Simulation on the Resistance of the Filter Media with Lattice Boltzmann Method

To simulate the resistance of fibrous air filter media it is first necessary to develop an accurate simulation model for the gas flow through the media structure. We present an approach making only one basic simplification to the media geometry to investigate the flow through micro-scale porous geometries with the slip and no-slip boundary conditions by means of Lattice Boltzmann Method (LBM). Computed air flow resistance predictions for two kinds of filter media are compared with experimental data and their validity is discussed

Screening and characterization of a novel linear B-cell epitope on orf virus F1L protein

BackgroundOrf, also known as contagious ecthyma (CE), is an acute, contagious zoonotic disease caused by the orf virus (ORFV). The F1L protein is a major immunodominant protein on the surface of ORFV and can induce the production of neutralizing antibodies.MethodsThe prokaryotic expression system was used to produce the recombinant F1L protein of ORFV, which was subsequently purified and used to immunize mice. Positive hybridoma clones were screened using an indirect enzyme-linked immunosorbent assay (ELISA). The reactivity and specificity of the monoclonal antibody (mAb) were verified through Western blot and indirect immunofluorescence (IFA). The linear antigenic epitope specific to the mAb was identified through Western blot, using truncated F1L proteins expressed in eukaryotic cells. A multiple sequence alignment of the ORFV reference strains was performed to evaluate the degree of conservation of the identified epitope.ResultsAfter three rounds of subcloning, a mAb named Ba-F1L was produced. Ba-F1L was found to react with both the exogenously expressed F1L protein and the native F1L protein from ORFV-infected cells, as confirmed by Western blot and IFA. The mAb recognized the core epitope 103CKSTCPKEM111, which is highly conserved among various ORFV strains, as shown by homologous sequence alignment.ConclusionThe mAb produced in the present study can be used as a diagnostic reagent for detecting ORFV and as a basic tool for exploring the mechanisms of orf pathogenesis. In addition, the identified linear epitope may be valuable for the development of epitope-based vaccines

Molecular detection and phylogenetic analysis of Orf viruses from goats in Jiangxi province, China

Orf is a zoonosis caused by the Orf virus (ORFV), which is endemic in goats, sheep, and wild ruminants worldwide. Orf infection is prevalent in China, with outbreaks reported in several provinces. Currently, there is limited information available regarding the characterization of ORFV strains in Jiangxi province. This study investigated an acute outbreak of Orf that occurred in 2021 in a goat herd in the Jiangxi province of China. Clinical signs in this case included lesions on the lips, nose, and inside the mouth. The presence of ORFV was confirmed from tissue samples by polymerase chain reaction (PCR). The nucleotide sequences of the B2L and F1L genes were fully sequenced and used to construct phylogenetic trees. The results of this investigation identified the ORFV JXxy2021 as the cause of the outbreak. The phylogenetic analysis revealed that the ORFV strain JXxy2021 had the highest similarity to the ORFV strains GO and FJ-SL from the neighboring province of Fujian. This suggests that JXxy2021 was likely transmitted from Fujian province. The results have provided valuable information on the genetic characteristics of JXxy2021 and the endemic situations of Orf in China

An investigation on failure behavior of semi-flexible composite mixture at different temperatures

Semi-flexible composite mixture (SFCM) is a kind of pavement material formed by pouring cement-based grout material into a porous asphalt mixture with air voids from 20% to 30%. SFCM is widely used for its outstanding anti-rutting performance. Its mechanical performance is complicated due to its heterogeneity and interlocking structure. According to the present study, asphalt deforms at different temperatures, whereas cement-based grout has no similar characteristics. Rare research focuses on the temperature-based performance of SFCM. Therefore, the study was on the thermal performance of SFCM by seven open-graded asphalt mixture skeletons with different porosities and two types of grouts with early strength (ES) and high strength (HS). The test temperatures ranged from −10 ​°C to 60 ​°C. The mechanical investigation was performed using the semi-circular-bending (SCB) and beam bending tests. The strain sensor was used for analyzing the thermal performance of SFCM. The results show that the temperature significantly affected the SFCM's performance. The porosity was selected for three sections based on the trend of fracture energy (Gf) curves at 25 ​°C. The turning points were the porosity values of 20% and 26%. The initiation slope during elastic deformation increases with the porosity increase. This trend was more evident at intermediate temperature. The shrink strain of SFCM was lower than that of the usual asphalt mixture (AC). The thermal stress of the SFCM filled with HS (HS-SFCM) was higher than that of the SFCM filled with ES (ES-SFCM) at −10 ​°C. Moreover, the thermal failure characteristics of SFCM were influenced by porosity

Investigation on the Influences of Curing Time on the Cracking Resistance of Semiflexible Pavement Mixture

Semiflexible pavement (SFP) is constructed by pouring grouting material into porous asphalt (PA) mixture. SFP has been widely used to address the rutting distress issues across China in recent years. However, studies on its cracking resistance are limited and the failure mechanism of the SFP mixture has not been fully explored nor understood in a comprehensive way. Moreover, the influences of the curing time on the cracking property of the SFP mixture are still not clear. To this end, the strength development and shrinkage properties of grouting materials are determined by utilizing the three-point beam bending test and the shrinkage test. The semicircular bending (SCB) test and the scanning electron microscope-energy-dispersive spectrum (SEM-EDS) are conducted in this study to investigate the cracking resistance and failure mechanism of SFP mixtures with different curing days. Results show that both the strength and shrinkage of grouting materials would develop as the curing time was extended from 0 days to 14 days. SCB test results show that SFP mixtures have higher tensile strength but a lower flexibility index (FI) than PA mixture. It is found that the cracking resistance of SFP mixture is influenced by both the grouting materials’ strength and shrinkage. SEM-EDS analysis demonstrates that the cement-asphalt interface is a stress concentration site and therefore is the weak zone where cracks would initially develop. The microcracks found in the interface zone with different curing days may contribute to the decline of the SFP mixture’s anticracking ability. This study sheds light on the further application of SFP in practical projects

Fatigue Resistance and Cracking Mechanism of Semi-Flexible Pavement Mixture

Semi-flexible pavement (SFP) is widely used in recent years because of its good rutting resistance, but it is easy to crack under traffic loads. A large number of studies are aimed at improving its crack resistance. However, the understanding of its fatigue resistance and fatigue-cracking mechanism is limited. Therefore, the semi-circular bending (SCB) fatigue test is used to evaluate the fatigue resistance of the SFP mixture. SCB fatigue tests under different temperature values and stress ratio were used to characterize the fatigue life of the SFP mixture, and its laboratory fatigue prediction model was established. The distribution of various phases of the SFP mixture in the fracture surface was analyzed by digital image processing technology, and its fatigue cracking mechanism was analyzed. The results show that the SFP mixture has better fatigue resistance under low temperature and low stress ratio, while its fatigue resistance under other environmental and load conditions is worse than that of asphalt mixture. The main reason for the poor fatigue resistance of the SFP mixture is the poor deformation capacity and low strength of grouting materials. Furthermore, the performance difference between grouting material and the asphalt binder is large, which leads to the difference of fatigue cracking mechanism of the SFP mixture under different conditions. Under the fatigue load, the weak position of the SFP mixture at a low temperature is asphalt binder and its interface with other materials, while at medium and high temperatures, the weak position of the SFP mixture is inside the grouting material. The research provides a basis for the calculation of the service life of the SFP structure, provides a reference for the improvement direction of the SFP mixture composition and internal structure

Synthesis and electrochemistry performance of CuO-functionalized CNTs-rGO nanocomposites for highly sensitive hydrazine detection

In this paper, we have synthesized the cupric oxide functionalized carbon nanotube-reduced graphene oxide (CuO/CNTs-rGO) nanocomposites by a facile one-pot method. The obtained samples were characterized by transmission electron microscope (TEM), energy-dispersive spectroscopy (EDS), and X-ray powder diffraction (XRD) techniques. To investigate the electrochemical properties, the as-fabricated sensors were tested toward hydrazine detection by cyclic voltammetry (CV) and amperometry methods. The measured results demonstrate that the CuO/CNTs-rGO nanocomposites sensor shows a sensitivity of 4.28 mu A center dot mu M-1 center dot cm(-2), a linear range of 1.2-430 mu M, and detection limit of 0.2 mu M toward hydrazine. The enhanced electrocatalytic activity can be attributed to the catalytic properties of CuO and synergistic effect of the ternary nanocomposites. Meanwhile, the as-fabricated CuO/CNTs-rGO sensor also displays good selectivity and long-term stability, which implies its feasibility for practical application

Central role of cellular senescence in TSLP-induced airway remodeling in asthma.

BACKGROUND:Airway remodeling is a repair process that occurs after injury resulting in increased airway hyper-responsiveness in asthma. Thymic stromal lymphopoietin (TSLP), a vital cytokine, plays a critical role in orchestrating, perpetuating and amplifying the inflammatory response in asthma. TSLP is also a critical factor in airway remodeling in asthma. OBJECTIVES:To examine the role of TSLP-induced cellular senescence in airway remodeling of asthma in vitro and in vivo. METHODS:Cellular senescence and airway remodeling were examined in lung specimens from patients with asthma using immunohischemical analysis. Both small molecule and shRNA approaches that target the senescent signaling pathways were used to explore the role of cellular senescence in TSLP-induced airway remodeling in vitro. Senescence-Associated β-galactosidase (SA-β-Gal) staining, and BrdU assays were used to detect cellular senescence. In addition, the Stat3-targeted inhibitor, WP1066, was evaluated in an asthma mouse model to determine if inhibiting cellular senescence influences airway remodeling in asthma. RESULTS:Activation of cellular senescence as evidenced by checkpoint activation and cell cycle arrest was detected in airway epithelia samples from patients with asthma. Furthermore, TSLP-induced cellular senescence was required for airway remodeling in vitro. In addition, a mouse asthma model indicates that inhibiting cellular senescence blocks airway remodeling and relieves airway resistance. CONCLUSION:TSLP stimulation can induce cellular senescence during airway remodeling in asthma. Inhibiting the signaling pathways of cellular senescence overcomes TSLP-induced airway remodeling

Coplanar Asymmetry Transformer Distributed Modeling for X-Band Drive Power Amplifier Design on GaN Process

In this paper, a methodology for designing a distributed model for coplanar asymmetry transformer on gallium nitride (GaN) process is proposed, which can accurately characterize the transformer’s feature up to a millimeter-wave band. The paper analyses a transformer-based matching circuit and proposes a practical transformer design procedure. A two stage, transformer matching based X-band power amplifier (PA) is reported here. Using the proposed transformer model and correlated transformer design procedure can sharply reduce schematic design period and optimum process time. The PA chip is designed on a 0.25 µm GaN technology process and occupies a 1.515 mm2 area. At a 28 V supply, the gain and output power of the PA reaches 15 dB and 29 dBm respectively, and the wideband matching transformer reaches 47.6% bandwidth. To the best of our knowledge, the distributed model for coplanar asymmetry transformer and transformer-based X-band MMIC PA on GaN process in this work is the first case among the reported papers