共查询到20条相似文献,搜索用时 15 毫秒
1.
用冷冻断裂法在扫描电镜下研究了洋葱(Allium cepa)根端分生组织细胞内部的三维结构。采用了两种固定方法。冷冻断裂前只用1%锇酸固定的材料容易在细胞质和核之间断开,而用卡诺固定液(无水乙醇:冰醋酸3:1)前固定,然后再用1%锇酸固定的材料容易使细胞核断裂。前一固定方法适于研究细胞质的内部结构(细胞骨架的纤维、线粒体、内质网等及其三维分布关系):后一固定方法适于研究核内结构(染色质、核仁、核基质纤维)的三维形象,特别是核仁纤维中心染色质的三维结构。 相似文献
3.
Summary Two different fixative procedures (immersion and perfusion) and four different fixative solutions were used in order to obtain the best preservation of the brush cells of the common bile duct of the rat. The results indicate that only perfusion fixation through the common bile duct is suitable, independent of the fixative solutions and their osmolarity.Numerous brush cells were seen in the proximal and distal regions of the common bile duct. In these locations, they could be implicated in a registration and/or regulation of intraluminal pressure variations. 相似文献
4.
5.
6.
Red deer antler was, together with stone, one of the most important raw materials for tool manufacture in prehistoric times. Both the physical characteristics of this material and the manufacturing technology of antler tools are examined. The use of experimental tests and analytical studies of the recovered antler finds allow us to propose, with a great degree of confidence, that the main use of antler axes during the Stone Age/Bronze Age was in woodworking. 相似文献
7.
8.
天南星属植物的花粉形态 总被引:1,自引:1,他引:1
利用扫描电镜对天南星科天南星属(Arisaema)8组25种植物的花粉进行研究(其中,12种前人未观察过,12种中11种为我国特有)。结果显示:本属花粉形态基本一致,即球形,无萌发孔,无覆盖层,具微刺,是一个非常自然的类群。但各个种在花粉粒大小,刺长,刺的形状,刺基部上径,刺的密度和刺间纹饰方面差别较大,可以作为区别种的依据。这进一步证实了前人的结论。花粉形态支持学者们关于天南星属是本科最进化的类群之一的观点。天南星属花粉可能由线花组从花粉大小适中、刺密度居中向大或小、密或疏的方向发展;刺间表面纹饰对探讨组间演化关系意义不大。Murata等对于花粉刺间具较密颗粒为曲序组特征的界定可疑;把A.yunnanense Buchet、A.bathycoleum Hand.-Mazt.和A.prazeri Hook.f.归入曲序组似乎不妥。A.consanguineum Schott和A.fraternum Schott的花粉形态没有支持李恒对这两个种的归并。 相似文献
9.
10.
以BTAM428(高抗)和ICS-12B(高感)及二者杂交的F2代为试材,对其形态及组织结构进行研究。结果表明:抗感品种形态及组织结构上均有差异。在抗蚜高粱品系的气孔数目多于感蚜品系;其下表皮的表皮蜡质比感蚜的致密;维管束的直径则小于感性的。 相似文献
11.
中国天南星科花粉形态的研究 总被引:5,自引:0,他引:5
利用扫描电镜对天南星科Araceae22属28种(除Arum maculatum产自德国外,其余均产自中国)及菖蒲科Acoraceae 1属2种植物的花粉形态进行了观察。结果显示天南星科花粉形态在科内变异很大。花粉粒形状从球形、近球形、椭球形到扁球形和橄榄形;萌发孔类型有散孔型、具薄壁区型、环沟型或无萌发孔;外壁纹饰为小穴状、网状、肋条状、条纹状、疣状、具刺或光滑。主要依据花粉形态方面的证据探讨了崖角藤属Rhaphidophora、麒麟叶属Epipremnam 、龟背竹属Monstera 3属的属间关系以及犁头尖属Typhonium属下分类中存在的一些问题。 相似文献
12.
粘虫性信息素分泌腺的超微结构 总被引:3,自引:0,他引:3
对粘虫Mythimna separata雌蛾性信息素分泌腺的位置及结构进行了光学显微镜、扫描电镜。透射电镜的观察,结果表明:粘虫性信息素分泌腺位于腹部末端第8-9节节间膜腹面。求偶时,伸出节间膜,为一白色的囊泡。腺体表面分布着饱满的锥状体。羽化后5天未交尾雌蛾,腺体细胞呈单层排列,中央细胞为柱状,细胞核为椭圆形。细胞与细胞间有明显的胞连接,细胞基底膜基褶较高,质膜上,分布着微绒毛,并与内表皮连接,内表皮之上含有多层几丁质,外角质层染色较深。细胞质中含有空泡,线粒体、脂质粒、糖原及粗面内质网。了解粘虫性信息素分泌腺的位置形态结构,对了解性信息素合成和释放的时辰节律,改进性信息素的提取、分离、鉴定是有意义的。 相似文献
13.
目的:研究高内皮微静脉周围网状细胞和网状纤维网的形态、密度、排列方式及其空间联系,探讨高内皮微静脉周围网状的组织构筑与功能。方法:用镀银染色光镜观察法和冻裂割断扫描电镜观察法观察健康、成熟Wistar大鼠肠系膜淋巴结内高内皮微静脉的基质网状结构。结果:高内皮微静脉周围基质结构主要由密集、交织的网状细胞和网状纤维组成,并在高内皮微静脉周围形成轮样结构。结论:高内皮微静脉周围网状纤维形成网状纤维网,并与淋巴迷路周围的淋巴迷路周围的网状纤维网相连,可能是淋巴细胞归巢的重要通路。 相似文献
14.
The leopard seal is a top-order predator in the Southern Ocean ecosystem and preys on a wide variety of vertebrate species
including seals and penguins. We assessed the use of hairs found in leopard seal scats to identify the species of pinniped
consumed. A reference collection of hairs was obtained from four potential leopard seal prey species including crabeater,
Weddell, Ross, and Southern elephant seals. Discrimination techniques applied to terrestrial mammals did not allow for identification
of the seal hairs. Instead, a 2-dimensional (2-D) and 6-dimensional (6-D) analysis technique utilising Mahalanobis distances
(D
2) was used. The smallest Mahalanobis distance together with the largest value of p(F) positively identified hairs from each species. The 6-D analysis was more accurate and applied to hairs found in the leopard
seal scats. The majority of prey species were identified as crabeater seals, which are a known prey item of the leopard seal. 相似文献
15.
16.
Summary The teleostean cerebellar cortex has been studied with respect to its cytoarchitectonic arrangement and intracortical neuronal circuits. Samples of fish cerebellum were fixed either by immersion or vascular perfusion in 5% glutaraldehyde solution and processed for light and scanning electron microscopy. The cerebellar cortex shows four distinct layers: granular; fibrous stratum; Purkinje cell; and molecular layers. In the granular layer, mossy and climbing fiber glomeruli were characterized. The mossy glomerular region appeared as polygonal, round or ovoid clews formed by the convergence of up to 17 dendritic profiles upon a thick mossy fiber branch. The en passant nature of mossy fiber-granule cell dendrite synaptic relationship was clearly appreciated. The climbing fibers showed tendril and glomerular collaterals. The latter form thin, elongated glomeruli. Remnants of a neuroglial envelope were observed in the mossy fiber glomeruli but are apparently absent from the climbing fiber glomeruli. The beaded-shape Golgi cell axonal ramifications were observed participating in the formation of both glomerular types. Velate protoplasmic astrocytes and oligodendrocytes were also identified. The fibrous stratum appeared to be formed by compact bundles of thick and thin myelinated axons, running horizontally beneath the Purkinje cell layer and apparently belonging to ascending climbing fibers and descending Purkinje cell axons. At the Purkinje cell layer a selective removal of Bergmann glial cells was observed allowing the visualization of the pericellular basket and the pinceaux. Climbing fiber stems and their tendril collaterals were seen on their way to the molecular layer ascending parallel to the Purkinje dendritic ramifications. Stellate neuron processes were found passing through the fan-like arborescence of Purkinje cell dendrites. 相似文献
17.
18.
目的建立白色念珠菌生物膜体外模型,为进一步研究白色念珠菌生物膜的耐药机制及干预提供基础。方法平板法培养白色念珠菌生物膜,利用扫描电镜、激光共聚焦显微镜和荧光显微镜等多种检测方法观察生物膜形成情况。结果白色念珠菌能够在玻片上形成典型的生物膜,通过荧光显微镜、扫描电镜和激光共聚焦显微镜下观察白色念珠菌随着时间增加逐渐增加,48 h形成初步生物膜,72 h结构更加复杂和成熟。ISA软件定量化分析显示,SYTO9/PI荧光探针标记的生物膜模型的区域孔径(AP)在24、48和72 h分别为0.95±0.06、0.89±0.01和0.83±0.01,平均扩散距离(ADD)分别为1.16±0.13、1.26±0.06和2.43±0.76,结构熵(TE)分别为4.87±0.34、5.18±0.35和5.47±0.16,两两比较,差异均有统计学意义(P0.05)。Im age-Pro P lus 6.0软件分析显示,生物膜内真菌死亡率分别为(34.71±2.72)%、(36.63±4.20)%和(47.41±2.53)%,与24 h及48 h相比,72 h真菌死亡率增加差异具有统计学意义(P0.05)。结论平板法能够较好地建立白色念珠菌生物膜体外模型,并可利用多种方式检测。 相似文献
19.
Summary Whole, critical-point dried cells of protonemata of the mossBryum tenuisetum have been examined in the high-voltage electron microscope at 1 MV. Fine cytoskeletal elements form a three-dimensional meshwork in the cytoplasm. This resembles, but has some differences from, the microtrabecular lattice seen in spread animal cells examined by the same technique. 相似文献
20.
Mathalaimuthu Baranitharan Saud Alarifi Saad Alkahtani Daoud Ali Kuppusamy Elumalai Jeganathan Pandiyan Kaliyamoorthy Krishnappa Mohan Rajeswary Marimuthu Govindarajan 《Saudi Journal of Biological Sciences》2021,28(1):148-156
Globally, the farmers are struggling with polyphagous insect pest, and it is the number one enemy of agri-products, which made plenty of economic deterioration. Spodoptera litura and Helicoverpa armigera are the agronomically important polyphagous pests. Most of the farmers are predominately dependent on synthetic chemical insecticides (SCIs) for battle against polyphagous pets. As a result, the broad spectrum usage of SCIs led a lot of detrimental outcomes only inconsequently the researchers search the former-friendly phyto-pesticidal approach. In the present investigation, leaf ethanol extract (LEE) and silver nanoparticles (AgNPs) of A. catechu (Ac) were subjected to various spectral (TLC, CC, UV, FTIR, XRD and SEM) analyses. Larval and pupal toxicity of A. catechu Ac-LEE and Ac-AgNPs were tested against selected polyphagous insect pests. The significant larval and pupal toxicity were experimentally proven, and the highest toxicity noticed in AgNPs than Ac-LEE. The larval and pupal toxicity of Ac-AgNPs tested against S. litura and H. armigera LC50/LC90 values were 71.04/ 74.78, 85.33/ 88.91 µg/mL and 92.57/ 96.21 and 124.43/ 129.95 µg/mL respectively. Ac-AgNPs could be potential phyto-pesticidal effectiveness against selected polyphagous insect pests. In globally, it is significantly sufficient ratification giving towards the prevention of many unauthorized SCPs. 相似文献