全文获取类型
收费全文 | 209篇 |
免费 | 12篇 |
国内免费 | 18篇 |
专业分类
系统科学 | 7篇 |
丛书文集 | 6篇 |
教育与普及 | 3篇 |
现状及发展 | 4篇 |
综合类 | 219篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 13篇 |
2013年 | 8篇 |
2012年 | 8篇 |
2011年 | 13篇 |
2010年 | 8篇 |
2009年 | 14篇 |
2008年 | 5篇 |
2007年 | 17篇 |
2006年 | 7篇 |
2005年 | 11篇 |
2004年 | 10篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有239条查询结果,搜索用时 171 毫秒
91.
从药靶的选择、蛋白质片段为基础的新药开发、以寡聚酶为新药开发的靶、工业化的结构和蛋白质数据库以及专门研究传染病的结构基因组学工程等5个方面综述了医学结构基因组学在研制新药中的作用。 相似文献
92.
针对Savage等人提出的分片包标记方案(fragment marking scheme,FMS)存在的不足,提出一种改进的分片包标记方案(IFMS),该方案通过扩大标记空间和采用动态标记概率的方法,减少了重构攻击路径所需的数据包数,降低了计算开销,同时采用40位Hash作为误差校验,显著降低了路径重构的误差率.理论分... 相似文献
93.
94.
菲厌氧降解对细菌和古细菌群落的影响 总被引:1,自引:0,他引:1
利用TRFLP技术研究了受垃圾渗滤液污染的地下沉积物中细菌和古细菌群落在菲厌氧降解前后的变化。结果表明:细菌群落在生物降解过程中变化很大,物种丰度及Shannon-Weiner指数分别由15和2.39增加到23和2.88;古细菌群落在生物降解过程中变化较小,物种丰度及Shannon-Weiner指数变化不大。 相似文献
95.
伪狂犬病病毒(PRV)糖蛋白E是一种在伪狂犬病的根除计划中具有重要作用的糖蛋白.将伪狂犬病病毒闽A株gE基因抗原编码区片段克隆到杆状病毒Bac-to-Bac系统表达载体pFastBacHTa中,获得的重组表达载体pFastBacHTa-FS转化大肠杆菌DH10BAc感受态细胞后,得到的重组Bacmid DNA在脂质体介导下转染粉蚊夜蛾Hi5细胞,通过细胞内同源重组,获得了含目的片段的重组病毒.此重组病毒感染Hi5细胞后72 h,细胞总蛋白的SDS-PAGE与Western-Blot结果表明,gE基因抗原编码区片段在Hi5细胞中得到了正确表达,表达产物约35000,占细胞总蛋白的9.31%.溶解性分析显示该片段在Hi5细胞中为不可溶性表达. 相似文献
96.
Great progress has been made in recent years in studies on the mechanism ofAgrobacterium-medicated transformation and its application. Many details of the key molecular events within the bacterial cells involved
in T-DNA transfer have been elucidated, and it is notable that some plant factors which were elusive before are purified and
characterized. Vast kinds of species, which were either recalcitrant to or not included in the host range ofAgrobacterium, can now be transformed by this bacterium, and they include the very important cereal species, gymnosperms, yeast and many
filamentous fungi. The simplein vivo transformation of tissue in intact plants and the “agrolistic” methods to transform recalcitrant plants are the two novel
technical achievements. Combined with other powerful techniques such as bacterial artificial chromosome, very large DNA fragment
can be transformed into the plant genome byAgrobacterium. Further studies will elucidate more plant-encoded factors involved in T-DNA transformation and there is a need to develop
more powerfulAgrobacterium-based transformation systems to meet different needs in basic research and crop improvement practice. 相似文献
97.
Lamarine M Mornon JP Berezovsky N Chomilier J 《Cellular and molecular life sciences : CMLS》2001,58(3):492-498
Using a set of 372 proteins representative of a variety of 56 distinct globular folds, a statistical correlation was observed
between two recently revealed features of protein structures: tightened end fragments or 'closed loops', i. e. sequence fragments
that are able in three-dimensional (3D) space to nearly close their ends (a current parameter of polymer physics), and 'topohydrophobic
positions', i. e. positions always occupied in 3D space by strong hydrophobic amino acids for all members of a fold family.
Indeed, in sequence space, the distribution of preferred lengths for tightened end fragments and that for topohydrophobic
separation match. In addition to this statistically significant similarity, the extremities of these 'closed loops' may be
preferentially occupied by topohydrophobic positions, as observed on a random sample of various folds. This observation may
be of special interest for sequence comparison of distantly related proteins. It is also important for the ab initio prediction
of protein folds, considering the remarkable topological properties of topohydrophobic positions and their paramount importance
within folding nuclei. Consequently, topohydrophobic positions locking the 'closed loops' belong to the deep cores of protein
domains and might have a key role in the folding process.
Received 1 February 2001; accepted 7 February 2001 相似文献
98.
99.
用IX因子基因内探针F9(VⅢ)对TaqI,BamHI和EcoRI酶切的50例中国人基因组DNA进行杂交分析。结果表明,所有个体经TaqI酶切的杂交片段为4.5kb和1.8kb,BamHI和EcoRI酶切的杂交片段分别为23kb和5.0 kb。基因组DNA样本中未发现限制性片段长度多态性(RFLP),这与欧美国家的民族群体中存在着IX因子基因内TaqI和BamHI的RFLP的结论不同。造成不同种族间DNA水平差异的原因,很可能与长期在不同地理环境中的进化适应有关。 相似文献
100.