14 research outputs found

    Effect of Soil Structure Interaction on Torsional Response of Structure Supported by Asymmetric Soil Foundation System

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    The torsional response of a structure supported by asymmetric foundation was investigated in this study. Several types of the asymmetric soil foundation system were employed to analyze the effect of soil structure interaction on torsional response of the superstructure. It can be concluded from the study that torsional response would be generated for a structure supported by asymmetric soil foundation system under horizontal seismic excitation, and the generated torsional response of the superstructure changed with the degree of the asymmetry of the foundation

    Effect of Deep Vertical Rotary Tillage on Soil Properties and Sugarcane Biomass in Rainfed Dry-Land Regions of Southern China

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    Conventional tillage (CT) is the main agricultural practice for rainfed sugarcane production in China. However, subsoil compaction formed by long-term CT is harmful to soil properties and crop yield. Deep vertical rotary tillage (DVRT) is a novel tillage practice, which can alleviate subsoil compaction and create a more favorable soil environment for crop growth. This study aims to compare the effects of DVRT and CT practices on soil properties and sugarcane characteristics. The results showed that DVRT reduced soil bulk density and increased soil porosity to some extent in the 0–40 cm soil profile. Soil water storage of DVRT was relatively higher compared with CT due to the combined effects of soil water holding capacity and vegetation water consumption. There was significantly higher final aboveground biomass, underground biomass, and plant height from DVRT compared to CT (p < 0.05), but there were no differences in final root length between tillage practices. Compared with CT, DVRT with one and two growth-years significantly increased aboveground biomass by 68.90% and 50.14%, respectively. Generally, the soil properties and sugarcane characteristics were not significantly different between DVRT with different growth years. DVRT is recommended as a tillage practice for sustainable agriculture in rainfed regions

    Astragalus polysaccharides and astragaloside IV alleviate inflammation in bovine mammary epithelial cells by regulating Wnt/β-catenin signaling pathway

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    The Wnt/β-catenin signaling regulates cell renewal and repair and is closely associated with inflammation. Astragalus polysaccharides (APS) and astragaloside IV (AS-IV), which are the main active substances extracted from Radix Astragali, protect cells by regulating Wnt signaling in cells, exerting antiinflammatory, antioxidant, and antistress effects. However, the mechanisms by which APS and AS-IV interact with Wnt signaling to achieve their therapeutic effects in bovine mammary epithelial cells (BMECs) are not understood. In this study, we used lipopolysaccharide (LPS)-stimulated BMECs as an in vitro model of inflammation to investigate the effects of APS and AS-IV on Wnt signaling in inflamed BMECs. Drug concentrations were screened using the CCK-8 method, the effect on protein expression was analyzed using immunoblotting, the effect on inflammatory factors using enzyme-linked immunosorbent assay, and the effect on oxidative factors using enzyme labeling and flow cytometry. LPS activated the expression of inflammatory and oxidative factors in cells and inhibited Wnt/β-catenin signaling. APS and AS-IV antagonized the inhibitory effect of LPS, protecting BMECs. They inhibited the expression of the IL-6, IL-8, and TNF-α inflammatory factors, and that of the MDA oxidative factor, and activated Wnt signaling in LPS-stimulated BMECs. Silencing of β-catenin abolished the protective effect of APS and AS-IV against LPS-stimulated BMECs. Thus, APS and AS-IV mediate protective effects in inflammatory BMECs model through activation of the Wnt signaling pathway. Wnt signaling pathway is one of the targets of the inhibitory effects of APS and AS-IV on inflammation

    Deposition of Photocatalytic TiO2 Coating by Modifying the Solidification Pathway in Plasma Spraying

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    The deposition of photocatalytic TiO2 coatings with plasma spraying is attractive for large-scale applications due to its low cost and simplicity, but it is still a challenge to obtain a TiO2 coating with high anatase content. The solidification pathway of inflight melted particles was investigated in the present paper, and TiO2 coatings with enhanced photocatalytic activity were obtained without a significant loss of the microhardness. The coating microstructure, phase composition, and crystallite size were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Photocatalytic performance was evaluated by decomposing an aqueous solution of methylene blue. Results showed that the anatase content in TiO2 coating was augmented to 19.9% from 4%, and the time constant of the activity was increased to 0.0046 h−1 from 0.0017 h−1

    Epidemiological investigation of non-albicans Candida species recovered from mycotic mastitis of cows in Yinchuan, Ningxia of China

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    Abstract Background Candida spp. is the vital pathogen involved in mycotic mastitis of cows. However the epidemiology and infection of Candida species in mycotic mastitis of cow in Ningxia province of China has not been explored. In the present study, the epidemiology, antimicrobial susceptibility and virulence-related genes of non-albicans Candida (NAC) species were investigated. Methods A total of 482 milk samples from cows with clinical mastitis in four herds of Yinchuan, Ningxia were collected and used for the isolation and identification of mastic pathogens by phenotypic and molecular characteristics, and matrix-assisted laser desorption ionization-time of flight mass spectrometry. The antimicrobial susceptibility to antifungal agents was also determined by a disk diffusion assay. The presence of virulence-related genes was determined by polymerase chain reaction (PCR). Results A total of 60 isolates from nine different Candida species were identified from 256 (60/256, 23.44%) milk samples. The most frequently identified species in cows with clinical mastitis groups were Candida krusei (n = 14) and Candida parapsilosis (n = 6). Others include Candida lipolytica, Candida lusitaniae, Cryptococcus neoformans. But no Candida albicans was identified in this study. Interestingly, All C. krusei isolates (14/14) were resistant to fluconazole, fluorocytosine, itraconazole and ketoconazole, 2 out of 14 C. krusei were resistant to amphotericin, and 8 out of the 14 were resistant to nystatin. Similarly, all six C. parapsilosis isolates were resistant to fluorocytosine, but susceptible to fluconazole, ketoconazole and nystatin; two of the six were resistant amphotericin and itraconazole. Molecularly, all of the C. parapsilosis isolates carried eight virulence-related genes, FKS1, FKS2, FKS3, SAP1, SAP2, CDR1, ERG11 and MDR1. All of the C. krusei isolates contained three virulence-related genes, ERG11, ABC2 and FKS1. Conclusion These data suggested that Candida species other than C. albicans played a pathogenic role in mycotic mastitis of cows in Yinchuan, Ningxia of China. The high incidence of drug-resistant genes in C. parapsilosis and C. krusei also highlighted a great concern in public and animal health in this region

    Effects of Total Alkaloids of Sophora alopecuroides on Biofilm Formation in Staphylococcus epidermidis

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    Staphylococcus epidermidis (S. epidermidis) is an opportunistic pathogen with low pathogenicity and a cause of the repeated outbreak of bovine mastitis in veterinary clinical settings. In this report, a biofilm model of S. epidermidis was generated and the minimal inhibitory concentration (MIC) and sub-MIC (SMIC) on bacterial cultures were assessed for the following agents: total alkaloids of Sophora alopecuroides (TASA), ciprofloxacin (CIP), and erythromycin (ERY). The formation and characteristic parameters of biofilm were analyzed in terms of XTT assay, silver staining, and confocal laser scanning microscope (CLSM). Results showed that a sub-MIC of TASA could inhibit 50% biofilm of bacterial activity, while 250-fold MIC of CIP and ERY MICs only inhibited 50% and 47% of biofilm formation, respectively. All three agents could inhibit the biofilm formation at an early stage, but TASA showed a better inhibitory effect on the late stage of biofilm thickening. A morphological analysis using CLSM further confirmed the destruction of biofilm by these agents. These results thus suggest that TASA has an inhibitory effect on biofilm formation of clinic S. epidermidis, which may be a potential agent warranted for further study on the treatment prevention of infection related to S. epidermidis in veterinary clinic

    The Influence of Anode Inner Contour on Atmospheric DC Plasma Spraying Process

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    In thermal plasma spraying process, anode nozzle is one of the most important components of plasma torch. Its inner contour controls the characteristics of plasma arc/jet, determining the motion and heating behaviors of the in-flight particles and hence influencing the coating quality. In this study, the effects of anode inner contour, standard cylindrical nozzle, and cone-shaped Laval nozzle with conical shape diverging exit (CSL nozzle) on the arc voltage, net power, thermal efficiency, plasma jet characteristics, in-flight particle behaviors, and coating properties have been systematically investigated under atmospheric plasma spraying conditions. The results show that the cylindrical nozzle has a higher arc voltage, net power, and thermal efficiency, as well as the higher plasma temperature and velocity at the torch exit, while the CSL nozzle has a higher measured temperature of plasma jet. The variation trends of the plasma jet characteristics for the two nozzles are comparable under various spraying parameters. The in-flight particle with smaller velocity of CSL nozzle has a higher measured temperature and melting fraction. As a result, the coating density and adhesive strength of CSL nozzle are lower than those of cylindrical nozzle, but the deposition efficiency is greatly improved
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