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1.
J Virol ; 98(7): e0055624, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38888347

RESUMO

Enterovirus D68 (EV-D68) is a picornavirus associated with severe respiratory illness and a paralytic disease called acute flaccid myelitis in infants. Currently, no protective vaccines or antivirals are available to combat this virus. Like other enteroviruses, EV-D68 uses components of the cellular autophagy pathway to rewire membranes for its replication. Here, we show that transcription factor EB (TFEB), the master transcriptional regulator of autophagy and lysosomal biogenesis, is crucial for EV-D68 infection. Knockdown of TFEB attenuated EV-D68 genomic RNA replication but did not impact viral binding or entry into host cells. The 3C protease of EV-D68 cleaves TFEB at the N-terminus at glutamine 60 (Q60) immediately post-peak viral RNA replication, disrupting TFEB-RagC interaction and restricting TFEB transport to the surface of the lysosome. Despite this, TFEB remained mostly cytosolic during EV-D68 infection. Overexpression of a TFEB mutant construct lacking the RagC-binding domain, but not the wild-type construct, blocks autophagy and increases EV-D68 nonlytic release in H1HeLa cells but not in autophagy-defective ATG7 KO H1HeLa cells. Our results identify TFEB as a vital host factor regulating multiple stages of the EV-D68 lifecycle and suggest that TFEB could be a promising target for antiviral development against EV-D68. IMPORTANCE: Enteroviruses are among the most significant causes of human disease. Some enteroviruses are responsible for severe paralytic diseases such as poliomyelitis or acute flaccid myelitis. The latter disease is associated with multiple non-polio enterovirus species, including enterovirus D68 (EV-D68), enterovirus 71, and coxsackievirus B3 (CVB3). Here, we demonstrate that EV-D68 interacts with a host transcription factor, transcription factor EB (TFEB), to promote viral RNA(vRNA) replication and regulate the egress of virions from cells. TFEB was previously implicated in the viral egress of CVB3, and the viral protease 3C cleaves TFEB during infection. Here, we show that EV-D68 3C protease also cleaves TFEB after the peak of vRNA replication. This cleavage disrupts TFEB interaction with the host protein RagC, which changes the localization and regulation of TFEB. TFEB lacking a RagC-binding domain inhibits autophagic flux and promotes virus egress. These mechanistic insights highlight how common host factors affect closely related, medically important viruses differently.


Assuntos
Autofagia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Enterovirus Humano D , Infecções por Enterovirus , Replicação Viral , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Humanos , Enterovirus Humano D/fisiologia , Enterovirus Humano D/metabolismo , Enterovirus Humano D/genética , Infecções por Enterovirus/metabolismo , Infecções por Enterovirus/virologia , Proteases Virais 3C/metabolismo , Lisossomos/metabolismo , RNA Viral/metabolismo , RNA Viral/genética , Proteínas Virais/metabolismo , Proteínas Virais/genética , Mielite/metabolismo , Mielite/virologia , Ligação Proteica , Células HEK293 , Doenças Neuromusculares , Viroses do Sistema Nervoso Central
2.
Anal Chem ; 96(10): 4197-4204, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38420929

RESUMO

Herein, a method was developed to measure the ammonia oxidation rate (Ra) and the nitrite oxidation rate (Rn) of water and sediment samples using a coupled stable isotope tracing and sulfamic acid reduction (SIT-SAR) method. 15NH4+ was used as a tracer to determine the ammonia oxidation rates (Ra) by calculating the concentrations of produced 15NO2- and 15NO3- during incubation, while 15NO2- was used as a tracer to determine the nitrite oxidation rates (Rn) by calculating the increase of 15NO3- during incubation. 15NO2- was chemically reduced to 29N2 with 15 mmol·L-1 sulfamic acid (SA). 15NO3- was first reduced to 15NO2- with a zinc-cadmium reducing agent, and then 15NO2- was subsequently reduced to 29N2 with SA. The produced 29N2 was measured by a membrane inlet mass spectrometer (MIMS). Under optimized experimental conditions, this method provides a sensitive (detection limit: 0.5 µmol·L-1) and precise (relative standard deviation: 4.80% for 15NO2-, 3.82% for 15NO3-) approach to quantify the concentrations of 15NO2- (0.5-150 µmol·L-1) and 15NO3- (0.5-120 µmol·L-1) in water and sediment samples over a wide range of salinities (0-30‰) with excellent calibration curves (R2 ≥ 0.999). This method was a successful application to estuarine water and sediments along the salinity gradient. Overall, the SIT-SAR method provided a rapid, accurate, and cost-effective means to determine Ra and Rn simultaneously.

3.
Eur Radiol ; 34(2): 745-754, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37589899

RESUMO

OBJECTIVE: To investigate whether the feeding artery (FA) feature can aid in discriminating small hepatocellular carcinoma (HCC) using the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) from precancerous lesions. METHODS: Between June 2017 and May 2021, a total of 347 patients with 351 precancerous liver lesions or small HCCs who underwent CEUS were enrolled. Two independent radiologists assigned LI-RADS categories to all lesions and assessed the presence of the FA feature, which was used as an ancillary feature to either upgrade or downgrade the LI-RADS category. The diagnostic performance of CEUS LI-RADS, both with and without the FA feature, was evaluated based on accuracy, sensitivity, specificity, positive predictive value, and negative predictive value. RESULTS: The FA feature was found to be more prevalent in HCC (85.54%, p < 0.001) than in regenerative nodules (RNs, 29.73%), low-grade dysplastic nodules (LGDNs, 33.33%), and high-grade dysplastic nodules (HGDNs, 55.26%). Furthermore, the presence of arterial phase hyperenhancement (APHE), washout (WO), and FA in liver nodules was associated with a higher expression of GPC-3 and Ki-67 compared to the group without these features (p < 0.001). After adjusting, the sensitivity and accuracy of LR-5 for HCC improved from 68.67% (95%CI: 62.46%, 74.30%) to 77.51% (95%CI: 71.72%, 82.44%) and from 69.23% (95%CI: 64.11%, 74.02%) to 73.79% (95%CI: 68.86%, 78.31%), respectively. CONCLUSION: The FA feature is a valuable feature for distinguishing small HCC and precancerous lesions and could be added as a possible ancillary feature in CEUS LI-RADS which was backed up by biomarkers. CLINICAL RELEVANCE STATEMENT: The presence of a feeding artery is a valuable imaging feature in the differentiation of HCC and precancerous lesions. Incorporating this characteristic in the CEUS LI-RADS can enhance the diagnostic ability. KEY POINTS: • Feeding artery is more frequent in HCC than in regenerative nodules, low-grade dysplastic nodules, and high-grade dysplastic nodules. • Feeding artery feature is a valuable ancillary feature for CEUS LI-RADS to differentiate regenerative nodules, low-grade dysplastic nodules, high-grade dysplastic nodules, and HCC. • The existence of feeding artery, arterial phase hyperenhancement, and washout is associated with more GPC-3 positive expression and higher Ki-67 expression than the group without these features.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Lesões Pré-Cancerosas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Antígeno Ki-67 , Meios de Contraste/farmacologia , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Artérias/patologia , Hiperplasia/patologia , Lesões Pré-Cancerosas/patologia , Sensibilidade e Especificidade
4.
Microb Ecol ; 86(2): 1164-1175, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36502425

RESUMO

Numerous rare species coexist with a few abundant species in microbial communities and together play an essential role in riparian ecosystems. Relatively little is understood, however, about the nature of assembly processes of these communities and how they respond to a fluctuating environment. In this study, drivers controlling the assembly of abundant and rare subcommunities for bacteria and archaea in a riparian zone were determined, and their resulting patterns on these processes were analyzed. Abundant and rare bacteria and archaea showed a consistent variation in the community structure along the riparian elevation gradient, which was closely associated with flooding frequency. The community assembly of abundant bacteria was not affected by any measured environmental variables, while soil moisture and ratio of submerged time to exposed time were the two most decisive factors determining rare bacterial community. Assembly of abundant archaeal community was also determined by these two factors, whereas rare archaea was significantly associated with soil carbon-nitrogen ratio and total carbon content. The assembly process of abundant and rare bacterial subcommunities was driven respectively by dispersal limitation and variable selection. Undominated processes and dispersal limitation dominated the assembly of abundant archaea, whereas homogeneous selection primarily driven rare archaea. Flooding may therefore play a crucial role in determining the community assembly processes by imposing disturbances and shaping soil niches. Overall, this study reveals the assembly patterns of abundant and rare communities in the riparian zone and provides further insight into the importance of their respective roles in maintaining a stable ecosystem during times of environmental perturbations.


Assuntos
Ecossistema , Microbiota , Solo , Microbiologia do Solo , Bactérias/genética , Archaea , Carbono
5.
Int J Hyperthermia ; 40(1): 2181843, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36854449

RESUMO

BACKGROUND: The range of an ablation zone (AZ) plays a crucial role in the treatment effect of microwave ablation (MWA). The aim of this study was to analyze the factors influencing the AZ range. METHODS: Fourteen factors in four areas were included: patient-related factors (sex, age), disease-related factors (tumor location, liver cirrhosis), serological factors (ALT, AST, total protein, albumin, total bilirubin, direct bilirubin, and platelets), and MWA parameters (ablation time, power, and needle type). Multiple sequence MRI was used to delineate AZ by three radiologists using 3D Slicer. MATLAB was used to calculate the AZ length, width, and area of the largest section. Linear regression analysis was used to analyze influencing factors. Moreover, a subgroup analysis was conducted for patients with viral hepatitis. RESULT: 220 patients with 290 tumors were included between 2010-2021. In addition to MWA parameters, cirrhosis and tumor location were significant factors that influenced AZ (p < 0.001). The standardized coefficient (beta) of cirrhosis (cirrhosis vs. non-cirrhosis) was positive, which meant cirrhosis would lead to a decrease in AZ range. The beta of tumor location (near the hepatic hilar zone, intermediate zone, and periphery zone) was negative, indicating that AZ range decreased as the tumor location approached the hepatic hilum. For viral hepatitis patients, Fibrosis 4 (FIB4) score was a significant factor influencing AZ (p < 0.001), and the beta was negative, indicating that AZ range decreased as FIB4 increased. CONCLUSION: Liver cirrhosis, tumor location, and FIB4 affect the AZ range and should be considered when planning MWA parameters.


Assuntos
Cirrose Hepática , Micro-Ondas , Humanos , Micro-Ondas/uso terapêutico , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/cirurgia , Bilirrubina , Plaquetas , Agulhas
6.
J Ultrasound Med ; 42(12): 2825-2838, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37713625

RESUMO

OBJECTIVES: To compare the on-site diagnostic performance of contrast-enhanced ultrasound (CEUS), computed tomography (CECT), and magnetic resonance imaging (CEMRI) for hepatocellular carcinoma (HCC) across diverse practice settings. METHODS: Between May 2019 and April 2022, a total of 2085 patients with 2320 pathologically confirmed focal liver lesions (FLLs) were enrolled. Imaging reports were compared with results from pathology analysis. Diagnostic performance was analyzed in defined size, high-risk factors for HCC, and hospital volume categories. RESULTS: Three images achieved similar diagnostic performance in classifying HCC from 16 types of FLLs, including HCC ≤2.0 cm. For HCC diagnosis at low-volume hospitals and HCC with high-risk factors, the accuracy and specificity of CEUS were comparable to CECT and CEMRI, while the sensitivity of CEUS (77.4 and 89.5%, respectively) was inferior to CEMRI (87.0 and 92.8%, respectively). The diagnostic accuracy of CEUS + CEMRI and CEUS + CECT increased by 7.8 and 6.2% for HCC ≤2.0 cm, 8.0 and 5.0% for HCC with high-risk factors, and 7.4 and 5.5% for HCC at low-volume hospitals, respectively, compared with CEMRI/CECT alone. CONCLUSIONS: Compared with CECT and CEMRI, CEUS provides adequate diagnostic performance in clinical first-line applications at high-volume hospitals. Moreover, a higher diagnostic performance for HCC is achieved by combining CEUS with CECT/CEMRI compared with any single imaging technique.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Meios de Contraste , Ultrassonografia/métodos , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos
7.
Sensors (Basel) ; 23(5)2023 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-36905041

RESUMO

It is crucial to monitor the status of aquaculture objects in recirculating aquaculture systems (RASs). Due to their high density and a high degree of intensification, aquaculture objects in such systems need to be monitored for a long time period to prevent losses caused by various factors. Object detection algorithms are gradually being used in the aquaculture industry, but it is difficult to achieve good results for scenes with high density and complex environments. This paper proposes a monitoring method for Larimichthys crocea in a RAS, which includes the detection and tracking of abnormal behavior. The improved YOLOX-S is used to detect Larimichthys crocea with abnormal behavior in real time. Aiming to solve the problems of stacking, deformation, occlusion, and too-small objects in a fishpond, the object detection algorithm used is improved by modifying the CSP module, adding coordinate attention, and modifying the part of the structure of the neck. After improvement, the AP50 reaches 98.4% and AP50:95 is also 16.2% higher than the original algorithm. In terms of tracking, due to the similarity in the fish's appearance, Bytetrack is used to track the detected objects, avoiding the ID switching caused by re-identification using appearance features. In the actual RAS environment, both MOTA and IDF1 can reach more than 95% under the premise of fully meeting real-time tracking, and the ID of the tracked Larimichthys crocea with abnormal behavior can be maintained stably. Our work can identify and track the abnormal behavior of fish efficiently, and this will provide data support for subsequent automatic treatment, thus avoiding loss expansion and improving the production efficiency of RASs.


Assuntos
Perciformes , Animais , Peixes , Aquicultura/métodos
8.
Int J Hyperthermia ; 39(1): 595-604, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35435082

RESUMO

OBJECTIVE: To develop and validate an ultrasonic radiomics model for predicting the recurrence and differentiation of hepatocellular carcinoma (HCC). Convolutional neural network (CNN) ResNet 18 and Pyradiomics were used to analyze gray-scale-ultrasonic images to predict the prognosis and degree of differentiation of HCC. METHODS: This retrospective study enrolled 513 patients with HCC who underwent preoperative grayscale-ultrasonic imaging, and their clinical characteristics were observed. Patients were randomly divided into training (n = 413) and validation (n = 100) cohorts. CNN ResNet 18 and Pyradiomics were used to analyze ultrasonic images of HCC and peritumoral images to develop a prognostic and differentiation model. Clinical characteristics were integrated into the radiomics model and patients were stratified into high- and low-risk groups. The predictive effect was evaluated using the C-index and receiver operating characteristic (ROC) curve. RESULTS: The model combined with ResNet 18 and clinical characteristics achieved a good predictive ability. The C-indices of early recurrence (ER), late recurrence (LR), and recurrence-free survival (RFS) were 0.695 (0.561-0.789), 0.715 (0.623-0.800) and 0.721 (0.647-0.795), respectively, in the validation cohort, which was superior to the clinical model and ultrasonic semantic model. The model could stratify patients into high- and low-risk groups, which showed significant differences (p < 0.001) in ER, LR, and RFS. The area under the curve for predicting the degree of HCC differentiation was 0.855 and 0.709 in the training and validation cohorts, respectively. CONCLUSION: We developed and validated a radiomics model to predict HCC recurrence and HCC differentiation, which could also acquire pathological information in a noninvasive manner.KEY RESULTSA hepatocellular carcinoma (HCC) prognostic prediction model was developed and validated by convolutional neural network (CNN) ResNet 18-based gray-scale ultrasound (US).A differentiation of HCC prediction model was developed for preoperative prediction avoiding invasive operation.Compared with Pyradiomics, CNN ResNet was more suitable for extracting information from US images.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Micro-Ondas , Estudos Retrospectivos , Ultrassonografia
9.
Curr Microbiol ; 79(10): 289, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35972698

RESUMO

Denitrifying bacteria, playing a key role in nitrogen removal in ecosystem, are highly diverse and complex in their community composition. However, there were few reports on the abundance, community composition, and the contribution to nitrogen loss of denitrifiers in natural acidic red soils. In this study, we investigated the structure and function of nirS-type denitrifying bacteria in ten natural red soil samples collected from nine provinces in southern China, based on quantitative polymerase chain reaction (qPCR) and high-throughput sequencing techniques. Nitrogen loss from microbial denitrification in red soils of southern China was estimated up to 9.86 Tg N per year based on 15N isotope tracing method. The abundance of nirS-type denitrifiers varied from 8.41 × 105 to 2.55 × 109 copies per gram of dry weight. The community of nirS-type denitrifying bacterial was revealed, which contained 50 dominant OTUs assigned to 9 clusters phylogenetically related to Marinobacter, Rhodobacter, and other uncultured species. pH was the key factor affecting both denitrification rates and community composition. Our results demonstrate that nirS-type denitrifying bacteria have higher abundance, diversity, and contribution to the nitrogen loss in natural acidic red soils of southern China.


Assuntos
Nitrogênio , Solo , Bactérias/genética , Desnitrificação , Ecossistema , Solo/química , Microbiologia do Solo
10.
PLoS Pathog ; 15(6): e1007819, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31194843

RESUMO

Recently identified broadly neutralizing antibodies (bnAbs) show great potential for clinical interventions against HIV-1 infection. However, resistant strains may impose substantial challenges. Here, we report on the identification and characterization of a panel of HIV-1 strains with broad and potent resistance against a large number of bnAbs, particularly those targeting the CD4-binding site (CD4bs). Site-directed mutagenesis revealed that several key epitope mutations facilitate resistance and are located in the inner domain, loop D, and ß23/loop V5/ß24 of HIV-1 gp120. The resistance is largely correlated with binding affinity of antibodies to the envelope trimers expressed on the cell surface. Our results therefore demonstrate the existence of broadly resistant HIV-1 strains against CD4bs neutralizing antibodies. Treatment strategies based on the CD4bs bnAbs must overcome such resistance to achieve optimal clinical outcomes.


Assuntos
Anticorpos Neutralizantes/imunologia , Antígenos CD4/imunologia , Epitopos/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Anticorpos Neutralizantes/genética , Antígenos CD4/genética , Linhagem Celular , Epitopos/genética , Anticorpos Anti-HIV/genética , Proteína gp120 do Envelope de HIV/genética , HIV-1/genética , Humanos
11.
Microb Cell Fact ; 20(1): 118, 2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34147119

RESUMO

Lactic acid bacteria (LAB) are a phylogenetically diverse group with the ability to convert soluble carbohydrates into lactic acid. Many LAB have a long history of safe use in fermented foods and are recognized as food-grade microorganisms. LAB are also natural inhabitants of the human intestinal tract and have beneficial effects on health. Considering these properties, LAB have potential applications as biotherapeutic vehicles to delivery cytokines, antigens and other medicinal molecules. In this review, we summarize the development of, and advances in, genome manipulation techniques for engineering LAB and the expected future development of such genetic tools. These methods are crucial for us to maximize the value of LAB. We also discuss applications of the genome-editing tools in enhancing probiotic characteristics and therapeutic functionalities of LAB.


Assuntos
Biotecnologia/métodos , Sistemas de Liberação de Medicamentos , Alimentos Fermentados/microbiologia , Edição de Genes/métodos , Melhoramento Genético/métodos , Lactobacillales/genética , Microbiologia de Alimentos , Humanos , Intestinos/microbiologia , Probióticos
12.
Ecotoxicology ; 30(8): 1743-1753, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32951159

RESUMO

In natural habitats, the diversity of anaerobic ammonia-oxidizing (anammox) bacteria could be affected by multiple environmental variables. In this study, we investigated the distribution of the anammox bacterial community in surface sediment from the Dongjiang River (riverine sediment, DJ) to the Pearl River Estuary (estuarine sediment, PRE) and then to the South China Sea (coastal sediment, SCS). The results revealed evident differences in the structural diversity of anammox bacteria in three different habitats. Candidatus Brocadia accounted for approximately 90% of the total anammox bacteria in DJ, conversely, Ca. Scalindua dominated in the SCS. Nevertheless, Ca. Scalindua, Ca. Brocadia and Ca. Kuenenia coexisted in the PRE. The qPCR results indicated that anammox bacterial 16S rRNA gene abundance ranged from 2.23 × 105 to 1.19 × 107 copies g-1 of wet weight, but no significant correlation was found between the abundances and environmental variables (p > 0.05). The relative abundances of Ca. Brocadia gradually decreased with increasing salinity, and Ca. Scalindua showed the opposite trend, suggesting that salinity was a crucial factor in sculpturing the community composition of anammox bacteria in natural environments. Ca. Brocadia should be able to live in freshwater ecosystems, but it can also tolerate a certain level of salinity. Ca. Scalindua was halophilic anammox bacterium and exists only in saline environments. Ca. Kuenenia could adapt to a wide range of salinity and preferred to live in high DIN level conditions according to our search. The distribution pattern of anammox bacteria may be the result of microbial migration and long-term adaptation to salinity.


Assuntos
Compostos de Amônio , Rios , Amônia , Anaerobiose , Biodiversidade , Ecossistema , Oceanos e Mares , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Salinidade
13.
Ecotoxicology ; 30(8): 1689-1703, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33411163

RESUMO

Dissimilatory nitrate reduction to ammonia (DNRA) process, competing with denitrification and anaerobic ammonia oxidation (anammox) for nitrate, is an important nitrogen retention pathway in the environment. Previous studies on DNRA bacterial diversity and composition focused on the surface sediments in estuaries, but studies on the deep sediments are limited, and the linkage between DNRA community structure and complex estuarine environment remains unclear. In this study, through high-throughput sequencing of nrfA gene followed by high-resolution sample inference, we examined spatially and temporally the composition and diversity of DNRA bacteria along a salinity gradient in five sediment cores of the Pearl River Estuary (PRE). We found a higher diversity and richness of DNRA bacteria in sediments with lower organic carbon, where sea water intersects fresh water. Moreover, the DNRA bacterial communities had the specific spatially distribution coupling with their metabolic difference along the salinity gradient of the Pearl River Estuary, but no obvious difference along the sediment depth. The distribution of DNRA bacteria in the PRE was largely driven by various environmental factors, including salinity, Oxidation-Reduction Potential (ORP), ammonium, nitrate and Corg/NO3-. Furthermore, dominant DNRA bacteria were found to be the key populations of DNRA communities in the PRE sediments by network analysis. Collectively, our results showed that niche difference of DNRA bacteria indeed occurs in the Pearl River Estuary.


Assuntos
Estuários , Nitratos , Amônia , Bactérias/genética , Desnitrificação , Sedimentos Geológicos , Nitratos/análise , Nitrogênio/análise , Oxirredução , Rios
14.
Environ Res ; 182: 109083, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31901627

RESUMO

Freshwater ecosystems are undergoing extensive human disturbance of dam construction which form large amounts of reservoirs and lead to dramatic changes in hydraulic conditions. Bacterioplankton are key component of aquatic ecosystems. Investigation on their taxonomic compositions and associated functions responded to reservoir operation is essential to understand the ecological consequence of dam construction. In this study, we use the Three Gorges Reservoir as a model system. High-throughput sequencing is used to investigate the bacterioplankton community composition, and the bioinformatic tool of Tax4Fun is applied to predict the potential metabolic functions responded to reservoir impoundment. Results show that the taxonomic communities of bacterioplankton are significantly impacted by impoundment. The dominant group of Actinobacteria which accounts for 17.0%-58.1% of the retrieved sequences significantly increases after impoundment on phylum level. The influences of impoundment appear to be more apparent on order level that the relative abundances of four groups including Frankiales, Sphingomonadales, Sphingobacteriales and SubsectionI of class Cyanobacteria significantly vary after impoundment. In contrast, the predicted functional communities of bacterioplankton remain relatively stable that most of predicted functional categories including methane and nitrogen metabolisms have no significant variation after impoundment. Besides, significant distance decay patterns appear on the taxonomic communities after impoundment rather than the predicted functional communities. The environmental variables show significant impacts on the taxonomic community rather than predicted functional community, whereas the spatial variables have no effect on both taxonomic and predicted functional communities. In general, the taxonomic and predicted functional communities of bacterioplankton exhibit divergent responses to the impoundment in reservoir.


Assuntos
Bacteroidetes , Cianobactérias , Ecossistema , Organismos Aquáticos , China , Água Doce , Abastecimento de Água
15.
Appl Microbiol Biotechnol ; 104(22): 9823-9837, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32949277

RESUMO

Preah Vihear temple is one of the most significant representatives of the ancient Angkorian temples listed as United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sites. The surfaces of this Angkor sandstone monument are covered with deteriorated materials, broadly called "sediments" here, resulting from a long time of weathering of the sandstone. The sediments might adversely affect the ancient sandstone substratum of this cultural heritage, and the potential risk from them is essential information for current strategies and on-going protection and management. The extracted DNA from the sediment samples of this temple was used for Illumina high-throughput sequencing analysis, resulting in approximately 12 Gb of metagenomic dataset. The results of this shotgun metagenomic analysis provided a thorough information of the phylogenetic groups presented in the microbiome of the sediment samples, indicating that potential metabolic activities, involving different geomicrobiological cycles, may occur in this microbiome. The phylogenetic result revealed that the majority of metagenomic reads were affiliated with Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes at the phylum level. The metabolic reconstruction results indicated that the important geomicrobiological cycling processes include carbon sequestration, and nitrogen and sulfur transformation as the potentially active ones in the sediments of the sampling sites. Specifically, the dissimilatory nitrate reduction to ammonium (DNRA) and the newly discovered complete ammonia oxidation (comammox) were retrieved from this metagenomic dataset. Furthermore, the genetic information on the presence of acid-producing processes by sulfur- and ammonia-oxidizing bacteria and archaea in this metagenomic dataset suggested that the microbial flora in these samples has the potential to participate in the degradation of sandstone cultural heritage by producing acids. N-15 isotope amendment and incubation analysis results confirmed the presence of active denitrification, but not anammox activity at this temple. These results are important for our knowledge on the microbial community composition and microbial biodeterioration processes affecting this sandstone cultural heritage and will aid in the protection and management of the ancient Preah Vihear temple.Key Points• Microbiota on Preah Viher temple was analyzed using NGS.• Nitrate-N transformation by DNRA, comammox, and denitrifcation was detected.• N-15 isotope analysis confirmed the active denitrifcation, but not Anammox.• Accumulation of nitrate is a result of less active removal by denitrification.


Assuntos
Microbiota , Nitratos , Camboja , Desnitrificação , Metagenômica , Nitratos/análise , Nitrogênio , Isótopos de Nitrogênio , Oxirredução , Filogenia
16.
Appl Microbiol Biotechnol ; 104(22): 9853, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33067684

RESUMO

The published online version contains mistake for the author the authors correction to change the name from Clara Uriz to Clara Urzì was missed.

17.
Sensors (Basel) ; 20(5)2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32131393

RESUMO

Intelligent fault diagnosis algorithms based on machine learning and deep learning techniques have been widely used in industrial applications and have obtained much attention as well as achievements. In real industrial applications, working loads of machines are always changing. Hence, directly applying the traditional algorithms will cause significant degradation of performance with changing conditions. In this paper, a novel domain adaptation method, named generative transfer learning (GTL), is proposed to tackle this problem. First, raw datasets were transformed to time-frequency domain based on short-time Fourier transformation. A domain discriminator was then built to distinguish whether the data came from the source or the target domain. A target domain classification model was finally acquired by the feature extractor and the classifier. Experiments were carried out for the fault diagnosis of a wind turbine gearbox. The t-distributed stochastic neighbor embedding technique was used to visualize the output features for checking the effectiveness of the proposed algorithm in feature extraction. The results showed that the proposed GTL could improve classification rates under various working loads. Compared with other domain adaptation algorithms, the proposed method exhibited not only higher accuracy but faster convergence speed as well.

18.
Appl Microbiol Biotechnol ; 103(20): 8439-8448, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31511933

RESUMO

A ß-galactosidase (ß-GalINF) was directly isolated from feces of an 8-month-old infant. Mass spectrum analysis showed ß-GalINF with coverage over 50% to the ß-galactosidase from Bifidobacterium longum EK3. Accordingly, the ß-galINF was amplified from the feces metagenomic DNA by degenerate primers. After overexpressed in Escherichia coli, the ß-GalINF was purified and biochemical characterized. ß-GalINF existed as homotetramer and homodimer, whose activity (optimal at 50 °C, pH 6.5) was exhilaratingly increased to 484% by artificial intestinal juice. The Km and Vmax values for oNPG and lactose were 20.95 ± 2.76 mM, 5004.50 ± 318.8 µmol min-1 mg-1 and 140.2 ± 17.7 mM, 293.1 ± 14.7 µmol min-1 mg-1, respectively. The production rate of galacto-oligosaccharides by ß-GalINF from 20% lactose at 50 °C was 33.4 ± 0.67%. These results suggested the ß-GalINF with high hydrolytic and transgalactosylation activity from the infant intestinal has great potential as infant lactase preparation. Moreover, this study provided a new way for exploring undetected enzymes by uncultured-dependent methods.


Assuntos
Fezes/enzimologia , beta-Galactosidase/isolamento & purificação , beta-Galactosidase/metabolismo , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Humanos , Concentração de Íons de Hidrogênio , Lactente , Cinética , Espectrometria de Massas , Oligossacarídeos/metabolismo , Multimerização Proteica , Temperatura , beta-Galactosidase/química
19.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(1): 34-39, 2019 Jan.
Artigo em Zh | MEDLINE | ID: mdl-31037902

RESUMO

OBJECTIVE: To determine the effects of electroacupuncture (EA) and intracerebral injection of vascular endothelial growth factor (VEGF) on caspase12, caspase3, and glucose regulated protein 78 kD (GRP78) genes of rats with cerebral ischemia reperfusion injury. METHODS: 60 SD rats were randomly divided into sham-operation group, model group, EA group and EA+VEGF group with 15 rats in each group. Middle cerebral artery occlusion (MCAO) method was used to establish the model of cerebral ischemia reperfusion injury. Electro-acupuncture intervention was introduced 1 day after the injury in the EA group and EA+VEGF group: 30 minutes each session and once a day for a total of 14 d [acupoint selection: Baihui (GV 20), Quchi(Li 11), Zusanli (ST36)]. The rats in the EA+VEGF group were also injected with 10 µL of VEGF165 (0.025 µg/µL) into the lateral ventricle after the first session of EA. Five rats in each group were sacrificed after obtaining a neurological function score (mNSS) at day 0 (1 d after modeling, before EA intervention), day 7 and day 14, respectively. Nissl staining was used to observe the histomorphology of cerebral infarction areas. Immunohistochemistry was used to CM(155mm]detect GRP78 activity in the ischemic brain tissues. Real-time fluorescence quantitative PCR (real-time PCR) was used to detect the expressions of caspase12, caspase3 and GRP78 mRNA in the ischemic brain tissues. RESULTS: Compared with the sham-operation group, rats in the model group had higher mNSS scores ( P<0.05), showed signs of cerebral infarction (with reduced numbers of and disordered Nissl bodies and unclear structure), increased GRP78 immunopositive cells, increased expression of GRP78 mRNA ( P<0.05), and increased expressions of caspase12 and caspase3 mRNA ( P<0.05). Compared with the model group, EA and EA+VEGF decreased mNSS scores at day 7 and 14 ( P<0.05), showing alleviated signs of cerebral infarction, increased GRP78 immunopositive cells ( P<0.05), increased GRP78 mRNA expression ( P<0.05), and decreased caspase12 and caspase3 mRNA expressions ( P<0.05). The most obvious changes were found in the EA+VEGF group ( P<0.05). No significant changes were observed in the sham-operation group over time ( P<0.05). In comparison, mNSS scores, the signs of cerebral infarction, and the expressions of caspase12 and caspase3 decreased over time in the other groups ( P<0.05), accompanied with increased GRP78 immunopositive cells and the expression of GRP78 gene ( P<0.05). CONCLUSION: Electroacupuncture and intracerebral injection of VEGF promote tissue repair of rats with cerebral ischemic injury, possibly through down-regulating the expressions of caspase12 and caspase3 genes and up-regulating the expression of GRP78 gene. The effect of electroacupuncture in combination with intracerebral injection of VEGF is superior to that of the single use of electroacupuncture.


Assuntos
Isquemia Encefálica , Eletroacupuntura , Traumatismo por Reperfusão , Animais , Caspase 12 , Caspase 3 , Proteínas de Choque Térmico , Ratos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular
20.
Chemistry ; 22(41): 14475-9, 2016 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-27553910

RESUMO

Temperature measurements in biology and medical diagnostics, along with sensitive temperature probing of living cells, is of great importance; however, it still faces significant challenges. Herein, a novel "turn-on" carbon-dot-based fluorescent nanothermometry device for spatially resolved temperature measurements in living cells is presented. The carbon nanodots (CNDs) are prepared by a green microwave-assisted method and exhibit red fluorescence (λem =615 nm) with high quantum yields (15 %). Then, an on-off fluorescent probe is prepared for detecting glutathione (GSH) based on aggregation-induced fluorescence quenching. Interestingly, the quenched fluorescence could be recovered by increasing temperature and the CNDs-GSH mixture could behave as an off-on fluorescent probe for temperature. Thus, red-emitting CNDs can be utilized for "turn-on" fluorescent nanothermometry through the fluorescence quenching and recovery processes, respectively. We employ MC3T3-E1 cells as an example model to demonstrate the red-emitting CNDs can function as "non-contact" tools for the accurate measurement of temperature and its gradient inside a living cell.


Assuntos
Carbono/química , Corantes Fluorescentes/química , Nanopartículas/química , Animais , Bioensaio/métodos , Linhagem Celular , Sobrevivência Celular , Glutationa/metabolismo , Química Verde , Camundongos , Micro-Ondas , Tamanho da Partícula , Espectrometria de Fluorescência , Propriedades de Superfície , Temperatura
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