扁藻细胞电镜观察的制样技术     

邹宁  魏丕伟  肖波  孙育平  王艳华 《烟台职业学院学报》2004,10(3):73-75

以海洋单细胞微藻亚心型扁藻为材料 ,对海水水样中活体单细胞微藻的亚显微结构观察样品的制备技术进行了探索。选用 2 .5 %的戊二醛固定液和 1 %的锇酸固定液对样品进行双固定的技术 ;先酒精后丙酮按浓度梯度顺次进行脱水 ;再用Epon81 2环氧树脂作为包埋剂进行包埋 ;最后经过醋酸铀 -枸橼酸铅双染色后将切片用透射电镜进行亚显微结构的形态观察。采用本方法进行水样中活体样品的电镜制片 ,拍得清晰度较高的电镜照片 ,并通过照片对水样中运动细胞透射电镜样品制备技术进行了分析。  相似文献   

针刺和静力牵张对大负荷运动后骨骼肌M线变化影响的免疫电镜研究   总被引：4，自引：1，他引：3  

屈竹青  樊景禹  卢鼎厚 《体育科学》1992,(6)

用胶体金标记技术定位运动后及运动后经针刺或静力牵张处理的人骨骼肌M蛋白,以探讨超过习惯负荷后骨骼肌收缩结构变化以及针刺和静力牵张对促进其恢复的机制。我们发现:大负荷斜蹲后未经针刺的对照腿股外肌M线的M蛋白标记密度低于针刺腿(P<0.05),而对照腿M线两侧及M线两侧以外的M蛋白标记密度高于针刺腿(P<0.05)。对照实验证明运动腿M线以外增加的标记物为物异性标记。静力牵张组在M线及M线两侧的标记结果与针刺组一致。仅在M线两侧以外区域牵张腿与运动对照腿之间标记密度的差异没有统计学意义。我们还观察到运动后对照腿变化M线体密度达42—48％,而针刺或牵张腿为6—9％。上述结果表明大负荷运动加强了负荷后骨骼肌M蛋白的解聚或降解,从而导致M线结构改变;针刺和静力牵张可显著促进M蛋白的合成或抑制其降解,而使M线结构恢复或稳定。本文还探讨了M线变化与肌粗丝结构变化的关系。  相似文献   

运动后低氧暴露对血液流变学及红细胞形态的影响   总被引：4，自引：0，他引：4  

包大鹏  胡扬  田野  雷雨晨  河春姬 《体育科学》2005,25(4):28-31

研究目的：观察常氧运动后低氧暴露情况下血液流变学及红细胞形态的变化。研究方法：8名受试者以75％ VO2max强度分别完成2次1h蹬功率自行车运动，间隔1周。第1周受试者以75％ VO2max强度蹬功率自行车1h后即进入低氧室内(氧气浓度：15．4％，相当于海拔2500m)休息30min。第2周同一时间，受试者以同等负荷运动1h后常氧环境休息30min。每次实验分别于安静时、运动后即刻、运动后30min采取静脉血5ml，测血液流变学变化和扫描电镜(SEM)下观察红细胞形态变化。结果：运动后血液粘度升高，红细胞变形能力下降，红细胞形态由双凹圆盘状变为单侧凹陷另一侧隆起似礼帽状的I型口形红细胞。结论：运动后低氧暴露不利于血液流变学及红细胞形态的恢复。  相似文献   

Seeking Nettle Textiles – Utilizing a Combination of Microscopic Methods for Fibre Identification     

Jenni A. Suomela  Krista Vajanto  Riikka Räisänen 《文物保护研究》2018,63(7):412-422

Bast fibres have been commonly used as a textile material in Northern Europe since Neolithic times. However, the process of identifying the different species has been problematic, and many important questions related to their cultural history are still unanswered. For example, a modified Herzog test and the presence of calcium oxalate crystals have both been used in identification. In order to generate more reliable results, further research and advancement in multi-methodological methods is required. This paper introduces a combination of methods which can be used to identify and distinguish flax (Linum usitatissimum), hemp (Cannabis sativa), and stinging nettle (Urtica dioica). The research material consisted of reference fibres and 25 fibre samples obtained from 12 textiles assumed to be made of nettle. The textiles were from the Finno-Ugric and Historical Collections of The National Museum of Finland. The fibre samples were studied by observing the surface characteristics and cross sections with transmitted light microscopy, and by using a modified Herzog test with polarized light, in order to identify the distinguishable features in their morphological structures. The study showed that five out of 25 samples were cotton, 16 nettle, one flax, and one hemp. Findings from two samples were inconsistent. The results show that it is possible to distinguish common north European bast fibres from each other by using a combination of microscopic methods. Furthermore, by utilizing these combined methods, new and more reliable information could be obtained from historical ethnographic textiles, which creates new vistas for the interpretation of their cultural history.  相似文献   

Virtual Microscopy as a Learning Tool in Brazilian Medical Education     

Fernanda Somera dos Santos  Mariana Kiomy Osako  Gleici da Silva Castro Perdoná  Márcia Gaião Alves  Katiuchia Uzzun Sales 《Anatomical sciences education》2021,14(4):408-416

Virtual microscopy (VM) is a widely used teaching method in Medical Education in many developed countries. In Brazil, however, this is not the case for most medical schools, considering Brazilian social inequality and uneven access to technology. Recently, the Covid-19 pandemic has also challenged Universities to seek and make a transition toward more effective methods of full-time online education. Thus, the main goal of this work was to verify student's perception and academic performance, assessed upon VM implementation in a Brazilian Medical School. Ribeirao Preto Medical School students answered a 26-question survey with regards to optical microscopy (OM) and VM. Academic performance was compared between participants that were (year of 2019) or were not (year of 2015) exposed to VM. Taken the results together, subjective impressions such as handling, suitability, learning effectiveness, and pleasure using the tools, have shown a higher score for virtual microscopy (median = 29), when compared to optical microscopy (median = 24) with a P-value < 0.001 by Wilcoxon rank test, upon measurement using an ordinal scale. Regarding academic performance, no statistically significant differences were found between groups (P-value = 0.38, Cohen's d = 0.19). Therefore, VM proved to be adequate to the Brazilian medical education in light of Brazilian social contexts and Covid-19 pandemic.  相似文献   

基于波束扫描的DBF天线方向图测试方法     

周建卫  李道京  胡烜 《中国科学院大学学报》2016,33(4):542-547

DBF天线安装后，一般不具备可机械旋转的常规测试条件。研究DBF天线方向图的间接测试问题，提出一种基于波束扫描的测试方法，给出其测试原理和测试流程。针对波束宽度、副瓣水平和波束指向等天线主要参数，用仿真比对该方法与常规方法的测试结果和误差。在DBF天线方向图正常和异常两种情况下，两种方法可得到相近的仿真测试结果，证明间接测试方法的有效性。  相似文献   

三甲基铝双聚体的结构和键合作用     

刘亨  李业霞 《滨州学院学报》2001,17(4):55-57

以杂化理论、闭合的三中心两电子键模型对Al2 (CH3 ) 6之键角、键长等作出合理的解释 ,明确Al2 (CH3 ) 6的空间构型  相似文献   

拓扑指数mP在价电子轨道能量中的相关性研究     

赵旭升 《青海师专学报》2007,27(5):95-97

本文提出了一种新的键参数拓扑指数^mP.用其零、一阶指数0p、1p分别与20种碱金属卤化物的晶格能U、生成焓△Hf,m,离子水化能△Gh,m和核间距R0以及16种碱金属卤化物的熔点Tm、磁化率xm和键长Bd的相关联,采用最小二乘法,拟合的回归方程的相关系数分别为0.995、0.988、0.996、0.995、0.964、0.988、0.964,满足优级标准,预测结果良好.  相似文献   

电子类教学仪器的抗振防振设计     

蓝军 《中国教育技术装备》2005,(1):17-18

对电子教学设备的抗振从理论和实践上进行了探讨，并介绍了电子类教学设备的抗振设计原则和方法。  相似文献   

探讨英语快速阅读的问题与技巧   总被引：4，自引：0，他引：4  

张彩云  刘海奋 《延安教育学院学报》2006,20(1):73-74,77

信息时代的信息爆炸,学生时代的应试之需,提高快速阅读能力,势在必行。掌握必要的阅读技巧,克服不良的主客观因素,将是提高快速阅读能力的关键。  相似文献