Recombination of Porcine Reproductive and Respiratory Syndrome Virus: Features, Possible Mechanisms, and Future Directions.

Recombination is a pervasive phenomenon in RNA viruses and an important strategy for accelerating the evolution of RNA virus populations. Recombination in the porcine reproductive and respiratory syndrome virus (PRRSV) was first reported in 1999, and many case reports have been published in recent years. In this review, all the existing reports on PRRSV recombination events were collected, and the genotypes, parental strains, and locations of the recombination breakpoints have been summarized and analyzed. The results showed that the recombination pattern constantly changes; whether inter- or intra-lineage recombination, the recombination hotspots vary in different recombination patterns. The virulence of recombinant PRRSVs was higher than that of the parental strains, and the emergence of virulence reversion was caused by recombination after using MLV vaccines. This could be attributed to the enhanced adaptability of recombinant PRRSV for entry and replication, facilitating their rapid propagation. The aim of this paper was to identify common features of recombinant PRRSV strains, reduce the recombination risk, and provide a foundation for future research into the mechanism of PRRSV recombination.

A cyclical switch of gametogenic pathways in hybrids depends on the ploidy level.

The cellular and molecular mechanisms governing sexual reproduction are conserved across eukaryotes. Nevertheless, hybridization can disrupt these mechanisms, leading to asexual reproduction, often accompanied by polyploidy. In this study, we investigate how ploidy level and ratio of parental genomes in hybrids affect their reproductive mode. We analyze the gametogenesis of sexual species and their diploid and triploid hybrids from the freshwater fish family Cobitidae, using newly developed cytogenetic markers. We find that diploid hybrid females possess oogonia and oocytes with original (diploid) and duplicated (tetraploid) ploidy. Diploid oocytes cannot progress beyond pachytene due to aberrant pairing. However, tetraploid oocytes, which emerge after premeiotic genome endoreplication, exhibit normal pairing and result in diploid gametes. Triploid hybrid females possess diploid, triploid, and haploid oogonia and oocytes. Triploid and haploid oocytes cannot progress beyond pachytene checkpoint due to aberrant chromosome pairing, while diploid oocytes have normal pairing in meiosis, resulting in haploid gametes. Diploid oocytes emerge after premeiotic elimination of a single-copied genome. Triploid hybrid males are sterile due to aberrant pairing and the failure of chromosomal segregation during meiotic divisions. Thus, changes in ploidy and genome dosage may lead to cyclical alteration of gametogenic pathways in hybrids.

Non-target screening and prioritization of organic contaminants in seawater desalination and their ecological risk assessment.

The impact of desalination brine on the marine environment is a global concern. Regarding this, salinity is generally accepted as the major environmental factor in desalination concentrate. However, recent studies have shown that the influence of organic contaminants in brine cannot be ignored. Therefore, a non-targeted screening method based on comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS) was developed for identifying organic contaminants in the desalination brine. A total of 404 compounds were tentatively identified from four seawater desalination plants (three reverse osmosis plants and one multiple effect distillation plant) in China. The identified compounds were prioritized based on their persistence, bioaccumulation, ecotoxicity, usage, and detection frequency. Twenty-one (21) compounds (seven phthalates, ten pesticides, four trihalomethanes) were then selected for further quantitative analysis and ecological risk assessment, including compounds from the priority list along with substances from the same chemical classes. Ecologically risky substances in brine include diisobutylphthalate and bis(2-Ethylhexyl) phthalate, atrazine and acetochlor, and bromoform. Most of the contaminants come from raw seawater, and no high risk contaminants introduced by the desalination process have been found except for disinfection by-products. In brine discharge management, people believed that all pollution in raw seawater was concentrated by desalination process. This study shows that not all pollutants are concentrated during the desalination process. In this study, the total concentration of pesticide in the brine increased by 58.42%. The concentration of ∑PAEs decreased by 13.65% in reverse osmosis desalination plants and increased by 10.96% in the multi-effect distillation plant. The concentration of trihalomethane increased significantly in the desalination concentrate. The change in the concentration of pollutants in the desalination concentrate was related to the pretreatment method and the chemical characteristics of the contaminants. The method and results given in this study hinted a new idea to identify and control the environmental impact factors of brine.

Effector enrichment by Candidatus Liberibacter promotes Diaphorina citri feeding via Jasmonic acid pathway suppression.

BACKGROUND: Citrus huanglongbing (HLB) is a devastating disease caused by Candidatus Liberibacter asiaticus (CLas) that affects the citrus industry. In nature, CLas relies primarily on Diaphorina citri Kuwayama as its vector for dissemination. After D. citri ingests CLas-infected citrus, the pathogen infiltrates the insect's body, where it thrives, reproduces, and exerts regulatory control over the growth and metabolism of D. citri. Previous studies have shown that CLas alters the composition of proteins in the saliva of D. citri, but the functions of these proteins remain largely unknown. RESULTS: In this study, we detected two proteins (DcitSGP1 and DcitSGP3) with high expression levels in CLas-infected D. citri. Quantitative PCR and Western blotting analysis showed that the two proteins were highly expressed in the salivary glands and delivered into the host plant during feeding. Silencing the two genes significantly decreased the survival rate for D. citri, reduced phloem nutrition sucking and promoted jasmonic acid (JA) defenses in citrus. By contrast, after overexpressing the two genes in citrus, the expression levels of JA pathway-associated genes decreased. CONCLUSION: Our results suggest that CLas can indirectly suppress the defenses of citrus and support feeding by D. citri via increasing the levels of effectors in the insect's saliva. This discovery facilitates further research into the interaction between insect vectors and pathogens. © 2024 Society of Chemical Industry.

Antigenicity, epitope mapping, and intracellular distribution of the NSP7α protein of porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen that causes huge economic losses to the global pig industry. Nonstructural protein 7α (NSP7α) of PRRSV is highly conserved among different lineages of PRRSV and could be a potential target for the development of detection methods. In this study, NSP7α was expressed in prokaryote (Escherichia coli) and purified. An NSP7α-ab-ELISA detection method was established, the NSP7α-ab-ELISA has 93.1 % coincidence rate with IDEXX PRRS X3 ab test kit. NSP7α antibody was detected in pig serum by ELISA 14 days following PRRSV infection. Three monoclonal antibodies (4H9, 3F2, and C10) against NSP7α prepared by a hybridoma technique were used for epitope mapping by indirect immunofluorescence. The 4H9, 3F2, and C10 antibodies all recognized the C-terminal 72-149 amino acid region of NSP7α. 4H9 reacted with amino acids 135-143, but 3F2 and C10 did not react with any truncated polypeptide. In addition, by using the monoclonal antibodies, NSP7α was localized solely in the cytoplasm, while the N protein was distributed in the cytoplasm and nucleus. The collective findings of the antigenicity and epitope of NSP7α will be helpful for understanding the antigenicity of NSP7α and developing PRRSV diagnostic methods.

Regulation of soldier caste differentiation by microRNAs in Formosan subterranean termite (Coptotermes formosanus Shiraki).

The soldier caste is one of the most distinguished castes inside the termite colony. The mechanism of soldier caste differentiation has mainly been studied at the transcriptional level, but the function of microRNAs (miRNAs) in soldier caste differentiation is seldom studied. In this study, the workers of Coptotermes formosanus Shiraki were treated with methoprene, a juvenile hormone analog which can induce workers to transform into soldiers. The miRNomes of the methoprene-treated workers and the controls were sequenced. Then, the differentially expressed miRNAs (DEmiRs) were corrected with the differentially expressed genes DEGs to construct the DEmiR-DEG regulatory network. Afterwards, the DEmiR-regulated DEGs were subjected to GO enrichment and KEGG enrichment analysis. A total of 1,324 miRNAs were identified, among which 116 miRNAs were screened as DEmiRs between the methoprene-treated group and the control group. A total of 4,433 DEmiR-DEG pairs were obtained. No GO term was recognized as significant in the cellular component, molecular function, or biological process categories. The KEGG enrichment analysis of the DEmiR-regulated DEGs showed that the ribosome biogenesis in eukaryotes and circadian rhythm-fly pathways were enriched. This study demonstrates that DEmiRs and DEGs form a complex network regulating soldier caste differentiation in termites.

Gastrodin alleviates mitochondrial dysfunction by regulating SIRT3-mediated TFAM acetylation in vascular dementia.

BACKGROUND: Mitochondrial dysfunction is key to the pathogenesis of vascular dementia (VaD). Sirtuin-3 (SIRT3), an essential member of the sirtuins family, has been proven to be a critical sirtuin in regulating mitochondrial function. The phenolic glucoside gastrodin (GAS), a bioactive ingredient from Gastrodiae Rhizome (known in Chinese as Tian ma) demonstrates significant neuroprotective properties against central nervous system disorders; however, the precise mechanisms through which GAS modulates VaD remain elusive. PURPOSE: This study aims to investigate whether GAS confers a protective role against VaD, and to figure out the underlying molecular mechanisms. METHODS: A bilateral common carotid artery occlusion (BCCAO)-mediated chronic cerebral hypoperfusion (CCH) VaD rat model and a hypoxia model using HT22 cells were employed to investigate pharmacological properties of GAS in mitigating mitochondrial dysfunction. A SIRT3 agonist resveratrol (RES), a SIRT3 inhibitor 3-TYP and SIRT3-knockdown in vitro were used to explore the mechanism of GAS in association with SIRT3. The ability of SIRT3 to bind and deacetylate mitochondrial transcription factor A (TFAM) was detected by immunoprecipitation assay, and TFAM acetylation sites were further validated using mass spectrometry. RESULTS: GAS increased SIRT3 expression and ameliorated mitochondrial structure, mitochondrial respiration, mitochondrial dynamics along with upregulated TFAM, mitigating oxidative stress and senescence. Comparable results were noted with the SIRT3 agonist RES, indicating an impactful neuroprotection played by SIRT3. Specifically, the attenuation of SIRT3 expression through knockdown techniques or exposure to the SIRT3 inhibitor 3-TYP in HT22 cells markedly abrogated GAS-mediated mitochondrial rescuing function. Furthermore, our findings elucidate a novel facet: SIRT3 interacted with and deacetylated TFAM at the K5, K7, and K8 sites. Decreased SIRT3 is accompanied by hyper-acetylated TFAM. CONCLUSION: The present results were the first to demonstrate that the SIRT3/TFAM pathway is a protective target for reversing mitochondrial dysfunction in VaD. The findings suggest that GAS-mediated modulation of the SIRT3/TFAM pathway, a novel mechanism, could ameliorate CCH-induced VaD, offering a potentially beneficial therapeutic strategy for VaD.

Shotgun metagenomics reveals the gut microbial diversity and functions in Vespa mandarinia (Hymenoptera: Vespidae) at multiple life stages.

Wasps play important roles as predators and pollinators in the ecosystem. The Jingpo minority residing in Yunnan Province, China, has a traditional practice of using wine infused with mature wasps as a customary remedy for managing rheumatoid arthritis. The larva of the wasp is also a tasteful folk dish that has created a tremendous market. There is a paucity of survival knowledge, which has greatly restricted their potential applications in food and healthcare. Recent research has highlighted the importance of gut microbiota in insect growth. Nevertheless, there is still a lack of understanding regarding the composition, changes, and functions of the gut microbiota in Vespa mandarinia during development. In this research, the gut microbiota were investigated across three growth stages of Vespa mandarinia using a metagenomic technology. The result revealed that there are significant variations in the proportion of main gut microbes during the metamorphosis of Vespa mandarinia. Tenericutes were found to dominate during the larval stage, while Proteobacteria emerged as the dominant group post-pupation. Through a comprehensive analysis of the gut microbiota metagenome, this study revealed functional differences in the wasp gut microbiota at various growth stages. During the larval stage, the gut microbiota plays a central role in promoting metabolism. Following pupation, the gut microbiota exhibited diversified functions, likely due to the complex environments and diverse food sources encountered after metamorphosis. These functions included amino acid metabolism, compound degradation, and defense mechanisms. This research provides an extensive dataset on the gut microbiota during the metamorphosis of Vespa mandarinia, contributing to a deeper understanding of the influence of gut microbiota on wasp growth. Furthermore, this study uncovers a unique microbial treasure within insect guts, which is important for advancing the application of wasps in the fields of food and medicine.

The effect of high-power atrial fibrillation ablation on intraoperative acute pulmonary vein isolation and postoperative troponin levels / 中国医师杂志

Objective:To compare the effects of high-power and conventional power atrial fibrillation ablation on intraoperative acute pulmonary vein isolation, postoperative troponin levels, and atrial fibrillation recurrence.Methods:A retrospective selection was conducted on 105 patients with paroxysmal atrial fibrillation admitted to the Baoding NO.1 Central Hospital from January 2017 to December 2020. According to different treatment methods, they were divided into a high-power ablation group of 52 cases and a conventional power ablation group of 53 cases. The intraoperative rate of single circle acute pulmonary vein isolation, the recovery of electrical conduction after acute pulmonary vein isolation, and the location and number of points that need to be added were compared between the two groups; At the same time, two groups were compared in terms of surgical time, ablation time, surgical radiation exposure time and radiation dose, intraoperative complications postoperative cardiac troponin levels at 12 hours, and recurrence of atrial fibrillation within 1 year after ablation.Results:The intraoperative single loop pulmonary vein isolation rate and postoperative troponin levels in the high-power atrial fibrillation ablation group were higher than those in the conventional atrial fibrillation ablation group (all P<0.05). The surgical time, ablation time, and the number of sites and points that need to be added during surgery were less than those in the conventional atrial fibrillation ablation group (all P<0.05). There was no statistically significant difference in the incidence of intraoperative complications and postoperative atrial fibrillation recurrence between the two groups (all P>0.05). Conclusions:High power atrial fibrillation ablation has a higher single loop acute pulmonary vein isolation rate, fewer patch sites and points, shorter surgical time, and greater ablation damage compared to conventional ablation, and the clinical efficacy of the two groups is similar after surgery.

[Remediation Effect and Mechanism of Biochar in Combination with Nitrogen Fertilizer on Cd-contaminated Paddy Soil].

Cadmium (Cd) heavy metal pollution has posed serious threats to soil health and the safe production utilization of agricultural products. A pot experiment was conducted to study the effects of biochar (BC) and nitrogen fertilizer with three levels, namely 2.6 g·pot-1 (N1), 3.5 g·pot-1 (N2), 4.4 g·pot-1 (N3) biochar combined with nitrogen fertilizer (BCN1, BCN2, and BCN3), on soil Cd fractions, Cd enrichment, the transport of rice, and soil enzyme activity, as well as the changes in microbial community composition and complex interactions between microorganisms through high-throughput sequencing. The results showed that biochar combined with nitrogen fertilizer led to the transformation of Cd from the exchangeable state to the residue state, and the proportion of the exchangeable state was significantly reduced by 6.2%-14.7%; by contrast, the proportion of the residue state increased by 18.6%-26.4% relative to that in CK. In addition, singular treatments of nitrogen fertilizer enhanced the accumulation capacities of Cd in roots, which increased by 22%-33.5% compared with that in CK. By contrast, the BC and BCN treatments reduced Cd accumulation in roots and the transfer capacity from stems to rice husks and husk to rice. Furthermore, the BCN treatments promoted soil enzyme activities (urease, acid phosphatase, invertase, and catalase). MiSeq sequencing showed that BCN treatments increased the abundance of the main species of soil bacterial microbes (such as Acidobacteriales, Solibacterales, Pedosphaerales, and Nitrospirales). Moreover, co-occurrence network analysis showed that the complexity of the soil bacterial network was enhanced under the N, BC, and BCN treatments. Overall, biochar combined with nitrogen fertilizer reduced soil Cd availability, inhibited the capacity of Cd accumulation and the transport of rice, and improved the soil eco-environmental quality. Thus, using BCN could be a feasible practice for the remediation of Cd-polluted agricultural soil.

Gastrodin relieves cognitive impairment by regulating autophagy via PI3K/AKT signaling pathway in vascular dementia.

Vascular dementia (VaD), the second most common type of dementia, is attributed to lower cerebral blood flow. To date, there is still no available clinical treatment for VaD. The phenolic glucoside gastrodin (GAS) is known for its neuroprotective effects, but the role and mechanisms of action on VD remains unclear. In this study, we aim to investigate the neuroprotective role and underlying mechanisms of GAS on chronic cerebral hypoperfusion (CCH)-mediated VaD rats and hypoxia-induced injury of HT22 cells. The study showed that GAS relieved learning and memory deficits, ameliorated hippocampus histological lesions in VaD rats. Additionally, GAS down-regulated LC3II/I, Beclin-1 levels and up-regulated P62 level in VaD rats and hypoxia-injured HT22 cells. Notably, GAS rescued the phosphorylation of PI3K/AKT pathway-related proteins expression, which regulates autophagy. Mechanistic studies verify that YP-740, a PI3K agonist, significantly resulted in inhibition of excessive autophagy and apoptosis with no significant differences were observed in the YP-740 and GAS co-treatment. Meantime, we found that LY294002, a PI3K inhibitor, substantially abolished GAS-mediated neuroprotection. These results revealed that the effects of GAS on VaD are related to stimulating PI3K/AKT pathway-mediated autophagy, suggesting a potentially beneficial therapeutic strategy for VaD.

The therapeutic effect of wasp venom (Vespa magnifica, Smith) and its effective part on rheumatoid arthritis fibroblast-like synoviocytes through modulating inflammation, redox homeostasis and ferroptosis.

ETHNOPHARMACOLOGICAL RELEVANCE: Rheumatoid arthritis (RA) is a chronic inflammatory disease that is related to the aberrant proliferation of fibroblast-like synoviocytes (FLS). Wasp venom (WV, Vespa magnifica, Smith), an insect secretion, has been used to treat RA in Chinese Jingpo national minority's ancient prescription. However, the potential mechanisms haven't been clarified. AIM OF THE STUDY: The purposes of this paper were two-fold. First, to investigate which was the best anti-RA effective part of WV-I (molecular weight less than 3 kDa), WV-II (molecular weight 3-10 kDa) and WV-III (molecular weight more than 10 kDa) that were separated from WV. Second, to explore the underlying molecular mechanism of WV and WV-II that was best effective part in RA. MATERIALS AND METHODS: The wasps were electrically stimulated and the secretions were collected. WV-I, WV-II and WV-III were acquired by ultracentrifuge method according to molecular weight. Next, WV, WV-I, WV-II and WV-III were identified by HPLC. Functional annotation and pathway analysis of WV used to bioinformatics analysis. RNA-seq analyses were constructed to identify differentially expressed genes (DEGs). GO and KEGG pathway analyses were performed by Metascape database. STRING was used to analyze the PPI network from DEGs. Next, PPI network was visualized using Cytoscape that based on MCODE. The pivotal genes of PPI network and MCODE analysis were verified by qRT-PCR. Subsequently, MH7A cells were performed by MTT assay to evaluate the ability of inhibiting cell proliferation. Luciferase activity assay was conducted in HepG2/STAT1 or HepG2/STAT3 cells to assess STAT1/3 sensitivity of WV, WV-I, WV-II and WV-III. Additionally, interleukin (IL)-1ß and IL-6 expression levels were detected by ELISA kits. Intracellular thioredoxin reductase (TrxR) enzyme was evaluated by TrxR activity assay kit. ROS levels, lipid ROS levels and Mitochondrial membrane potential (MMP) were assessed by fluorescence probe. Cell apoptosis and MMP were measured by using flow cytometry. Furthermore, the key proteins of JAK/STAT signaling pathway, protein levels of TrxR and glutathione peroxidase 4 axis (GPX4) were examined by Western blotting assay. RESULTS: RNA-sequencing analysis of WV displayed be related to oxidation-reduction, inflammation and apoptosis. The data displayed that WV, WV-II and WV-III inhibited significantly cells proliferation in human MH7A cell line compared to WV-I treatment group, but WV-III had no significant suppressive effect on luciferase activity of STAT3 compared with IL-6-induced group. Combined with earlier reports that WV-III contained major allergens, we selected WV and WV-II further to study the mechanism of anti-RA. In addition, WV and WV-II decreased the level of IL-1ß and IL-6 in TNF-α-induced MH7A cells via inactivating of JAK/STAT signaling pathway. On the other hand, WV and WV-II down-regulated the TrxR activity to produce ROS and induce cell apoptosis. Furthermore, WV and WV-II could accumulate lipid ROS to induce GPX4-mediated ferroptosis. CONCLUSIONS: Taken together, the experimental results revealed that WV and WV-II were potential therapeutic agents for RA through modulating JAK/STAT signaling pathways, redox homeostasis and ferroptosis in MH7A cells. Of note, WV-II was an effective part and the predominant active monomer in WV-II will be further explored in the future.

Ethyl Gallate Isolated from Castanopsis cuspidata var. sieboldii Branches Inhibits Melanogenesis and Promotes Autophagy in B16F10 Cells.

The Castanopsis cuspidata var. sieboldii (CCS) plant grows predominantly in temperate regions of Asian countries, such as South Korea. Research on CCS has so far concentrated on the nutritional analysis, antioxidant activity, and anti-inflammation properties of its branches. However, the isolation of compounds and structural elucidation of effective single molecules remain unexplored, necessitating further exploration of CCS branches. Therefore, this study demonstrates the antioxidant and antimelanogenic activity of a single substance of ethyl gallate (EG) isolated from CCS branch extracts. Notably, the antimelanogenic (whitening) activity of EG extracted from CCS branches remains unexplored. Tyrosinase inhibition, kinetic enzyme assays, and molecular docking studies were conducted using mushroom tyrosinase in order to examine the antioxidant mechanism and antimelanin activity of EG in B16F10 melanoma cells. Nontoxic EG concentrations were found to be below 5 µg/mL. While EG significantly reduced the levels of whitening-associated proteins, p-CREB, and p-PKA, it dose-dependently inhibited the expression of TYR, TRP-1, TRP-2, and transcription factor (MITF). In addition, EG downregulated melanogenetic gene expression and activated autophagy signals. Therefore, EG extracted from CCS branches could serve as a novel functional cosmetic material with antimelanogenic and autophagy-enhancing activity.

Inspiratory muscle training can improve the breathing, balance and walking of persons with Parkinson′s disease / 中华物理医学与康复杂志

Objective:To observe any effect of threshold pressure loaded inspiratory muscle training on the balance of persons with Parkinson′s disease (PD).Methods:Forty-eight persons with PD were randomly divided into an observation group and a control group, each of 24. Both groups were given conventional neurological drug treatment and conventional rehabilitation training. The observation group additionally completed inspiratory muscle training using a threshold pressure load trainer, 5 days per week for 8 weeks. Before and after the treatment, both groups′ inspiratory muscle functioning was quantified using ultrasound to assess diaphragm mobility and thickness, and maximum inspiratory pressure (MIP). Balance was quantified using Trunk Injury Scale (TIS) scoring, the Berg Balance Scale (BBS), limits of stability (LOS), and the timed up and go test (TUGT). Walking was evaluated using the 10-metre walk test (10MWT) and the Dynamic Gait Index (DGI).Results:After the treatment all of the indicators had improved significantly in both groups, on average, but those of the observation group were then significantly better. Correlation analysis showed that the difference in MIP of the observation group before and after treatment was significantly negatively correlated with the TUGT and 10MWT times.Conclusion:Threshold pressure loaded inspiratory muscle training combined with conventional rehabilitation therapy significantly improves the inspiratory muscle strength, balance and walking of persons with PD.

Effect of hand controlled rhythm music therapy on unilateral spatial neglect after stroke / 中国康复理论与实践

ObjectiveTo observe the clinical effect of hand controlled rhythm music therapy on unilateral spatial neglect for stroke patients. MethodsFrom September, 2020 to September, 2022, 52 patients with unilateral spatial neglect after stroke in Wuxi Central Rehabilitation Hospital were randomly divided into control group (n = 26) and observation group (n = 26). Both groups accepted routine rehabilitation, and the observation group accepted hand controlled rhythm music therapy in addition, for eight weeks. Before and after treatment, the patients were assessed with Chinese Behavioral Inattention Test-Hong Kong version (CBIT-HK) routine tests (line crossing, letter cancellation, star cancellation, line bisection, figure and shape copying, and representational drawing) and modified Barthel Index (MBI). ResultsAfter treatment, six scores of CBIT-HK routine tests and the scores of MBI increased in both groups (|t| > 3.077, P < 0.05), and they were higher in the observation group than in the control group (|t| > 2.639, P < 0.05). ConclusionHand controlled rhythm music therapy could effectively alleviate the symptoms of unilateral spatial neglect after stroke, and improve the activities of daily living.

Recombinant characteristics, pathogenicity, and viral shedding of a novel PRRSV variant derived from twice inter-lineage recombination.

Porcine reproductive and respiratory syndrome (PRRS), caused by the PRRS virus (PRRSV), is a significant threat to the global pig industry. In this study, a novel recombinant PRRSV, SD043, was isolated from a pig farm experiencing disease in 2019. Phylogenetic analysis revealed that SD043 belonged to lineage 1 of PRRSV-2 while recombination analyses revealed that it is a recombinant virus from lineage 1 and lineage 8 strains. Based on further analysis, SD043 underwent recombination twice. Pathogenicity studies revealed that SD043 causes mild clinical symptoms, thymus atrophy, and severe histopathological lesions in the lungs. Notably, virus shedding in SD043-infected piglets was detectable at 10 days post-inoculation with a high viral load in the respiratory or digestive tract, indicating that the recombinant PRRSV appears to shed higher numbers of virus. Furthermore, genomic surveillance based on all available PRRSVs circulating in Shandong province revealed an increasing increase in recombinant PRRSV since 2015, with the recombinant pattern (between lineages 1 and 8) being the same as that of SD043. These findings enable a better understanding of the process of twice recombination and virus shedding of recombinant PRRSV and can strengthen the prevention and control of the PRRSV epidemic.

QSAR study of phenolic compounds and their anti-DPPH radical activity by discriminant analysis.

Phenolic compounds (PCs) could be applied to reduce reactive oxygen species (ROS) levels, and are used to prevent and treat diseases related to oxidative stress. QSAR study was applied to elucidate the relationship between the molecular descriptors and physicochemical properties of polyphenol analogues and their DPPH radical scavenging capability, to guide the design and discovery of highly-potent antioxidant substances more efficiently. PubMed database was used to collect 99 PCs with antioxidant activity, whereas, 105 negative PCs were found in ChEMBL database; their molecular descriptors were generated with Python's Rdkit package. While the molecular descriptors significantly related to the antioxidant activity of PCs were filtered by t-test. The prediction QSAR model was then established by discriminant analysis, and the obtained model was verified by the back-substitution and Leave-One-Out cross-validation methods along with heat map. It was revealed that the anti-DPPH radical activity of PCs was correlated with the drug-likeness and molecular fingerprints, physicochemical, topological, constitutional and electronic property. The established QSAR model could explicitly predict the antioxidant activity of polyphenols, thus were applicable to evaluate the potential of candidates as antioxidants.

Mycofabrication of Mycelium-Based Leather from Brown-Rot Fungi.

Sustainable substitutes for leather can be made from mushroom mycelium, which is an environmentally friendly alternative to animal and synthetic leather. Mycelium-based leather is derived from Polyporales, in which lignocellulosic material is used as the substrate. The plasticizing and crosslinking of mycelial mats with various reagents might affect the leather properties and mycelial architecture. This study investigated the physicochemical and mechanical properties of mycelium-based leather (MBL) samples, including the hygroscopic nature, thermal stability, cell wall chemistry, density, micromorphology, tensile strength, elongation rate, and Young's modulus. Micromorphological observations confirmed the mycelial networks and their binding performance, verifying their efficacy as a substitute leather. The most significant effects were observed after treatment with 20% polyethylene glycol, which resulted in an increase in Young's modulus and tensile strength. Furthermore, the samples generally exhibited a high density (1.35, 1.46 g/cm3) and tensile strength (7.21 ± 0.93, 8.49 ± 0.90 MPa), resembling leather. The tear strength reached as low as 0.5-0.8 N/mm. However, the tensile and tear strength may be affected by leather processing and the tuning of mycelial growth. Nevertheless, high-density mycelia are shown to be suitable for the production of MBL, while mycofabrication and strain selection are sustainable for novel industrial applications of MBL.

Laser decontamination microscopic process study on radioactive contaminations with Cs+ ion of 304 stainless steel surface.

The decommissioning of contaminated metal equipment in nuclear facilities may produce a wide range of radioactive waste. For metallic equipment like the primary loop, the radioactivity is mainly located in the oxide surface. Laser decontamination was performed on 304 stainless steel specimens with a stable isotope Cs contamination layer. Laser melting was used to create oxide layer on the surface of polished specimen for enhancing the penetration of Cs+ ion. The interaction between laser and matter (contamination, oxide and substrate) was studied by the stratification theory considering the difference in the thickness of contamination layer. At higher pulse duration (τp = 5ns), laser decontamination is mainly caused by thermal effects. The metal near oxide layer melts and vaporizes to form a molten pool and crater. For short pulse duration (τp = 1ns), the removal of surface contaminations mainly depends on thermal effect and stress wave, CsCl particles were removed by vaporization; however, oxide layer was stripped from the substrate in the form of solid fragment. For ultra-short pulse duration (τp = 150ps), the oxide layer has been partially ablated. Most of the heat absorbed by γ (austenite) is used for heating and evaporation to form porous structure, while the great mass of heat absorbed by M (martensite) is used for thermal diffusion. Therefore, the M regions only form a dynamic molten pool on its surface without vaporization.

Rapid visual detection of porcine reproductive and respiratory syndrome virus via recombinase polymerase amplification combined with a lateral flow dipstick.

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically devastating infectious diseases in the global swine industry. A rapid and sensitive on-site detection method for PRRS virus (PRRSV) is critically important for diagnosing PRRS. In this study, we established a method that combines reverse transcription recombinase polymerase amplification (RT-RPA) with a lateral flow dipstick (LFD) for detecting North American PRRSV (PRRSV-2). The primers and probe were designed based on the conserved region of all complete PRRSV-2 genomic sequences available in China (n = 512) from 1996 to 2020. The detection limit of the assay was 5.6 × 10-1 median tissue culture infection dose (TCID50) per reaction within 30 min at 42 °C, which was more sensitive than that of reverse transcription polymerase chain reaction (RT-PCR) (5.6 TCID50 per reaction). The assay was highly specific for the epidemic lineages of PRRSV-2 in China and did not cross-react with pseudorabies virus, porcine circovirus 2, classical swine fever virus, or porcine epidemic diarrhea virus. The assay performance was evaluated by testing 179 samples and comparing the results with those of quantitative RT-PCR (RT-qPCR). The results showed that the detection coincidence rate of RT-RPA and RT-qPCR was 100% when the cycle threshold values of RT-qPCR were < 32. The assay provides a new alternative for simple and reliable detection of PRRSV-2 and has great potential for application in the field.