Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Environ Manage ; 345: 118584, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37423187

RESUMO

Mulching and biochar are increasingly used individually in agriculture, but little is known about their combined effects on N2O distribution and dispersion in ridge and furrow profiles. We conducted a 2-year field experiment in northern China to determine soil N2O concentrations using the in situ gas well technique and calculate N2O fluxes from ridge and furrow profiles by the concentration gradient method. The results showed that mulch and biochar increased soil temperature and moisture and altered the mineral nitrogen status, leading to a decrease in the relative abundance of nitrification genes in the furrow area and an increase in the relative abundance of denitrification genes, with denitrification remaining as the main source of N2O production. N2O concentrations in the soil profile increased significantly after fertiliser application, and N2O concentrations in the ridge area of the mulch treatment were much higher than those in the furrow area, where vertical and horizontal diffusion occurred. Biochar addition was effective in reducing N2O concentrations but had no effect on the N2O distribution and diffusion pattern. Soil temperature and moisture, but not soil mineral nitrogen, explained the variation in soil N2O fluxes during the non-fertiliser application period. Compared to furrow-ridge planting (RF), furrow-ridge mulch planting (RFFM), furrow-ridge planting with biochar (RBRF) and furrow-ridge mulch planting with biochar (RFRB) resulted in 9.2%, 11.8% and 20.8% increases in yield per unit area and 1.9%, 26.3% and 27.4% decreases in N2O fluxes per unit of yield, respectively. The interaction between mulching and biochar significantly affected the N2O fluxes per unit of yield. Biochar costs aside, RFRB is very promising for increasing alfalfa yields and reducing N2O fluxes per unit of yield.


Assuntos
Agricultura , Solo , Agricultura/métodos , Carvão Vegetal , China , Fertilizantes , Nitrogênio , Óxido Nitroso
2.
Huan Jing Ke Xue ; 44(7): 4162-4169, 2023 Jul 08.
Artigo em Zh | MEDLINE | ID: mdl-37438313

RESUMO

Biochar is widely used in agricultural production practices as a soil conditioner that can be used both alone and jointly with chemical fertilizer. However, there are few studies on the effects of the combined application of biochar and phosphate fertilizer with different particle sizes on soil and plants. In this experiment, pot experiments were used to study the effects of biochar with different particle sizes on soil nutrients, enzyme activity, and Alfalfa nutrient absorption under two phosphorus levels (according to diameter, the biochar was divided into C1:>1 mm and C2:<0.01 mm). This study showed that the combined application of biochar and phosphorus significantly improved soil nutrients, enzyme activity, and Alfalfa nutrient absorption. Among them, the C2 treatment significantly increased the soil available phosphorus content and phosphatase activity (P<0.05), whereas the C1 treatment had a significant effect on ammonium nitrogen, nitrate nitrogen, urease, and catalase activities (P<0.05). Moreover, the differences in nutrients and enzymes among biochar treatments with different particle sizes were affected by soil phosphorus levels. At the P0 level, there was no significant difference in ammonium nitrogen and nitrate nitrogen contents between the C1 and C2 treatments. At the P1 level, the contents of NH4+-N and NO3--N in the C1 treatment were 24.19% and 18.68% higher than those in the C2 treatment (P<0.05), but there was no significant difference between the C1 and C2 treatments. Phosphorus addition significantly increased the N and P contents of Alfalfa above ground and in the ground (P<0.05), but there was no significant effect on the nutrient content of Alfalfa between different particle sizes of biochar. In conclusion, biochar and phosphate fertilizer can be used as an effective means of soil improvement. In addition, when using biochar for soil improvement, the impact of particle size on soil nutrients and soil enzymes should be considered.


Assuntos
Fósforo , Solo , Fertilizantes , Medicago sativa , Nitratos , Fosfatos , Nitrogênio , Nutrientes
3.
J Colloid Interface Sci ; 633: 640-648, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36473354

RESUMO

Constructing transitionmetalsulfides (TMSs) heterostructure is an effective strategy to optimize the catalytic performance for hydrogen evolution reaction (HER) in alkaline medium. Herein, the rhombohedral nickel sulfide/hexagonal nickel sulfide (r-NiS/h-NiS) catalysts with the NiS phase-heterostructure were successfully fabricated by a simple one pot method. The r-NiS/h-NiS (1.25) (1.25 means the theoretical mole ratio of S and Ni added to reaction) displayed the excellent HER performance with low overpotential (101 ± 1 mV@10 mA cm-2) and small Tafel slope (62.10 ± 0.1 mV dec-1), which were superior to the pure phase r-NiS and h-NiS. In this work, the improved HER catalytic performances were attributed to the dense coupling interfaces between the r-NiS and h-NiS. This work shows the feasibility of construction NiS phase-heterostructure and provides a novel strategy for the application of NiS for water splitting.


Assuntos
Hidrogênio , Água , Catálise
4.
J Food Sci ; 87(3): 886-894, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35142373

RESUMO

ß-Glucosidase is a key enzyme that hydrolyzes nonvolatile glycosylated precursors of aroma compounds and enhances the organoleptic quality of wines. In this study, a novel ß-glucosidase from Hanseniaspora uvarum Yun268 was localized, purified, and characterized. Results indicated that ß-glucosidase activity was mainly distributed within the cells. After purification via ammonium sulfate precipitation combined with chromatography, ß-glucosidase specific activity increased 8.36 times, and the activity recovery was 56.90%. The enzyme had a molecular mass of 74.22 kDa. It has a Michaelis constant (Km ) of 0.65 mmol/L, and a maximum velocity (Vmax ) of 5.1 nmol/min under optimum conditions; and Km of 0.94 mmol/L, and Vmax of 2.8 nmol/min under typical winemaking conditions. It exhibited the highest activity at 50°C and pH 5.0 and was stable at a temperature range of 20-80°C and pH range of 3.0-8.0. The enzyme has good tolerance to Fe3+ , especially maintaining 93.68% of its activity with 10 mmol/L of Fe3+ . Ethanol (<20%) and glucose (<150 g/L) inhibited its activity only slightly. Therefore, ß-glucosidase from H. uvarum Yun268 has excellent biochemical properties and a good application potential in winemaking. PRACTICAL APPLICATION: Winemaking is a biotechnological process in which exogenous ß-glucosidase is used to overcome the deficiency of endogenous ß-glucosidase activity in grapes. By localizing, purifying, and characterizing of ß-glucosidase from Hanseniaspora uvarum Yun268, it is expected to reveal its physical and chemical characteristics to evaluate its oenological properties in winemaking. The results may provide the basis for promoting the release of varietal aroma and improving wine sensory quality in the wine industry.


Assuntos
Hanseniaspora , Vinho , Fermentação , Odorantes/análise , Vinho/análise , beta-Glucosidase/metabolismo
5.
Front Psychiatry ; 11: 608928, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33324267

RESUMO

Empathy refers to the ability to understand someone else's emotions and fluctuates with the current state in healthy individuals. However, little is known about the neural network of empathy in clinical populations at different pain states. The current study aimed to examine the effects of long-term pain on empathy-related networks and whether empathy varied at different pain states by studying primary dysmenorrhea (PDM) patients. Multivariate partial least squares was employed in 46 PDM women and 46 healthy controls (HC) during periovulatory, luteal, and menstruation phases. We identified neural networks associated with different aspects of empathy in both groups. Part of the obtained empathy-related network in PDM exhibited a similar activity compared with HC, including the right anterior insula and other regions, whereas others have an opposite activity in PDM, including the inferior frontal gyrus and right inferior parietal lobule. These results indicated an abnormal regulation to empathy in PDM. Furthermore, there was no difference in empathy association patterns in PDM between the pain and pain-free states. This study suggested that long-term pain experience may lead to an abnormal function of the brain network for empathy processing that did not vary with the pain or pain-free state across the menstrual cycle.

6.
Environ Sci Pollut Res Int ; 26(12): 12227-12236, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30835062

RESUMO

Electronic waste (e-waste) recycling has proven to be a significant source of phthalate (PAE) contamination in the environment. A detailed investigation was conducted to understand the concentration, distribution, profile and possible source of PAEs in residential and agricultural soils from Guiyu, Shantou, China, the largest e-waste processing and recycling areas in the world. Sixteen PAEs were analysed in 46 surface soil samples from three different sampling areas in terms of individual and total concentrations, together with pH and soil organic matter. High concentrations of the total PAEs were found in residential area A (more than 20,000 ng g-1), revealing a clear urban pulse, whereas in residential area B and agricultural areas, concentrations were lower than 10,000 ng g-1. The dominant PAEs were bis (2-nbutoxyethyl) phthalate, bis (4-methyl-2-pentyl) phthalate and dicyclohexyl phthalate. These PAEs were high-molecular weight PAEs (alkyl chains ≥ 6 carbons) and mainly derived from polyvinyl chloride commonly used in electrical and electronic equipment, indicating a distinctive composition in relation to the e-waste area. Three individual and the total PAEs exhibited significant positive correlations with pH. Principal component analysis indicated that PAEs were mainly distributed in three groups according to the alkyl chain length and potential source. This study showed that the informal e-waste recycling has already introduced PAEs into surrounding areas as a pollutant which should draw more attention and regulatory control.


Assuntos
Resíduo Eletrônico/análise , Monitoramento Ambiental , Ácidos Ftálicos/análise , Poluentes do Solo/análise , Agricultura , Carbono/análise , China , Ésteres/análise , Reciclagem , Solo/química
7.
Environ Sci Pollut Res Int ; 25(16): 15934-15942, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29589239

RESUMO

Widespread phthalate exposure has been recently documented and is hypothesized to increase blood pressure (BP) in humans. However, current studies have provided inconclusive evidence for an association between phthalate exposure and BP. Human epidemiologic studies on the topic remain lacking. Therefore, this study aims to examine the association between serum phthalate concentrations and BP in a Chinese population. We measured several parameters of BP (systolic BP, diastolic BP, total cholesterol, and triglyceride) and the concentrations of 16 phthalates (dimethyl phthalate (DMP), diethyl phthalate, diisobutyl phthalate, dibutyl phthalate (DBP), bis (2-methoxyethyl) phthalate, bis (4-methyl-2-pentyl) phthalate, bis (2-ethoxyethyl) phthalate, diamyl phthalate, dihexyl phthalate, benzyl butyl phthalate, bis (2-nbutoxyethyl) phthalate (DBEP), dicyclohexyl phthalate, bis (2-ethyl hexyl) phthalate (DEHP), diisononyl phthalate, diphenyl phthalate, and di-n-octyl phthalate) in the serum of 474 adults recruited from a primary health care clinic. The relationship between serum phthalate concentrations and BP parameters was assessed with multivariate linear regressions. DBP was the most ubiquitous and dominant contaminant in the study population. The systolic BP of subjects in the median-exposure DEHP group significantly increased by 2.96 mmHg (p < 0.05) relative to that of subjects in the low-exposure group. Significant positive dose-related associations of DMP and DBEP with the levels of total cholesterol in serum (p for trend < 0.05) were also found. These associations persisted even when considering exposure to multiple phthalates. Our results suggested that phthalate exposure might increase BP in adults. However, our findings warrant further studies in a larger and more general population.


Assuntos
Dietilexilftalato/química , Hipertensão , Ácidos Ftálicos/efeitos adversos , Ácidos Ftálicos/química , Triglicerídeos/química , China , Estudos Transversais , Humanos , Modelos Lineares , Triglicerídeos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA