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1.
Genomics ; 112(2): 1444-1453, 2020 03.
Article in English | MEDLINE | ID: mdl-31454518

ABSTRACT

BACKGROUND: Brucellosis is a bacterial disease caused by Brucella infection. Brucella abortus strain A19 is a spontaneously attenuated vaccine strain that has been used in vaccination of cattle against brucellosis. Until now, the physiological and molecular mechanisms of A19 are still unknown. RESULTS: In this paper, the whole-genome sequence of B. abortus A19 was performed using Illumina Hiseq 4000 and PacBio sequencing technology and comparative genomics analysis were carried out with the whole genome sequences of B. abortus strains S19. This analysis indicated that the two vaccine strains have a high degree of similarity in genomic structure. We further analysis of the difference in genomic structure between A19 and S19. And found some differential genes such as eryC, eryD and eryF. Of the other different proteins between A19 and S19, such as outer membrane protein, 2-isopropylmalate synthase, citramalate synthase, GntR family transcriptional regulator and ABC transporters, no clear effects related to bacterial virulence were found, pending further investigation. CONCLUSION: The data presented here provide a reasonable basis for designing Brucella vaccines that can be used in other strains.


Subject(s)
Brucella Vaccine/genetics , Brucella abortus/genetics , Genes, Bacterial , Immunogenicity, Vaccine/genetics , ATP-Binding Cassette Transporters/genetics , Bacterial Outer Membrane Proteins/genetics , Brucella Vaccine/immunology , Brucella abortus/immunology , Cytochrome P-450 Enzyme System/genetics , Sequence Homology
2.
Virol J ; 12: 73, 2015 May 07.
Article in English | MEDLINE | ID: mdl-25948546

ABSTRACT

BACKGROUND: Bovine viral diarrhea virus (BVDV) infections are endemic in cattle populations worldwide and cause major economic losses. Thus, an effective vaccine is needed against the transmission of BVDV. The glycoprotein E(rns) is one of the envelope proteins of this virus and shows BVDV-related immunogenicity. Here, we report the use of Panax ginseng as an alternative production platform for the expression of glycoprotein E(rns) via Agrobacterium-mediated transformation. RESULT: Polymerase chain reaction (PCR) and reverse transcription (RT)-PCR analyses showed that pBI121-E(rns) was stably integrated into the chromosome of transformants. ELISA assay and Western blot analysis confirmed the antigenicity of plant-derived E(rns) glycoprotein. Immunogenicity was evaluated subcutaneously in deer using a soluble protein extract of dried transgenic ginseng hairy roots. Specific humoral and cell-mediated immune responses against BVDV were detected following immunization. CONCLUSION: These results demonstrated that the E(rns) glycoprotein could be expressed in ginseng hairy roots and that plant-derived glycoprotein E(rns) retained its antigenicity and immunogenicity.


Subject(s)
Diarrhea/veterinary , Disease Transmission, Infectious/prevention & control , Panax/metabolism , Pestivirus Infections/veterinary , Plants, Genetically Modified/metabolism , Viral Vaccines/immunology , Animals , Antibodies, Viral/blood , Deer , Diarrhea/prevention & control , Leukocytes, Mononuclear/immunology , Male , Panax/genetics , Pestivirus Infections/prevention & control , Plants, Genetically Modified/genetics , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/immunology , Vaccines, Synthetic/isolation & purification , Viral Vaccines/administration & dosage , Viral Vaccines/isolation & purification
3.
iScience ; 27(4): 109322, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38500828

ABSTRACT

Lunar-based equipment plays a vital role in the exploration of the moon because it undertakes the tasks of moving, transporting, digging, and so on. In order to control the gait of lunar-based equipment more precisely and guarantee mobile stability, the contact mechanism between its foot and lunar soil is worthy of in-depth study. In this paper, a contact model is proposed to predict the stress, strain, and displacement both on the contact surface and in the lunar soil when the foot is under vertical load. The axial stress in the proposed contact model is verified through the experiment and its accuracy in the lunar equipment is verified through simulation. The error is in a reasonable range and the influence depth of load conforms to the experiment results. This paper provides a relatively accurate model to describe the contact force between the lunar-based equipment's foot and the lunar soil and will promote the research of lunar exploration.

4.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Article in English | MEDLINE | ID: mdl-38065165

ABSTRACT

The paper presents a simple control and high-accuracy measurement method for a four-electrode conductivity probe based on the principle of the bi-directional voltage pulse. The two-way differential AC (alternating current) pulse voltage signal for the reference resistance and solution resistance is modulated into the single DC stationary voltage response signal to drop the demand for software and hardware and effectively eliminate the influence of excitation voltage pulse amplitude on measurement accuracy, and then the synchronous rectification DC measurement is proposed without any control timing. Meanwhile, the mathematical expression between the single output DC voltage signal and the solution conductivity is given. The test results in the laboratory and in the field indicate that the relative error of the conductivity measurement is within 2.5% in a conductance range of 10 uS/cm to 200 mS/cm, and the proposed measurement method has a good application prospect in application.

5.
Heliyon ; 9(10): e20808, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37860571

ABSTRACT

This study evaluated the anti-diabetic effect of polysaccharides isolated from Ornithogalum caudatum and their underlying mechanisms. To achieve this, a type 2 diabetes mellitus mouse model was established using a combination of a high-fat diet and low-dose streptozotocin injection. The mice were treated with Ornithogalumcaudatum polysaccharides (OCPs) for 4 weeks. OCPs treatment significantly decreased body weight loss, fasting blood glucose levels, and plasma insulin levels in diabetic mice. Additionally, compared with the untreated group, OCPs treatment significantly decreased total cholesterol, triacylglycerol, and low-density lipoprotein-cholesterol levels, but increased those of high-density lipoprotein-cholesterol in diabetic mice. Moreover, antioxidant enzyme activity and histopathology results revealed that OCPs effectively alleviated oxidative stress and streptozotocin-induced lesions by increasing antioxidant enzyme activity. Results from mechanistic studies showed that OCPs treatment significantly increased the expression of p-PI3K, p-Akt, and p-GSK-3ß in the liver. Moreover, OCPs optimized the gut microbiota composition of diabetic mice by significantly decreasing the Firmicutes/Bacteroidetes ratio and increasing the levels of beneficial bacteria (Muribaculaceae_norank, Prevotellaceae_UCG-001 and Alloprevotella). Overall, these findings suggest that OCPs exert anti-diabetic effects by triggering the PI3K/Akt/GSK-3ß signaling pathway and regulating the gut microbiota.

6.
Micromachines (Basel) ; 14(2)2023 Feb 19.
Article in English | MEDLINE | ID: mdl-36838188

ABSTRACT

Due to its unique structure, discoveries in nanoscale vacuum channel transistors (NVCTs) have demonstrated novel vacuum nanoelectronics. In this paper, the structural parameters of planar-type NVCTs were simulated, which illustrated the influence of emitter tip morphology on emission performance. Based on simulations, we successfully fabricated back-gate and side-gate NVCTs, respectively. Furthermore, the electric properties of NVCTs were investigated, showing the potential to realize the high integration of vacuum transistors.

7.
ACS Omega ; 8(26): 23889-23900, 2023 Jul 04.
Article in English | MEDLINE | ID: mdl-37426248

ABSTRACT

As a traditional medicine with extensive history, Ornithogalum caudatum has high nutritional and medicinal value. However, its quality evaluation criteria are insufficient because it is not included in the pharmacopeia. Simultaneously, it is a perennial plant, and the medicinal ingredients change with the growth years. Currently, studies on the synthesis and accumulation of metabolites and elements in O. caudatum during different growth years are unavailable. To address this issue, in this study, the 8 main active substances, metabolism profiles, and 12 trace elements of O. caudatum from different growth years (1, 3, and 5 years old) were analyzed. The main substances of O. caudatum changed significantly in different years of growth. Saponin and sterol contents increased with age; however, the polysaccharide content decreased. For metabolism profiling, ultrahigh-performance liquid chromatography tandem mass spectrometry was performed. Among the three groups, 156 differential metabolites with variable importance in projection values >1.0 and p < 0.05 were identified. Among the differential metabolites, 16 increased with increasing years of growth and have the potential to become age-identified markers. A trace element study showed that the contents of K, Ca, and Mg were higher, and the ratio of Zn/Cu was less than 0.1%. Heavy metal ions in O. caudatum did not increase with age. The results of this study provide a basis to evaluate the edible values of O. caudatum and facilitate further exploitation.

8.
Microorganisms ; 11(2)2023 Jan 29.
Article in English | MEDLINE | ID: mdl-36838298

ABSTRACT

According to the findings of a sheep breeding farm in Shaanxi, China, 2.53% (15/594) of sheep exhibited respiratory (clinical) symptoms such as dyspnoea, nasal discharge, wet cough, fever, and progressive emaciation. Although multi-drug treatment strategies (including ampicillin, tylosin, florfenicol, and ceftiofur) have been attempted to improve clinical outcomes, they have only been met with limited success, with a mortality rate of 40%. Ultimately, Aeromonas veronii (A. veronii) was identified as the causative pathogen for respiratory disease. The rates of symptomatic and asymptomatic sheep positive to A. veronii were 64.28% (95% CI 52.25-76.31%) and 8.02% (95% CI 6.96-9.08%), respectively. Pathogenicity tests demonstrated that the A. veronii is pathogenic to sheep and mice. The results of the antibiotic susceptibility tests revealed that the strain was sensitive to cefotaxime, gentamicin, and enrofloxacin and resistant to ampicillin, ceftiofur, amoxicillin, kanamycin, neomycin, streptomycin, tetracycline, florfenicol, and tylosin. We suggest that the combination of cefotaxime and gentamicin is an effective treatment based on the results of an antimicrobial susceptibility test, which exhibited good therapeutic efficacy. To the best of our knowledge, this is the first report in which pathogenic A. veronii has been documented as the cause of death in sheep in China. We concluded that pathogenic A. veronii poses a potential risk to the industry of sheep husbandry. This study's findings can help guide prevention and treatment plans for A. veronii infection in sheep.

9.
Animals (Basel) ; 13(17)2023 Aug 30.
Article in English | MEDLINE | ID: mdl-37685027

ABSTRACT

Hu sheep, a locally bred species in China known for its high productivity, is currently suffering from pneumonia. Here, we combine high-throughput 16SrRNA gene sequencing and bacterial culturing to examine the bacterial community in pneumonic Hu Sheep lungs (p < 0.05). The results showed that the abundance and diversity of lung bacteria in healthy sheep were significantly higher than those in pneumonia sheep (p = 0.139), while there was no significant difference between moderate and severe pneumonia. Furthermore, the composition of the lung microbiota community underwent significant alterations between different levels of pneumonia severity. The application of LEfSe analysis revealed a notable enrichment of Mannheimiae within the lungs of sheep afflicted with moderate pneumonia (p < 0.01), surpassing the levels observed in their healthy counterparts. Additionally, Fusobacterium emerged as the prevailing bacterial group within the lungs of sheep suffering from severe pneumonia. Integrating the results of bacterial isolation and identification, we conclusively determined that Mannheimia haemolytica was the primary pathogenic bacterium within the lungs of sheep afflicted with moderate pneumonia. Furthermore, the exacerbation of pneumonia may be attributed to the synergistic interplay between Fusobacterium spp. and other bacterial species. Our results provide new insights for guiding preventive and therapeutic measures for pneumonia of different severities in sheep.

10.
Microbiol Spectr ; 11(3): e0402422, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37036344

ABSTRACT

When it comes to the prevention of clinical signs and mortality associated with infection of the Newcastle disease virus (NDV), vaccination has been very effective. However, recent evidence has proven that more highly virulent strains are emerging that bypass existing immune protection and pose a serious threat to the global poultry industry. Here, a novel rescued adenovirus 5-coexpressed chicken granulocyte monocyte colony-stimulating factor (ChGM-CSF) bio-adjuvant and C22-hemagglutinin-neuraminidase (HN) boosted chickens' immunological genetic resistance and thus improved the immunological effectiveness of the critical new-generation vaccine in vitro and in vivo. Accordingly, the hemagglutination inhibition (HI) titers (log2) of the recombinant adenovirus (rAdv)-ChGM-CSF-HN-immunized chickens had greater, more persistent, and longer-lasting NDV-specific antibodies than the La Sota and rAdv-HN-inoculated birds. Moreover, humoral and adaptive immunological conditions were shown to be in harmony after rAdv-ChGM-CSF-HN inoculation and uniformly enhanced the expression of alpha interferon (IFN-α), IFN-ß, IFN-γ, interleukin-1ß (IL-1ß), IL-2, IL-16, IL-18, and IL-22. Postchallenge, the control challenge (CC), wild-type adenovirus (wtAdv), and rAdv-ChGM-CSF groups developed unique NDV clinical manifestations, significant viral shedding, high tissue viral loads, gross and microscopic lesions, and 100% mortality within 7 days. The La Sota, rAdv-HN, and rAdv-ChGM-CSF-HN groups were healthy and had 100% survival rates. The rAdv-ChGM-CSF-HN group swiftly regulated and stopped viral shedding and had lower tissue viral loads than all groups at 5 days postchallenge (dpc). Thus, the antiviral activity of ChGM-CSF offered robust immune protection in the face of challenge and reduced viral replication convincingly. Our advance innovation concepts, combining ChGM-CSF with a field-circulating strain epitope, could lead to the development of a safe, genotype-matched, universal transgenic vaccine that could eradicate the disease globally, reducing poverty and food insecurity. IMPORTANCE We studied the biological characterization of the developed functional synthetic recombinant adenoviruses, which showed a high degree of safety, thermostability, and genetic stability for up to 20 passages. It was demonstrated through both in vitro and in vivo testing that the immunogenicity of the proposed vaccine, which uses the T2A peptide from the Thosea asigna virus capsid protein supported by glycine and serine, helps with efficiency to generate a multicistronic vector, enables expression of two functional proteins in rAdv-ChGM-CSF-HN, and is superior to that of comparable vaccines. Additionally, adenovirus can be used to produce vaccines matching the virulent field-circulating strain epitope. Because there is no preexisting human adenoviral immunity detected in animals, the potency of adenoviral vaccines looks promising. Also, it ensures that the living vector does not carry the resistance gene that codes for the kanamycin antibiotic. Accordingly, a human recombinant adenoviral vaccine that has undergone biological improvements is beneficial and important.


Subject(s)
Adenoviridae Infections , Newcastle Disease , Poultry Diseases , Viral Vaccines , Humans , Animals , Newcastle disease virus/genetics , Chickens , Neuraminidase , Hemagglutinins , Newcastle Disease/prevention & control , Adenoviridae , Antiviral Agents , Monocytes , Viral Vaccines/genetics , Vaccines, Synthetic , Genotype , Antibodies, Viral , Colony-Stimulating Factors/genetics , Granulocytes
11.
Gene ; 830: 146521, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35447245

ABSTRACT

BACKGROUND: Brucellosis is a widespread disease that affects animals and humans. The live attenuated Brucella abortus A19 strain is used for vaccination against brucellosis in China. In addition, the main mechanisms supporting the residual toxicity of A19 have not been elucidated. Here, we performed a comprehensive comparative analysis of the genome-wide sequence of A19 against the whole genome sequences of the published virulent reference strain 9-941. The primary objective of this study was to identify candidate virulence genes by systematically comparing the genomic sequences between the two genomes. RESULTS: This analysis revealed two deletion regions in the A19 genome, in which all included large fragments of 63 bp, and one of their gene function is related to ABC transporter permease protein. In addition, we have identified minor mutations in important virulence-related genes that can be used to determine the underlying mechanisms of virulence attenuation. The function of its virulence gene covers LysR family transcriptional regulator, outer membrane, MFS transporter and oxidoreductase etc. At the same time, a PCR differential diagnosis method was constructed, which can distinguish A19, S19 and most other commonly used Brucella viruent strains and vaccine strains. CONCLUSION: The data may help to provide resources for further detailed analysis of mechanisms for other Brucella vaccines. It laid the foundation for further distinguishing between vaccine immunity and virulent strains infection.


Subject(s)
Brucella Vaccine , Brucellosis , ATP-Binding Cassette Transporters , Animals , Brucella Vaccine/genetics , Brucella abortus/genetics , Brucellosis/prevention & control , Vaccination , Virulence/genetics
12.
Appl Spectrosc ; 76(9): 1068-1079, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35583031

ABSTRACT

In order to extract useful information from X-ray fluorescence (XRF) spectra and establish a high-accuracy prediction model of soil heavy metal contents, a hybrid model combining a deep belief network (DBN) with a tree-based model was proposed. The DBN was first introduced into feature extraction of XRF spectral data, which can obtain deep layer features of spectra. Owing to the strong regression ability of the tree-based model, it can offset the deficiency of DBN in prediction ability so it was used for predicting heavy metal contents based on the extracted features. In order to further improve the performance of the model, the parameters of model can be optimized according to the prediction error, which was completed by sparrow search algorithm and the gird search. The hybrid model was applied to predict the contents of As and Pb based on spectral data of overlapping peaks. It can be obtained that R2 of As and Pb reached 0.9884 and 0.9358, the mean square error of As and Pb are as low as 0.0011 and 0.0058, which outperform other commonly used models. That proved the combination of DBN and tree-based model can obtain more accurate prediction results.


Subject(s)
Metals, Heavy , Soil , Algorithms , Lead
13.
Micromachines (Basel) ; 13(8)2022 Aug 08.
Article in English | MEDLINE | ID: mdl-36014196

ABSTRACT

Recent discoveries in the field of nanoscale vacuum channel (NVC) structures have led to potential on-chip electron sources. However, limited research has reported on the structure or material parameters, and the superiority of a nanoscale vacuum channel in an electron source has not been adequately demonstrated. In this paper, we perform the structural optimization design of an NVC-based electron source. First, the structure parameters of a vertical NVC-based electron source are investigated. Moreover, the symmetrical NVC structure is further demonstrated to improve the emission current and effective electron efficiency. Finally, a symmetrical nano-vacuum channel structure is successfully fabricated based on simulations. The results show that the anode current exceeds 15 nA and that the effective electron efficiency exceeds 20%. Further miniaturizing the NVC structures in high integration can be utilized as an on-chip electron source, thereby, illustrating the potential in applications of electron microscopes, miniature X-ray sources and on-chip traveling wave tubes.

14.
Transbound Emerg Dis ; 69(6): 3606-3617, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36222239

ABSTRACT

The worldwide spread of pathogenic Escherichia coli, together with the multidrug resistant linked with extended-spectrum ß-lactamases (blaCTX-M , blaTEM and blaOXA ), not only affect the health of animals and humans but also bring huge economic losses to animal husbandry. Despite the high levels of virulence present in many extended-spectrum beta-lactamases (ESBLs)-producing E. coli isolates, however, few studies have comprehensively assessed the pathogenicity of ESBLs-producing E. coli isolates. Thus, the aim of the present study was to investigate the presence of virulence genes in third-generation cephalosporin-resistant E. coli and to assess their pathogenicity and zoonotic potential. Previously, we identified 67 ESBLs-producing E. coli strains from sheep anal swabs in northwest China. In this study, we genotypically and phenotypically characterized isolates of E. coli that produce ESBLs. According to the VirulenceFinder and virulence factors database, all ESBLs-producing E. coli strains harboured a wide range of virulence genes. The ColV plasmid-related genes (hlyF, ompT, iss, iutA and cvaC) were present in 52 (77.6%) ESBLs-producing E. coli isolates. Surprisingly, quite a number of extraintestinal pathogenic E. coli virulence-related genes were detected in 62 (92.5%) of 67 isolates. A total of 33 serotypes and 37 sequence types (STs) were found in 67 ESBLs-producing isolates. ST10 is the most prevalent ST, which is represented by five strains. The cluster analysis showed that CC10 and CC23 were the common clonal complexes (CCs). Predominant serotypes were O8 (10%) and O9 (9%) followed by 6% each of O89, O101 and O185. Most sheep-origin ESBLs-producing E. coli held the highly pathogenic to human and displayed moderate-to-vigorous-intensity motor capacity. The ESBLs-producing E. coli isolates with numerous virulence-related genes were able to cause multiple infectious diseases in animal models (mice, neonatal rats and Galleria mellonella). To our knowledge, this study represents an important first step for a comprehensive characterization of pathogenicity and zoonotic potential of sheep-origin ESBLs-producing E. coli isolates. These findings may be of significant value for the identification of pathogenicity and zoonotic potential risks associated with sheep-origin ESBLs-producing E. coli.


Subject(s)
Escherichia coli Infections , Extraintestinal Pathogenic Escherichia coli , Rodent Diseases , Sheep Diseases , Mice , Animals , Humans , Rats , Sheep , Escherichia coli/genetics , Virulence/genetics , Escherichia coli Infections/veterinary , beta-Lactamases/genetics , Extraintestinal Pathogenic Escherichia coli/genetics , Anti-Bacterial Agents
15.
Microbiol Spectr ; 10(4): e0159522, 2022 08 31.
Article in English | MEDLINE | ID: mdl-35943154

ABSTRACT

Development of extended-spectrum-ß-lactamase (ESBL)-producing Escherichia coli is one the greatest threats faced by mankind. Among animals, chickens, pigs, and cattle are reservoirs of these pathogens worldwide. Nevertheless, there is a knowledge gap on ESBL-producing E. coli from small ruminants (i.e., sheep and goats) in China. The aim of this study was to identify and characterize the resistance profiles, resistomes, and sequence features of 67 ESBL-producing E. coli isolates from sheep in northwest China. The findings showed that blaCTX-M and blaTEM were the most prevalent. Interestingly, we found that the resistance gene mcr-1 was widespread in sheep merely from Shaanxi areas, accounting for 19.2% (5/26). The highly prevalent serotypes and FumC-FimH (CH) typing isolates were O8 and C4H32, respectively. High-risk E. coli clones, such as sequence type 10 (ST10), ST23, ST44, and ST58, were also found in China's sheep population. A total of 67 ESBL-producing isolates were divided into five phylogenetic groups, namely, B1 (n = 47, 70.1%), B2 (n = 1, 1.5%), C (n = 14, 20.9%), E (n = 1, 1.5%), and F (n = 1, 1.5%), with the phylogenetic groups for 3 isolates (4.5%) remaining unknown. Moreover, ESBL-producing E. coli isolates were also characterized by the abundance and diversity of biocide/metal resistance genes and insert sequences. We found that in ESBL-producing E. coli isolates, there were two different types of isolates, those containing ESBL genes or not, which led to large discrepancies between resistance phenotypes and resistomes. In summary, our study provides a comprehensive overview of resistance profiles and genome sequence features in ESBL-producing E. coli and highlights the possible role of sheep as antibiotic resistance gene disseminators into humans. IMPORTANCE Antimicrobial resistance (AMR), especially the simultaneous resistance to several antibiotics (multidrug resistance [MDR]), is one of the greatest threats to global public health in the 21st century. Among animals, chickens, pigs, and cattle are reservoirs of these pathogens worldwide. Nevertheless, there is a knowledge gap on ESBL-producing E. coli from small ruminants in China. This study is the largest and most comprehensive analysis of ESBL-producing E. coli isolates from sheep, including antibiotic resistance profiles, phylogenetic groups, serotypes, multilocus sequence types (MLST), insert sequences (IS), antibiotic resistance genes, disinfectant resistance genes, and heavy metal resistance genes. We recommend extending the surveillance of AMR of sheep-origin E. coli to prevent future public health risks.


Subject(s)
Escherichia coli Infections , Escherichia coli Proteins , Animals , Anti-Bacterial Agents/pharmacology , Cattle , Chickens , Diarrhea , Escherichia coli , Escherichia coli Infections/epidemiology , Escherichia coli Infections/veterinary , Escherichia coli Proteins/genetics , Goats/genetics , Humans , Multilocus Sequence Typing , Phylogeny , Sheep/genetics , Swine , beta-Lactamases/genetics
16.
Nanomaterials (Basel) ; 11(4)2021 Apr 09.
Article in English | MEDLINE | ID: mdl-33918667

ABSTRACT

Here, we report on the high-performance blue quantum dots (QDs) light-emitting diodes (QLEDs), in which the ZnO nanoparticles (NPs) are employed as the electron transport layer (ETL) and optimized with different alcohol solvents. The experimental results demonstrate that the properties of solvent used for ZnO NPs-such as polarity, viscosity and boiling point-play a crucial role in the quality of film where they modulate the electron injection across the QDs/ETL interface. The maximum current efficiency of 3.02 cd/A and external quantum efficiency (EQE) of 3.3% are achieved for blue QLEDs with ZnO NPs dispersed in butanol, exhibiting obvious enhancement compared with the other solvents. This work provides a new method to select proper solvent for ETL which can further improve the device performance.

17.
Vet Microbiol ; 253: 108977, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33421684

ABSTRACT

A lentogenic strain of Newcastle disease virus (NDV) with an intracerebral pathogenicity index (ICPI) of 0.36 was derived by the passage of a mesogenic NDV isolate with an original ICPI of 1.04. Animal experiments showed that the original strain caused much severer clinical signs and mortality than the derived strain in chickens. To elucidate the molecular reason for this virulence change, the complete viral genomes of the original and derived strains were sequenced. Molecular analysis showed that both viruses contained the same fusion (F) protein with a cleavage site (Fcs) motif that is usually associated with velogenic viruses. Molecular comparison revealed five amino acid (aa) differences in nucleoprotein (NP) (aa 426), hemagglutinin-neuraminidase (HN) (aas 215 and 430), and large protein (L) (aas 1694 and 1767), accompanied by the changes of relevant biological activities in membrane fusion and replication. Thus, we believe that the virulence changes may induced by these mutations. Our findings make a foundation for more in-depth investigations of the molecular mechanism underlying virulence.


Subject(s)
Genome, Viral , Mutation , Newcastle Disease/virology , Newcastle disease virus/genetics , Newcastle disease virus/pathogenicity , Animals , Cell Line , Chick Embryo/virology , Chickens/virology , Cricetinae , Poultry Diseases/virology , Specific Pathogen-Free Organisms , Virulence , Virus Replication
18.
Front Microbiol ; 12: 699927, 2021.
Article in English | MEDLINE | ID: mdl-34394043

ABSTRACT

Pathogenic E. coli are among the most frequently isolated bacterial pathogens on large-scale sheep farms in China. Antibiotic use in wool sheep production is a risk factor for promoting the emergence of resistant E. coli. To reveal the differences of E. coli populations in sheep from different farming systems the antimicrobial resistance, virulence genes, biofilm formation, and phylogroups of 500 E. coli isolates obtained between September 2019 and December 2020 in northwest China from diarrheic infections of intensive farming and free-range sheep were analyzed. The antimicrobial susceptibility test for 12 classes of antimicrobial agents was determined using the broth microdilution susceptibility method, and PCR was used to detect the differences in virulence genes and phylogroups. Additionally, biofilm formation was determined using microtiter plate and slide agglutination methods. Among the 500 E. coli isolates, the majority of the isolates were multidrug resistant (75.4%) and carried at least one virulence gene (94.8%). We observed that 412 (82.4%), 360 (72.0%), and 266 (53.2%) are found to be resistant to sulfisoxazole, florfenicol, and tetracyclines, respectively. Resistance was also observed to mequindox (46.8%), ampicillin (43.6%), spectinomycin (38.6%), enrofloxacin (34.2%), ceftiofur (21.0%), gentamycin (20.4%), ceftazidime (17.8%), and polymyxin B (7.8%) but no resistance was found to meropenem. These results showed that strains from free-range subjects had fewer antibiotic resistance strains rather than sheep that were intensively farmed (P < 0.05). We observed fifteen virulence genes, of which etrA (n = 401, 80.2%) is the most common. In addition, EAEC (86.4%) is dominant among free-range sheep and EHEC (80.1%) is dominant among intensive farming. Among all virulence genes, the strongest correlation was found between etrA and papC gene (P < 0.001, OR = 455.68). Similarly, the strongest correlation was also found between eltA and sulfisoxazole (P < 0.001, OR = 877). Furthermore, the majority of the E. coli isolates belonged to phylogroup B1 (50.6%), followed by phylogroup C (20.6%), A (7.4%), E (7.4%), D (5.8%), B2 (1.6%), and F (1%). Interestingly, phylogroup B2 and D were all distributed in intensive farms. In addition, 33 (6.6%), 373 (74.6%), and 94 (18.8%) showed moderate, weak, and no connection biofilm formation ability, respectively. These data uncovered that wool sheep serve as a reservoir of pathogenic E. coli harboring multiple resistance phenotypes and virulence genes. The overlapping virulence-associated traits between IPEC and ExPEC indicated the zoonotic potential and safety threats of sheep food products. It is urgent to improve the proper use of antimicrobials in China as well as other countries.

19.
Sheng Wu Gong Cheng Xue Bao ; 36(2): 250-258, 2020 Feb 25.
Article in Zh | MEDLINE | ID: mdl-32147997

ABSTRACT

The objective of this study was to explore the link between long non-coding RNAs (lncRNAs) and resistance mechanism of albendazole in Haemonchus contortus by analyzing the gene expression profile of lncRNA in sensitive and resistant strains. This study provided the base for the resistance mechanism of Haemonchus contortus. In this experiment, the cDNA sequencing libraries were collected constructed for the sensitive and resistant strains of Haemonchus contortus, and the sequencing was performed using Illumina HiSeq 4000 platform, and differentially expressed lncRNAs (DEIncRNAs) were screened. Then the cis-targeted and trans-targeted genes of DElncRNAs were predicted, and the GO enrichment, KEGG pathway enrichment analysis were also made. The results displayed that 6 377 and 6 356 candidate lncRNA transcripts of sensitive and resistive strains were respectively obtained, 168 DElncRNAs of which were selected. Compared with resistive strains, there were 92 up-regulated and 76 down-regulated lncRNAs in sensitive strains. Meanwhile, 416 candidate target genes of DElncRNAs were obtained. The analytical results indicated that these genes participated in 641 GO terms and 92 pathways. The pathways involved in drug resistance are drug metabolism-other enzymes, drug metabolism-cytochrome P450, metabolism of xenobiotics by cytochrome P450 and so on. In conclusion, these findings inferred that some lncRNA-mediated target genes were associated with the resistance of Haemonchus contortus, and lncRNA may play an important role in the resistance of Haemonchus contortus. This study explored the expression profile of lncRNA in the Haemonchus contortus of sensitive and resistant strains. It was found that DElncRNAs in the sensitive and resistant strains, which helped to find out the Haemonchus contortus resistance mechanism of albendazole and provided a scientific basis for exploring the mechanism of resistance to Haemonchus contortus.


Subject(s)
Haemonchiasis , Haemonchus , Albendazole , Animals , RNA, Long Noncoding , Transcriptome
20.
Clin Exp Pharmacol Physiol ; 36(7): 734-8, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19215235

ABSTRACT

1. The purpose of the present study was to examine lung water transport properties and the expression and regulation of the alveolar endothelial water channel aquaporin (AQP)-1 and the epithelial water channel AQP-5 in aged mouse lung using gene expression analysis and water permeability measurements. 2. In aged (20-24-month-old) mice, AQP-1 and AQP-5 mRNA expression decreased by 55.5 and 50.3%, respectively, compared with that in young (8-10-week-old) mice (P < 0.01). In addition, AQP-1 and AQP-5 protein expression decreased in aged mice by 36.9 and 44.6%, respectively, compared with that in young mice (P < 0.01). 3. The osmotically driven water transport rate between the airspace and capillary compartments was reduced by 31.7% in aged mice compared with young mice (2.8 +/- 0.3 vs 4.1 +/- 0.3 mg/s, respectively; P < 0.01). The hydrostatically driven lung water accumulation rate in response to a 10 cmH(2)O increase in pulmonary artery pressure was also reduced in aged mice by 21.9% compared with young mice (0.32 +/- 0.06 vs 0.41 +/- 0.04 mg/s, respectively; P < 0.01). 4. There was a 62.7% decrease in serum glucocorticoids in aged mice compared with young mice (67.6 +/- 26.8 vs 181.3 +/- 44.4 nmol/L, respectively; P < 0.01). In vivo administration of dexamethasone (4 mg/kg) for 5 consecutive days to aged mice increased lung AQP-1 mRNA and protein expression by 2.1 +/- 0.1 fold (P < 0.01) and 1.8 +/- 0.2 fold (P < 0.01), respectively. Accordingly, osmotically and hydrostatically driven water transport rates increased by 35.6% (P < 0.01) and 31.2% (P < 0.01), respectively. 5. The present study provides the first evidence of altered lung water transport associated with downregulation of AQPs in aged lung. Blood glucocorticoid hormone levels are important to maintain normal AQP-1 expression in the lung microvascular endothelium. Corticosteroid-induced AQP-1 upregulation may contribute to the role of corticosteroids in accelerating oedema clearance in aged lung.


Subject(s)
Aging/metabolism , Aquaporin 1/metabolism , Aquaporin 5/metabolism , Down-Regulation/physiology , Extravascular Lung Water/metabolism , Aging/pathology , Animals , Biological Transport/physiology , Mice , Pulmonary Alveoli/metabolism , Pulmonary Edema/metabolism , Pulmonary Edema/pathology
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