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排序方式: 共有260条查询结果,搜索用时 265 毫秒
71.
几种野生植物提取物抑菌作用研究 总被引:18,自引:0,他引:18
本文以乙醇为溶剂,分别提取了瓦松、泽漆及一组中草药配方的有效成分;室内测定了三种提取液对5种植物病原菌(棉花枯萎病菌Fusarium oxysporum f.sp.vasinfectum;小麦赤霉病菌Fusarium graminearum Schw;西瓜枯萎病菌Fusarium oxysporum f.sp.niveum;仙人掌软腐病菌Erwinia chrysanthemi pv.chrysanthemi;魔芋软腐病菌Erwiniacarotovora pv.carotovora)的抑菌作用.结果表明:三种提取物对镰刀菌均有不同程度的抑制作用,且三种提取物的抑菌效果差异显著,其中瓦松的抑菌效果最强.当在50 mL培养基中加入5mL不同提取液时,瓦松对不同镰刀菌的相对抑制率为91.39%~100%;中草药配方提取液对不同镰刀菌的相对抑制率分别为41.11%~85.37%;而泽漆提取液对镰刀菌的相对抑制率仅为12.86%~21.23%;当在50 mL培养基中加入提取液体积降低为2 mL、1 mL、0.5mL时,三种提取液对三种镰刀菌的抑制效果骤然下降,但下降的梯度不一.对大白菜软腐病菌与魔芋软腐病菌而言也是瓦松的抑菌效果最强,中草药配方次之,泽漆的抑制效果最差. 相似文献
72.
Galinsona parviflora (Asteraceae) is a wide-spread annual weed that is invasive,colonizing new ground where it is able to persist.We studied the bio-mass structure of the G.Parviflora population at the module level by using the methods of field plot invest-igation and weighing at 10 sample plots.Modular bio-mass was calculated and used for analysis of relation-ships between various modules.The results show that there was a positive correlation between plant height and modular biomass,between stem biomass and root biomass,stem biomass and capitulum biomass,above-ground biomass and underground biomass,and lastly,stem biomass and leaf biomass.The preferred model which measured all the relationships was a power func-tion model with absolute coefficients(R2) ranging from 0.6303 to 0.9782. 相似文献
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Weijun Gong Shuyan Qie Peiling Huang Jianing Xi 《Journal of cellular biochemistry》2019,120(1):836-847
Long noncoding RNAs (lncRNAs) have been reported to be involved in several neurological pathogenesis conditions including cerebral ischemia. In the current study, the functions of lncRNA EFNA3 on hypoxia-injured rat adrenal pheochromocytoma (PC-12) cells and the underlying molecular mechanism were studied. The expression of lncRNA EFNA3 was silenced by short hairpin RNA transfection, after which the cells were subjected with hypoxia. Cell viability, migration, invasion, and apoptosis were, respectively, determined by trypan blue staining, Transwell assay, annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double-staining, and Western blot analysis. The cross regulation between lncRNA EFNA3 and miR-101a, as well as between miR-101a and Rho associated coiled-coil containing protein kinase 2 (ROCK2) were detected by performing quantitative real-time polymerase chain reaction, RNA pull-down, RNA immunoprecipitation, luciferase activity assay, and Western blot analysis. Studies showed that lncRNA EFNA3 was highly expressed in response to hypoxia. Deletion of lncRNA EFNA3 significantly aggravated hypoxia-induced injury in PC-12 cells, as the impairment of cell viability, migration, and invasion, and the inducement of apoptosis. LncRNA EFNA3 worked as a sponging molecule for miR-101a and miR-101a suppression-protected PC-12 cells against hypoxia-induced injury even when lncRNA EFNA3 was silenced. ROCK2 was a target gene of miR-101a. ROCK2 overexpression exhibited neuroprotective activities. Besides, ROCK2 overexpression activated Wnt/β-catenin pathway whereas it deactivated JAK/STAT pathway upon hypoxia. Our study suggests that deletion of lncRNA EFNA3 aggravates hypoxia-induced injury in PC-12 cells by upregulating miR-101a, which further targets ROCK2. 相似文献
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Shuyan Shao Jian Liu Giuseppe Portale Hong‐Hua Fang Graeme R. Blake Gert H. ten Brink L. Jan Anton Koster Maria Antonietta Loi 《Liver Transplantation》2018,8(4)
The low power conversion efficiency (PCE) of tin‐based hybrid perovskite solar cells (HPSCs) is mainly attributed to the high background carrier density due to a high density of intrinsic defects such as Sn vacancies and oxidized species (Sn4+) that characterize Sn‐based HPSCs. Herein, this study reports on the successful reduction of the background carrier density by more than one order of magnitude by depositing near‐single‐crystalline formamidinium tin iodide (FASnI3) films with the orthorhombic a‐axis in the out‐of‐plane direction. Using these highly crystalline films, obtained by mixing a very small amount (0.08 m ) of layered (2D) Sn perovskite with 0.92 m (3D) FASnI3, for the first time a PCE as high as 9.0% in a planar p–i–n device structure is achieved. These devices display negligible hysteresis and light soaking, as they benefit from very low trap‐assisted recombination, low shunt losses, and more efficient charge collection. This represents a 50% improvement in PCE compared to the best reference cell based on a pure FASnI3 film using SnF2 as a reducing agent. Moreover, the 2D/3D‐based HPSCs show considerable improved stability due to the enhanced robustness of the perovskite film compared to the reference cell. 相似文献
79.
Water Splitting: Atomically Thin Mesoporous In2O3–x/In2S3 Lateral Heterostructures Enabling Robust Broadband‐Light Photo‐Electrochemical Water Splitting (Adv. Energy Mater. 9/2018) 下载免费PDF全文
80.
Leaf‐Mosaic‐Inspired Vine‐Like Graphitic Carbon Nitride Showing High Light Absorption and Efficient Photocatalytic Hydrogen Evolution 下载免费PDF全文
Yi Zhang Lanlan Wu Xinyu Zhao Yingnan Zhao Huaqiao Tan Xia Zhao Yuanyuan Ma Zhao Zhao Shuyan Song Yonghui Wang Yangguang Li 《Liver Transplantation》2018,8(25)
Green plants use solar energy efficiently in nature. Simulating the exquisite structure of a natural photosynthesis system may open a new approach for the construction of desirable photocatalysts with high light harvesting efficiency and performance. Herein, inspired by the excellent light utilization of “leaf mosaic” in plants, a novel vine‐like g‐C3N4 (V‐CN) is synthesized for the first time by copolymerizing urea with dicyandiamide‐formaldehyde (DF) resin. The as‐prepared V‐CN exhibits ultrahigh photocatalytic hydrogen production of 13.6 mmol g?1 h?1 under visible light and an apparent quantum yield of 12.7% at 420 nm, which is ≈38 times higher than that of traditional g‐C3N4, representing one of the highest‐activity g‐C3N4‐based photocatalysts. This super photocatalytic performance is derived from the unique leaf mosaic structure of V‐CN, which effectively improves its light utilization and affords a larger specific surface area. In addition, the introduction of DF resin further optimizes the energy band of V‐CN, extends its light absorption, and improves its crystallinity and interfacial charge transport, resulting in high performance. It is an easy and green strategy for the preparation of broad‐spectrum, high‐performance g‐C3N4, which presents significant advancement for the design of other nanophotocatalysts by simulating the fine structure of natural photosynthesis. 相似文献