东方鲎消化道上皮的超微结构观察

鉴于目前鲎试剂的应用日趋广泛和鲎资源的逐年减少,人们对其生物学的研究已深入到超微结构领域,但对东方鲎消化道上皮的超微结构,迄今尚未见有专题报道。本文选用成年健康东方鲎(TachypleusTridentatus)2只,根据刘正琮等关于该鲎消化道各段的划分,行活体取材,常规制样,透射电镜观察,旨在进一步阐明其组织结构特点,并为鲎的人工饲养提供某些参考资料。结果如下: 从食道至后肠,其上皮均为密集的单层上皮细胞和极少量的细胞间质组成,食道和胃的上皮细胞呈矮柱状或立方形,幽门和肠则为柱状或高柱状。胞核卵圆形,位于细胞基部或近中部,上皮基部均有基膜,     

胸腺上皮肿瘤的超微结构观察

目的：观察胸腺上皮肿瘤(thymic epithelial tumor,TET)WHO病理分型的超微结构特征。方法：对14例TET采用WHO病理分型,分别观察组织病理学和超微结构的形态学特征。结果：按WHO病理分型诊断胸腺瘤A型1例,AB型3例,B1型1例,B2型4例,B3型3例,C型2例。各型胸腺瘤均具有上皮性肿瘤的结构特点,如：张力原纤维、桥粒等结构;C型胸腺瘤(胸腺癌)异型性很明显,常见肿瘤性坏死,其他类型则有一定程度的异型性。A型胸腺瘤细胞核异染色质丰富,核仁不明显,无异型性;AB型和B1型异型性不明显,细胞核常染色质较均匀,可见小核仁;B2、B3型胸腺瘤异型性较明显,常染色质较丰富,核仁明显,细胞质宽大,有突起。结论：从超微结构特点来看：A型胸腺瘤生长不活跃,AB型和B1型胸腺瘤生长略活跃;B2、B3型胸腺瘤生长较活跃;C型胸腺瘤生长很活跃。     

对大鼠子宫粘膜分泌方式的电镜观察

本实验应用扫描电镜和透射电镜对大鼠非妊娠期子宫粘膜的分泌方式进行了观察。实验结果表明,大鼠子宫粘膜在动情期时出现明显的分泌活动,其分泌方式可分为顶浆分泌,微顶浆分泌和胞吐分泌三种。我们将分泌过程分为静止期、分泌前期、分泌期和分泌后期四个阶段。静止期时,细胞表面有大量密集的微绒毛,细胞内与分泌活动有关的细胞器如粗面内质网和高尔基复合体等不发达。处于分泌前期的细胞,有的顶部膨隆,形成面积较大的隆起或短突;其表面不平,微绒毛稀少且短,愈向四周微绒毛愈多愈长。有的隆起呈花瓣状,表面有许多微褶。在被剖开的圆顶状隆起下方可见大量的球形分泌颗粒(图1)。至分泌期时,细胞表面已形成大小不     

小鼠心房肌分泌心钠素的免疫电镜观察

心钠素(ANF)主要存在于心房肌细胞的特殊颗粒(SG)内。本实验采用给小鼠钠负荷,以促进ANF分泌及禁水使ANF分泌减少的方法,采用放射免疫分析法测定血浆ANF浓度,应用免疫电镜技术观察心房肌细胞的超微结构及ANF颗粒的形态改变,探索心房肌细胞ANF分泌的形态学依据。结果显示钠负荷组小鼠血浆ANF浓度(3.91±1.02)显著高于禁水组(2.73±1.20),P<0.05。免疫电镜观察结果表明,禁水5天后,心房肌内具ANF免疫活性的SG主要集中于核两端肌浆带内,高尔基     

小鼠心房肌分泌心钠素的免疫电镜观察

近来发现,心脏不仅是血液循环的动力器官,而且还具有内分泌功能。例如,有强大利钠、利尿作用的心钠素(ANF)就主要存在于心房肌细胞的特殊颗粒(SG)内。其分泌过程是否与其他内分泌细胞一样,尚不清楚。本实验采用给小鼠钠负荷,以促进ANF分泌;禁水使ANF分泌减少的方法,用免疫电镜技术观察,探讨心房肌细胞分泌ANF的形态学依据。材料和方法:一、动物分组:实验用昆明种小鼠20只,体重29.1±2.6g,随机分为禁水,钠负荷     

兔附睾上皮的免疫组化及超微结构研究

附睾特异性蛋白—1(ESP—1)和—2(ESP—2)是从新西兰家兔附睾尾液中分离出的两种蛋白,对附睾精子的功能性成熟起重要作用。有关这两种蛋白的合成部位及分泌方式尚缺乏统一认识。作者应用免疫细胞化学染色(ABC法和IGSS法)对新西兰雄性家兔附睾上皮进行了研究。光镜和CAM高速计算机图象分析表明,ESP—1和ESP—2在附睾起始段为阴性,从头段开始主细胞胞质内逐渐出现阳性颗粒,在体段呈色反应强于其它各段。在此基础上,为深入探索上皮的分泌方式,超微结构及与光镜组化关系,又进行了扫描电镜观察。电镜结果显示:体部上皮相邻细胞分别具有不同的分泌时相,处于相对静止的细胞,表面覆盖微绒毛;而呈现分泌活动的细胞,其游离面局部常向腔内隆起(图1),隆起内部集结有许多大小不等的圆形或管泡状分泌颗     

人胎儿气管上皮纤毛发生的电镜观察

关于成年哺乳动物气管上皮形态学的研究已有报导 ,但对气管上皮纤毛的发育过程国内尚无报导。本研究对发育过程中的胎儿气管上皮纤毛进行电镜观察 ,有助于我们了解人气管上皮组织发生、形态的改变及了解气管上皮的功能具有重要意义。本研究是采用不同周数的胎儿气管上皮用电镜观察 ,结果可见胎儿气管上皮纤毛的发生、发育过程可分四个阶段。材料和方法( 1 )　取材正常胎儿 ,由中国医科大学附属二院产科提供 (自发终止妊娠的正常发育的十四周到三十一周的胎儿 )。( 2 )　用生理盐水充分冲洗干净 ,分离气管树并将气管分成数段 ,放入固定液中 ,…     

人食管粘膜上皮淋巴细胞浸润过程的电镜观察

食管粘膜在与外源性不良因子接触中,具有较良好的生物学稳衡功能,除粘膜本身的柔韧性、厚度以及上皮细胞快速分裂增生因素外,也应该与上皮内其它相关细胞的主动免疫防御功能息息相关。为了探明后一问题,作者应用超薄切片透射电子显微镜观察法,对人类食管粘膜上皮中淋巴细胞的穿移     

He-Ne激光对家兔淋巴结影响的光镜和电镜观察

以Ｈｅ－Ｎｅ激光局部照射家兔颈前部及穴位照射，取颈前淋巴结进行光镜和电镜观察，同时用单向免疫扩散法测血清ＩｇＧ含量。结果表明，局部照射和穴位照射均能使淋巴结内多种细胞的超微结构发生改变，细胞功能表现活跃。穴位照射组血中ＩｇＧ含量较对照组明显升高。说明Ｈｅ－Ｎｅ激光照射增强机体细胞免疫和体液免疫机能是有细胞学基础的。提示穴位照射能增强全身免疫机能，而局部照射只能增强被照部位的免疫机能     

内耳螺旋器神经纤维及毛细胞突触的电镜观察

毛细胞是内耳螺旋器接受声波震动的感觉性上皮细胞 ,在完成听觉过程中该细胞起着关键性中介作用 ,它的生理功能及微细结构早有学者报道[1,2 ] 。本研究拟从超微结构角度 ,进一步分析毛细胞与传入性及传出性神经终末突触结构的超微特点。材料和方法 :研究样品全部取自正常成年豚鼠 ,雌雄不拘 ,断头处死后自颞侧开颅取出耳蜗 ,随之在蜗顶及骨蜗管外壁剥穿一小孔 ,注入适量固定液 ,然后整体投入磷酸缓冲的 4 %戊二醛固定液内 ,常温下0 5ｈ后剥离蜗管壁 ,沿骨螺旋板外侧剪取螺旋器 ,注意定位。经常规固定脱水 ,树脂包埋 ,半薄切片进行内、外毛…     

话音活动检测的模型及其在移动通信中的应用

本文给出了基于ＡＤＰＣＭ编码的话音活动检测器及其模型，并应用该模型分析了分组预约多址协议的性能。     

科普活动对学校科学教育的价值研究——以某次“水”主题科普活动为例

本文基于一次"水"主题科普活动的教育效果分析,讨论科普活动对于学校科学教育产生的作用和价值。研究表明,科普活动能够促进学生理解科学—技术—社会关系、完善科学知识结构、激发科学学习兴趣。文章同时从拓展参与校外科普活动渠道、营造校外科学学习环境等角度出发,提出利用科普活动促进学校科学教育的建议。     

Electron affinities of organic materials used for organic light-emitting diodes: A low-energy inverse photoemission study

The electron affinity (EA) of an organic semiconductor is a measure of the electron transport level. Although reliable values of the EA are required for designing the device architecture of organic light-emitting diodes (OLED), there were no appropriate methods. Recently we have developed low-energy inverse photoemission spectroscopy which enables us to determine the EA of organic materials in solid with the precision required for research of OLED. Using this new technique, we precisely determined EA of typical OLED materials, TCTA, CBP, Ir(ppy)₃, BCP, Alq₃ and Liq as well as a newly developed dopant 4CzIPN. The obtained electron affinities are generally smaller by about 1 eV than the commonly believed values urging the reconsideration of the electron injection/transport mechanisms in OLED. We also compare EAs determined by various experimental and calculation methods for 29 materials. The results show that the reduction potential gives a reasonable estimate rather than the optical gap and ionization energy.     

The adoption and use of mobile phone in rural China: A case study of Hubei,China

This paper examines the behavioral and psychological factors influencing the adoption and use of mobile phone in rural China. Based on the diffusion of innovations and perceived needs theory, this research, through a case study of Hubei, China, supports the theoretical model that both behavioral and psychological factors can predict Chinese rural residents’ adoption and use of mobile phone. Psychological factors, however, play a weaker role in rural residents’ adoption and use of mobile phone than do behavioral factors. Moreover, behavioral factors can significantly predict some of the psychological factors. By adding behavioral factors into the theoretical model, this study supplements the perceived needs theory and extends it from urban setting to rural setting. Implications of the findings have been discussed.     

The role of regulatory focus in decision making of mobile app download: A study of Chinese college students

This paper aims to map out college consumers’ decision making process in mobile application download. Regulatory focus (RF) is examined as an important factor affecting gratifications sought (GS) and information processing (IP), app selection style and the ultimate mobile app download behavior. Results show that RF has effects on hedonic GS, and heuristic IP and systematic IP. Hedonic GS positively predicts equally both heuristic processing and systematic processing. Both heuristic processing and systematic processing predict selection style. Although selection style does not affect download app type diversity, impulsive style consumers are more likely to download the app. The study also shows college consumers in general have high likelihood in downloading an app after they considered it. Hedonic GS mediates the relation between RF and both heuristic processing and systematic processing. Systematic processing mediates hedonic GS and selection style. Hence mobile app download decision involves both heuristic and systematic processing.     

The effects of social networks on the assessment of virtual learning environments: A study for social sciences degrees

This paper deepens in the study of the appropriateness of virtual learning environments through the use and value of social networks by college students, considering the reliability, confidence and experience of the Internet. The study develop a comprehensive structural equation model conducted among 381college students of different Social Sciences degrees of the University of A Coruna (Spain). The results show that both topical social network and the Internet have a significant influence on college students’ virtual learning environment assessment, regardless the area of study. The analysis also discloses the potential utility of the above interactions on virtual learning environments in terms of downloading of material, improvement in learning efficiency and usefulness of contents, functions and supplement of other learning ICT tools. Findings reveal that the implementation of educational policies that allow adapting virtual learning environments to college students’ preferences are required.     

The associate impact of individual internal experiences and reference groups on buying behavior: A case study of animations,comics, and games consumers

Among the entertainment and media market, it can be observed that animations, comics, and video games (hereinafter abbreviated as ACG) have the highest output value and most market influence. Moreover, ACG also incorporates various industries and creates many derivative products. As the ACG industry emphasizes acousto-optics, imagery, and storylines, personal impressions derived from consumer experiences will influence consumer decisions. In addition, the ACG industry is mainly marketed towards younger age groups, with younger people being the main consumers; as such, these consumers’ decisions are more easily affected by peer behavior.This study aims to analyze the effects of internal cognitions and external influences on buying behavior of ACG consumers by applying the uncomplicated decision tree data mining algorithm. We analyze and develop the target attributes on measures of customer loyalty for ACG industry to set up the decision trees from the collected questionnaire data. The decision tree data mining method is applied to analyze the hidden association rules between the target attributes (i.e., consumer loyalty) and the critical influencing factors of consumer’s internal impressions and external influences for ACG consumers. The results and suggestions of this paper can be used as a reference for enterprises in the ACG industry to help with business policies concerning products’ extensional design, marketing, and CRM, and to further strengthen customer satisfaction and loyalty, thus increasing company profits.     

The aborted Green dam-youth escort censor-ware project in China: A case study of emerging civic participation in China’s internet policy-making process

The educated and affluent Internet users in China have posed great threats to the stability and legitimacy of Chinese communist’s regime where the access of non-government dominated information become a possibility. To restrain Chinese citizens’ access to any Internet contents that are considered to undermine state control, China has developed and implemented one of the most sophisticated multi-layered Internet filtering systems in the world. These projects include the Golden Shield (or Jin Dun) and the Great Fire Walls of China that were implemented in the infrastructure to deter any undesirable or politically sensitive information.     

The effect of growth conditions,point defects and hydrogen on the electronic structure and properties of p-type (Al,N) codoped ZnO: A first principles study

The effects of point defects, hydrogen, and growth conditions on the electronic structure and properties of the (Al,N) codoped p-type ZnO have been investigated using the first principles method. The obtained results showed that the Al_Zn–N_O–V_Zn complex is a shallow acceptor that can play an important role in achieving the p-type conductivity in the (Al,N) codoped ZnO films. Our results showed also that the electrical conductivity type in the (Al,N) codoped ZnO films strongly depends on the donor/acceptor concentrations ratio. The codoped ZnO films prepared under both Zn-rich and O-rich growth conditions with a donors/acceptors ratio of 1:2 have a p-type conductivity, while those prepared with a ratio of 1:1 cannot be p-type unless if they are prepared under O-rich conditions. The achieved p-type quality depends also on the used nitrogen doping source. To prepare p-type ZnO film of high quality using the (Al,N) codoping method, the use of NO or NO₂ is recommended. The presence of donor defects such as oxygen vacancies and hydrogen will significantly affect the electronic properties of the (Al,N) codoped ZnO films, and if the concentration of these defects in the sample is high enough, the material can be easily converted to n-type.     

The effect of Zn1‐xMgxO buffer layer deposition temperature on Cu(In,Ga)Se2 solar cells: A study of the buffer/absorber interface

The effect of atomic layer deposition temperature of Zn_1‐xMg_xO buffer layers for Cu(In,Ga)Se₂ (CIGS) based solar cell devices is evaluated. The Zn_1‐xMg_xO films are grown using diethyl zinc, bis‐cyclopentadienyl magnesium and water as precursors in a temperature range of 105 to 180°C. High efficiency devices are produced in the region from 105 up to 135°C. At a Zn_1‐xMg_xO deposition temperature of 120°C, a maximum cell efficiency of 15·5% is reached by using a Zn_1‐xMg_xO layer with an x‐value of 0·2 and a thickness of 140 nm. A significant drop in cell efficiency due to large losses in open circuit voltage and fill factor is observed for devices grown at temperatures above 150°C. No differences in chemical composition, structure and morphology of the samples are observed, except for the samples prepared at 105 and 120°C that show elemental selenium present at the buffer/absorber interface. The selenium at the interface does not lead to major degradation of the solar cell device efficiency. Instead, a decrease in Zn_1‐xMg_xO resistivity by more than one order of magnitude at growth temperatures above 150°C may explain the degradation in solar cell performance. From energy filtered transmission electron microscopy, the width of the CIGS/Zn_1‐xMg_xO chemical interface is found to be thinner than 10 nm without any areas of depletion for Cu, Se, Zn and O. Copyright © 2008 John Wiley & Sons, Ltd.