228 research outputs found

    Plasminogen deficiency causes reduced angiogenesis and behavioral recovery after stroke in mice

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    Plasminogen is involved in the process of angiogenesis; however, the underlying mechanism is unclear. Here, we investigated the potential contribution of plasmin/plasminogen in mediating angiogenesis and thereby contributing to functional recovery post-stroke. Wild-type plasminogen naive (Plg(+/+)) mice and plasminogen knockout (Plg(-/-)) mice were subjected to unilateral permanent middle cerebral artery occlusion (MCAo). Blood vessels were labeled with FITC-dextran. Functional outcomes, and cerebral vessel density were compared between Plg(+/+) and Plg(-/-) mice at different time points after stroke. We found that Plg(-/-) mice exhibited significantly reduced functional recovery, associated with significantly decreased vessel density in the peri-infarct area in the ipsilesional cortex compared with Plg(+/+) mice. In vitro, cerebral endothelial cells harvested from Plg(-/-) mice exhibited significantly reduced angiogenesis assessed using tube formation assay, and migration, as evaluated using Scratch assays, compared to endothelial cells harvested from Plg(+/+) mice. In addition, using Western blots, expression of thrombospondin (TSP)-1 and TSP-2 were increased after MCAo in the Plg(-/-) group compared to Plg(+/+) mice, especially in the ipsilesional side of brain. Taken together, our data suggest that plasmin/plasminogen down-regulates the expression level of TSP-1 and TSP-2, and thereby promotes angiogenesis in the peri-ischemic brain tissue, which contributes to functional recovery after ischemic stroke

    Physiological response of natural C-taklimakanensis BRPan et GMShen to unconfined groundwater in the hinterland of the Taklimakan Desert

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    Calligonum. taklimakanensis B.R.Pan et G.M.Shen is an indigenous species that grows in the Taklimakan Desert. This study shows the relationship between C. taklimakanensis B.R.Pan et G.M.Shen and water conditions in the hinterland of the desert. The results show that: (1) Depth of water table is an important factor that affects water potential (Psi(p), Psi(A)), osmotic potential (Psi(sat), Psi(tlp)), relative water content (RWCtlp, ROWCtlp), and transpiration rate. (2) The degree of mineralization has a significant impact on the water potential of plants. A high degree of mineralization can strongly reduce plant productivity. (3) C. taklimakanensis B.R.Pan et G.M.Shen reduces the temperature of assimilation sticks through a high transpiration rate and maintains relatively high water content to adapt to drought and hot weather conditions in the hinterland of the desert. In addition, C. taklimakanensis B.R.Pan et G.M.Shen adapts to the water status in the desert through self-regulation or even sacrificing productivity

    A State of the Art Review on the Wellbore Blockage of Condensate Gas Wells: Towards Understanding the Blockage Type, Mechanism, and Treatment

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    AbstractWith the development of high-pressure and high-temperature condensate gas wells, the wellbore blockage problems have become increasingly serious. Hence, selecting appropriate treatment technology plays a crucial role in solving the wellbore blockage problems. This study presents a comprehensive literature review on understanding the blockage type, mechanism, and treatment of the high-temperature and high-pressure condensate gas wells. The causes, endangerments, mechanisms, influences, and preventive technologies of the 4 wellbore blockage types are presented. The significant aspects of the treatment technology, such as the principle, type, advantage and disadvantage, adaptability, limitation, and future research direction of the treatment technologies, are thoroughly discussed. The breakthrough solid autogenetic heat treatment technology has been selected to remove hydrate blockage. The present review highlights the current state in the industry, future position, and strategies for the researchers to follow. Finally, the advantages and disadvantages and future research directions of specific treatment technology are presented on the removing effect, cost, and environmental aspects
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