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991.
光动力治疗( photodynamic therapy,PDT )是光敏剂在特定波长光源的激发下、在氧分子存在下产生细胞毒性物质的一种治疗方法,主要用于抗肿瘤治疗.目前临床应用的光敏剂对肿瘤细胞的靶向性比较有限,近来的一个热门研究方向是靶向性光敏剂.结合作者多年来在该方向的工作,综合近年来光敏剂研究的发展,比较全面地阐述了带有功能性多肽的靶向性光敏剂及其在光动力治疗中的应用.阐述多肽作为靶向基团的优势,总结了包括透膜多肽、血管靶向多肽、细胞受体靶向多肽等功能多肽与光敏剂偶合物的生物效应,说明了多肽能够实现光敏剂的靶向作用. 相似文献
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993.
Christian Cole Andrew Sobala Cheng Lu Shawn R. Thatcher Andrew Bowman John W.S. Brown Pamela J. Green Geoffrey J. Barton Gyorgy Hutvagner 《RNA (New York, N.Y.)》2009,15(12):2147-2160
Deep sequencing technologies such as Illumina, SOLiD, and 454 platforms have become very powerful tools in discovering and quantifying small RNAs in diverse organisms. Sequencing small RNA fractions always identifies RNAs derived from abundant RNA species such as rRNAs, tRNAs, snRNA, and snoRNA, and they are widely considered to be random degradation products. We carried out bioinformatic analysis of deep sequenced HeLa RNA and after quality filtering, identified highly abundant small RNA fragments, derived from mature tRNAs that are likely produced by specific processing rather than from random degradation. Moreover, we showed that the processing of small RNAs derived from tRNAGln is dependent on Dicer in vivo and that Dicer cleaves the tRNA in vitro. 相似文献
994.
We describe a new DNA sequencing method called sequencing by denaturation (SBD). A Sanger dideoxy sequencing reaction is performed on the templates on a solid surface to generate a ladder of DNA fragments randomly terminated by fluorescently labeled dideoxyribonucleotides. The labeled DNA fragments are sequentially denatured from the templates and the process is monitored by measuring the change in fluorescence intensities from the surface. By analyzing the denaturation profiles, the base sequence of the template can be determined. Using thermodynamic principles, we simulated the denaturation profiles of a series of oligonucleotides ranging from 12 to 32 bases and developed a base-calling algorithm to decode the sequences. These simulations demonstrate that DNA molecules up to 20 bases can be sequenced by SBD. Experimental measurements of the melting profiles of DNA fragments in solution confirm that DNA sequences can be determined by SBD. The potential limitations and advantages of SBD are discussed. With SBD, millions of sequencing reactions can be performed on a small area on a surface in parallel with a very small amount of sequencing reagents. Therefore, DNA sequencing by SBD could potentially result in a significant increase in speed and reduction in cost in large-scale genome resequencing. 相似文献
995.
Victor Guryev 《FEBS letters》2009,583(11):1668-837
Rapid advances in DNA sequencing improve existing techniques and enable new approaches in genetics and functional genomics, bringing about unprecedented coverage, resolution and sensitivity. Enhanced toolsets can facilitate the untangling of connections between genomic variation, environmental factors and phenotypic effects, providing novel opportunities, but may also pose challenges in data interpretation, especially in highly heterogeneous human populations. Laboratory rodent strains, however, offer a variety of tailored model systems with controlled genetic backgrounds, facilitating complex genotype/phenotype relationship studies. In this review we discuss the advent of massively parallel sequencing, its methodological advantage for molecular analysis in model organisms and the expectation of increased understanding of biologically relevant consequences of human genetic variation. 相似文献
996.
Genetic differentiation among Greek lake populations of Carassius gibelio and Cyprinus carpio carpio
The genetic structure of the Western Greece lake populations of Carassius gibelio and Cyprinus carpio carpio populations was characterized by using a PCR-based RFLP and sequencing analysis of mitochondrial rDNA genes and regions (16S
rDNA, cytochrome b and D-loop). Our analysis was able to detect: (a) two haplotypes in C. c. carpio populations and two haplotypes in C. gibelio populations (b) a high nucleotide divergence between the two species and (c) two genetically distinct C. gibelio populations, one existing in the Amvrakia habitat (AMV1) with a second in Ozeros and Trichonida (OZE1 and TRI1) habitat.
The present analysis indicates that genetic diversity observed was limited with a haplotype index between 0.0 and 55.6%, and
a nucleotide diversity within and among populations between 0.0 and 1.27%. It also underlines a restricted mtDNA-based evaluation
of the phylogenetic relationships among C. gibelio and C. c. carpio populations. In addition, the present study contributed knowledge on the genetic variation and structure of these populations
which is absolutely necessary for any efficient fish management and/or conservation programme. 相似文献
997.
Michael Imelfort Chris Duran Jacqueline Batley David Edwards 《Plant biotechnology journal》2009,7(4):312-317
The ongoing revolution in DNA sequencing technology now enables the reading of thousands of millions of nucleotide bases in a single instrument run. However, this data quantity is often compromised by poor confidence in the read quality. The identification of genetic polymorphisms from this data is therefore problematic and, combined with the vast quantity of data, poses a major bioinformatics challenge. However, once these difficulties have been addressed, next-generation sequencing will offer a means to identify and characterize the wealth of genetic polymorphisms underlying the vast phenotypic variation in biological systems. We describe the recent advances in next-generation sequencing technology, together with preliminary approaches that can be applied for single nucleotide polymorphism discovery in plant species. 相似文献
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1000.
抗生素在医疗、畜牧和水产养殖业的大量使用造成了环境中耐药细菌和抗性基因的日益增加,也加速了抗性基因在环境细菌间的传播扩散.本研究以环境样本直接提取的总DNA为模板,运用热不对称交错PCR (thermal asymmetric interlaced PCR, Tail-PCR)技术直接扩增抗生素抗性基因上下游序列.通过优化Tail-PCR反应程序,单循环同时扩增出tetW基因的多条侧翼序列,包括6条上游序列和9条下游序列.基于序列的生物信息学分析发现,上游包括一段反向重复序列和已知的一段tetW调节肽序列以及一个已知的插入序列,下游包括一个保守的未知序列和一个开放式阅读框架(the open reading frame,ORF)编码甲基转移酶.结果不仅发现了可能协助tetW基因传播的功能元件,也提供了一个未知侧翼序列高效和便捷的研究方法,即采用Tail-PCR技术,一组样品即能便捷获得多条侧翼序列. 相似文献