全文获取类型
收费全文 | 1355篇 |
免费 | 122篇 |
出版年
2023年 | 12篇 |
2022年 | 13篇 |
2021年 | 40篇 |
2020年 | 29篇 |
2019年 | 37篇 |
2018年 | 25篇 |
2017年 | 29篇 |
2016年 | 46篇 |
2015年 | 80篇 |
2014年 | 86篇 |
2013年 | 81篇 |
2012年 | 147篇 |
2011年 | 100篇 |
2010年 | 56篇 |
2009年 | 47篇 |
2008年 | 52篇 |
2007年 | 60篇 |
2006年 | 46篇 |
2005年 | 46篇 |
2004年 | 33篇 |
2003年 | 34篇 |
2002年 | 29篇 |
2001年 | 29篇 |
2000年 | 22篇 |
1999年 | 15篇 |
1998年 | 12篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 10篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 16篇 |
1991年 | 13篇 |
1990年 | 16篇 |
1989年 | 15篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1981年 | 5篇 |
1977年 | 5篇 |
1971年 | 9篇 |
1967年 | 4篇 |
1887年 | 6篇 |
1886年 | 6篇 |
1885年 | 8篇 |
1883年 | 8篇 |
1882年 | 4篇 |
1875年 | 6篇 |
排序方式: 共有1477条查询结果,搜索用时 31 毫秒
111.
112.
Auxotrophy and intrapopulation complementary in the ‘interactome’ of a cultivated freshwater model community
下载免费PDF全文
![点击此处可从《Molecular ecology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sarahi L. Garcia Moritz Buck Katherine D. McMahon Hans‐Peter Grossart Alexander Eiler Falk Warnecke 《Molecular ecology》2015,24(17):4449-4459
Microorganisms are usually studied either in highly complex natural communities or in isolation as monoclonal model populations that we manage to grow in the laboratory. Here, we uncover the biology of some of the most common and yet‐uncultured bacteria in freshwater environments using a mixed culture from Lake Grosse Fuchskuhle. From a single shotgun metagenome of a freshwater mixed culture of low complexity, we recovered four high‐quality metagenome‐assembled genomes (MAGs) for metabolic reconstruction. This analysis revealed the metabolic interconnectedness and niche partitioning of these naturally dominant bacteria. In particular, vitamin‐ and amino acid biosynthetic pathways were distributed unequally with a member of Crenarchaeota most likely being the sole producer of vitamin B12 in the mixed culture. Using coverage‐based partitioning of the genes recovered from a single MAG intrapopulation metabolic complementarity was revealed pointing to ‘social’ interactions for the common good of populations dominating freshwater plankton. As such, our MAGs highlight the power of mixed cultures to extract naturally occurring ‘interactomes’ and to overcome our inability to isolate and grow the microbes dominating in nature. 相似文献
113.
114.
Raimondi A Ferguson SM Lou X Armbruster M Paradise S Giovedi S Messa M Kono N Takasaki J Cappello V O'Toole E Ryan TA De Camilli P 《Neuron》2011,70(6):1100-1114
The existence of neuron-specific endocytic protein isoforms raises questions about their importance for specialized neuronal functions. Dynamin, a GTPase implicated in the fission reaction of endocytosis, is encoded by three genes, two of which, dynamin 1 and 3, are highly expressed in neurons. We show that dynamin 3, thought to play a predominantly postsynaptic role, has a major presynaptic function. Although lack of dynamin 3 does not produce an overt phenotype in mice, it worsens the dynamin 1 KO phenotype, leading to perinatal lethality and a more severe defect in activity-dependent synaptic vesicle endocytosis. Thus, dynamin 1 and 3, which together account for the overwhelming majority of brain dynamin, cooperate in supporting optimal rates of synaptic vesicle endocytosis. Persistence of synaptic transmission in their absence indicates that if dynamin plays essential functions in neurons, such functions can be achieved by the very low levels of dynamin 2. 相似文献
115.
In Daphnia (Cladocera, Crustacea), parthenogenetic reproduction alternates with sexual reproduction. Individuals of both sexes that belong to the same parthenogenetic line are genetically identical, and their sex is determined by the environment. Previously, non-male producing (NMP) genotypes have been described in species of the Daphnia pulex group. Such genotypes can only persist through phases of sexual reproduction if they co-occur with normal (MP) genotypes that produce both males and females, and thus the breeding system polymorphism is similar to gynodioecy (coexistence of females with hermaphrodites), which is well known in plants. Here we show that the same breeding system polymorphism also occurs in Daphnia magna, a species that has diverged from D. pulex more than 100 MY ago. Depending on the population, between 0% and 40% of D. magna females do not produce males when experimentally exposed to a concentration of the putative sex hormone methyl farnesoate that normally leads to male-only clutches. Natural broods of these NMP females never contained males, contrasting with high proportions of male offspring in MP females from the same populations. The results from a series of crossing experiments suggest that NMP is determined by a dominant allele at a single nuclear locus (or a several closely linked loci): NMP × MP crosses always yielded 50% NMP and 50% MP offspring, whereas MP × MP crosses always yielded 100% MP offspring. Based on cytochrome c oxidase subunit I-sequences, we found that NMP genotypes from different populations belong to three highly divergent mitochondrial lineages, potentially representing three independent evolutionary origins of NMP in D. magna. Thus, the evolution of NMP genotypes in cyclical parthenogens may be more common than previously thought. Moreover, MP genotypes that coexist with NMP genotypes may have responded to the presence of the latter by partially specializing on male production. Hence, these populations of D. magna may be a model for an evolutionary transition from a purely environmental to a partially genetic sex determination system. 相似文献
116.
Madsen RK Lundstedt T Gabrielsson J Sennbro CJ Alenius GM Moritz T Rantapää-Dahlqvist S Trygg J 《Arthritis research & therapy》2011,13(1):R19
Introduction
The aim of this study was to assess the feasibility of diagnosing early rheumatoid arthritis (RA) by measuring selected metabolic biomarkers. 相似文献117.
Mi-Youn K Brusniak Sung-Tat Kwok Mark Christiansen David Campbell Lukas Reiter Paola Picotti Ulrike Kusebauch Hector Ramos Eric W Deutsch Jingchun Chen Robert L Moritz Ruedi Aebersold 《BMC bioinformatics》2011,12(1):1-15
Background
Copy number variants (CNVs), including deletions, amplifications, and other rearrangements, are common in human and cancer genomes. Copy number data from array comparative genome hybridization (aCGH) and next-generation DNA sequencing is widely used to measure copy number variants. Comparison of copy number data from multiple individuals reveals recurrent variants. Typically, the interior of a recurrent CNV is examined for genes or other loci associated with a phenotype. However, in some cases, such as gene truncations and fusion genes, the target of variant lies at the boundary of the variant.Results
We introduce Neighborhood Breakpoint Conservation (NBC), an algorithm for identifying rearrangement breakpoints that are highly conserved at the same locus in multiple individuals. NBC detects recurrent breakpoints at varying levels of resolution, including breakpoints whose location is exactly conserved and breakpoints whose location varies within a gene. NBC also identifies pairs of recurrent breakpoints such as those that result from fusion genes. We apply NBC to aCGH data from 36 primary prostate tumors and identify 12 novel rearrangements, one of which is the well-known TMPRSS2-ERG fusion gene. We also apply NBC to 227 glioblastoma tumors and predict 93 novel rearrangements which we further classify as gene truncations, germline structural variants, and fusion genes. A number of these variants involve the protein phosphatase PTPN12 suggesting that deregulation of PTPN12, via a variety of rearrangements, is common in glioblastoma.Conclusions
We demonstrate that NBC is useful for detection of recurrent breakpoints resulting from copy number variants or other structural variants, and in particular identifies recurrent breakpoints that result in gene truncations or fusion genes. Software is available at http://http.//cs.brown.edu/people/braphael/software.html. 相似文献118.
Van Campenhout CA Eitelhuber A Gloeckner CJ Giallonardo P Gegg M Oller H Grant SG Krappmann D Ueffing M Lickert H 《Developmental cell》2011,21(3):479-491
The Drosophila Discs large (Dlg) scaffolding protein acts as a tumor suppressor regulating basolateral epithelial polarity and proliferation. In mammals, four Dlg homologs have been identified; however, their functions in cell polarity remain poorly understood. Here, we demonstrate that the X-linked mental retardation gene product Dlg3 contributes to apical-basal polarity and epithelial junction formation in mouse organizer tissues, as well as to planar cell polarity in the inner ear. We purified complexes associated with Dlg3 in polarized epithelial cells, including proteins regulating directed trafficking and tight junction formation. Remarkably, of the four Dlg family members, Dlg3 exerts a distinct function by recruiting the ubiquitin ligases Nedd4 and Nedd4-2 through its PPxY motifs. We found that these interactions are required for Dlg3 monoubiquitination, apical membrane recruitment, and tight junction consolidation. Our findings reveal an unexpected evolutionary diversification of the vertebrate Dlg family in basolateral epithelium formation. 相似文献
119.
120.
Miao Lin Kenji Chamoto Barry C Gibney Grace S Lee Dinee Collings-Simpson Jan Houdek Moritz A Konerding Akira Tsuda Steven J Mentzer 《Respiratory research》2011,12(1):1-11