LambdaDNA诱导非细胞体系核重构过程的超微结构研究

非洲爪蟾未受精的卵细胞去胶膜后,经钙离子载体A23187活化及松胞素B处理,10,000G离心裂胞,除掉脂滴、卵黄颗粒、色素颗粒及卵核等,可得到可溶性胞质。在可溶性胞质中先加入ATP再生系统。将在65℃处理5分钟的Lambda DNA引入上述爪蟾卵非细胞体系,置22℃温育。以温育开始为零时,每隔一定时间取样固定做电镜观察,共取到温育4小时。取出的样品用戊二醛、锇酸双固定,Epon812包埋后做超薄切片,经醋酸双氧铀——柠檬酸铅染色,在JEM-100CX透射电镜下观察。同时按常规方法做冰冻蚀刻观察。     

大鳍鳠卵发生中溶酶体超微结构变化与卵膜发生

大鳍鳠卵细胞发生中的溶酶体结构变化活跃,Ⅰ期卵原细胞胞质内可见线粒体、高尔基体和少量呈球状的初级溶酶体。Ⅱ期卵母细胞胞质内可见多个球状溶酶体,溶酶体内的水解酶蛋白呈结晶态,多紧贴线粒体部分分布。卵母细胞质膜绉缩,胞质边缘可见大量球状和线状溶酶体分布。Ⅲ期卵母细胞内侧出现绒毛状卵膜结构,外侧出现“放射带”,球状的初级溶酶体结构消失,绒毛状卵膜与放射带之间可见大量线状溶酶体结构。推测球状溶酶体和线粒体间接参与了卵母细胞质膜的绉缩位移;而线状溶酶体则可能直接参与了绒毛状卵膜和“放射带”结构的形成。     

非细胞体系核重构的过程及重构核活性的研究

我们首先利用 Lambda DNA 与活化的非洲爪蟾卵提取物进行了非细胞体系核重构,并在此基础上对核重构过程的超微结构与重构核的功能进行了研究。将活化约半小时后的非洲爪蟾卵在10,000G分离心除去脂类,卵黄,色素及卵核后得到卵提取物(extracts),它们由大量的线粒体,各种大小的膜泡及均匀的基质构成;将它们在22℃温育一定时间后,可以观察到有很多环形片层结构出现;在活化体系中加入 Lambda DNA 后温育,可以观察到核重构现象。重构核具有完整的双层膜及典型的核孔结构。电镜核酸分子原位杂交结果证明重构核     

基于微流控的人卵母细胞特性检测

人的卵母细胞特性的研究对于临床医学具有重要意义,可以通过卵母细胞的大小对其活性进行研究。采用微流控平台与MATLAB算法相结合的方法,利用微流控器件的沟道对卵母细胞进行挤压,由于卵母细胞的活性不同对于挤压的反应也不同,活性越好的卵母细胞通过沟道时变形性越好,经检测卵母细胞有很好的活性;拍摄卵母细胞发生形变与卵母细胞通过沟道的视频,利用MATLAB程序进行图像处理得到卵母细胞的大小,测得卵母细胞的直径约为170μm。这种方法有别于传统方法,在一定程度上使用了算法识别,提高了卵母细胞分析统计的准确度,提升了工作效率。由于人的卵母细胞比较珍贵,只进行了初期实验研究,证明此方法确实可行。     

非洲爪蟾卵提取物中环形片层及其核孔复合体的自发形成

用超薄切片电镜技术结合冰冻蚀刻方法观察到在活化的爪蟾卵提取物中环形片层能够自发地大量形成,核孔复合体的超微结构与天然的核孔复合体没有区别,表明核孔复合体的装配能够不依赖于染色质或DNA的诱导而独立进行。进一步研究发现,在上述非细胞体系中,核孔复合体的自发装配需要可溶性组份与膜泡部分的共同参与,说明核孔复合体这种蛋白质性质的细胞器与膜物质有很密切的关系。活化的非洲爪蟾卵提取物为我们深入研究核孔复合体的装配及环形片层与核被膜的关系提供了一个很好的实验模式。     

玉竹花粉中造粉质体形成及增殖的超微结构研究

本文运用电子显微镜技术研究了玉竹花粉中造粉质体形成及增殖的超微结构特点，发现造粉质体在体积增加的过程中与内质网有密切关系，造粉质体除以分裂的形式进行增殖外可能还有其他的形式，分裂过程中在颈部出现分裂中的作用及其他可能的分裂机制进行了讨论。     

利用大肠杆菌DNA和DNA酶切小分子片段进行细胞核的体外装配

利用大肠杆菌ＤＮＡ和ＤＮＡ酶切小分子片段进行细胞核的体外装配蒋争凡赵国燕刘春香翟中和（北京大学生命科学学院，北京１００８７１）近年来我们实验室成功地将多种生物的ＤＮＡ在非洲爪蟾（Ｘｅｎｏｐｕｓｌａｅｖｉｓ）卵提取物中实现了非细胞体系核装配［１，２］。...     

核体及其贴壁过程的超微结构研究

核体是松胞素诱导组织培养细胞排核的产物。近年来已有许多学者利用核体来研究细胞生命活动的一些基本问题。本文利用透射电镜和扫描电镜对核体及其贴壁过程的超微结构进行了研究。将核体制成超薄切片,可以观察到用松胞素B与冲刷法制备的核体是由完整的质膜和不等量的胞质及其所包被的细胞核组成,其细胞核内精细结构保存完好(图1),显而易见核体具有完整的质膜和少量的胞质的保护,这对于维持细胞核的精细结构是非常重要的。裸核由于缺乏质膜和胞质,其内部结构则发生退行性变化。在静置培养条件下,核体仍具贴壁的能力。用扫描电镜观察,可看到核体在贴壁过程中,能形成与基质面接     

紫花补血草的大小孢子发生及雌雄配子体发育

利用常规石蜡制片法研究了紫花补血草的大小孢子发生及雌雄配子体的发育过程.结果表明:(1)花药壁由表皮、药室内壁、2层中层和绒毡层共5层细胞构成.花药壁发育类型为基本型.表皮细胞内贮藏单宁类物质.药室内壁有纤维性加厚.绒毡层为分泌型绒毡层,成熟绒毡层细胞含2核.(2)小孢子母细胞减数分裂过程中胞质分裂为同时型.小孢子四分体四面体型排列.(3)成熟花粉粒为3.细胞型.(4)胚囊发育类型为贝母型.(5)卵细胞的细胞核位置较为特殊,不是靠近合点端,而是靠近珠孔端.(6)八核胚囊在分化为成熟胚囊时,卵器的细胞常退化.(7)存在过度发育的胚囊.(8)具双胚囊现象.     

血卟啉衍生物(HPD)-光辐射对Beap-37人乳癌细胞系杀伤效应的实验研究

HPD-激光对Bcap-37人乳癌细胞系有显著的杀伤作用.HPD-激光作用后,癌细胞最早出现的形态学变化是线粒体的肿胀破坏,细胞色素氧化酶与琥珀酸脱氢酶活性也不同程度地受到抑制.其损伤依次表现为细胞团缩、胞浆内空泡形成、染色体质凝集、胞体肿胀和核碎裂.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.