全文获取类型
收费全文 | 808篇 |
免费 | 58篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 11篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 18篇 |
2016年 | 25篇 |
2015年 | 36篇 |
2014年 | 42篇 |
2013年 | 66篇 |
2012年 | 40篇 |
2011年 | 71篇 |
2010年 | 54篇 |
2009年 | 37篇 |
2008年 | 39篇 |
2007年 | 38篇 |
2006年 | 39篇 |
2005年 | 39篇 |
2004年 | 37篇 |
2003年 | 37篇 |
2002年 | 37篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1979年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 9篇 |
1973年 | 3篇 |
1969年 | 1篇 |
排序方式: 共有866条查询结果,搜索用时 187 毫秒
61.
Lucio Marcello Suraj Menon Pauline Ward Jonathan M Wilkes Nicola G Jones Mark Carrington J David Barry 《BMC bioinformatics》2007,8(1):143
Background
Trypanosomes are coated with a variant surface glycoprotein (VSG) that is so densely packed that it physically protects underlying proteins from effectors of the host immune system. Periodically cells expressing a distinct VSG arise in a population and thereby evade immunity. The main structural feature of VSGs are two long α-helices that form a coiled coil, and sets of relatively unstructured loops that are distal to the plasma membrane and contain most or all of the protective epitopes. The primary structure of different VSGs is highly variable, typically displaying only ~20% identity with each other. The genome has nearly 2000 VSG genes, which are located in subtelomeres. Only one VSG gene is expressed at a time, and switching between VSGs primarily involves gene conversion events. The archive of silent VSGs undergoes diversifying evolution rapidly, also involving gene conversion. The VSG family is a paradigm for α helical coiled coil structures, epitope variation and GPI-anchor signals. At the DNA level, the genes are a paradigm for diversifying evolutionary processes and for the role of subtelomeres and recombination mechanisms in generation of diversity in multigene families. To enable ready availability of VSG sequences for addressing these general questions, and trypanosome-specific questions, we have created VSGdb, a database of all known sequences. 相似文献62.
63.
p53 Modulates Notch Signaling in MCF‐7 Breast Cancer Cells by Associating With the Notch Transcriptional Complex Via MAML1 下载免费PDF全文
Jieun Yun Ingrid Espinoza Antonio Pannuti Damian Romero Luis Martinez Mary Caskey Adina Stanculescu Maurizio Bocchetta Paola Rizzo Vimla Band Hamid Band Hwan Mook Kim Song‐Kyu Park Keon Wook Kang Maria Laura Avantaggiati Christian R. Gomez Todd Golde Barbara Osborne Lucio Miele 《Journal of cellular physiology》2015,230(12):3115-3127
64.
Angiotensin receptor I stimulates osteoprogenitor proliferation through TGFβ‐mediated signaling 下载免费PDF全文
65.
Laura Del Latte Francesca Bortolin Omar Rota-Stabelli Giuseppe Fusco Lucio Bonato 《ZooKeys》2015,(510):31-47
Stenotaenia is one of the largest and most widespread genera of geophilid centipedes in the Western Palearctic, with a very uniform morphology and about fifteen species provisionally recognized. For a better understanding of Stenotaenia species-level taxonomy, we have explored the possibility of using molecular data. As a preliminary assay, we sampled twelve populations, mainly from the Italian region, and analyzed partial sequences of the two genes COI and 28S. We employed a DNA-barcoding approach, complemented by a phylogenetic analysis coupled with divergence time estimation. Assuming a barcoding gap of 10–16% K2P pairwise distances, we found evidence for the presence of at least six Stenotaenia species in the Italian region, which started diverging about 50 million years ago, only partially matching with previously recognized species. We found that small-sized oligopodous species belong to a single clade that originated about 33 million years ago, and obtained some preliminary evidence of the related genus Tuoba being nested within Stenotaenia. 相似文献
66.
Sinara Santos Jardim André Passaglia Schuch Camila Moura Pereira Elgion Lucio Silva Loreto 《Cell stress & chaperones》2015,20(5):843-851
There are many complex interactions between transposable elements (TEs) and host genomes. Environmental changes that induce stressful conditions help to contribute for increasing complexity of these interactions. The transposon mariner-Mos1 increases its mobilization under mild heat stress. It has putative heat shock elements (HSEs), which are probably activated by heat shock factors (HSFs). Ultraviolet radiation (UVC) is a stressor that has been suggested as able to activate heat shock protein genes (Hsp). In this study, we test the hypothesis that if UVC induces Hsp expression, as heat does, it could also promote mariner-Mos1 transposition and mobilization. The Drosophila simulans white-peach is a mutant lineage that indicates the mariner-Mos1 transposition phenotypically through the formation of mosaic eyes. This lineage was exposed to UVC or mild heat stress (28 °C) in order to evaluate the induction of mariner-Mos1 expression by RT-qPCR, as well as the mariner-Mos1 mobilization activity based on the count number of red spots in the eyes. The effects of both treatments on the developmental time of flies and cell cycle progression were also investigated. Both the analysis of eyes and mariner-Mos1 gene expression indicate that UVC radiation has no effect in mariner-Mos1 transposition, although heat increases the expression and mobilization of this TE soon after the treatment. However, the expression of Hsp70 gene increased after 24 h of UVC exposure, suggesting different pathway of activation. These results showed that heat promotes mariner-Mos1 mobilization, although UVC does not induce the expression or mobilization of this TE.
Electronic supplementary material
The online version of this article (doi:10.1007/s12192-015-0611-2) contains supplementary material, which is available to authorized users. 相似文献67.
68.
Zarrelli A Sgambato A Petito V De Napoli L Previtera L Di Fabio G 《Bioorganic & medicinal chemistry letters》2011,21(15):4389-4392
Silybin is the major flavonolignan of silymarin and it displays a plethora of biological effects, generally ascribed to its antioxidant properties. Herein we shall describe an efficient synthetic strategy to obtain a variety of new and more water-soluble silybin and 2,3-dehydrosilybin (DHS) derivatives in which the 23-hydroxyl group was converted to a sulfate, phosphodiester, or amine group, using a solution-phase approach. Furthermore a new and efficient method for the preparation of DHS from silybin was developed and optimised.The antioxidant properties of the new compounds were evaluated in a cellular model in vivo and they displayed an antioxidant activity comparable to or higher than silybin and DHS, being able to prevent H2O2-induced generation of intracellular reactive oxygen species (ROS). Most of the derivatives also displayed a better hydrophilicity while retaining the biological activities of silybin and they might broaden the in vivo applications of this class of natural compounds. 相似文献
69.
70.
Monari E Casali C Cuoghi A Nesci J Bellei E Bergamini S Fantoni LI Natali P Morandi U Tomasi A 《Proteome science》2011,9(1):55-10