全文获取类型
收费全文 | 269篇 |
免费 | 58篇 |
专业分类
327篇 |
出版年
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 14篇 |
2012年 | 15篇 |
2011年 | 15篇 |
2010年 | 11篇 |
2009年 | 5篇 |
2008年 | 15篇 |
2007年 | 19篇 |
2006年 | 14篇 |
2005年 | 20篇 |
2004年 | 11篇 |
2003年 | 19篇 |
2002年 | 18篇 |
2001年 | 16篇 |
2000年 | 22篇 |
1999年 | 16篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1977年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有327条查询结果,搜索用时 15 毫秒
61.
62.
Bork A. Berghoff Mirthe Hoekzema Lena Aulbach E. Gerhart H. Wagner 《Molecular microbiology》2017,103(6):1020-1033
Bacterial survival strategies involve phenotypic diversity which is generated by regulatory factors and noisy expression of effector proteins. The question of how bacteria exploit regulatory RNAs to make decisions between phenotypes is central to a general understanding of these universal regulators. We investigated the TisB/IstR‐1 toxin‐antitoxin system of Escherichia coli to appreciate the role of the RNA antitoxin IstR‐1 in TisB‐dependent depolarization of the inner membrane and persister formation. Persisters are phenotypic variants that have become transiently drug‐tolerant by arresting growth. The RNA antitoxin IstR‐1 sets a threshold for TisB‐dependent depolarization under DNA‐damaging conditions, resulting in two sub‐populations: polarized and depolarized cells. Furthermore, our data indicate that an inhibitory 5′ UTR structure in the tisB mRNA serves as a regulatory RNA element that delays TisB translation to avoid inappropriate depolarization when DNA damage is low. Investigation of the persister sub‐population further revealed that both regulatory RNA elements affect persister levels as well as persistence time. This work provides an intriguing example of how bacteria exploit regulatory RNAs to control phenotypic heterogeneity. 相似文献
63.
Carlos Quijano Pavel Tomancak Jesus Lopez-Marti Mikita Suyama Peer Bork Marco Milan David Torrents Miguel Manzanares 《Genome biology》2009,9(12):R176
Background
The physical organization and chromosomal localization of genes within genomes is known to play an important role in their function. Most genes arise by duplication and move along the genome by random shuffling of DNA segments. Higher order structuring of the genome occurs in eukaryotes, where groups of physically linked genes are co-expressed. However, the contribution of gene duplication to gene order has not been analyzed in detail, as it is believed that co-expression due to recent duplicates would obscure other domains of co-expression. 相似文献64.
Patrick Horn Gudrun Bokermann Dominik Cholewa Simone Bork Thomas Walenda Carmen Koch Wolf Drescher Gabriele Hutschenreuther Martin Zenke Anthony D. Ho Wolfgang Wagner 《Cytotherapy》2010,12(7):888-898
Background aimsCulture medium for mesenchymal stromal cells (MSC) is frequently supplemented with fetal calf serum (FCS). FCS can induce xenogeneic immune reactions, transmit bovine pathogens and has a high lot-to-lot variability that hampers reproducibility of results. Several studies have demonstrated that pooled human platelet lysate (HPL) provides an attractive alternative for FCS. However, little is known about the variation between different platelet lysates.MethodsWe compared activities of individual HPL on initial fibroblastoid colony-forming units (CFU-F), proliferation, in vitro differentiation and long-term culture. These data were correlated with chemokine profiles of HPL.ResultsIsolation of MSC with either HPL or FCS resulted in similar CFU-F frequency, colony morphology, immunophenotype and adipogenic differentiation potential. Osteogenic differentiation was even more pronounced in HPL than FCS. There were significant differences in MSC proliferation with different HPL, but it was always higher in comparison with FCS. Cell growth correlated with the concentration of platelet-derived growth factor (PDGF) and there was a moderate association with platelet counts. All HPL facilitated expansion for more than 20 population doublings.ConclusionsTaken together, reliable long-term expansion was possible with all HPL, although there was some variation in platelet lysates of individual units. Therefore the use of donor recipient-matched or autologous HPL is feasible for therapeutic MSC products. 相似文献
65.
66.
Frederik Wein Larissa Pietsch Rainer Saffrich Patrick Wuchter Thomas Walenda Simone Bork Patrick Horn Anke Diehlmann Volker Eckstein Anthony D. Ho Wolfgang Wagner 《Stem cell research》2010,4(2):129-139
Specific cell–cell junctions between hematopoietic stem cells (HSC) and their niche have been shown to regulate stem cell function. N-cadherin was suggested to play a central role in this process, whereas other studies indicated that it did not play an essential role in the murine model. We have analyzed the role of N-cadherin for interaction between hematopoietic progenitor cells (HPC) and supportive mesenchymal stromal cells (MSC) in a human–human setting. Expression of N-cadherin and of cadherin-11 (osteoblast cadherin) was analyzed in HPC by quantitative RT-PCR, Western blot, and flow cytometry. N-cadherin and cadherin-11 were expressed in HPC at a moderate level, whereas they were not detectable in differentiated cells. Confocal laser scanning microscopy revealed that N-cadherin and β-catenin are colocalized at the junction of HPC and MSC. siRNA knockdown of N-cadherin or cadherin-11 as well as treatment with the blocking function antibody decreased adhesive interaction of HPC to MSC. Furthermore, knockdown of N-cadherin or blocking function antibody impaired maintenance of long-term culture-initiating cells (LTC-IC) on coculture of HPC and MSC. These results indicate that N-cadherin is involved in the bidirectional interaction of human HPC with their cellular determinants in the niche. 相似文献
67.
A novel transactivation domain in parkin. 总被引:8,自引:0,他引:8
68.
69.
Medusa: a simple tool for interaction graph analysis 总被引:5,自引:0,他引:5
SUMMARY: Medusa is a Java application for visualizing and manipulating graphs of interaction, such as data from the STRING database. It features an intuitive user interface developed with the help of biologists. Medusa is optimized for accessing protein interaction data from STRING, but can be used for any type of graph from any scientific field. 相似文献
70.
Pérez AJ Perez-Iratxeta C Bork P Thode G Andrade MA 《Bioinformatics (Oxford, England)》2004,20(13):2084-2091