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1.
Environ Res ; 251(Pt 1): 118389, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38460661

RESUMO

Phytoremediation has emerged as a common technique for remediating Cd pollution in farmland soil. Moreover, phosphorus, an essential element for plants, can alter the pectin content of plant cell walls and facilitate the accumulation of Cd in plant tissues, thereby enhancing phytoremediation efficiency. Therefore, pot experiments were conducted in order to investigate the effect of phosphorus levels on Cd extraction, phosphorus transformation and phosphorus-related genes during phytoremediation. The results revealed that an optimal application of suitable phosphate fertilizers elevated the soil's pH and electrical conductivity (EC), facilitated the conversion of soil from insoluble phosphorus into available forms, augmented the release of pertinent enzyme activity, and induced the expression of phosphorus cycling-related genes. These enhancements in soil conditions significantly promoted the growth of ryegrass. When applying phosphorus at a rate of 600 mg/kg, ryegrass exhibited plant height, dry weight, and chlorophyll relative content that were 1.27, 1.26, and 1.18 times higher than those in the control group (P0), while the Cd content was 1.12 times greater than that of P0. The potentially toxic elements decline ratio and bioconcentration factor were 42.86% and 1.17 times higher than those of P0, respectively. Consequently, ryegrass demonstrated the highest Cd removal efficiency under these conditions. Results from redundancy analysis (RDA) revealed a significant correlation among pH, total phosphorus, heavy metal content, phosphorus forms, soil enzyme activity, and phosphorus-related genes. In conclusion, this study suggests applying an optimal amount of suitable phosphate fertilizers can enhance restoration efficiency, leading to a reduction in soil Cd content and ultimately improving the safety of crop production in farmlands.


Assuntos
Biodegradação Ambiental , Cádmio , Lolium , Fósforo , Poluentes do Solo , Poluentes do Solo/metabolismo , Poluentes do Solo/análise , Cádmio/metabolismo , Fósforo/metabolismo , Fósforo/análise , Lolium/metabolismo , Lolium/genética , Lolium/crescimento & desenvolvimento , Fertilizantes/análise , Solo/química
2.
J Mater Chem B ; 12(10): 2435-2458, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38284157

RESUMO

Skin wounds significantly impact the global health care system and represent a significant burden on the economy and society due to their complicated dynamic healing processes, wherein a series of immune events are required to coordinate normal and sequential healing phases, involving multiple immunoregulatory cells such as neutrophils, macrophages, keratinocytes, and fibroblasts, since dysfunction of these cells may impede skin wound healing presenting persisting inflammation, impaired vascularization, and excessive collagen deposition. Therefore, cellular target-based immunomodulation is promising to promote wound healing as cells are the smallest unit of life in immune response. Recently, immunomodulatory hydrogels have become an attractive avenue to promote skin wound healing. However, a detailed and comprehensive review of cellular targets and related hydrogel design strategies remains lacking. In this review, the roles of the main immunoregulatory cells participating in skin wound healing are first discussed, and then we highlight the cellular targets and state-of-the-art design strategies for immunomodulatory hydrogels based on immunoregulatory cells that cover defect, infected, diabetic, burn and tumor wounds and related scar healing. Finally, we discuss the barriers that need to be addressed and future prospects to boost the development and prosperity of immunomodulatory hydrogels.


Assuntos
Hidrogéis , Cicatrização , Hidrogéis/farmacologia , Queratinócitos , Imunidade , Imunomodulação
4.
J Hazard Mater ; 445: 130614, 2023 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-37056003

RESUMO

Heavy metals (HMs) discharged from smelting production may pose a major threat to human health and soil ecosystems. In this study, the spatial distribution characteristics of HMs in the soil of a non-ferrous metal smelting site were assessed. This study employed the geodetector (GD) by optimizing the classification condition and supplementing the correlation analysis (CA). The contribution of driving factors, such as production workshop distributions, hydrogeological conditions, and soil physicochemical properties, to the distribution of HMs in soil in the horizontal and vertical dimensions was assessed. The results showed that the main factors underlying the spatial distribution of As, Cd, Hg, Pb, Sb, and Zn in the horizontal direction were the distance from the sintering workshop (the maximum q value of that factor, q=0.28), raw material yard (q=0.14), and electrolyzer (q=0.29), while those in the vertical direction were the soil moisture content (q=0.17), formation lithology (q=0.12), and soil pH (q=0.06). The findings revealed that the CA is a simple and effective method to supplement the GD analysis underlying the spatial distribution characteristics of HMs at site scale. This study provides useful suggestions for environmental management to prevent HMs pollution and control HMs in the soil of non-ferrous metal smelting sites.

6.
Front Oncol ; 12: 1020805, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36248985

RESUMO

Introduction: There are numerous findings over the past decade have indicated that Merkel cell carcinoma (MCC) may have two pathways of pathogenesis: one related to ultraviolet irradiation and the other to the Merkel cell polyomavirus (MCPyV). However, the predictive and clinicopathological value of MCPyV positivity in MCC patients is still debatable. This article aims to examine the most recent data regarding this issue. Methods: The thorough literature searches were conducted in the Medline Ovid, PubMed, Web of Science, the Cochrane CENTRAL Databases, and Embase Databases until December 31, 2021. The associations between overall survival (OS), Merkel cell carcinoma-specific survival (MSS), recurrence-free survival (RFS), progression-free survival (PFS), clinicopathologic features, and MCPyV positivity were examined in our meta-analysis. Results: This meta-analysis included a total of 14 studies involving 1595 patients. Our findings demonstrated a significant correlation between MCPyV positivity and improved OS (HR=0.61, 95%CI:0.39-0.94, P=0.026) and improved PFS (HR=0.61, 95% CI: 0.45-0.83, P=0.002). MCPyV positivity did not, however, appear to be associated with either MSS (HR=0.61, 95%CI: 0.28-1.32, P=0.209) or RFS (HR= 0.93, 95%CI: 0.37-2.34, P=0.873). Pooled results revealed a correlation between MCPyV positivity with gender (male vs. female, OR=0.606, 95%CI: 0.449-0.817, P=0.001), histopathological stage (AJCC I-II vs. III-IV, OR=1.636, 95%CI: 1.126-2.378, P=0.010) and primary site (head and neck vs. other sites, OR=0.409, 95%CI: 0.221-0.757, P=0.004). Conclusion: These results imply that MCPyV positivity may present a promising predictive biomarker for human MCC and call for further study.

7.
Aesthetic Plast Surg ; 46(6): 2841-2852, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35301571

RESUMO

BACKGROUND: Scarpa fascia preservation has been proposed to minimize complications associated with conventional abdominoplasty, but its efficacy is unclear. The purpose of this article is to determine the influence of preserving scarpa fascia on reducing postabdominoplasty complications. METHODS: A comprehensive search of Medline Ovid, PubMed, Web of Science, and the Cochrane CENTRAL databases was conducted from the inception till June 2021. Eligible studies were prospective controlled studies investigating postoperative complications after scarpa fascia preservation following abdominoplasty. Stata 15.1 software was used for the meta-analysis. RESULTS: The meta-analysis included seven studies with 682 abdominoplasty patients. Abdominoplasty with scarpa fascia preservation could significantly reduce incidence of seroma (OR = - 1.34, 95% CI = - 2.09 - - 0.59, P < 0.05), length of hospital stay (SMD = - 1.65; 95% CI = - 3.50-0.20; P = 0.08), time to drain removal (SMD = - 3.64; 95% CI = - 5.76 - - 1.52; P < 0.05), and total drain output (SMD = - 401.60; 95% CI = - 593.75 - - 209.44; P < 0.05) compared with that of conventional abdominoplasty. However, it failed to achieve a statistically significant reduction in hematoma (OR=- 1.30, 95% CI = - 2.79-0.18, P = 0.08), infection (OR = - 1.03; 95% CI = - 2.17-0.12; P = 0.08), skin necrosis (OR = 0.63; 95% CI = - 1.20-2.45; P = 0.50), and wound dehiscence (OR = 0.28; 95% CI = - 0.28-0.83; P = 0.33). The seroma incidence rate was lower when a scalpel was utilized for dissection rather than electrocautery (3% (95% CI = 1-7%) versus 11% (95% CI = 5-18%)). CONCLUSIONS: Preservation of scarpa fascia during abdominoplasty might reduce the likelihood of postoperative seroma, length of hospital stay, time to drain removal, and total drain output. However, it did not significantly affect the incidence of hematoma, infection, skin necrosis, and wound dehiscence. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Assuntos
Estudos Prospectivos , Humanos , Necrose
8.
Chemosphere ; 287(Pt 2): 132211, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826913

RESUMO

In this study, MoS2@Z photocatalysts were synthesized by combining ultrasonic and hydrothermal methods, and used for the degradation of tetracycline. The structure characteristics and photocatalytic degradation mechanism of photocatalysts were also systematically investigated. The obtained MoS2@Z-5 exhibits the highest photo-degradation efficiency of tetracycline (87.23%), which is 3.58 times more than alkali-modified zeolite (24.34%) and 1.80 times more than pure MoS2 (48.53%). Furthermore, the MoS2@Z-5 showed significant stability in three times photocatalytic recycles and the removal efficiency only decrease by 9.03%. Crystal structure and micromorphology analysis show modified zeolite with collapsed structure can regulate the morphology of nano-MoS2 and make MoS2 appear fault structure, which can expose more active sites. In addition, low Si/Al ratio zeolite increases the hydrophilia of MoS2@Z-5. Reactive-species-trapping experiments show that the hole is the main reactive oxidizing species. The superior photo-degradation efficiency is mainly attributed to outstanding hydrophilia, exposure of the edge active sites, and efficient separation of photogenerated charge and holes. A possible photocatalytic mechanism and degradation pathways of tetracycline were proposed. The results indicate that MoS2@Z-5 may become an efficient, stable, and promising photocatalyst in tetracycline wastewater treatment.


Assuntos
Molibdênio , Zeolitas , Antibacterianos , Catálise , Tetraciclina
9.
Ann Plast Surg ; 86(2): 175-181, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32756249

RESUMO

BACKGROUND: Weak alar cartilage and lack of soft tissue on the cleft side are considered to be the main critical factors leading to the asymmetry of bilateral nostrils. The costal cartilage can provide strong structural support and can be used to maintain long-term stability of nostril shape after surgical correction. With the advancement in rhinoplasty techniques, the application and understanding of costal cartilage in cleft lip nasal deformity is still on going. Herein, we present our technique of applying costal cartilage to provide nostril support and correct asymmetry in Asian patients with unilateral secondary cleft lip nasal deformity. METHODS: Ninety-seven patients who underwent nostril asymmetry correction from January 1, 2013, to October 31, 2018, were analyzed retrospectively. Modified integrative alar cartilage strut and diced nostril augmentation with costal cartilage were implemented to improve the collapsed and flat cleft-side nostril. The release and restoration of muscle and bone were also performed when required. Surgical outcomes were analyzed based on the comparison of nostril parameters, the shape and contour, and symmetry of bilateral nostrils after surgery. During postoperative follow-up, the patients' satisfactions with the corrective outcomes were also investigated. RESULTS: All patients received the corrective operations with complete survival of all implanted cartilages. The nostril width was narrower in postoperative group (P < 0.05). The nostril height and long axis angle were higher postoperatively (P < 0.05). After correction, the proportion of moderate type increased from 13.4% to 80.4%, whereas the proportion of horizontal type decreased from 86.6% to 17.5%. The symmetry score on the nostril parameters manifested the rate of high score (AS >3) in postoperative groups were 84.5%, 93.8%, and 87.6% for width, height, and angle of the long axis, respectively. They were higher compared with those of preoperative group (0%). More than 95% of the patients were satisfied with the overall aesthetic outcome of the surgery. CONCLUSIONS: Through ameliorating its constructive technology and optimizing its filling form, the modified use of costal cartilage displayed excellent correction effects in the width, height, and long axis angle asymmetry of Asian patients' nostril. Precise and comprehensive rhinoplasty technique is the cornerstone for achieving satisfactory long-term aesthetic outcomes, especially in severe cases, such as secondary cleft lip nasal deformity.


Assuntos
Fenda Labial , Cartilagem Costal , Rinoplastia , Povo Asiático , Fenda Labial/complicações , Fenda Labial/cirurgia , Humanos , Nariz/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
10.
J Hazard Mater ; 401: 123269, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-32623308

RESUMO

A stable, urease-producing consortium (UPC) was constructed for high-efficiency cadmium (Cd) ion mineralization via a short-term and efficient acclimation process (five acclimation transfers). 16S rRNA gene high-throughput sequencing and quantitative polymerase chain reaction (qPCR) analyses of the urease subunit C (ureC) gene suggested that the three functional genera, all belonging to the phylum Firmicutes, rapidly increased during the process and finally composed the UPC (70.22-75.41 % of Sporosarcina, 13.83-20.66 % of norank_f_Bacillaceae, and 5.91-13.69 % of unclassified_f_Bacillaceae). The UPC exhibited good adaptability to a wide range of environmental conditions (a pH range of 4.0-11.0, temperature range of 10-45 °C, and Cd concentration range of 0-200 mg L-1). After 8 h of incubation, 92.87 % of Cd at an initial concentration of 100 mg L-1 was mineralized by UPC, exhibiting a great improvement as compared to the first acclimated consortium (C-1). Furthermore, although the acclimated consortium had been successively transferred 21 times, the Cd biomineralization efficiency remained stable, and this was consistent with the observed stable microbial community structure. X-ray diffraction (XRD) spectra revealed that Cd was mineralized in a (Ca0.67, Cd0.33)CO3 phase. This research obtained a promising microbial resource for the biomineralization of Cd or other hazardous heavy metal contaminants.


Assuntos
Biomineralização , Cádmio , Carbonato de Cálcio , Carbonatos , RNA Ribossômico 16S/genética
11.
Breast ; 53: 189-200, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32858404

RESUMO

BACKGROUND: The axillary reverse mapping (ARM) technique, identify and preserve arm nodes during sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND), was developed to prevent breast-cancer related lymphedema (BCRL) remains controversial. METHODS: A comprehensive search of Medline Ovid, Pubmed, Web of Science and the Cochrane CENTRAL databases was conducted from the inception till January 2020. The key word including "breast cancer", "axillary reverse mapping", and "lymphedema". Stata 15.1 software was used for the meta-analysis. RESULTS: As a result, twenty-nine related studies involving 4954 patients met our inclusion criteria. The pooled overall estimate lymphedema incidence was 7% (95% CI 4%-11%, I2 = 90.35%, P < 0.05), with SLNB showed a relatively lower pooled incidence of lymphedema (2%, 95% CI 1%-3%), I2 = 26.06%, P = 0.23) than that of ALND (14%, 95% CI 5%-26%, I2 = 93.28%, P < 0.05) or SLNB and ALND combined (11%, 95% CI 1%-30%). The ARM preservation during ALND procedure could significantly reduce upper extremity lymphedema in contrast with ARM resection (OR = 0.27, 95% CI 0.20-0.36, I2 = 31%, P = 0.161). Intriguingly, the result favored ALND-ARM over standard-ALND in preventing lymphedema occurrence (OR = 0.21, 95% CI 0.14-0.31, I2 = 43%, P = 0.153). The risk of metastases in the ARM-nodes was not significantly lower in the patients who had received neoadjuvant chemotherapy, as compared to those without neoadjuvant treatment (OR = 1.20, 95% CI 0.74-1.94, I2 = 49.4%, P = 0.095). CONCLUSIONS: ARM was found to significantly reduce the incidence of BCRL. The selection of patients for this procedure should be based on their axillary nodal status. Preoperative neoadjuvant chemotherapy has no significant impact on the ARM lymph node metastasis rate.


Assuntos
Linfedema Relacionado a Câncer de Mama/prevenção & controle , Neoplasias da Mama/patologia , Excisão de Linfonodo/efeitos adversos , Linfonodos/patologia , Complicações Pós-Operatórias/prevenção & controle , Adulto , Idoso , Axila , Linfedema Relacionado a Câncer de Mama/etiologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Incidência , Metástase Linfática/diagnóstico , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Medição de Risco , Biópsia de Linfonodo Sentinela/métodos
12.
Ecotoxicol Environ Saf ; 198: 110660, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32361492

RESUMO

In situ immobilization of heavy metal cations in contaminated soil using natural minerals is an attractive remediation technique. However, little research has focused on the remediation of arsenic (As) and cadmium (Cd) co-contaminated. In this work, three different crystal structures and chemical compositions minerals, zeolite; bentonite; and dolomite, were applied to simultaneously reduce the uptake of As and Cd in Brassica chinensis L., and the mechanism on reducing As and Cd bioavailability in soil were also investigated. The results showed that the three minerals decreased the bioavailability of As and Cd and restrained their uptake by Brassica chinensis L. with the order followed bentonite > zeolite > dolomite. Particularly, bentonite decreased the exchangeable As and Cd by 4.05% and 32.5% and the concentrations of As and Cd in shoots of Brassica chinensis L. by 36.2% and 64.6%, as compared with the controls. Moreover, with the addition of minerals increased, the dry biomass of Brassica chinensis L. and the rhizosphere microbial functional diversity increased significantly, and the highest biomass increased by 289% at 4.0% addition of bentonite. Correlation analysis indicated that the uptake of As and Cd was positive with the available Cd and As in soil, and was negative with soil pH and available N. Furthermore, the Scanning Electron Microscopy-Energy Dispersive Spectroscopy and Fourier Transform Infrared Spectroscopy analysis illustrated the interaction between minerals and Cd mainly involved ion-exchange and adsorption, while As was mainly immobilized by calcium and magnesium through forming precipitation. In conclusion, this present study implied that the bentonite can be recommended as the more effective amendment to immobilize metal (loid)s in soil and thereby reduce the exposure risk of metal (loid)s associated with grains consumption.


Assuntos
Arsênio/análise , Bioacumulação , Brassica/efeitos dos fármacos , Cádmio/análise , Poluentes do Solo/análise , Agricultura , Arsênio/metabolismo , Bentonita/química , Disponibilidade Biológica , Biomassa , Brassica/metabolismo , Cádmio/metabolismo , Carbonato de Cálcio/química , Magnésio/química , Rizosfera , Solo/química , Poluentes do Solo/metabolismo , Zeolitas/química
13.
Environ Pollut ; 263(Pt A): 114479, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32276191

RESUMO

Hexavalent chromium and nitrate co-contaminated groundwater remediation are attracting extensive attention worldwide. However, the transformation pathways of chromium and nitrate and the interplay mechanism between them remain unclear. In this work, zeolite-supported nanoscale zero-valent iron/palladium (Z-Fe/Pd) was synthesized and used for the first time to simultaneously remediate Cr(VI) and nitrate. Transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses confirmed that nanoscale zero-valent iron/palladium was successfully loaded onto zeolite and it exhibited good dispersibility and oxidation resistance. Results of batch experiments showed that the Cr(VI) and nitrate removal efficiencies decreased from 95.5% to 91.5% to 45% and 73%, respectively, with the initial solution pH increasing from 3.0 to 8.0. The removal rates and efficiencies of Cr(VI) and nitrate under anoxic conditions were higher than those under open atmosphere because the dissolved oxygen diminished the electron selectivity toward the target pollutants. Moreover, the presence of Cr(VI) inhibited nitrate reduction by forming Fe(III)-Cr(III) hydroxide to impede electron transfer. Cr(VI) removal was promoted by nitrate, within limits, by balancing the consumption and generation rate of Fe3O4, which enhanced electron migration from the Fe(0) core to the external surface. The removal capacities of Cr(VI) and nitrate reached 121 and 95.5 mg g-1, respectively, which were superior to the removal capacities of similar materials. Results of product identification, XRD, and XPS analyses of spent Z-Fe/Pd indicated that the reduction of Cr(VI) was accompanied by adsorption and co-precipitation, whereas the reduction of nitrate was catalyzed by the synergism of Fe(0) and Pd(0). An alternative to the simultaneous remediation of Cr(VI) and nitrate from groundwater under anoxic conditions is provided.


Assuntos
Água Subterrânea , Poluentes Químicos da Água/análise , Zeolitas , Cromo/análise , Compostos Férricos
14.
Sci Total Environ ; 717: 137014, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32065885

RESUMO

Biochar plays a significant role in soil remediation. However, the simultaneous immobilization mechanism and relationship of biochar to cations and anions have never been clear. We designed a batch incubation experiment to investigate the impact of corncob-based biochars to cadmium (Cd) and arsenic (As) contaminations in yellow soil and cinnamon soil, and analyze the relationships among biochars physicochemical characteristics (surface area: SA, total pore volume: TV, average pore size: AV and the C/O rate), soil properties, metals immobilization and microbial diversity indices. Results showed that the modified biochars (inorganic-modified biochar: BCTD) had a good effect on heavy metals immobilization and transformed acid extractable and reducible fraction into the residual fraction. Total nitrogen, organic matter and available potassium increased in both soils after biochar application. The principal component analysis presented that the smaller C/O rate was favorable to As stabilization; the SA and TV of biochar were negatively correlated with the leaching concentration of Cd. The larger surface area, higher porosity and organic matters of biochar were more beneficial to soil microbial diversity. This work not only can demonstrate remediation mechanisms of heavy metals contaminated soil by biochars, but also gain an application of biochars technology in the recycling and reutilize of agricultural waste, and provide a clear strategy for heavy metals contaminated soil, especially As and Cd.


Assuntos
Zea mays , Arsênio , Cádmio , Carvão Vegetal , Cinnamomum zeylanicum , Recuperação e Remediação Ambiental , Solo , Poluentes do Solo
15.
Chemosphere ; 240: 124891, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31574442

RESUMO

We investigated the effects of endophytes inoculation on ecological factors such as root morphology, rhizosphere soil properties, heavy metal speciation, and rhizosphere and endophytic bacterial communities and their role on phytoremediation. Indian mustards were grown for two months in V-contaminated soil with three treatments (control, inoculation with Serratia PRE01 or Arthrobacter PRE05). Inoculation with PRE01 and PRE05 increased organic matter content by 6.94% and 4.6% respectively and significantly increased bioavailability of heavy metals in rhizosphere soils. Despite the endophyte inocula failed to flourish as stable endophytes, they significantly affected the specific composition and diversity of endophytic bacterial communities in roots, with no significant effect on rhizosphere bacterial communities. The test strains could greatly increase plant growth promotion-related biomarkers in the endosphere, especially those associated with Pseudomonas and Microbacterium genera. PICRUSt analysis predicted high relative abundances of functional genes related to environmental information processing especially in the endophytic microbiota. More biomass production (12.0%-17.4%) and total metals uptake (24.2%-32.0%) were acquired in inoculated treatments. We conclude that endophyte PRE01 or PRE05 inoculation could effectively enhance phytoremediation of V-contaminated soil by improving the rhizosphere and endosphere microecology without causing any ecological damage.


Assuntos
Bactérias/metabolismo , Biodegradação Ambiental , Endófitos/crescimento & desenvolvimento , Mostardeira/metabolismo , Rizosfera , Poluentes do Solo/toxicidade , Vanádio/toxicidade , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Mostardeira/efeitos dos fármacos , Mostardeira/microbiologia , Desenvolvimento Vegetal/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Microbiologia do Solo , Poluentes do Solo/análise , Vanádio/análise
16.
Sci Total Environ ; 695: 133862, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31425984

RESUMO

Recent growing evidence suggests that heavy metals can stimulate the transfer of antibiotic resistance genes (ARGs) between bacteria. However, most previous studies focused on pure strains, the effect of heavy metals on ARG transfer in bacterial communities, especially in activated sludge, has not been clearly explored. In this study, a high-throughput method, combining computerized incubator (Bioscreen C) and flow cytometry, was developed to evaluate different concentrations of heavy metals influencing ARG transfer in sludge bacteria communities. By using Escherichia coli MG1655 as the donor of broad-host range IncP-1 plasmid pKJK5, it was found that 0.5 mmol/L Pb, 0.1 mmol/L As and 0.005 mmol/L Hg could obviously promote ARG transfer in sludge bacteria communities. Furthermore, mating assays on microfluidic chips also proved higher transfer frequencies in attached communities under the above heavy metal stresses. Transconjugants under Pb, As and Hg stresses were isolated and phylogenetically described. For As and Hg, the dominant genus was Pseudomonas, accounting for 88% and 96%, respectively. While under Pb stress, the genera Aeromonas and Enterobacter were the main transconjugants, accounting for 56% and 32% respectively. Moreover, ABC transporters and Amino acid metabolism, which were related to heavy metal transport and cellular metabolism, were dominant in the prediction of microbial metabolic function of transconjugants. This study can be helpful for risk assessment and control of ARG spreading in WWTPs.


Assuntos
Resistência Microbiana a Medicamentos/genética , Metais Pesados/toxicidade , Esgotos/microbiologia , Poluentes Químicos da Água/toxicidade , Monitoramento Ambiental , Transferência Genética Horizontal , Esgotos/química
17.
Bioresour Technol ; 284: 333-339, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30953861

RESUMO

Simultaneous removal of cations and anions in wastewater has always been a great concerned environmental problem. In this study, a friendly and inexpensive biosorbent to simultaneously remove Cd(II) and As(V) from aqueous solution was synthesized by ultrasonic biochar and nanoscale TiO2 (TD), and the obtained sorbent was named as BCTD. The maximum sorption capacities of Cd (72.62 mg/g) and As (118.06 mg/g) were much higher than that of other carbon-materials. Both experiments showed that the Cd(II) and As(V) adsorption capacity was above 70% at pH = 5. The Cd(II) and As(V) adsorption on BCTD had a competitive effect in binary metal solutions at above 100 mg/L. The BET, SEM-EDS, FTIR and XPS analyses proved that ultrasonically reacting enhanced the surface area and pore volume of biochar and TD was supported on the biochar surface and inner pores successfully, and the dominant sorption mechanism by BCTD was the ion exchange and complexation.


Assuntos
Arsênio/isolamento & purificação , Cádmio/isolamento & purificação , Carvão Vegetal/química , Titânio/química , Poluentes Químicos da Água/química , Adsorção , Troca Iônica , Soluções/química , Ultrassom , Purificação da Água
18.
Ecotoxicol Environ Saf ; 169: 856-862, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30597785

RESUMO

Ecological floating beds (EFBs) is one of the effective methods lately used to remove heavy metals pollutions in water. However, the role of substrate in EFBs was mainly focused on the study of microorganisms, and the effect of substrates on plants enrichment of heavy metals was rarely investigated. This study aimed to investigate the promotion of different substrates (green zeolite, sepiolite, absorbent paper, and ceramsite) on the removal of multi-heavy metals (V, Cr, and Cd) by Acorus calamus L. It also investigated the plant growth status. Results showed that the relative increase rate of Acorus calamus L. fresh weight increased the most in EFBs with green zeolite group (EFB-GZ), which was 60.50%, higher than 38.17% in EFBs with Acorus calamus L. (EFB-A). The enrichment ability of multi-metals in Acorus calamus L. was stronger in EFBs with substrates than in EFB-A, and green zeolite was the best. After 34 days, the total removal efficiency of V, Cr and Cd in EFB-GZ were 79.91%, 95.24% and 91.80%, respectively. Heavy metals translocation from root to shoot influenced by the kinds of substrates. In EFB-GZ, the translocation factor (TF) of V, Cr and Cd were 0.081, 0.263 and 0.180, respectively (0.024, 0.608 and 0.032 in EFB-A). The ability of Acorus calamus L. to resist multi-metals stress was significantly higher in EFBs with substrates than that in EFB-A and the activity of SOD, POD and CAT were increased by heavy metals stress. Our results acquired that green zeolite was the best substrate to promote multi-metals uptake by Acorus calamus L., which could effectively maintain the pH of water, provide a stable environment and nutriment for Acorus calamus L. Green zeolite can promote the translocation of V and Cd from root to shoot in Acorus calamus L., but is not conducive to Cr.


Assuntos
Acorus/crescimento & desenvolvimento , Recuperação e Remediação Ambiental/métodos , Silicatos de Magnésio , Metais Pesados/análise , Rios/química , Poluentes Químicos da Água/análise , Zeolitas , Biodegradação Ambiental , Transporte Biológico , Cádmio/análise , Cromo/análise , Ecologia , Desenvolvimento Vegetal , Vanádio/análise , Água/química , Poluição da Água/análise
19.
Bioresour Technol ; 259: 312-318, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29573610

RESUMO

In order to improve the adsorption capacities of corncob-based biochars for heavy metal, the different pyrolysis temperature (350 °C, 450 °C and 550 °C) of corncob-based biochars were modified with the acrylonitrile, and adsorption capacities of Cadmium from solution by biochars were studied. The results showed that only at 350 °C the biochar can be successfully modified. The Cd adsorption capacity (85.65 mg/g) by the biosorbent was higher than other methods of modifying biochars previously reported. SEM-EDS and FTIR confirmed that the CN group was grafted on the biochar at low pyrolysis temperature. Batch adsorption experiment including pH-dependence, adsorption kinetics, and isotherms and XPS results showed that the removal mechanism of Cd(II) by the modified biochar was ion exchange and adsorption-complexation. This research not only obtained a novel method to modify biochar but also furthered research into the lignin of biochar composition, and provided an efficient sorbent for heavy metal.


Assuntos
Cádmio , Carvão Vegetal , Lignina , Adsorção , Água
20.
J Hazard Mater ; 341: 1-9, 2018 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-28759788

RESUMO

This study investigates the V-resistant endophytic bacteria isolated from V-accumulator Pteris vittata grown on stone coal smelting district. Among all the ten isolates, the strain PRE01 identified as Serratia marcescens ss marcescens by Biolog GEN III MicroPlate™ was screened out by ranking first in terms of heavy metal resistance and plant growth promoting traits. The S. marcescens PRE01 had strong V, Cr and Cd resistance especially for V up to 1500mg/L. In addition, it exhibited ACC deaminase activity, siderophore production and high indoleacetic acid production (60.14mg/L) and solubilizing P potential (336.41mg/L). For heavy metal detoxification tests, PRE01 could specifically assimilate 97.6%, 21.7% and 6.6% of Cd(II), Cr(VI) and V(V) within 72h incubation. Despite the poor absorption of the two anions, most V(V) and Cr(VI) were detoxified and reduced to lower valence states by the strain. Furthermore, the isolate had the potential to facilitate the metals uptake of their hosts by changing heavy metal speciation. Our research may open up further scope of utilizing the endophyte for enhancing phytoextraction of vanadium industry contaminated soils.


Assuntos
Bactérias/metabolismo , Endófitos/metabolismo , Pteris/metabolismo , Pteris/microbiologia , Poluentes do Solo/metabolismo , Vanádio/metabolismo , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Biodegradação Ambiental , Cádmio/metabolismo , Cromo/metabolismo , Carvão Mineral , Metalurgia
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