421 research outputs found

    Transmissible gastroenteritis virus: Identification of M protein-binding peptide ligands with antiviral and diagnostic potential

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    The membrane (M) protein is one of the major structural proteins of coronavirus particles. In this study, the M protein of transmissible gastroenteritis virus (TGEV) was used to biopan a 12-mer phage display random peptide library. Three phages expressing TGEV-M-binding peptides were identified and characterized in more depth. A phage-based immunosorbent assay (phage-ELISA) capable of differentiating TGEV from other coronaviruses was developed using one phage, phTGEV-M7, as antigen. When the phage-ELISA was compared to conventional antibody-based ELISA for detecting infections, phage-ELISA exhibited greater sensitivity. A chemically synthesized, TGEV-M7 peptide (pepTGEV-M7; HALTPIKYIPPG) was evaluated for antiviral activity. Plaque-reduction assays revealed that pepTGEV-M7 was able to prevent TGEV infection in vitro (p \u3c 0.01) following pretreatment of the virus with the peptide. Indirect immunofluorescence and real-time RT-PCR confirmed the inhibitory effects of the peptide. These results indicate that pepTGEV-M7 might be utilized for virus-specific diagnostics and treatment

    Transmissible gastroenteritis virus: Identification of M protein-binding peptide ligands with antiviral and diagnostic potential

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    The membrane (M) protein is one of the major structural proteins of coronavirus particles. In this study, the M protein of transmissible gastroenteritis virus (TGEV) was used to biopan a 12-mer phage display random peptide library. Three phages expressing TGEV-M-binding peptides were identified and characterized in more depth. A phage-based immunosorbent assay (phage-ELISA) capable of differentiating TGEV from other coronaviruses was developed using one phage, phTGEV-M7, as antigen. When the phage-ELISA was compared to conventional antibody-based ELISA for detecting infections, phage-ELISA exhibited greater sensitivity. A chemically synthesized, TGEV-M7 peptide (pepTGEV-M7; HALTPIKYIPPG) was evaluated for antiviral activity. Plaque-reduction assays revealed that pepTGEV-M7 was able to prevent TGEV infection in vitro (p \u3c 0.01) following pretreatment of the virus with the peptide. Indirect immunofluorescence and real-time RT-PCR confirmed the inhibitory effects of the peptide. These results indicate that pepTGEV-M7 might be utilized for virus-specific diagnostics and treatment

    Stability of stope structure under different mining methods

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    The ore body has a great influence on the stability of surrounding rock and mining safety under different mining modes, and the reasonable selection of mining mode depends on other characteristics, such as ore structure surface feature, rock mass mechanical property, and ground stress distribution. Given the insufficient mining research data, this study establishes a 3D model by using the FLAC3D calculation program. Through numerical simulation and other technical means, a preliminary study on plastic and minimum stress changes during horizontal pillar mining, stress changes under different mining modes, and the effect comparison of full filling mining modes is conducted. Results show that the surrounding rock at the corner of pillar 1 is damaged, the plastic zone decreases, and the minimum stress in each working procedure increases slightly. The area of the plastic zone in alternate mining is smaller to that in continuous mining. This study provides a theoretical basis for ore body mining

    Preparation and properties of asphalt binders modified by THFS extracted from direct coal liquefaction residue

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    This paper aims to study the preparation and viscoelastic properties of asphalt binder modified by tetrahydrofuran soluble fraction (THFS) extracted from direct coal liquefaction residue. The modified asphalt binders, which blended with SK-90 (control asphalt binder) and 4%, 6%, 8% and 10% THFS (by weight of SK-90), were fabricated. The preparation process for asphalt binder was optimized in terms of the orthogonal array test strategy and gray correlation analysis results. The properties of asphalt binder were measured by applying Penetration performance grade and Superpave performance grade specifications. In addition, the temperature step and frequency sweep test in Dynamic Shear Rheometer were conducted to predict the rheological behavior, temperature and frequency susceptibility of asphalt binder. The test results suggested the optimal preparation process, such as 150 °C shearing temperature, 45 min shearing time and 4000 rpm shearing rate. Subsequently, the addition of THFS was beneficial in increasing the high-temperature properties but decreased the low-temperature properties and resistance to fatigue. The content analysis of THFS showed the percentage of 4~6% achieved a balance in the high-and-low temperature properties of asphalt binder. The asphalt binder with higher THFS content exhibited higher resistance to rutting and less sensitivity to frequency and temperature

    Ejecta-circumstellar medium interaction in high-density environment contribution to kilonova emission: Application to GRB 191019A

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    The nearby long-duration GRB 191019A recently detected by Swift lacks an associated supernova and belongs to a host galaxy with little star formation activity, suggesting that the origin of this burst is the result of a merger of two compact objects with dynamical interactions in a high-density medium of an active galactic nucleus. Given the potential motivation of this event, and given that it occurs in such a high-density environment, the ejecta-circumstellar medium (CSM) interaction cannot be ignored as possibly contributing to the kilonova emission. Here, we theoretically calculate the kilonova emission by considering the contribution of the ejecta-CSM interaction in a high-density environment. We find that the contribution to the kilonova emission from the ejecta-CSM interaction will dominate at a later time, and a smaller ejecta mass will have a stronger kilonova emission from the ejecta-CSM interaction. Moreover, we try to apply it to GRB 191019A, but we find that it is difficult to identify the possible kilonova emission from the observations, due to the contribution of the bright host galaxy. On the other hand, less injected mass (less than Mej=2×10−5M⊙M_{\rm ej}=2\times10^{-5}M_{\odot}) will be required if one can detect the kilonova emission associated with a GRB 191019A-like event in the future. The {\em r}-process-powered and spin energy contributions from the magnetar are also discussed.Comment: 10 pages, 6 figures, updated the rederence list. ApJ in press, and matched with the published veriso

    Synchronous Detection of BPV and BVDV with Duplex Taqman qPCR Method

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    Background: Bovine parvovirus (BPV) and bovine viral diarrhea virus (BVDV) are commonly etiologies causing diarrhea in dairy herds. BPV is a member of bocaparvovirus genus with a non-enveloped capsid. BVDV, belonging to Pestivirus genus in Flaviviridae, possesses a single-stranded RNA, and is classified into BVDV-1 and BVDV-2 genotypes according to the 5’UTR sequence. 21 genetic groups of BVDV-1 and four groups of BVDV-2 have been found. Diagnosis of viral diarrhea is often relied on virus detection by isolation or detection of serum antibody. The main objective of the present study was to establish a duplex real time PCR (qPCR) based on Taqman probe to detect synchronously BPV and BVDV. Materials, Methods & Results: TaqMan probe and primers were designed and synthesized from the sequences of conserved 5′ - untranslated regions (5′ UTR) of Haden strain of BPV and NADL strain of BVDV. The cDNAs were transcribed in vitro to make standard curves before optimizing the assay. DNA/PCR products were ligated into pMD18-T vector, and then used to transfer BL-21 competent cells to acquire the recombinant plasmids of pMD18-T-BPV and pMD18-T-BVDV. Optimum reaction conditions were comparatively selected. The sensitivity, specificity and reproducibility of TaqMan probe qRT-PCR were evaluated respectively. The results showed the concentrations of pMD18-T-BPV or pMD18-T-BVDV were 2.0 × 1010 DNA copies/μL, respectively. A duplex Taqman qPCR method was developed by optimizing the amplification conditions to simultaneously detect BPV and BVDV. The assay targets at highly conserved VP2 gene of BPV and 5′ UTR gene of BVDV. This qPCR assay was assessed for specificity and sensitivity using DNA of BPV and cDNA of BVDV. For clinical validation, 308 samples were tested from clinically diarrhea calves. The results showed that optimum annealing temperature was achieved in 43.2 ℃ fro duplex BPV and BPIV. Dynamic curves and standard curves were created following amplification of recombinant plasmids using the optimized duplex Taqman BPV and BVDV, with an amplification efficiency of 95.69%. Duplex Taqman qPCR could only detect DNA of BPV and cDNA of BVDV with a strong specificity. The detection limitation was as low as 2.0 × 102 copies/μL of pMD18-T-BPV plasmid and 2.0 × 101 copies/μL for pMD18-T-BVDV plasmid, respectively. Sensitivity of detection was 100-fold higher than conventional PCR. Duplex Taqman qPCR had excellent repeatability or stability with less than 1.2% of intra-assay and inter-assay. 35 and 47 positive feces samples were identified using duplex Taqman qPCR in comparison to 30 and 42 positives for universal PCR, respectively. Discussion: The bovine viral diarrhea virus (BVDV) is a key pathogenic factor in bovine diarrhea. Currently, few effective measures are available for the treatment or prevention for BVDV and BPV infections in animals. The technique was proven to be repeatable and linear over a range of at least 5 magnitudes, from 101 to 105 RNA/DNA copies, thus ensuring an accurate measurement of BPV DNA and BVDV RNA loads in clinical samples. In conclusion, a duplex Taqman qPCR was established for detecting simultaneously BPV and BVDV. Taqman qPCR method was rapid and specific assay. This assay was 100-fold sensitive than conventional PCR. It will be propitious to rapidly and differentially diagnose pathogens of viral diarrhea of dairy farms. Taqman qPCR method was rapid and specific assay and had a sensitivity of 2.0 copies/μL

    Transcriptome profile of halofuginone resistant and sensitive strains of Eimeria tenella

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    The antiparasitic drug halofuginone is important for controlling apicomplexan parasites. However, the occurrence of halofuginone resistance is a major obstacle for it to the treatment of apicomplexan parasites. Current studies have identified the molecular marker and drug resistance mechanisms of halofuginone in Plasmodium falciparum. In this study, we tried to use transcriptomic data to explore resistance mechanisms of halofuginone in apicomplexan parasites of the genus Eimeria (Apicomplexa: Eimeriidae). After halofuginone treatment of E. tenella parasites, transcriptome analysis was performed using samples derived from both resistant and sensitive strains. In the sensitive group, DEGs associated with enzymes were significantly downregulated, whereas the DNA damaging process was upregulated after halofuginone treatment, revealing the mechanism of halofuginone-induced parasite death. In addition, 1,325 differentially expressed genes (DEGs) were detected between halofuginone resistant and sensitive strains, and the DEGs related to translation were significantly downregulated after halofuginone induction. Overall, our results provide a gene expression profile for further studies on the mechanism of halofuginone resistance in E. tenella

    Genistein-3′-sulfonic acid dihydrate

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    In the title compound [systematic name: 5-(5,7-dihydr­oxy-4-oxo-4H-chromen­yl)-2-hydroxy­benzene­sulfonic acid dihydrate], C15H10O8S·2H2O, the benzopyran­one ring is not coplanar with the phenyl ring, the dihedral angle between them being 41.35 (3)°. No H atom was placed on the sulphonic acid group because it was not possible to distinguish between the two S=O bonds and the S—O bond. In the crystal, the mol­ecules are linked by classical O—H⋯O and C—H⋯O intra- and inter­molecular hydrogen bonds and aromatic π–π stacking inter­actions [centroid–centroid distance of 3.4523 (14) Å between the 1, 4-pyran­one rings and the benzene rings, and 3.6337 (14) Å between the benzene rings] into a supra­molecular structure
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