Study of Cellular Experiment of Electric Pulse Imposed on Cancer Cell

The objective of the study is the cytocidal and inhibitory effect of energy-controllable pulse on ovarian cancer cell line SKOV3.Ovarian cancer cell suspension were treated by electric pulse with different parameters,.The inhibitory rate(IR) was assayed by modified colorimetric MTT methods,the growth curves of two test groups and one control group were also measured.and the ultrasturctureal changes were observed under electron microscopy(EM) and scan electron microscopy (SEM),It was found that the treated SKOV3 cell proliferated more slowly.IR was increased with the enhancement of pulse paramters,The ultrastructural study showed that morphological changes occured obviously.Swollen mitochondria,fracutured ridges,cytoplasmic vacuoles and membrane holes appeard in most of the processed cells,and a part of bilayer membrane was ruptured.It is indicated that irreversible electric breakdown occurred in some of the treated cells,and the electric pulse could kill cancer cell and inhibit its recovery and growth.     

Framing Effects of News Coverage of the Embryonic Stem Cell Controversy: Issue Involvement as an Effects Moderator

This study examines reactions to ethical and strategic framing in the news coverage of the embryonic stem cell research controversy, depending on the level of issue involvement. In order to test hypotheses regarding the effects of strategic vs. ethical frames and the moderating role played by issue involvement, an online experiment was conducted. Results indicated that these two frames interacted with issue involvement and generated different reactions among participants.     

成年大鼠心肌细胞分离方法

目的：探讨三种分离成年大鼠心肌细胞的方法。方法：分别应用酶消化法（0．1％的胰蛋白酶和0．1%胶原酶依次消化）、程序冷冻后机械分离法（4℃30min，-20℃30min，-80℃30min，-196℃冻存）、酒精和多聚甲醛固定后机械分离法分离心肌组织获取单个心肌细胞悬液。光镜观察，结合形态学和台盼蓝染色评价心肌细胞。结果：用三种方法新分离的活性心肌细胞比率约70%～80%、杆状、横纹清晰。结论：三种方法均可以对成年大鼠心肌细胞进行良好的分离。     

The “Mere Presence” Hypothesis: Investigating the Nonverbal Effects of Cell-Phone Presence on Conversation Satisfaction

Prior research has supported the mere presence hypothesis, which suggests that cell phones act as an environmental nuisance that negatively impact the quality of face-to-face interactions. This study conducted an experiment to determine whether cell-phone presence negatively influences conversation satisfaction. Specifically, network member dyads (N = 46) engaged in unstructured conversations where one partner’s cell phone was either absent or present. The results revealed that, whereas the mere presence of a cell phone did not influence conversation satisfaction, individuals’ recollection of whether or not a cell phone was present did significantly negatively impact their pre- to posttest reports of conversation satisfaction. Implications of these findings for research on the mere presence hypothesis as well as directions for future research are discussed.     

《Cell》的编辑出版特色

通过对《Cell》的审稿原则及标准、栏目设置、编审体制等方面的探讨来认识《Cell》的编辑出版特色。     

生物工程在农业资源开发中的应用

生物工程是对未来具有重要影响的高新技术领域之一,广泛应用于化工、食品、医药、农业、环境、材料等行业。本文介绍了生物工程在国内外发展状况及其对人类的重要影响,比较详细地论述了基因工程、细胞工程、发酵工程以及酶工程等生物工程在农业资源开发中的应用。基因工程突破了传统的农业生产模式,利用全新方法培育出具有物种性能的新型作物和牲畜品种,使农业产生一次新的革命;细胞工程不仅通过细胞融合产生优良杂种,而且使工厂化快速育苗成为可能;发酵工程对于生态农业和绿色农业的形成都有重要作用;而酵工程是农副产品精加工、深加工、发展高效益农业不可缺少的技术手段。生物工程在农业资源开发中的广泛应用,可使我国资源得到更合理、更有效、更高层次的开发利用,使我国农业生产达到一个新水平。     

学习元平台的语义技术架构及其应用

语义Web强调对网络资源附加可供机器理解和处理的语义信息,使人与电脑之间更好地协同工作,同时也使资源的大规模重用和自动化处理成为可能。近年来,随着语Y,．Web技术的不断发展,各种e—Learning平台（适应性学习系统、智能导师系统、语义化知识社区等）纷纷尝试引入语义技术,为用户提供更加个性化和智能化的学习服务。学习元平台（LCS）基于语义化组织的学习资源,应用语义Web体系框架中的本体技术和推理技术,构建了包含OntologyAPI层、语义层、标注层和推理层的语义技术框架。依托该框架,LCS分别在学习资源的有序进化控制、学习资源的动态语义关联、学习资源的动态语义聚合、学习资源的适应性推荐、学习资源的语义化检索以及社会认知网络的动态构建等方面进行探索性研究,实现从资源的语义化组织到具有更强智能性和个性化的高级应用服务。这些应用实践表明,将语义技术在e-Learning系统中推广应用,需要积极引入外部开放、成熟的本体和更多高级应用服务,集成具有较强针对性和运行效率的推理机,在人工标注和自动标注相结合的基础上,关注资源和用户的语义化表征,重视情境模型的设计和情境本体的构建。     

激素对白灵菇菌丝生长影响的研究

不同的激素及其组合对白灵菇茁丝生长的影响不同。利用激素提高白灵菇茁丝胞外酶的活力，促进其生长发育。激素处理能明显缩短白灵菇的发菌时间。     

Accumulation and ultrastructural distribution of copper in Elsholtzia splendens

Copper accumulation and intracellular distribution in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species, was investigated by transmission electron microscope (TEM) and gradient centrifugation techniques.Copper concentrations in roots, stems and leaves of E. splendens increased with increasing Cu levels in solution. After exposure to 500 μmol/L Cu for 8 d, about 1000 mg/kg Cu were accumulated in the stem and 250 mg/kg Cu in the leaf of E. splendens. At 50μmol/L Cu, no significant toxicity was observed in the chloroplast and mitochondrion within its leaf cells, but separation appeared at the cytoplasm and the cell wall within the root cells. At ＞250 μmol/L Cu, both root and leaf organelles in E. splendens were damaged heavily by excessive Cu in vivo. Copper subcellular localization in the plant leaf after 8 days' exposure to 500 μmol/L Cu using gradient centrifugation techniques was found to be decreased in the order: chloroplast＞cell wall＞soluble fraction＞other organelles. The plant root cell wall was found to be the site of highest Cu localization. Increase of Cu exposure time from 8 d to 16d, increased slightly Cu concentration in cell wall fraction in roots and leaves, while that in the chloroplast fraction decreased in leaves of the plants grown in both 0.25 μmol/L and 500 μmol/L Cu. TEM confirmed that much more Cu localized in cell walls of E. splendens roots and leaves, but also more Cu localized in E. splendens' chloroplast when the plant is exposed to Cu levels＞250μmol/L, as compared to those in the plant grown in 0.25 μmol/L Cu. Copper treatment at levels＞250 μmol/L caused pronounced damage in the leaf chloroplast and root organelles. Copper localization in cell walls and chloroplasts could mainly account for the high detoxification of Cu in E. splendens.     

Research on a simulated 60 kW PEMFC cogeneration system for domestic application

INTRODUCTION Distributed cogeneration technology is a hot topic in electrical and energy industries (Ferguson and Ugursal, 2004). China’s need to limit the power usage in some places to meet the peak power demand in summer of recent years stimulated and supported increasing research on distributed generation tech- nologies. Fuel cells, as renewable energy sources, are considered one of the most promising sources of distributed electrical power. Operational fuel cell systems have perform…