Characterization of an endo-1,4-β-glucanase from Lilium longiflorum that functioned in pollen germination and pollen tube growth

Endo-β-glucanases play vital roles in the regulation of pollen tube growth. Here, a previously identified endo-l,4-β-glucanase from Lilium Iongiflorum （lily）, named LlpCell, was expressed in Escherichia coli, purified, and further investigated for its physiological function. The recombinant LlpCell protein hydrolyzed carboxy-methylcellulose （CMC） and exhibited activity towards laminarin from Eisenia. arborea and 1,3：l,4-β-glucan of barley. The pH for the optimum activity was 6.0 and the value of Km calculated from CMC was 5.0 mg/mL. Adding EDTA resulted in the total loss of the enzymatic activity, and this effect could be restored by the addition of Ca^2＋. Western blotting analysis showed that LlpCell protein was present in pollen grains and rehydrated pollen grains, and the amount of the protein was increased during pollen germinating, but not in the pollen tube. Consistently, the immunofluorescence labeling study with the antibody against LIpCell also indicated the presence of LIpCell at the begin-ning of germination, but not in the elongating pollen tube. Furthermore, incubation of LlpCell with pollen at the beginning of pollen germination increased the germination percentage and the length of pollen tube. All of these results suggested that LlpCell could play an important role in the regulation of lily pollen germination and the initiation of pollen tube growth.     

基于可用性工程思想的网络地图界面设计—以南京师范大学校园网络地图为例

在对目前网络地图及其界面设计相关研究进行调研与分析的基础上,发现已有的网络地图界面设计缺乏对用户因素的考虑.本文引入可用性工程及设计方法,将其与网络地图界面设计的各个方面相结合,探讨了基于可用性工程思想的网络地图界面设计的过程与方法.以南京师范大学校园网络地图界面设计为例,按照可用性工程的设计思路,设计了针对不同用户功能需求的校园网络地图界面.     

FITC标记的GSTP1蛋白在鼠巨噬细胞中的定位

GSTP1(GSTπ)是人体内谷胱甘肽-S-转移酶(GST)的一种重要的活性亚型,属于机体内源性蛋白,不会引起免疫原反应,在维持细胞的正常机能中发挥着重要作用,也是一种具有临床应用价值的抗氧化剂.本实验室在研究中首先发现GSTP1具有明显的抗炎作用,由此我们设想可以通过增加外源性的GSTP1蛋白来提高其在机体内的水平,以此增强机体的抗炎能力.本实验将薄层色谱扫描和SDS-PAGE相结合用于FITC标记蛋白质的检测,使用激光共聚焦显微镜和流式分析相结合的方法研究了外源GSTP1蛋白在RAW264.7巨噬样细胞和鼠腹腔巨噬细胞中的跨膜转位,结果显示外源GSTP1蛋白能够进入上述细胞.该研究为GSTP1蛋白作为直接使用的药物在抗肿瘤、抗炎、抗氧化等领域的应用提供了实验基础.     

Lasing on pyroclastic rocks: A case study of <Superscript>40</Superscript>Ar/<Superscript>39</Superscript>Ar dating on Moshishan Group,eastern Zhejiang Province

It is difficult to date pyroclastic rocks, for almost all the dating methods, due to the multiple sources during their formation. ^40Ar/^39gAr incremental heating results on groundmass selected from the samples show that the age spectra are meaningless geologically. However, singe crystal total fusions of CO2 lasing on the sanidine separates could yield rational 4^40Ar/^39Ar results and distinguish their sources in this study. Timing on three formations of the Moshishan Group, after avoiding the exotic and altered grains by lasing on the single sanidine separate, was reported in this paper. The lowermost portion of the Chawan Formation gives an age of 113.7±0.3 Ma; the lower part of the Xishantou Formation was formed 116.4±0.4 Ma ago and the bottom of the Gaowu Formation took its shape at 118.4±0.4 Ma. These new ages are much younger than the previous ones, suggesting that these thick volcanic formations had been formed in very short durations.     

Conformations and adsorption behavior of poly（allylamine hydrochloride） studied by single molecule force spectroscopy

Poly（allylamine hydrochloride） （PAH）, which is frequently used in fabricating polyelectrolyte multilayer films, was studied by single molecule force spectroscopy （SMFS）. Plenty of force-extension curves with a long plateau were obtained in water, indicating that train-like structure was predominant when PAH was adsorbed on the substrate. It was found that the peak-type force-extension curves of PAH in water were not able to be fitted by the modified freely-jointed chain model. Additionally, there was a flat region in the derivative of force-extension curves. Thus, it was inferred that PAH chain in water was in a special conformation and underwent a ＂conformational transition＂ under the stretching of an external force. This phenomenon did not appear in the SMFS experiment in 1 mol/L urea solution, which indicated that urea was able to break the special conformation.     

Verification of GRAPES unified global and regional numerical weather prediction model dynamic core

During the past few years, most of the new developed numerical weather prediction models adopt the strategy of multi-scale technique. Therefore, China Meteorological Administration has devoted to developing a new generation of global and regional multi-scale model since 2003. In order to validate the performance of the GRAPES （Global and Regional Assimilation and PrEdiction System） model both for its scientific design and program coding, a suite of idealized tests has been proposed and conducted, which includes the density flow test, three-dimensional mountain wave and the cross-polar flow test. The density flow experiment indicates that the dynamic core has the ability to simulate the fine scale nonlinear flow structures and its transient features. While the three-dimensional mountain wave test shows that the model can reproduce the horizontal and vertical propagation of internal gravity waves quite well. Cross-polar flow test demonstrates the rationality of both for the semi-Lagrangian departure point calculation and the discretization of the model near the poles. The real case forecasts reveal that the model has the ability to predict the large-scale weather regimes in summer such as the subtropical high, and to capture the major synoptic patterns in the mid and high latitudes.     

系统寿命分布估计中的模式识别

在由多个指数分布组成的元件系统中,给出系统的分布函数将有助于对系统的寿命特征进行更精细的研究.利用Gibbs抽样法给出了混合指数分布的极大似然估计和最大后验估计.通过引进识别变量,对系统寿命数据进行分类识别,从而更好地监控系统中各元件的工作状况,为系统的可靠运行提供保证.     

数码显微互动网络教室在病理学教学中的应用

实验课是病理学教学的一个重要环节,我院于2006年将数码互动教学模式引入病理学教学,采用多媒体课件、多媒体数码互动系统、病理切片及大体标本观察等手段,发挥教学过程中"教师启发、学生参与、师生互动"的作用,扩展病理学实验的深度和广度,提高实验教学质量。     

单片机课程任务驱动教学模式探讨

本文介绍了目前高校单片机原理课程教学所存在的局限性,传统的教学模式不能发挥学生的学习兴趣,通过完成任务的教学方法,解决学生学习过程中的问题以实现对知识的掌握,意在改进教学模式,促进教学改革,把教学和实践相结合,培养学生创新能力。