濒危植物格氏栲叶片基因组DNA提取方法研究

格氏栲植物体内酚类、多糖等次生物质含量较高,严重影响提取其基因组DNA的产量和质量。通过对格氏栲叶片DNA几种提取方法获得的DNA质量分析。结果表明,改良CTAB法是最为理想的提取方法。加入质量分数为10％的PVPP粉与材料充分研磨,在提取缓冲液中加入体积分数为3％的β-巯基乙醇,能有效地去除材料中的多酚类物质;用氯仿／异戊醇（24：1）抽提裂解液2次所获得的上清,加入1／5倍体积的7．5mol／LNH4Ac,再用异丙醇沉淀DNA,可以有效去除多糖的干扰,所提取的DNA纯度较高,可用于PCR扩增。     

改良CTAB法对白梨品种DNA提取效果的研究

采用改良CTAB法对15个白梨品种叶片DNA提取情况进行了研究,考察了Vc和β-巯基乙醇抗氧化效果,所获得DNA样品经电泳、单酶切以及PCR检测,结果表明用氯仿/异戊醇混合萃取液多萃取几次可有效减少高蛋白质含量样品中的蛋白质的含量;用5mol/L的NaCl溶液能有效降低梨DNA样品中多糖的含量;Vc抗氧化效果优于β-巯基乙醇,Vc用量在0.1~0.30g/g样品时,可有效减少提取过程中酚类氧化。     

几种药用植物基因组DNA提取方法研究

采用改良2×CTAB法和改良SDS法提取富含多糖和次生代谢物质的几种药用植物不同器官基因组DNA,并用紫外分光光度计分析,凝胶电泳和PCR扩增进行鉴定。结果表明:改良2×CTAB法和改良SDS法均能有效去除不同药用植物材料中的蛋白质、多糖、酚类及其他次生代谢物质,获得较高质量基因组DNA。但与改良SDS法相比,改良2×CTAB法提取的基因组DNA质量更好。     

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。     

小鼠粪便细菌基因组DNA提取方法比较

分别将研磨、水煮两种预处理方法和改良CTAB法、试剂盒法两种提取方法进行组合,比较提取小鼠粪便细菌基因组DNA的效果。结果发现,研磨预处理过的样品提取到的细菌基因组DNA的浓度和纯度均高于水煮预处理过的样品,研磨结合改良CTAB法提取到的DNA完整性好于其他方法,研磨结合改良CTAB法是一种提取粪便细菌基因组DNA较为实用可靠的方法。     

用CTAB法提取植物DNA的技术改进

本文以富含酚类物质的牡丹叶片为材料,就CTAB法提取植物组织中的DNA的方法做了进一步的改进,主要涉及二巯基乙醇的用量、氯仿／异戊醇的用量、以及DNA晾干方法的改进等,为后续的分子生物学试验提供了纯净的基因组DNA。     

山西省沙棘品种AFLP的初步分析

沙棘体内酚类物质和蛋白质含量较高,影响了基因组DNA提取的产量。采用改良CTAB法对观光木基因组DNA进行提取,经过紫外吸收、琼脂糖凝胶电泳、双酶切和AFLP标记检测,结果表明:改良CTAB法提取的基因组DNA吸光值OD260/OD280为1.7～1.9,DNA无降解现象和杂质污染;基因组DNA双酶切彻底,并且APLP扩增的条带较多而且清晰。从而建立了适合沙棘AFLP分子标记的反应体系,为利用AFLP标记对沙棘进行分子生物学研究及分子育种奠定了基础。     

药用植物虎杖毛状根DNA提取方法研究

采用高盐低pH法、改良SDS法、CTAB法、改良CTAB法提取发根农杆菌ATCC11325感染蓼科多年生药用植物虎杖（Polygonum cuspidatum Sieb．et Zucc．）叶片产生毛状根的基因组DNA,并进行了电泳分析、含量检测及特异PCR扩增．结果表明：改良CTAB法解决了虎杖富合多酚、多糖等类物质难以提取高质量DNA的问题,提取的DNA质量较好,纯度较高,能满足进一步的实验要求．     

三叶木通RAPD最佳反应体系的研究

RAPD技术是一种新的分子标记技术,DNA质量是保证RAPD分析成功的关键。为获得高质量的木通属植物基因组DNA,本文采用SDS法、改良CTAB法、高盐低pH值法提取三叶木通总DNA。结果表明,高盐低pH值法不适用于木通属植物DNA的提取;改良CTAB法是合适的DNA提取方法,它们获得DNA模板纯度高、质量好,可直接用于RAPD分析。同时,对RAPD反应条件中的一些重要参数进行摸索和优化试验,建立适合木通属植物RAPD分析应用的体系,其组成为:反应液总体积为25μL,2.5μL 10×PCR缓冲液、0.16 mmol/L dNTPs2、.0 mmol/L Mg2 、0.64μmol/L引物、1 U/μL Taq酶4、0 ng/25μLDNA模板。PCR循环体系为:94℃,4 min-[-94℃,30 s-37℃,90 s-72℃,60 s-]-72℃,5 min,40个循环。     

一种提取茶树基因组DNA的方法——改良的CTAB法

采用改良的CTAB法与常规的CTAB法提取茶叶基因组DNA进行比较,结果证明改良的方法得到DNA浓度和纯度高,无蛋白质和RNA等杂质影响,并且可以很好的应用于ISSR分子标记分析。     

汉字倒说

汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

钱生钱!

我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

Inequalities for inscribed simplexes

The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

微薄的薪水,高尚的情操

现在,我们可以没有面包,没有钱,没有房子,没有车子……但我们唯独不能丢失的是高尚的情操,笃定的信念,还有,满满的希望!     

Virtual reality approach for 3D large model browsing on web site

Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching.     

An Analysis of Individualism in the Declaration of Independence

The awareness of individualism can be traced back to the period of American Revolution when the Declaration of Independence was produced.It expressed basic beliefs concerning freedom,equality,democracy,privacy and the relationship between people and government,which were exactly what the philosophy of individualism mostly dealt with at that time.This paper is to exploit the essence of individualism by analyzing the Declaration .The analysis enables us to reconsider its significance to the issue of America human rights and foreign policies.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.