从新冠病毒疫苗研发看我国战略科技力量建设

强化战略科技力量是实现科技自立自强的关键。我国新冠病毒疫苗研发取得阶段性胜利与国家战略科技力量有着密不可分的关系。文章从国内外新冠病毒疫苗研发现状入手,通过分析我国新冠病毒疫苗研发科研攻关的成功经验,进一步深入思考和探索我国战略科技力量的使命定位、顶层设计、强化方式,并就进一步强化我国战略科技力量提出相应的政策建议。     

黄芪根瘤菌新表观群中心菌株与相关根瘤菌的DNA同源性分析

采用液相复性速率法测定了黄芪根瘤菌新表观群的中心菌株CA8561和JL84与近缘已知根瘤菌属种模式菌株或参比菌株的DNA同源性．结果表明，分离自中国北方地区的部分黄芪根瘤菌菌株形成了独立的新的DNA同源群，结合其它分类技术的研究结果可以认为这些菌株构成了一个新种．     

DNA标记及其在鱼类中的应用

DNA分子标记是继形态标记、细胞标记和生化标记之后发展起来的一种比较理想的遗传标记技术。本文简要介绍RFLP、RAPD、AFLP、SSR、SNP、EST、mtDNA等DNA分子标记的类型,基本原理和特点,以及分子标记技术在鱼类遗传图谱构建、基因定位和分子标记辅助育种等方面的应用前景予以展望。     

Preliminary studies on the detection ofMycobacterium avium-intracellulare complex using DNA probe from a clinical isolate

Genomic DNA from a clinical isolate ofMycobacterium avium-intracellulare complex was purified and cloned in PBR 322 at the tetracycline resistance site using Bam HI restriction enzyme. A 16 kb cloned fragment was purified, radiolabeled and used as a probe. Genomic DNA isolated from nineteen MAC strains, threeM. tuberculosis strains and oneM. kansasii strain were digested with Eco RI restriction enzyme, Southern blotted and hybridized with the 16 kb cloned and labeled fragment. Twelve MAC strains showed positive hybridization although five strains gave faint signals. Positive hybridization was noted in two out of the threeM. tuberculosis strains, possibly due to shared DNA homology. No signal was received from the singleM. kansasii strain used in this study.     

DNA分子标记技术在水生动物遗传多样性研究中的应用

简要阐述了几种常见DNA分子标记技术,如限制性片断长度多态性(restriction fragment length polymorphism,RFLP)、随机扩增多态性DNA(random amplified polymorphie DNA,RAPD)、扩增片断长度多态性(amplified fragment length polymorphism,AFLP)、简单重复序列或微卫星标记(simpie sequencerepeat,SSR)、内部简单重复序列(inter-simple sequence repeat,ISSR)和单核苷酸多态性(single nucleotidepelymorphisms,SNP)等的基本原理、技术上的优缺点及其在水生动物遗传多样性研究中的应用,包括遗传多样性的鉴定、品种亲缘关系与分类的研究和种质资源的鉴定等.最后,对DNA分子标记技术在水生动物遗传多样性应用中的存在问题进行了简单的讨论.     

芒果基因组DNA的提取方法比较

采用SDS法、改良SDS法、CTAB法、改良CTAB法提取芒果基因组DNA,并对提取的DNA进行质量比较。结果表明:改良CTAB法能较好地去除芒果叶片中的酚类和多糖杂质,提取的DNA母液浓度达767．2 ng/μl, OD260／OD280为1．89,DNA纯度和浓度在四种方法中均为最高。     

Cardiorespiratory fitness and telomere length: a systematic review

ABSTRACT

This study aimed to systematically review the association between cardiorespiratory fitness and telomere length (TL). Studies were identified from searches in Cochrane Central, PubMed, Scopus, Sportdiscus, and Web of Science databases through July 2019. Eligibility criteria included: cross-sectional, prospective, and experimental study design; outcomes included TL; results expressed the relationship between cardiorespiratory fitness and TL; studies published in English, Portuguese, or Spanish. A total of 20 articles met the inclusion criteria. Sixteen studies (80%) reported a significant relationship between cardiorespiratory fitness, or training load, and TL. Better cardiorespiratory fitness or a large cardiorespiratory training load are associated with an increase in TL. Although, TL was related to regular moderate-to-vigorous aerobic exercise and cardiorespiratory fitness in older healthy humans, it was not related to cardiorespiratory fitness among young subjects. There seems to be a positive and significant relationship between cardiorespiratory fitness and TL, mainly among middle age and older people, which emphasizes the importance of cardiorespiratory fitness for healthy ageing. Therefore, endurance exercise and better cardiorespiratory fitness may regulate the TL in middle age and older adults, slowing the cellular ageing process.     

DNA生物大分子的动力学特性与生物功能(Ⅰ)

本文全面考虑了ＤＮＡ的碱基对的相互作用、双链的整体振动效应和链内分子的集体激发等运动状态，应用在我们最近在蛋白质分子中建立的新理论与其它方法，研究了ＤＮＡ分子的动力学特性，集体激发与孤立子运动．并应用此结果深入研究ＤＮＡ的一些生物功能，如复制、转录等问题．     

DNA芯片技术及其应用

DNA芯片技术是近年发展起来的DNA分析技术，它采用高速打印或光刻合成技术可在硅片、玻璃或尼龙膜上制造DNA微阵列.样品DNA通过PCR扩增、体外转录等技术掺入荧光标记分子，与微阵列杂交后，通过荧光扫描仪扫描及计算机分析即可获得样品中大量基因序列及表达信息.该技术可应用于DNA序列测定、基因表达水平检测、基因及多态性检测、发现新基因等多个研究领域.