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971.
972.
为准确编辑生物信息学稿件,对目前科技期刊生物信息学稿件中最常见的一些既有关联又有区别的名词用法错误进行了辨析。结果表明:生物信息学稿件中常见的基因、蛋白质、核苷酸序列、氨基酸序列、同源性、亲缘关系等名词的使用及其表述经常有误甚至有歧义;同时对基因和蛋白质的符号表达错误进行了辨析,虽然有90%的科技期刊中基因符号已用斜体字母表达,但其中还是有很多基因符号尤其以基因命名的引物名称以及重组质粒中的基因符号未能用斜体字母表达。该研究结果可为科技期刊编辑掌握生物信息学稿件中最基本的一些名词的使用及其表述提供参考。 相似文献
973.
人心肌钙蛋白T(cardiac troponin T,cTnT)可调节肌丝蛋白的Ca2 浓度,从而调节心脏肌肉收缩的肌钙蛋白复合体组成成分之一.在心力衰竭末期,cTnT再度表达.cTnT的mR-NA水平和其蛋白水平升高与心力衰竭密切相关.从正常流产胎儿心脏提取RNA,通过反转录获得cDNA,再利用PCR方法得到目的基因.序列分析证实,得到的基因是正确而特异的cTnT基因,不同人种的cTnT序列同源性很高,达99%以上.全序列有3个碱基与国外报道序列有差别,所编码氨基酸有2个不同.推测其区别可能是人种的差异或胎儿与成人发育期不同造成的. 相似文献
974.
优化吹灰经济性和洁净因子下限选取的研究 总被引:2,自引:0,他引:2
根据我国目前大型电厂采用的传统吹灰方式,比较吹灰前后的主要运行参数变化,利用等效焓降法计算其带来的煤耗量变化,得出除灰给锅炉机组带来的经济性存在的一定缺点,为了进一步提高经济性,提出了一种通过实时监测和确定洁净因子下限来进行吹灰的方法. 相似文献
975.
Modelling and Trading the Greek Stock Market with Gene Expression and Genetic Programing Algorithms 下载免费PDF全文
Andreas Karatahansopoulos Georgios Sermpinis Jason Laws Christian Dunis 《Journal of forecasting》2014,33(8):596-610
This paper presents an application of the gene expression programming (GEP) and integrated genetic programming (GP) algorithms to the modelling of ASE 20 Greek index. GEP and GP are robust evolutionary algorithms that evolve computer programs in the form of mathematical expressions, decision trees or logical expressions. The results indicate that GEP and GP produce significant trading performance when applied to ASE 20 and outperform the well‐known existing methods. The trading performance of the derived models is further enhanced by applying a leverage filter. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
976.
Despite the current availability of several hundreds of thousands of amino acid sequences, more than 39% of the well-defined
enzyme activities (EC numbers) are not associated with any sequence in major public databases. This wide gap separating knowledge
of biochemical function and sequence information is found in nearly all classes of enzymes. Thus, there is an urgent need
to explore the 1525 orphan enzymes (EC numbers without associated sequences), in order to progressively bridge this unwanted
gap. Improving genome annotation could unveil a significant proportion of sequenceless enzymes. Peptide mass mapping and further
genome mining would be useful to identify proper sequence for enzymes found in species for which genetic tools are missing.
Finally, the whole community must help major public databases to begin addressing the problem of missing or incomplete information.
Received 31 October 2005; received after revision 8 December 2005; accepted 20 December 2005 相似文献
977.
Glucocorticoids in T cell apoptosis and function 总被引:5,自引:0,他引:5
Glucocorticoids (GCs) are a class of steroid hormones which regulate a variety of essential biological functions. The profound
anti-inflammatory and immunosuppressive activity of synthetic GCs, combined with their power to induce lymphocyte apoptosis
place them among the most commonly prescribed drugs worldwide. Endogenous GCs also exert a wide range of immunomodulatory
activities, including the control of T cell homeostasis. Most, if not all of these effects are mediated through the glucocorticoid
receptor, a member of the nuclear receptor superfamily. However, the signaling pathways and their cell type specificity remain
poorly defined. In this review, we summarize our present knowledge on GC action, the mechanisms employed to induce apoptosis
and the currently discussed models of how they may participate in thymocyte development. Although our knowledge in this field
has substantially increased during recent years, we are still far from a comprehensive picture of the role that GCs play in
T lymphocytes.
Received 20 August 2005; received after revision 27 September 2005; accepted 10 October 2005 相似文献
978.
Polyphenolic phytochemicals are ubiquitous in plants, in which they function in various protective roles. A ‘recommended’
human diet contains significant quantities of polyphenolics, as they have long been assumed to be ‘antioxidants’ that scavenge
excessive, damaging, free radicals arising from normal metabolic processes. There is recent evidence that polyphenolics also
have ‘indirect’ antioxidant effects through induction of endogenous protective enzymes. There is also increasing evidence
for many potential benefits through polyphenolic-mediated regulation of cellular processes such as inflammation. Inductive
or signalling effects may occur at concentrations much lower than required for effective radical scavenging. Over the last
2 – 3 years, there have been many exciting new developments in the elucidation of the in vivo mechanisms of the health benefits of polyphenolics. We summarise the current knowledge of the intake, bio-availability and
metabolism of polyphenolics, their antioxidant effects, regulatory effects on signalling pathways, neuro-protective effects
and regulatory effects on energy metabolism and gut health.
Received 14 May 2007; received after revision 27 June 2007; accepted 24 July 2007 相似文献
979.
Purine and pyrimidine receptors 总被引:17,自引:0,他引:17
Burnstock G 《Cellular and molecular life sciences : CMLS》2007,64(12):1471-1483
Adenosine 5′-triphosphate (ATP), in addition to its intracellular roles, acts as an extracellular signalling molecule via
a rich array of receptors, which have been cloned and characterised. P1 receptors are selective for adenosine, a breakdown
product of ATP, produced after degradation by ectonucleotidases. Four subtypes have been identified, A1, A2A, A2B and A3 receptors. P2 receptors are activated by purines and some subtypes also by pyrimidines. P2X receptors are ligand-gated ion
channel receptors and seven subunits have been identified, which form both homomultimers and heteromultimers. P2Y receptors
are G protein-coupled receptors, and eight subtypes have been cloned and characterised to date.
Received 22 November 2006; received after revision 11 January 2007; accepted 27 February 2007 相似文献
980.
Garbern JY 《Cellular and molecular life sciences : CMLS》2007,64(1):50-65
Pelizaeus-Merzbacher disease (PMD) and the allelic spastic paraplegia type 2 (SPG2) arise from mutations in the X-linked gene
encoding myelin proteolipid protein (PLP). Analysis of mutations affecting PLP, the major protein in central nervous system
myelin, has revealed previously unsuspected roles for myelinating glia in maintaining the integrity of the nervous system.
The disease spectrum for PMD and SPG2 is extraordinarily broad and can be best understood by accounting not only for the wide
range of mutations that can occur but also for the effects of PLP1 mutations on both cell autonomous and non-cell autonomous processes in myelinating cells. Appreciating the wide range of
genetic and cellular effects of PLP1 mutations is important for patient and family counseling, understanding disease pathogenesis, and, ultimately, for developing
future disease-specific therapies.
Received 24 April 2006; received after revision 3 July 2006; accepted 9 October 2006 相似文献