小麦与白粉病菌相互作用的钙调素定位

本文对白粉病菌侵染后小麦表皮细胞内钙调素的动态变化过程进行了分析。结果表明,在正常情况下钙调素主要集中分布在泡内和胞外,在细胞衰老时进入解体的细胞器如细胞核等;接种白粉病菌后,感病细胞内的钙调素含量降低;但随着细胞的衰老钙调素含量又逐渐增加。钙调素逐渐穿过吸器外膜进入吸器外基质和退化的吸器内部。病原菌侵染后,抗病细胞中的钙调素迅速增加,并随着细胞的死亡散布在这个细胞中,上述结果说明,适当的钙离子浓度梯度是白粉病菌吸器发育和行使其功能的重要条件。     

小麦叶肉细胞与白粉病菌相互作用的细胞学机制

利用抑制小麦细胞基因表达的方法，分析了白粉病菌与小麦表皮细胞和叶肉细胞与病原菌的相互作用。结果发现，50μg/ml的α-amanitin可有效抑制基因的表达，植物防卫反应强度大幅度降低，细胞死亡延迟。但白粉病菌侵染表皮细胞的能力下降，说明白粉病菌侵染后，寄主细胞代谢状态的改变；而且在任何情况下，白粉病菌在叶肉细胞表面只能长出初生茅管，却不能形成附着胞。以上结果说明，叶肉细胞中存在着直接对白粉病菌有抑制作用的物质成分。细胞化学分析说明抑制物有可能是酚类化合物。     

辣椒疫霉菌在寄主体内菌丝发育的形态特征

本文利用透射电镜超薄切片技术了辣椒疫霉菌在寄主体内菌丝发育的形态特征。发现在被侵染的辣椒地上茎皮层组织中，菌丝既可细胞间生，也可细胞内生；细胞间生的菌丝不仅能以胞壁内陷或出芽方式裂繁殖，而且能以入侵栓方式穿入和穿过寄主细胞壁，并在寄主的胞壁和质膜间迅速膨大起来，但这个膨大的部分并非吸器，而是在穿壁处分割裂殖为内外两个菌丝细胞，同时被穿孔处的寄主细胞壁又自行弥合，修复完整。在菌丝胞壁内陷或入侵栓穿壁     

小麦白粉菌初侵染行为SEM研究

小麦白粉菌初侵染行为ＳＥＭ研究胡东维，李振歧，康振生（西北农业大学，陕西杨陵７１２１００）在禾白粉菌（Ｅｒｙｓｉｐｈｅｇｒａｍｉｎｉｓ）的初侵染过程中，寄主细胞产生一系列抗性反应从而把病原菌阻止在各个不同的发育阶段￣［１］。在超微结构上表现为同一品种...     

番茄斑萎病毒侵染引起寄主细胞的质壁分离

植物细胞在缺乏水份时．可引起原生质体收缩，导致质壁分离．是植物细胞逆境生理反应的特有现象在对番茄斑萎病毒（TSWV）浸染的寄主植物大量的细胞病理观察中，发观在葫芦科和茄科寄主中，有的病毒株系与寄主组合出现普通的质壁分离现象，在以往有关TSWV侵染寄主的细胞病理研究中未见报道。     

植物病毒感染寄主叶绿体的形态结构变化

植物病毒侵染系统寄主后产生显著的花叶症状 ,细胞内叶绿体结构和功能遭到破坏。在褪绿部位叶绿体发育不良 ,基粒类囊体垛叠差 ,体积变小、数量减少 ,有的发生团聚或接合 ,成熟叶绿体往往肿胀、片层松散 ,甚至整体瓦解。现已了解烟草花叶病毒 TMV、黄瓜花叶病毒 CMV、马铃薯 Y病毒 PVY的外壳蛋白 CP存在于被侵染的寄主细胞叶绿体中 ,特异性结合在类囊体膜的光系统 上 ,阻止了电子在传递链中的传递 ,推测电子传递链中断导致氧原子积累 ,降解叶绿体 ,是导致花叶症状的决定性因素。我们在植物病毒的细胞病理学研究中 ,对芜菁花叶病毒 Tu…     

水稻矮缩病毒云南、浙江分离株侵染水稻植株的细胞病理比较研究

为探讨水稻矮缩病毒（RDV）不同分离株侵染寄主植物的细胞病理学变化,验证RDV部分基因差异是否引起致病性差异,本文应用超薄切片电镜技术比较观察RDV云南分离株和浙江分离株侵染水稻的细胞病理.结果显示,RDV云南分离株侵染的水稻叶片中充满病毒粒体的细胞呈条带状分布,呈现出明显的侵染中心.在充满病毒粒体的细胞周围,相邻细胞不同程度地病变,叶绿体膜系统消失,部分叶绿体中含有病毒颗粒,线粒体残体及细胞质中有分散或聚集的病毒粒体,细胞核中未见病毒粒体;离侵染中心较远的细胞中亚细胞结构较完整.RDV浙江分离株侵染的水稻叶片中部分细胞充满病毒粒体,无明显的条带状分布,其他细胞病理特征与RDV云南分离株侵染的水稻叶片相似.这些结果表明,RDV不同分离株侵染寄主植株的细胞病理特征无显著差异,对其致病性的差异需进一步研究.     

百合病毒病原的检测诊断

应用电镜和ELISA检测查明浙江丽水和杭州栽培的百合受到黄瓜花叶病毒(CMV)及多种线状病毒侵染。寄主反应测定显示侵染百合的植物病毒寄主范围都很窄,不能通过汁液摩擦接种侵染昆诺藜、苋色藜、普通烟、心叶烟等6科12种指示植物。在64个ELISA检测样品中有26个受到CMV侵染,侵染率达40．6％;在75个负染色检测样品中有58个观察到线状病毒,侵染率达77．3％;在40个被线状病毒侵染的样品中有27个观察到细胞质风轮状内舍体,表明受到马铃薯Y病毒属成员的侵染,侵染率达67．5％。从不同线状病毒粒子形态及所引起的细胞病理变化来看,可能分属于马铃薯Y病毒属、麝香石竹潜隐病毒属和马铃薯X病毒属。     

单活塞线性压缩机用动力吸振器理论分析与Matlab仿真

单活塞线性斯特林制冷机由于其降温速度快、质量小和可靠性高等特点,目前正广泛用于红外探测器中,但是由于压缩机运行时产生的振动会严重影响探测器成像质量,所以在振动抑制方面动力吸振器的使用成为单活塞线性压缩机的最佳减振方式。基于此,本文首先论述了动力吸振器在单活塞线性压缩机减振方面的作用,并举例介绍了当前单活塞线性压缩机用动力吸振器的基本结构。为了不失理论分析的一般性,在动力吸振器与压缩机振动模型的理论计算中引入了几个重要的无量纲参数。最后在此基础上,利用Matlab软件对动力吸振器与压缩机模型进行振动幅频特性仿真。     

植物膜筏微区参与病原菌的防御反应

膜筏微区(membrane microdomains)是细胞质膜上富含固醇类和鞘脂类的高度动态的微结构域.膜筏微区及其动力学特性在植物的先天免疫反应中具有十分重要的作用.本文简要介绍了膜筏微区的概念及其功能,并着重总结了膜筏微区蛋白参与病原菌防御反应的研究进展,为阐明病原菌与宿主细胞的相互作用机制和病原菌侵染的防治提供了新思路.     

外源信号物质对肉苁蓉种子萌发体的影响研究

肉苁蓉（Cistanche deserticola Y.C.Ma）是沙生根寄生植物。采用激光扫描共聚焦显微镜（LSCM）,对种子经外源信号物质氟草敏（Norflurazon）、2,6-二甲氧基对苯醌（DMBQ）处理后萌发产生的类胚根状体、初生吸器的细胞形态;Ca2＋浓度、囊泡运输的变化情况进行了观察研究。结果表明,肉苁蓉种子萌发产生的类胚根状体顶部的细胞为多面体,细胞小,排列紧密,内含物较多,中部大多为长方形薄壁细胞,内含物少;经DMBQ处理后类胚根状体细胞的钙离子浓度升高,囊泡运输加强。研究结果为揭示外源信号物质对肉苁蓉寄生影响提供了理论依据。     

大豆豆荚与叶片的生理生化及超微结构的关系

本研究运用宏观数据分析、生理指标测定、透射电镜技术,对东农42和东农163两个品种的大豆豆荚进行了研究,发现大豆豆荚发育过程中细胞结构的变化引起了其性质和功能的变化.在豆荚发育的初期,细胞器发育还不完整,细胞核、叶绿体排列紧密,细胞核核质均匀,叶绿体的基粒片层初步形成.随着豆荚进一步发育,其叶绿体充分发育,叶绿体中积累的光合产物增多,光合细胞的活力增强.当大豆豆荚发育成熟时,其液泡较成熟前更大,细胞器被挤到边缘,叶绿体的基粒片层完善,结构清晰.     

中晚期鼻咽癌同步放化疗临床疗效观察

目的：观察同步放化疗治疗中晚期鼻咽癌的临床疗效。方法：我科于2001年至2004年收治的中晚期鼻咽癌83例,放射治疗方案为双侧面颈联合常规分割到36Gy至40Gy后避脊髓,鼻咽部缩野光子线照射至DT70Gy。颈部淋巴结行常规分割放疗后局部加量至66Gy至70Gy。同步化疗采用PF方案,放疗的前、中、后期各行1周期化疗,间隔时间为21天。观察同步放化疗疗效及各种毒副反应。结果：原发灶1个月、6个月、12个月的完全缓解率为88．0％、90．4％、94．0％,颈部淋巴结完全缓解率分别为92．1％、94．7％、98．7％,1年、3年、5年总生存率为91．5％、79．6％、61．3％。毒副反应患者可耐受。早期反应主要为骨髓抑制、口于和口腔黏膜炎;晚期反应主要为张口困难和颈部纤维化。结论：同步放化疗临床疗效好,毒副反应经有效的对症支持治疗和护理后患者可耐受,有较高的临床推广应用价值。     

Molecular orientation anisotropy and hole transport properties of diluted semiconducting films of poly(p-phenylenevinylene) derivative

The electrical and optical properties of certain semiconducting polymers are improved in blend films with inert host materials. The improvements have been attributed to the dilution effect of electron traps and interchain species in semiconductor materials. In this paper, we report on anisotropy in the blend films of poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and its strong dependence on an inert host material, such as polystyrene (PS) or polyvinylcarbazole (PVK). We found that the orientation of the MEH-PPV backbone in the blend film changed from horizontal to random on dilution with PS. Moreover, the in-plane hole conductivity was enhanced in the MEH-PPV:PVK blend film, although the out-of-plane conductivity reduced owing to excessive dilution. Mott–Schottky analysis of the capacitance–voltage characteristics revealed opposite trends for dilution with PS and PVK; i.e., PS increased the accumulated charge density in the bulk of the blend film, whereas PVK reduced it. These results demonstrate that isotropy was induced in the PS blend films, whereas anisotropy was induced in the PVK blend films. Anisotropy is an important factor for understanding the hole transport characteristics in the diluted films.     

草甘膦对大豆超微结构及光合指标影响的研究

利用透射电镜和扫描电镜,研究转基因抗草甘膦大豆和非抗草甘膦大豆东农42喷施草甘膦后大豆光合器官叶片的超微结构变化,并结合叶绿素含量、光合速率的测定,对比分析了抗草甘膦大豆和东农42在结构及生理功能上对草甘膦的表现及结构与功能变化的关系.研究结果表明抗草甘膦大豆对草甘膦的胁迫可以看作是一种适应.它首先经过一个损伤期,然后进入修复期,最终到基本恢复,表现出对草甘膦的抗性.而东农42的光合系统及光合功能则被草甘膦所彻底破坏.本文对其原因进行探究,以期为转基因作物育种尤其是超微结构方面的研究及草甘膦作用机理的研究有一定帮助.     

Langevin and Trap‐Assisted Recombination in Phosphorescent Organic Light Emitting Diodes

Bimolecular and trap‐assisted recombination mechanisms are investigated in small molecule‐based phosphorescent organic light emitting diodes (PhOLEDs) using the current?voltage?luminance characteristics in the diffusion current region, along with transient electroluminescence and capacitance measurements. Two different PhOLEDs, one with a single host, 4,4′‐Bis(carbazol‐9‐yl)biphenyl, and the other with an exciplex‐forming co‐host, are studied. Trap‐assisted recombination with a large number of trapped charges is dominant in the PhOLED with the single host because of the large energy gap between the host and the dopant state. In contrast, bimolecular Langevin recombination is dominant in the PhOLED with the exciplex forming co‐host, where a phosphorescent dye is doped in the co‐host. As a result, the accumulated charge density is lower in the co‐host system than in the single host emission layer, leading to high efficiency that approaches the theoretical limit, with an extremely low efficiency roll‐off.     

Operability diagram of drop formation and its response to temperature variation in a piezoelectric inkjet nozzle

The present study has focused on the operability diagram of drop formation and its response to temperature variation in an inkjet nozzle driven by a piezoelectric actuator. As an operating fluid, ethylene glycol was used, and square wave pulses were applied to the nozzle in the present experiments. The operability diagram was constructed in driving voltage and pulse width space by changing the operating temperature from 30 °C to 50 °C. Four distinct types of drop response have been uncovered and are summarized in the operability diagram. The four types of response include single primary drop formation, drop formation with satellites, nozzle wetting without drop formation, and emission of a random spray. From the operability diagram, W-shaped regime of single primary drop was found, which was enlarged as temperature increased. Furthermore, the time scale of the W-shaped regime is closely related to the optimal pulse width and meniscus oscillation period of the present inkjet nozzle. In addition, it was found that by increasing the driving voltage and temperature, the size of single primary drop is increased due to the reduction in viscosity and contact angle of the operating liquid.     

DC field response of hot carriers under circular polarized intense microwave fields in semiconductors limited to two-dimension

Hot carrier dynamics under intense microwave fields is investigated theoretically for the case that the dominant scattering process is optical phonon emission, and the carrier motion limited to two-dimension is intrinsic. When the microwave amplitude is appropriately large, an accumulated distribution of carriers in momentum space appears. The system of this motion is found to cause various peculiar DC fields response, e.g. strong non-linearity, negative differential conductivity, and negative response, under realistic physical conditions [J. Phys. Soc. Jpn 68 (1995) 2994]. In the proper strength of microwave and DC electric fields, especially in the case of circular polarized microwave fields, the carrier motions are converged to some trajectories in momentum space [Proceeding of 25th International Conference on the Physics of Semiconductors, 2001]. Resultantly a new type of accumulated distribution of carriers in momentum space appears. This situation is a sort of population inversion of carriers and causes various phenomena including a negative differential conductivity and/or a negative response appeared in the drift velocity vs. DC field relation not found in the case of linear polarized microwave fields. The carrier motion restricted in two-dimensional band may be essential and effective for these properties.     

基于QR分解的强鲁棒性双彩色盲水印算法

提出了一种将彩色快速识别(QR)码作为水印嵌入彩色宿主图像的强鲁棒性盲水印算法。首先 对彩色宿主图像分通道进行离散小波 变换(DWT)和分块QR分解得到非重叠的酉矩阵,然后将QR码分通道置乱加密归一化后嵌入到 宿主图像对应通道 酉矩阵的系数差中。仿真实验结果表明,本算法在满足不可见性的同时具有较强的鲁棒性; 相比现有算法, 本算法不仅能够抵抗旋转和裁切攻击,在JPEG压缩和噪声滤波攻击方面的抵抗能力也有较 大提升;而且本算法属于盲水印技术,具有较大的实际应用价值。