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1.
Microb Pathog ; : 106825, 2024 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-39074517

RESUMO

Short beak and dwarfism syndrome (SBDS) is attributed to Novel Goose Parvovirus (NGPV), which has inflicted significant economic losses on farming in China. Despite its significant impact, limited research has been conducted on the pathogenesis of this disease. The SD strain, a parvovirus variant isolated from ducks in Shandong province, was identified and characterized in our study. Phylogenetic analysis and sequence comparisons confirmed the classification of the SD strain as a member of NGPV. Based on this information, we established an animal model of SBDS by inoculating Cherry Valley ducks with the SD strain. Our findings indicate that infection with the SD strain leads to a reduction in body weight, beak length, width, and tibia length. Notably, significant histopathological alterations were observed in the thymus, spleen, and intestine of the infected ducks. Furthermore, the SD strain induces bone disorders and inflammatory responses. To evaluate the impact of NGPV on intestinal homeostasis, we performed 16S rDNA sequencing and gas chromatography to analyze the composition of intestinal flora and levels of short-chain fatty acids (SCFAs) in the cecal contents. Our findings revealed that SD strain infection induces dysbiosis in cecal microbial and a decrease in SCFAs production. Subsequent analysis revealed a significant correlation between bacterial genera and the clinical symptoms in NGPV SD infected ducks. Our research providing novel insights into clinical pathology of NGPV in ducks and providing a foundation for the research of NGPV treatment targeting gut microbiota.

2.
Vet Microbiol ; 296: 110187, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39053390

RESUMO

Short-beak and dwarf syndrome (SBDS) is caused by novel goose parvovirus (NGPV) infection, which leads to farm economic losses. Our research aimed to investigate the potential of administering isolated lactic acid bacteria (LAB) in alleviating SBDS in ducks. Eight wild LAB strains were isolated from duck feces and their biosecurity was investigated in both duck embryo fibroblast (DEF) and live ducks. Moreover, the LAB strains exhibited no detrimental effects on bone metabolism levels and facilitated the tight junction proteins (TJPs) mRNA expression, and contributing to the mitigation of inflammation in healthy ducks. Subsequently, we conducted in vitrol and in vivo experiments to assess the impact of LAB on NGPV infection. The LAB strains significantly reduced the viral load of NGPV and downregulated the mRNA levels of pro-inflammatory factors in DEF. Additionally, LAB treatment alleviated SBDS in NGPV-infected ducks. Furthermore, LAB treatment alleviated intestinal damage, and reduced the inflammatory response, while also mitigating bone resorption in NGPV-infected ducks. In conclusion, the LAB strains isolated from duck feces have favorable biosecurity and alleviate SBDS in ducks, and the mechanism related to LAB improves intestinal barrier integrity, alleviates inflammation, and reduces bone resorption. Our study presents a novel concept for the prevention and treatment of NGPV, thereby establishing a theoretical foundation for the future development of probiotics in the prevention and treatment of NGPV.

3.
Plants (Basel) ; 13(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38891251

RESUMO

Owing to the rising demand for vegetable soybean products, there is an increasing need for high-yield soybean varieties. However, the complex correlation patterns among quantitative traits with genetic architecture pose a challenge for improving vegetable soybean through breeding. Herein, a genome-wide association study (GWAS) was applied to 6 yield-related traits in 188 vegetable soybean accessions. Using a BLINK model, a total of 116 single nucleotide polymorphisms (SNPs) were identified for plant height, pod length, pod number, pod thickness, pod width, and fresh pod weight. Furthermore, a total of 220 genes were found in the 200 kb upstream and downstream regions of significant SNPs, including 11 genes encoding functional proteins. Among them, four candidate genes, Glyma.13G109100, Glyma.03G183200, Glyma.09G102200, and Glyma.09G102300 were analyzed for significant haplotype variations and to be in LD block, which encode MYB-related transcription factor, auxin-responsive protein, F-box protein, and CYP450, respectively. The relative expression of candidate genes in V030 and V071 vegetable soybean (for the plant height, pod number, and fresh pod weight of V030 were lower than those of the V071 strains) was significantly different, and these genes could be involved in plant growth and development via various pathways. Altogether, we identified four candidate genes for pod yield and plant height from vegetable soybean germplasm. This study provides insights into the genomic basis for improving soybean and crucial genomic resources that can facilitate genome-assisted high-yielding vegetable soybean breeding.

4.
Poult Sci ; 103(8): 103888, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38851180

RESUMO

Outbreaks of hepatitis-hydropericardium syndrome (HHS) caused by fowl adenovirus serotype 4 (FAdV-4) have resulted in huge economic losses to the poultry industry in China since 2015. However, commercially available vaccines against the FAdV-4 infection remain scarce. In our study, subunit vaccine candidates derived from the bacterially expressed recombinant Fiber1 knob domain and Fiber2 knob domain fusion protein (termed as Fiber1/2 knob subunit vaccine) and Fiber2 protein (termed as Fiber2 subunit vaccine) of the FAdV-4 SDSX strain were developed. Immunogenicity evaluation showed that the Fiber1/2 knob subunit vaccine induced the production of antibodies at 7 d postvaccination (dpv), earlier than the Fiber2 subunit vaccine. Moreover, the neutralizing antibody level of the Fiber1/2 subunit vaccine group was higher than the Fiber2 subunit vaccine group, showing significant differences at 14, 21, and 28 dpv. Immune protection test results revealed that both Fiber1/2 knob subunit and Fiber2 subunit vaccines could protect chickens from death against FAdV-4 challenge, although the weight of chickens in the Fiber1/2 knob subunit vaccine group decreased less. Furthermore, analysis of plasma Glutamic oxaloacetic transaminase (AST) and blood glutamic pyruvic transaminase (ALT) levels suggested that the Fiber1/2 subunit vaccine can significantly inhibit liver damage caused by FAdV-4 infection and is more effective in blocking the pathogenicity of FAdV-4 in target organs. In addition, the Fiber1/2 knob subunit vaccine further reduced the viral load in different tissues and virus shedding in chickens than the Fiber2 subunit vaccine. Overall, the Fiber1/2 knob subunit vaccine was more effective than the Fiber2 subunit vaccine. These findings lay the foundation for the development of more effective FAdV-4 subunit vaccines.


Assuntos
Infecções por Adenoviridae , Aviadenovirus , Galinhas , Doenças das Aves Domésticas , Vacinas de Subunidades Antigênicas , Animais , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/imunologia , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Infecções por Adenoviridae/veterinária , Infecções por Adenoviridae/prevenção & controle , Infecções por Adenoviridae/virologia , Infecções por Adenoviridae/imunologia , Aviadenovirus/imunologia , Vacinas Virais/imunologia , Sorogrupo
5.
Poult Sci ; 103(7): 103853, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38795515

RESUMO

Short-beak and dwarf syndrome (SBDS) is caused by infection with novel goose parvovirus (NGPV), which leads to intestinal dysbiosis, developmental delay, short beak, lameness, and paralysis in ducks and is the cause of skeletal health problems. NGPV infection can cause intestinal microbial disturbances, but it is still unclear whether the intestinal microbiota affects the pathogenicity of NGPV. Here, the effects of intestinal microbiota on NGPV-induced SBDS in Cherry Valley ducks were assessed by establishing a duck model for gut microflora depletion/reestablishment through antibiotics (ABX) treatment/fecal microbiota transplanted (FMT). By measuring body weight, beak length, beak width and tarsal length, we found that SBDS clinical symptoms were alleviated in ducks treated with ABX, but not in FMT ducks. Next, we conducted a comprehensive analysis of bone metabolism, gut barrier integrity, and inflammation levels using quantitative real-time PCR (qPCR), enzyme linked immunosorbent assay (ELISA), biochemical analysis and histological analysis. The results showed that ABX treatment improved bone quality reduced bone resorption, mitigated tissue lesions, protected intestinal barrier integrity, and inhibited systemic inflammation in NGPV-infected ducks. Moreover, cecal microflora composition and short-chain fatty acids (SCFAs) production were examined by bacterial 16S rRNA sequencing and gas chromatography. The results revealed that ABX treatment mitigated the decreased abundance of Firmicutes and Bacteroidota in NGPV-infected ducks, as well as increased SCFAs production. Furthermore, ABX treatment reduced the mucosa-associated lymphoid tissue lymphoma translocation protein 1 (Malt1) and nuclear factor κB (NF-κB) expression, which are correlated with systemic inflammation in SBDS ducks. These findings suggested that intestinal microflora depletion alleviated NGPV-induced SBDS by maintaining intestinal homeostasis, inhibiting inflammatory response and alleviating bone resorption. These results provide evidence for the pivotal role of intestinal microbiota in the process of SBDS and contribute a theoretical basis for the feasibility of microecological preparation as a method to control SBDS.


Assuntos
Patos , Microbioma Gastrointestinal , Infecções por Parvoviridae , Parvovirinae , Doenças das Aves Domésticas , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/microbiologia , Infecções por Parvoviridae/veterinária , Infecções por Parvoviridae/virologia , Parvovirinae/genética , Parvovirinae/fisiologia , Antibacterianos/farmacologia , Antibacterianos/administração & dosagem , Transplante de Microbiota Fecal/veterinária
6.
Mitochondrial DNA B Resour ; 9(5): 616-620, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38737393

RESUMO

Tylopilus brunneirubens is a common species in southern China. It is known for brown to dark brown pileus, white context turning reddish brown or rust brown when touched and distinct reticulation on the upper stem. However, little is known about its mitochondrial genome and its relationship with other boletes. Our analysis revealed that the mitochondrial genome of this species is a circular DNA molecule that spans 32,389 bp. It contains 15 core protein-coding genes, 24 transfer RNA genes, and two ribosomal RNA genes. The base composition of the mitochondrial genome is as follows: A (37.20%), C (11.32%), G (12.48%), and T (39.00%), with a GC content of 23.80%. Furthermore, a phylogenetic tree based on 24 mitochondrial genomes provided valuable insights into the phylogenetic relationships of Tylopilus brunneirubens with other boletes for the first time.

7.
Animals (Basel) ; 14(2)2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38254404

RESUMO

Porcine circovirus type 3 (PCV3) is endemic in swine worldwide and causes reproductive disorders, dermatitis and nephrotic syndrome, and multi-organ inflammation. Currently, there is a growing need for rapid and accurate diagnostic methods in disease monitoring. In this study, four monoclonal antibodies (mAbs) against PCV3 capsid proteins were prepared (mAbs 2F6, 2G8, 6E2, and 7E3). MAb 7E3, which had the highest binding affinity for the Cap protein, was chosen for further investigation. A novel B cell epitope 110DLDGAW115 was identified using mAb 7E3. An epitope-blocking (EB) enzyme-linked immunosorbent assay (ELISA) was successfully developed using horseradish-peroxidase-labeled mAb 7E3 to detect PCV3 antibodies in porcine sera. Moreover, the EB-ELISA showed no specific reaction with other porcine disease sera, and the cut-off value was defined as 35%. Compared with the commercial ELISA, the percentage agreement was 95.59%. Overall, we have developed a novel EB-ELISA method that accurately and conveniently detects PCV3 in serum, making it a valuable tool for the clinical detection of PCV3 infection.

8.
Mitochondrial DNA B Resour ; 9(1): 20-23, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38187009

RESUMO

Aureoboletus raphanaceus is a member of boletoid mushroom, which is named after its distinctive radish smell. The mitochondrial genome and phylogenetic relationships with other boletes need to be investigated to gain a comprehensive understanding of it. In this study, we sequenced the mitochondrial genome of A. raphanaceus using next-generation sequencing technology and found that its mitochondrial genome is a circular DNA molecule measuring 42,157 bp. It consists of 15 core protein-coding genes, 27 transfer RNA genes, and two ribosomal RNA genes. The mitochondrial genome had a base composition of A (39.89%), C (11.06%), G (11.67%), and T (37.38%), with a GC content of 22.73%. A phylogenetic tree based on 22 mitochondrial genomes was constructed, which provided the first insights into the phylogenetic relationships of this species with related boletes.

9.
Mitochondrial DNA B Resour ; 9(1): 46-49, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38197052

RESUMO

Butyriboletus hainanensis, a macrofungus belonging to the Boletaceae family, is named after its collection location on Hainan Island, China. However, little is known about its mitochondrial genome and its phylogenetic relationship with other boletes. In this study, we utilized next-generation sequencing technology to sequence the mitochondrial genome of Bu. hainanensis. Our findings revealed that the mitochondrial genome of this species is presumably a circular DNA molecule spanning 36,592 bp. It consists of 15 protein-coding genes, 27 transfer RNA genes, and two ribosomal RNA genes. The base composition of the mitochondrial genome is as follows: A (36.64%), C (12.22%), G (11.73%), and T (39.41%), with a GC content of 23.95%. Additionally, a phylogenetic tree was constructed based on 22 mitochondrial genomes, which provided valuable insights into the phylogenetic relationships of Bu. hainanensis with other boletes for the first time.

10.
Nat Prod Bioprospect ; 13(1): 46, 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37919477

RESUMO

Three previously undescribed compounds, cordycicadione (1), cordycicadin F (2), and 7-hydroxybassiatin (3), were isolated from the cultures of Cordyceps cicadae JXCH1, an entomopathogenic fungus. Their structures and relative configurations were elucidated primarily by NMR spectroscopic analysis. The absolute configurations of 1 and 2 were determined by ECD calculations. Single-crystal X-ray diffraction method was adopted to determine the absolute configuration of 3. Compound 2 is a polycyclic polyketide with an unusual enol ether moiety and a spiro ring. The compounds obtained in this study were subjected to screening their inhibition against the proliferation of the human lung cancer cell line A549 and the production of nitric oxide in murine macrophages RAW264.7.

11.
Mitochondrial DNA B Resour ; 8(10): 1067-1070, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37829256

RESUMO

Lanmaoa macrocarpa is a boletoid mushroom from the family Boletaceae and was named after its relatively larger basidiocarp and bluish color change when bruised. At present, its mitochondrial genome and phylogenetic relationships with other boletes remain unexplored. In this study, we sequenced the mitochondrial genome of L. macrocarpa using next-generation sequencing technology and found that its mitochondrial genome, a circular DNA molecule of 38,139 bp, comprised 15 core protein-coding genes, 26 transfer RNA genes and two ribosomal RNA genes. The mitochondrial genome had a base composition of A (37.05%), C (12.08%), G (11.42%) and T (39.45%) with a GC content of 23.50%. A phylogenetic tree based on 20 mitochondrial genomes was constructed, which revealed the phylogenetic relationships of this species with related boletes for the first time.

12.
Virus Res ; 336: 199194, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37579847

RESUMO

As a highly pathogenic large DNA virus, African swine fever virus (ASFV) has huge particles and numerous encoded proteins. At present, few of the existing studies on ASFV proteins have investigated the function of p17. Specific antibodies against p17 to promote the development of prevention techniques against African swine fever (ASF) are urgently needed. Herein, we successfully expressed ASFV p17 in CHO cells using a suspension culture system and generated a monoclonal antibody (mAb) against p17. The mAb recognized a novel linear epitope (8LLSHNLSTREGIK20) and exhibited specific reactivity, which was conducive to the identification of ectopically expressed p17, the recombinant porcine reproductive and respiratory syndrome virus expressing p17, and the ASFV-SY18. The epitope was conservative among genotype I and genotype II ASFV strains. Overall, the mAb against p17 revealed efficient detection and promising application prospects, making it a useful tool for future vaccine research on ASF. Determination of the conserved linear epitope of p17 would contribute to the in-depth exploration of the biological function of ASFV antigen protein.

13.
Food Chem X ; 18: 100707, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37397187

RESUMO

The olive vegetable is popular food owing to its unique flavor. This study innovatively used headspace-gas chromatography-ion mobility spectrometry to evaluate olive vegetables' volatiles under different conditions. A total of 57 volatile compounds were determined from olive vegetables, including 30 aldehydes, 8 ketones, 5 alcohols, 2 esters, 8 hydrocarbons, 1 furans, 3 sulfur compounds. The PCA distinguished the olive vegetable stored at different conditions by volatiles. The gallery plot showed that olive vegetables stored at 4 °C for 21 d produced more limonene, which had a desirable fruity odor. The (E)-2-octenal, (E)-2-pentenal, (E,E)-2,4-heptadienal, 5-methylfurfural, and heptanal in fresh olive vegetables were lowest and increased with storage time. Furthermore, the change of volatiles was the least when the olive vegetable was stored at 0 °C. This study can provide theoretical bases for improving the flavor quality of olive vegetables and developing traditional food for standardized industrial production.

14.
J Colloid Interface Sci ; 650(Pt B): 1591-1604, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37490836

RESUMO

We propose to enhance photothermal conversion via doping titanium carbide (Ti3C2) MXene nanosheets on the surfaces of phase-change microcapsules consisted of the n-Octadecane core and styrene divinylbenzene copolymer shell. Detected by scanning electron microscopy, the microcapsules showed a usually circular form with an appropriate dispersion. The thermal properties of the microcapsules were characterized using the differential scanning calorimetry and thermal conductivity instruments, realizing an excellent phase-change enthalpy of around 140 J/g, high encapsulation ratio of over 64 %, good heat transfer of 0.294 ± 0.003 W/(m·K), and great thermal reliability. More importantly, the microcapsules doped with Ti3C2 MXene nanosheets reach a solar-to-heat conversion efficiency of 85 ± 7 %, a substantial enhancement by 240 % in comparison with non-doping sample. The Ti3C2 MXene-doped microcapsules with excellent heat storage and solar-to-heat conversion capabilities offer great potential for high-efficiency solar energy utilization and can be applied to thermal energy storage systems and direct absorption solar collectors.

15.
Virus Res ; 334: 199181, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37495116

RESUMO

Porcine reproductive and respiratory syndrome virus (PRRSV) has seriously affected the viability of swine industries worldwide, and effective measures to control PRRSV are urgently required. Understanding the mechanisms of action of antiviral proteins is crucial for developing antiviral strategies. Interferon-induced bone marrow stromal cell antigen 2 (BST2) can inhibit the replication of various viruses via different pathways. However, little is known about the effects of BST2 on PRRSV. Therefore, this study aimed to evaluate whether the interferon-induced BST2 can inhibit PRRSV replication. We used western blotting and RT-qPCR techniques to analyze the effect of BST2 overexpression and knockdown on PRRSV replication. Overexpression of BST2 inhibited the replication of PRRSV, whereas knockdown of BST2 by small interfering RNA promoted PRRSV replication. Additionally, the expression of BST2 was upregulated during the early phase of PRRSV infection in porcine alveolar macrophages. Analysis of PRRSV proteins showed that BST2 restricted the expression of several non-structural viral proteins. BST2 downregulated the expression of Nsp12 through a proteasome-dependent pathway and downregulated the expression and transcription of E protein. These findings demonstrate the potential of BST2 as a critical regulator of PRRSV replication.


Assuntos
Síndrome Respiratória e Reprodutiva Suína , Vírus da Síndrome Respiratória e Reprodutiva Suína , Suínos , Animais , Vírus da Síndrome Respiratória e Reprodutiva Suína/metabolismo , Proteínas Virais , Replicação Viral , Antivirais/farmacologia , Interferons , Síndrome Respiratória e Reprodutiva Suína/genética , Macrófagos Alveolares , Proteínas não Estruturais Virais/metabolismo
16.
Asia Pac J Clin Nutr ; 32(2): 206-214, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37382318

RESUMO

BACKGROUND AND OBJECTIVES: Malnutrition is associated with pulmonary tuberculosis (PTB). The aim of this study is to investigate the association between persistent malnutrition and the effect of PTB treatment. METHODS AND STUDY DESIGN: A total of 915 PTB patients were included. Baseline demographic information, anthropometry, and nutritional indicators were measured. The treatment effect was assessed by combinations of clinical manifestations, sputum smear, chest computerized tomography, gastrointestinal symptoms, and the indexes of liver function. Persistent malnutrition was considered when one or more indicators of malnutrition were lower than the reference standards in two tests on admission and after one month of treatment. Clinical symptom score (TB score) was used to assess the clinical manifestations. The generalized estimating equation (GEE) was used to assess the associations. RESULTS: In GEE analyses, patients with underweight had a higher incidence of TB score >3 (OR=2.95; 95% CI, 2.28-3.82) and lung cavitation (OR=1.36; 95% CI, 1.05-1.76). Hypoproteinemia was associated with a higher risk of TB score >3 (OR=2.73; 95% CI, 2.08-3.59) and sputum positive (OR=2.69; 95% CI, 2.08-3.49). Anemia was associated with a higher risk of TB score >3 (OR=1.73; 95% CI, 1.33-2.26), lung cavitation (OR=1.39; 95% CI, 1.19-1.63), and sputum positive (OR=2.23; 95% CI, 1.72-2.88). Lymphocytopenia was associated with a higher risk of gastrointestinal adverse reactions (OR=1.47; 95% CI, 1.17-1.83). CONCLUSIONS: Persistent malnutrition within one month of treatment can adversely affect anti-tuberculosis treatment. Nutritional status during anti-tuberculosis treatment should be continuously monitored.


Assuntos
Desnutrição , Humanos , Estudos Transversais , Desnutrição/complicações , Desnutrição/epidemiologia , China/epidemiologia , Estado Nutricional , Antituberculosos/uso terapêutico
17.
Huan Jing Ke Xue ; 44(6): 3562-3572, 2023 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-37309971

RESUMO

In order to understand the pollution level and ecological risk of heavy metals in topsoil of Chuzhou City, a total of 4360 soil samples in Chuzhou City were collected, and the concentrations of eight heavy metals including Cr, Zn, Pb, Cu, Ni, Cd, As, and Hg were measured. Correlation analysis, cluster analysis, and principal component analysis were used to analyze the sources of the heavy metals, and the enrichment factor index, single-factor pollution index, pollution load index, geo-accumulation index method, and potential ecological risk index were selected to assess the environmental risk of the eight heavy metals in the topsoil. The results showed that the average values of Cr, Zn, Pb, Cu, Ni, Cd, As, and Hg contents in the surface soil of Chuzhou City were higher than the background value of that in the soil of Yangtze-Huaihe River Basin of Anhui, and Cd, Ni, As, and Hg were significantly different in space and influenced by external disturbance. The eight types of heavy metals could be divided into four categories based on correlation analysis, cluster analysis, and principal component analysis. Cr, Zn, Cu, and Ni were from natural background sources; As and Hg mainly came from sources of industrial and agricultural pollution; Pb mainly came from the sources of transportation pollution and industrial and agricultural pollution; and Cd came from the sources of transportation pollution, natural background, and industrial and agricultural pollution. The overall pollution degree of Chuzhou City was low, and the ecological risk level was at a slight level based on the pollution load index and the potential ecological risk index; however, the ecological risk of Cd and Hg was generally serious, and these two heavy metals should be taken as the objects of priority control. The results provided a scientific basis for soil safety utilization and classification control in Chuzhou City.

18.
Materials (Basel) ; 16(10)2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37241257

RESUMO

PH13-8Mo stainless steel has been widely used in aerospace, petroleum and marine construction, obtaining continuous investigation attention in recent years. Based on the response of a hierarchical martensite matrix and possible reversed austenite, a systematic investigation of the evolution of the toughening mechanisms in PH13-8Mo stainless steel as a function of aging temperature was carried out. It showed there was a desirable combination of high yield strength (~1.3 GPa) and V-notched impact toughness (~220 J) after aging between 540 and 550 °C. With the increase of aging temperature, the martensite matrix was recovered in terms of the refined sub-grains and higher ratio of high-angle grain boundaries (HAGBs). It should be noted there was a reversion of martensite to form austenite films subjected to aging above 540 °C; meanwhile, the NiAl precipitates maintained a well-coherent orientation with the matrix. Based on the post mortem analysis, there were three stages of the changing main toughening mechanisms: Stage I: low-temperature aging at around 510 °C, where the HAGBs contributed to the toughness by retarding the advance of cracks; Stage II: intermediate-temperature aging at around 540 °C, where the recovered laths embedded by soft austenite facilitated the improvement of toughness by synergistically increasing the advance path and blunting the crack tips; and Stage III: without the coarsening of NiAl precipitates around 560 °C, more inter-lath reversed austenite led to the optimum toughness, relying on "soft barrier" and transformation-induced plasticity (TRIP) effects.

19.
Front Vet Sci ; 10: 1128863, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36960147

RESUMO

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Classical Swine Fever Virus (CSFV) are two important pathogens, which cause serious impact on swine industry worldwide. In our previous research, rPRRSV-E2, the recombinant PRRSV expressing CSFV E2 protein, could provide sufficient protection against the lethal challenge of highly pathogenic PRRSV and CSFV, and could maintained genetically stable in vitro. Here, to evaluate the virulence reversion potential risk, rPRRSV-E2 had been continuously passaged in vivo, the stability of E2 expression and virulence of the passage viruses were analyzed. The results showed that no clinical symptoms or pathological changes could be found in the inoculated groups, and there were no significant differences of viraemia among the test groups. Sequencing and IFA analysis showed that the coding gene of exogenous CSFV E2 protein existed in the passaged viruses without any sequence mutations, deletions or insertions, and could expressed steadily. It could be concluded that the foreign CSFV E2 gene in the genome of rPRRSV-E2 could be maintained genetically stable in vivo, and rPRRSV-E2 strain had relatively low level of potential risk for virulence reversion.

20.
Vet Microbiol ; 279: 109678, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36758273

RESUMO

Pseudorabies virus (PRV) variants have been widely prevalent since 2011, leading to substantial losses to the swine industry. Although PRV can cause cross-species transmission and induce human infection, no drugs can currently prevent PRV infection. Interferons (IFNs) and interleukin-2 (IL-2) are important cytokines that mediate several biological functions including antiviral activity and immune regulation. In this study, we expressed and purified a recombinant porcine IFN-α and IL-2 fusion protein (rPoIFNα+IL-2), which did not show a cytotoxic effect on PK-15 cells. The antiviral activity was evaluated in PK-15 cells using the cytopathic effect inhibition method, and the results indicated that rPoIFNα+IL-2 can inhibit the replication of PRV, with an antiviral activity of approximately 104 U/mL. Moreover, the proliferation of peripheral blood mononuclear cells was enhanced by rPoIFNα+IL-2. Additionally, rPoIFNα+IL-2 substantially increased the expression of IFN-stimulated genes, including IFIT1, ISG15, MX1, and OAS, which are critical for antiviral activity. Furthermore, rPoIFNα+IL-2 alleviated the clinical symptoms and reduced mortality in mice infected with PRV. Simultaneously, rPoIFNα+IL-2 increased the expression levels of IFN-γ and IL-10 and inhibited the expression of IL-1ß and IL-6. Additionally, the viral DNA copies in different tissues in the rPoIFNα+IL-2-treated group were lower than those in the untreated group. These findings indicate that rPoIFNα+IL-2 may serve as an antiviral agent for the prevention and treatment of PRV infection and may expand the potential function of IFN antiviral drugs in the future.


Assuntos
Herpesvirus Suídeo 1 , Interleucina-2 , Suínos , Humanos , Animais , Camundongos , Interleucina-2/farmacologia , Herpesvirus Suídeo 1/genética , Leucócitos Mononucleares , Interferon-alfa/farmacologia , Antivirais/farmacologia
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