全文获取类型
收费全文 | 2860篇 |
免费 | 241篇 |
出版年
2023年 | 9篇 |
2022年 | 30篇 |
2021年 | 43篇 |
2020年 | 31篇 |
2019年 | 44篇 |
2018年 | 52篇 |
2017年 | 34篇 |
2016年 | 67篇 |
2015年 | 135篇 |
2014年 | 168篇 |
2013年 | 169篇 |
2012年 | 240篇 |
2011年 | 226篇 |
2010年 | 113篇 |
2009年 | 116篇 |
2008年 | 174篇 |
2007年 | 178篇 |
2006年 | 156篇 |
2005年 | 157篇 |
2004年 | 171篇 |
2003年 | 156篇 |
2002年 | 144篇 |
2001年 | 38篇 |
2000年 | 22篇 |
1999年 | 35篇 |
1998年 | 44篇 |
1997年 | 39篇 |
1996年 | 24篇 |
1995年 | 27篇 |
1994年 | 21篇 |
1993年 | 28篇 |
1992年 | 19篇 |
1991年 | 15篇 |
1990年 | 21篇 |
1989年 | 16篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 8篇 |
1985年 | 15篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 6篇 |
1980年 | 12篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有3101条查询结果,搜索用时 15 毫秒
91.
92.
93.
Adrian J. Harwood Josephine E. Forde-Thomas Hazel Williams Matthias Samereier Annette Müller-Taubenberger 《European journal of cell biology》2013,92(6-7):222-228
Eukaryotic cell division requires the co-ordinated assembly and disassembly of the mitotic spindle, accurate chromosome segregation and temporal control of cytokinesis to generate two daughter cells. While the absolute details of these processes differ between organisms, there are evolutionarily conserved core components common to all eukaryotic cells, whose identification will reveal the key processes that control cell division. Glycogen synthase kinase 3 (GSK-3) is a major protein kinase found throughout the eukaryotes and regulates many processes, including cell differentiation, growth, motility and apoptosis. In animals, GSK-3 associates with mitotic spindles and its inhibition causes mis-regulation of chromosome segregation. Two suppressor screens in yeast point to a more general effect of GSK-3 on cell division, however the direct role of GSK-3 in control of mitosis has not been explored outside the animal kingdom. Here we report that the Dictyostelium discoideum GSK-3 orthologue, GskA, associates with the mitotic spindle during cell division, as seen for its mammalian counterparts. Dictyostelium possesses only a single GSK-3 gene that can be deleted to eliminate all GSK-3 activity. We found that gskA-null mutants failed to elongate their mitotic spindle and were unable to divide in shaking culture, but have no chromosome segregation defect. These results suggest further conservation for the role of GSK-3 in the regulation of spindle dynamics during mitosis, but also reveal differences in the mechanisms ensuring accurate chromosome segregation. 相似文献
94.
Dirk Steinritz Jana Weber Frank Balszuweit Horst Thiermann Annette Schmidt 《Chemico-biological interactions》2013
Sulfur Mustard (SM) is a vesicant chemical warfare agent, which is acutely toxic to a variety of organ systems including skin, eyes, respiratory system and bone marrow. The underlying molecular pathomechanism was mainly attributed to the alkylating properties of SM. However, recent studies have revealed that cellular responses to SM exposure are of more complex nature and include increased protein expression and protein modifications that can be used as biomarkers. In order to confirm already known biomarkers, to detect potential new ones and to further elucidate the pathomechanism of SM, we conducted large-scale proteomic experiments based on a human keratinocyte cell line (HaCaT) exposed to SM. Surprisingly, our analysis identified glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) as one of the up-regulated proteins after exposure of HaCaT cells to SM. In this paper we demonstrate the sulfur mustard induced nuclear translocation of GAPDH in HaCaT cells by 2D gel-electrophoresis (2D GE), immunocytochemistry (ICC), Western Blot (WB) and a combination thereof. 2D GE in combination with MALDI-TOF MS/MS analysis identified GAPDH as an up-regulated protein after SM exposure. Immunocytochemistry revealed a distinct nuclear translocation of GAPDH after exposure to 300 μM SM. This finding was confirmed by fractionated WB analysis. 2D GE and subsequent immunoblot staining of GAPDH demonstrated two different spot locations of GAPH (pI 7.0 and pI 8.5) that are related to cytosolic or nuclear GAPDH respectively. After exposure to 300 μM SM a significant increase of nuclear GAPDH at pI 8.5 occurred. Nuclear GAPDH has been associated with apoptosis, detection of structural DNA alterations, DNA repair and regulation of genomic integrity and telomere structure. The results of our study add new aspects to the pathophysiology of sulfur mustard toxicity, yet further studies will be necessary to reveal the specific function of nuclear GAPDH in the pathomechanism of sulfur mustard. 相似文献
95.
Burcu Kaplan-Türköz Thomas Koelblen Christine Felix Marie-Pierre Candusso David O’Callaghan Annette C. Vergunst Laurent Terradot 《FEBS letters》2013
BtpA/Btp1/TcpB is a virulence factor produced by Brucella species that possesses a Toll interleukin-1 receptor (TIR) domain. Once delivered into the host cell, BtpA interacts with MyD88 to interfere with TLR signalling and modulates microtubule dynamics. Here the crystal structure of the BtpA TIR domain at 3.15 Å is presented. The structure shows a dimeric arrangement of a canonical TIR domain, similar to the Paracoccus denitrificans Tir protein but secured by a unique long N-terminal α-tail that packs against the TIR:TIR dimer. Structure-based mutations and multi-angle light scattering experiments characterized the BtpA dimer conformation in solution. The structure of BtpA will help with studies to understand the mechanisms involved in its interactions with MyD88 and with microtubules. 相似文献
96.
A first approach to discover new antimalarials has been recently performed in a combined approach with data from GlaxoSmithKline Tres Cantos Antimalarial Set, Novartis-GNF Malaria Box Data set and St. Jude Children’s Research Hospital. These data are assembled in the Malaria Box. In a first phenotypic forward chemical genetic approach, 400 chemicals were employed to eradicate the parasite in the erythrocytic stages. The advantage of phenotypic screens for the identification of novel chemotypes is that no a priori assumptions are made concerning a fixed target and that active compounds inherently have cellular bioavailability. In a first screen 40 mostly heterocyclic, highly active compounds (in nmol range of growth inhibition) were identified with EC50 values ≤2 μM against chloroquine-resistant Plasmodium falciparum strains and a therapeutic window ≥10 against two mammalian cell lines. 78 % of the compounds had no violations with the Lipinski Rule of 5 and only 1 % of the compounds showed cytotoxicity when applied at concentrations of 10 μM. This pre-selective step of parasitic eradication will be used further for a test of the Malaria Box with a potential in iron chelating capacity to inhibit deoxyhypusine hydroxylase (DOHH) from P. falciparum and vivax. DOHH, a metalloprotein which consists of ferrous iron and catalyzes the second step of the posttranslational modification at a specific lysine in eukaryotic initiation factor 5A (EIF-5A) to hypusine. Hypusine is a novel, non-proteinogenic amino acid, which is essential in eukaryotes and for parasitic proliferation. DOHH seems to be a “druggable” target, since it has only 26 % amino acid identity to its human orthologue. For a High-throughput Screening (HTS) of DOOH inhibitors, rapid and robust analytical tools are a prerequisite. A proteomic platform for the detection of hypusine metabolites is currently established. Ultra performance Liquid Chromatography enables the detection of hypusine metabolites with retention times of 7.4 min for deoxyhypusine and 7.3 min for hypusine. Alternatively, the analytes can be detected by their masses with gas chromatography/mass spectrometry or one-dimensional chromatography coupled to mass spectrometry. Moreover, the identified hits will be tracked further to test their efficacy in novel “in vitro assays”. Subsequently in vivo inhibition in a humanized mouse model will be tested. 相似文献
97.
Paula Chappell Kirsten Foley Annette B. Jensen William O. H. Hughes 《Ecology and evolution》2013,3(7):2214-2222
Parasites are thought to be a major driving force shaping genetic variation in their host, and are suggested to be a significant reason for the maintenance of sexual reproduction. A leading hypothesis for the occurrence of multiple mating (polyandry) in social insects is that the genetic diversity generated within‐colonies through this behavior promotes disease resistance. This benefit is likely to be particularly significant when colonies are exposed to multiple species and strains of parasites, but host–parasite genotypic interactions in social insects are little known. We investigated this using honey bees, which are naturally polyandrous and consequently produce genetically diverse colonies containing multiple genotypes (patrilines), and which are also known to host multiple strains of various parasite species. We found that host genotypes differed significantly in their resistance to different strains of the obligate fungal parasite that causes chalkbrood disease, while genotypic variation in resistance to the facultative fungal parasite that causes stonebrood disease was less pronounced. Our results show that genetic variation in disease resistance depends in part on the parasite genotype, as well as species, with the latter most likely relating to differences in parasite life history and host–parasite coevolution. Our results suggest that the selection pressure from genetically diverse parasites might be an important driving force in the evolution of polyandry, a mechanism that generates significant genetic diversity in social insects. 相似文献
98.
99.
100.