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1.
Sci Total Environ ; 953: 176182, 2024 Nov 25.
Article de Anglais | MEDLINE | ID: mdl-39270863

RÉSUMÉ

Grasslands are being threatened by global drought and warming. Economic assessments of changing grassland carbon sequestration, a prerequisite for nature-based climate-change mitigation policies, are limited when researchers inadequate consider interactions between drought and warming. Here, we quantified the responses of 35 grass biomasses to combined drought and warming, based on manipulation experiments from 34 peer-reviewed papers; subsequently, we matched them with grasslands in northern China-the eastern range of the larger Eurasian Steppe-and further projected the economic implications for carbon market trading and carbon-sequestration costs. The results show that carbon sequestration in all grassland types, except for forbrich steppe, was significantly reduced by the synergistic interactions of drought and warming. Approximately 10 % of the grasslands in central Xinjiang, identified as forbrich steppe, showed resilience to these stressors. In contrast, the rest of northern China's grasslands suffered increased carbon losses due to drought and warming. The combined effects of drought and warming have caused a loss of 1.6 × 104 million Chinese yuan (CNY) in revenue and excess carbon-sequestration costs exceeding 1.1 × 105 million CNY. Overall, our study results indicate that the synergistic effects of drought and warming significantly undermine the economic viability of carbon sequestration in most of northern China's grasslands. As climate change intensifies, understanding and incorporating the complex interactions of drought and warming can aid in the sustainable management of grassland ecosystems and the development of effective climate-change mitigation policies in arenas, including carbon markets.

2.
J Hazard Mater ; 476: 135135, 2024 Sep 05.
Article de Anglais | MEDLINE | ID: mdl-38986409

RÉSUMÉ

Rhizosphere bacteria are critical for supporting plant performance in stressful environments. Understanding the assembly and co-occurrence of rhizosphere bacterial communities contributes significantly to both plant growth and heavy metal accumulation. In this study, Ligustrum lucidum and Melia azedarach were planted in soils with simulated varying levels of Pb-Zn contamination. The Rhizosphere bacterial communities were investigated by using 16S rRNA gene sequencing. The impacts of Pb-Zn contamination on the diversity and structure of the rhizosphere bacterial community were found to be greater than those of both tree species. The variation in bacterial community structure in both trees was mainly driven by the combinations of Pb-Zn and soil properties. Deterministic processes (non-planted, 82 %; L. lucidum, 73 %; M. azedarach, 55 %) proved to be the most important assembly processes for soil bacterial communities, but both trees increased the importance of stochastic processes (18 %, 27 %, 45 %). The rhizosphere co-occurrence networks exhibited greater stability compared to the non-planted soil networks. Rare taxa played a dominant role in maintaining the stability of rhizosphere networks, as most of the keystone taxa within rhizosphere networks belonged to rare taxa. Dissimilarities in the structure and network complexity of rhizosphere bacterial communities were significantly associated with differences in tree biomass and metal accumulation. These variations in response varied between both trees, with L. lucidum exhibiting greater potential for phytoremediation in its rhizosphere compared to M. azedarach. Our results offer valuable insights for designing effective microbe-assisted phytoremediation systems.


Sujet(s)
Bactéries , Plomb , ARN ribosomique 16S , Rhizosphère , Microbiologie du sol , Polluants du sol , Zinc , Plomb/toxicité , Bactéries/génétique , Bactéries/classification , Bactéries/métabolisme , ARN ribosomique 16S/génétique , Arbres/microbiologie , Microbiote , Dépollution biologique de l'environnement
3.
Sci Rep ; 14(1): 13896, 2024 06 17.
Article de Anglais | MEDLINE | ID: mdl-38886500

RÉSUMÉ

The etiology and pathophysiology of heart failure are still unknown. Increasing evidence suggests that abnormal microRNAs (miRNAs) and transcription factors (TFs) expression may be associated with the development of heart failure. Therefore, this study aims to explore key miRNAs, TFs, and related genes in heart failure to gain a greater understanding of the pathogenesis of heart failure. To search and download the dataset of mRNA chips related to heart failure from the GEO database (GSE59867, GSE9128, and GSE134766), we analyzed differential genes and screened the common differentially expressed genes on two chips using R language software. The binary interactions and circuits among miRNAs, TFs, and corresponding genes were determined by Pearson correlation coefficient. A regulatory network of miRNAs, TFs, and target genes was constructed based on bioinformatics. By comparing the sequences of patients with and without heart failure, five downregulated genes with hypermethylated mRNA and three upregulated genes with hypomethylated mRNA were identified. The miRNA-TF gene regulatory network consisted of 26 miRNAs, 22 TFs and six genes. GO and KEGG analysis results revealed that BP terms like cellular response to organic substance, cellular response to cytokine stimulus, and KEGG pathways like osteoclast differentiation, MAPK signaling pathway, and legionellosis were enriched of the DEGs. TMEM87A, PPP2R2A, DUSP1, and miR-92a have great potential as biomarkers for heart failure. The integrated analysis of the mRNA expression spectrum and microRNA-transcription factor-gene revealed the regulatory network of heart failure, which may provide clues to its alternative treatment.


Sujet(s)
Analyse de profil d'expression de gènes , Réseaux de régulation génique , Défaillance cardiaque , microARN , Facteurs de transcription , microARN/génétique , Défaillance cardiaque/génétique , Humains , Facteurs de transcription/génétique , Facteurs de transcription/métabolisme , Biologie informatique/méthodes , Régulation de l'expression des gènes , ARN messager/génétique , ARN messager/métabolisme , Bases de données génétiques
4.
Front Microbiol ; 15: 1372866, 2024.
Article de Anglais | MEDLINE | ID: mdl-38525071

RÉSUMÉ

Soil enzymes play a central role in carbon and nutrient cycling, and their activities can be affected by drought-induced oxygen exposure. However, a systematic global estimate of enzyme sensitivity to drought in wetlands is still lacking. Through a meta-analysis of 55 studies comprising 761 paired observations, this study found that phosphorus-related enzyme activity increased by 38% as result of drought in wetlands, while the majority of other soil enzyme activities remained stable. The expansion of vascular plants under long-term drought significantly promoted the accumulation of phenolic compounds. Using a 2-week incubation experiment with phenol supplementation, we found that phosphorus-related enzyme could tolerate higher biotoxicity of phenolic compounds than other enzymes. Moreover, a long-term (35 years) drainage experiment in a northern peatland in China confirmed that the increased phenolic concentration in surface layer resulting from a shift in vegetation composition inhibited the increase in enzyme activities caused by rising oxygen availability, except for phosphorus-related enzyme. Overall, these results demonstrate the complex and resilient nature of wetland ecosystems, with soil enzymes showing a high degree of adaptation to drought conditions. These new insights could help evaluate the impact of drought on future wetland ecosystem services and provide a theoretical foundation for the remediation of degraded wetlands.

5.
Article de Anglais | MEDLINE | ID: mdl-36430004

RÉSUMÉ

The contradiction between urban expansion and ecological protection in fragile vegetation areas has become increasingly prominent with regional development. Revealing the relationship between urbanization and ecosystem services will help to provide solutions to this problem. In order to clarify the impact of urbanization on typical mountain areas with fragile vegetation on the Qinghai Tibet Plateau, we built an ecosystem service value (ESV) evaluation index system. We also evaluated the ESV and its spatial response to the urbanization of Shannan Prefecture in Tibet from 1990 to 2015 based on different terrain gradients (TGs) using vegetation biophysical data obtained from remote sensing platforms. The results show that ESV in Shannan increased first and then declined as the TG increased, reaching a maximum value at the third TG. ESV showed a decreased trend during the study period, with a significant decline at the second and third TGs, which were the main distribution areas of vegetation in Shannan. Through spatial correlation analysis, we observed that urbanization and ESV showed a significant spatial aggregation effect. Among them, the high-low type accounted for the largest proportion in the grid with the agglomeration effect, mainly concentrated at the lower TG in the southern of Shannan, where ESV decreases with the increasing urbanization. We highlight the need for targeted, sustainable development policies to rationally organize the urbanization process in the different-gradient plateau regions with fragile vegetation. These results can provide a reference for applying ESV to vegetation restoration and ecological protection in ecologically fragile mountain areas.


Sujet(s)
Écosystème , Urbanisation , Développement durable , Analyse spatiale , Politique (principe)
6.
Front Nutr ; 8: 718517, 2021.
Article de Anglais | MEDLINE | ID: mdl-34712685

RÉSUMÉ

Peppers (Capsicum spp.) are used as food items, and particularly condiments, across most of the world. Accordingly, these vegetables occupy the largest annual stable planting area (>21,000 km2) in China. However, pepper growth, cultivation systems, yield formation, and cultivar traits vary among different environments. China is characteristic for its widely diverse terrains and high ecological heterogeneity, which determine its unique pepper consumption habits and cultivation patterns. The present study provides a comprehensive overview and analysis of the geographical and ecological characteristics of Chinese pepper consumption habits and cultivation systems, and the influence of climatic and human factors on the national pepper planting industry. For this, we analyzed detailed geospatial datasets and reviewed relevant policy papers and academic literature. Based on those findings, we then proposed sustainable management strategies for China's pepper industry; we offered suggestions for aligning the continued development of pepper cultivation with the national objective of achieving an ecological civilization and the nutritional requirements of an increasingly affluent and diverse population.

7.
Proc Natl Acad Sci U S A ; 117(25): 14593-14601, 2020 06 23.
Article de Anglais | MEDLINE | ID: mdl-32513694

RÉSUMÉ

Gross domestic product (GDP) summarizes a vast amount of economic information in a single monetary metric that is widely used by decision makers around the world. However, GDP fails to capture fully the contributions of nature to economic activity and human well-being. To address this critical omission, we develop a measure of gross ecosystem product (GEP) that summarizes the value of ecosystem services in a single monetary metric. We illustrate the measurement of GEP through an application to the Chinese province of Qinghai, showing that the approach is tractable using available data. Known as the "water tower of Asia," Qinghai is the source of the Mekong, Yangtze, and Yellow Rivers, and indeed, we find that water-related ecosystem services make up nearly two-thirds of the value of GEP for Qinghai. Importantly most of these benefits accrue downstream. In Qinghai, GEP was greater than GDP in 2000 and three-fourths as large as GDP in 2015 as its market economy grew. Large-scale investment in restoration resulted in improvements in the flows of ecosystem services measured in GEP (127.5%) over this period. Going forward, China is using GEP in decision making in multiple ways, as part of a transformation to inclusive, green growth. This includes investing in conservation of ecosystem assets to secure provision of ecosystem services through transregional compensation payments.


Sujet(s)
Conservation des ressources naturelles/économie , Prise de décision , Écosystème , Modèles économiques , Développement durable , Chine
8.
Front Microbiol ; 10: 254, 2019.
Article de Anglais | MEDLINE | ID: mdl-30828326

RÉSUMÉ

Objective: To identify the pathogen causing fungemia in a Chinese patient and describe its morphological and molecular characterizes. Methods: Samples of central and peripheral venous blood were collected for blood culture. Morphology and drug sensitivities of the isolated yeast-like fungus were analyzed. rDNA sequencing and molecular phylogenetic analysis of the isolated strains were performed using DNAMAN and MEGA software. Results: A strain of yeast-like fungi was repeatedly isolated from blood samples of a Chinese patient. The isolates grew well on sabouraud medium broth plate. The colonies were smooth and round at 28°C, and were of rough surface and irregular shape at 35°C. Molecular phylogenetic trees constructed based on the internal transcribed spacer (ITS) and D1/D2 domains of 28S rDNA gene demonstrated the isolated yeast-like fungus was Moesziomyces antarcticus. Drug susceptibility test showed that this isolated M. antarcticus was resistant or had relatively low susceptibility to flucytosine, fluconazole, voriconazole, and itraconazole, and only sensitive to amphotericin. Conclusion: This study provided more information for the molecular and morphology characteristics of M. antarcticus and reviewed the species information of Moesziomyces associated with human infections, which will contribute to the identification and diagnosis of Moesziomyces infections.

9.
Dig Dis Sci ; 64(5): 1226-1237, 2019 05.
Article de Anglais | MEDLINE | ID: mdl-30535782

RÉSUMÉ

BACKGROUND: Hepatitis C virus (HCV) has been classified as a strictly hepatotropic pathogen for a long time, and hepatocytes are target cells for HCV infection. More and more studies showed non-liver cells supported HCV entry and replication, such as macrophages. The mechanisms of HCV entry into macrophages are still not clear. AIMS: This study aims to determine the way of HCV entry into macrophages. METHODS: Cell culture-derived infectious HCV particles (HCVcc) were prepared using Huh7 cells transfected with HCV RNA. CD81-knockdown cells were obtained through siRNA transfection. HCV RNA levels were determined by RT-qPCR. Flow cytometry analyses were used to determine cell surface levels of CD11b, CD68, and CD81. ELISA and western blotting were performed to quantify the protein levels of IL-1ß, IL-6, and TNF-α. Phagocytic ability was determined by neutral red uptake assay. RESULTS: CD81 knockdown could not inhibit HCVcc entry into macrophages. The entry of HCV into macrophages could not be blocked by pooled IgG from chronic hepatitis C patient's sera. Macrophages derived from THP-1 cells displayed stronger phagocytic capacity, which also swallowed more HCV RNA. Treatment of macrophages with endocytic inhibitor, methyl-ß-cyclodextrin, decreased the internalization of HCV. HCV uptake by macrophages was related to the reorganization of F-actin cytoskeleton and PI3Ks activation. HCV infection significantly increased the expression of IL1ß and IL6 in macrophages and promoted apoptosis of macrophages. CONCLUSIONS: HCV entry into macrophages mainly depends on phagocytosis of macrophages.


Sujet(s)
Hepacivirus/métabolisme , Macrophages/métabolisme , Macrophages/virologie , Monocytes/métabolisme , Monocytes/virologie , Phagocytose/physiologie , Animaux , Cellules cultivées , 4H-1-Benzopyran-4-ones/pharmacologie , Relation dose-effet des médicaments , Humains , Macrophages/effets des médicaments et des substances chimiques , Souris , Souris de lignée BALB C , Monocytes/effets des médicaments et des substances chimiques , Morpholines/pharmacologie , Phagocytose/effets des médicaments et des substances chimiques , Cellules RAW 264.7 , Lapins
10.
Article de Anglais | MEDLINE | ID: mdl-29507067

RÉSUMÉ

The use of azole fungicides in agriculture is believed to be one of the main reasons for the emergence of azole resistance in Aspergillus fumigatus Though widely used in agriculture, imidazole fungicides have not been linked to resistance in A. fumigatus This study showed that elevated MIC values of imidazole drugs were observed against A. fumigatus isolates with TR34/L98H/S297T/F495I mutation, but not among isolates with TR34/L98H mutation. Short-tandem-repeat (STR) typing analysis of 580 A. fumigatus isolates from 20 countries suggested that the majority of TR34/L98H/S297T/F495I strains from China were genetically different from the predominant major clade comprising most of the azole-resistant strains and the strains with the same mutation from the Netherlands and Denmark. Alignments of sterol 14α-demethylase sequences suggested that F495I in A. fumigatus was orthologous to F506I in Penicillium digitatum and F489L in Pyrenophora teres, which have been reported to be associated with imidazole resistance. In vitro antifungal susceptibility testing of different recombinants with cyp51A mutations further confirmed the association of the F495I mutation with imidazole resistance. In conclusion, this study suggested that environmental use of imidazole fungicides might confer selection pressure for the emergence of azole resistance in A. fumigatus.


Sujet(s)
Antifongiques/pharmacologie , Aspergillus fumigatus/effets des médicaments et des substances chimiques , Aspergillus fumigatus/génétique , Cytochrome P-450 enzyme system/génétique , Résistance des champignons aux médicaments/génétique , Protéines fongiques/génétique , Imidazoles/pharmacologie , Sterol 14-demethylase/génétique , Agriculture/méthodes , Séquence d'acides aminés , Aspergillose/traitement médicamenteux , Aspergillus fumigatus/isolement et purification , Humains , Tests de sensibilité microbienne , Sélection génétique/génétique , Alignement de séquences
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