高压冷冻及冷冻替代技术在不同生物样品超微结构中的应用

高压冷冻仪在固定样品时,高压和冷冻基本是同步发生的,使得生物样品在数毫秒的时间内被瞬时固定,保证其内部结构接近于生理状态,有效减少了化学固定法中的化学试剂对细胞结构的破坏,极大程度保存了细胞在近似自然状态下的超微结构.本文分别采用化学固定法(CF)和高压冷冻固定法(HPF)对小鼠的睾丸组织、Hela细胞和酵母进行了样品...     

高压冷冻-冷冻替代技术在神经组织超微结构中的应用

采用高压冷冻-冷冻替代技术对小鼠和线虫这两种模式生物的神经组织进行了样品制备、超薄切片和电镜观察,并在取材方式上进行了摸索,旨在比较化学固定法(CF)、高压冷冻固定法(HPF)和化学-高压冷冻联合固定法(CF+ HPF)三种不同方式对神经组织超微结构的影响,促进高压冷冻-冷冻替代技术在神经生物学中的应用.透射电镜观察结果显示:与传统的化学固定相比,高压冷冻固定对神经组织样品具有较好的优势,能够减少化学处理所产生的人工假象;另一方面,对于不同动物的神经组织而言,所适用的固定方式也不相同,鼠脑适用于活检枪(biopsy gun)取样后直接进行HPF固定,所得结构比较完整,神经组织微观结构清晰.而在高压冷冻之前选用CF进行预固定,能加大样品结构保存的完整性,但在膜的细腻程度上不如直接进行高压冷冻制样的结果.线虫样品由于存在较厚的体壁保护,它更适于直接进行HPF处理,从而缩短了固定前的滞留时间,可有效保留腹部神经元超微结构.     

高压冷冻技术在拟南芥细胞微结构研究中的应用

高压冷冻技术是指以高压冷冻固定为主要内容的一种电镜技术。该技术可以充分、快速固定样品的同时,避免引入操作干扰,使得电镜结构更接近样品生活状态。本文利用拟南芥为材料,比较了高压冷冻固定及冷冻替代制备的电镜样品同常规化学固定、室温梯度脱水方法所制备样品的差异。结果显示,在拟南芥根及叶片中,高压冷冻技术可以有效地避免常规制备样品中的细胞壁收缩,细胞质不均匀分布,高尔基体及质体收缩,细胞膜及液泡膜皱缩甚至断裂等现象,使细胞结构更接近其生活时的状态。     

一种用于标记蓝宝石盘的高压冷冻制样辅助装置

高压冷冻技术(high pressure freezing,HPF)是近年来出现的一种可以更有效保存样品原始结构的制样方法.本文介绍了针对高压冷冻制样过程中,无法区分用于培养细胞的蓝宝石盘正反两面的问题,使用3D打印技术制作模具进行喷涂特殊样式的碳膜标记,从而得以区分蓝宝石盘正反面,提高制样成功率.     

高压冷冻技术及其在植物细胞超微结构中的应用

冷冻固定技术可以将生物组织和细胞内所有结构和成分同时固定。因此避免了因化学渗透固定而引起的各种假象。通常,在常压下冷冻技术仅能使生物样品表面１０～３０μｍ厚度得以充分固定,而高压冷冻技术则能使样品有效固定厚度增加至６００μｍ。尽管植物组织细胞具有特殊的结构－厚壁和含大量水分的液泡,使冷冻固定较为困难,但利用高冷冻技术仍能使２００μｍ厚度的样品得到充分固定,而且能够捕获近似自然状态的细胞超微结构。本     

肾组织的低温快速冷冻固定及冷冻置换研究

超低温快速冷冻固定以极高的冷冻速率对生物样品进行固定,可使生物组织结构、组织内可溶性离子及游离性物质得到保存,使被固定后的生物组织仍旧保持于最接近原自然状态。作者对肾组织的超低温快速冷冻固定及冷冻损伤进行了探讨。取雄性大鼠肾皮质用振动切片机切成150～200/μm厚的薄片,采用Reichert-Jung KF-80弹射式快速冷冻仪将切片快速插入经液氮冷冻至-175℃的冷冻剂F22中,再迅速转移到置换液丙酮中,并保持温度在-80℃(34小时);-60℃(48小时);-20℃(12小时)和-4℃(1小时),缓慢升至室温。常规包埋切片并观察。电镜下,从肾皮质表层到30μm深的范围内,组织超微结构保存良好,细胞核、核仁和微绒毛等结构清晰显     

高压冷冻及冷冻替代样品制备方法在体扫描电镜中的应用

高压冷冻及冷冻替代技术是一种利用高压和低温对含水组织样品进行瞬间冷冻固定和低温脱水的电镜样品制备技术,它因可以保存更加真实的细胞超微结构而常应用于透射电镜观察和分析。本文利用模式动物小鼠为材料,将这种技术应用于体扫描电镜的样品制备,并与常规化学固定的样品制备进行比较。结果显示在小鼠心肌组织中,高压冷冻及冷冻替代技术可以有效避免常规制备样品中的细胞器膜结构皱缩、细胞质分布不均匀、细胞核膜收缩形成锯齿状、甚至局部断裂等现象,使细胞超微结构更接近其生活时的状态。     

冷冻电镜含水切片技术观察胰岛β细胞的三维超微结构

冷冻电镜含水切片技术(CEMOVIS)作为冷冻厚生物样品制备技术，对高压冷冻的样品直接进行冷冻切片，能够获得完全含水状态的生物样品的超微结构，更好地反映出细胞接近其生理条件的真实状态。本文应用冷冻含水切片技术结合冷冻电子断层扫描和三维重构技术观察到了小鼠胰岛β细胞内细胞器的高分辨超微结构。     

感染番茄斑萎病毒和番茄环纹斑点病毒的植物叶片细胞病理变化观察

应用透射电子显微镜观察比较了番茄斑萎病毒（ TSWV）和番茄环纹斑点病毒（ TZSV）感病植物叶片的细胞超微结构,发现两种病毒在病变细胞内的形态及细胞病理变化特征相似,但病毒含量及细胞受损程度存在明显差异。与TSWV相比,TZSV侵染细胞的病变程度更为严重,叶绿体产生大的囊泡,片层结构被破坏,线粒体也发生囊泡化,而TSWV侵染的细胞内线粒体保存相对完好。高压冷冻－冷冻置换制备的样品细胞病理结构与常规化学固定的相似,但对膜结构的保存更加良好。该结果从细胞病理学上证明了TZSV在田间对农作物造成的危害更加严重。     

急速冷冻冷冻置换方法保存的肾小球毛细血管袢的超微结构

目的：用急速冷冻－冷冻置换法与普通的9化学固定技术研究比较肾小球毛细血管袢在相同灌流压条件下的超微结构。方法：用150cmH2O压力灌流活体状态下大白鼠的肾脏,用急速冷冻－冷冻置换法及普通的化学固定法制作电镜超薄切片。结果：在相同的压力下用急速冷冻－冷冻置换法所观察到的肾小球毛细血管袢上皮细胞足突裂孔膜的宽度比普通的固定方法所观察到的窄,另外用急速冷冻－冷冻置换方法观察到的肾小球毛细血管袢的其它超微结构也与普通的化学固定方法所观察到的有所不同。结论：用急速冷冻－冷冻置换法所[观察到的超微结构比用普通的化学固定法观察到的超微结构更接近活体状态。     

Effects of different fixation and freeze substitution methods on the ultrastructural preservation of ZYMV-infected Cucurbita pepo (L.) leaves

Different fixation protocols [chemical fixation, plunge and high pressure freezing (HPF)] were used to study the effects of Zucchini yellow mosaic virus (ZYMV) disease on the ultrastructure of adult leaves of Styrian oil pumpkin plants (Cucurbita pepo L. subsp. pepo var. styriaca Greb.) with the transmission electron microscope. Additionally, different media were tested for freeze substitution (FS) to evaluate differences in the ultrastructural preservation of cryofixed plant leaf cells. FS was either performed in (i) 2% osmium tetroxide in anhydrous acetone containing 0.2% uranyl acetate, (ii) 0.01% safranin in anhydrous acetone, (iii) 0.5% glutaraldehyde in anhydrous acetone or (iv) anhydrous acetone. No ultrastructural differences were found in well-preserved cells of plunge and high pressure frozen samples. Cryofixed cells showed a finer granulated cytosol and smoother membranes, than what was found in chemically fixed samples. HPF led in comparison to plunge frozen plant material to an excellent preservation of vascular bundle cells. The use of FS-media such as anhydrous acetone, 0.01% safranin and 0.5% glutaraldehyde led to low membrane contrast and did not preserve the inner fine structures of mitochondria. Additionally, the use of 0.5% glutaraldehyde caused the cytosol to be fuzzy and partly loosened. ZYMV-induced ultrastructural alterations like cylindrical inclusions and dilated ER-cisternae did not differ between chemically fixed and cryofixed cells and were found within the cytosol of infected leaf cells and within sieve tube elements. The results demonstrate specific structural differences depending on the FS-medium used, which has to be considered for investigations of selected cell structures.     

A new device for high-pressure freezing of cultured cell monolayer using 10-microm-thin stainless discs as both culture plate and specimen carrier

High-pressure freezing (HPF) has been generally accepted as the most reliable method for cryofixation of biological samples, yielding a deep vitreous freezing. In recent cell biology, mammalian cultured cells are widely used, but HPF of cultured cell monolayer has not reached its full potential. In this study, we developed a new reliable device for HPF of cultured cell monolayer by using a 10-microm-thin stainless disc both as culture plate and specimen carrier. We describe the practical procedure, and demonstrate fine structures of HeLa cells cultured and cryofixed on the stainless discs as results.     

二种固定方法对扫描电镜用植物细胞冷冻割断样品的影响

本文用冷冻割断法在扫描电镜下观察了大蒜(Allium sativum L.)根尖分生组织细胞内部的三维结构。样品制备采用了两种固定方法:冷冻割断前只用1％的锇酸固定的材料易在细胞质和细胞核之间断开;而先用Bouin‘s液固定,再用1％锇酸固定的材料易使细胞核被断开。据此认为前一固定法适于研究细胞质的内部结构(如细胞骨架纤维、线粒体、内质网等)及其三维分布关系;后一种固定法适于核内结构(染色质、核仁、核基质纤维)的三维图象的研究,特别是核仁纤维中心染色质的三维结构。     

Far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge triple-junction solar cell under forward DC bias

The far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge solar cell are investigated under forward DC bias at room temperature in dark conditions. An electroluminescence viewgraph shows the clear device structures, and the electroluminescence intensity is shown to increases exponentially with bias voltage and linearly with bias current. The results can be interpreted using an equivalent circuit of a single ideal diode model for triple-junction solar cells. The good fit between the measured and calculated data proves the above conclusions. This work is of guiding significance for current solar cell testing and research.     

Study of the Formation of Bubbles in Rigid Substrate-Flexible Substrate Bonding Using Anisotropic Conductive Films and the Bubble Effects on Anisotropic Conductive Film Joint Reliability

The formation of process-related bubbles that become entrapped inside the anisotropic conductive film (ACF) layer during bonding processes remains an issue. The formation of these bubbles is strongly influenced by the process variables, such as bonding pressure and bonding temperature. Therefore, bonding process variables of bonding temperature, bonding pressure, and type of flexible substrate (FS) were changed in order to investigate the effects of the changes as they concern the formation of bubbles. According to the results, the tendency toward bubble formation was closely related to these three factors. The bubble area increased as the bonding temperature increased. Moreover, the shape and tendency of bubbles coincided with temperature distribution in␣the ACF layer. Two different types of FS, each with different surface roughnesses and energies, were used. The bubbles formed only on the FS with the larger roughness and lower surface energy. According to the results from a surface energy measurement of FS types using goniometry, a FS with a higher surface energy is favorable for a bubble-free assembly, as the higher surface energy provides better wettability. In addition, in order to investigate the effect of bubbles on the reliability of ACF joints, the pressure cooker test (PCT) was performed, and all samples with bubbles electrically failed after 72 h of a PCT, as the process-related bubbles provided a moisture penetration path and entrapment site for moisture. However, all type 1 test vehicles (TVs) survived even after 120 h of a PCT. Therefore, Ar and O₂ plasma treatments were performed on the FS with the lower surface energy in order to improve the surface energies and wettability. Following this, the bubbles were successfully removed at rigid substrate (RS)–FS bonding joints using ACFs.     

Isomers of dialkyl diketo-pyrrolo-pyrrole: Electron-deficient units for organic semiconductors

Diketo-pyrrolo-pyrrole (DPP) is an important electron-deficient unit, and the alkylation of DPP can gives rise to good solubility of organic and polymer semiconductors in solvent. In this paper, we report our observations on the isomers of dialkyl DPP. The alkylation of DPP can take place on both the nitrogen and oxygen atoms, leading to the formation of three isomers. The presence of the isomers is evidenced by the nuclear magnetic resonance (NMR) and mass spectra. The yields of the isomers are affected by the experimental conditions, including the reaction temperature, reaction time and solvent. The isomers have different electronic structures and optical properties as revealed by the UV–Vis absorption spectroscopy, fluorescent spectroscopy, cyclic voltammetry and theoretical simulation using Gaussian 03 program with B3LYP/6-31G(d). Small molecules based on the DPP isomers with dialkylation at different sites were synthesized and investigated as donor materials of organic solar cells (OSCs). The photovoltaic performances of OSCs are consistent with the electronic structures of the DPP isomers.     

多晶硅压力传感器的研制

<正> 一、引言 多晶硅作为一种压阻材料,可以通过化学汽相淀积工艺淀积在陶瓷,玻璃,SiO_2,Si_3N4等绝缘材料上,从而制造出一种SOI结构的压力传感器,选种特性为高温压力传感器和更为灵敏的触敏传感器提供可靠的工艺基础。 多晶硅压力传感器避免了扩散型压力传感器的pn结漏电问题,展宽了器件的工作温度范围,高温可达200℃。同时多晶硅电阻的温度系数随掺杂浓度可调,在一定掺杂水平可制造     

Design and Optimization of Gradient Interface of p-Type Ba0.3In0.3FeCo3Sb12/Bi0.48Sb1.52Te3 Thermoelectric Materials

A series of p-type Ba_0.3In_0.3FeCo₃Sb₁₂/Bi_0.48Sb_1.52Te₃ (FS/BT) thermoelectric (TE) materials containing one gradient layer (1GL) with FS/BT volume ratio of 5:5, 3GLs-I with 7:3–5:5–3:7, 3GLs-II with 3:7–5:5–7:3, and 3GLs-III with 3:7–5:5–3:7 from FS to BT were fabricated by a two-step spark plasma sintering method. The interface structure and mechanical properties of the p-type FS/BT TE materials were investigated in this work. Designing the GLs at the interface of FS and BT bulk TE materials can effectively relax the thermal stress induced by the large difference in thermal expansion coefficient and eliminate the macroscopic cracks that occur in FS/BT TE materials with no GL, hence resulting in a remarkable enhancement in the interface mechanical properties of the FS/BT TE materials with the GLs. The optimized gradient interface of the FS/BT TE materials is 3GLs-II with FS/BT volume ratio of 3:7–5:5–7:3. The highest flexural strength of the 3GLs-II sample reached 13.68 MPa, increased by 116%.