Stable transformation of maize after gene transfer by electroporation

The graminaceous monocots, including the economically important cereals, seem to be refractory to infection by Agrobacterium tumefaciens, a natural gene transfer system that has been successfully exploited for transferring foreign genes into higher plants. Therefore, direct transfer techniques that are potentially applicable to all plant species have been developed using a few dicot and monocot species as model systems. One of these techniques, electroporation, uses electrical pulses of high field strength to permeabilize cell membranes reversibly so as to facilitate the transfer of DNA into cells. Electroporation-mediated gene transfer has resulted in stably transformed animal cells and transient gene expression in monocot and dicot plant cells. Here we report that electroporation-mediated DNA transfer of a chimaeric gene encoding neomycin phosphotransferase results in stably transformed maize cells that are resistant to kanamycin.     

HMW glutenin subunits in multiploidAegilops species: composition analysis and molecular cloning of coding sequences

The Aegilops genus contains species closely related to wheat. In common with wheat, Aegilops species accumulate high molecular weight (HMW) glutenin subunits in their endospermic tissue. In this study, we investigated the composition of HMW glutenin subunits in four multiploid Aegilops species using SDS-PAGE analysis. Furthermore, by working with Ae. ventricosa, we established an efficient genomic PCR condition for simultaneous amplification of DNA sequences coding for either x- or y-type HMW glutenin subunits from polyploid Aegilops species. Using the genomic PCR condition, we amplified and subsequently cloned two DNA fragments that may code for HMW glutenin subunits in Ae. ventricosa. Based on an analysis of the deduced amino acid sequences, we concluded that the two cloned sequences encode one x- and one y-type of HMW glutenin subunit, respectively.     

高性能活性炭制备技术新进展

根据活性炭制备过程的特点,概述了活性炭制备前期、中期、后期过程中的主要制备技术,比较了不同制备阶段不同制备技术的特点,为制备高性能活性炭及其应用提供了参考.     

非晶CoZrNb磁性薄膜的研究

研究溅射条件和旋转磁场热处理对CoZrNb薄膜结构和性能的影响。结果表明,高的溅射功率和合适的氩气压强对非晶CoZrNb薄膜的形成有用,并且这些薄膜的矫顽力较小。旋转磁场热处理将改善薄膜的软磁性能,使得矫顽力进一步减小。对溅射条件对薄膜性能的影响机制和旋转磁场热处理改善薄膜性能的机制作了简要的讨论。     

钨铜复合材料的制备技术

随着电器及电子等行业迅猛发展,钨铜材料的需求量越来越大。文章讨论了钨铜复合材料的常规制备技术,如熔渗法的基本过程以及对材料显微组织、致密度、力学性能以及导电性能等方面的影响;并分别从钨铜纳米粉末的制备、高速、高效粉末压制、快速粉末烧结三个方面展望了钨铜复合材料制备技术的未来发展方向。     

白菜类作物转基因技术研究进展

白菜类作物是芸薹属中重要的栽培亚种群,也是重要的蔬菜之一。建立高效可重复的植株再生和遗传转化体系是利用基因工程进行遗传改良所必需的。本文从高频率植株再生体系的建立,ＤＮＡ直接转移,不依赖于植物细胞或组织培养的农杆菌介导转移,建立在细胞或组织培养基础上的农杆菌介导的转化,转化株后代的遗传行为等方面论述了白菜类作物转基因技术的最新研究进展,并提出了存在的问题和进一步的研究方向。     

甜菜高分子量核DNA的分离

研究了从甜菜中分离高分子量核DNA的方法．利用离心分离细胞核，经低融点琼脂糖块包埋、蛋白酶K原位裂解，结合低融点琼脂糖脉冲电泳去除淀粉制备高分子量核DNA．结果表明利用幼叶制备高分子量核DNA分子量高，更容易去除其中的淀粉；并且利用该方法得到的高分子量核DNA纯度高，适于部分酶切．     

DNA分子标记技术在中草药鉴别中的应用

DNA分子标记技术以其特异性强、可靠性好、灵敏度高等特点为中草药鉴别开辟了新的道路．RFLP,RAPD,AFLP,DNA序列分析等DNA分子标记技术已经在该领域被广泛研究,并且取得了可喜的成绩．介绍了这几种技术的原理和特点,概括了近年来的应用进展,并对前景进行了展望．     

转基因玉米遗传转化的研究进展

转基因玉米是目前植物基因工程的研究热点之一,已有转基因抗虫玉米、抗除草剂玉米进入商品化生产。通过对转基因玉米遗传转化方法的研究,概括了目前在转基因玉米的遗传转化中所用的各种方法、及其优缺点,以及已取得的成果和遗传转化的检测分析方法的研究进展。     

废植物炭制活性炭的研究

研究废植物炭制活性炭的可行性及效果,探讨了以水蒸汽为活化介质时活化工艺条件对活性炭吸附性能的影响,确定了最佳活化工艺条件,并对活性炭的孔结构进行了分析探讨。结果表明,利用废植物炭制活性炭是可行的,得到的活性炭具有较高的吸附性能和丰富结构。废植物炭的种类和灰发含量决定其活性炭的吸附性能。活化后活性炭表面积的增加主要源于其微孔表面积的增加。     

非压缩域内视频分割算法研究

视频分割是多媒体数据检索的关键技术之一.近年来在视频分割领域出现了大量算法,这些算法总体上来说可以分为压缩域和非压缩域两类.本文主要讨论了几种基于非压缩域的视频分割算法.     

玉米面粘合剂的制备及粘度稳定性研究

本文介绍了制备玉米面粘合剂的过程,着重研究了影响该粘合剂粘度及稳定性的各种因素,提出了影响粘度特性的主要因素,找到了适宜的工艺条件。     

叶绿体DNA分析技术及其在植物系统学研究中的应用

叶绿体DNA在植物系统学研究中已得到广泛应用。综述了DNA杂交、DNA限制酶谱分析、RFLP分析、PCR_RFLP分析、微卫星序列分析、SSCP分析和核酸序列分析等叶绿体DNA分析技术的原理、特点及应用     

ZnO基透明导电薄膜制备方法研究进展

ZnO基透明导电薄膜与掺锡氧化铟薄膜（ITO）相比,不仅性能与其相似,还具有ITO很多无法比拟的优点．因此,制备ZnO基透明导电薄膜成为当今研究热点．综述了ZnO基透明导电薄膜制备方法的研究进展,并对各自的优缺点进行了讨论．     

Simulation of ChIP-Seq based on extra-sonication of IPed DNA fragments

The combination of chromatin immunoprecipitation with sequencing (ChIP-Seq) is an effective method for obtaining an in vivo genome-wide profile of the interaction of a protein with DNA. With the dramatic development of high-throughput short sequencing technologies, several new algorithms have been developed to process ChIP-Seq. However, the reported analytical tools for ChIP-Seq based on size selection of immunoprecipitated (IPed) DNA fragments are mainly adopted on the Solexa system. As a sequencer with the highest throughput, few studies of ChIP-Seq based on SOLiD system have been reported. The main difference of the SOLiD and Solexa systems exists in the length of DNA fragments during preparing sequencing libraries. The SOLiD system has relatively short DNA fragments if it processes a further sonication of IPed DNA fragments in order to meet the length requirement of DNA frag-ments for emulsion-PCR (ePCR). This work aims to investigate the influences of DNA fragment length on data analysis from ChIP-Seq. Previous studies show that typical bimodal peaks can be observed in Solexa ChIP-Seq data, but based on the analysis of the real SOLiD ChIP-Seq data in this study, we found that there were no double peaks with apparent reads shift in a local enriched region and the local reads distribution of peaks were tested by normal distribution. Using real and simulated ChIP-Seq data, three main ChIP-Seq algorithms (CisGenome, SISSRs and MACS) have been investigated. We found that algorithms developed for processing ChIP-Seq data generated from Solexa library protocol, cannot efficiently capture the feature of the ChIP-Seq data from SOLiD library. Misuse of those analytical tools would be a possible reason for failure of ChIP-Seq on the SOLiD system. Therefore, a new ChIP-Seq analytical strategy for an extra-sonication of IPed DNA fragments needs to be developed.     

非压缩域内视频分割算法研究

视频分割是多媒体数据检索的关键技术之一。近年来在视频分割领域出现了大量算法，这些算法总体上来说可以分为压缩域和非压缩域两类。本文主要讨论了几种基于非压缩域的视频分割算法。     

植物Cot—1DNA的快速制备方法

Ｃｏｔ－１ＤＮＡ富含高度和中度重复序列,能封阻ＹＡＣ和ＢＡＣ中的重复序列,从而促进了大片段ＤＮＡ在原位杂交技术（ＩＳＨ）中的应用。植物Ｃｏｔ－１ＤＮＡ尚未商品化,本文介绍了一种简捷的快速制备植物Ｃｏｔ－１ＤＮＡ的方法。     

山羊草四个组高分子量麦谷蛋白亚基组成分析

利用SDS-PAGE技术对山羊草属18个种的46份材料进行高分子谷蛋白亚基电泳分析．18个种各电泳出2～5条带，共有24种不同的电泳条带，26种不同的麦谷蛋白亚基类型，每个种有1～3种类型．山羊草与小麦的麦谷蛋白亚基存在着较大的差异，山羊草属中各种间在高分子量麦谷蛋白亚基组成与其亚基的电泳迁移率方面也存在广泛差异．     

一种苦丁茶含片的制备方法

本文阐述了一种苦丁茶含片的制备方法。以苦丁茶为主要原料,薄荷为辅料,探索了苦丁茶含片的制备工艺。该工艺应用常温下保鲜浓缩干燥技术及科学配方确定:将茶叶的浸提液用70%的乙醇将其大分子物质提取出来,取上清液并将其浓缩,然后向其浓缩液中加入一定比例的薄荷浓缩液,并向该混合液中加入一定量的赋形剂,最后造型并(且)放入烘箱中烘烤,取出即是具有润喉效果的苦丁茶含片。该含片不改变苦丁茶药效成分,在水中分布迅速均匀,有效成分便于吸收,药性利用高,质地酥脆,口感舒适,停用方便,兼具固体制剂和液体的特点,在食品行业具有广阔的市场前景。