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为探索从水母毒素中获取抗植物病毒物质的应用前景,采用半叶枯斑法、整株法和漂浮叶圆片法,对白色霞水母Cyanea nozakii Kishinouye刺细胞毒素的抗烟草花叶病毒(Tobacco mosaic virus,TMV)活性进行了检测。结果表明,白色霞水母刺细胞毒素对TMV具有很强的直接钝化作用,枯斑抑制率随钝化时间的延长而增大。0.99 mg/m L毒素体外钝化TMV 30 min,枯斑抑制率达98.85%,将TMV与0.80 mg/m L毒素体外混合后立即接种,枯斑抑制率仍达89.57%;20~70℃之间,毒素对TMV的钝化作用随温度升高而降低,但又表现出一定的高温耐受性,70℃下处理30min,1.33 mg/m L毒素对枯斑的抑制率为61.73%。毒素对病毒初侵染有一定的预防作用,并可抑制TMV的增殖;1.93 mg/m L毒素处理接种TMV的叶圆片2 d后,对TMV的增殖抑制率为49.41%;但该毒素对TMV所致病害的治疗效果不明显。该毒素还具有较强的蛋白水解酶活性,可能与其抗TMV活性相关。表明白色霞水母刺细胞毒素抗TMV作用明显,其抗植物病毒活性值得深入研究。 相似文献
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The aptitude of leafcutter bees to pollinate male sterile soybean plants (ms2 gene) in caged plots was evaluated in four experiments from both quantitative and qualitative points of view. The m.s. plant seed set was satisfactory: on average, it represented 60% of the male fertile isogenic seed set (with a range between 44 and 69%). The lower yield of m.s. plants was linked with a smaller number of fertile reproductive nodes. The efficient pollen flow was observed over the flowering period with both morphological and electrophoretic markers. Insect behaviour was not influenced by flower colour. Differences between flowering duration of pollen donors appear to be the major factor inducing unbalanced populations. The interest of this technique as a tool for dynamic management of the genetic variation in populations or for hybrid seed production is discussed. 相似文献
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在德宏地区,对春砂仁产量的形成起主要作用的蜜蜂有彩带蜂、隧蜂、中华蜜蜂、熊蜂、小蜜蜂、排蜂。其中彩带蜂、熊蜂、排蜂的有效传粉率高,小蜜蜂、隧蜂、中华蜜蜂次之。它们的数量、分布受生态环境、气候条件、砂仁种植面积等的影响,呈动态变化。春砂仁的自然授粉由几种蜜蜂共同进行,蜂多,传粉机率则高。全天蜂次与采花次,采集高峰时间每小时平均蜂次与传粉率,均呈极显著正相关。应用直线回归方程,可推算春砂仁花期是否具备足够传粉动力。观察结果表明,传粉率达90%以上的指标,是每平方米面积内当天开花50~70朵,采集高峰时间每小时出现钻花采集的蜜蜂20~30次。云南野生中华蜜蜂适应性强,生态类型多,定向筛选、繁育传粉效果好的蜂群,则可望解决初花期或缺少传粉昆虫地区的春砂仁授粉问题。 相似文献
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Johnson GS Turrentine MA Tomlinson JL 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1985,14(2):11-18
A rapid, qualitative blood test was developed to identify potential bleeders among dogs that are von Willebrand's disease suspects. The test, based on venom coagglutinin-induced agglutination of formalin-fixed washed platelets, was compared to the more lengthy electroimmunoassay for factor VIII-related antigen. The 2 tests were performed on plasma samples from 82 dogs, including 68 Doberman pinschers. The 39 plasma samples that were found to be "clinically normal" by the new test had factor VIII-related antigen concentrations ranging from 32% to 192% of that in a pool of normal canine plasma samples. Plasma samples from the 43 dogs that tested as "potential bleeders" by the new test had factor VIII-related antigen concentrations from 4% to 38%. All 43 "potential bleeders" were Doberman pinschers. Shortly after being evaluated by the new test, 46 of the dogs underwent invasive diagnostic, therapeutic, or cosmetic procedures. Excessive hemorrhage was encountered in 40% of the 25 dogs that tested as "potential bleeders. " In contrast, only 5% of the 21 dogs that tested as "clinically normal" exhibited abnormal bleeding. 相似文献
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AIM:To investigate the effect of platelet inhibitor from Agkistrodon halys venom (AHV-PI) on lipopolysaccharide (LPS) induced human umbilical vein endothelial cells (HUVECs) injury in vitro, and to explore its mechanism. METHODS:Cultured HUVECs were induced inflammatory injury by LPS (1 mg/L). The experiment was divided into blank control group, LPS group, AHV-PI group and AHV-PI+LPS group. The viability of HUVECs was measured by MTT assay. The morphological changes of HUVECs were observed under inverted microscope. The optimum concentration of AHV-PI at 5 mg/L was selected. Flow cytometry was used to detect apoptosis of HUVECs. Immunohistochemical method was used to observe the expression of tissue type plasminogen activator (t-PA) and plasminogen activator indhibitor-1 (PAI-1) of HUVECs. ELISA was used to detect the concentrations of intercellular adhesion molecule-1 (ICAM-1) and tissue factor (TF) in the supernatant. The activation and translocation of NF-κB subunit p65 were observed by immunofluorescence staining. RESULTS:The HUVECs were spindle shaped, the ratio of length to width was increased, the cells were fibroblast-like, and granular substance appeared in the cytoplasm in LPS group. The viability and morphological changes of HUVECs were not significantly affected as treated with AHV-PI at concentration of 0~5 mg/L, but the viability of HUVECs induced by LPS was inhibited and the morphological changes were alleviated. Compared with the blank control group, the levels of TF and ICAM-1 in the supernatant increased, and the expression of t-PA and PAI-1 in the HUVECs was decreased in LPS group. Compared with the LPS group, the contents of TF and ICAM-1 in the supernatant were significantly decreased, the expression of t-PA and PAI-1 in the HUVECs was increased and the expression of nucleus NF-κB p65 was decreased in AHV-PI+LPS group (P<0.05). CONCLUSION:AHV-PI reduces HUVECs damage. The protective mechanism is related to the inhibition of cytokine secretion and NF-κB activation. 相似文献
110.