全文获取类型
收费全文 | 2423篇 |
免费 | 267篇 |
出版年
2023年 | 17篇 |
2022年 | 24篇 |
2021年 | 65篇 |
2020年 | 31篇 |
2019年 | 43篇 |
2018年 | 51篇 |
2017年 | 42篇 |
2016年 | 84篇 |
2015年 | 159篇 |
2014年 | 159篇 |
2013年 | 151篇 |
2012年 | 228篇 |
2011年 | 185篇 |
2010年 | 120篇 |
2009年 | 102篇 |
2008年 | 135篇 |
2007年 | 157篇 |
2006年 | 129篇 |
2005年 | 139篇 |
2004年 | 106篇 |
2003年 | 97篇 |
2002年 | 115篇 |
2001年 | 21篇 |
2000年 | 15篇 |
1999年 | 20篇 |
1998年 | 23篇 |
1997年 | 14篇 |
1996年 | 23篇 |
1995年 | 12篇 |
1994年 | 16篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 9篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 17篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1974年 | 4篇 |
1973年 | 7篇 |
1970年 | 4篇 |
1969年 | 7篇 |
1962年 | 5篇 |
排序方式: 共有2690条查询结果,搜索用时 46 毫秒
191.
Montenarh M 《Cell and tissue research》2010,342(2):139-146
Protein phosphorylation is a key regulatory post-translational modification and is involved in the control of many cellular processes. Protein kinase CK2, formerly known as casein kinase II, which is a ubiquitous and highly conserved protein serine/threonine kinase, plays a central role in the control of a variety of pathways in cell proliferation, transformation, apoptosis and senescence. An understanding of the regulation of such a central protein kinase would greatly help our comprehension of the regulation of many pathways in cellular regulation. A number of reviews have addressed the detection, the development, and the characterization of inhibitors of CK2. The present review focuses on possible natural regulators of CK2, i.e. proteins and other cellular factors that bind to CK2 and thereby regulate its activity. 相似文献
192.
193.
Audrey Coornaert Alisa Lu Pierre Mandin Mathias Springer Susan Gottesman Maude Guillier 《Molecular microbiology》2010,76(2):467-479
Numerous small RNAs regulators of gene expression exist in bacteria. A large class of them binds to the RNA chaperone Hfq and act by base pairing interactions with their target mRNA, thereby affecting their translation and/or stability. They often have multiple direct targets, some of which may be regulators themselves, and production of a single sRNA can therefore affect the expression of dozens of genes. We show in this study that the synthesis of the Escherichia coli pleiotropic PhoPQ two‐component system is repressed by MicA, a σE‐dependent sRNA regulator of porin biogenesis. MicA directly pairs with phoPQ mRNA in the translation initiation region of phoP and presumably inhibits translation by competing with ribosome binding. Consequently, MicA downregulates several members of the PhoPQ regulon. By linking PhoPQ to σE, our findings suggest that major cellular processes such as Mg2+ transport, virulence, LPS modification or resistance to antimicrobial peptides are modulated in response to envelope stress. In addition, we found that Hfq strongly affects the expression of phoP independently of MicA, raising the possibility that even more sRNAs, which remain to be identified, could regulate PhoPQ synthesis. 相似文献
194.
Gentner R Gorges S Weise D aufm Kampe K Buttmann M Classen J 《Current biology : CB》2010,20(20):1869-1874
How motor skills are stored in the nervous system represents a fundamental question in neuroscience. Although musical motor skills are associated with a variety of adaptations [1-3], it remains unclear how these changes are linked to the known superior motor performance of expert musicians. Here we establish a direct and specific relationship between the functional organization of the corticomuscular system and skilled musical performance. Principal component analysis was used to identify joint correlation patterns in finger movements evoked by transcranial magnetic stimulation over the primary motor cortex while subjects were at rest. Linear combinations of a selected subset of these patterns were used to reconstruct active instrumental playing or grasping movements. Reconstruction quality of instrumental playing was superior in skilled musicians compared to musically untrained subjects, displayed taxonomic specificity for the trained movement repertoire, and correlated with the cumulated long-term training exposure, but not with the recent past training history. In violinists, the reconstruction quality of grasping movements correlated negatively with the long-term training history of violin playing. Our results indicate that experience-dependent motor skills are specifically encoded in the functional organization of the primary motor cortex and its efferent system and are consistent with a model of skill coding by a modular neuronal architecture [4]. 相似文献
195.
196.
Yongsheng Chen Imad Zein Everton Alen Brenner Jeppe Reitan Andersen Mathias Landbeck Milena Ouzunova Thomas Lübberstedt 《BMC plant biology》2010,10(1):12
Background
Reduced lignin content leads to higher cell wall digestibility and, therefore, better forage quality and increased conversion of lignocellulosic biomass into ethanol. However, reduced lignin content might lead to weaker stalks, lodging, and reduced biomass yield. Genes encoding enzymes involved in cell wall lignification have been shown to influence both cell wall digestibility and yield traits. 相似文献197.
Christian Tanislav Manfred Kaps Marek Jauss Erwin Stolz Wolfgang Pabst Max Nedelmann Mathias Grebe Frank Reichenberger Jens Allendoerfer 《BMC neurology》2010,10(1):123
Background
In patients with patent foramen ovale (PFO) there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS) over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO. 相似文献198.
199.
Introduction
Development of cell therapies for repairing the intervertebral disc is limited by the lack of a source of healthy human disc cells. Stem cells, particularly mesenchymal stem cells, are seen as a potential source but differentiation strategies are limited by the lack of specific markers that can distinguish disc cells from articular chondrocytes. 相似文献200.
Dolowschiak T Chassin C Ben Mkaddem S Fuchs TM Weiss S Vandewalle A Hornef MW 《PLoS pathogens》2010,6(11):e1001194
The epithelium efficiently attracts immune cells upon infection despite the low number of pathogenic microbes and moderate levels of secreted chemokines per cell. Here we examined whether horizontal intercellular communication between cells may contribute to a coordinated response of the epithelium. Listeria monocytogenes infection, transfection, and microinjection of individual cells within a polarized intestinal epithelial cell layer were performed and activation was determined at the single cell level by fluorescence microscopy and flow cytometry. Surprisingly, chemokine production after L. monocytogenes infection was primarily observed in non-infected epithelial cells despite invasion-dependent cell activation. Whereas horizontal communication was independent of gap junction formation, cytokine secretion, ion fluxes, or nitric oxide synthesis, NADPH oxidase (Nox) 4-dependent oxygen radical formation was required and sufficient to induce indirect epithelial cell activation. This is the first report to describe epithelial cell-cell communication in response to innate immune activation. Epithelial communication facilitates a coordinated infectious host defence at the very early stage of microbial infection. 相似文献