首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5772篇
  免费   468篇
  国内免费   1篇
  2023年   20篇
  2022年   54篇
  2021年   113篇
  2020年   72篇
  2019年   92篇
  2018年   85篇
  2017年   88篇
  2016年   151篇
  2015年   280篇
  2014年   289篇
  2013年   365篇
  2012年   474篇
  2011年   440篇
  2010年   309篇
  2009年   223篇
  2008年   379篇
  2007年   345篇
  2006年   317篇
  2005年   302篇
  2004年   302篇
  2003年   288篇
  2002年   237篇
  2001年   73篇
  2000年   67篇
  1999年   58篇
  1998年   53篇
  1997年   52篇
  1996年   51篇
  1995年   36篇
  1994年   29篇
  1993年   33篇
  1992年   44篇
  1991年   31篇
  1990年   21篇
  1989年   32篇
  1988年   18篇
  1987年   27篇
  1986年   22篇
  1985年   21篇
  1984年   41篇
  1983年   29篇
  1982年   23篇
  1981年   21篇
  1979年   16篇
  1978年   23篇
  1977年   12篇
  1974年   13篇
  1973年   16篇
  1971年   15篇
  1970年   12篇
排序方式: 共有6241条查询结果,搜索用时 468 毫秒
201.
Introduction: The study of microbial communities based on the combined analysis of genomic and proteomic data – called metaproteogenomics – has gained increased research attention in recent years. This relatively young field aims to elucidate the functional and taxonomic interplay of proteins in microbiomes and its implications on human health and the environment.

Areas covered: This article reviews bioinformatics methods and software tools dedicated to the analysis of data from metaproteomics and metaproteogenomics experiments. In particular, it focuses on the creation of tailored protein sequence databases, on the optimal use of database search algorithms including methods of error rate estimation, and finally on taxonomic and functional annotation of peptide and protein identifications.

Expert opinion: Recently, various promising strategies and software tools have been proposed for handling typical data analysis issues in metaproteomics. However, severe challenges remain that are highlighted and discussed in this article; these include: (i) robust false-positive assessment of peptide and protein identifications, (ii) complex protein inference against a background of highly redundant data, (iii) taxonomic and functional post-processing of identification data, and finally, (iv) the assessment and provision of metrics and tools for quantitative analysis.  相似文献   

202.
Cobamides (Cbas) are essential cofactors of reductive dehalogenases (RDases) in organohalide-respiring bacteria (OHRB). Changes in the Cba structure can influence RDase function. Here, we report on the cofactor versatility or selectivity of Desulfitobacterium RDases produced either in the native organism or heterologously. The susceptibility of Desulfitobacterium hafniense strain DCB-2 to guided Cba biosynthesis (i.e. incorporation of exogenous Cba lower ligand base precursors) was analysed. Exogenous benzimidazoles, azabenzimidazoles and 4,5-dimethylimidazole were incorporated by the organism into Cbas. When the type of Cba changed, no effect on the turnover rate of the 3-chloro-4-hydroxy-phenylacetate-converting enzyme RdhA6 and the 3,5-dichlorophenol-dehalogenating enzyme RdhA3 was observed. The impact of the amendment of Cba lower ligand precursors on RDase function was also investigated in Shimwellia blattae, the Cba producer used for the heterologous production of Desulfitobacterium RDases. The recombinant tetrachloroethene RDase (PceAY51) appeared to be non-selective towards different Cbas. However, the functional production of the 1,2-dichloroethane-dihaloeliminating enzyme (DcaA) of Desulfitobacterium dichloroeliminans was completely prevented in cells producing 5,6-dimethylbenzimidazolyl-Cba, but substantially enhanced in cells that incorporated 5-methoxybenzimidazole into the Cba cofactor. The results of the study indicate the utilization of a range of different Cbas by Desulfitobacterium RDases with selected representatives apparently preferring distinct Cbas.  相似文献   
203.
The International Journal of Life Cycle Assessment - So far, land occupation impact assessment models in life-cycle assessment have predominantly considered biodiversity, ecosystem quality and...  相似文献   
204.
The International Journal of Life Cycle Assessment - Regionalized life cycle impact assessment (LCIA) has rapidly developed in the past decade, though its widespread application, robustness, and...  相似文献   
205.
206.
207.
High-throughput platforms facilitating screening campaigns of environmental samples are needed to discover new products of natural origin counteracting the spreading of antimicrobial resistances constantly threatening human and agricultural health. We applied a combination of droplet microfluidics and fluorescence-activated cell sorting (FACS)-based technologies to access and assess a microbial environmental sample. The cultivation performance of our microfluidics workflow was evaluated in respect to the utilized cultivation media by Illumina amplicon sequencing of a pool of millions of droplets, respectively. This enabled the rational selection of a growth medium supporting the isolation of microbial diversity from soil (five phyla affiliated to 57 genera) including a member of the acidobacterial subgroup 1 (genus Edaphobacter). In a second phase, the entire diversity covered by 1071 cultures was used for an arrayed bioprospecting campaign, resulting in > 6000 extracts tested against human pathogens and agricultural pests. After redundancy curation by using a combinatorial chemical and genomic fingerprinting approach, we assigned the causative agents present in the extracts. Utilizing UHPLC-QTOF-MS/MS-guided fractionation and microplate-based screening assays in combination with molecular networking the production of bioactive ionophorous macrotetrolides, phospholipids, the cyclic lipopetides massetolides E, F, H and serratamolide A and many derivatives thereof was shown.  相似文献   
208.
Statistics in Biosciences - Traditionally, dose-finding process for oncology compound is carried out in phase I dose escalation study and is driven by safety in order to find maximum tolerated dose...  相似文献   
209.
210.
In the developing CNS alpha- and beta-dystroglycan are highly concentrated in the endfeet of radial neuroepithelial cells at the contact site to the basal lamina. We show that injection of anti-dystroglycan Fab fragments, knockdown of dystroglycan using RNAi, and overexpression of a dominant-negative dystroglycan protein by microelectroporation in neuroepithelial cells of the chick retina and optic tectum in vivo leads to the loss of their radial morphology, to hyperproliferation, to an increased number of postmitotic neurons, and to an altered distribution of several basally concentrated proteins. Moreover, these treatments also altered the oriented growth of axons from retinal ganglion cells and from tectal projection neurons. In contrast, expression of non-cleavable dystroglycan protein in neuroepithelial cells reduced their proliferation and their differentiation to postmitotic neurons. These results demonstrate that dystroglycan plays a key role in maintaining neuroepithelial cell morphology, and that interfering with dystroglycan function influences proliferation and differentiation of neuroepithelial cells. These data also suggest that an impaired dystroglycan function in neuroepithelial cells might be responsible for some of the severe brain abnormalities observed in certain forms of congenital muscular dystrophy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号