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21.
本文运用Shannon—Wiener物种多样性指数、Simpson生态优势度指标以及边缘效应强度指数,对缙云山亚热带森林群落林窗的边缘效应现象进行了初步研究。29个林窗样地不同部位上述指标的测定表明用物种多样性指数拟合边缘效应测度通式,缙云山亚热带森林群落林窗的边缘效应强度值为1—3左右;而用生态优势度值拟合边缘效应强度测式,则上述边缘效应强度值为0.1一1.2左右。研究表明林窗边缘区由于边缘效应的作用有增大物种多样性的趋势。而林窗面积、所处坡向以及林窗所在的森林群落类型,都对处于不同发育阶段的林窗的边缘效应强度具有影响。在此基础上,本文对林窗边缘效应强度的变化规律、效应性质、测定意义以及对森林营造和优化管理上的作用进行了一定探讨。 相似文献
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Xiaohe Li Xiaoyang Ma Yang Miao Jianwei Zhang Buri Xi Wenqi Li Qianyi Zhang Li Chen Yue Yang Hongli Li Luqing Wei Honggang Zhou Cheng Yang 《Journal of cellular and molecular medicine》2023,27(3):422-434
Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease that seriously threatens the health of patients. The pathogenesis of IPF is still unclear, and there is a lack of effective therapeutic drugs. Myofibroblasts are the main effector cells of IPF, leading to excessive deposition of extracellular matrix (ECM) and promoting the progression of fibrosis. Inhibiting the excessive activation and relieving autophagy blockage of myofibroblasts is the key to treat IPF. PI3K/Akt/mTOR pathway plays a key regulatory role in promoting fibroblast activation and autophagy inhibition in lung fibrosis. Duvelisib is a PI3K inhibitor that can simultaneously inhibit the activities of PI3K-δ and PI3K-γ, and is mainly used for the treatment of relapsed/refractory chronic lymphocytic leukaemia (CLL) and small lymphocytic lymphoma tumour (SLL). In this study, we aimed to examine the effects of Duvelisib on pulmonary fibrosis. We used a mouse model of bleomycin-induced pulmonary fibrosis to evaluate the effects of Duvelisib on pulmonary fibrosis in vivo and further explored the potential pharmacological mechanisms of Duvelisib in lung fibroblasts in vitro. The in vivo experiments showed that Duvelisib significantly alleviated bleomycin-induced collagen deposition and improved pulmonary function. In vitro and in vivo pharmacological experiments showed that Duvelisib dose-dependently suppressed lung fibroblast activation and improved autophagy inhibition by inhibiting the phosphorylation of PI3K, Akt and mTOR. Our results indicate that Duvelisib can alleviate the severity of pulmonary fibrosis and provide potential drugs for the treatment of pulmonary fibrosis. 相似文献
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Ying-Ying Li Xi Chen Jin-Xian Yang Qiang Chen Tie-Ying Song Jun-Qing Ge 《Journal of fish biology》2023,102(1):141-154
Eels are important aquaculture species for which an increasing number of reference genes are being identified and applied. In this study, five housekeeping genes [RPL7 (ribosomal protein L7), 18 S (18 S ribosomal RNA), EF1A (elongation factor 1α), ACTB (β-actin) and GAPDH (glyceraldehyde-3-phosphate dehydrogenase)] were chosen to evaluate their reliability as reference genes for quantitative real-time PCR (qPCR) for the study of Anguilla anguilla. The expression of the selected genes in different eel tissues was determined using qPCR at different growth stages or upon challenge by Anguillid herpesvirus (AngHV), and the expression levels of these genes were then compared and evaluated using the geNorm and NormFinder algorithms. Then, RefFinder was used to comprehensively rank the examined housekeeping genes. Interestingly, the expression of the evaluated housekeeping genes exhibited tissue-dependent and treatment-dependent variations. In different growth periods A. anguilla tissues, the most stable genes were the following: ACTB in mucus; 18 S in skin and kidney; RPL7 in muscle, gill, intestine and brain; EF1A in heart and liver; and GAPDH in spleen. In contrast, in AngHV-challenged A. anguilla tissues, the most stable genes were the following: 18 S in mucus; RPL7 in skin, gill, heart, spleen, kidney and intestine; EF1A in muscle and liver; and ACTB in brain. Further comparison analysis indicated that the expression of RPL7 and EF1A was stable in multiple A. anguilla tissues in different growth periods and in eels challenged by AngHV. Nonetheless, the expression level of GAPDH in eel tissues was lower, and it was unstable in several tissues. These results indicated that the selection of reference genes for qPCR analysis in A. anguilla should be made in accordance with experimental parameters, and both RPL7 and EF1A could be used as reference genes for qPCR study of A. anguilla at different growth stages or upon challenge by AngHV. The reference genes identified in this study could improve the accuracy of qPCR data and facilitate further studies aimed at understanding the biology of eels. 相似文献
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He Xi Jiang Yifan Chen Sumei Chen Fadi Chen Feng 《Journal of Plant Growth Regulation》2023,42(2):1144-1157
Journal of Plant Growth Regulation - Terpenoids are a class of structurally diverse natural products involved in various plant biological processes. Their primary function is believed to provide... 相似文献
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布氏四鼠在低温条件下的实验观察 总被引:1,自引:1,他引:0
实验在-20℃的低温下进行。结果表明。(1)单笼饲养鼠平均存活期为145.9±30.8h。其中幼鼠耐低温力最差。然后依次为老体组、亚成体组、成体组。除幼体外,雌鼠的抗寒能力稍高于雄体。(2)饲喂冷蒿组比饲喂其它6种牧草在低温下布氏田鼠的存活期显著延长.(3)聚集可明显增强对低温的耐受程度。(4)窝草可使巢内温度保持在5~8℃,窝巢内层的温度可达15~22℃。 相似文献
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囊萼紫草属与滇紫草属花粉形态比较研究 总被引:3,自引:1,他引:2
本文借助光学显微镜和扫描电镜研究了囊萼紫草属3种和滇紫草属12种植物的花粉形态。囊萼紫草属的花粉为哑铃形或茧形,中等大小,P/E比为1.6一1.67,三孔沟,内孔横长;具小刺状纹饰。滇紫草属的花粉为近长球形或近卵球形,P/E为l—1.23;三孔沟或三合沟孔,内孔一般纵长,具皱波状纹饰,在皱波上具密集的小瘤或微颗粒。从花粉形态的角度,本文支持把囊萼紫草属从滇紫草属(广义)中分离出来的观点。值得注意的是,在滇紫草属的花粉中首次观察到了一种比较少见且特化的花粉即单极三合沟孔的花粉。 相似文献