Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Aquat Toxicol ; 274: 107035, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39106612

RESUMO

Bisphenol S (BPS) is extensively utilized in various industries such as plastic manufacturing, food packaging, and electronics. The release of BPS into aquatic environments has been observed to have negative impacts on aquatic ecosystems. Research has shown that exposure to BPS can have adverse effects on the health of aquatic animals. This study aimed to explore the mechanism of oxidative stress and endoplasmic reticulum stress induced in freshwater crayfish (Procambarus clarkii) by exposure to BPS (0 µg/L, 1 µg/L, 10 µg/L, and 100 µg/L) for 14 days. The results showed that BPS exposure resulted in elevated levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and severe intestinal histological damage. In addition, oxidative stress can occur in the body by inhibiting the activity of antioxidant enzymes and the expression of related genes. BPS exposure induced a significant increase in the relative mRNA expression levels of inflammatory cytokines (NF-κB and TNF-α) and key unfolded protein response (UPR) related genes (Bip, Ire1, and Xbp1). At the same time, BPS exposure also induced up-regulation of apoptosis genes (Cytc and Casp3), suggesting that UPR and Nrf2-Keap1 signaling pathways may play a protective role in the process of apoptosis and oxidative stress. In conclusion, Our findings present the initial evidence that exposure to environmentally relevant levels of BPS can lead to intestinal injury through various pathways, highlighting concerns about the potential harm at a population level from BPS and other bisphenol analogs.

2.
PLoS One ; 19(6): e0303525, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38865335

RESUMO

With the development of low-carbon economy and the dominant position of retailers, through the establishment and comparison of three cooperative advertising models: model of supplier's independent advertising, model of supplier's independent advertising and model of retailer's and supplier's cooperative advertising, this paper studies the cooperative advertising decision-making of fresh agricultural products supply chain with two channels, and the demand of both channels is affected by the level of advertising investment, the proportion of advertising cost sharing and the efficiency of carbon emission reduction. The results show that when supplier and retailer adopt the two-way cooperative advertising mode, the demand and profit level of the two channels reach the optimal level. Numerical analysis shows that carbon emission reduction efficiency has an important impact on profits and market demand, which is closely related to cooperative advertising strategy.


Assuntos
Publicidade , Publicidade/métodos , Carbono/química , Comércio , Agricultura/métodos , Abastecimento de Alimentos/economia , Abastecimento de Alimentos/métodos , Liderança , Modelos Teóricos
3.
Curr Res Food Sci ; 8: 100737, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38681525

RESUMO

Vegetable and fruit classification can help all links of agricultural product circulation to better carry out inventory management, logistics planning and supply chain coordination, and improve the efficiency and response speed of the supply chain. However, the current classification of vegetables and fruits mainly relies on manual classification, which inevitably introduces the influence of human subjective factors, resulting in errors and misjudgments in the classification of vegetables and fruits. In response to this serious problem, this research proposes an efficient and reproducible novel model to classify multiple vegetables and fruits using handcrafted features. In the proposed model, preprocessing operations such as Gaussian filtering, grayscale and binarization are performed on the pictures of vegetables and fruits to improve the quality of the pictures; statistical texture features representing vegetable and fruit categories, wavelet transform features and shape features are extracted from the preprocessed images; the feature dimension reduction method of diffusion maps is used to reduce the redundant information of the combined features composed of statistical texture features, wavelet transform features and shape features; five effective machine learning methods were used to classify the types of vegetables and fruits. In this research, the proposed method was rigorously verified experimentally and the results show that the SVM classifier achieves 96.25% classification accuracy of vegetables and fruits, which proves that the proposed method is helpful to improve the quality and management level of vegetables and fruits, and provide strong support for agricultural production and supply chain.

4.
J Vasc Access ; : 11297298221126811, 2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36203373

RESUMO

BACKGROUND: The peripheral intravenous catheter (PIVC) is an important strategy for the treating the illness of pediatric patients. However, the success rate of traditional PIVC method, such as the landmark technique, might be significantly variable and unstable. The near infrared-assisted PIVC might be another option and the results can be revealed by a systemic review and meta-analysis of randomized clinical trials (RCT). METHODS: A systematic search and a meta-analysis for the RCT of near infrared-assisted PIVC on pediatric patients. The near infrared-assisted and traditional PIVC was compared to evaluate the first time success rate, number of attempts, and attempt duration. Seven RCT studies and total 1068 pediatric patients were enrolled in this meta-analysis. The subgroup analysis of vessel grade difficulty was also performed. RESULTS: The near infrared-assisted PIVC showed a significantly higher odds ratio of first time success rate when compared to traditional PIVC. In addition, the number of attempts and attempt duration were significantly reduced in the group of near infrared-assisted PIVC. At last, the subgroup analysis of vessel grade difficultly showed that the first time success rate was borderline significantly increased in the subgroup of difficult vessel grade. In addition, the number of attempts was significantly reduced in the subgroup of difficult vessel grade. CONCLUSIONS: The near infrared-assisted PIVC might be an option for the PIVC on pediatric patients. The advantages of increased first time success rate and decreased number of attempts and attempt duration should be considered by the clinicians and nurses.

5.
Sci Rep ; 12(1): 2707, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35177730

RESUMO

Root zone microbial structure is particularly complex in plants with rhizosheaths, and greater understanding of the rhizosheath may play an important role in the future development of sustainable agricultural practices. However, one important reason to focus study on rhizosheath microbial structure is that there is no definite method for rhizosheath separation. The aim of this study was to explore rhizosheath isolation methods and the diversity characteristics of microorganisms around the rhizosphere. In this study, we isolated the rhizosheath of Stipa grandis, a dominant species in desert steppe, and the microorganisms in the roots, root epidermis, rhizosheath and rhizosphere soil were extracted and sequenced by 16S rRNA and ITS. The alpha diversity index of bacteria in Stipa grandis rhizosphere soil was the greatest, followed by rhizosheath, and the alpha diversity index of endophytic bacteria in root system was the smallest. The alpha diversity index of fungi in the rhizosheath and rhizosphere soil were significantly higher than that in the root epidermis and root system. There were significant differences in bacterial community structure between the root epidermis, endophytic bacteria, rhizosheath and rhizosphere soil. Unlike bacterial community structure, the community structure of fungi in the root epidermis was similar that of endophytic fungi, but significantly different from those in rhizosheath and rhizosphere soil. This study demonstrated a feasible method for separating plant rhizosheath and root epidermis. We suggest that the root epidermis can act as the interface between the host plant root and the external soil environment. We will have to re-examine the biological and ecological significance of rhizosheath and microorganisms in rhizosheath, as well as the mechanism explaining the close relationship of the rhizosheath and the plant root epidermis. This study provides theoretical and technical guidance for the isolation of the plant rhizosheath and the study of microorganisms in plant rhizosheath.


Assuntos
Microbiota/genética , Raízes de Plantas/microbiologia , Poaceae/microbiologia , Bactérias/genética , Fungos/genética , RNA Ribossômico 16S , Rizosfera , Solo , Microbiologia do Solo
6.
Exp Cell Res ; 408(2): 112863, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34626587

RESUMO

Forkhead box M1 (FOXM1) has been reported to play a protective role against acute kidney injury by driving tubular regeneration. This study aims to probe the function of FOXM1 in diabetic nephropathy (DN) and the molecules involved. FOXM1 was poorly expressed in DN-diseased kidney tissues. A murine model of DN was established, and podocytes cells (MPC5) were treated with high-glucose (HG) for in vitro studies. FOXM1 overexpression improved kidney function and reduced pathological changes in mice, and it increased the expression of the podocyte marker Nephrin in kidney tissues. In vitro, FOXM1 increased viability and reduced pyroptosis of the HG-treated MPC5 cells, and it elevated the expression of the podocyte marker Nephrin whereas reduced the expression of pyroptosis-related NLRP3 inflammasome and cleaved caspase 1. FOXM1 bound to the promoter of sirtuin 4 (SIRT4) to induce transcriptional activation. Downregulation of SIRT4 blocked the protective roles of FOXM1 both in vivo and in vitro. Phosphorylation of nuclear factor-kappa B (NF-κB) in HG-treated cells was suppressed by FOXM1 but restored after SIRT4 inhibition. In conclusion, this study suggested that FOXM1 transcriptionally activates SIRT4 and inhibits NF-κB signaling and the NLRP3 inflammasome to alleviate kidney injury and podocyte pyroptosis in DN.


Assuntos
Injúria Renal Aguda/genética , Nefropatias Diabéticas/genética , Proteína Forkhead Box M1/genética , Proteínas Mitocondriais/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Sirtuínas/genética , Injúria Renal Aguda/patologia , Animais , Nefropatias Diabéticas/patologia , Regulação da Expressão Gênica/genética , Humanos , Inflamassomos/genética , Rim/lesões , Rim/metabolismo , Rim/patologia , Camundongos , NF-kappa B/genética , Podócitos/metabolismo , Podócitos/patologia , Piroptose/genética , Transdução de Sinais
7.
BMC Plant Biol ; 21(1): 436, 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34563114

RESUMO

BACKGROUND: Nitrogen, as a limiting factor for net primary productivity in grassland ecosystems, is an important link in material cycles in grassland ecosystems. However, the nitrogen assimilation efficiency and mechanisms of grassland plants under grazing disturbance are still unclear. This study investigated Stipa breviflora desert steppe which had been grazed for 17 years and sampled the root system and leaf of the constructive species Stipa breviflora during the peak growing season under no grazing, light grazing, moderate grazing and heavy grazing treatments. The activities of enzymes related to nitrogen assimilation in roots and leaves were measured. RESULTS: Compared with no grazing, light grazing and moderate grazing significantly increased the activities of nitrate reductase (NR), glutamine synthetase (GS), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) in leaves, and GS, GOT and GPT in roots of Stipa breviflora, while heavy grazing significantly decreased the activities of GS in leaves and NR in roots of Stipa breviflora. NR, GOT and GPT activities in leaves and roots of Stipa breviflora were positively correlated with nitrogen content, soluble protein, free amino acid and nitrate content. CONCLUSIONS: Grazing disturbance changed the activities of nitrogen assimilation related enzymes of grassland plants, and emphasized that light grazing and moderate grazing were beneficial for nitrogen assimilation by grassland plants. Therefore, establishing appropriate stocking rates is of great significance for material flows in this grassland ecosystem and for the stability and sustainable utilization of grassland resources.


Assuntos
Ativação Enzimática/fisiologia , Pradaria , Herbivoria , Nitrogênio/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Poaceae/metabolismo , Alanina Transaminase/metabolismo , Aspartato Aminotransferases/metabolismo , China , Glutamato-Amônia Ligase/metabolismo , Nitrato Redutase/metabolismo
8.
J Hazard Mater ; 402: 123508, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721641

RESUMO

Plasmonic Au-Ag/TiO2 bimetallic nanocatalyst is regarded as a promising visible-light (VL) photocatalyst due to its wide light absorption and potentially enhanced activity. For its preparation, Au precursors usually contain Cl and co-impregnation/co-deposition suffers from AgCl precipitation, and consequently Au and Ag have to be sequentially supported. However, Au and Ag species of the sequential preparation are individually isolated and difficult to be homogeneously mixed. Here we report an Au-Ag plasmonic nanocatalyst achieved by plasma restructuring and activation from the sequential preparation. The isolated cationic Au and Ag species on the sequentially-prepared Au-Ag/TiO2 sample are restructured to be homogeneously mixed and highly activated by O2 plasma, which can be partially auto-reduced to Au-Ag bimetallic nanoparticles within the induction period of a few minutes in VL photocatalytic oxidation of CO. The Au-Ag plasmonic nanocatalyst exhibits a strongly enhanced activity in the VL photocatalytic reaction. The contribution of O2 plasma treatment and the enhancement mechanism for the Au-Ag plasmonic nanocatalyst are disclosed.

9.
Saudi J Biol Sci ; 24(8): 1815-1817, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29551929

RESUMO

OBJECTIVE: Clinical symptoms of diabetic nephropathy patients and non-diabetic nephropathy are compared and analyzed, hemodialysis effect and quality of life of two kinds of nephrotic patients are analyzed. METHODS: Respectively extract 1300 cases of diabetic nephropathy and non-diabetic nephropathy patients admitted to different hospitals during December 2011-December 2014. Based on whether the patient suffers from diabetes, they were divided into diabetic group and control group. Hemodialysis of two groups of patients were followed up to observe effectiveness of blood treatment, and complications were observed after one year of follow-up. RESULTS: Hematodialysis effectiveness of diabetic nephropathy patients is significantly lower than that of non-diabetic nephropathy group. After 1 year's follow-up, it can be found that survival rate of diabetic nephropathy patients is much lower than that of control group. In statistical comparison of data involved in the two groups of patients, P < 0.05, the difference is statistically significant. CONCLUSION: Treatment effect of diabetic nephropathy patients is relatively poor compared to that of non-diabetic patients. In clinics, management and prevention of diabetic patients should be strengthened to avoid complication of nephropathy which brings serious injury to patients.

10.
Bioresour Technol ; 139: 280-4, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23665688

RESUMO

In order to understand the improvement effect of potassium (K) on the catalytic activity of iron-loaded calcined scallop shell (CS) for the steam reforming tar derived from biomass, various K precursors were applied for the catalyst preparation. It is found that pompom-like iron-based particles with a mesoporous structure were easily formed on the surface of calcined scallop shell (CS) when K2CO3 was used as K precursor while no such kind of microsphere was formed when other kinds of K precursors such as KOH and KNO3 were applied. The optimum K-loading amount for the preparation of this catalyst was investigated. Based on the experimental results obtained, a mechanism for the formation of these microspheres was proposed. This pompom-like potassium-promoted iron-based catalyst showed a better catalytic activity and reusability for the steam reforming of tar derived from lignin.


Assuntos
Exoesqueleto/química , Ferro/química , Lignina/química , Pectinidae/anatomia & histologia , Potássio/química , Vapor , Alcatrões/química , Animais , Catálise , Carvão Vegetal/química , Reciclagem
11.
J Hazard Mater ; 239-240: 362-9, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23021101

RESUMO

At room temperature, the enhanced effect of water vapor on ozone catalytic oxidation (OZCO) of formaldehyde to CO2 over MnOx catalysts and the reaction stability was reported. In a dry air stream, only below 20% of formaldehyde could be oxidized into CO2 by O3. In humid air streams (RH≥55%), ∼100% of formaldehyde were oxidized into CO2 by O3 and the reaction stability was significantly enhanced. Meanwhile, in situ Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectra of OZCO of HCHO demonstrate that the amount of both monodentate and bidentate carbonate species on MnOx, in the dry stream, increased gradually with time on stream (TOS). However, in the humid stream, almost no accumulation of carbonate species on the catalysts was observed. To clarify the enhanced mechanism, formaldehyde surface reactions and CO2 adsorption/desorption on the fresh, O3 and O3+H2O treated MnOx catalysts were examined comparatively.


Assuntos
Poluentes Atmosféricos/química , Formaldeído/química , Compostos de Manganês/química , Óxidos/química , Ozônio/química , Vapor , Adsorção , Poluição do Ar em Ambientes Fechados , Dióxido de Carbono/química , Catálise , Peróxido de Hidrogênio/química , Oxidantes/química , Oxirredução , Temperatura
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(9): 1589-93, 2006 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-17112023

RESUMO

Atomic hydrogen plays important roles in chemical vapor deposition of functional materials, plasma etching, and surface cleaning. The present work introduces the fundamental principle to determine atomic hydrogen density via optical emission spectroscopy using Ar as an actinometer, and also reports the experimental results of atomic hydrogen density in the DBD discharge hydrogen plasmas. The variations of atomic hydrogen density and the hydrogen dissociation fraction as a function of pressure were calculated based on some of the available electron-impact excitation cross section and quenching cross sections in the literatures. In this work, as the pressure increases from 0.32 to 5.1 kPa, the hydrogen dissociation fraction decreases from 5.2% to 0.089%, and the atomic hydrogen density decreases from 4.9 x 10(15) cm(-3) to 1.3 x 10(15) cm(-3). The variations of H atom Balmer lines and Ar (750.4 nm) emission intensity as functions of gas pressure, discharge voltage, and frequency were also investigated.

13.
Rapid Commun Mass Spectrom ; 19(9): 1159-66, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15803516

RESUMO

Atomic hydrogen plays important roles in chemical vapor deposition of functional materials, plasma etching and new approaches to chemical synthesis of hydrogen-containing compounds. The present work reports experimental determinations of atomic hydrogen near the grounded electrode in medium-pressure dielectric barrier discharge hydrogen plasmas by means of molecular beam threshold ionization mass spectrometry (MB-TIMS). At certain discharge conditions (a.c. frequency of 24 kHz, 28 kV of peak-to-peak voltage), the measured hydrogen dissociation fraction is decreased from approximately 0.83% to approximately 0.14% as the hydrogen pressure increases from 2.0 to 14.0 Torr. A simulation method for extraction of the approximate electron beam energy distribution function in the mass spectrometer ionizer and a semi-quantitative approach to calibrate the mass discrimination effect caused by the supersonic beam formation and the mass spectrometer measurement are reported.

14.
Chem Commun (Camb) ; (12): 1418-9, 2003 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-12841270

RESUMO

At temperatures above 350 degrees C, significant amounts of NOx formed from N2 and O2 have been observed in Cu-ZSM-5 catalyst-pellet filled dielectric barrier discharges, indicating the necessity of using low-temperature performance in all plasma-catalytic processes for removal of air pollutants.

15.
Zhong Yao Cai ; 25(7): 489-91, 2002 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-12599761

RESUMO

OBJECTIVE: To study the therapeutic effects of inrigorating the kidney and strengthening the bones capsule(IKSBC) on osteoporotic ovariectomized(OVX) rat model. METHODS: The concentrations of calcium, phosphorus and ALP in serum of ovariectomized rats were determined by clinical biochemical assay, and the right hind leg thighbones of ovariectomized rats were reserved for the preparation of bone specimens and were studied by bone histomorphometry. RESULTS: After treatment with IKSBC, the concentrations of calcium and phosphorus in ovariectomized rat serum were increased, the activity of ALP was decreased and the percentage of relative trabecular volume was increased significantly as compared with that before treatment(P < 0.05). CONCLUSION: IKSBC possesses some therapeutic effects on osteoporotic rat model.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Osteoporose/sangue , Plantas Medicinais , Fosfatase Alcalina/sangue , Animais , Cálcio/sangue , Cápsulas , Medicamentos de Ervas Chinesas/isolamento & purificação , Feminino , Fêmur/patologia , Osteoporose/patologia , Ovariectomia , Fósforo/sangue , Plantas Medicinais/química , Ratos , Ratos Wistar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA