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1.
Inorg Chem ; 62(3): 1234-1239, 2023 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-36622743

RESUMEN

Dielectric capacitors have become an important component in current pulsed power devices and thus have attracted great research interest in recent years. Among all kinds of dielectric materials, the bismuth ferrite (BiFeO3)-based ceramic capacitors show possible applications in dielectric energy storage because of their large polarization. However, the relatively high conductivity badly limits the improvement of electric breakdown strength, thus leading to low energy density. Herein, the perovskite end-member La(Mg2/3Nb1/3)O3 and sintering aid MnO2 were simultaneously introduced into BiFeO3-SrTiO3 solid solutions to improve the relaxation features and electric breakdown strength. Accordingly, a high recoverable energy density of 6.3 J/cm3 and an acceptable efficiency of 74.3% were realized under 450 kV/cm. In addition, the good frequency/thermal stability and superior charge-discharge performances were also realized. This work provides feasible approaches to modify the capacitive energy storage of BiFeO3-based relaxor ferroelectric ceramics.

2.
Bull Environ Contam Toxicol ; 104(2): 166-172, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31865410

RESUMEN

This study was performed to evaluate the microplastics (MPs) pollution of sediments from River Yongfeng. It was observed that the MPs in sediments were present with contents of 0.5-16.75 mg/kg and abundances of 5-72 items/kg, coupled by variation coefficients of 109% and 91%, respectively, indicating that the distribution of MPs had high spatial variation. The land-based source of business zone is thought to be the significant contributor to accumulation of MPs in those sites with high quantity of MPs. Film was the predominant shape of MPs in river sediments followed by the line and fragment ones. Meanwhile, the MPs detected were mainly composed by four types including Polypropylene (24%), Polyethylene (61%), Polyethylene Terephthalate (8%) and Polystyrene (7%) based on number fraction, respectively, which indicates that Polypropylene and Polyethylene were the major types of MPs in the sediments. Size fraction performance suggests that those MPs < 1000 µm were of ubiquitous presence. The weathering of fringes was universally observed regardless of varying surface among MPs. Despite digestion with oxidative acid solution and subsequent washing by distilled water unexpected elements can still be detected, which should be considered as determining the materials associated.


Asunto(s)
Monitoreo del Ambiente , Microplásticos/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , China , Ciudades , Contaminación Ambiental/análisis , Microplásticos/clasificación
3.
Opt Lett ; 44(4): 983-986, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30768041

RESUMEN

Solution-processed white organic light-emitting diodes (WOLEDs) with silica-coated silver nanocubes (Ag@SiO2 NCs) incorporated at the interface of a hole transporting layer and emission layer are studied. The concentration of Ag@SiO2 NCs is varied to investigate the effect of Ag@SiO2 NCs on the performances of WOLEDs. Owing to the sharp edges and corners, Ag NCs greatly improve the radiative rate and emission intensity of nearby blue excitons. The blue emission at different Ag@SiO2 NC concentrations determines the performance of the WOLEDs. The emission of the orange excitons is strengthened by the high concentration of Ag@SiO2 NCs, which slightly influences the device performance. On the other hand, the SiO2 shell and some SiO2 nanospheres coexisting with Ag NCs reduce the hole transporting, improving the carrier balance in the WOLEDs. The experimental and simulated results also show that excessive Ag@SiO2 NCs may cause a rough film surface, unbalanced carrier injection, and fluorescence quenching, which decreases the device performance. The optimized WOLED with a proper concentration of Ag@SiO2 NCs has a peak current efficiency of 53.9 cd/A, acquiring a significant enhancement factor of 77.3% compared to the control device without Ag@SiO2 NCs.

4.
Environ Geochem Health ; 41(6): 2697-2708, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31140134

RESUMEN

Road-deposited sediment (RDS) has been identified as both the source and sink of various pollutants. In this study, the highway-deposited sediment (HDS) in Spring, Summer, Autumn and Winter was characterized. On average, the mass proportions of particles with the size of 830-4750 µm, 500-830 µm, 250-500 µm, 150-250 µm, 63-150 µm and < 63 µm were 23.6 ± 8.6%, 16.9 ± 3.4%, 28.4 ± 3.5%, 10.0 ± 4.3%, 15.7 ± 5.8% and 5.3 ± 2.0%, respectively, wherein the HDS of 63-830 µm accounted for 71% of the total mass load. It was observed that the particle size distribution of HDS could be described using the gamma distribution function based on gravimetric and cumulative basis (R2 (determination coefficient) = 0.9960-0.9995). The bulk pollutant contents of HDS showed seasonal variation with the mean of COD (chemical oxygen demand), nitrogen, phosphorus, Zn (zinc), Pb (lead) and Cd (cadmium) as 57 g/kg, 839 mg/kg, 97 mg/kg, 627 mg/kg, 110 mg/kg and 1.00 mg/kg and the highest COD of 83 g/kg in Autumn, nitrogen 1164 mg/kg Autumn, phosphorus 133 mg/kg Winter, Zn 801 mg/kg Summer, Pb 133 mg/kg Spring and the highest Cd of 1.36 mg/kg in Summer, respectively. The contents of Zn, Pb and Cd in HDS were significantly above their local soil background values. Moreover, the size fractional pollutant contents overall increased as particles' size increased. Averagely, 40-52% pollutant loads were associated with the particles < 250 µm, which can be moved easily by runoff. This study suggests that the behaviors of HDS different from city RDS should be considered as nonpoint source pollution control is performed.


Asunto(s)
Contaminantes Ambientales/análisis , Sedimentos Geológicos/análisis , Análisis de la Demanda Biológica de Oxígeno , China , Ciudades , Monitoreo del Ambiente , Contaminantes Ambientales/química , Sedimentos Geológicos/química , Nitrógeno/análisis , Tamaño de la Partícula , Fósforo/análisis , Estaciones del Año
5.
Bull Environ Contam Toxicol ; 101(5): 664-671, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30317382

RESUMEN

A simple, practical and precise method for the simultaneous analysis of 32 different polycyclic aromatic hydrocarbon (PAHs) including 16 parent PAHs, 8 oxygenated-PAHs (oxy-PAHs), 4 chloro-PAHs, and 4 nitrogen-containing heterocyclic PACs (N-PACs), in groundwater was established via gas chromatography-mass spectrometry (GC-MS) combined with liquid-liquid extraction (LLE). The obtained detection method possesses instrument detection limits (at a signal to noise of 3:1) in the range of 0.05-10 ng/mL and method detection limits in the range of 1.7-13.2 ng/L. The average recoveries of the 32 analytes were in the range of 54.3%-127.0% with relative standard deviations (RSDs) < 20%, and the recoveries of 16 PAH derivatives ranged from 54.3 to 115.1% with RSDs < 17.9%. The method has been successfully applied to the screening of 64 groundwater samples from eastern China. The results revealed that 30 types of targets including 16 PAHs and 14 PAH derivatives were detected and that the groundwater in most areas is slightly polluted, while the pollution of Jiangsu Province and Shandong Province was more serious.


Asunto(s)
Contaminantes Ambientales/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Hidrocarburos Policíclicos Aromáticos/análisis , China , Agua Subterránea/análisis , Límite de Detección , Extracción Líquido-Líquido
6.
Pak J Pharm Sci ; 29(5): 1591-1600, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27731817

RESUMEN

GC-MS is the basis of analysis of plant volatiles. Several protocols employed for the assay have resulted in inconsistent results in the literature. We developed a GC-MS method, which were applied to analyze 25 volatiles (α-pinene, camphene, ß-pinene, 2-methyl-2-pentenal, myrcene, (+)-limonene, eucalyptol, trans-2-hexenal, γ-terpinene, cis-3-hexeneyl-acetate, 1-hexanol, α-pinene oxide, cis-3-hexen-1-ol, trans-2-hexen-1-ol, decanal, linalool, acetyl-borneol, ß-caryophyllene, 2-undecanone, 4-terpineol, borneol, decanol, eugenol, isophytol and phytol) of Houttuynia cordata Thunb. Linear behaviors for all analytes were observed with a linear regression relationship (r2>0.9991) at the concentrations tested. Recoveries of the 25 analytes were 98.56-103.77% with RSDs <3.0%. Solution extraction (SE), which involved addition of an internal standard, could avoid errors for factors in sample preparation by steam distillation (SD) and solidphase micro extraction (SPME). Less sample material (≍0.05g fresh leaves of H. cordata) could be used to determine the contents of 25 analytes by our proposed method and, after collection, did not affect the normal physiological activity or growth of H. cordata. This method can be used to monitor the metabolic accumulation of H. cordata volatiles.


Asunto(s)
Cromatografía de Gases y Espectrometría de Masas , Houttuynia/química , Extractos Vegetales/aislamiento & purificación , Compuestos Orgánicos Volátiles/aislamiento & purificación , Calibración , Cromatografía de Gases y Espectrometría de Masas/normas , Modelos Lineales , Fitoterapia , Hojas de la Planta , Plantas Medicinales , Estándares de Referencia , Reproducibilidad de los Resultados
7.
Appl Opt ; 54(4): 934-9, 2015 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-25967808

RESUMEN

A gray change detection method has been proposed to monitor damage in materials. The normalized parameter C has been defined by the displacement and the gray level value, which can reflect the gray change of each pixel point in the region of interest of the image. A zero deformation experiment has been done to discuss the feature of gray change caused by many factors except the damage. The results show that local expanded regions with concentrations of C can be considered as the damage regions. The uniaxial tensile experiments for an artificial rock specimen and a polycarbonate specimen have been done to verify the performance of the proposed method. The results show that the proposed method is effective for monitoring surface cracks in rocks and the shear band in polymers. This work provides a useful method for damage monitoring in materials.

8.
Zhongguo Zhong Yao Za Zhi ; 40(8): 1444-52, 2015 Apr.
Artículo en Zh | MEDLINE | ID: mdl-26281577

RESUMEN

The relationship of nutrients and microorganisms in soils with polyphenols and total flavonoids of Houttuynia cordata were investigated by measuring nutrients, enzyme activity, pH, concentrations of microbe phospholipid fatty acids (PLFAs) in soils, and determining concentrations of polyphenols and total flavonoids of H. cordata. The research is aimed to understand characteristics of the planting soils and improve the quality of cultivated H. cordata. The soils at different sample sites varied greatly in nutrients, enzyme activity, pH, microbic PLFAs and polyphenols and all flavonoids. The content of total PLFAs in sample sites was following: bacteria > fungi > actinomyces > nematode. The content of bacteria PLFAs was 37.5%-65.0% at different sample sites. Activities of polyphenol oxidease, concentrations of available P and content of PLFAs of bacteria, actinomyces and total microorganisms in soils were significantly and positively related to the concentrations of polyphenols and total flavonoids of H. cordata, respectively (P < 0.05) . The Content of fungi PLFAs in soils was significantly and negatively related to concentrations of polyphenols and total flavonoids of H. cordata, respectively (P < 0.05). This study provides evidence that effectiveness of the soil nutrient, which may be improved due to transformation of soil microorganisms and enzymes to N and P in the soils, was beneficial to adaptation of H. cordata adapted to different soil conditions, and significantly affects metabolic accumulation of polyphenols and flavonoids of H. cordata.


Asunto(s)
Medicamentos Herbarios Chinos/análisis , Flavonoides/análisis , Houttuynia/química , Polifenoles/análisis , Suelo/química , Bacterias/metabolismo , Medicamentos Herbarios Chinos/metabolismo , Ácidos Grasos/metabolismo , Flavonoides/metabolismo , Hongos/metabolismo , Houttuynia/metabolismo , Houttuynia/microbiología , Fosfolípidos/metabolismo , Polifenoles/metabolismo , Microbiología del Suelo
9.
Pak J Pharm Sci ; 27(2): 223-31, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24577906

RESUMEN

A new, validated method, developed for the simultaneous determination of 16 phenolics (chlorogenic acid, scopoletin, vitexin, rutin, afzelin, isoquercitrin, narirutin, kaempferitrin, quercitrin, quercetin, kaempferol, chrysosplenol D, vitexicarpin, 5-hydroxy-3,3',4',7-tetramethoxy flavonoids, 5-hydroxy-3,4',6,7-tetramethoxy flavonoids and kaempferol-3,7,4'-trimethyl ether) in Houttuynia cordata Thunb. was successfully applied to 35 batches of samples collected from different regions or at different times and their total antioxidant activities (TAAs) were investigated. The aim was to develop a quality control method to simultaneously determine the major active components in H. cordata. The HPLC-DAD method was performed using a reverse-phase C18 column with a gradient elution system (acetonitrile-methanol-water) and simultaneous detection at 345 nm. Linear behaviors of method for all the analytes were observed with linear regression relationship (r(2)>0.999) at the concentration ranges investigated. The recoveries of the 16 phenolics ranged from 98.93% to 101.26%. The samples analyzed were differentiated and classified based on the contents of the 16 characteristic compounds and the TAA using hierarchical clustering analysis (HCA) and principal component analysis (PCA). The results analyzed showed that similar chemical profiles and TAAs were divided into the same group. There was some evidence that active compounds, although they varied significantly, may possess uniform anti-oxidant activities and have potentially synergistic effects.


Asunto(s)
Houttuynia/química , Antioxidantes/análisis , Compuestos de Bifenilo/química , Cromatografía Líquida de Alta Presión , Análisis por Conglomerados , Flavonoides/análisis , Indicadores y Reactivos , Fenoles/análisis , Picratos/química , Análisis de Componente Principal , Control de Calidad , Estándares de Referencia , Análisis de Regresión , Reproducibilidad de los Resultados , Soluciones , Solventes , Espectrofotometría Ultravioleta/métodos
10.
J Agric Food Chem ; 72(21): 12057-12071, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38753758

RESUMEN

Plant growth-promoting endophytes (PGPE) can effectively regulate plant growth and metabolism. The regulation is modulated by metabolic signals, and the resulting metabolites can have considerable effects on the plant yield and quality. Here, tissue culture Houttuynia cordata Thunb., was inoculated with Rhizobium sp. (BH46) to determine the effect of BH46 on H. cordata growth and metabolism, and elucidate associated regulatory mechanisms. The results revealed that BH46 metabolized indole-3-acetic acid and induced 1-aminocyclopropane-1-carboxylate deaminase to decrease ethylene metabolism. Host peroxidase synthesis MPK3/MPK6 genes were significantly downregulated, whereas eight genes associated with auxins, cytokinins, abscisic acid, jasmonic acid, and antioxidant enzymes were significantly upregulated. Eight genes associated with flavonoid biosynthesis were significantly upregulated, with the CPY75B1 gene regulating the production of rutin and quercitrin and the HCT gene directly regulating the production of chlorogenic acid. Therefore, BH46 influences metabolic signals in H. cordata to modulate its growth and metabolism, in turn, enhancing yield and quality of H. cordata.


Asunto(s)
Endófitos , Houttuynia , Proteínas de Plantas , Houttuynia/microbiología , Houttuynia/metabolismo , Houttuynia/genética , Endófitos/metabolismo , Endófitos/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , Reguladores del Crecimiento de las Plantas/metabolismo , Reguladores del Crecimiento de las Plantas/farmacología , Ácidos Indolacéticos/metabolismo , Rhizobium/genética , Rhizobium/metabolismo , Flavonoides/metabolismo , Ácido Abscísico/metabolismo , Etilenos/metabolismo , Liasas de Carbono-Carbono/metabolismo , Liasas de Carbono-Carbono/genética
11.
Toxics ; 11(8)2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37624168

RESUMEN

Tea is a non-alcoholic beverage popular among Chinese people. However, due to the application of chemical and organic fertilizers in the tea planting process, the environment pollutionaround the tea plantation, and the instruments used in the processing, heavy metal elements will accumulate in the tea, which brings health risks for tea consumers. This study summarized heavy metal concentrations from 227 published papers and investigated the current contamination status of tea and tea plantation soils, and, finally, the risk of heavy metal exposure to tea consumers in China is assessed, in terms of both non-carcinogenic and carcinogenic risk. The average contamination of six heavy metals in tea-arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), and lead (Pb)-were 0.21, 0.14, 1.17, 14.6, 0.04, and 1.09 mg/kg, respectively. The areas with high concentrations of heavy metals in tea were concentrated primarily in southwest China, some areas in eastern China, and Shaanxi Province in northwest China. The non-carcinogenic risks of heavy metals in tea are all within safe limits. The national average HI value was 0.04, with the highest HI value of 0.18 in Tibet, which has the largest tea consumption in China. However, the carcinogenic risks of Cd in Shaanxi Province, Anhui Province, and southwest China exceed the acceptable range, and due attention should be given to these areas.

12.
Heliyon ; 9(6): e17045, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37484330

RESUMEN

The potential to create new ecosystems in rivers is possible through the use of reclaimed water as a replenishment source, although the long-term effects of this method are unknown. In this study, the water quality and aquatic ecological evolution of a newly constructed river replenished by reclaimed water in Beijing (the Jing River) were investigated, and the conventional water quality, phytoplankton indicators, and submerged plant growth conditions from October 2018 to December 2020 were analyzed. Spearman's correlation and redundancy analysis between possible influential environmental factors and algal indicators were conducted. The results show that the major water quality indicators could meet the water quality standards for landscape water. There were seven phyla present, including 322 species of phytoplankton. The phytoplankton density increased, followed by a decreasing trend. Phytoplankton densities at each monitoring site reached 10 × 106 to 25 × 106 cells/L in 2019 before decreasing in 2020, then ranging from 8 × 106 to 20 × 106 cells/L. Phytoplankton growth was influenced by changing water quality and ecosystems. Consequently, the submerged plant coverage rate gradually increased from 2018 (0%) to 2020 (26.27%-37.06%), as did biodiversity. Through the implementation of ecological restoration measures in the Jing River, the reclaimed water environment evolved into a more natural water environment, which could provide some reference for similar areas to use reclaimed water as a water replenishment source.

13.
Front Microbiol ; 14: 1218474, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37876787

RESUMEN

The microorganisms associated with a plant influence its growth and fitness. These microorganisms accumulate on the aerial and root surfaces of plants, as well as within the plants, as endophytes, although how the interaction between microorganisms protects the plant from pathogens is still little understood. In the current study, the impact of assembled the bacterial communities against the pathogenic fungus to promote Artemisia annua L. growths was investigated. We established a model of bacterium-fungus-plant system. Eight bacterial strains and a fungal pathogen Globisporangium ultimum (Glo) were isolated from wild A. annua roots and leaves, respectively. We assembled the six-bacteria community (C6: Rhizobium pusense, Paracoccus sp., Flavobacterium sp., Brevundimonas sp., Stenotrophomonas sp., and Bacillus sp.) with inhibition, and eight-bacteria community (C8) composing of C6 plus another two bacteria (Brevibacillus nitrificans and Cupriavidus sp.) without inhibition against Glo in individually dual culture assays. Inoculation of seedlings with C8 significantly reduced impact of Glo. The growth and disease suppression of A. annua seedlings inoculated with C8 + Glo were significantly better than those of seedlings inoculated with only Glo. C8 had more inhibitory effects on Glo, and also enhanced the contents of four metabolites in seedling roots compared to Glo treatment only. Additionally, the inhibitory effects of root extracts from A. annua seedlings showed that Glo was most sensitive, the degree of eight bacteria sensitivity were various with different concentrations. Our findings suggested that the non-inhibitory bacteria played a vital role in the bacterial community composition and that some bacterial taxa were associated with disease suppression. The construction of a defined assembled bacterial community could be used as a biological fungicide, promoting biological disease control of plants.

14.
Zhongguo Zhong Yao Za Zhi ; 37(23): 3577-80, 2012 Dec.
Artículo en Zh | MEDLINE | ID: mdl-23477143

RESUMEN

OBJECTIVE: To study the chemical constituents and bacteriostatic activity of Psammosilene tunicoides. METHOD: Such methods as silica gel column chromatography and gel column chromatography were adotped separate and purify the compounds, and their structures were indentified on the basis of their spectral data and physicochemical properties. RESULT: Ten compounds were separated from ethanol extracts and identified as methyl-4-hydroxybenzoate (1), N-methylsaccharin (2), 3-hydroxy-4-methoxybenzoic acid (3), germanicol (4), tricosanoic acid (5), octacosane (6), amber acid (7), succinic acid (8), stellarine A (9), and oleanane-12-ene-3alpha, 16alpha-two hydroxy-23,28-acid (10). CONCLUSION: All compounds except compound 10 were separated from P. tunicoides for the first time. Compounds 8 and 9 showed the bacteriostatic activity to a certain extent.


Asunto(s)
Antibacterianos/química , Caryophyllaceae/química , Medicamentos Herbarios Chinos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Medicamentos Herbarios Chinos/aislamiento & purificación , Medicamentos Herbarios Chinos/farmacología
15.
Artículo en Inglés | MEDLINE | ID: mdl-35742459

RESUMEN

In this study, the occurrence, distribution, and ecological risk of 40 commonly used antibiotics, including 15 sulfonamides (SAs), 9 fluoroquinolones (FQs), 7 macrolides (MCs), 3 tetracyclines (TCs), 2 chloramphenicols (CAPs), and 4 other categories, in the aquatic environment of the karst plateau wetland Caohai of the Yangtze River basin in southwestern China are reported. In total, 27 antibiotics were detected, with the detection rate ranging from 5% to 100%. The total concentration at each site ranged from 21.8 ng/L to 954 ng/L, with the average concentration being 189 ng/L. FQs and MCs were the most predominant categories, contributing 29.3% and 25.0% of the total antibiotic burden. The five most commonly detected antibiotics were ciprofloxacin (CIP), oxytetracycline (OTC), acetyl sulfamethoxazole (ASMZ), norfloxacin (NOR), and florfenicol (FF). The spatial distribution of the total concentration at each site demonstrated a decreasing trend from the southeastern area upstream adjoining the main counties to the northwestern area downstream, indicating that human activities have a great impact. Meanwhile, the natural attenuation rates of different types of antibiotics in the direction of flow ranged from 17.6% to 100%, which implied the natural purification potential of the wetland for antibiotics. The cluster analysis results indicated that domestic sewage and wastewater from agriculture and animal husbandry were the main sources of contamination in the surrounding wetland. Risk quotients (RQs) assessment showed that most of the individuals were at low to medium risk and that the adverse risks posed by mixtures of antibiotics were higher than those posed by the individual antibiotics.


Asunto(s)
Antibacterianos , Contaminantes Químicos del Agua , Animales , Antibacterianos/análisis , China , Monitoreo del Ambiente/métodos , Fluoroquinolonas , Medición de Riesgo , Contaminantes Químicos del Agua/análisis , Humedales
16.
ACS Appl Mater Interfaces ; 14(39): 44539-44549, 2022 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-36150016

RESUMEN

Owing to the merits of giant power density and ultrafast charge-discharge time, dielectric capacitors including ceramics and films have inspired increasing interest lately. Nevertheless, the energy storage density of dielectric ceramics should be further optimized to cater to the boosting demand for the compact and portable electronic devices. Herein, an ultrahigh recoverable energy storage density Wrec of 13.44 J/cm3 and a high efficiency η of 90.14% are simultaneously realized in BiFeO3-BaTiO3-NaTaO3 relaxor ferroelectric ceramics with high polarization Pmax, reduced remanent polarization Pr, and optimized electric breakdown strength Eb. High Pmax originates from the genes of BiFeO3-based ceramics, and reduced Pr is induced by enhanced relaxor behavior. Particularly, a large Eb is achieved by the synergic contributions from complicated internal and external factors, such as decreased grain size and improved resistivity and electrical homogeneity. Furthermore, the ceramics also exhibit satisfactory frequency, cycling and thermal reliability, and decent charge-discharge property. This work not only indicates that the BiFeO3-based relaxor ferroelectric materials are promising choices for the next-generation electrostatic capacitors but also paves a potential approach to exploit novel high-performance dielectric ceramics.

17.
J Hazard Mater ; 418: 126134, 2021 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-34119975

RESUMEN

The dietary lead (Pb) risk across China was assessed based on the margin of exposure (MOE) approach by comparing the level (1.5 µg/kg/d) based on the Pb concentrations in foodstuffs from1386 published articles. The Pb averages of the 18 foods were lower than their corresponding limits enacted by the Chinese government, ranging from 0.09 to 0.30 mg/kg. Food from plants had a much higher contribution to dietary Pb intake than that from animals (86% vs. 14%), and cereals and vegetables contributed 79% of the Pb intake from plant-based food. Although each category of food contained a relatively low Pb concentration, the accumulated Pb from the total diet posed a high risk to human health. The MOE risk from dietary Pb averaged 1.57 and ranged from 0.13 to 6.18, with high risks in southern, southwestern, eastern, central, and northern China. The MOE risk from Pb could be decreased by adjusting the dietary structure, and the ratio of people categorized as high risk (MOE < 1) would decrease from 56% to 37%, 41%, or 24% if the category of cereal or vegetable or both cereals and vegetables with the lowest Pb concentration in their local areas were selected, respectively.


Asunto(s)
Contaminación de Alimentos , Plomo , Animales , China , Contaminación de Alimentos/análisis , Humanos , Plomo/toxicidad , Medición de Riesgo , Verduras
18.
Huan Jing Ke Xue ; 42(1): 166-174, 2021 Jan 08.
Artículo en Zh | MEDLINE | ID: mdl-33372468

RESUMEN

The concentrations of 22 endocrine disrupting chemicals, including 4 categories of sex hormones, progesterones, glucocorticoids, and phenolic hormones, in groundwater of Wuxi-Changzhou were analyzed using solid-phase extraction and ultra-performance liquid chromatography tandem mass spectrometry. The results indicated that 20 EDCs were detected, among which bisphenol A (BPA), estrone (E1), estradiol (E2), and 17α-ethinyl estradiol (EE2) were the main components with detection ratios greater than 90%, followed by estriol (E3) and methyl-prednisolonel (Meprednl), which had detection rates 67.7% and 48.4%, respectively. The average concentration of BPA was the highest (4.95 ng·L-1), followed by that of Meprednl, E2, prednisolone (Prednl), testosterone propionate (TES-pro), and megestrol-acetate (MA; 2.84, 0.71, 0.64, 0.58, and 0.53 ng·L-1, respectively). The total concentration in each site ranged from 0.38 to 147.35 ng·L-1. The sites with higher concentration were mainly distributed in the Xinbei District, Liyang City, and the Zhonglou District of Changzhou City. The potential sources were analyzed by a principal component analysis (PCA) combining the point sources near sample sites. The results showed that domestic sewage, aquaculture, and industrial wastewater were the main sources, following by medical wastewater. A non-carcinogenic risk assessment showed a low risk of EDCs in the groundwater of the study area, and the risk of drinking water was greater than that of skin exposure. EE2 had the highest non-carcinogenic risk and is suggested to be monitored in priority.


Asunto(s)
Disruptores Endocrinos , Agua Subterránea , Contaminantes Químicos del Agua , Disruptores Endocrinos/análisis , Monitoreo del Ambiente , Estradiol/análisis , Estrona/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis
19.
Pol J Microbiol ; 70(3): 359-372, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34584530

RESUMEN

Latent pathogenic fungi (LPFs) affect plant growth, but some of them may stably colonize plants. LPFs were isolated from healthy Houttuynia cordata rhizomes to reveal this mechanism and identified as Ilyonectria liriodendri, an unidentified fungal sp., and Penicillium citrinum. Sterile H. cordata seedlings were cultivated in sterile or non-sterile soils and inoculated with the LPFs, followed by the plants' analysis. The in vitro antifungal activity of H. cordata rhizome crude extracts on LPF were determined. The effect of inoculation of sterile seedlings by LPFs on the concentrations of rhizome phenolics was evaluated. The rates of in vitro growth inhibition amongst LPFs were determined. The LPFs had a strong negative effect on H. cordata in sterile soil; microbiota in non-sterile soil eliminated such influence. There was an interactive inhibition among LPFs; the secondary metabolites also regulated their colonization in H. cordata rhizomes. LPFs changed the accumulation of phenolics in H. cordata. The results provide that colonization of LPFs in rhizomes was regulated by the colonizing microbiota of H. cordata, the secondary metabolites in the H. cordata rhizomes, and the mutual inhibition and competition between the different latent pathogens.


Asunto(s)
Hongos , Houttuynia , Interacciones Microbianas , Extractos Vegetales , Plantas Medicinales , Rizoma , Hongos/efectos de los fármacos , Houttuynia/microbiología , Interacciones Microbianas/fisiología , Extractos Vegetales/farmacología , Plantas Medicinales/microbiología , Rizoma/química , Rizoma/microbiología , Microbiología del Suelo
20.
Plant Signal Behav ; 16(9): 1929731, 2021 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-34092178

RESUMEN

Endophytic fungi usually establish a symbiotic relationship with the host plant and affect its growth. In order to evaluate the impact of endophytic fungi on the Chinese herbal medicinal plant Houttuynia cordata Thunb., three endophytes isolated from the rhizomes of H. cordata, namely Ilyonectria liriodendra (IL), unidentified fungal sp. (UF), and Penicillium citrinum (PC), were co-cultured individually with H. cordata in sterile soil for 60 days. Analysis of the results showed that the endophytes stimulated the host plant in different ways: IL increased the growth of rhizomes and the accumulation of most of the phenolics and volatiles, UF promoted the accumulation of the medicinal compounds afzelin, decanal, 2-undecanone, and borneol without influencing host plant growth, and PC increased the fresh weight, total leaf area and height of the plants, as well as the growth of the rhizomes, but had only a small effect on the concentration of major secondary metabolites. Our results proved that the endophytic fungi had potential practical value in terms of the production of Chinese herbal medicines, having the ability to improve the yield and accumulation of medicinal metabolites.


Asunto(s)
Endófitos/metabolismo , Houttuynia/química , Houttuynia/crecimiento & desarrollo , Houttuynia/microbiología , Rizoma/crecimiento & desarrollo , Rizoma/metabolismo , Rizoma/microbiología , Hypocreales/metabolismo , Penicillium/metabolismo , Extractos Vegetales/química , Extractos Vegetales/metabolismo , Plantas Medicinales/química , Plantas Medicinales/crecimiento & desarrollo , Plantas Medicinales/microbiología , Simbiosis
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