilization had a significant effect on growth and development of oat and content of cobalt in plants. The strongest effect on the yield of above-ground parts was exerted by manure (both plants) and calcium oxide (white mustard), while the strongest effect on weight of roots was exerted by calcium oxide (both plants) and zeolite (white mustard). The addition of manure, zeolite and calcium oxide to soil caused an increase of the tolerance index for both plants, while the addition of clay only had a positive effect for white mustard. All substances used in phytostabilization (except zeolite) decreased cobalt content of roots, and manure and calcium oxide in above-ground parts of spring barley; manure and zeolite only in above-ground parts, and calcium oxide in both organs of white mustard. Most of them also reduced bioconcentration of cobalt in above-ground parts, calcium oxide decreased cobalt content in roots of both plants, and manure in roots of spring barley. The effect on cobalt translocation was less clear, but most substances used in phytostabilization increased the transfer of cobalt from the soil to plants. White mustard had higher ability to accumulate cobalt than spring barley.

Modulating the cobalt dose range to manipulate multisystem cooperation in bone environment: a strategy to resolve the controversies about cobalt use for orthopedic applications.

The paradoxical effect of cobalt on biological processes has aroused controversy regarding the application of cobalt-based biomaterials in bone regeneration. Tuning the dose range of cobalt ions may be a valid strategy to resolve the controversies about cobalt use for orthopedic applications. Recent progress in bone biology has highlighted the effects of multisystem cooperation (especially of osteoimmune, skeletal, and vascular systems) on bone dynamics. Before the application of this dose-tuning strategy, a deeper understanding of its dose-dependent effect on the cooperation of osteoimmune, skeletal, and vascular systems is needed. However, due to the difficulties with investigating the interaction of multiple systems in vitro, the multimodal effects of cobalt on bone homeostasis were investigated here, in an in vivo scenario.Methods: In vitro CCK8 assay and cytoskeletal staining were preformed to detecte the cell cytotoxic reaction in response to 0.1-100 ppm cobalt stimulation. Blood clot containing 0.1 to 5 ppm of cobalt were implanted in the rat calvarium defect. The gene profile of osteoimmune, skeletal, and vascular system as well as the systemic toxicity were evaluated via RT-qPCR, histological analysis and inductively coupled plasma mass spectrometry. The bone regeneration, osteoclastogenesis and vascularization were assessed by micro-ct and histological analysis.Results: Cobalt concentration below 5 ppm did not cause cell toxicity in vitro. No systemic toxicity was observed in vivo at 0.1-5 ppm cobalt concentration. It was found that the early cytokine profiles of the multiple interacting systems were different in response to different cobalt doses. Most of the anti-inflammatory, osteogenic, and proangiogenic factors were upregulated in the 1 ppm cobalt group at the early stage. In the late stage, the 1ppm group was most superior in bone regenerative effect while the 5 ppm group displayed the strongest osteoclastogenesis activity.Conclusions: The 1 ppm concentration of cobalt yielded the most favorable cooperation of the osteoimmune, skeletal, and vascular systems and subsequently optimal bone regeneration outcomes. Tuning the cobalt dose range to manipulate the cooperation of osteoimmune, skeletal, and vascular systems could be a promising and valuable strategy to prevent paradoxical effects of cobalt while preserving its beneficial effects.

High doses of cobalt inhibited hair follicle development in Rex Rabbits

&lt;p&gt;An experiment was conducted to investigate the effect of cobalt supplementation on hair follicle development in rabbits. Rex rabbits (30-d-old, n=180) were divided randomly into five equal treatment groups: rabbits fed a basal diet (control, measured cobalt content of 0.27 mg/kg) or rabbits fed a basal diet with an additional 0.1, 0.4, 1.6 or 6.4 mg/kg cobalt (in the form of cobalt sulfate) supplementation (measured cobalt contents of 0.35, 0.60, 1.83 and 6.62 mg/kg, respectively). Treatment with 6.4 mg/kg cobalt significantly decreased hair follicle density (&lt;em&gt;P&lt;/em&gt;&amp;lt;0.05), while low levels of cobalt (0.1-1.6 mg/kg) had no effect on hair follicle density (&lt;em&gt;P&lt;/em&gt;&amp;gt;0.05). The addition of dietary cobalt at the highest level examined (6.4 mg/kg) significantly increased the gene expression of bone morphogenetic protein (BMP) 2 and BMP4 in skin tissue (&lt;em&gt;P&lt;/em&gt;&amp;lt;0.05), while the mRNA levels of versican, alkaline phosphatase, hepatocyte growth factor, and noggin remained unchanged (&lt;em&gt;P&lt;/em&gt;&amp;gt;0.05). Compared with their levels in the control group, dietary cobalt treatment significantly suppressed the protein levels of p-mechanistic target of rapamycin (mTOR) and p-ribosomal protein S6 protein kinase (&lt;em&gt;P&lt;/em&gt;&amp;lt;0.05) but did not alter the protein levels of p-AMP-activated protein kinase, Wnt10b or p-β-catenin (&lt;em&gt;P&lt;/em&gt;&amp;gt;0.05). In conclusion, cobalt at the highest concentration examined inhibited hair follicle development, which may have involved the mTOR-BMP signalling pathway.&lt;/p&gt;

269 Attempts to improve equine athletic performance via hypoxia-inducing techniques

Abstract Hypoxic conditions encountered at high altitudes result in potential adaptations such as increased hematocrit, hemoglobin, and muscle mitochondrial function. However, living at high altitudes is not practical for many equine athletes. Unfortunately, many trainers have resorted to administering erythropoietin to stimulate red cell production or a large dose of cobalt which reportedly has a hypoxic-inducing effect. Both practices can result in serious health complications (including death) and are typically banned, with a testing threshold of 25 ppb for serum cobalt. Results from Spartan Equine Research confirmed that oral supplementation with 60X the 2007 NRC recommendation of cobalt resulted in serum concentration of 4.7 ppb – far below the testing threshold. These results suggest injectable cobalt, not dietary, is the source of concern. A means of inducing hypoxic effects in humans without living at altitude involves a “tent” covering a bed in which low oxygen concentrations are maintained while sleeping. Similar low-oxygen stalls have been designed for horses. Recent Spartan Equine Research failed to detect any improvement in racing performance in Thoroughbreds housed in such stalls. Challenges not experienced with human athletes were encountered relating to humidity and gases associated with urination and defecation within the airtight chamber – rendering such stalls of limited practicality and safety.