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1.
Chemosphere ; 261: 128123, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33113646

RESUMO

A pot experiment was carried out to evaluate the efficiency of six types of non-stabilised and Na-carboxymethylcellulose (CMC)-stabilised iron oxide nanoparticles (α-FeOOH, α-Fe2O3, and Fe3O4) on the immobilisation of cobalt (Co) in a soil spiked with different concentrations of it (5, 25, 65, 125, 185 mg kg-1). Amendments were added to soil samples at the rate of 0.5%, and the samples incubated for 60-days. The addition of amendments significantly decreased the concentrations of DTPA-Co and MgCl2-Co, compared with the unamended control. The highest decrease in concentration of DTPA-Co and MgCl2-Co was obtained by the application of CMC-stabilised Fe3O4 (MC) when the concentration of soil total Co was low (5 and 25 mg kg-1) and by the use of CMC-stabilised α-FeOOH (GC) when the concentration of soil total Co was high (65, 125, and 185 mg kg-1), as compared to the control. CMC-stabilised iron oxide nanoparticles were more effective than non-stabilised nanoparticles in the immobilisation of Co. To investigate the effectiveness of iron oxide amendments on the chemical species of Co in the soil spiked with 65 mg kg-1 of this metal, sequential extraction was performed. The concentration of EXCH (exchangeable) and CARB (carbonate) bound fractions decreased significantly after treatment by different amendments. In particular, GC reduced the concentration of EXCH and CARB bound fractions by 20.87, and 17.52%, respectively, compared with the control. Also amendments significantly increased the concentration of FeMn-OX (Fe-Mn oxides), and OM (organic matter) bound, and RES (residual) fractions.


Assuntos
Carboximetilcelulose Sódica/química , Cobalto/análise , Recuperação e Remediação Ambiental/métodos , Compostos Férricos/química , Nanopartículas/química , Poluentes do Solo/análise , Solo/química
2.
Wei Sheng Yan Jiu ; 49(5): 763-768, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070821

RESUMO

OBJECTIVE: To investigate the internal exposure levels of manganese(Mn), cobalt(Co), selenium(Se) and molybdenum(Mo) in blood and urine among the general population in parts of Shaanxi Province, and thereby to analyze their population distribution characteristics. METHODS: In 2017, a total of 720 subjects of general people aged 3-79 years were recruited from 5 counties in Shaanxi Province, by stratified random sampling method, blood and urine samples were collected, and the contents of Mn, Co, Se and Mo in blood and urine samples were detected by inductively coupled plasma mass spectrometry(ICP-MS). The test result were statistically analyzed according to different genders, regions and age groups. RESULTS: Among general people in Shaanxi Province, the median of Mn in blood and urine were separately 8. 43 and 0. 60 µg/L. The median of Mn in blood among males and females were 7. 99 and 8. 81 µg/L, the difference was statistically significant(P<0. 05), the difference of blood Mn between urban and rural areas was statistically significant(P<0. 05). The median of Co in blood and urine were separately 0. 13 and 0. 17 µg/L, the median of Co in blood among males and females were 0. 12 and 0. 15 µg/L, the median of Co in urine among males and females were 0. 16 and 0. 20 µg/L, the differences were statistically significant(P<0. 05), the differences of blood Co and urine Co in urban and rural areas were statistically significant(P<0. 05). The median of Se concentration in blood and urine were separately 73. 20 and 13. 30 µg/L, the median of Se in urine among males and females were 14. 40 and 12. 40 µg/L, the difference were statistically significant(P<0. 05), the differences of blood Se and urine Se in urban and rural areas were statistically significant(P<0. 05). The median of Mo concentration in blood and urine were separately 0. 60 and 50. 40 µg/L, the median of Mo in urine among males and females were 56. 60 and 43. 00 µg/L, the difference was statistically significant(P<0. 05), the difference of blood Mo between urban and rural areas was statistically significant(P<0. 05). Within the same gender, all indexes in whole blood(except female blood Se) were statistically significant among age groups(P<0. 05). The differences of male urine Co, urine Se, urine Mo and female urine Co among age groups were statistically significant(P<0. 05). CONCLUSION: Among general population in Shaanxi Province, the Mn, Co, Se and Mo levels in blood and urine are varied by gender age and area, the blood Se level is relatively low.


Assuntos
Manganês , Selênio , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Cobalto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Molibdênio , Adulto Jovem
3.
Water Sci Technol ; 82(5): 829-842, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33031063

RESUMO

A high-surface-area and inexpensive activated carbon has been produced from lemon peel using chemical activation with H3PO4 at 500 °C in a N2 atmosphere. Afterwards, the synthesized cobalt nanoparticles using coprecipitation method were adsorbed on the activated carbon surface, and as a result magnetic activated carbon was obtained. Sample characterization has been assessed via X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption and magnetic properties. It was found that magnetic activated carbon-cobalt nanoparticles (MAC/Co) synthesized had a high saturation magnetization. The MAC/Co revealed super-paramagnetic behaviors at room temperature, and have been readily isolated from solution by using an exterior magnet. Next, adsorption behavior of malachite green and Pb(II) onto the generated MAC/Co has been examined. Sorption kinetics and equilibrium have been studied using batch procedure. The kinetic and isothermal adsorption results were matched completely with the Elovich and Langmuir models, respectively. Based on the Langmuir model, the highest adsorption capacities of malachite green dye and Pb(II) ion respectively were 263.2 and 312.5 mg g-1 at room temperature. Based on the results, the MAC/Co is a probable economic and effective adsorbent that can be employed as a new adsorbent to remove malachite green dye and Pb(II) from wastewater.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Carvão Vegetal , Cobalto , Chumbo , Fenômenos Magnéticos , Corantes de Rosanilina , Águas Residuárias , Poluentes Químicos da Água/análise
4.
Int J Nanomedicine ; 15: 5613-5627, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32884257

RESUMO

Background: Stimuli-responsive gold nano-assemblies have attracted attention as drug delivery systems in the biomedical field. However, there are challenges achieving targeted delivery and controllable drug release for specific diseases. Materials and Methods: In this study, a glutathione (GSH)-modified fluorescent gold nanoparticle termed AuLA-GSH was prepared and a Co2+-induced self-assembly drug delivery platform termed AuLA-GSH-Co was constructed. Both the pH-responsive character and drug loading behavior of AuLA-GSH-Co were studied in vitro. Kidney-targeting capability was investigated in vitro and in vivo. Finally, the anti-fibrosis efficiency of AuLA-GSH-Co in a mouse model of unilateral ureteral obstruction (UUO) was explored. Results: AuLA-GSH-Co was sensitive to pH changes and released Co2+ in acidic conditions, allowing it to have controllable drug release abilities. AuLA-GSH-Co was found to improve cellular uptake of Co2+ ions compared to CoCl2 in vitro. AuLA-GSH exhibited specific renal targeting and prolonged renal retention time with low non-specific accumulation in vivo. Moreover, the anti-fibrosis efficiency of AuLA-GSH-Co was higher compared to CoCl2 in a mouse model of unilateral ureteral obstruction (UUO). Conclusion: AuLA-GSH-Co could greatly enhance drug delivery efficiency with renal targeting capability and obviously relieve renal fibrosis, providing a promising strategy for renal fibrosis therapy.


Assuntos
Cobalto/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Nefropatias/tratamento farmacológico , Rim/patologia , Nanopartículas Metálicas/química , Animais , Linhagem Celular , Cobalto/química , Modelos Animais de Doenças , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Fibrose , Fluorescência , Glutationa/química , Ouro/química , Concentração de Íons de Hidrogênio , Rim/efeitos dos fármacos , Rim/metabolismo , Nefropatias/patologia , Nanopartículas Metálicas/administração & dosagem , Camundongos Endogâmicos BALB C , Sistema Fagocitário Mononuclear/efeitos dos fármacos , Sistema Fagocitário Mononuclear/metabolismo , Ratos , Obstrução Ureteral
5.
Nat Commun ; 11(1): 4557, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917908

RESUMO

Why metalloenzymes often show dramatic changes in their catalytic activity when subjected to chemically similar but non-native metal substitutions is a long-standing puzzle. Here, we report on the catalytic roles of metal ions in a model metalloenzyme system, human carbonic anhydrase II (CA II). Through a comparative study on the intermediate states of the zinc-bound native CA II and non-native metal-substituted CA IIs, we demonstrate that the characteristic metal ion coordination geometries (tetrahedral for Zn2+, tetrahedral to octahedral conversion for Co2+, octahedral for Ni2+, and trigonal bipyramidal for Cu2+) directly modulate the catalytic efficacy. In addition, we reveal that the metal ions have a long-range (~10 Å) electrostatic effect on restructuring water network in the active site. Our study provides evidence that the metal ions in metalloenzymes have a crucial impact on the catalytic mechanism beyond their primary chemical properties.


Assuntos
Anidrases Carbônicas/química , Íons/química , Metaloproteínas/química , Metais/química , Sítios de Ligação , Anidrase Carbônica II/química , Anidrase Carbônica II/metabolismo , Anidrases Carbônicas/metabolismo , Catálise , Domínio Catalítico , Cobalto/química , Cobre/química , Cristalografia por Raios X , Humanos , Íons/metabolismo , Cinética , Metaloproteínas/metabolismo , Metais/metabolismo , Modelos Moleculares , Níquel/química , Conformação Proteica , Relação Estrutura-Atividade , Especificidade por Substrato , Zinco/química
6.
Chemosphere ; 254: 126869, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957283

RESUMO

This paper presents the results of Co(II) and Ni(II) extraction from model and real solutions using bis(2,4,4-trimethylpentyl)phosphinic acid (i.e. Cyanex 272) that are in agreement with waste-to-resources approach, i.e. the recovery of valuable components from wastes. The results from this study shows that, extraction using Cyanex 272 is an efficient method to recover Co(II) selectively from sulfate electrolytes obtained from the leaching of steel scraps of aircraft engines. The highest selectivity value (∼160) of Co(II) extraction over Ni(II) was obtained at a pH of 4.8, the lowest selectivity value (∼30) was observed at a pH of 5.5, while above this value the selectivity only increased slightly with increasing pH. A pH of 5.2 was selected as a compromise between Co(II) selectivity and Ni(II) amount in the organic phase. The essence of the investigation is to propose important parameters to extract Co(II) from real leach solutions, and to further recover valuable Co(II) from the loaded organic phase by stripping with 1 M H2SO4, thus producing an electrolyte of Co(II) for electrowinning - a possible alternative route for resource recovery. Small volume of the stripping phase (w/o = 1:5) used in this study, lead to an enrichment of sulfate electrolyte in Co(II), resulting in ∼50 g/dm3 of Co(II) in the solution, which is a great advantage of the approach proposed. Such a solution is a valuable source for the electrowinning of metallic cobalt, which can be used for the production of steel alloys, Li-ion batteries or catalysts.


Assuntos
Cobalto/química , Modelos Químicos , Níquel/química , Ácidos Fosfínicos/química , Fontes de Energia Elétrica , Lítio , Sulfatos
7.
Mar Pollut Bull ; 160: 111583, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32861942

RESUMO

We studied the effects of chronic exposure to metals on energy reserves and reproduction in the clam Megapitaria squalida in two nearby populations exposed to different levels of pollution from mining operations in the Gulf of California, Mexico. Female M. squalida from San Lucas beach had good reproductive health status, whereas Santa Rosalia specimens consistently showed low energy reserves, massive oocyte resorption throughout the year, high frequencies of undifferentiated individuals, low proportions of ripe and spawning organisms, smaller and fewer oocytes per follicle, and significantly lower follicular areas. Ovarian levels of Co, Cu, Pb, Mn, and Zn were consistently higher in clams from Santa Rosalia. The poor reproductive health of clams inhabiting this site may be attributed to their long-term exposure to high Co, Cu, and Pb concentrations, as these have been shown to cause toxicity and reproductive impairments in other marine organisms.


Assuntos
Bivalves , Metais Pesados , Poluentes Químicos da Água , Animais , California , Cobalto , Cobre/toxicidade , Monitoramento Ambiental , Feminino , Humanos , Chumbo , Metais Pesados/análise , México , Saúde Reprodutiva , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
8.
J Chromatogr A ; 1629: 461505, 2020 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-32861092

RESUMO

Immobilized metal affinity chromatography (IMAC) is a technique primarily used in research and development laboratories to purify proteins containing engineered histidine tags. Although this type of chromatography is commonly used, it can be problematic as differing combinations of resins and metal chelators can result in highly variable chromatographic performance and product quality results. To generate a robust IMAC purification process, the binding differences of resin and metal chelator combinations were studied by generating breakthrough curves with a poly-histidine tagged bispecific protein. The optimal binding combination was statistically analyzed to determine the impact of chromatographic parameters on the operation. Additionally, equilibrium uptake isotherms were created to further elucidate the impact of chromatographic parameters on the binding of protein. It was found that for protein expressed in CHO cells, Millipore Sigma's Fractogel EMD Chelate (M) charged with Zn2+ and GE's pre-charged Ni Sepharose Excel displayed the highest binding capacities. When the protein was expressed in HEK-293, GE's IMAC Sepharose 6 Fast Flow charged with either Co2+ or Zn2+ bound the greatest amount of protein. The study further identified the metal binding capacity of the resin lot, the protein capacity to which the resin is loaded, and the ratio of poly-histidine tag residues on the protein all impacted the chromatographic performance and product quality. These findings enabled the development of a robust and scalable process. The CHO expressed cell culture product was directly loaded at a high capacity onto variable metal binding affinity Fractogel EMD Chelate (M). A 250 mM imidazole elution condition ensured the product contained monomeric 4 and 6-histidine tagged bispecific proteins. The optimized IMAC process conditions determined in this study can be applied to a wide variety of poly-histidine tagged proteins in research and development laboratories as various poly-histidine tagged proteins of differing molecular weights and formats expressed in either HEK-293 or CHO cells were successfully purified.


Assuntos
Cromatografia de Afinidade/métodos , Histidina/metabolismo , Metais/química , Proteínas Recombinantes/isolamento & purificação , Animais , Células CHO , Quelantes/química , Cromatografia de Fase Reversa , Cobalto/química , Cricetinae , Cricetulus , Células HEK293 , Histidina/genética , Humanos , Proteínas Recombinantes/biossíntese , Zinco/química
9.
PLoS One ; 15(8): e0237100, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760159

RESUMO

PURPOSE: Cobalt exposure is known to cause adverse effects on health. A major use of cobalt is in the manufacture of hard metal. Exposure can lead to asthma, hard metal lung disease, contact allergy and increased risk of cancer. Cobalt is mainly absorbed from the pulmonary tract, however penetration through skin may occur. The relationships between exposure to inhalable cobalt in air and on skin and the uptake in blood and urine will be investigated, as well as the association between dermal symptoms and dermal exposure. METHODS: Cobalt exposure in 71 workers in hard metal production facilities was measured as inhalable cobalt in the breathing zone and cobalt found on skin with acid wash. Uptake of cobalt was determined with concentrations in blood and urine. Correlations between exposure and uptake were analysed. RESULTS: Inhalable cobalt in air and cobalt in blood and urine showed rank correlations with coefficients 0.40 and 0.25. Cobalt on skin and uptake in blood and urine presented correlation coefficients of 0.36 and 0.17. Multiple linear regression of cobalt in air and on skin with cobalt in blood showed regression coefficients with cobalt in blood (ß = 203 p < 0.0010, and ß = 0.010, p = 0.0040) and with cobalt in urine (ß = 5779, p = 0.0010, and ß = 0.10, p = 0.60). CONCLUSIONS: Our data presents statistically significant correlations between exposure to cobalt in air with uptake of cobalt in blood and urine. Cobalt on skin was statistically significant with cobalt in blood but not with urine.


Assuntos
Cobalto/sangue , Intoxicação por Metais Pesados/epidemiologia , Exposição por Inalação/estatística & dados numéricos , Metalurgia/estatística & dados numéricos , Exposição Ocupacional/estatística & dados numéricos , Adulto , Poluentes Ocupacionais do Ar/sangue , Poluentes Ocupacionais do Ar/urina , Cobalto/urina , Feminino , Intoxicação por Metais Pesados/sangue , Intoxicação por Metais Pesados/urina , Humanos , Masculino , Pessoa de Meia-Idade , Pele/metabolismo , Suécia
10.
Environ Health Prev Med ; 25(1): 38, 2020 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-32770943

RESUMO

BACKGROUND: Many studies have investigated heavy metal exposure could increase the occurrence of congenital heart defects (CHDs). However, there are limited data regarding the relationship between cobalt exposure and CHD occurrence in offspring. The aim of this study was to analyze the association between cobalt exposure in mothers and the risk of CHDs in offspring. MATERIALS AND METHODS: In order to explore the association between cobalt exposure and occurrence of congenital heart defect (CHD), a case-control study with 490 controls and 399 cases with CHDs in China were developed. The concentrations of cobalt in hair of pregnant woman and fetal placental tissue were measured and processed by a logistic regression analysis to explore the relationship between cobalt exposure and risk of CHDs. RESULTS: The median concentration of hair cobalt in the control and case group was 0.023 ng/mg and 0.033 ng/mg (aOR, 1.837; 95% CI, 1.468-2.299; P < 0.001), respectively. And the median (5-95% range) fetal placental cobalt concentrations were 19.350 ng/g and 42.500 ng/g (aOR, 2.924; 95% CI, 2.211-3.868; P < 0.001) in the control and case groups, respectively. Significant differences in the middle level of cobalt in hair were found in the different CHD subtypes, including septal defects, conotruncal defects, right ventricular outflow tract obstruction, and left ventricular outflow tract obstruction (P < 0.001). Dramatically, different cobalt concentrations in fetal placental tissue were found in all subtypes of cases with CHDs (P < 0.01). CONCLUSIONS: The finding suggested that the occurrence of CHDs may be associated with cobalt exposure.


Assuntos
Cobalto/efeitos adversos , Cabelo/química , Cardiopatias Congênitas/induzido quimicamente , Exposição Materna/efeitos adversos , Placenta/química , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Adolescente , Adulto , Estudos de Casos e Controles , China , Feminino , Humanos , Gravidez , Fatores de Risco , Adulto Jovem
11.
J Chromatogr A ; 1626: 461358, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797837

RESUMO

In this study, the in-situ conversion of the synthesized Co-Al layered double hydroxide (Co-Al LDH) nanosheets to three dimensional hierarchical zeolitic imidazolate framework-67 (3D HZIF-67) was presented as a cost-effective, highly efficient, flexible and robust sorbent to carry out the microextraction process. In the first stage, the anodized aluminum foil was prepared electrochemically. Then, the Co-Al LDH precursor was constructed on the surface of the previously-prepared anodized Al foil applying in-situ formation approach. The procedure is followed by the conversion of the prepared Co-Al LDH film to 3D HZIF-67 film via a facile solvothermal method without adding cobalt salt. The in-situ prepared 3D HZIF-67-anodized Al was used for the thin film microextraction (TFME) of caffeine. The effective factors in TFME procedure were investigated and optimized through applying Central Composite Design (CCD). In the obtained optimal condition, the calibration curves for TFME-HPLC-UV of caffeine were linear in the range of 1-200 µg L-1 with the coefficient of determination (r2) higher than 0.9915. The limits of detection were 0.33 and 0.38 µg L-1, in water and urine matrices, respectively. Moreover, the enrichment factors (EFs) and absolute recoveries (%AR) were also calculated as 173-198 and 57.1%-65.3%, respectively. The inter-day relative standard deviations (RSDs) were evaluated as the method precision for 20 and 200 µg L-1 of spiked sample and were between 4.9-6.1%. The repeatability of the preparation step was investigated as batch-to-batch reproducibility and it was found to be 4.9%; as a result, the reproducibility of the presented film was approved. Finally, the proposed method was utilized to determine caffeine (as the model analyte) from different types of real samples including urine, coffee, beverage (Pepsi) and shampoo. The obtained recoveries (higher than 88%) confirmed the capability of the method for real sample analysis.


Assuntos
Alumínio/química , Cafeína/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Cobalto/química , Hidróxidos/química , Imidazóis/química , Raios Ultravioleta , Zeolitas/química , Adsorção , Eletrodos , Limite de Detecção , Microscopia de Força Atômica , Porosidade , Reprodutibilidade dos Testes , Solventes/química , Propriedades de Superfície
12.
Chem Biol Interact ; 329: 109217, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32750324

RESUMO

Developing brain is very sensitive to the influence of environmental factors during gestation and the neonatal period. The aim of the study is to assess cobalt and iron accumulation in the brain as well as changes in the expression of iron-regulatory proteins transferrin receptor 1, hepcidin, and ferroportin in suckling mice. Perinatal exposure to cobalt chloride increased significantly cobalt content in brain tissue homogenates of 18-day-old (d18) and 25-day-old (d25) mice inducing alterations in brain iron homeostasis. Higher degree of transferrin receptor 1 expression was demonstrated in cobalt chloride-exposed mice with no substantial changes between d18 and d25 mice. A weak ferroportin expression was found in 18-day-old control and cobalt-treated mouse brain. Cobalt exposure of d25 mice resulted in increased ferroportin expression in brain compared to the untreated age-matched control group. Hepcidin level in cobalt-exposed groups was decreased in d18 mice and slightly increased in d25 mice. The obtained data contribute for the better understanding of metal toxicity impact on iron homeostasis in the developing brain with further possible implications in neurodegeneration.


Assuntos
Encéfalo/metabolismo , Cobalto/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Proteínas Reguladoras do Ferro/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Cobalto/metabolismo , Feminino , Hepcidinas/genética , Hepcidinas/metabolismo , Ferro/metabolismo , Proteínas Reguladoras do Ferro/genética , Camundongos , Camundongos Endogâmicos ICR , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo
13.
Water Sci Technol ; 81(11): 2410-2421, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32784284

RESUMO

The objective of this study is to model the breakthrough adsorption curves of Co (II) ions using spent tealeaves in fixed-bed column experiments. Spent leaves of green tea (GT), peppermint tea (PM) and chamomile (CM) were packed in glass columns with a diameter of 2 cm and height of 15 cm, and used as filters for the removal of the pollutant. Aqueous solutions of cobalt (II) ions (100 mg/L) at pH 6 were prepared and pumped against gravity through the columns at a uniform flow rate of 5 mL/min. Breakthrough curves were fitted for the residual concentration data using the Thomas, Yoon-Nelson, and Clark models, with added empirical terms to delineate the lower tail of the breakthrough curve. These mathematical models were successfully linearized using the natural logarithm for parameter estimation. The results reveal that the Co (II) adsorption fits all three models for all the adsorbents. The Thomas model indicated that the calculated adsorption capacities followed the trend: PM > GT > CM with values of 59.7, 25.2, and 24.9 mg/g respectively. Moreover, CM showed the highest adsorption rates with all the mathematical models, whereas Yoon-Nelson theory provided evidence that PM has the longest 50% adsorption breakthrough among the adsorbents. Lastly, morphological and textural studies indicate that all spent leaves are good candidates as adsorbents due to their high surface heterogeneity. This study proposes the use of spent tealeaves as Co (II) adsorbents because they are inexpensive and environmentally beneficial.


Assuntos
Poluentes Químicos da Água/análise , Purificação da Água , Adsorção , Cobalto , Íons
14.
Environ Pollut ; 266(Pt 2): 115326, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32827984

RESUMO

Excessive exposure to cobalt (Co) is known to make adverse impact on the nervous system, but its detailed mechanisms of neurotoxicity have yet to be determined. In this study, C57BL/6 mice (0, 4, 8, 16 mg/kg CoCl2, 30 days) and human neuroblastoma H4 cells (0, 100, 400, 600 µM CoCl2) were used as in vivo and in vitro models. Our results revealed that CoCl2 intraperitoneal injection caused significant impairments in learning and memory, as well as pathological damage in the nervous system. We further certificated the alteration of m6A methylation induced by CoCl2 exposure. Our findings demonstrate for the first time, significant differences in the degree of m6A modification, the biological function of m6A-modified transcripts between cortex and H4 cell samples. Specifically, MeRIP-seq and RNA-seq elucidate that CoCl2 exposure results in differentially m6A-modified and expressed genes, which were enriched in pathways involving synaptic transmission, and central nervous system (CNS) development. Mechanistic analyses revealed that CoCl2 remarkably changed m6A modification level by affecting the expression of m6A methyltransferase and demethylase, and decreasing the activity of demethylase. We observed variation of m6A modification in neurodegenerative disease-associated genes upon CoCl2 exposure and identified regulatory strategy between m6A and potential targets mRNA. Our novel findings provide novel insight into the functional roles of m6A modification in neurodegenerative damage caused by environmental neurotoxicants and identify Co-mediated specific RNA regulatory strategy for broadening the epigenetic regulatory mechanism of RNA induced by heavy metals.


Assuntos
Cobalto , Neuroblastoma , Doenças Neurodegenerativas , RNA , Adenosina/análogos & derivados , Animais , Cobalto/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Aprendizagem , Memória , Camundongos , Camundongos Endogâmicos C57BL , RNA/efeitos dos fármacos
16.
Medicine (Baltimore) ; 99(27): e20840, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32629669

RESUMO

Osteoporosis is reported to be common among Saudi women. Several minerals appear to be important determinants of insulin-like growth factor (IGF), the bioactivity of which regulates bone and mineral metabolism. Here we proposed that mineral status may alter the IGF system among individuals with osteoporosis. This study aims to evaluate the relationships between essential elements and IGF levels among postmenopausal Saudi women with osteoporosis. A total of 128 postmenopausal Saudi women aged ≥50 years old were recruited in this study. Diagnosis of osteoporosis was done by using dual-energy x-ray absorptiometry to determine the bone minerals density (BMD). Serum calcium and phosphate were determined using routine chemical analyzer. Serum Co, Mn, Ni, Cd were measured using inductively coupled plasma mass spectrometry. Serum IGF-1 and IGF-2 were determined using Luminex xMAP. Using stepwise linear regression analysis, only Cd was identified to be significantly associated with IGF1 in osteoporosis, explaining 3% (confidence interval 0.01-0.05; P = 0001) of the variance perceived. Our results suggest that Cd exposure indirectly affects BMD which may increase the risk of osteoporosis in postmenopausal women. Further longitudinal study using a larger sample size is recommended to determine causality of Cd levels and IGF-1.


Assuntos
Fator de Crescimento Insulin-Like II/análise , Fator de Crescimento Insulin-Like I/análise , Minerais/sangue , Osteoporose Pós-Menopausa/sangue , Absorciometria de Fóton , Idoso , Pesos e Medidas Corporais , Densidade Óssea , Cádmio/sangue , Cálcio/sangue , Cobalto/sangue , Estudos Transversais , Feminino , Humanos , Manganês/sangue , Pessoa de Meia-Idade , Níquel/sangue , Fosfatos/sangue , Arábia Saudita
17.
PLoS One ; 15(7): e0235508, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614917

RESUMO

This study examined the influence of bioaugmentation on metal concentrations (aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel and zinc) in anaerobically digested sewage sludge. To improve the digestion efficiency, bioaugmentation with a mixture of wild-living Archaea and Bacteria (MAB) from Yellowstone National Park, USA, was used. The total concentration of all metals was higher in the digestate than in the feedstock. During anaerobic digestion, the percent increase in the concentration of most of metals was slightly higher in the bioaugmented runs than in the un-augmented runs, but these differences were not statistically significant. However, the percent increase in cadmium and cobalt concentration was significantly higher in the bioaugmented runs than in the un-augmented runs. At MAB doses of 9 and 13% v/v, cadmium concentration in the digestate was 211 and 308% higher than in the feedstock, respectively, and cobalt concentration was 138 and 165%, respectively. Bioaugmentation increased over 4 times the percentage of Pseudomonas sp. in the biomass that are able to efficiently accumulate metals by both extracellular adsorption and intracellular uptake. Biogas production was not affected by the increased metal concentrations. In conclusion, bioaugmentation increased the concentration of metals in dry sludge, which means that it could potentially have negative effects on the environment.


Assuntos
Metais/metabolismo , Esgotos/química , Adsorção , Anaerobiose , Archaea/genética , Archaea/crescimento & desenvolvimento , Archaea/metabolismo , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Biomassa , Cádmio/análise , Cádmio/metabolismo , Cobalto/análise , Cobalto/metabolismo , Metais/química , Pseudomonas/genética , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/metabolismo , Esgotos/microbiologia , Eliminação de Resíduos Líquidos
18.
Acta Crystallogr C Struct Chem ; 76(Pt 7): 663-672, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32624513

RESUMO

The reactivity of the cobalt(III) complexes dichlorido[tris(2-aminoethyl)amine]cobalt(III) chloride, [CoCl2(tren)]Cl, and dichlorido(triethylenetetramine)cobalt(III) chloride, [CoCl2(trien)]Cl, towards different amino acids (L-proline, L-asparagine, L-histidine and L-aspartic acid) was explored in detail. This study presents the crystal structures of three amino acidate cobalt(III) complexes, namely, (L-prolinato-κ2N,O)[tris(2-aminoethyl)amine-κ4N,N',N'',N''']cobalt(III) diiodide monohydrate, [Co(C5H8NO2)(C6H18N4)]I2·H2O, I, (L-asparaginato-κ2N,O)[tris(2-aminoethyl)amine-κ4N,N',N'',N''']cobalt(III) chloride perchlorate, [Co(C4H7N2O3)(C6H18N4)](Cl)(ClO4), II, and (L-prolinato-κ2N,O)(triethylenetetramine-κ4N,N',N'',N''')cobalt(III) chloride perchlorate, [Co(C4H7N2O3)(C6H18N4)](Cl)(ClO4), V. The syntheses of the complexes were followed by characterization using UV-Vis spectroscopy of the reaction mixtures and the initial rates of reaction were obtained by calculating the slopes of absorbance versus time plots. The initial rates suggest a stronger reactivity and hence greater affinity of the cobalt(III) complexes towards basic amino acids. The biocompatibility of the complexes was also assessed by evaluating the cytotoxicity of the complexes on cultured normal human fibroblast cells (WS1) in vitro. The compounds were found to be nontoxic after 24 h of incubation at concentrations up to 25 mM.


Assuntos
Cobalto/química , Complexos de Coordenação/química , Histidina/química , Aminoácidos/química , Cristalografia por Raios X , Ligantes , Percloratos/química
19.
Bone Joint J ; 102-B(7): 832-837, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32600130

RESUMO

AIMS: We have previously demonstrated raised cobalt and chromium levels in patients with larger diameter femoral heads, following metal-on-polyethylene uncemented total hip arthroplasty. Further data have been collected, to see whether these associations have altered with time and to determine the long-term implications for these patients and our practice. METHODS: Patients from our previous study who underwent Trident-Accolade primary total hip arthroplasties using a metal-on-polyethylene bearing in 2009 were reviewed. Patients were invited to have their cobalt and chromium levels retested, and were provided an Oxford Hip Score. Serum ion levels were then compared between groups (28 mm, 36 mm, and 40 mm heads) and over time. RESULTS: Metal ion levels were repeated in 33 patients. When comparing the results of serum metal ion levels over time, regardless of head size, there was a significant increase in both cobalt and chromium levels (p < 0.001). Two patients with larger head sizes had undergone revision arthroplasty with evidence of trunnion damage at surgery. Two patients within the 40 mm subgroup had metal ion levels above the MHRA (Medicines and Healthcare Products Regulatory Agency) threshold for detailed investigation. The increase in cobalt and chromium, when comparing the 36 mm and 40 mm groups with those of the 28 mm group, was not significant (36 mm vs 28 mm; p = 0.092/p = 0.191; 40 mm vs 28 mm; p = 0.200/p = 0.091, respectively). There was no difference, between femoral head sizes, when comparing outcome as measured by the Oxford Hip Score. CONCLUSION: This study shows an increase in cobalt and chromium levels over time for all modular femoral head sizes in patients with metal-on-polyethylene bearings, with two patients demonstrating ion levels above the MHRA threshold for failure, and a further two patients requiring revision surgery. These results may have clinical implications regarding longer term follow-up of patients and future implant choice, particularly among younger patients. Cite this article: Bone Joint J 2020;102-B(7):832-837.


Assuntos
Artroplastia de Quadril/métodos , Cromo/sangue , Cobalto/sangue , Prótese de Quadril , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/instrumentação , Feminino , Humanos , Íons , Masculino , Pessoa de Meia-Idade , Polietileno , Desenho de Prótese
20.
Int J Prosthodont ; 33(4): 386-392, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32639698

RESUMO

PURPOSE: To investigate differences in the performance of polyether ether ketone (PEEK) frameworks vs traditional metal frameworks for removable partial dentures (RPDs) in terms of OHRQoL, patient preference, periodontal indices, and denture satistfaction. MATERIALS AND METHODS: Twenty-six participants were recruited to a randomized controlled crossover trial and were provided with either PEEK or cobalt-chromium (Co-Cr) RPDs. After 4 weeks, the participants were provided with the other RPD. After both 4-week testing periods, the participants chose their preferred RPD and were followed up again at 6 months and 1 year. The primary outcome measure was effect on OHIP-20 score, which was compared among patients using repeated measures ANOVA. Secondary outcomes were participant preference compared using chi-square analysis; Plaque Index and Gingival Bleeding Index (PI and GBI, respectively) compared using repeated measures ANOVA; and McGill Denture Satisfaction Questionnaire (MDSQ) score compared between the two 4-week follow-ups using paired-samples t test. RESULTS: Both Co-Cr and PEEK frameworks resulted in a significant improvement in OHIP-20 score (P < .001), but the material was not a significant factor in changes over 1 year (P = .87). There were no statistically significant differences in participant preference at 1 year (P = .491), nor between RPD materials in their effect on GBI (P = .476), PI (P = .967), or MDSQ (P = .368). CONCLUSION: Both Co-Cr and PEEK RPDs improved OHRQoL to a degree greater than the minimum clinically important difference at 4 weeks, 6 months, and 1 year compared to baseline. No significant preference or improved denture satisfaction score was seen for either material. PEEK frameworks seem to be associated with similar degrees of periodontal effects as Co-Cr frameworks.


Assuntos
Cromo , Cobalto , Prótese Parcial Removível , Estudos Cross-Over , Éter , Humanos , Cetonas , Projetos Piloto
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