92 research outputs found

    Protective effects of Naringin in a rat model of spinal cord ischemia–reperfusion injury

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    Purpose: To evaluate the activity of naringin (NAR) in a rat model of spinal cord ischemic injury (SCII).Methods: Forty female rats were randomized into four groups: saline without  occlusion (control; group I), SCII (group II), 50 mg/kg NAR (group III), or 100 mg/kg NAR (group IV) for 7 days prior to SCI insult (pre-treatment). Neurological and locomotor functions, antioxidant activity, edema and inflammatory markers were determined.Results: Pre-treatment with NAR considerably lowered the incidence of spinal edema, lipid peroxidation products, and inflammatory markers (TNF-α, NF-p65, IL-1β, and IL-6). It also successfully reverted the antioxidative activity to near-normal levels and improved locomotor function by protecting spinal tissue from oxidative damage and inflammatory insults. NAR administration effectively downregulated the protein expression of TNF-α and NF-κB p65 subunit in spinal tissue, thus confirming its antiinflammatory activity.Conclusion: The results suggests that NAR exhibits neuroprotective effects by inhibiting free radical generation and downregulating inflammatory markers in an SCI rat model.Keywords: Naringin, Spinal cord injury, Locomotor function, Edema, Oxidative  stress, Inflammatio

    Association Analysis and Identification of ZmHKT1;5 Variation With Salt-Stress Tolerance

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    The high-affinity potassium transporter (HKT) genes are essential for plant salt stress tolerance. However, there were limited studies on HKTs in maize (Zea mays), and it is basically unknown whether natural sequence variations in these genes are associated with the phenotypic variability of salt tolerance. Here, the characterization of ZmHKT1;5 was reported. Under salt stress, ZmHKT1;5 expression increased strongly in salt-tolerant inbred lines, which accompanied a better-balanced Na+/K+ ratio and preferable plant growth. The association between sequence variations in ZmHKT1;5 and salt tolerance was evaluated in a diverse population comprising 54 maize varieties from different maize production regions of China. Two SNPs (A134G and A511G) in the coding region of ZmHKT1;5 were significantly associated with different salt tolerance levels in maize varieties. In addition, the favorable allele of ZmHKT1; 5 identified in salt tolerant maize varieties effectively endowed plant salt tolerance. Transgenic tobacco plants of overexpressing the favorable allele displayed enhanced tolerance to salt stress better than overexpressing the wild type ZmHKT1;5. Our research showed that ZmHKT1;5 expression could effectively enhance salt tolerance by maintaining an optimal Na+/K+ balance and increasing the antioxidant activity that keeps reactive oxygen species (ROS) at a low accumulation level. Especially, the two SNPs in ZmHKT1;5 might be related with new amino acid residues to confer salt tolerance in maize.Key Message: Two SNPs of ZmHKT1;5 related with salt tolerance were identified by association analysis. Overexpressing ZmHKT1;5 in tobaccos showed that the SNPs might enhance its ability to regulating Na+/K+ homeostasis

    The Formation and Evolution of Interorganisational Business Networks in Megaprojects: A Case Study of Chinese Skyscrapers

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    Megaprojects are implemented by different organisations, such as owners, consultants, and contractors. Gradually, these organisations and their connections can form business networks that influence both the market position of individual organisations and project performance. Previous research on large-scale projects mainly focused on static and homogeneous networks that were constructed by one individual project and/or carried out over one-off collaboration. However, this neglected the consideration of project network diversity, as well as repetitive, dynamic, cross-project coopetition relationship (i.e., collaboration and competition) and long-term business networks formed by key actors. Here, we chose Chinese skyscrapers over 300 meters that were built from 1996 to 2015 as typical megaproject cases and analysed the formation and evolution of megaproject business networks from the perspective of interorganisational coopetition. We identified the key actors involved and empirically studied their dynamic network positions over time. The main contributions of this study are threefold. First, we found that past collaboration experience has direct and dynamic impacts on the formation of megaproject business networks. Second, we identified key actors in the interorganisational business network and unveiled their dynamic positions with clear patterns. Third, we highlighted the temporal-spatial effect on the formation and development of business networks, alongside developments in the megaproject market. The findings of this study also provide practical applications for owners to choose collaboration partners and to build high-performance teams and for suppliers to enter and sustain the business in the megaprojects networks
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