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1.
J Environ Manage ; 325(Pt B): 116407, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36302302

RESUMEN

The proportion of activated persulfate (PS) oxidation technology in the remediation of domestic organic contaminated sites has increased every year, and the potential corrosion risk of site reuse caused by residual oxidants and by-products has also attracted the attention of researchers. In this work, the potential corrosion degree such as the mass reduction rate and surface crack width of standard iron flakes under different conditions, including with different PS dosages and release times, was monitored quantitatively over a long period, and the corresponding corrosion risk was quantitatively assessed. The results showed that when n (Na2S2O8):n (PAHs) increased from 5:1 to 100:1, the higher the oxidizer dosage, the more severe the corrosion weight loss and surface crack width, indicating that the oxidizer dosage was positively correlated with the potential corrosion risk. In addition, the corrosion crack width of the standard iron flake had a significant positive correlation with the reaction time and a significant negative correlation with the mass change. According to the changes in the standard iron flake, the corrosion process could be divided into three stages, in which the corrosion risk from high to low followed the order of oxidant corrosion stage > oxidant and salt corrosion stage > salt and microbial corrosion stage. Therefore, the dosage of chemicals should be controlled, the molar ratio of oxidizer to contaminant should not exceed 25:1, and a natural recovery period of at least one year should be left post remediation. During the reuse of the remediation sites in the future, the potential corrosion risks should also be calculated based on the dosage and time, to avoid redevelopment and use of the restoration site in the high corrosion risk stage.


Asunto(s)
Restauración y Remediación Ambiental , Contaminantes del Suelo , Contaminantes del Suelo/análisis , Corrosión , Oxidación-Reducción , Hierro , Oxidantes , Suelo , Sulfatos
2.
Environ Geochem Health ; 43(1): 23-36, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32696201

RESUMEN

Soil pollution at industrial sites is an important issue in China and in most other regions of the world. The accurate prediction of the spatial distribution of pollutants at contaminated industrial sites is a requirement for the development of most soil remediation strategies, and is commonly performed using spatial interpolation methods. However, significant and abrupt variations in the spatial distribution of pollutants decrease prediction accuracy. During this study, the use of partition interpolation methods was applied to benzo fluoranthene in four soil layers at a contaminated site to determine their ability to improve prediction accuracy in comparison to unpartitioned methods. The examined methods for partitioned interpolation included inverse distance weighting (IDW), radial basis function (RBF), and ordinary kriging (OK). The prediction results of the three methods for partitioned interpolation were compared, and the applicability of partition interpolation was determined. The prediction error associated with the partitioned interpolation methods decreased by 70% compared to unpartitioned interpolation. The prediction accuracy of IDW-based partition interpolation was higher than that of RBF- and OK-based partition interpolation techniques, and it was suitable for identification of highly polluted areas. Partition interpolation is also applicable to 12 other PAHs controlled by USEPA that can be detected, and the prediction effects could also verify this interpolation choice. In addition, the results also demonstrated that the more the maximum concentration deviated from the "norm", the greater the prediction error was caused by the smoothing effects of the interpolation models. These results suggest that the partition interpolation with IDW method can be effectively used to obtain relatively accurate spatial contaminant distribution information, and to identify highly polluted areas.


Asunto(s)
Monitoreo del Ambiente/métodos , Contaminantes del Suelo/análisis , China , Contaminación Ambiental/análisis , Contaminación Ambiental/prevención & control , Fluorenos/análisis , Predicción , Análisis Espacial
3.
Ecotoxicol Environ Saf ; 190: 110092, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31874406

RESUMEN

Integrated chemical-biological treatment is a promising alternative to remove PAHs from contaminated soil, wherein indigenous bacteria is the key factor for the biodegradation of residual PAHs after the application of chemical oxidation. However, systematical study on the impact of persulfate (PS) oxidation on indigenous bacteria as well as PAHs removal is still scarce. In this study, the influences of different PS dosages (1%, 3%, 6%, and 10% [w/w]), as well as various activation methods (native iron, H2O2, alkaline, ferrous iron, and heat) on PAHs removal and indigenous bacteria in highly contaminated aged soil were investigated. Apparent degradation of PAHs in the soil treated with PS oxidation was observed, and the removal efficiency of total PAHs in the soil ranged from 38.28% to 79.97%. The removal efficiency of total PAHs in the soil increased with increasing consumption of PS. However, the bacterial abundance in soil was negatively affected following oxidation for all of the treatments added with PS, with bacterial abundance in the soil decreased by 0.89-2.93 orders of magnitude compared to the untreated soil. Moreover, the number of total bacteria in the soil decreased as PS consumption increased. Different PS activation methods and PS dosages exhibited different influences on the bacterial community composition. Bacteria capable of degrading PAHs under anoxic conditions were composed predominantly by Proteobacteria and Firmicutes. The total amount of Proteobacteria and Firmicutes also decreased with increasing consumption of PS. The results of this study provide important insight for the design of PAHs contaminated soil remediation projects.


Asunto(s)
Bacterias/metabolismo , Biodegradación Ambiental , Hidrocarburos Policíclicos Aromáticos/metabolismo , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Peróxido de Hidrógeno/metabolismo , Hierro/química , Oxidación-Reducción , Hidrocarburos Policíclicos Aromáticos/análisis , Suelo/química , Contaminantes del Suelo/análisis
4.
Environ Geochem Health ; 41(6): 2709-2730, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31144251

RESUMEN

Accurate prediction of the spatial distribution of pollutants in soils based on applicable interpolation methods is often the basis for soil remediation in contaminated sites. However, the applicable interpolation method has not been determined for contaminated sites due to the complex spatial distribution characteristics and stronger local spatial variability of pollutants. In this research, the prediction accuracies of three interpolation methods (including the different values of their parameters) for the spatial distribution of benzo[b]fluoranthene (BbF) in four soil layers were compared. These included inverse distance weighting (IDW), radial basis function (RBF), ordinary kriging (OK). The results indicated: (1) IDW1 is applicable for the first layer, RBF-IMQ is applicable to the second, third, and fourth layers. (2) For IDW, the prediction error is bigger with high weight where high values and low values intersect, while the prediction error is smaller where high (or low) values aggregated distribution. (3) For RBF, if the pollutant concentration trend at the predicted location is consistent with the known points in its neighborhood, the prediction accuracy is higher. (4) IDW is suitable for fitting more drastic curved surfaces, while RBF is more effective for relatively gentle curved surfaces and OK is reasonable for curved surfaces without local outliers. (5) The interpolation uncertainty is positively associated with the contaminant concentration and local spatial variability. Therefore, we suggest the selection of the applicable interpolation model must be based on the principle of the model and the spatial distribution characteristics of the pollutants.


Asunto(s)
Monitoreo del Ambiente/estadística & datos numéricos , Contaminantes del Suelo/análisis , China , Monitoreo del Ambiente/métodos , Fluorenos/análisis , Análisis Espacial , Incertidumbre
5.
J Food Sci Technol ; 55(12): 5035-5044, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30482999

RESUMEN

The aim of this study was to evaluate the effect of γ-aminobutyric acid (GABA) treatment on the enzymatic browning of fresh-cut potatoes. The browning index and activities of browning and defense-related enzymes were analyzed after 0, 1, 2, 3, 4, 5, and 6 days of storage at 4 °C. The results showed that the treatment with 20 g/L GABA for 10 min significantly retarded the browning of fresh-cut potatoes. GABA inhibited the browning of fresh-cut potatoes by enhancing the activities of catalase and superoxide dismutase, and decreasing the activities of polyphenol oxidase and reactive oxygen species. The results suggest that GABA plays an important role in reducing the browning of fresh-cut potatoes. Hence, GABA treatment is a promising approach for reducing the browning and maintaining the quality of fresh-cut potatoes.

6.
Ann Otol Rhinol Laryngol ; 124(3): 232-4, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25385841

RESUMEN

OBJECTIVE: The objective of the study was to investigate outcomes of recurrent facial palsy in Melkersson Rosenthal syndrome (MRS). METHODS: We carried out a prospective investigation on patients who had recurrent facial palsy in MRS and visited an outpatient department of otolaryngology from January 2002 to January 2012, focusing on their facial nerve outcomes. They were followed up for 12 months. The patients who visited our department due to recurrent Bell's palsy during the same period were selected as controls. Oral prednisolone alone was given to each patient. RESULTS: A total of 22 patients with recurrent facial palsy in MRS and 73 patients with recurrent Bell's palsy were included in the study. Twelve months later, only 3 of 22 patients (13.6%) who had recurrent facial palsy in MRS recovered to House-Brackmann grade I, whereas 52 of 73 patients (71.2%) who had recurrent Bell's palsy recovered completely. The difference was statistically significant (P<.01). CONCLUSION: Compared to recurrent Bell's palsy, recurrent facial palsy in MRS had much worse prognosis.


Asunto(s)
Nervio Facial/fisiopatología , Parálisis Facial/etiología , Síndrome de Melkersson-Rosenthal/complicaciones , Prednisolona/administración & dosificación , Recuperación de la Función , Administración Oral , Adulto , Parálisis Facial/tratamiento farmacológico , Parálisis Facial/fisiopatología , Femenino , Estudios de Seguimiento , Glucocorticoides/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recurrencia , Resultado del Tratamiento , Adulto Joven
7.
Ecotoxicol Environ Saf ; 113: 391-9, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25540851

RESUMEN

Anthropogenic emissions of toxic metals from smelters are a global problem. The objective of this study was to investigate the distribution of toxic metals in soils around a 60 year-old Pb/Zn smelter in a town in Yunnan Province of China. Topsoil and soil core samples were collected and analyzed to determine the concentrations of various forms of toxic metals. The results indicated that approximately 60 years of Pb/Zn smelting has led to significant contamination of the local soil by Zn, Pb, Cd, As, Sb, and Hg, which exhibited maximum concentrations of 8078, 2485, 75.4, 71.7, 25.3, and 2.58mgkg(-1), dry wet, respectively. Other metals, including Co, Cr, Cu, Mn, Ni, Sc, and V, were found to originate from geogenic sources. The concentrations of smelter driven metals in topsoil decreased with increasing distance from the smelter. The main contamination by Pb, Zn, and Cd was found in the upper 40cm of soil around the Pb/Zn smelter, but traces of Pb, Zn, and Cd contamination were found below 100cm. Geogenic Ni in the topsoil was mostly bound in the residual fraction (RES), whereas anthropogenic Cd, Pb, and Zn were mostly associated with non-RES fractions. Therefore, the smelting emissions increased not only the concentrations of Cd, Pb, and Zn in the topsoil but also their mobility and bioavailability. The hazard quotient and hazard index showed that the topsoil may pose a health risk to children, primarily due to the high Pb and As contents of the soil.


Asunto(s)
Metalurgia , Metales Pesados/análisis , Metales Pesados/toxicidad , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad , Niño , China , Humanos , Plomo/análisis , Medición de Riesgo , Suelo/química , Oligoelementos/análisis , Zinc/análisis
8.
J Hazard Mater ; 465: 133265, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38113745

RESUMEN

In situ anoxic bioremediation is a sustainable technology to remediate PAHs contaminated soils. However, the limited degradation rate of PAHs under anoxic conditions has become the primary bottleneck hindering the application of this technology. In this study, coupled low-temperature thermally treatment (<50 °C) and EA biostimulation was used to enhance PAH removal. Anoxic biodegradation of PAHs in soil was explored in microcosms in the absence and presence of added EAs at 3 temperatures (15 °C, 30 °C, and 45 °C). The influence of temperature, EA, and their interaction on the removal of PAHs were identified. A PAH degradation model based on PLSR analysis identified the importance and the positive/negative role of parameters on PAH removal. Soil archaeal and bacterial communities showed similar succession patterns, the impact of temperature was greater than that of EA. Soil microbial community and function were more influenced by temperature than EAs. Close and frequent interactions were observed among soil bacteria, archaea, PAH-degrading genes and methanogenic genes. A total of 15 bacterial OTUs, 1 PAH-degrading gene and 2 methanogenic genes were identified as keystones in the network. Coupled low-temperature thermally treatment and EA stimulation resulted in higher PAH removal efficiencies than EA stimulation alone and low-temperature thermally treatment alone.


Asunto(s)
Euryarchaeota , Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , Suelo , Temperatura , Biodegradación Ambiental , Electrones , Contaminantes del Suelo/metabolismo , Hidrocarburos Policíclicos Aromáticos/metabolismo , Archaea/metabolismo , Bacterias/metabolismo , Euryarchaeota/metabolismo , Microbiología del Suelo
9.
Environ Technol ; : 1-14, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38853645

RESUMEN

nZVI has attracted much attention in the remediation of contaminated soil and groundwater, but the application is limited due to its aggregation, poor stability, and weak migration performance. The biological CaCO3 was used as the carrier material to support nZVI and solved the nZVI agglomeration, which had the advantages of biological carbon fixation and green environmental protection. Meanwhile, the distribution of nZVI was characterised by SEM-EDS and TEM carefully. Subsequently, the dispersion stability of bare nZVI and CaCO3@nZVI composite was studied by the settlement experiment and Zeta potential. Sand column and elution experiments were conducted to study the migration performance of different materials in porous media, and the adhesion coefficient and maximum migration distances of different materials in sand columns were explored. SEM-EDS and TEM results showed that nZVI could be uniformly distributed on the surface of biological CaCO3. Compared with bare nZVI, CaCO3@nZVI composite suspension had better stability and higher absolute value of Zeta potential. The migration performance of nZVI was poor, while CaCO3@nZVI composite could penetrate the sand column and have good migration performance. What's more, the elution rates of bare nZVI and CaCO3@nZVI composite in quartz sand columns were 5.8% and 51.6%, and the maximum migration distances were 0.193 and 0.885 m, respectively. In summary, this paper studies the stability and migration performance of bare nZVI and CaCO3@nZVI composite, providing the experimental and theoretical support for the application of CaCO3@nZVI composite, which is conducive to promoting the development of green remediation functional materials.

10.
Environ Technol ; : 1-16, 2023 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-36763460

RESUMEN

The in-situ reduction of zero-valent iron (ZVI) is an effective method for removing chlorinated aliphatic hydrocarbons (CAHs) from groundwater. The heterogeneity of environmental conditions is also crucial in affecting dechlorination efficiency. Until now, the effect of Sulfate (SO42-) on ZVI activity has been debated, and the related mechanism research on SO42- behaviour during the abiotic reduction process of chlorinated alkanes is still lacking. In this study, the impacts of SO42- concentrations (0, 2, 4, 8, 80 mM) on the degradation of 1,1,2-trichloroethane (1,1,2-TCA) by micron-size ZVI (mZVI) and nano-size ZVI (nZVI) were systematically investigated. For mZVI, Kobs increased by 0.6 (2 mM), 0.5 (4 mM), 1.1 (8 mM), and 1.6 times (80 mM). For nZVI, Kobs decreased by 32% (2 mM), 39% (4 mM), 45% (8 mM), and 9% (80 mM). The results showed that SO42- increased the rate of 1,1,2-TCA degradation by mZVI but weakened the reduction performance of nZVI; however, this inhibition was reduced when the concentration reached 80 mM. SO42- controlled the degradation of 1,1,2-TCA mainly through the formation of different iron-sulfate complexes on the ZVI surface: water-soluble bidentate iron-sulfate complexes formed on the mZVI surface promoted the corrosion of the oxide layer and accelerated the reduction of 1,1,2-TCA, monodentate complexes mainly formed on the nZVI surface inhibited the reduction of 1,1,2-TCA by blocking surface sites. These results demonstrate the proof of concept to assist land managers in the field application of ZVI technology for the remediation of CAHs contaminated sites with different background concentrations of SO42-.

11.
J Hazard Mater ; 449: 130961, 2023 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-36801713

RESUMEN

Identifying the sources of pollutants and analyzing the nested structure of heavy metals is vital for the prevention and control of soil pollution. However, there is a lack of research on comparison the main sources and the nested structure at different scales. In this study, two spatial extent scales were taken as the research objects, the results showed that, (1) the point exceeding standard rate of As, Cr, Ni, and Pb is higher at the entire city scale; (2) As and Pb, while Cr, Ni, and Zn, have weaker spatial variability at the entire scale and surrounding the pollution sources, respectively; (3) the contribution of the larger structure of Cr and Ni, while Cr, Ni, and Zn, at the entire scale and surrounding the pollution sources, respectively, is bigger to the total variability. The representation of semivariogram is better when the general spatial variability is weaker and the contribution of the smaller structure is lower; (4) various factors with different influencing distance could lead to nested structure even at a small extent spatial scale. The results provide a basis for the determination of remediation and prevention objectives at different spatial scales.

12.
Pathol Res Pract ; 229: 153727, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34911016

RESUMEN

BACKGROUND: Recent studies demonstrate that long noncoding RNAs (lncRNAs) are involved in the development of various cancers. Many lncRNAs were reported to abnormally express in laryngeal squamous cell carcinoma (LSCC) and play pivotal roles in its development. LncRNA small nucleolar RNA host gene 16 (SNHG16) was previously validated as an oncogene in hepatocellular carcinoma. Nevertheless, the biological role of SNHG16 in LSCC still needs more explorations. The goal of this assay is to explore the function and molecular mechanism of lncRNA SNHG16 in the development of LSCC. METHODS AND RESULTS: First, RT-qPCR demonstrated the upregulation of SNHG16 in LSCC cells and tissues. Loss-of-function assays determined the inhibitive influence of SNHG16 downregulation on cell viability, growth, and migration in LSCC. Furthermore, SNHG16 bound with miR-140-5p in LSCC. MiR-140-5p overexpression suppressed LSCC cell proliferation and migration. NFAT5 was identified as a direct target of miR-140-5p. Through rescue experiments, overexpression of NFAT5 reversed SNHG16 knockdown-mediated suppression on cell viability, growth, and migration in LSCC. Additionally, NFAT5 overexpression activated while NFAT5 downregulation inhibited the Wnt/ß-catenin signaling pathway. CONCLUSION: LncRNA SNHG16 is upregulated in LSCC and contributes to the development of LSCC via regulating the miR-140-5p/NFAT5/Wnt/ß-catenin pathway axis. The SNHG16/miR-140-5p/NFAT5/Wnt/ß-catenin pathway axis might provide a novel strategy for LSCC treatment.


Asunto(s)
Movimiento Celular , Proliferación Celular , Neoplasias Laríngeas/patología , MicroARNs/fisiología , ARN Largo no Codificante/fisiología , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Factores de Transcripción/fisiología , Vía de Señalización Wnt/fisiología , beta Catenina/fisiología , Regulación hacia Abajo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Regulación hacia Arriba
13.
Ear Nose Throat J ; : 1455613211041788, 2021 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-34463151

RESUMEN

OBJECTIVE: To explore whether the different phases of the nasal cycle have a significant effect on nasal temperature, the nasal mucosal clearance rate, and levels of nasal nitric oxide (nNO) and to investigate the correlation between these nasal conditions. METHODS: The study participants were divided into 2 groups: the control group and the rhinitis group. The participants' nasal temperature, cilia clearance rate, and nNO levels were measured during different phases of the nasal cycle (the congestion phase and decongestion phase) in the control group and before and after undergoing inferior turbinate ablation in the rhinitis group. RESULTS: The temperature of the nasal cavity in the control group was significantly higher in the congestion phase than in the decongestion phase (P = .0025), while in the rhinitis group, the temperature of the nasal cavity decreased significantly after inferior turbinate ablation (P = .001). In the control group, the nasal mucosa clearance time was significantly shorter in the congestion phase than in the decongestion phase (P = .001), and in the rhinitis group, the clearance time of the nasal mucosa was significantly shortened after the operation (P = .0025). In the control group, the levels of nNO were significantly higher in the congestion phase than in the decongestion phase (P = .025), while in the rhinitis group, nNO levels decreased significantly after the operation (P = .005). CONCLUSION: The function of the nasal cavity changes in different phases of the nasal cycle. Therefore, when evaluating the impact of various factors on nasal function, factors associated with the nasal cycle should also be considered. Inferior turbinate plasma ablation can improve the ciliary function of the nasal mucosa, reduce the temperature of the nasal cavity, and reduce nNO levels.

14.
Huan Jing Ke Xue ; 42(3): 1123-1130, 2021 Mar 08.
Artículo en Zh | MEDLINE | ID: mdl-33742908

RESUMEN

A life cycle conceptual site model (LC-CSM) can represent the actual spatial distribution and migration of pollution of a site very accurately and be beneficial in supporting decisions for accurate site remediation or risk management. A volatile chlorinated hydrocarbon contaminated site in the Beijing-Tianjin-Hebei region was chosen as the study case. LC-CSMs were established following the site assessment, preliminary investigation, detailed investigation, and supplementary investigation of each stage. The application of field screening tests such as a membrane interface probe and the multi-electrode resistivity method assisted in identifying potential pollution sources and hot points. Concurrently, a large amount of vinyl chloride, the end product of chlorinated hydrocarbon degradation, was detected in some boreholes, indicating that pollutant biodegradation had occurred at this site. Some typical boreholes and cross-sections were chosen to analyze the biodegradation indicators and chemical fingerprints, combining the results of the comprehensive score of chlorinated hydrocarbon anaerobic biodegradability in groundwater reaching 22. It is judged that the site has strong anaerobic biodegradability. This step-by-step optimization forms an LC-CSM for site investigation, which provides scientific support for accurate site characterization.

15.
Chemosphere ; 247: 125963, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32069729

RESUMEN

Lead (Pb) pollution in the soil is becoming more and more serious, and lead poisoning incidents also constantly occur. Therefore, the remediation of lead pollution in the soil has attracted widespread attention. In this study, heavy metal lead in soil was remediated by mechanochemical methods. The effects of different ball milling conditions on the toxic leaching concentration and morphological distribution (BCR sequential extraction procedure) of lead in contaminated soil were analyzed, including the addition of calcium dihydrogen phosphate (Ca(H2PO4)2), ball milling time, and ball milling speed. The reaction mechanism was analyzed by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a laser particle size analyzer. The results show that the optimal conditions for mechanochemical immobilization were 10% additive (Ca(H2PO4)2), milling speed of 550 rpm, and ball milling time for 2 h. Under this condition, the toxic leaching concentration of lead from contaminated soil was 4.36 mg L-1, and in the BCR sequential extraction procedure, Pb was mainly present in the residual fraction (54.96%). The mechanism of mechanochemical solidification of heavy metal lead in soil is that, during the ball milling process, the lead precipitates with Ca(H2PO4)2 to produce dense agglomerates (Pb3(PO4)2 and PbxCa10-x(PO4)6(OH)2), which fixes the lead in the soil and hampers its leaching.


Asunto(s)
Fosfatos de Calcio/química , Restauración y Remediación Ambiental/métodos , Plomo/aislamiento & purificación , Contaminantes del Suelo/química , Pirofosfato de Calcio/química , Precipitación Química , Plomo/química , Metales Pesados/química , Metales Pesados/aislamiento & purificación , Microscopía Electrónica de Rastreo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/aislamiento & purificación
16.
Front Microbiol ; 10: 1804, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31440224

RESUMEN

In this study, we evaluated the effects of volatile organic compounds (VOCs) produced by Bacillus subtilis CF-3 in inhibiting Monilinia fructicola in vitro and in vivo. In the in vitro experiments, the effect of VOCs on the growth of the pathogenic fungi was explored by using plate enthalpy test; mycelial morphology was studied by scanning electron and transmission electron microscopy; and fatty acid contents in the cell membrane were assessed by gas chromatography-mass spectrometry (GC-MS). The results indicated that treatment with benzothiazole and CF-3 for 24 h, in the form of a fermentation broth (24hFB), significantly inhibited the germination of fungal spores, modified hyphal and cell morphology, and decreased the cell membrane fluidity and integrity. In the in vivo experiments, the effect of VOCs on the defense mechanism of peach fruit toward M. fructicola was studied, and we found that benzothiazole and CF-3 24hFB inhibited the activity of the pathogenic enzymes (pectinase, cellulase) secreted by M. fructicola to reduce the decomposition of plant tissues, activate the antioxidant enzymes (peroxidase, polyphenol oxidase, catalase, and superoxide dismutase) in the fruit to eliminate excessive reactive oxygen species in order to reduce plant cell damage, and trigger the disease-resistant enzymes (phenylalanine ammonia-lyase, chitinases, and ß-1,3-glucanase) to enhance the resistance of peach fruit to M. fructicola and inhibit its growth. This study suggests that CF-3 VOCs could activate disease-resistant enzymes to prevent the invasion of pathogenic fungi and induce resistance in peach, thereby providing a theoretical basis for future applications.

17.
AMB Express ; 9(1): 119, 2019 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-31352537

RESUMEN

In this study, we investigated the effects of volatile organic compounds (VOCs) produced by Bacillus subtilis CF-3 on the growth and development of Colletotrichum gloeosporioides and evaluated the elicitation of active defense responses in harvested litchi fruits. In vitro experiments were conducted to explore the bacteriostatic effect of VOCs in inhibiting pathogenic fungi by means of plate enthalpy test, scanning electron microscopy, transmission electron microscopy, and gas chromatography-mass spectrometry (GC-MS). The results showed that 2,4-di-tert-butylphenol and CF-3 24-h fermentation broth (24hFB) can significantly inhibit the germination of fungal spores, disrupt hyphal and cell morphology, and decrease cell membrane fluidity and integrity, resulting in the changes of indexes. In addition, the bacteriostasis of VOCs in the defensive ability of litchi fruits to C. gloeosporioides was studied, and it was shown that 2,4-di-tert-butylphenol and CF-3 24hFB can inhibit the activity of the pathogenic enzymes (pectinase and cellulase) secreted by C. gloeosporioides to reduce the decomposition of plant tissues, activate antioxidant enzymes (peroxidase, polyphenol oxidase, catalase, and superoxide dismutase) in the fruit to eliminate excessive reactive oxygen species in fruits in order to reduce plant cell damage and activate disease resistance enzymes (phenylalanineammonialyase, chitinases, ß-1,3-glucanase) to enhance the resistance of litchi fruits to C. gloeosporioides and inhibit its growth. This study investigated the bacteriostasis of VOCs in inhibiting C. gloeosporioides and inducing the resistance of litchi fruits, providing a theoretical basis for future applications.

18.
Front Microbiol ; 9: 456, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29593695

RESUMEN

The dynamic changes of the levels of volatile organic compounds (VOCs) produced by Bacillus subtilis CF-3 and their biocontrol effects on common fungal pathogens were researched in this study. The results showed that the VOCs in 24-h fermentation liquid (24hFL) of B. subtilis CF-3 inhibited mycelial growth of Botrytis cinerea, Colletotrichum gloeosporioides, Penicillium expansum, Monilinia fructicola, and Alternaria alternata, with a mean inhibition rate of 59.97%. The inhibitory effect on M. fructicola and C. gloeosporioides was the highest; they were therefore selected as target fungal pathogens for further experiments. Based on headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS), 74 potential VOCs were identified during the fermentation: 15 alcohols, 18 ketones, 4 pyrazines, 4 esters, 10 acids, 5 phenols, 3 hydrocarbons, 3 amines, 2 aldehydes, 5 ethers, and 5 other components. At different fermentation times, the type and content of VOCs were different. Most of the potential VOCs (62 VOCs) were identified in the 48hFL. The inhibition rates of all VOCs reached their peaks (73.46% on M. fructicola and 63.63% on C. gloeosporioides) in the 24hFL. Among the identified VOCs, 2,4-di-tert-butylphenol, 1-octanol, and benzothiazole showed significant positive correlations with the rates of M. fructicola and C. gloeosporioides inhibition. Benzoic acid and benzaldehyde showed a significant positive correlation with the rates of M. fructicola inhibition, and anisole and 3-methylbutanal showed a significant positive correlation with the rates of C. gloeosporioides inhibition. In vitro, 2,4-di-tert-butylphenol showed a strong inhibitory effect on both M. fructicola and C. gloeosporioides. In vivo, benzothiazole showed the strongest inhibitory effect on the mycelial extensions of both M. fructicola and C. gloeosporioides, which also led to an increased rate of healthy fruit. The results of the present study clarified that 2,4-di-tert-butylthiophenol and benzothiazole are key inhibitory VOCs produced by B. subtilis CF-3.

19.
Huan Jing Ke Xue ; 38(1): 368-373, 2017 Jan 08.
Artículo en Zh | MEDLINE | ID: mdl-29965068

RESUMEN

There are lots of problems in the domestic remediation of Cr (Ⅵ) contaminated soil field,such as lack of the key processing parameters,poor long-term effect and so on.The Cr (Ⅵ) heavy polluted surface soil was sampled from an electroplating site in North-China,and then treated with five different reducing reagents.At the same time,the on-line ORP probes and interval sampling test were chosen to monitor the reaction process,and to explore the reaction rate and effect.The results showed that No.4 reagent had the highest Cr (Ⅵ) reduction effect,reaching up to 99.5%,and the minimum soil Cr (Ⅵ) concentration could reach 2.4 mg·kg-1.The No.1 and No.4 reagents had relatively faster reducing rates.There were obvious difference in ORP and pH monitoring values between different reductants,for example,the No.1 reagent kept the ORP value stable at around -400 mV.The No.4 reagent gradually increased the value from -200 mV to 100 mV since 30h,and then kept stable.According to the pH difference among different reductants,the No.4 reagent was the best and kept the pH value at around 7.Taking together the final effect and process key parameters,the No.4 reagent was the best.The scale-up experiment was operated with process monitoring,and the ORP and conductivity values showed that the reduction reaction took about 160 h.This work would provide theoretical basis for controlling the maintenance condition and reaction process in soil Cr (Ⅵ) remediation.

20.
Mol Med Rep ; 14(1): 537-43, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27150436

RESUMEN

MicroRNA-23b (miR-23b) is important in tumor proliferation and metastasis. In this study, it was suggested that the levels of miR-23b were increased in nasopharyngeal carcinoma (NPC) tissues compared with the adjacent normal tissues. The present study aimed to explore the role of miR­23b upregulation in NPC. Functional studies demonstrated that inhibition of miR­23b could significantly suppress NPC cell proliferation, migration and invasion. An in vitro reporter assay suggested that E­cadherin is a direct target gene of miR­23b. Furthermore, the expression of miR­23b in NPC tissues was inversely correlated with that of E­cadherin. These findings provide evidence that miR­23b is key in promoting NPC cell proliferation, migration and invasion through targeting E­cadherin, and strongly suggests that an exogenous miR­23b inhibitor may have therapeutic value in treating NPC.


Asunto(s)
Cadherinas/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patología , Interferencia de ARN , Regiones no Traducidas 3' , Adulto , Anciano , Sitios de Unión , Carcinoma , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular , Femenino , Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Metástasis de la Neoplasia , Estadificación de Neoplasias
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