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排序方式: 共有299条查询结果,搜索用时 15 毫秒
1.
以编码人全长的OBmRNA为模板,用RT-PCR法获得了编码146个氨基酸残基的OBcDNA,并经EcoRI和BamHI双酶切克隆至原核质表达质粒pGEX-1λT中,通过IPTG诱导,以谷胱苷肽巯基转移酶融合蛋白(GSP)方式进行了表达。结论:在原核细胞中获得高效表达。 相似文献
2.
Zhao RL Desjardin DE Soytong K Hyde KD 《Journal of Zhejiang University. Science. B》2008,9(10):779-786
We present an overview of previous research results on the molecular phylogenetic analyses in Agaricales and its higher ranks (Agaricomycetes/Agaricomycotina/Basidiomycota) along with the most recent treatments of taxonomic systems in these taxa. Establishing phylogenetic hypotheses using DNA sequences, from which an understanding of the natural evolutionary relationships amongst clades may be derived, requires a robust dataset. It has been recognized that single-gene phylogenies may not truly represent organismal phylogenies, but the concordant phylogenetic genealogies from multiple-gene datasets can resolve this problem. The genes commonly used in mushroom phylogenetic research are summarized. 相似文献
3.
实验教学是培养大学生创新能力的重要途径和手段,但是传统实验教学模式存在较多问题,不能满足培养高素质医学人才的要求。"生物化学与分子生物学"是临床医学专业的基础课,而实验教学是该课程教学内容的一部分,是培养医学生创新能力的重要途径和手段。以"生物化学与分子生物学"实验教学为例,从优化实验教学设计、丰富实验教学内容、改革考核方式等方面进行实践和总结,阐述如何在实验教学中培养学生创新思维,提升实验教学质量,为实验教学改革提供新的思路和参考。 相似文献
4.
语篇组织成分之间语义关系的建立需要衔接手段来实现.从语义关联方式来看,衔接手段可分为衔接类(指称衔接、结构衔接、词汇衔接)和连接类(显性连接和隐性连接).从形式特征来看,指称衔接、结构衔接、以及显性连接更具标记性,由此形成的语义关联也较显明易辨. 相似文献
5.
话语标记语是言语交际中一种十分常见的话语现象,在不同的交际条件下具有不同的语用功能。人们在交际时或多或少地受元语用意识的指导与调控,而且这种元语用意识会在各种不同语言层面上有所反映。因此,话语标记语是标示说话人的元语用意识的一种语言手段。不同类型的话语标记语可以从不同的角度反映说话人的元语用意识。 相似文献
6.
生物分子系统学研究中的RAPD技术 总被引:1,自引:0,他引:1
RAPD技术在Williams等人于1990年首先提出后,在检测DNA多态性方面受到了广泛的应用.RAPD技术以其简单、快速、信息量大等特点渗透在基因诊断,法医检测,生物药品的检验,生物种群关系的研究各个领域.以核酸为指标构建的生物系统进化树,不受主观因素的影响,避免了经典植物系统学的人为影响因素,因而受到广泛应用,在分子系统研究中出现了RFLP,RAPDDNA和RNA测序等分子生物学技术,其中RAPD技术不需要经过DNA分子克隆、分子杂交等繁锁步骤,也不需用放射性同位素显示,并且多态性检出率高,因而受到普遍关注. 相似文献
7.
林松竹 《中国教育科研与探索》2006,(5):17-19
本文进行了硫酸、对甲苯磺酸、氨基磺酸、强酸性阳离子交换树脂、六水三氯化铁、二水二氯化锡、十八水硫酸铝、十二水合硫酸铁铵、一水硫酸氢钠、固体超强酸、杂多酸和沸石分子筛等催化剂催化合成丁酸异戊酯的比较研究。 相似文献
8.
Lakshmi Lavanya Reddy Swarup A. V. Shah Alpa J. Dherai Chandrashekhar K. Ponde Tester F. Ashavaid 《Indian journal of clinical biochemistry : IJCB》2016,31(1):87-92
Acute coronary syndrome (ACS) is a term for a range of clinical signs and symptoms suggestive of myocardial ischemia. It results in functional and structural changes and ultimately releasing protein from injured cardiomyocytes. These cardiac markers play a major role in diagnosis and prognosis of ACS. This study aims to assess the efficacy of heart type fatty acid binding protein (h-FABP) as a marker for ACS along with the routinely used hs-TropT. In our observational study, plasma h-FABP (cut-off 6.32 ng/ml) and routinely done hs-Trop T (cutoff 0.1 and 0.014 ng/ml) were estimated by immunometric laboratory assays in 88 patients with acute chest pain. Based on the clinical and laboratory test findings the patients were grouped into ACS (n = 41) and non-ACS (n = 47). The diagnostic sensitivity, specificity, NPV, PPV and ROC curve at 95 % CI were determined. Sensitivity of hs-TropT (0.1 ng/ml), hs-TropT (0.014 ng/ml) and h-FABP were 53, 86 and 78 % respectively and specificity for the same were 98, 73 and 70 % respectively. Sensitivity, specificity and NPV calculated for a cut-off combination of hs-TropT 0.014 ng/ml and h-FABP was 100, 51 and 100 % respectively. These results were substantiated by ROC analysis. Measurement of plasma h-FABP and hs-TropT together on admission appears to be more precise predictor of ACS rather than either hs-Trop T or h-FABP. 相似文献
9.
Shalini M Yogeeswari P Sriram D Induja S 《Journal of Zhejiang University. Science. B》2007,8(1):45-55
Objective: To study the effect of halo substitution on disubstituted aryl semicarbazones on the anticonvulsant potential and model the activity based on quantum mechanics. Methods: A series of twenty-six compounds of N^4-(4-bromo-3-methylphenyl) semicarbazones were synthesized and evaluated for the anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure threshold tests. Some potential compounds were also tested in the subcutaneous strychnine (scSTY) and subcutaneous picrotoxin (scPIC) seizure threshold tests. The synthesized compounds were tested for behavioral impairment and CNS (central nervous system) depression in mice. Quantum mechanical modelling was carried out on these compounds to gain understanding on the structural features essential for activity. Results: Some compounds possessed broad spectrum anticonvulsant activity as indicated by their effect in pentylenetetrazole, strychnine, picrotoxin and maximal electroshock seizures models in resemblance to other aryl semicarbazone derivatives reported earlier. The higher the difference in HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels was, the greater was the activity profile. Conclusion: The pharmacophoric requirements for compounds to exhibit anticonvulsant activity that includes one aryl unit in proximity to a hydrogen donor-acceptor domain and an electron donor have been justified with the molecular orbital surface analysis of the synthesized compounds. 相似文献
10.
唐丽玲 《兰州石化职业技术学院学报》2011,11(2):74-77
通过语料库文本分析的方式,把中国英语学习者(英语专业学生)书面语中推导性话语标记语的使用情况和英语本族语者使用情况进行对比。结果显示,(1)中国英语学习者书面语中推导性话语标记语的使用存在严重的过多和过少使用并存现象,且呈简单化、口语化倾向;(2)推导性标记语使用水平会随着学习者语言水平的提高而有所提高,但个别推导性标记语的使用具有语用"石化"特征。 相似文献