Physical control of leafhoppers

In 2000, a severe outbreak of phytoplasma-caused disease in Limonium spp. flowers devastated the industry in Israel; insecticides were not able to knock down and kill leafhopper vectors before they could transmit the pathogen. Nonchoice laboratory studies were conducted to determine the effect of UV-absorbing plastics on the movement of leafhoppers toward light; UV-absorbing plastic significantly reduced leafhopper movement. In choice trials conducted in sunlight, significantly more leafhoppers moved into the cage covered with regular plastic as opposed to the cage covered with UV-absorbing plastic. Field studies were conducted to determine at what height leafhoppers enter 2.5-3-m high walk-in tunnels; the majority enter the tunnels low to the ground, up to 1 m. Finally, field studies were conduced to compare leafhopper population levels in walk-in tunnels covered with UV-absorbing plastic or screening, and with ventilation holes at different heights above the ground. Elevated ventilation holes and UV-absorbing tunnel covering significantly reduced Orosius orientalis entrance into tunnels. Ramifications of these finding for leafhopper control are discussed.     

孜然化学成分及其生物活性研究进展

本文综述了孜然在化学成分、医疗、食品、农业等方面的研究进展,着重阐述了其在杀虫、抑菌方面的研究概况,以期为孜然在植物源农药方面的研究和综合开发应用提供依据。     

淋巴囊肿病毒中国株TNFR类似物的原核表达与结构分析

肿瘤坏死因子受体(TNFR)是细胞因子受体家族中的一员,在大DNA病毒的免疫逃避中起着重要的作用。 淋巴囊肿病毒中国株(LCDV-C)是一种大DNA病毒,属于虹彩病毒科。参照已知虹彩病毒TNFR基因设计引物: P1,5′GGATCCAAAACTATGATTAAAATAAAGA 3′;P2:5′ATTACTCGAGAATGTTAAAAATTAAGCTT 3′。以LCDV-C基因组DNA为模板,PCR扩增得到一个834bp的DNA片段,并对该片段进行测序。构建原核表 达重组质粒后,在大肠杆菌DE3中诱导表达,其产物经SDS-PAGE电泳后,显示为45kDa的融合蛋白带。对测序 结果进行计算机辅助分析的结果显示,LCDV-C TNFR类似物是一个含278个氨基酸的多肽,具有典型的半胱氨 酸富集区功能结构域,与宿主牙鲆TNFRII氨基酸同源性为34％。     

血管内皮生长因子受体3在大鼠胚胎皮肤淋巴管和血管内皮的表达及意义

目的观察血管内皮生长因子受体3(vascular endothelial growth factor receptor-3, VEGFR-3)蛋白在大鼠第15d胚胎和第21d胚胎皮肤淋巴管和血管内皮的表达水平,探讨VEGFR-3在胚胎淋巴管和血管发生发育中的生物功能.方法应用免疫组织化学技术(SABC法)对大鼠第15d和第21d胚胎共61例皮肤样本进行抗鼠VEGFR-3免疫组织化学染色,观察VEGFR-3在皮肤淋巴管和血管内皮细胞的表达情况.结果大鼠胚胎皮肤淋巴管和血管内皮细胞均阳性表达VEGFR-3蛋白,VEGFR-3蛋白在大鼠胚胎第15d、胚胎第21d皮肤淋巴管内皮细胞的阳性表达率分别是38.71%(12/31)和73.33%(22/30),第21d胚胎皮肤淋巴管VEGFR-3蛋白的表达水平明显高于第15d胚胎皮肤淋巴管VEGFR-3蛋白的表达水平(P<0.01).VEGFR-3蛋白在大鼠胚胎第15d、胚胎第21d皮肤血管内皮细胞的阳性表达率分别是48.39%(15/31)和46.67%(14/30),第15d和第 21d胚胎皮肤血管VEGFR-3蛋白的表达水平之间无明显差异(P>0.05).结论随着大鼠胚胎的发育,VEGFR-3蛋白在皮肤淋巴管的表达水平表现为明显上升的趋势,提示VEGFR-3在淋巴管发生发育中的作用逐渐增强.     

纽蛋白在神经干细胞定向分化为神经元过程中的表达及其与辅肌动蛋白的关系

目的探讨纽蛋白(vinculin)在新生大鼠大脑皮层神经干细胞定向分化神经元过程中的表达变化及其与辅肌动蛋白(α-actinin)的关系.方法将神经干细胞分离、培养、分化及鉴定后,采用免疫组化技术对新生大鼠皮层神经干细胞向神经元定向分化过程中,纽蛋白的时空表达进行研究,并采用免疫荧光双标技术及共聚焦激光扫描显微术对神经元定向分化过程中,纽蛋白与辅肌动蛋白关系进行探讨,利用图像分析技术对不同时段分化的神经元中vinculin平均积分光密度进行定量测定.结果在神经干细胞定向分化为神经元的过程中,vinculin由核周淡染分布逐渐至在胞体与突起中密集均匀分布,随着突起伸展而不断地延伸.图像分析结果表示,随神经元的分化成熟,vinculin的表达量呈逐渐增加趋势.在共聚焦激光扫描显微镜下观察免疫荧光双标vinculin/α-actinin在分化早期胞体和突起内均有分布,可见核周和突起两者融合两蛋白共存.近成熟期,随突起生长,两蛋白渐伸入突起,直至末端共存.结论本研究揭示大脑皮质神经干细胞定向分化为神经元过程中,vinculin表达变化与神经元发育成熟呈正相关,并且vinculin与α-actinin共存.     

大脑皮质神经干细胞定向分化为神经元过程中Tau蛋白表达的研究

目的探讨Tau蛋白在新生大鼠大脑皮质神经干细胞定向分化为神经元过程中的表达及意义.方法采用细胞培养、免疫细胞化学方法(SABC法)观察及计算机图像分析技术测定Tau蛋白在神经干细胞定向分化为神经元过程中不同时段的表达情况.结果在神经干细胞定向分化为神经元的过程中,Tau蛋白由核周淡染分布渐至在胞体与突起中密集均匀分布,随着突起伸展而不断地延伸,并且Tau蛋白的表达量逐渐增加.结论新生大鼠大脑皮质神经干细胞定向分化为神经元过程中,Tau蛋白的时空表达与神经干细胞定向分化的神经元形态变化有一定的相关性并在此过程中发挥着重要的作用.     

大脑皮层神经干细胞定向分化为神经元过程中细胞骨架-α辅肌蛋白表达的研究

目的探讨α辅肌蛋白在新生大鼠大脑皮层神经干细胞定向分化神经元过程中的表达变化.方法采用细胞培养、免疫细胞化学方法(SABC法)、免疫电镜技术观察α辅肌蛋白在神经干细胞定向分化神经元过程中不同时段的表达变化.利用图像分析技术对不同时段分化的神经元中α辅肌蛋白平均积分光密度进行定量测定.结果在神经干细胞定向分化神经元过程中,α辅肌蛋白由核周淡染分布逐渐至在胞体与突起中密集均匀分布,随着突起伸展而不断地延伸.免疫电镜可见α辅肌蛋白呈高电子密度球形颗粒.图像分析结果表示,随神经元的分化成熟,α辅肌蛋白的表达量呈逐渐增加趋势.结论大脑皮质神经干细胞定向分化为神经元过程中,α辅肌蛋白表达变化与神经干细胞定向分化的神经元形态变化相关.     

普通小麦远缘杂交F1代表现型研究

小麦远缘杂交试验采用常规杂交方法,不进行胚培养,在自然条件下,实现了普通小麦与小黑麦(6X,AABBRR)、柱穗山羊草(2X,DD)、人工合成六倍体小麦(6X,AABBDD)、CIMMYT人工合成小麦(6X,AABBDD)的杂交.发现在F1代中,出现了2～7种植株表现型、7种性状分离现象;小麦颖壳颜色变化可能受多个加性基因控制;杂交F2代结实率较F1代有数倍或十余倍的增长.     

中国砖格孢子丝孢菌研究 VI. 梭格孢属一新种

从山东蒙山采到一丝孢真菌新种,即木生梭格孢 Dictyodesmium lignicola sp. Nov.。 新种具宽纺锤形、梭形的分生孢子,无喙,与榆梭格孢 Dictyodesmium ulmicola 的窄纺锤形分生孢子具喙不同;新种与近似种竹梭格孢 Dictyodesmium bambusicola 相比具较大的分生孢子。本属为中国首次报道。文中提供了新种的拉丁文和英文描述并附图。模式标本保存在山东农业大学植物病理学标本室(HSAUP)。     

Selected Natural Materials in History

1 Technology of natural materials Early man used conveniently shaped stones as tools. ＂Workshop＂ areas have been found with large numbers of stones, some showing signs of being worked. However, organic materials like wood will decay under normal wet conditions in the presence of oxygen, so we won＇t find the same sort of evidence for wooden tools. It is safe to assume that early man used sticks as probes and clubs, and maybe even for making some sort of nestlike protection against the elements and predators, since we see chimpanzees and other animals doing this sort of thing. So wood, and ahnost certainly other plant materials such as fibrous leaves, and bone and other materials gleaned from dead animals, would be used from the earliest times. We need to know this in order to establish the idea that Man can be expected to have a long history of the use and manipulation of natural materials. This needs skills in choosing materials for certain uses on the basis of their mechanical properties, whether those properties are to do with the ease of shaping the material or the effectiveness of that material in use. Occasionally the material was chosen simply because it was readily available. If we find that a particular material was always used for a certain job, it＇s reasonable to deduce that Man was exerting materials selection criteria through experience.