Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 253
Filtrar
1.
ISME Commun ; 4(1): ycae017, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38481578

RESUMO

Recent metagenomic advancements have offered unprecedented insights into soil viral ecology. However, it remains a challenge to select the suitable metagenomic method for investigating soil viruses under different environmental conditions. Here, we assessed the performance of viral size-fraction metagenomes (viromes) and total metagenomes in capturing viral diversity from hypersulfidic soils with neutral pH and sulfuric soils with pH <3.3. Viromes effectively enhanced the sequencing coverage of viral genomes in both soil types. Viomes of hypersulfidic soils outperformed total metagenomes by recovering a significantly higher number of viral operational taxonomic units (vOTUs). However, total metagenomes of sulfuric soils recovered ~4.5 times more vOTUs than viromes on average. Altogether, our findings suggest that the choice between viromes and total metagenomes for studying soil viruses should be carefully considered based on the specific environmental conditions.

2.
mSystems ; 9(4): e0105523, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38501864

RESUMO

Plant-associated diazotrophs strongly relate to plant nitrogen (N) supply and growth. However, our knowledge of diazotrophic community assembly and microbial N metabolism in plant microbiomes is largely limited. Here we examined the assembly and temporal dynamics of diazotrophic communities across multiple compartments (soils, epiphytic and endophytic niches of root and leaf, and grain) of three cereal crops (maize, wheat, and barley) and identified the potential N-cycling pathways in phylloplane microbiomes. Our results demonstrated that the microbial species pool, influenced by site-specific environmental factors (e.g., edaphic factors), had a stronger effect than host selection (i.e., plant species and developmental stage) in shaping diazotrophic communities across the soil-plant continuum. Crop diazotrophic communities were dominated by a few taxa (~0.7% of diazotrophic phylotypes) which were mainly affiliated with Methylobacterium, Azospirillum, Bradyrhizobium, and Rhizobium. Furthermore, eight dominant taxa belonging to Azospirillum and Methylobacterium were identified as keystone diazotrophic taxa for three crops and were potentially associated with microbial network stability and crop yields. Metagenomic binning recovered 58 metagenome-assembled genomes (MAGs) from the phylloplane, and the majority of them were identified as novel species (37 MAGs) and harbored genes potentially related to multiple N metabolism processes (e.g., nitrate reduction). Notably, for the first time, a high-quality MAG harboring genes involved in the complete denitrification process was recovered in the phylloplane and showed high identity to Pseudomonas mendocina. Overall, these findings significantly expand our understanding of ecological drivers of crop diazotrophs and provide new insights into the potential microbial N metabolism in the phyllosphere.IMPORTANCEPlants harbor diverse nitrogen-fixing microorganisms (i.e., diazotrophic communities) in both belowground and aboveground tissues, which play a vital role in plant nitrogen supply and growth promotion. Understanding the assembly and temporal dynamics of crop diazotrophic communities is a prerequisite for harnessing them to promote plant growth. In this study, we show that the site-specific microbial species pool largely shapes the structure of diazotrophic communities in the leaves and roots of three cereal crops. We further identify keystone diazotrophic taxa in crop microbiomes and characterize potential microbial N metabolism pathways in the phyllosphere, which provides essential information for developing microbiome-based tools in future sustainable agricultural production.


Assuntos
Microbiota , Microbiota/genética , Agricultura , Solo/química , Nitrogênio/análise , Produtos Agrícolas/metabolismo , Desenvolvimento Vegetal
3.
Sci Total Environ ; 921: 171227, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38402820

RESUMO

Understanding the assembly mechanisms of microbial communities, particularly comammox Nitrospira, in agroecosystems is crucial for sustainable agriculture. However, the large-scale distribution and assembly processes of comammox Nitrospira in agricultural soils remain largely elusive. We investigated comammox Nitrospira abundance, community structure, and assembly processes in 16 paired upland peanuts and water-logged paddy soils in south China. Higher abundance, richness, and network complexity of comammox Nitrospira were observed in upland soils than in paddy soils, indicating a preference for upland soils over paddy soils among comammox Nitrospira taxa in agricultural environments. Clade A.2.1 and clade A.1 were the predominant comammox Nitrospira taxa in upland and paddy soils, respectively. Soil pH was the most crucial factor shaping comammox Nitrospira community structure. Stochastic processes were found to predominantly drive comammox Nitrospira community assembly in both upland and paddy soils, with deterministic processes playing a more important role in paddy soils than in upland soils. Overall, our findings demonstrate the higher stochasticity of comammox Nitrospira in upland soils than in the adjacent paddy soils, which may have implications for autotrophic nitrification in acidic agricultural soils.


Assuntos
Amônia , Solo , Solo/química , Oxirredução , Bactérias , Nitrificação , Filogenia , Archaea
4.
Oral Oncol ; 150: 106715, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340546

RESUMO

Solitary fibrous tumor (SFT) represents an uncommon spindle cell sarcoma predominantly situated within soft tissue, with a notably infrequent occurrence in the nasal cavity and paranasal sinuses. In this report, we present a case involving a middle-aged male with a sizable solitary fibrous tumor affecting both the nasal and oral cavities.


Assuntos
Neoplasias Nasais , Seios Paranasais , Sarcoma , Tumores Fibrosos Solitários , Pessoa de Meia-Idade , Humanos , Masculino , Neoplasias Nasais/diagnóstico , Neoplasias Nasais/patologia , Tumores Fibrosos Solitários/diagnóstico , Seios Paranasais/patologia , Cavidade Nasal/patologia , Sarcoma/patologia
5.
Environ Int ; 185: 108511, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38382404

RESUMO

Fungal plant pathogens threaten crop production and sustainable agricultural development. However, the environmental factors driving their diversity and nationwide biogeographic model remain elusive, impacting our capacity to predict their changes under future climate scenarios. Here, we analyzed potential fungal plant pathogens from 563 samples collected from 57 agricultural fields across China. Over 28.0% of fungal taxa in the phyllosphere were identified as potential plant pathogens, compared to 22.3% in the rhizosphere. Dominant fungal plant pathogen groups were Cladosporium (in the phyllosphere) and Fusarium (in the rhizosphere), with higher diversity observed in the phyllosphere than in rhizosphere soil. Deterministic processes played an important role in shaping the potential fungal plant pathogen community assembly in both habitats. Mean annual precipitation and temperature were the most important factor influencing phyllosphere fungal plant pathogen richness. Significantly negative relationships were found between fungal pathogen diversity and sorghum yield. Notably, compared to the rhizosphere, the phyllosphere fungal plant pathogen diversity played a more crucial role in sorghum yield. Together, our work provides novel insights into the factors governing the spatial patterns of fungal plant pathogens in the crop microbiome, and highlights the potential significance of aboveground phyllosphere fungal plant pathogens in crop productivity.


Assuntos
Microbiota , Sorghum , Microbiologia do Solo , Agricultura , Solo , Grão Comestível
7.
Nanotechnology ; 35(4)2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-37871595

RESUMO

A simple hydrothermal method based on an orthogonal experimental design was used to synthesis Pt-loaded TiO2mesoporous nanoparticles in one step. The successful synthesis of Pt-loaded TiO2nanoparticles was demonstrated by various characterization methods. The effects of the modification of Pt and its explanation are described in detail by means of the test results. Through systematic gas-sensing tests, we found that the Pt-loaded TiO2nanoparticles outperform pure TiO2nanoparticles, with a high response value (S= 42.5) to 200 ppm acetone at 260 °C and with a film thickness of 0.45 mm, far superior to that of pure TiO2. The response time (8 s) and recovery time (11 s) of the material are also relatively good with excellent selectivity and long-term stability (30 days). The frequent use of acetone as an organic solution in factories and laboratories, as well as the possibility of making a preliminary diagnosis of diabetes by detecting acetone levels in exhaled gas, make this work promising for environmental monitoring and medical diagnosis.

8.
ISME J ; 17(12): 2182-2189, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37794244

RESUMO

Understanding how antibiotic resistance emerges and evolves in natural habitats is critical for predicting and mitigating antibiotic resistance in the context of global change. Bacteria have evolved antibiotic production as a strategy to fight competitors, predators and other stressors, but how predation pressure of their most important consumers (i.e., protists) affects soil antibiotic resistance genes (ARGs) profiles is still poorly understood. To address this gap, we investigated responses of soil resistome to varying levels of protistan predation by inoculating low, medium and high concentrations of indigenous soil protist suspensions in soil microcosms. We found that an increase in protistan predation pressure was strongly associated with higher abundance and diversity of soil ARGs. High protist concentrations significantly enhanced the abundances of ARGs encoding multidrug (oprJ and ttgB genes) and tetracycline (tetV) efflux pump by 608%, 724% and 3052%, respectively. Additionally, we observed an increase in the abundance of numerous bacterial genera under high protistan pressure. Our findings provide empirical evidence that protistan predation significantly promotes antibiotic resistance in soil bacterial communities and advances our understanding of the biological driving forces behind the evolution and development of environmental antibiotic resistance.


Assuntos
Genes Bacterianos , Solo , Animais , Comportamento Predatório , Microbiologia do Solo , Bactérias/genética , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Eucariotos/genética
9.
FEMS Microbiol Ecol ; 99(11)2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37838473

RESUMO

Soil invertebrates contribute significantly to vital ecosystem functions such as the breakdown of organic matter and cycling of essential nutrients, but our knowledge of their large-scale distribution in agricultural systems is limited, which hinders our ability to robustly predict how they will respond to future global change scenarios. Here, we employed metabarcoding analysis of eukaryotic 18S rRNA genes to examine the diversity and community composition of invertebrates in 528 sorghum rhizosphere and bulk soils, collected from 53 experimental field sites across China. Our results revealed that Nematoda, Arthropoda and Annelida were the dominant soil invertebrate groups in agroecosystems. Among all the climatic and soil parameters we examined, precipitation seasonality (i.e. the irregular distribution of precipitation during a normal year) had the strongest relationship with the richness of soil invertebrates, with an increase in soil invertebrate richness predicted with increasing precipitation seasonality. Mean annual precipitation and soil pH were the most important predictors of soil invertebrate community structure, with numerous invertebrate phylotypes showing either significantly positive or negative relationships with these two variables. Our findings suggest that shifts in precipitation patterns and soil pH, induced by future climate change and agricultural practices, will have important consequences for the distribution of soil invertebrate communities, with implications for agricultural ecosystem sustainability.


Assuntos
Ecossistema , Nematoides , Animais , Solo/química , Nematoides/genética , Mudança Climática , Concentração de Íons de Hidrogênio , Microbiologia do Solo
10.
Appl Environ Microbiol ; 89(9): e0080723, 2023 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-37671870

RESUMO

Complete ammonia oxidizers (comammox Nitrospira) are ubiquitous in coastal wetland sediments and play an important role in nitrification. Our study examined the impact of habitat modifications on comammox Nitrospira communities in coastal wetland sediments across tropical and subtropical regions of southeastern China. Samples were collected from 21 coastal wetlands in five provinces where native mudflats were invaded by Spartina alterniflora and subsequently converted to aquaculture ponds. The results showed that comammox Nitrospira abundances were mainly influenced by sediment grain size rather than by habitat modifications. Compared to S. alterniflora marshes and native mudflats, aquaculture pond sediments had lower comammox Nitrospira diversity, lower clade A.1 abundance, and higher clade A.2 abundance. Sulfate concentration was the most important factor controlling the diversity of comammox Nitrospira. The response of comammox Nitrospira community to habitat change varied significantly by location, and environmental variables accounted for only 11.2% of the variations in community structure across all sites. In all three habitat types, dispersal limitation largely controlled the comammox Nitrospira community assembly process, indicating the stochastic nature of these sediment communities in coastal wetlands. IMPORTANCE Comammox Nitrospira have recently gained attention for their potential role in nitrification and nitrous oxide (N2O) emissions in soil and sediment. However, their distribution and assembly in impacted coastal wetland are poorly understood, particularly on a large spatial scale. Our study provides novel evidence that the effects of habitat modification on comammox Nitrospira communities are dependent on the location of the wetland. We also found that the assembly of comammox Nitrospira communities in coastal wetlands was mainly governed by stochastic processes. Nevertheless, sediment grain size and sulfate concentration were identified as key variables affecting comammox Nitrospira abundance and diversity in coastal sediments. These findings are significant as they advance our understanding of the environmental adaptation of comammox Nitrospira and how future landscape modifications may impact their abundance and diversity in coastal wetlands.


Assuntos
Bactérias , Áreas Alagadas , Oxirredução , Nitrificação , Amônia , China , Archaea , Filogenia
12.
Front Neurol ; 14: 1192756, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37538256

RESUMO

Background and objective: Cerebrocardiac syndrome (CCS) is a severe complication of severe traumatic brain injury (sTBI) that carries high mortality and disability rates. Early identification of CCS poses a significant clinical challenge. The main objective of this study was to investigate potential risk factors associated with the development of secondary CCS in patients with sTBI. It was hypothesized that elevated right heart Tei index (TI), lower Glasgow Coma Scale (GCS) scores, and elevated cardiac troponin-I (cTnI) levels would independently contribute to the occurrence of CCS in sTBI patients. Methods: A retrospective cohort study was conducted to identify risk factors for CCS secondary to sTBI. One hundred and fifty-five patients were enrolled with sTBI admitted to the hospital between January 2016 and December 2020 and divided them into a CCS group (n = 75) and a non-CCS group (n = 80) based on the presence of CCS. This study involved the analysis and comparison of clinical data from two patient groups, encompassing demographic characteristics, peripheral oxygen saturation (SPO2), neuron-specific enolase (NSE), cardiac troponin-I (cTnI), N-terminal pro-brain natriuretic peptide (NT-proBNP), optic nerve sheath diameter (ONSD), cardiac ultrasound, acute physiology and chronic health evaluation (APACHE II) scores, and GCS scores and so on. Multivariate logistic regression was employed to identify independent risk factors for CCS, and receiver operating characteristic (ROC) curves were used to assess their predictive value for CCS secondary to sTBI. Results: The study revealed that 48.4% of sTBI patients developed secondary CCS. In the multivariate analysis model 1 that does not include NT-proBNP and cTnI, ONSD (OR = 2.582, 95% CI: 1.054-6.327, P = 0.038), right heart Tei index (OR = 2.81, 95% CI: 1.288-6.129, P = 0.009), and GCS (OR = 0.212, 95% CI: 0.086-0.521, P = 0.001) were independent risk factors for secondary CCS in sTBI patients. In multivariate analysis model 2 that includes NT-proBNP and cTnI, cTnI (OR = 27.711, 95%CI: 3.086-248.795, P = 0.003), right heart Tei index (OR = 2.736, 95% CI: 1.056-7.091, P = 0.038), and GCS (OR = 0.147, 95% CI: 0.045-0.481, P = 0.002) were independent risk factors for secondary CCS in sTBI patients. The area under the ROC curve for ONSD, Tei index, GCS, and cTnI were 0.596, 0.613, 0.635, and 0.881, respectively. ONSD exhibited a positive predictive value (PPV) of 0.704 and a negative predictive value (NPV) of 0.634. The Tei index demonstrated a PPV of 0.624 and an NPV of 0.726, while GCS had a PPV of 0.644 and an NPV of 0.815. On the other hand, cTnI exhibited a significantly higher PPV of 0.936 and an NPV of 0.817. These findings indicate that the Tei index, GCS score, and cTnI possess certain predictive value for secondary CCS in patients with sTBI. Conclusions: The study provides valuable insights into the identification of independent risk factors for CCS secondary to sTBI. The findings highlight the significance of right heart Tei index, GCS score, and cTnI as potential predictive factors for CCS in sTBI patients. Further larger-scale studies are warranted to corroborate these findings and to provide robust evidence for the development of early intervention strategies aimed at reducing the incidence of CCS in this patient population.

13.
Nat Protoc ; 18(8): 2558-2578, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37479826

RESUMO

Mass spectrometry imaging (MSI) enables the chemical mapping of molecules and elements in a label-free, high-throughput manner. Because this approach can be accomplished rapidly, it also enables chemical changes to be monitored. Here, we describe a protocol for MSI with subcellular spatial resolution. This is achieved by using a microlensed fiber, which is made by grinding an optical fiber. It is a universal and economic technique that can be adapted to most laser-based mass spectrometry methods. In this protocol, the output of laser radiation from the microlensed fiber causes laser ablation of the sample, and the resulting plume is mass spectrometrically analyzed. The microlensed fiber can be used with matrix-assisted laser desorption ionization, laser desorption ionization, laser ablation electrospray desorption ionization and laser ablation inductively coupled plasma, in each case to achieve submicroscale imaging of single cells and biological tissues. This report provides a detailed introduction of the microlensed fiber design and working principles, sample preparation, microlensed fiber ion source setup and multiple MSI platforms with different kinds of mass spectrometers. A researcher with a little background (such as a trained graduate student) is able to complete all the steps for the experimental setup in ~2 h, including fiber test, laser coupling and ion source modification. The imaging time spent mainly depends on the size of the imaging area. It is suggested that most existing laser-based MSI platforms, especially atmospheric pressure applications, can achieve breakthroughs in spatial resolution by introducing a microlensed fiber module.


Assuntos
Diagnóstico por Imagem , Lasers , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Espectrofotometria , Espectrometria de Massas por Ionização por Electrospray/métodos
14.
Microb Biotechnol ; 16(8): 1623-1628, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37354042

RESUMO

Hydrogen-oxidising bacteria play a key role in maintaining the composition of gases within the atmosphere and are ubiquitous in agricultural soils. While studies have shown that hydrogen accumulates in soil surrounding legume nodules and the soil surface, soils as a whole act as a net sink for hydrogen, raising questions about how hydrogen is internally recycled by soils. Can the energy derived from hydrogen oxidation be directly funnelled into plants to promote their growth or does it only act as a booster for other plant-growth promoting bacteria? Moreover, while the fertilisation effect of hydrogen on plants has previously been shown to be beneficial, questions remain about the upper limit of hydrogen uptake by plants before it becomes detrimental. Agricultural practices such as fertilisation may impact the balance of hydrogen-oxidisers and hydrogen-producers in these ecosystems, potentially having detrimental effects on not only agricultural land but also global biogeochemical cycles. In this perspectives piece, we highlight the importance of understanding the contribution of hydrogen to agricultural soils and the effects of agricultural practices on the ability for bacteria to cycle hydrogen in agricultural soils. We propose a framework to gain better insights into microbial hydrogen cycling within agroecosystems, which could contribute to the development of new agricultural biotechnologies.


Assuntos
Ecossistema , Hidrogênio , Microbiologia do Solo , Agricultura , Plantas , Solo/química , Bactérias/genética
16.
ORL J Otorhinolaryngol Relat Spec ; 85(3): 128-140, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37019094

RESUMO

BACKGROUND: Chronic rhinosinusitis (CRS) is a common inflammatory disease in otolaryngology, mainly manifested as nasal congestion, nasal discharge, facial pain/pressure, and smell disorder. CRS with nasal polyps (CRSwNP), an important phenotype of CRS, has a high recurrence rate even after receiving corticosteroids and/or functional endoscopic sinus surgery. In recent years, clinicians have focused on the application of biological agents in CRSwNP. However, it has not reached a consensus on the timing and selection of biologics for the treatment of CRS so far. SUMMARY: We reviewed the previous studies of biologics in CRS and summarized the indications, contraindications, efficacy assessment, prognosis, and adverse effects of biologics. Also, we evaluated the treatment response and adverse reactions of dupilumab, omalizumab, and mepolizumab in the management of CRS and made recommendations. KEY MESSAGES: Dupilumab, omalizumab, and mepolizumab have been approved for the treatment of CRSwNP by the US Food and Drug Administration. Type 2 and eosinophilic inflammation, need for systemic steroids or contraindication to systemic steroids, significantly impaired quality of life, anosmia, and comorbid asthma are required for the use of biologics. Based on current evidence, dupilumab has the prominent advantage in improving quality of life and reducing the risk of comorbid asthma in CRSwNP among the approved monoclonal antibodies. Most patients tolerate biological agents well in general with few major or severe adverse effects. Biologics have provided more options for severe uncontrolled CRSwNP patients or patients who refuse to have surgery. In the future, more novel biologics will be assessed in high-quality clinical trials and applied clinically.


Assuntos
Asma , Produtos Biológicos , Pólipos Nasais , Rinite , Sinusite , Humanos , Asma/tratamento farmacológico , Produtos Biológicos/uso terapêutico , Doença Crônica , Consenso , Pólipos Nasais/complicações , Pólipos Nasais/tratamento farmacológico , Omalizumab/uso terapêutico , Qualidade de Vida , Rinite/complicações , Rinite/tratamento farmacológico , Sinusite/complicações , Sinusite/tratamento farmacológico , Esteroides/uso terapêutico
18.
Micromachines (Basel) ; 14(3)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36984991

RESUMO

Crystallization often occurs in the processing of amorphous alloys, causing the materials lose their excellent properties. The study adopts chemical mechanical polishing of amorphous alloys, presenting the effect of the rotational speed of the polishing turntable, size of abrasive, polishing pressure, and oxidant concentration. The Taguchi method is used to find the best processing parameters, and AFM is used to characterize the machined material surface. At the same time, XPS is used to detect the change of oxide film composition with the addition of oxidant. The results indicate the optimum process parameters: rotational speed of the polishing turntable is 75 r/min, polishing pressure is 28.3 kPa, the size of abrasive is 0.5 µm, and the size of abrasive is a significant factor affecting surface roughness Sa. In addition, as the size of abrasive increases, the material removal rate increases while the surface roughness Sa increases. At pH 10, with an abrasive particle size of 0.5 µm, as the H2O2 concentration increases, the MRR first rapidly decreases at 0.21 wt.% H2O2, and then gradually increases, while the Sa decreases. Furthermore, with the addition of oxidant, the main composition of the surface oxide film changes from oxide to hydroxide, and the contents of Zr4+ and Cu0/Cu1+ elements increase. The findings can provide a feasible chemical mechanical polishing process for zirconium-based amorphous alloys to obtain a satisfactory polishing effect.

20.
FEMS Microbiol Ecol ; 99(4)2023 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-36945103

RESUMO

Deciphering the local diversity and community composition of plant-associated microorganisms is crucial to predict their ecological functions in forest ecosystems. The differences in microbial diversity and community composition between the aboveground and belowground tree compartments remain largely unknown. Here, we examined bacterial communities in the leaf surface (phyllosphere) and root-associated (root and rhizospheric soil) habitats of 13 tree species. Bacterial richness substantially differed across the three compartments, with the highest value observed in rhizospheric soil. Tree species exerted a significant effect on α-diversity of leaf- and soil- but not root-inhabiting bacteria. Bacterial communities were distinct across habitats and were significantly more divergent in leaf- than in root-associated habitats. Leaf nutrients and soil pH and NH4+-N were the main factors regulating leaf- and root-related community composition, respectively. This study highlights that host selection effects on bacterial community structure were more prominent in aboveground than in belowground habitats. Our findings contribute to a better understanding of the effect of compartments and subtropical tree species on microbial diversity, with crucial implications for sustainable forest plantation management.


Assuntos
Ecossistema , Árvores , Solo/química , Plantas , Bactérias/genética , Microbiologia do Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...