运动性疲劳分子生物学机制的研究进展

从四个方面(细胞内分子、细胞膜分子、细胞外分子和其他广泛存在的分子和离子)综合分析运动性疲劳分子生物学机制的研究进展,以期达到完善运动性疲劳机制理论体系的目的.     

金融企业DNA的应用及实现

金融企业通过使用电子银行/支付安全系统(DNA)技术后可以把交易资料和授权资料分两个渠道传送到银行账户主机。DNA系统改变了银行各种电子交易处理平台沿用几十年的单轨式交易传送系统,而采用双轨式的交易传送系统,有效解决了因客户重要金融资料遗失或被盗后引发的风险。本文以一商业银行对此技术的应用及实现进行阐述。     

盐浓度、酸碱度及DNA浓度对增色效应实验的影响

研究了DNA在不同浓度，不同pH值和不同氯化钠溶液中紫外吸光度的变化，为设计DNA的增色效应实验提供了依据。     

Enhancing cellular immune response to HBV M DNA vaccine in mice by codelivery of interleukin-18 recombinant

Objective: To investigate the effect of interleukin-18 (IL-18) on immune response induced by plasmid encoding hepatitis B virus middle protein antigen and to explore new strategies for prophylactic and therapeutic HBV DNA vaccines. Methods: BALB/c mice were immunized with pCMV-M alone or co-immunized with pcDNA3-18 and pCMV-M and then their sera were collected for analysing anti-HBsAg antibody by ELISA; splenocytes were isolated for detecting specific CTL response and cytokine assay in vitro. Results: The anti-HBs antibody level of mice co-immunized with pcDNA3-18 and pCMV-M was slightly higher than that of mice immunized with pCMV-M alone, but there was not significantly different (P>0.05). Compared with mice injected with pCMV-M, the specific CTL cytotoxity activity of mice immunized with pcDNA3-18 and pCMV-M was significantly enhanced (P<0.05) and the level of IFN-γ in supernatant of splenocytes cultured with HBsAg in vitro was significantly elevated (P<0.05) while the level of IL-4 had no significant difference (P>0.05). Conclusion: The plasmid encoding IL-18 together with HBV M gene DNA vaccines may enhance specific TH1 cells and CTL cellular immune response induced in mice, so that IL-18 is a promising immune adjuvant.     

Dependence of nucleotide physical properties on their placement in codons and determinative degree

INTRODUCTION It is well-known from the genetic code structure that there exists a connection between codons and physical and chemical amino acid properties (Lewin, 1983). Codon properties in turn are defined by physical properties of the nucleotides from which they are compounded (Ratner, 1985; 2000). The most important properties of nucleotides as complex three-dimensional molecules are their dipole moment, heat of formation and energy of the most stable con- formation (Schneider and Be…     

DNA甲基化异常与肿瘤发生的研究

DNA甲基化是真核生物DNA的正常内源性修饰方式 ,它由DNA甲基化转移酶催化发生。但DNA甲基化异常在肿瘤发生中却起着极为重要的作用 ,它主要表现为抑癌基因高甲基化所致的基因失活和原癌基因低甲基化所致的基因激活 ,引起与细胞增殖、分化相关基因表达异常 ,造成细胞恶变形成肿瘤。文章总结了DNA甲基化异常对肿瘤相关基因表达的影响 ,在肿瘤发生中的可能机制及针对高甲基化的治疗方案     

“观察DNA和RNA在细胞中的分布”实验的改进研究

本文对＂观察DNA和RNA在细胞中的分布＂实验提出了改进方法：人的口腔上皮细胞可直接染色观察,若要烘干必须用低温,不需用HC l进行水解;洋葱鳞片叶内表皮细胞应先用质量分数为4%的HC l溶液水解,然后用质量分数为1%的NaHCO3溶液清洗。通过改进,染色现象明显。     

辽东楤木对一次力竭小鼠血淋巴细胞DNA损伤的影响

目的：急性运动可引起氧自由基产生增加,从而导致机体一系列病理损伤。通过给小鼠补充辽东楤木根皮提取物,5周后进行急性一次力竭运动,观察运动源性自由基对血淋巴细胞DNA的损伤情况以及血清丙二醛（MDA）含量、血清超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）活性的变化,探讨辽东楤木对一次性力竭性运动后机体自由基代谢的影响。方法：昆明种小鼠64只,随机分为四组：正常对照组（NC组）16只、运动对照组（EC组）16只、运动＋辽东楤木组（EA组）16只,运动＋人参组（EP组）16只、除正常对照组外,其他各组小鼠于最后一次灌胃后,次日晨进行一次力竭游泳运动后,取样。采用单细胞凝胶电泳法、硫代巴比妥酸法、黄嘌呤氧化酶法和二硫代二硝基苯甲酸法分别测定血液淋巴细胞DNA的损伤、血清MDA的含量、血清SOD和GSH-Px的活性。结果：（1）与NC组相比,EC组大鼠血清MDA含量显著增加（P〈0.01）,血清SOD和GSH-Px活性显著下降（P〈0.01）。与EC组相比,EA组大鼠血清MDA含量显著下降（P〈0.01）,血清SOD和GSH-Px活性显著增高（P〈0.01）;EP组大鼠血清MDA含量显著下降（P〈0.01）,血清SOD和GSH-Px活性显著增高（P〈0.01）。（2）与NC组相比,EC组大鼠血液淋巴细胞尾长（Tail length）、尾矩（Tail moment）及椭圆矩（Olive moment）显著增加（P〈0.01）。与EC组相比,EA组大鼠血液淋巴细胞Tail length、Tail moment、Olive moment显著降低（P〈0.01）;EP组大鼠血液淋巴细胞尾长、尾短和椭圆矩显著降低（P〈0.01）。结论：1）辽东楤木可以提高小鼠血清SOD、GSH-Px的活性,降低血清MDA的含量,减少OH.等对DNA的直接损伤。2）辽东楤木对一次力竭运动导致的小鼠血液淋巴细胞DNA的损伤具有保护作用,与人参的作用效果相类似。     

Scaling behavior of nucleotide cluster in DNA sequences

In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P（S） ∝ e^-αs＇ where S represents nucleotide cluster size. The cluster-size distribution P（S1＋S2） with the total size of sequential C-G cluster and A-T cluster S1＋S2 were also studied. P（S1＋S2） follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L（n） and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.     

Evaluation and application of an efficient plant DNA extraction protocol for laboratory and field testing

Nucleic acids in plant tissue lysates can be captured quickly by a cellulose filter paper and prepared for amplification after a quick purification.In this study,a published filter paper strip method was modified by sticking the filter paper on a polyvinyl chloride resin(PVC)sheet.This modified method is named EZ-D,for EASY DNA extraction.Compared with the original cetyl trimethylammonium bromide(CTAB)method,DNA extracted by EZ-D is more efficient in polymerase chain reaction(PCR)amplification due to the more stable performance of the EZ-D stick.The EZ-D method is also faster,easier,and cheaper.PCR analyses showed that DNA extracted from several types of plant tissues by EZ-D was appropriate for specific identification of biological samples.A regular PCR reaction can detect the EZ-D-extracted DNA template at concentration as low as 0.1 ng/μL.Evaluation of the EZ-D showed that DNA extracts could be successfully amplified by PCR reaction for DNA fragments up to 3000 bp in length and up to 80%in GC content.EZ-D was successfully used for DNA extraction from a variety of plant species and plant tissues.Moreover,when EZ-D was combined with the loop-mediated isothermal amplification(LAMP)method,DNA identification of biological samples could be achieved without the need for specialized equipment.As an optimized DNA purification method,EZ-D shows great advantages in application and can be used widely in laboratories where equipment is limited and rapid results are required.