离体诱导单倍体在植物遗传与育种中的应用

单倍体量种特殊的生命现象,涉及到生物的起源,进化 ,胚胎发生与遗传变异等学科,受到科学家的关注。本文讨论下述问题：１）高等植物单倍体的起源;２）单倍体的遗传学;３）离体诱导单倍体的应用。     

RAPD技术在生物学研究中的应用

ＲＡＰＤ标记具有简易,快速,灵敏,经济的优点,本文介绍了该技术在生物物种鉴别,遗传多样性,基因定位,分子连锁图谱构建和外源导入基因的分子检测等生物学领域广泛应用的概况。由ＲＡＰＤ转化而来的ＲＡＰＤ－ＰＣＲ－ＳＣＡＲ标记稳定,灵敏,准确性高,在种质资源鉴别,分子标记辅助育种中有着潜在的应用前景。     

聚乳酸及其复合材料在生物医药中的应用研究

本文综述了聚乳酸作为药物缓控释载体材料、组织工程支架材料和医用敷料的研究进展;介绍了聚乳酸．聚乙醇酸、聚乳酸,磷酸钙等复合材料在生物医药中的应用。     

离子浓差极化效应及其在微纳流控分子富集系统中的应用进展

离子选择性输运导致的离子浓差极化(ion concentration polarization, ICP)现象与微纳流控技术的结合为生物分子检测、离子分离和海水淡化等许多领域问题提供了新的解决方案,也为传统ICP问题的研究提供了新的技术平台.本文首先对ICP现象做简要介绍,对理论和仿真方面的最新研究成果进行梳理,重点介绍第二类电渗流的产生机理及其对超限定电流的决定作用.然后,对微纳通道系统,特别是哑铃型和H型微纳通道系统中的ICP现象进行解释,对基于ICP效应的带电分子富集、海水脱盐、整流等应用系统进行概述,着重介绍带电分子富集方面最新的仿真研究成果.     

支持向量机及其在机械故障诊断中的应用研究

针对支持向量机分类算法中模型选择对分类精确性影响很大的问题,结合转子实验台模拟的典型旋转机械故障数据对影响多故障分类器分类性能的相关因素进行了研究。结果表明,在少量时域故障数据样本条件下,选用不同的核函数及核函数参数对多故障分类器的分类精度有一定影响,为实际工程应用中选择合适的支持向量机核函数类型及其参数提供一定的帮助.     

淀粉的改性及其在可降解塑料和橡胶中的应用研究

淀粉作为一种天然高分子,由于其价格低,可再生,生物降解性好等优点,在材料制备与改性方面得到了人们的青睐.同时由于淀粉所固有的亲水性,难于加工性以及和石化材料间较差的相容性等也大大限制了其在非食品工业中的应用范围.本文介绍了国内外淀粉改性的最新进展及其尝试其在可降解塑料和橡胶方面的应用研究,并就目前该领域存在的一些问题作了初步探讨.     

自组织临界性及其在斜坡重力作用灾害研究中的应用

首先介绍了3种在自组织作用下的反映斜坡物质能量耗散普适性过程的沙堆模型实验, 以及托卡马克等离子体试验. 实验表明, 当沙堆由非均匀颗粒组成时呈现SOC现象; 托卡马克等离子体当约束条件减弱时具有SOC的一些特性. 然后通过沙石材料土工性质的测试和堆积结构模拟分析, 得出SOC主要由系统的组构特征确定的结论. 最后在SOC的概念框架下讨论了斜坡重力作用灾害的机理研究、预测预报以及防治工程设计等问题.     

具有重要生理活性寡糖的发现及其应用

发明了合成1－3主链连接带有1－6侧链和1－6主链连接带有1－3侧链连接的葡萄寡糖的简易方法。可以大量制备可激活植物的自我防卫系统的葡聚六糖,在世界上首次合成了香菇多糖的核心结构片段寡糖,发现它们激活动物免疫的能力优于现用的国产香菇多糖,正在将这两类寡糖分别作为无公害绿色农药和国家一类抗肿瘤新药而加以开发。     

分子生物学技术在环境微生物研究中的应用

随分子生物学和遗传工程技术的迅速发展，已存在对微生物进行遗传操作而促进微生物在环境生物技术中的应用。本文较系统地概述了与环境微生物密切相关的分子生物学技术，如核酸探针检测技术，利用引物的PCR技术，基因重组技术，基因芯片技术，以及这些相关技术在环境监测、环境污染的防治和环境基因工程菌的稳定性和安全性评估中的应用。结果表明，分子生物学技术在研究环境微生物中发挥了重要的作用。     

Genetic determinants of neuronal vulnerability to apoptosis

Apoptosis is a common mode of cell death that contributes to neuronal loss associated with neurodegeneration. Single-nucleotide polymorphisms (SNPs) in chromosomal DNA are contributing factors dictating natural susceptibility of humans to disease. Here, the most common SNPs affecting neuronal vulnerability to apoptosis are reviewed in the context of neurological disorders. Polymorphic variants in genes encoding apoptotic proteins, either from the extrinsic (FAS, TNF-α, CASP8) or the intrinsic (BAX, BCL2, CASP3, CASP9) pathways could be highly valuable in the diagnosis of neurodegenerative diseases and stroke. Interestingly, the Arg72Pro SNP in TP53, the gene encoding tumor suppressor p53, was recently revealed a biomarker of poor prognosis in stroke due to its ability to modulate neuronal apoptotic death. Search for new SNPs responsible for genetic variability to apoptosis will ensure the implementation of novel diagnostic and prognostic tools, as well as therapeutic strategies against neurological diseases.     

Evolution Made to Order: Plant Breeding and Technological Innovation in Twentieth-Century America

The last charcoal iron blast furnace in the United States shut down in 1945. The most obvious reason for the extraordinary longevity of this industry was the almost unlimited supply of virgin timber in the United States. Although an obvious explanation, it is deceptive. The much more crucial reason for the longevity of the American charcoal iron industry was the technical difficulties involved in adapting coke- and coal-smelted iron to existing industrial processes. Until these technological problems could be overcome, charcoal iron was able to preserve a place for itself in the industrial environment of the late 19th and early 20th centuries. By concentrating their attention on the rapid advance of coke-smelted iron from 1870 onward, historians of the American iron industry have neglected this ability of the older iron technology to adapt to the new industrial conditions.     

混合量子遗传算法在软硬件协同综合中的应用研究

针对多处理器嵌入式系统,结合拟 Newton算法,提出了混合量子遗传算法(MQGA)在系统设计中的解决方案,并引入了模拟退火技术.实验结果表明,MQGA能有效解决软硬件划分问题,提高了求解质量和算法的收敛速度,降低了计算代价,保证了算法的自适应性和全局最优性     

小麦转基因研究现状及展望

自二十世纪八十年代开始研究转基因植物以来,小麦作为世界主要粮食来源,其转基因遗传改良受到科学家的广泛关注。目前国内外已有近200例外源基因,主要是抗除草剂类基因、抗病虫基因、品质基因、抗旱耐盐等抗逆基因、雄性不育类基因等,通过基因枪法、农杆菌介导法、花粉管通道法等技术转入小麦的报道。从转单基因到进行多基因组装,从改良各种生物胁迫和非生物胁迫的抗逆性,到改良品质、高产等生理和农艺性状,是未来转基因小麦的研究方向。本文就近二十几年来转基因小麦研究进展及存在问题进行了全面系统的综述和探讨。     

Molecular and engineering approaches to regenerate and repair teeth in mammals

Continuous replacement of teeth throughout the lifespan of an individual is possibly basal for most of the vertebrates including fish and reptiles; however, mammals generally have a limited capacity of tooth renewal. The ability to induce cellular differentiation in adults to replace lost or damaged cells in mammals, or to tissue-engineer organs in vitro, has hence become one of the major goals of regenerative medicine. In this article, we will revisit some of the important signals and tissue interactions that regulate mammalian tooth development, and will offer a synopsis of the latest progress in tooth regeneration and repair via molecular and engineering approaches. It is hoped that this article will not only offer an overview of recent technologies in tooth regeneration and repair but will also stimulate more interdisciplinary research in this field to turn the pursuit of tooth regeneration and repair into practical reality.     

Genetic and molecular approaches to synthesis and action of the yeast killer toxin

Summary The K1 killer toxin ofSaccharomyces cerevisiae is a secreted, virally-coded protein lethal to sensitive yeasts. Killer yeasts are immune to the toxin they produce. This killer system has been extensively examined from genetic and molecular perspectives. Here we review the biology of killer yeasts, and examine the synthesis and action of the protein toxin and the immunity component. We summarise the structure of the toxin precursor gene and its protein products, outline the proteolytic processing of the toxin subunits from the precursor, and their passage through the yeast secretory pathway. We then discuss the mode of action of the toxin, its lectin-like interaction with a cell wall glucan, and its probable role in forming channels in the yeast plasma membrane. In addition we describe models of how a toxin precursor species functions as the immunity component, probably by interfering with channel formation. We conclude with a review of the functional domains of the toxin structural gene as determined by site-directed mutagenesis. This work has identified regions associated with glucan binding, toxin activity, and immunity.