沈从文的时间意识     

覃新菊 《信阳师范学院学报(哲学社会科学版)》2006,26(6):1-5

沈从文的时间意识与死亡意识相生相成,构成沈从文“生命哲学”的重要而又特殊的组成部分。他认为时间的魔力巨大,能消融生命,能治疗痛苦,还能造就创作;他的时间意识停留在“过去”,具有“过去式”、“静态化”与“突变性”的特点。  相似文献   

人工诱变在植物病原真菌研究中的应用     

王欣丽  朱飞 《临沂师范学院学报》2007,29(6):62-66

分别介绍了物理诱变、化学诱变和插入突变在病原真菌遗传变异规律和致病机理研究中的应用.  相似文献   

求解0/1背包问题的烟花算法研究     

张家琴 《武汉工程职业技术学院学报》2011,(3):64-66

0/1背包问题是一个典型的NP难题,具有重要的理论研究价值,也具有广泛的应用基础。借鉴北京大学关于烟花算法的新近成果,尝试考虑二者的结合,初步设计并实现了求解0/1背包问题的烟花算法,开展了较为充分的实验,并作了相关分析与探讨。  相似文献   

带有倒位变异的差分进化算法     

翟志波  李会荣  江巧永  高岳林 《商洛学院学报》2011,25(2)

针对高维复杂函数的优化问题,提出一种带有倒位变异的差分进化算法.当个体适应度值连续几代不变时,对前一代的最优个体进行倒位变异,以增强种群的多样性,使其跳出局部最优.数值实验结果表明:该算法全局搜索能力强,收敛速度快,且鲁棒性好.  相似文献   

生物变异的机制     

张爱民 《济宁师范专科学校学报》2007,28(6):19-20

本文详细介绍了生物的变异及其机制.生物的变异包括遗传变异和不遗传变异,遗传变异是由于遗传物质的变化而引起的.在细胞分裂的过程中,遗传物质发生重组产生变异;另外,生物体内外因素会影响遗传物质发生改变,从而产生变异.  相似文献   

A deep vein thrombosis caused by 20209C>T mutation in homozygosis of the prothrombin gene in a Caucasian patient     

Silvia Izquierdo álvarez  Eva Barrio Ollero  Francisco Miguel Llinares Sanjuan  Fabiola Lorente Martínez  María Teresa Calvo Martín 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2014,24(1):159-166

Introduction:

Additional nucleotide substitutions in the 3′-untranslated region of prothrombin gene could explain some thrombotic events and also adverse pregnancy outcomes. We describe the first case of a homozygous 20209C>T mutation as the cause of deep vein thrombosis in a Spanish patient.

Case and methods:

The 56-year-old male patient with a partial tear of the Achilles tendon developed calf (tibial) deep vein thrombosis after immobilization and was treated with an anticoagulant. To determine if the deep vein thrombosis was of genetic origin, a peripheral blood DNA sample was analysed for the presence of the three most frequent mutations associated with thrombotic events: factor V Leiden (1691G>A), prothrombin (20210G>A) and methylene tetrahydrofolate reductase (677C>T). The presence or absence of the normal allele of prothrombin could not be determined using the PTH-FV-MTHFR StripAssay (Vienna Lab).

Results:

Comprehensive analysis showed that the patient had a variant interfering with the polymerase chain reaction product, we sequenced the entire prothrombin gene and found that the patient had a homozygous C>T mutation at position 20209; this interfered with the polymerase chain reaction product, which needs a C at this position to be able to bind to the wild-type probe present in the test strip.

Conclusion:

The homozygous 20209C>T mutation and the presence of the mutation 677C>T in heterozygosity explained the patient’s deep vein thrombosis because the combination of mutations would increase the risk of thrombosis. Suitable genetic counselling should be provided to the patient and first-degree relatives as it important to detect prothrombin gene variants that could increase risk for thrombotic events.  相似文献   

突变理论中的哲学问题初探   总被引：1，自引：0，他引：1  

张强 《陕西师范大学学报(哲学社会科学版)》2001,30(4):73-76

突变理论通过探讨客观世界中不同层次上各类系统普遍存在着的突变式质变过程,揭示出系统突变式质变的一般方式,说明了突变在系统自组织演化过程中的普遍意义,从而为马克思主义哲学的发展提供了新的科学依据.  相似文献   

徽州文化的基因、特质与解构     

章尚正 《合肥教育学院学报》2014,(5):70-77

徽州文化是代表中国明清社会从“农业的系统”向“商业的系统”转变之际的特异性与先导性的地域文化标本。徽州文化的独特性取决于它的文化基因,包括移民型人口结构、宗法制社会结构、商贾为重的经济结构与崇儒尊孔奉朱的精神结构。徽州文化的特质是既脱胎于中华文化母体,又成为新兴商业文化的先驱者,成为新旧文化二律背后的共存体,表现出许多彼此矛盾又自我调谐的文化表征,其中最典型的为：社会价值与人生价值观上的崇儒与重商,人生态度上的内敛与进取,生活方式上的节俭与时尚。徽州文化解构、降格为普通地域文化,最根本、最关键的动因是构成徽文化特质的内在基因产生了变异：移民型人口结构发生反向移民,宗法制社会结构彻底瓦解,以商贾为重的经济结构被迫转型,崇儒尊孔奉朱的精神结构逐渐涣散,而这种种基因的嬗变受制于内外环境的变革压力。  相似文献   

Deregulation of microRNA expression in thyroid tumors简     

Zi-ming YUAN  Zhi-li YANG  Qi ZHENG 《Journal of Zhejiang University. Science. B》2014,15(3):212-224

MicroRNAs (miRNAs or miRs) are endogenous non-coding RNAs that negatively regulate gene expression 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 expression 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   

一种新型混合遗传算法及其应用     

侯丽萍  石磊 《科技通报》2012,28(5):159-162,166

根据遗传算法和人工蜂群算法各自特点,在遗传算法框架上,利用人工蜂群算法中跟随蜂选择\搜索策略,代替遗传算法中的变异操作,提出一种基于人工蜂群算法跟随蜂选择\搜索的混合遗传算法,并应用到0-1背包问题中。实验结果表明了该算法的有效性。  相似文献