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BACKGROUND: To evaluate the effectiveness and safety of Xingnaojing combined with naloxone in the treatment of carbon monoxide poisoning. METHODS: By retrieving the literatures published in the databases of PubMed, Cochrane Library, Web of Science, Embase, Wanfang Database, Weipu Database, and China National Knowledge Infrastructure from January 2010 to September 2021, the data of randomized controlled trials (RCTs) of Xingnaojing combined with naloxone in the treatment of carbon monoxide poisoning were extracted. The methodological quality of the included RCTs was evaluated by using the tools of bias risk evaluation of Cochrane Collaboration, and the data were statistically analyzed by using RevMan 5.3 software. RESULTS: A total of 20 literatures were included, involving in 771 cases treated by Xingnaojing combined with naloxone and 761 cases in the control group. The effective rate of the experimental group is higher than that of the control group [risk ratio (RR)â =â 1.20, 95% confidence interval (CI) (1.14, 1.26)]. The average awake time (STD mean differenceâ =â -2.08, 95% CI [-2.60, -1.56]), physical recovery time (STD mean differenceâ =â -2.94, 95% CI [-3.59, -2.28]), delayed encephalopathy (RRâ =â 0.44, 95% CI [0.31, 0.62]), and adverse reactions (RRâ =â 0.23, 95% CI [0.10, 0.54]) was lower than that of the control group. CONCLUSION: Xingnaojing combined with naloxone in the treatment of carbon monoxide poisoning is significantly superior to naloxone, but it still needs to be further verified by high-quality large samples of RCTs.
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Intoxicação por Monóxido de Carbono , Humanos , Intoxicação por Monóxido de Carbono/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Naloxona/uso terapêuticoRESUMO
The remediation of metalliferous mine tailings remains a challenge in many regions of the world. A field experiment was conducted on representative Pb-Zn mine tailings with different species richness (1-, 4-, 8-, and 16-species) to evaluate the potential roles of species diversity in the phytoremediation of metalliferous mine tailings. The main results were â high species diversity greatly enhanced vegetation cover and biomass. For example, the average vegetation cover and biomass were 33.4% and 66.7 g ·m-2 in 1-species plots and reached 78.4% and 183.8 g ·m-2 in 16-species plots, respectively. â¡ Plant species diversity had significant effects on nutrient accumulation. Total organic carbon (TOC), water organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP) significantly increased with the species diversity (TOC:r=0.30,P<0.001; SOC:r=0.20,P<0.05; TN:r=0.24,P<0.05; TP:r=0.20,P<0.05). ⢠Species diversity not only reduced the concentration of diethylenetriamine pentaacetate (DTPA)-extracted metals in the mine tailings, but also decreased heavy metal transfer and accumulation in the soil-plant system. With enhanced species diversity, DTPA-extracted Cd, Cu, Pb, and Zn decreased significantly (DTPA-Cd:r=0.20,P<0.05; DTPA-Cu:r=0.19, P<0.05; DTPA-Pb:r=0.23, P<0.05; DTPA-Zn:r=0.23, P<0.05). With increasing species diversity, a slightly decreasing trend was observed for Cd, Cu, Pb, and Zn concentrations in the aboveground parts of plants (Cd:r=-0.16, P<0.01; Cu:r=-0.23, P<0.001; Pb:r=-0.15, P<0.05; Zn:r=-0.18, P<0.001). In conclusion, plant diversity can play an important role in mine reclamation.
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Metais Pesados , Poluentes do Solo , Chumbo , Metais Pesados/análise , Desenvolvimento Vegetal , Solo , Poluentes do Solo/análise , ZincoRESUMO
PURPOSE: To investigate the effect of human bone marrow mesenchymal stem cells (hBM-MSCs) on invasion of tongue squamous cell carcinoma cell line Cal-27 and its mechanism. METHODS: hBM-MSCs and Cal-27 were cultured respectively, and the morphology of the cells was observed under an inverted microscope. The co-cultured Cal-27 cells were obtained by co-culture of hBM-MSCs and Cal-27. The migration area of Cal-27 was observed by scratch test;transwell migration and invasion experiments were performed to observe migration and invasion of Cal-27, and a bar graph was then drawn. Fluorescence quantitative PCR was used to observe the effect of hBM-MSCs on gene expression of the tumor markers E-cadherin, twist, slug, snail, MMP-2 and MMP-9. Western blot was used to observe the effect of hBM-MSCs on protein expression of MMP-2 and MMP-9, related to the invasion of Cal-27. SPSS 19.0 software package was used for statistical analysis of the data. RESULTS: Under the influence of hBM-MSCs, the invasion of Cal-27 was promoted, accompanied by down-regulation of E-cadherin, up-regulation of twist, slug, snail, MMP-2, MMP-9 and up-regulation of MMP-2 and MMP-9 expression. CONCLUSIONS: hBM-MSCs can promote invasion of Cal-27 cells, which may be related to up-regulation of the expression of tumor markers related to invasion of Cal-27 cells.
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Carcinoma de Células Escamosas , Células-Tronco Mesenquimais , Neoplasias da Língua , Células da Medula Óssea , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Metaloproteinase 2 da MatrizRESUMO
We analyzed the soil physico-chemcial properties, microbial community structure, petroleum hydrocarbon contents and components in soil samples from the well sites of Shuguang, Huanxi-ling and Jinzhou oil exploitation sites in Liaohe Oilfield, with uncontaminated paddy soil as a control. The results showed that: 1) The soil around all the three oil exploitation sites were seriously polluted by petroleum with certain differences in the petroleum hydrocarbon contents and components. The average content of petroleum hydrocarbon in the soil of Shuguang and Huanxiling oil exploitation sites was two times higher than that of Jinzhou oil exploitation site. The content of resins and asphaltenes in the soil of Shuguang oil exploitation site was the highest, while the soils of Huan-xiling and Jinzhou oil exploitation sites had the highest alkane content, which accounting for more than 40% in all the sites. 2)Compared with the paddy soil, the microbial OTU numbers, Chao1 and Shannon indices in the soil of Jinzhou oil exploitation site increased. The dominant phyla and genera were similar in the soil of all oil exploitation sites but with large differences in abundance. The soil in Jinzhou oil exploitation site had higher abundance of Mycobacterium and Pseudomonas, while Sphingomonas and Nocardioides, Massilia in the soil of Shuguang oil exploitation site, and Lysobacter, Thiobacillus and Pseudomonas in the soil of Huanxiling oil exploitation site. 3) The abundances of Sphingomonas, Nocardioides, Thiobacillus, Massilia, Pseudomonas and the contents of total petroleum hydrocarbons, total organic carbon and resins and asphaltenes were significantly positively correlated, while Mycobacterium, Lysobacter and Pseudomonas were significantly positively correlated with the contents of total nitrogen and total phosphorus. This study systematically analyzed the petroleum hydrocarbon, physico-chemcial properties and microbial communities in the soil of different oil exploitation sites, and revealed the specific dominant bacterial genera and microbial communities in the soil of Liaohe Oilfield. Our results provided a theoretical basis for functional bacterium screening and microbial community construction in the remediation process of petroleum contaminated soil in Liaohe Oilfield, and a reference for efficient degradation bacteria screening in other oilfields.
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Microbiota , Poluição por Petróleo , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Campos de Petróleo e Gás , Solo , Microbiologia do Solo , Poluentes do Solo/análiseRESUMO
A field trial was conducted with abandoned Pb-Zn mine tailings to evaluate the effectiveness of amendments with different C/N/P ratios on plant growth, soil nutrients and enzyme activities, and heavy metal concentrations in plant tissues and the mine tailings. The following results were noted. â The application of amendments with different C/N/P ratios promoted plant growth and development. The vegetation cover and biomass increased from 2.0%-20.0% and 9.4-115 g·m-2 at 6 months to 62.5%-98.5% and 389-2358.3 g·m-2 at 30 months, respectively. â¡When compared with the control tailings, the mean values of organic carbon, water organic carbon, nitrate nitrogen, and available phosphorus in the treatments with different C/N/P ratios increased 6.0%-93.3%, 1.3%-49.3%, 12.3%-214.7%, and 2.7%-81.3%, respectively. Similarly, the addition of amendments with different C/N/P ratios enhanced the soil enzyme activities of dehydrogenase, ß-glucosidase, urease, and phosphatase 0.3-2.8, 0.1-1.4, 0.1-0.6, and 0.1-0.5 times those in the tailings. â¢The addition of amendments with different C/N/P ratios decreased the concentrations of diethylenetriamine pentaacetate (DTPA)-extracted Cd, Cu, Pb, and Zn in the mine tailings and the accumulation of Cd, Cu, Pb, and Zn in plant tissues in different degrees. DTPA-Cd, DTPA-Cu, DTPA-Pb, and DTPA-Zn decreased 2.5%-40.2%, 1.4%-25.6%, 1.4%-15.2%, and 0.4%-24.9%, respectively, compared with the control tailings. â£Pearson's correlation coefficients showed that the vegetation cover and biomass were correlated positively with the soil nutrient elements and enzyme activities and negatively with DTPA-extractable metal concentrations. No correlations were observed between the plant metal concentrations and soil DTPA-extractable metal concentrations, nutrient elements, and enzyme activities. Generally, amendments with different C/N/P ratios aided phytostabilization of some types of mine tailings is the preferred option for full remediation of these mine wastelands.
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Metais Pesados , Mineração , Poluentes do Solo , Chumbo , Plantas , Solo , ZincoRESUMO
To date, very few attempts have been made to systematically compare the effectiveness of agricultural and nonagricultural organic wastes for aided phytostabilization of mine tailings under field conditions. In this study, we performed a field trial to compare the effectiveness of three agricultural organic wastes: chicken manure (CM), crop straw (CS), and spent mushroom compost (SMC), with that of three nonagricultural organic wastes, municipal sludge (MS), medicinal herb residues (MHR), and sweet sorghum vinasse (SSV) for aided phytostabilization of a Pb-Zn mine tailings pond in Hunan Province, China. Eight plant species naturally established in the vicinity of the mine were selected and seeded onto trial plots. It was found that the CM-amended plots had the highest (p < 0.05) vegetation cover (86%) and biomass production (881 g m-2), compared to other treatments. CM was also one of the best amendments in terms of improving soil nutrient status, increasing activities of soil enzymes, and immobilizing soil Pb. In addition, CM-amended plots were characterized by their higher microbial diversity and distinct microbial community structure as compared to the control plots. MS was the second best amendment in promoting vegetation cover (71%) and biomass production (461 g m-2), and it performed as well as CM for improving nutrient status, immobilizing heavy metals, and increasing the activities of enzymes in the mine tailings. Suggestions for further lines of research are made in order to develop future investigations.
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Epilepsy is one of the prevalent and major neurological disorders, and approximately one-third of the individuals with epilepsy experience seizures that do not respond well to available medications. We investigated whether oxysophocarpine (OSC) had anticonvulsant and neuroprotective property in the pilocarpine (PILO)-treated mice. Thirty minutes prior to the PILO injection, the mice were administrated with OSC (20, 40, and 80 mg/kg) once. Seizures and electroencephalography (EEG) were observed, and then the mice were killed for Nissl and Fluoro-jade B (FJB) staining. The oxidative stress was measured at 24 h after convulsion. Western blot analysis was used to examine the expressions of the Bax, Bcl-2, and Caspase-3. In this study, we found that pretreatment with OSC (40, 80 mg/kg) significantly delayed the onset of the first convulsion and status epilepticus (SE) and reduced the incidence of SE and mortality. Analysis of EEG recordings revealed that OSC (40, 80 mg/kg) significantly reduced epileptiform discharges. Furthermore, Nissl and FJB staining showed that OSC (40, 80 mg/kg) attenuated the neuronal cell loss and degeneration in hippocampus. In addition, OSC (40, 80 mg/kg) attenuated the changes in the levels of Malondialdehyde (MDA) and strengthened glutathione peroxidase and catalase activity in the hippocampus. Western blot analysis showed that OSC (40, 80 mg/kg) significantly decreased the expressions of Bax, Caspase-3 and increased the expression of Bcl-2. Collectively, the findings of this study indicated that OSC exerted anticonvulsant and neuroprotective effects on PILO-treated mice. The beneficial effects should encourage further studies to investigate OSC as an adjuvant in epilepsy, both to prevent seizures and to protect neurons in brain.
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Alcaloides/uso terapêutico , Anticonvulsivantes/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Pilocarpina/toxicidade , Convulsões/metabolismo , Convulsões/prevenção & controle , Fatores Etários , Alcaloides/farmacologia , Animais , Anticonvulsivantes/farmacologia , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos ICR , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Convulsões/induzido quimicamente , Resultado do TratamentoRESUMO
It is of great practical significance to rapidly screen the mixed microbial flora for degradation of complex organic pollutants. It was the first time to rapidly calibrate the petroleum hydrocarbon degradation ability of highly efficient degrading microflora by measuring enzyme activity analyzed by the MicroRespTM technology. The results were validated by the traditional shaking culture. According to the activity analysis of exoenzymes, endoenzymes and mixed enzymes, the degradation abilities of microflora and enzymes (including exoenzymes, endoenzymes and mixed enzymes) on petroleum hydrocarbon was investigated. The results showed that the enzyme activity assay had perfect sensitivity and high-throughput for rapidly detecting the degradation ability of the petroleum hydrocarbon. The test period was 12 h which was 10 times shorter than shaking culture for 120 microflora combinations. The maximum degradation extent of the petroleum hydrocarbon by microflora reached (56.1±1.6)%. It was concluded that the method of enzyme activity assay was high-efficient and high-throughput screening, which could be used in the construction of petroleum-degrading microflora.
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Biodegradação Ambiental , Petróleo , Microbiologia do Solo , Hidrocarbonetos , Poluentes do SoloRESUMO
A field trial was conducted in an abandoned Pb/Zn mine tailings to evaluate the effectiveness of three industrial wastes [sweet sorghum vinasse (SSV), medicinal herb residues (MHR) and spent mushroom compost (SMC)] as organic amendments on plant growth, soil nutrients and enzyme activities, and heavy metal concentrations in plant tissues and the mine tailings. (1) The main findings were as follows: (1) The mean concentrations of diethylene-triamine-pentaacetic acid (DTPA)-extractable Cd, Cu, Pb and Zn in SSV, MHR and SMC treatments decreased by 24.2%-27.3%, 45.7%-48.3%, 18.0%-20.9% and 10.1%-14.2% as compared to the control tailings. When compared to the control tailings, the mean values of organic matter, ammonium-N and available P in SSV, MHR and SMC treatments increased by 2.27-2.32, 12.4-12.8 and 4.04-4.74 times, respectively. Similarly, the addition of SSV, MHR and SMC significantly enhanced soil enzyme activities (dehydrogenase, beta-glucosidase, urease and phosphatase), being 5.51-6.37, 1.72-1.96, 6.32-6.62 and 2.35-2.62 times higher than those in the control tailings. (2) The application of these wastes promoted seed germination and seedling growth. The vegetation cover reached 84%, 79% and 86% at SSV, MHR and SMC subplots. For Lolium perenne and Cynodon dactylon, the addition of SSV, MHR and SMC led to significant increases in the shoot biomass yields with 4.2-5.6 and 15.7-17.3 times greater than those in the tailings. Moreover, the addition of SSV, MHR and SMC significantly reduced the concentrations of Cd, Cu, Pb and Zn in the shoots of L. perenne and C. dactylon in comparison with the control tailings. (3) Pearson's correlation coefficients showed that the vegetation cover and biomass were positively correlated with soil nutrient elements and enzyme activities. Significant negative correlations were observed between DTPA-extractable metal concentrations and vegetation cover and biomass. The metal concentrations in plants were positively correlated with soil DTPA-extractable metal concentrations and negatively correlated with soil nutrient elements and enzyme activities. The results obtained in this field study confirmed that the three organic-rich industrial wastes could be used as amendments for aided phytostabilization of some types of mine tailings.
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Resíduos Industriais , Chumbo/química , Lolium/crescimento & desenvolvimento , Mineração , Poluentes do Solo/química , Zinco/química , Biomassa , Desenvolvimento Vegetal , Solo/químicaRESUMO
In this study, a total of 73 groups of paddy soil and rice samples were collected from 3 counties of Xiangtan City, Hunan Province, which were Xiangtan, Yuhu, and Xiangxiang, respectively. The total content of Cd in soil and rice samples was determined, the available Cd in soil samples also was measured, and the correlation analysis was conducted among them, respectively. According to the prior probability and data feature, we proposed to use the Bayesian method to eva-luate the risk of Cd content exceeding criterion in rice and construct the risk assessment model. The results indicated that, the average soil Cd content, soil available Cd content and the rice Cd content in the study area were (0.891±0.638) mg·kg-1, (0.791±0.582) mg·kg-1 and (0.376±0.395) mg·kg-1, respectively, and the exceeding standard rate of Cd content in soil and rice reached 89.0% and 52.1%. The rice Cd content was significantly correlated with the available Cd content and total Cd content in soil in Xiangtan and Yuhu. A better correlation was presented between the soil available Cd content and rice Cd content. The rice Cd content in Xiangxiang had no correlation with total Cd content and available Cd content in soil. When the total Cd content and available Cd content were selected as the variables of Bayesian model, the deviations between the predicted exceeding probability of Cd in rice and the true exceeding standard rate were 6.6% and 3.9%, respectively, which proved the Bayesian risk assessment model was reliable. Selecting the available Cd content as the model variable, the predicted result was closer to the true value.
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Cádmio/análise , Oryza/química , Poluentes do Solo/análise , Teorema de Bayes , China , Medição de Risco , SoloRESUMO
PURPOSE: To discuss the clinical effects of submental island flap on repairing oropharynx defects after cancer ablation, and provide experience for clinical application. METHODS: Thirteen oropharyngeal cancer patients were included, and they were repaired with submental island flaps in oropharynx regions after cancer ablation and radical neck dissection. Among them, 12 patients were squamous cell carcinoma, and 1 patient was carcinoma. RESULTS: Of the 13 flaps used, 12 submental island flaps survived, only 1 flap had partial necrosis at the distal margin, which healed after triming and dressing. The follow-up time was 3 months to 3 years, and tumor recurrence or metastasis was not noted. All patients got good eating and speech functions. CONCLUSIONS: Submental island flap is safe and effective for repairing small or middle sized oropharynx defects after cancer ablation, which is located in the area of radical neck dissection, and has the advantages of simple operation,hidden incision and fewer lymph node metastasis in level I. Submental island flap has excellent clinical usefulness.
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Procedimentos de Cirurgia Plástica , Resultado do Tratamento , Carcinoma de Células Escamosas , Humanos , Esvaziamento Cervical , Orofaringe , Neoplasias Faríngeas , Retalhos CirúrgicosRESUMO
This paper revaluated the situation of cadmium (Cd) pollution in rice field soils of Zhangshi irrigation area in Shenyang. The results indicated that the soil Cd pollution of test area was still quite serious. The Cd content in brown rice samples ranged from 0.435 to 0.855 mg x kg(-1), which exceeded the national criteria for food sanitation in China, and increased by 335%-755% compared with that 20 years ago. Brown rice Cd had a significant negative correlation with soil pH, and a positive correlation with soil available Cd. The decrease of soil pH induced more soil Cd transformed into available Cd which occupied 22.8%-52.0% of the total Cd and was easy to be absorbed by rice plant, inducing the Cd in brown rice exceeded national criteria. The pollutant Cd could transfer along with surface runoff, ground water and flying dust, making the pollution extend gradually.
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Cádmio/análise , Metais Pesados/análise , Oryza/metabolismo , Poluentes do Solo/análise , Biodegradação Ambiental , China , Concentração de Íons de Hidrogênio , Oryza/química , Solo/análise , Movimentos da ÁguaRESUMO
The genus Xanthomonas contains plant pathogens exhibiting innate resistance to a range of antimicrobial agents. In other genera, multidrug resistance is mediated by a synergy between a low-permeability outer membrane and expression of a number of multidrug efflux systems. This report describes the isolation of a novel gene cluster xmeRSA from Xanthomonas strain IG-8 that mediates copper chloride resistance. Subsequent analysis of these genes showed that they were responsible for the high level of multiple resistance in this strain and were homologues of the sme system of Stenotrophomonas maltophilia. Knock-out mutants of this gene cluster indicate that these genes are required for the copper resistance phenotype of strain IG-8. Expression analysis using lacZ fusions indicates that the genes are regulated by copper and other antimicrobials. Bioinformatic analysis suggests that these genes were acquired by horizontal gene transfer.
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Proteínas de Bactérias/metabolismo , Cobre/farmacologia , Farmacorresistência Bacteriana Múltipla , Proteínas de Membrana Transportadoras/metabolismo , Família Multigênica , Xanthomonas/efeitos dos fármacos , Proteínas de Bactérias/genética , China , Biologia Computacional , Regulação Bacteriana da Expressão Gênica , Transferência Genética Horizontal , Proteínas de Membrana Transportadoras/genética , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Análise de Sequência de DNA , Xanthomonas/genética , Xanthomonas/isolamento & purificaçãoRESUMO
The study for biointerfaces at different scales in the past years has pricked up the march of biological sciences, in which biomembrane concept and its characteristics, receptor proteins, ion channel proteins, LEA proteins, calcium and newly recognized second messengers, ROS, MAPKs and their related sensors and new genes in osmoregulation, signal transduction, and other aspects have been understood fully, widening area of understanding the extensive interactions from biosystem and biointerfaces. The related discipline, plant stress physiology, especially, crop stress physiology has gained much attention world widely, the important reason of which is from the reducing quality of global ecoenvironment and decreasing food supply. This short review will place a stress on the recent progresses in plant stress physiology, combined with the new results from our State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau.
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Fenômenos Fisiológicos Vegetais , Plantas , Biologia de Sistemas , Adaptação Fisiológica , Fosfotransferases/metabolismo , Plantas/metabolismo , Sistemas do Segundo MensageiroRESUMO
Marine sediments from Lianshan Bay in Huludao, China, were studied in laboratory. A series of simulated experiments were carried out to investigate the influences of three kinds of anions Cl-, SO42- and HCO3 on the release of Cd, Pb, Cu and Zn from the sediments. The results showed that the sequences about the impact of the three anions were Cl- >HCO3 > SO42. The release potential of heavy metals in the presence of each anions was in the following order: Cd>>Cu>Zn approximately equal to Pb. The correlations were positive between Cl content and the quantity of Cd released from the marine sediment, whereas there was no significant relationship between Cl-content and amount of Cu and Zn released. For SO42- and HCO3-, the release of the heavy metals from marine sediments was not obvious.
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Ânions/química , Poluentes Ambientais/química , Sedimentos Geológicos/análise , Metais Pesados/química , China , Poluentes Ambientais/análise , Metais Pesados/análise , Espectrofotometria AtômicaRESUMO
In order to investigate the adsorption mechanism of trace metals to surficial sediments (SSs), a selective extraction procedure was improved in the present work. The selective extraction procedure has been proved to selectively remove and separate Fe, Mn oxides and organic materials (OMs) in the non-residual fraction from the SSs collected in Songhua River, China. After screening different kinds of conventional extractants of Fe and Mn oxides and OMs used for separation of heavy metals in the soils and sediments, NH2OH x HC1 (0.1 mol/L) + HNO3 (0.1 mol/L), (NH4)2C204 (0.2 mol/L) + H2C2O4 (pH 3.0), and 30% of H2O2 were respectively applied to selectively extract Mn oxides, Fe/Mn oxides and OMs. After the extraction treatments, the target components were removed with extraction efficiencies between 86.09% -93.36% for the hydroxylamine hydrochloride treatment, 80.63% -101.09% for the oxalate solution extraction, and 94.76%-102.83% for the hydrogen peroxide digestion, respectively. The results indicate that this selective extraction technology was effective for the extraction and separation of Fe, Mn oxides and OMs in the SSs, and important for further mechanism study of trace metal adsorption onto SSs.
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Poluentes Ambientais/isolamento & purificação , Compostos Férricos/isolamento & purificação , Sedimentos Geológicos/análise , Óxido de Magnésio/isolamento & purificação , Adsorção , China , Poluentes Ambientais/análise , Compostos Férricos/análise , Peróxido de Hidrogênio , Hidroxilamina , Óxido de Magnésio/análise , Oxalatos , RiosRESUMO
Glyphosate has been used globally as a safe herbicide for weed control. It inhibits 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase (AroA), which is a key enzyme in the aromatic amino acid biosynthetic pathway in microorganisms and plants. A Pseudomonas putida strain, 4G-1, was isolated from a soil heavily contaminated by glyphosate in China. Its AroA-encoding gene (aroA) has been cloned, sequenced, and expressed in Escherichia coli. Phylogenetic analysis revealed that this AroA belongs neither to class I nor to class II AroA enzymes. When compared with E. coli AroA, 4G-1 AroA shows similar values for K(m)[PEP], K(m)[S3P], and specific enzyme activity. Moreover, 4G-1 AroA exhibits high tolerance to glyphosate, which indicates a protein with a high potential for structural and functional studies of AroA in general and its potential usage for the generation of transgenic crops resistant to the herbicide.