20 research outputs found

    Porcine RIG-I and MDA5 Signaling CARD Domains Exert Similar Antiviral Function Against Different Viruses

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    The RIG-I-like receptors (RLRs) RIG-I and MDA5 play critical roles in sensing and fighting viral infections. Although RIG-I and MDA5 have similar molecular structures, these two receptors have distinct features during activation. Further, the signaling domains of the N terminal CARD domains (CARDs) in RIG-I and MDA5 share poor similarity. Therefore, we wonder whether the CARDs of RIG-I and MDA5 play similar roles in signaling and antiviral function. Here we expressed porcine RIG-I and MDA5 CARDs in 293T cells and porcine alveolar macrophages and found that MDA5 CARDs exhibit higher expression and stronger signaling activity than RIG-I CARDs. Nevertheless, both RIG-I and MDA5 CARDs exert comparable antiviral function against several viruses. Transcriptome analysis showed that MDA5 CARDs are more effective in regulating downstream genes. However, in the presence of virus, both RIG-I and MDA5 CARDs exhibit similar effects on downstream gene transcriptions, reflecting their antiviral function

    Analytical Model for Load–Slip Relationship of Perfobond Shear Connector Based on Push-Out Test

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    In composite structures, the perfobond connector is an alternative type of shear connector which consists of a steel plate with a certain number of holes. The load–slip relationship is critical for structural analysis and numerical simulation of composite structures using perfobond connectors. In this study, push-out tests were conducted on 72 specimens to obtain the load–slip behaviors of perfobond connectors. Based on the test results, parametric study was performed to analyze the effects of changing the hole geometry, the concrete strength, the configuration of the rebar in hole, the dimensions of the perfobond rib, and the size of the concrete slab. Furthermore, the characteristics and physical meanings of the load–slip curves were analyzed, and the limits and conditions for theoretical expressions were derived. Finally, an analytical model was proposed to express the load–slip relationship of perfobond connectors covering a wide range of design variables

    Experimental and Parametric Study on the Pull-Out Resistance of a Notched Perfobond Shear Connector

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    To ease the installation of perforating rebars through multi-holes, an alternative notched perfobond shear connector was proposed by cutting out the hole edge. This paper presents the test results of six pull-out specimens with conventional and notched perfobond shear connectors. The objective was to compare the failure modes and pull-out behaviors of perfobond shear connectors using circular holes and notched holes. Furthermore, the explicit finite element method was introduced and validated to generate parametric results for pull-out tests of notched perfobond shear connectors. A total of 33 parametric simulations were performed to further study the influences of several variables, including the hole diameter, the cut width, the perfobond thickness, the concrete strength, the diameter and strength of the rebar, and the strength of the structural steel. The experimental and numerical results were used to evaluate the previous equations for perfobond shear connectors. Finally, an alternative equation was proposed to estimate the pull-out resistance of notched perfobond shear connectors

    Experimental and Numerical Study on Shear Resistance of Notched Perfobond Shear Connector

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    In steel and concrete composite bridges, it is difficult to perforate the reinforcing bars through the circular holes of conventional perfobond shear connectors with multi-ribs. To ease the installation of perforating rebars, an alternative notched perfobond shear connector was proposed by cutting out the edge of the circular hole. This paper presents the push-out test results of six specimens which were fabricated and loaded to failure. The main purpose was to compare the failure mode, shear capacity and slip behavior of perfobond shear connectors using circular holes and notched holes. Furthermore, 43 nonlinear finite element simulations were performed to further study the effects of several variables, including the hole diameter, the hole distance, the hole number, the cut width, the perfobond thickness, the concrete strength, the rebar diameter, the rebar strength, and the steel strength. The parametric results were generated to evaluate the shear capacity equations for perfobond shear connectors. Finally, an analytical model was developed to estimate the shear capacity of notched perfobond shear connectors

    Nitric Oxide Enhancing Resistance to PEG-Induced Water Deficiency is Associated with the Primary Photosynthesis Reaction in Triticum aestivum L.

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    Photosynthesis is affected by water-deficiency (WD) stress, and nitric oxide (NO) is a free radical that participates in the photosynthesis process. Previous studies have suggested that NO regulates excitation-energy distribution of photosynthesis under WD stress. Here, quantitative phosphoproteomic profiling was conducted using iTRAQ. Differentially phosphorylated protein species (DEPs) were identified in leaves of NO- or polyethylene glycol (PEG)-treated wheat seedlings (D), and in control seedlings. From 1396 unique phosphoproteins, 2257 unique phosphorylated peptides and 2416 phosphorylation sites were identified. Of these, 96 DEPs displayed significant changes (≥1.50-fold, p < 0.01). These DEPs are involved in photosynthesis, signal transduction, etc. Furthermore, phosphorylation of several DEPs was upregulated by both D and NO treatments, but downregulated only in NO treatment. These differences affected the chlorophyll A–B binding protein, chloroplast post-illumination chlorophyll-fluorescence-increase protein, and SNT7, implying that NO indirectly regulated the absorption and transport of light energy in photosynthesis in response to WD stress. The significant difference of chlorophyll (Chl) content, Chl a fluorescence-transient, photosynthesis index, and trapping and transport of light energy further indicated that exogenous NO under D stress enhanced the primary photosynthesis reaction compared to D treatment. A putative pathway is proposed to elucidate NO regulation of the primary reaction of photosynthesis under WD

    Porcine IFI16 Negatively Regulates cGAS Signaling Through the Restriction of DNA Binding and Stimulation

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    The innate immunity DNA sensors have drawn much attention due to their significant importance against the infections with DNA viruses and intracellular bacteria. Among the multiple DNA sensors, IFI16, and cGAS are the two major ones, subjected to extensive studies. However, these two DNA sensors in livestock animals have not been well defined. Here, we studied the porcine IFI16 and cGAS, and their mutual relationship. We found that both enable STING-dependent signaling to downstream IFN upon DNA transfection and HSV-1 infection, and cGAS plays a major role in DNA signaling. In terms of their relationship, IFI16 appeared to interfere with cGAS signaling as deduced from both transfected and knockout cells. Mechanistically, IFI16 competitively binds with agonist DNA and signaling adaptor STING and thereby influences second messenger cGAMP production and downstream gene transcription. Furthermore, the HIN2 domain of porcine IFI16 harbored most of its activity and mediated cGAS inhibition. Thus, this study provides a unique insight into the porcine DNA sensing system

    Development of Specific Monoclonal Antibodies against Porcine RIG-I-like Receptors Revealed the Species Specificity

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    The RIG-I-like receptors (RLRs) play critical roles in sensing and combating viral infections, particularly RNA virus infections. However, there is a dearth of research on livestock RLRs due to a lack of specific antibodies. In this study, we purified porcine RLR proteins and developed monoclonal antibodies (mAbs) against porcine RLR members RIG-I, MDA5 and LGP2, for which one, one and two hybridomas were obtained, respectively. The porcine RIG-I and MDA5 mAbs each targeted the regions beyond the N-terminal CARDs domains, whereas the two LGP2 mAbs were both directed to the N-terminal helicase ATP binding domain in the Western blotting. In addition, all of the porcine RLR mAbs recognized the corresponding cytoplasmic RLR proteins in the immunofluorescence and immunochemistry assays. Importantly, both RIG-I and MDA5 mAbs are porcine specific, without demonstrating any cross-reactions with the human counterparts. As for the two LGP2 mAbs, one is porcine specific, whereas another one reacts with both porcine and human LGP2. Thus, our study not only provides useful tools for porcine RLR antiviral signaling research, but also reveals the porcine species specificity, giving significant insights into porcine innate immunity and immune biology

    Chicken DNA Sensing cGAS-STING Signal Pathway Mediates Broad Spectrum Antiviral Functions

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    The innate DNA sensing receptors are one family of pattern recognition receptors and play important roles in antiviral infections, especially DNA viral infections. Among the multiple DNA sensors, cGAS has been studied intensively and is most defined in mammals. However, DNA sensors in chickens have not been much studied, and the chicken cGAS is still not fully understood. In this study, we investigated the chicken cGAS-STING signal axis, revealed its synergistic activity, species-specificity, and the signal essential sites in cGAS. Importantly, both cGAS and STING exhibited antiviral effects against DNA viruses, retroviruses, and RNA viruses, suggesting the broad range antiviral functions and the critical roles in chicken innate immunity

    Reduning injection for fever, rash, and ulcers in children with mild hand, foot, and mouth disease: a randomized controlled clinical study

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    AbstractObjectiveTo assess the efficacy and safety of Reduning injection for fever, rash, and ulcers in children with mild hand, foot, and mouth disease (HFMD).MethodsA stratified-block randomized, double-blind, parallel-controlled, and multicenter clinical trial was conducted with 360 patients in five hospitals across China: Quanzhou Children's Hospital, Shijiazhuang No. 5 Hospital, Shanghai Public Health Centre, Hunan Provincial Children's Hospital, and Kaifeng Children's Hospital. Patients were randomized into three groups with 120 in each. Group A was treated with Western Medicine, group B with Reduning injection, a Chinese herbal medicine, and group C with both Reduning injection and Western Medicine. Results were compared for treatment efficacy and safety on HFMD. The clinical outcomes were observed as follows: fever and onset time of antifebrile effect (time to bring the body temperature down ≥0.5°C after medication); cumulative time for fever recovery (body temperature recovering to normal and lasting more than 24 h without medication); cumulative time for rash disappearance (without new rashes or ulcers appearing and the original ones fading away); and cumulative time for mouth ulcer disappearance.ResultsFor the onset time of the antifebrile effect, there was no statistical difference between groups A and B (P>0.05) and groups B and C (P> 0.05). However, there was a statistical difference between groups A and C (P<0.05), and the effect in group C was the best. For the cumulative time for rash disappearance, there was no statistical difference between groups A and B (P>0.05). There were statistical differences between groups A and C, and groups B and C (P<0.05), and the effect in group C was the best. For the cumulative time for mouth ulcers disappearance, there were no statistical differences among the three groups (P>0.05).ConclusionReduning injection with Western Medicine for symptomatic treatment is most effective for mild HFMD. No adverse reactions were observed
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