全文获取类型
收费全文 | 1625篇 |
免费 | 133篇 |
出版年
2023年 | 8篇 |
2022年 | 20篇 |
2021年 | 40篇 |
2020年 | 19篇 |
2019年 | 25篇 |
2018年 | 26篇 |
2017年 | 33篇 |
2016年 | 51篇 |
2015年 | 74篇 |
2014年 | 101篇 |
2013年 | 101篇 |
2012年 | 143篇 |
2011年 | 126篇 |
2010年 | 85篇 |
2009年 | 75篇 |
2008年 | 120篇 |
2007年 | 125篇 |
2006年 | 108篇 |
2005年 | 90篇 |
2004年 | 125篇 |
2003年 | 94篇 |
2002年 | 79篇 |
2001年 | 10篇 |
2000年 | 12篇 |
1999年 | 17篇 |
1998年 | 16篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有1758条查询结果,搜索用时 468 毫秒
1.
2.
3.
Keven D. Juaire Karine Lapouge Matthias M.M. Becker Irina Kotova Michelle Michelhans Raphael Carapito Klemens Wild Seiamak Bahram Irmgard Sinning 《Structure (London, England : 1993)》2021,29(1):15-28.e7
- Download : Download high-res image (235KB)
- Download : Download full-size image
4.
Philippe Lejeune Philippe Bertin Corinne Walon Karine Willemot Charles Colson Antoine Danchin 《Molecular & general genetics : MGG》1989,218(2):361-363
Summary Spontaneous mutants of Escherichia coli K12 displaying an increased level of the kanamycin resistance conferred by plasmid pGR71 were selected. Several mutants obtained in this way apparently carry large chromosomal deletions extending into galU and/or bglY (27 min). This positive selection of deletions allowed detection of a new locus located between galU and bglY. Deletions of this locus are responsible for increased resistance to kanamycin (Irk), decreased resistance to l-serine in minimal medium (Drs) and decreased resistance to chloramphenicol (Drc) when a cat gene is present in the bacteria. 相似文献
5.
Identification and expression of water stress- and abscisic acid-regulated genes in a drought-tolerant sunflower genotype 总被引:17,自引:0,他引:17
6.
Karine Cahier Damien Piel Rubén Barcia-Cruz David Goudenège K. Mathias Wegner Marc Monot Jesús L. Romalde Frédérique Le Roux 《Environmental microbiology》2023,25(8):1424-1438
Phages depend on their bacterial hosts to replicate. The habitat, density and genetic diversity of host populations are therefore key factors in phage ecology, but our ability to explore their biology depends on the isolation of a diverse and representative collection of phages from different sources. Here, we compared two populations of marine bacterial hosts and their phages collected during a time series sampling program in an oyster farm. The population of Vibrio crassostreae, a species associated specifically to oysters, was genetically structured into clades of near clonal strains, leading to the isolation of closely related phages forming large modules in phage–bacterial infection networks. For Vibrio chagasii, which blooms in the water column, a lower number of closely related hosts and a higher diversity of isolated phages resulted in small modules in the phage–bacterial infection network. Over time, phage load was correlated with V. chagasii abundance, indicating a role of host blooms in driving phage abundance. Genetic experiments further demonstrated that these phage blooms can generate epigenetic and genetic variability that can counteract host defence systems. These results highlight the importance of considering both the environmental dynamics and the genetic structure of the host when interpreting phage–bacteria networks. 相似文献
7.
Escherichia coli Heat Shock Protein DnaK: Production and Consequences in Terms of Monitoring Cooking
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Karine Seyer Martin Lessard Gabriel Piette Monique Lacroix Linda Saucier 《Applied microbiology》2003,69(6):3231-3237
Through use of commercially available DnaK proteins and anti-DnaK monoclonal antibodies, a competitive enzyme-linked immunosorbent assay was developed to quantify this heat shock protein in Escherichia coli ATCC 25922 subjected to various heating regimens. For a given process lethality (F7010 of 1, 3, and 5 min), the intracellular concentration of DnaK in E. coli varied with the heating temperature (50 or 55°C). In fact, the highest DnaK concentrations were found after treatments at the lower temperature (50°C) applied for a longer time. Residual DnaK after heating was found to be necessary for cell recovery, and additional DnaK was produced during the recovery process. Overall, higher intracellular concentrations of DnaK tended to enhance cell resistance to a subsequent lethal stress. Indeed, E. coli cells that had undergone a sublethal heat shock (105 min at 55°C, F7010 = 3 min) accompanied by a 12-h recovery (containing 76,786 ± 25,230 molecules/cell) resisted better than exponentially growing cells (38,500 ± 6,056 molecules/cell) when later heated to 60°C for 50 min (F7010 = 5 min). Results reported here suggest that using stress protein to determine cell adaptation and survival, rather than cell counts alone, may lead to more efficient heat treatment. 相似文献
8.
Plasmidial maintenance in rodent fibroblasts of a BPV1-pBR322 shuttle vector without immediately apparent oncogenic transformation of the recipient cells. 总被引:8,自引:2,他引:6
下载免费PDF全文
![点击此处可从《The EMBO journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A recombinant plasmid was constructed (pV69) which comprises a subgenomic fragment of bovine papilloma virus type 1 (BPV1) DNA, part of plasmid pBR322 DNA and a drug resistance gene expressed in both mammalian fibroblasts and Escherichia coli. This gene (vv2) is a modified form of the bacterial neomycin resistance gene (neo) linked to the herpes simplex virus thymidine kinase (tk) promoter (plasmid pAG60), to which the original bacterial neo promoter from transposon Tn5 was added back, upstream of the eukaryotic promoter. It induced kanamycin resistance in E. coli, as well as resistance to the drug G418 in rat and mouse fibroblasts. Its expression in FR3T3 rat cells was enhanced as compared with the original tk-neo construction. After transfer of plasmid pV69 into C127 mouse cells or FR3T3 rat cells, the number of resistant colonies selected in medium containing G418 was one to two orders of magnitude higher than that of transformed foci in normal medium. In eight independent cell lines selected by drug resistance, pV69 DNA was found to be maintained in a plasmidial state, without any detectable rearrangement or deletion and could be transferred back in E. coli. In contrast, cell lines selected by focus formation in normal medium maintained deleted forms of the original plasmid DNA, and only part of them were resistant to G418. Most of the drug-resistant clones had kept the morphology and growth control of the normal fibroblasts. However, with further passages in culture, these cells spontaneously produced transformed foci with increasing frequencies. 相似文献
9.
Arques Didier G.; Michel Christian J.; Orieux Karine 《Bioinformatics (Oxford, England)》1992,8(1):5-14
The software AGE (Analysis of Gene Evolution) has been developedboth to study a genetic reality, i. e. the identification ofstatistical properties in genes (e.g. periodicities), and tosimulate this observed genetic reality, by models of molecularevolution. AGE has two types of models: (i) models of sequencecreation from oligonucleotides: concatenation model in seriesof an oligonucleotide, independent (or Markov) mixing modelof oligonucleotides according to given probabilities (or a Markovmatrix); (ii) models of sequence evolution from created sequences:insertion/deletion process of (mono, di, tri)nucleot-ides, basemutation process. The study of a reality and the developmentof simulation models are based on several new algorithms: approximatedsimulation and exact calculus to compute various autocorrelationfunctions, Fourier transformation of autocorrelation curves,recognition of a curve form, etc. AGE is implemented on IBMor compatible microcomputers and can be used by biologists withoutany computer knowledge to identify statistical properties intheir newly determined DNA sequence and to explain them by modelsof molecular evolution. 相似文献
10.
Maryse Bourgault Heidi A. Webber Karine Chenu Garry J. OLeary Thomas Gaiser Stefan Siebert Fernanda Dreccer Neil Huth Glenn J. Fitzgerald Michael Tausz Frank Ewert 《Global Change Biology》2020,26(7):4079-4093
Early vigour in wheat is a trait that has received attention for its benefits reducing evaporation from the soil surface early in the season. However, with the growth enhancement common to crops grown under elevated atmospheric CO2 concentrations (e[CO2]), there is a risk that too much early growth might deplete soil water and lead to more severe terminal drought stress in environments where production relies on stored soil water content. If this is the case, the incorporation of such a trait in wheat breeding programmes might have unintended negative consequences in the future, especially in dry years. We used selected data from cultivars with proven expression of high and low early vigour from the Australian Grains Free Air CO2 Enrichment (AGFACE) facility, and complemented this analysis with simulation results from two crop growth models which differ in the modelling of leaf area development and crop water use. Grain yield responses to e[CO2] were lower in the high early vigour group compared to the low early vigour group, and although these differences were not significant, they were corroborated by simulation model results. However, the simulated lower response with high early vigour lines was not caused by an earlier or greater depletion of soil water under e[CO2] and the mechanisms responsible appear to be related to an earlier saturation of the radiation intercepted. Whether this is the case in the field needs to be further investigated. In addition, there was some evidence that the timing of the drought stress during crop growth influenced the effect of e[CO2] regardless of the early vigour trait. There is a need for FACE investigations of the value of traits for drought adaptation to be conducted under more severe drought conditions and variable timing of drought stress, a risky but necessary endeavour. 相似文献