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1.
MicroRNAs (miRNAs or miRs) are endogenous non-coding RNAs that negatively regulate gene expres- sion by binding to the 3' non-coding regions of target mRNAs, resulting in their cleavage or blocking their translation. miRNAs may have an impact on cell differentiation, proliferation, and survival, and their deregulation can be inclined to diseases and cancers, including thyroid tumors. The purpose of this review is to summarize the existing findings of deregulated miRNAs in different types of thyroid tumors and to exhibit their potential target genes, especially to demonstrate those involved in tumor invasion and metastasis. In addition, new findings of circulating miRNA expres- sion profiles, single nucleotide polymorphism (SNP) in thyroid tumors, and the correlation of somatic mutations with deregulated miRNA expression in thyroid tumors were all included in this review. 相似文献
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Virus-encoded microRNAs (miRNAs) are a new kind of miRNAs that regulate the expression of target gene in host cells or viruses through inducing cleavage of mRNA, repressing translation, etc., and change the processes of host cells or replicate viruses to escape or resist immune surveillance of host and protect viruses themselves. It has become a hot topic to discover viral genes encoding miRNAs and their target genes, and to identify their functions. This review provides background information on the history of virally encoded miRNAs including their genomic distribution, functions and mechanisms. In addition, we discuss the similarities and differences between virus- and host-encoded miRNAs, the future directions of researches in viral miRNAs and their applications in diseases control and therapy. 相似文献
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A major portion of the mammalian genome is transcribed to produce large numbers of noncoding RNAs(ncRNAs).During the past decade,the discovery of small RNAs,including the microRNAs(miRNA) and small interfering RNAs(siRNA),has led to important advances in biology.The breadth of the ncRNA field of study has substantially expanded and many recent results have revealed a range of functions that can be attributed to the miRNAs and other ncRNAs.For example,H19 RNA,HOTAIR RNA,transcribed ultraconserved regions(T-UCRs),natural antisense RNA,transfer RNA and mitochondrial noncoding RNA have been suggested to play important roles in cancers and other diseases as well as in diverse cellular processes.In this review,we focus on the current status of several classes of ncRNAs associated with cancer with the emphasis on those that are not microRNAs. 相似文献
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Cancer is one of the main causes for death of human beings to date, and cancer biotherapy (mainlyimmunotherapy and gene therapy) has become the most promising approach after surgical therapy, radiotherapy andchemotherapy. However, there are still many limitations on cancer immunotherapy and gene therapy; therefore great ef-fort is being made to develop new strategies. It has been known that, in the process of evolution, a number of genes, theso-called xenogeneic homologous genes, are well-conserved and show the structural and/or functional similarity betweenvarious species to some degree. The nucleotide changes between various xenogeneic homologous genes are derived frommutation, and most of them are neutral mutations. Considering that the subtle differences in xenogeneic homologousgenes can break immune tolerance, enhance the immunogenicity and induce autologous immune response so as to elimi-nate tumor cells, we expect that a strategy of inducing autoimmune response using the property of xenogeneic homologousgenes will become a new therapy for cancer. Moreover, this therapy can also be used in the treatment of other diseases,such as autoimmune diseases and AIDS. This article will discuss the xenogeneic homologous genes, molecular evolutionand cancer therapy. 相似文献
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The research into heavy ion beam biology started in the 1960s, and so far it has become an important interdisciplinary study. Heavy ion beam is more suitable for molecule modification than other sorts of radiation, for it has many superiorities such as the energy transfer effect and the mass deposition effect. Molecule modification with heavy ion beam irradiation can be applied to developing new medicines and their precursors, genetic engineering, protein engi neering, outer space radiobiology, etc. Retrospect and prospect of the research and development of molecule modifica tion with heavy ion beam irradiation are given. 相似文献
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Han Yunxia 《科技信息》2008,(9):142-144
Sex differences are a fundamental fact of human life and it is not surprising to find them reflected in language.It's said that women tend to use more standard forms of English,while men tend to use less standard forms of English.Over the past thirty years,and as a result of the women's movement,gender issues have become entangled with issues of language.Recent research indicates that sex may be more fundamental as an influence on sociolinguistic variation than has been recognized so far.This article will try to discuss the different language use between men and women. 相似文献
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WANGDekai ZHANGHongxin HUGuocheng FUYaping SiHuamin SUNZongxiu 《科学通报(英文版)》2005,50(5):492-494
Mutants are essential genetic muterials to elucidation of biological functions of genes involved.Characterization and isolation of genes in mutants is one of the research tasks in functional genomic era.T-DNA insertional mutagenesis has provided an efficient way to identify genes in plant species.in which the mutated genes could be rapidly isolated once the mutant was confirmed by T-DNA inscrtion. 相似文献
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Through constructing a specialized cDNA library based on small RNAs isolated from partial purified nuclei of Schizosaccharomyces pombe, two novel noncoding RNAs, termed Sp15-70 and Sp18-61, have been identified. Bioinformatics analysis reveals that both the novel RNAs possess a typical secondary structure of box HACA snoRNA and antisense elements to rRNAs. According to the relationship between the structure and function of box HACA snoRNA, Sp15-70 was predicted to direct pseudouridylation in 25S rRNA at U2401 and U2298; Sp18-61 was predicted to direct pseudouridylation in 18S rRNA at U208 and 25S rRNA at U2341. The four predicted pseudouridylation sites were all verified experimentally by the CMC-primer extension analysis. Both Sp15-70 and Sp18-61 were encoded by single copies which were located in the intergenic regions between the CDS of two protein-coding genes on chromosome Ⅰ and Ⅲ of S. pombe, respectively. Putative TATA-like elements can be found upstream from the 5′ end of these snoRNA genes, suggesting that they could be transcribed from their own promoters. Comparison of the two snoRNAs and their functional homologues in diverse organisms reveals that extensive recombinations among different snoRNAs have occurred during the evolution from their primitive progenitors. 相似文献
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All-solid-state lithium-ion batteries are lithiumion batteries with solid-state electrolytes instead of liquid electrolytes.They are hopeful in solving the safety problems of lithium-ion batteries,once their large capacity and long life are achieved,they will have broad application prospects in the field of electric vehicles and large-scale energy storage.The working potential window of solid electrolytes is wider than that of liquid electrolytes,so high-voltage cathode materials could be used in all-solidstate lithium-ion batteries to get higher energy density and larger capacity by elevating the working voltage of the batteries.The spinel LiNi0.5Mn1.5O4material,layered Li–Ni–Co–Mn–O cathode materials and lithium-rich cathode materials can be expected to be applied to all-solid-state lithium-ion batteries as cathode materials due to their highvoltage platforms.In this review,the electrochemical properties and structures of spinel LiNi0.5Mn1.5O4material,layered Li–Ni–Co–Mn–O cathode materials and lithiumrich cathode materials are introduced.More attentions are paid on recent research progress of conductivity and interface stability of these materials,in order to improve their compatibility with solid electrolytes as cathode materials in all-solid-state lithium-ion batteries and fully improve the properties of all-solid-state batteries.Finally,the existing problems of their application in all-solid-state lithium-ion batteries are summarized,the main research directions are put forward and their application prospects in all-solid-state lithium-ion batteries are discussed. 相似文献
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Software-Defined Networking(SDN) has emerged as a promising direction for next-generation network design. Due to its clean-slate and highly flexible design, it is believed to be the foundational principle for designing network architectures and improving their flexibility, resilience, reliability, and security. As the technology matures,research in both industry and academia has designed a considerable number of tools to scale software-defined networks, in preparation for the wide deployment in wide-area networks. In this paper, we survey the mechanisms that can be used to address the scalability issues in software-defined wide-area networks. Starting from a successful distributed system, the Domain Name System, we discuss the essential elements to make a large scale network infrastructure scalable. Then, the existing technologies proposed in the literature are reviewed in three categories: scaling out/up the data plane and scaling the control plane. We conclude with possible research directions towards scaling software-defined wide-area networks. 相似文献
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G-protein coupled recptor(GPCR) is one of the most important protein families for drug target.GPCR agonists and antagonists occupy approximately one third of the world small molecule drug market,Much effort has been invested in GPCR study by both academic institutions and pharmaceutical industries,With seven-transmembrane domains,GPCR plays significant roles in intercellular signal transduction and is involved in a variety of biological pathways.With the availability of sequence data of human and other mammalian genomes,as well as their expressed sequence tag (EST) data,the bioniformatics and genomics approaches can be applied to identifying novel GPCR in the post genomic era .Deorphanizing GPCR or matching ligands with GPCR greatly faciltiates traget validation process and automatically provides a possible compound screening assay ,Similarly,Bioinformatics data mining approach could also be applied to the indentification of GPCR peptided or protein ligands,Here we give a general review of recent advances in the study of GPCR structure,function ,as well as GPCR and ligand identification with the emphasis on the bioinformatics database mining of GPCR and their peptide of protein ligands. 相似文献
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Most of the important agronomic traits in crops,such as yield and quality,are complex traits affected by multiple genes with gene × gene interaction as well as gene × environment interaction.Understanding the genetic architecture of complex traits is a long-term task for quantitative geneticists and plant breeders who wish to design efficient breeding programs.Conventionally,the genetic properties of traits can be revealed by partitioning the total variation into variation components caused by specific genetic effects.With recent advances in molecular genotyping and high-throughput technology,the unraveling of the genetic architecture of complex traits by analyzing quantitative trait locus (QTL) has become possible.The improvement of complex traits has also been achieved by pyramiding individual QTL.In this review,we describe some statistical methods for QTL mapping that can be used to analyze QTL × QTL interaction and QTL × environment interaction,and discuss their applications in crop breeding for complex traits. 相似文献
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宋守信 《河北省科学院学报》1986,(1)
The theoretical research on function-structure relationships of chemicals responsible for carcinogenesis at the very molecular level has begun, so far as Ⅰ know, by Otto Schmidt (1) in the years from 1938 to 1941, with quantum chemistry considerations. This german pioneer author, who was dead probably during the world war Ⅱ, put forth the hypothesis that π. electrons in the polycyclic aromatic hydrocarbons (PAH), in particular their charge density distribution within the molecule, might explain the ir carcinogenic behavior. Since then, many attempts have been made to find correlations between the carcinogenecity of a polycyclic hydrocarbon and certain of its molecular properties. These latter can be obtained by experimental determinations or by quantum chemistry calculations. Correlation research, which is essentially statistical in nature(2), calls for many numerical data to be analyzed. So, quantum chemistry has played and continue to play an important part in this theoretical research, because evaluation of a molecular property of a chemical carcinogen or noncarcinogen by experimental mays takes months, while the attainment of the same measure does not take but only days or even hours. Thus, although reactivity indices of PAH can be determined by exper. imental devices, the famous K- and L-region theory( 3 , 4 ), which is the first successful acquisition in this line, has been built upon analysis of computational data. As K- and L-region theory constitutes a remarkable milestone in the evolution of the theoretical research on chemical carcinogenesis, a brief recall of its essential elements will be given below. 相似文献
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A. M. P. Koskinen 《复旦学报(自然科学版)》2005,44(5):703-704
The rapid development in the genomics and proteomics research has brought about an unprecedented number of potential new drug targets, which translates into an ever-increasing need to rapidly assemble highly pure small molecules (MRS850) with an increased structural complexity 'to identify a small molecule partner for every gene product'. Simultaneously, our increasing awareness of environmental aspects of synthesis places a nearly orthogonal set of requirements for the kinds of syntheses admissible in the future which can be expressed as a rule of 6S' s: selectivity and speed of the syntheses; 相似文献
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Shirley HODGSON 《浙江大学学报(自然科学英文版)》2008,(1):1-4
A small proportion of many cancers are due to inherited mutations in genes, which result in a high risk to the individual of developing specific cancers. There are several classes of genes that may be involved: tumour suppressor genes, oncogenes, genes encoding proteins involved in DNA repair and cell cycle control, and genes involved in stimulating the angiogenic pathway. Alterations in susceptibility to cancer may also be due to variations in genes involved in carcinogen metabolism. This review discusses examples of some of these genes and the associated clinical conditions caused by the inheritance of mutations in such genes. 相似文献
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High-throughput technologies were employed over the past decade to study the expression profiles of cells and tissues.There are large collections of accumulated data from public databases and numerous research articles were published on these data.In the current study,we performed meta-analysis on the gene expression data from human liver and kidney tissues produced from five different technologies:EST,SAGE,MPSS,microarray,and RNA-Seq.We found RNA-Seq was the most sensitive in the number of genes it detected while SAGE and MPSS were the least sensitive.For the genes detected by all the platforms,there were generally good correlations to the measured expression levels of corresponding genes.We further compared detected genes to liver/kidney proteomics data from the Human Protein Atlas,and found 960 of the 8764 genes only detected by RNA-Seq were validated by proteomics results.In conclusion,RNA-Seq is a more sensitive and consistent technology compared to the other four high-throughput platforms,though their results are in general agreement.Average coverage was determined to be the preferred measurement to represent gene expression levels by RNA-Seq data and will be used in future works. 相似文献