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1.
Anal Chim Acta ; 1307: 342640, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719417

RESUMO

BACKGROUND: The analysis of cell membrane permeability plays a crucial role in improving the procedures of cell cryopreservation, which will affect the specific parameter settings in loading, removal and cooling processes. However, existing studies have mostly focused on deriving permeability parameters through osmotic theoretical models and cell volume response analysis, and there is still a lack of the direct experimental evidence and analysis at the single-cell level regarding the migration of cryoprotectants. RESULTS: In this work, a side perfusion microfluidics chips combined with Raman spectroscopy system was built to monitor in situ the Raman spectroscopy of extracellular and intracellular solution during loading and elution process with different cryoprotectant solution systems (single and dual component). And it was found that loading a high concentration cryoprotectant solution system through a single elution cycle may result in significant residual protective agent, which can be mitigated by employing a multi-component formula but multiple elution operations are still necessary. Furthermore, the collected spectral signals were marked and analyzed to was perform preliminary relative quantitative analysis. The results showed that the intracellular concentration changes can be accurately quantified by the Raman spectrum and are closely related to the extracellular solution concentration changes. SIGNIFICANCE AND NOVELTY: By using the method of small flow perfusion (≤20 µL/min) in the side microfluidic chip after the gravity sedimentation of cells, the continuous loading and elution process of different cryoprotectants on chip and the spectral acquisition can be realized. The intracellular and extracellular concentrations can be quantified in situ based on the ratio of spectral peak intensities. These results indicate that spectroscopic analysis can be used to effectively monitor intracellular cryoprotectant residues.


Assuntos
Crioprotetores , Análise de Célula Única , Análise Espectral Raman , Análise Espectral Raman/métodos , Crioprotetores/química , Crioprotetores/farmacologia , Crioprotetores/isolamento & purificação , Dispositivos Lab-On-A-Chip , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Criopreservação/métodos , Animais
3.
Microb Pathog ; 191: 106640, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38614437

RESUMO

BACKGROUND: Staphylococcus aureus is one of the most prevalent pathogens in bovine mastitis, which leads to substantial financial losses for the dairy industry. RESULTS: In this study, S. aureus (n = 72) was isolated from 18 dairy farms in 15 provinces across China in 2021. The identification of these isolates at the species level was achieved by employing 16S rRNA sequencing. An isothermal amplification method for auxiliary detection of S. aureus was established, which can be employed not only for laboratory detection but also for point-of-care testing (POCT). Molecular characteristics of S. aureus mastitis in Chinese dairy cows were determined through MLST and spa typing. Finally, methicillin-resistant Staphylococcus aureus (MRSA) and MRSA resistance genes were detected using MIC and PCR amplification techniques. 72 isolates were identified as 12 sequence types (STs) and 7 clonal complexes (CC). ST1/CC1 was the dominant prevalent accounting for 33.3 % of the total, and exhibiting a wide distribution range. In terms of spa types, t114 was the dominant type, accounting for 31.9 % of the total, followed by t529 as the second major type. Four S. aureus strains were classified as MRSA according to their levels of oxacillin resistance (MIC ≥4 µg/mL). Among these four MRSA strains, one of them was found to be mecA positive. However, the presence of drug-resistance genes mecA and mecC was not detected in the remaining three MRSA strains, indicating the possible existence of new resistance genes. CONCLUSIONS: Our study investigated the prevalence of S. aureus mastitis in dairy cows in China, while also examined the molecular characteristics and MRSA strains. This information will help with the clinical monitoring, prevention, and control of S. aureus mastitis in dairy cattle.


Assuntos
Antibacterianos , Mastite Bovina , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , RNA Ribossômico 16S , Infecções Estafilocócicas , Staphylococcus aureus , Animais , Bovinos , Mastite Bovina/microbiologia , Mastite Bovina/epidemiologia , China/epidemiologia , Infecções Estafilocócicas/veterinária , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/epidemiologia , Feminino , Staphylococcus aureus/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/classificação , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , RNA Ribossômico 16S/genética , Antibacterianos/farmacologia , Indústria de Laticínios
4.
PLoS Pathog ; 20(4): e1012169, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38640137

RESUMO

Integrative and conjugative elements (ICEs) play a vital role in bacterial evolution by carrying essential genes that confer adaptive functions to the host. Despite their importance, the mechanism underlying the stable inheritance of ICEs, which is necessary for the acquisition of new traits in bacteria, remains poorly understood. Here, we identified SezAT, a type II toxin-antitoxin (TA) system, and AbiE, a type IV TA system encoded within the ICESsuHN105, coordinately promote ICE stabilization and mediate multidrug resistance in Streptococcus suis. Deletion of SezAT or AbiE did not affect the strain's antibiotic susceptibility, but their duple deletion increased susceptibility, mainly mediated by the antitoxins SezA and AbiEi. Further studies have revealed that SezA and AbiEi affect the genetic stability of ICESsuHN105 by moderating the excision and extrachromosomal copy number, consequently affecting the antibiotic resistance conferred by ICE. The DNA-binding proteins AbiEi and SezA, which bind palindromic sequences in the promoter, coordinately modulate ICE excision and extracellular copy number by binding to sequences in the origin-of-transfer (oriT) and the attL sites, respectively. Furthermore, AbiEi negatively regulates the transcription of SezAT by binding directly to its promoter, optimizing the coordinate network of SezAT and AbiE in maintaining ICESsuHN105 stability. Importantly, SezAT and AbiE are widespread and conserved in ICEs harbouring diverse drug-resistance genes, and their coordinated effects in promoting ICE stability and mediating drug resistance may be broadly applicable to other ICEs. Altogether, our study uncovers the TA system's role in maintaining the genetic stability of ICE and offers potential targets for overcoming the dissemination and evolution of drug resistance.


Assuntos
Proteínas de Bactérias , Streptococcus suis , Sistemas Toxina-Antitoxina , Streptococcus suis/genética , Streptococcus suis/efeitos dos fármacos , Sistemas Toxina-Antitoxina/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana Múltipla/genética , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/genética , Antibacterianos/farmacologia , Conjugação Genética , Animais , Sequências Repetitivas Dispersas
6.
Cancer Lett ; 589: 216825, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38548218

RESUMO

As one of the key metabolic enzymes in the glycolytic pathway, lactate dehydrogenase A (LDHA) might be linked to tumor proliferation by driving the Warburg effect. Circular RNAs (circRNAs) are widely implicated in tumor progression. Here, we report that circTATDN3, a circular RNA that interacts with LDHA, plays a critical role in proliferation and energy metabolism in CRC. We found that circTATDN3 expression was increased in CRC cells and tumor tissues and that high circTATDN3 expression was positively associated with poor postoperative prognosis in CRC patients. Additionally, circTATDN3 promoted the proliferation of CRC cells in vivo and vitro. Mechanistically, circTATDN3 was shown to function as an adaptor molecule that enhances the binding of LDHA to FGFR1, leading to increased LDHA phosphorylation and consequently promoting the Warburg effect. Moreover, circTATDN3 increased the expression of LDHA by sponging miR-511-5p, which synergistically promoted CRC progression and the Warburg effect. In conclusion, circTATDN3 may be a target for the treatment of CRC.


Assuntos
Neoplasias Colorretais , MicroRNAs , Humanos , RNA Circular/genética , Linhagem Celular Tumoral , Lactato Desidrogenase 5/genética , Lactato Desidrogenase 5/metabolismo , Neoplasias Colorretais/patologia , Proliferação de Células , MicroRNAs/genética , MicroRNAs/metabolismo , Regulação Neoplásica da Expressão Gênica
7.
J Virol Methods ; 323: 114851, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37956891

RESUMO

With the rapid development of cattle industry, bovine viral diarrhea virus (BVDV) is becoming widespread in China, which causes serious economic losses to the industry. Effective vaccination and viral surveillance are critical for the prevent and control of BVDV infection. In the present study, the immunogenic domain of E2 protein of BVDV-1 was expressed by prokaryotic pET-28a vector. Monoclonal antibodies (mAbs) against E2 protein were prepared and systemically examined by western blot, immunofluorescence assay, blocking ELISA (bELISA) and virus neutralization test (VNT). The mAb 1E2B3, which showed good reactivity and neutralizing activity to BVDV-1 strains, was selected for ELISA establishment. After a series of screening and optimization, a novel bELISA for highly sensitive and specific detection of BVDV-1 antibodies was established, using HRP-labeled 1E2B3 and recombinant E2 protein. ROC analysis of 91 positive and 84 negative reference bovine serum samples yielded the area under the curve (AUC) of 0.9903. A diagnostic specificity of 96.43 % and a sensitivity of 95.6 % were achieved when the cutoff value was set at 24.31 %. There was no cross reaction to the positive sera of classical swine fever virus (CSFV), BVDV-2, border disease virus (BDV), bovine parainfluenza virus type 3 (BPIV3), infectious bovine rhinotracheitis virus (IBRV), foot-and-mouth disease virus (FMDV), Mycoplasma bovis (M.bovis) and Brucella. The total agreement rate of bELISA with VNT was 93.96 % (249/265). In addition, the result of bELISA was positively correlated with neutralizing antibody titer, and the bELISA could well distinguish the serum samples before and after BVDV vaccination. These results indicate that the established bELISA in this study is specific, sensitive, simple and convenient, which provides technical support for the vaccine efficacy evaluation, prevention and control of BVD in the future.


Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina , Vírus da Diarreia Viral Bovina Tipo 1 , Vírus da Diarreia Viral Bovina , Animais , Suínos , Bovinos , Anticorpos Monoclonais , Ensaio de Imunoadsorção Enzimática/métodos , Anticorpos Antivirais , Proteínas Recombinantes , Diarreia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle
8.
Virus Res ; 339: 199204, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-37607596

RESUMO

Circular replication-associated protein (Rep)-encoding single-stranded (CRESS) DNA viruses are highly diverse and have a broad range of hosts. In this study, we report the detection of Bo-Circo-like virus AH20-1 in the feces of diarrheal cattle. The virus has a circular genome of 3,912 nucleotides, three major putative open reading frames, and encodes a Rep gene of 310 amino acids. We found that the virus is closely related to the Bo-Circo-like virus CH strain, which belongs to the novel Kirkoviridae family. Furthermore, we conducted a nationwide surveillance program and found that the virus is prevalent in China (23.6%, 205/868), with the BCLa subtype being the predominant strain. Our findings suggest that the virus can infect sheep, highlighting the potential for cross-species transmission. Our pressure analysis indicates that the CRESS-DNA Kirkoviridae family has broad host adaptation, and that selection pressure played an important role in the evolution of its Rep genes. Our study underscores the need for continued epidemiological surveillance of this virus due to its widespread prevalence in our ruminant population and potential for cross-species transmission.


Assuntos
Animais Domésticos , DNA Viral , Animais , Bovinos , Ovinos , DNA Viral/genética , DNA Viral/química , DNA de Cadeia Simples/genética , Filogenia , Genoma Viral , Vírus de DNA/genética , DNA Circular
9.
Biotechnol J ; 18(12): e2300056, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37688450

RESUMO

BACKGROUND: 7-Dehydrocholesterol (7-DHC) can be directly converted to vitamin D3 by UV irradiation and de novo synthesis of 7-DHC in engineered Saccharomyces cerevisiae has been recognized as an attractive substitution to traditional chemical synthesis. Introduction of sterol extracellular transport pathway for the secretory production of 7-DHC is a promising approach to achieve higher titer and simplify the downstream purification processing. METHODS AND RESULTS: A series of genes involved in ergosterol pathway were combined reinforced and reengineered in S. cerevisiae. A biphasic fermentation system was introduced and 7-DHC was found to be enriched in oil-phase with an increased titer by 1.5-folds. Quantitative PCR revealed that say1, atf2, pdr5, pry1-3 involved in sterol storage and transport were all significantly induced in sterol overproduced strain. To enhance the secretion capacity, lipid transporters of pathogen-related yeast proteins (Pry), Niemann-Pick disease type C2 (NPC2), ATP-binding cassette (ABC)-family, and their homologues were screened. Both individual and synergetic overexpression of Plant pathogenesis Related protein-1 (Pr-1) and Sterol transport1 (St1) largely increased the de novo biosynthesis and secretory productivity of 7-DHC, and the final titer reached 28.2 mg g-1 with a secretion ratio of 41.4%, which was 26.5-folds higher than the original strain. In addition, the cooperation between Pr-1 and St1 in sterol transport was further confirmed by confocal microscopy, molecular docking, and directed site-mutation. CONCLUSION: Selective secretion of different sterol intermediates was characterized in sterol over-produced strain and the extracellular export of 7-DHC developed in present study significantly improved the cell biosynthetic capacity, which offered a novel modification idea for 7-DHC de novo biosynthesis by S. cerevisiae cell factory.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Simulação de Acoplamento Molecular , Desidrocolesteróis/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Esteróis/metabolismo
10.
Microbiol Spectr ; 11(3): e0504022, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37162348

RESUMO

Emerging viruses are a constant threat to human and animal health. Boosepivirus is a novel picornavirus considered a gastrointestinal pathogen and has broken out in recent years. In 2020, we identified a strain of boosepivirus NX20-1 from Chinese calf feces and performed genetic characterization and evolutionary analysis. NX20-1 was closely related to the Japanese strain Bo-12-38/2009/JPN and belonged to Boosepivirus B. We found that 64 of 603 samples (10.6%) from 20 different provinces across the country were positive for boosepivirus by reverse transcription (RT)-PCR. Further, coinfection with other diarrheal pathogens was also present in 35 of these positive samples. Importantly, we found the prevalence of boosepivirus in sheep as well, indicating that Boosepivirus can infect different domestic animals. Our data suggest that boosepivirus is a potential diarrheal pathogen, but the pathogenicity and the mechanism of pathogenesis need further study. IMPORTANCE We identified a novel picornavirus, boosepivirus, for the first time in China. Genetic evolutionary analysis revealed that NX20-1 strain was closely related to the Japanese strain Bo-12-38/2009/JPN and belonged to Boosepivirus B. In addition, we found that the virus was prevalent in China with an overall positivity rate of 10.6% (64 of 603 samples), and there was significant coinfection with other pathogens. Importantly, we found the prevalence of boosepivirus in sheep as well, suggesting that boosepivirus has a risk of spillover and can be transmitted across species.


Assuntos
Doenças dos Bovinos , Coinfecção , Humanos , Animais , Bovinos , Ovinos , Animais Domésticos , Reação em Cadeia da Polimerase , Doenças dos Bovinos/epidemiologia , Diarreia , Filogenia
11.
Front Vet Sci ; 10: 1100246, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36876018

RESUMO

Introduction: Mastitis is one of the most serious diseases affecting dairy farming, causing huge economic losses worldwide. Streptococcus agalactiae is the main pathogenic bacterium of contagious mastitis and can deliver a devastating blow to a farm's economy. Rapid detection is the key to disease control. Methods: In this study, a rapid detection method for S. agalactiae was established. This method combines filter paper extraction, multienzyme isothermal rapid amplification (MIRA), and lateral flow dipsticks (LFD). To simplify the extraction procedure, we designed a disposable extraction device (DED). First, DED performance was evaluated by polymerase chain reaction (PCR) and then the lysis formula and extraction time were optimized. Second, this study compared the extraction performance of a filter paper and an automatic nucleic acid extraction instrument. After screening primers, MIRA for S. agalactiae was established and combined with LFD. Specificity and sensitivity were evaluated after optimizing the reaction conditions. Results: The results showed that the lowest extraction line for DED was 0.01-0.001 ng/µl. In the specificity study, 12 different bacteria were tested, and only S. agalactiae was found to be positive. In the sensitivity study, seven dilution gradients were established, and the lowest detection line was 3.52 × 102 CFU/ml. Discussion: In summary, the method established in this study does not require laboratory equipment and is suitable for on-site detection. The entire method takes only 15 min, is low in cost, has high precision and low technical requirements for operators, which is in contrast with the high cost and cumbersome operation of traditional methods, and is suitable for on-site testing in areas with limited facilities.

12.
J Control Release ; 356: 402-415, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36858264

RESUMO

Aging is one of the critical factors to impair liver regeneration leading to a high incidence of severe complications after hepatic surgery in the elderly population without any effective treatment for clinical administration. As cell-free nanotherapeutics, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been demonstrated the therapeutic potentials on liver diseases. However, the effects of MSC-EVs on the proliferation of aged hepatocytes are largely unclear. In this study, we found MSCs could reduce the expression of senescence-associated markers in the liver and stimulate its regeneration in aged mice after receiving a two-thirds partial hepatectomy (PHx) through their secreted MSC-EVs. Using RNA-Seq and AAV9 vector, we mechanistically found that these effects of UC-MSC-EVs partially attributed to inducing Atg4B-related mitophagy. This effect repairs the mitochondrial status and functions of aged hepatocytes to promote their proliferation. And protein mass spectrum analysis uncovered that DEAD-Box Helicase 5 (DDX5) enriches in UC-MSC-EVs, which interacts with E2F1 to facilitate its nuclear translocation for activating the expression of Atg4B. Collectively, our data show that MSC-EVs act nanotherapeutic potentials in anti-senescence and promoting regeneration of aged liver by transferring DDX5 to regulate E2F1-Atg4B signaling pathway that induce mitophagy, which highlights the clinical application valuation of MSC-EVs for preventing severe complications in aged population receiving liver surgery.


Assuntos
Vesículas Extracelulares , Hepatopatias , Idoso , Humanos , Camundongos , Animais , Regeneração Hepática , Hepatócitos/metabolismo , Vesículas Extracelulares/metabolismo , RNA Helicases DEAD-box/metabolismo
13.
J Exp Clin Cancer Res ; 42(1): 63, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36922872

RESUMO

BACKGROUND: The Warburg effect is well-established to be essential for tumor progression and accounts for the poor clinical outcomes of hepatocellular carcinoma (HCC) patients. An increasing body of literature suggests that circular RNAs (circRNAs) are important regulators for HCC. However, few circRNAs involved in the Warburg effect of HCC have hitherto been investigated. Herein, we aimed to explore the contribution of circFOXK2 to glucose metabolism reprogramming in HCC. METHODS: In the present study, different primers were designed to identify 14 circRNAs originating from the FOXK2 gene, and their differential expression between HCC and adjacent liver tissues was screened. Ultimately, circFOXK2 (hsa_circ_0000817) was selected for further research. Next, the clinical significance of circFOXK2 was evaluated. We then assessed the pro-oncogenic activity of circFOXK2 and its impact on the Warburg effect in both HCC cell lines and animal xenografts. Finally, the molecular mechanisms of how circFOXK2 regulates the Warburg effect of HCC were explored. RESULTS: CircFOXK2 was aberrantly upregulated in HCC tissues and positively correlated with poor clinical outcomes in patients that underwent radical hepatectomy. Silencing of circFOXK2 significantly suppressed HCC progression both in vitro and in vivo. Mechanistically, circFOXK2 upregulated the expression of protein FOXK2-142aa to promote LDHA phosphorylation and led to mitochondrial fission by regulating the miR-484/Fis1 pathway, ultimately activating the Warburg effect in HCC. CONCLUSIONS: CircFOXK2 is a prognostic biomarker of HCC that promotes the Warburg effect by promoting the expression of proteins and miRNA sponges that lead to tumor progression. Overall, circFOXK2 has huge prospects as a potential therapeutic target for patients with HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , RNA Circular , Animais , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Prognóstico , RNA Circular/genética
14.
Virus Genes ; 59(3): 410-416, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36781819

RESUMO

Avian influenza virus (AIV) infection can lead to severe economic losses in the poultry industry and causes a serious risk for humans. A rapid and simple test for suspected viral infection cases is crucial. In this study, a reverse transcription recombinase-aided amplification assay (RT-RAA) for the rapid detection of all AIV subtypes was developed. The reaction temperature of the assays is at 39 °C and the detection process can be completed in less than 20 min. The specificity results of the assay showed that this method had no cross-reaction with other main respiratory viruses that affect birds, including Newcastle disease virus (NDV) and infectious bronchitis virus (IBV). The analytical sensitivity at a 95% confidence interval was 102 RNA copies per reaction. In comparison with a published assay for reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), the κ value of the RT-RAA assay in 384 avian clinical samples was 0.942 (p < 0.001). The sensitivity and specificity of the RT-RAA assay for avian clinical sample detection was determined as 97.59% (95% CI 93.55-99.23%) and 96.79% (95% CI 93.22-98.59%), respectively. The RT-RAA assay for AIV in this study provided an effective and practicable tool for AIV molecular detection.


Assuntos
Vírus da Influenza A , Influenza Aviária , Animais , Humanos , Transcrição Reversa , Influenza Aviária/diagnóstico , Recombinases/genética , Recombinases/metabolismo , Vírus da Influenza A/genética , Aves/genética , Sensibilidade e Especificidade
15.
Microorganisms ; 11(2)2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36838344

RESUMO

Lactococcus garvieae (L. garvieae) is a pathogenic gram-positive, catalase-negative (GPCN) bacterium that causes bovine mastitis. A total of 49 L. garvieae isolates were identified from 1441 clinical mastitis (CM) samples. The pathogenic effects of L. garvieae were studied with two infection models: bovine mammary epithelial cells cultured in vitro and murine mammary infections in vivo. The overall farm prevalence was 15.5% (13/84 farms in 9/19 provinces) and sample prevalence was 3.40% (49/1441). Post-treatment somatic cell count (SCC) post L. garvieae infection was significantly higher than the other GPCN pathogens isolated, and the bacteriological cure fraction was 41.94% (13/31) after intramammary antibiotic treatment. All L. garvieae isolates were resistant to rifaximin, 12.24% of isolates were resistant to cephalexin, and 10.20% (5/49) were multidrug-resistant (MDR). The most prevalent virulence genes were Hemolysin 1 (hly1)(100%), Hemolysin 2 (hly2) (97.96%), NADH oxidase (NADHO) (100%), Superoxide dismutase (SOD) (100%), Adhesin Pav (Pav) (100%), Adhesin PsaA (PsaA) (100%), Enolase (eno) (100%), Adhesin cluster 1(AC1) (100%), Adhesin cluster 2 (AC2) (100%), and several exopolysaccharides. L. garvieae rapidly adhered to bovine mammary epithelial cells, resulting in an elevated lactate dehydrogenase release. Edema and congestion were observed in challenged murine mammary glands and bacteria were consistently isolated at 12, 24, 48, 72, and 120 h after infection. We concluded that L. garvieae had good adaptive ability in the bovine and murine mammary cells and tissue. Given the resistance profile, penicillin and ampicillin are potential treatments for CM cases caused by L. garvieae.

16.
ACS Omega ; 8(7): 6361-6375, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36844508

RESUMO

To better understand the fracture propagation characteristics and spatial distribution pattern of a high-rank coal reservoir during hydraulic fracturing, a true triaxial physical simulation device was used to conduct a hydraulic fracturing experiment on large-sized raw coal from Zhijin, Guizhou Province, China. Computed tomography technology was used to scan the three-dimensional morphology of the fracture network before and after fracturing, then AVIZO software was used to reconstruct the internal fractures of the coal sample, and fractal theory was used to quantify the fractures. The results show that (1) the sudden increase of the pump pressure curve and acoustic emission signal is an important identification feature of hydraulic fractures, and the in situ stress difference coefficient plays a leading role in the complexity of coal and rock fractures. (2) When a hydraulic fracture encounters a primary fracture in the process of expansion, the opening of the primary fracture, the penetration, bifurcation, and turning of the hydraulic fracture are the main reasons for the formation of complex fractures, and the existence of a large number of primary fractures is the basis for the formation of complex fractures. (3) The fracture shape of coal hydraulic fracturing can be divided into three categories: complex fracture, plane fracture + cross fracture, and inverted T-shaped fracture. The fracture shape is closely related to the original fracture shape. The research results of this paper provide strong theoretical and technical support for coalbed methane mining design such as Zhijin high-rank coal reservoirs.

18.
Sci Total Environ ; 870: 161852, 2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-36709897

RESUMO

The coupling of multisource remote sensing data and the lack of measured runoff introduce input data and model parameters uncertainties to the remote sensing-driven distributed hydrological model (RS-DHM). The PB satellite remote sensing datasets of the Google Earth Engine (GEE) are widely used in RS-DHM and remote sensing runoff inversion research, but whether GEE can reduce the two abovementioned uncertainties is still unknown. To answer this question, twelve remote sensing data sources provided by GEE were used in this study to drive a typical RS-DHM called the remote sensing-driven distributed time-variant gain model (RS-DTVGM) and the remote sensing runoff inversion technology called remote sensing hydrological station (RSHS), and the contribution of GEE to the improving hydrological model uncertainties was quantitatively analyzed from 2001 to 2020. The results showed that (1) the GEE-based improved data preparation not only effectively reduced the uncertainty in the input data with better spatial-temporal continuity and a 6.20 % reduction in the total area occupied by invalid grids, but also enhanced the operational efficiency by reducing the image number, memory size and data processing time of the satellite remote sensing data by 83.63 %, 99.53 %, and 98.73 %, respectively; (2) the GEE-based RSHS technology provided sufficient data support for parameter adjustment and accuracy validation of the RS-DTVGM, which effectively reduced the uncertainty in the model parameters and increased the Nash efficiency coefficient (NSE) in the calibration and validation period from 0.67 to 0.87 and 0.75, respectively; and (3) the calibrated RS-DTVGM was more reliable and robust, and its runoff and evapotranspiration were consistent with the actual statistical data. In the future, GEE and RSHS technology should be widely adopted to drive the RS-DHM to more quickly and easily provide reliable hydrological processes simulation results for integrated water resource management, therefore achieving win-win results in terms of efficiency and accuracy.

19.
Microbes Infect ; 25(5): 105106, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36720402

RESUMO

Klebsiella pneumoniae (Kp) is now recognized as an urgent threat to public health since the emergence of multidrug-resistant and hypervirulent isolates. We identified a hypervirulent K2 isolate from the milk samples possibly associated with an infection incident in children, which raised the alarm to the zoonotic potential of bovine mastitis Kp as a foodborne pathogen. Subsequently, numerous K1, K2, K3, K5, K54 and K57 strains were identified from mastitis milk samples, and showed high pathogenicity in infected mouse. Further analysis based on complete genomes found that these isolates showed closely evolutionary relationships with the human hypervirulent strains in diverse phylogenetic lineages, suggesting their potential risk to public health.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Feminino , Bovinos , Criança , Humanos , Animais , Camundongos , Klebsiella pneumoniae/genética , Filogenia , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/veterinária , Virulência , Fatores de Virulência , Antibacterianos
20.
Educ Inf Technol (Dordr) ; 28(4): 3859-3892, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36210913

RESUMO

Many researchers investigated university students' behavioural intention to undertake online courses during COVID. However, few examined how students' intention might change throughout COVID by incorporating their learning capability and approaches. The universities in China went through a process from lockdown in February to reopening in September 2020. It provided a unique context for university students in China to experience emergent online learning for approximately six months before returning to normal face-to-face or blended learning on campus. The researchers conducted a questionnaire survey among 193 Chinese university students to investigate the changes in their behavioral intention to learn online throughout COVID. Additionally, the researchers explored the relationships between the participants' behavioral intention and the factors of learning capability in general, application of specific online learning strategies, online course engagement levels, and academic performance. It was found that the participants' intention to study online significantly increased during COVID and then slightly decreased after the university reopened. The participants' intention of online learning after COVID was predicted by their prior intention, learning capability, application of online learning strategies, and online course engagement. The participants' perceptions about online learning revealed that, when choosing future course delivery modes, they would a) reflect on their own disposition, capability, and needs, b) compare different learning modes, and c) examine course quality and teachers' competency. The participants also shared advice regarding their expectation of future online courses which may help shape university educators' pedagogical practices and provide insights for university online and blended course delivery from learners' perspectives. Supplementary Information: The online version contains supplementary material available at 10.1007/s10639-022-11320-0.

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