全文获取类型
收费全文 | 814篇 |
免费 | 117篇 |
出版年
2022年 | 5篇 |
2021年 | 16篇 |
2020年 | 5篇 |
2018年 | 12篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 29篇 |
2014年 | 26篇 |
2013年 | 34篇 |
2012年 | 38篇 |
2011年 | 45篇 |
2010年 | 25篇 |
2009年 | 27篇 |
2008年 | 36篇 |
2007年 | 41篇 |
2006年 | 33篇 |
2005年 | 24篇 |
2004年 | 45篇 |
2003年 | 32篇 |
2002年 | 34篇 |
2001年 | 34篇 |
2000年 | 43篇 |
1999年 | 20篇 |
1998年 | 16篇 |
1997年 | 18篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 10篇 |
1992年 | 16篇 |
1991年 | 10篇 |
1990年 | 13篇 |
1989年 | 12篇 |
1988年 | 15篇 |
1987年 | 14篇 |
1986年 | 12篇 |
1985年 | 14篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 13篇 |
1980年 | 10篇 |
1978年 | 14篇 |
1977年 | 6篇 |
1976年 | 10篇 |
1975年 | 5篇 |
1973年 | 6篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1967年 | 5篇 |
排序方式: 共有931条查询结果,搜索用时 171 毫秒
721.
Thurlough O. Criodain Michael OSullivan Mary Jane Meegan Dervilla M.X. Donnelly 《Phytochemistry》1981,20(5):1089-1092
Latinone, a substituted phenanthrene-1,4-quinone was isolated from Dalbergia latifolia. The structure was assigned from spectroscopic measurements and a synthesis was carried out using a Diels-Alder reaction to form the ring structure. 相似文献
722.
Swe1Wee1-Dependent Tyrosine Phosphorylation of Hsp90 Regulates Distinct Facets of Chaperone Function
Mehdi Mollapour Shinji Tsutsumi Alison C. Donnelly Kristin Beebe Mari J. Tokita Min-Jung Lee Sunmin Lee Giulia Morra Dimitra Bourboulia Bradley T. Scroggins Giorgio Colombo Brian S. Blagg Barry Panaretou William G. Stetler-Stevenson Jane B. Trepel Peter W. Piper Chrisostomos Prodromou Laurence H. Pearl Len Neckers 《Molecular cell》2010,37(3):333-343
723.
The uptake of fatty acids by the liver was shown previously to be a non-catalyzed process, and rates of uptake were correlated to the affinity of the plasma membranes of liver cells for fatty acids. The experiments in this paper were designed to test whether the known differences in uptake and metabolism of free fatty acids by the livers of male and female rats could be understood based on differences in the affinities of the corresponding plasma membranes for these substrates. The relative affinities for palmitate and oleate of 'male' plasma membranes were found to be lower versus 'female' membranes. Measurements of uptake of palmitate from albumin-palmitate complexes by 'male' and 'female' perfused livers showed higher uptake rates by the latter when correlated with the concentration of the complex. However, the rates of uptake were identical when the concentrations of the fatty acid in the plasma membranes of male and female liver cells were the same. 相似文献
724.
Dyer NA Ravel S Choi KS Darby AC Causse S Kapitano B Hall MJ Steen K Lutumba P Madinga J Torr SJ Okedi LM Lehane MJ Donnelly MJ 《PLoS neglected tropical diseases》2011,5(8):e1266
Background
The tsetse fly Glossina fuscipes s.l. is responsible for the transmission of approximately 90% of cases of human African trypanosomiasis (HAT) or sleeping sickness. Three G. fuscipes subspecies have been described, primarily based upon subtle differences in the morphology of their genitalia. Here we describe a study conducted across the range of this important vector to determine whether molecular evidence generated from nuclear DNA (microsatellites and gene sequence information), mitochondrial DNA and symbiont DNA support the existence of these taxa as discrete taxonomic units.Principal Findings
The nuclear ribosomal Internal transcribed spacer 1 (ITS1) provided support for the three subspecies. However nuclear and mitochondrial sequence data did not support the monophyly of the morphological subspecies G. f. fuscipes or G. f. quanzensis. Instead, the most strongly supported monophyletic group was comprised of flies sampled from Ethiopia. Maternally inherited loci (mtDNA and symbiont) also suggested monophyly of a group from Lake Victoria basin and Tanzania, but this group was not supported by nuclear loci, suggesting different histories of these markers. Microsatellite data confirmed strong structuring across the range of G. fuscipes s.l., and was useful for deriving the interrelationship of closely related populations.Conclusion/Significance
We propose that the morphological classification alone is not used to classify populations of G. fuscipes for control purposes. The Ethiopian population, which is scheduled to be the target of a sterile insect release (SIT) programme, was notably discrete. From a programmatic perspective this may be both positive, given that it may reflect limited migration into the area or negative if the high levels of differentiation are also reflected in reproductive isolation between this population and the flies to be used in the release programme. 相似文献725.
726.
Adam S. Fisch Laura M. Yerges-Armstrong Joshua D. Backman Hong Wang Patrick Donnelly Kathleen A. Ryan Ankita Parihar Mary A. Pavlovich Braxton D. Mitchell Jeffrey R. O’Connell William Herzog Christopher R. Harman Jonathan D. Wren Joshua P. Lewis 《PloS one》2015,10(9)
Platelet Endothelial Aggregation Receptor 1 (PEAR1) is a newly identified membrane protein reported to be involved in multiple vascular and thrombotic processes. While most studies to date have focused on the effects of this receptor in platelets, PEAR1 is located in multiple tissues including the endothelium, where it is most highly expressed. Our first objective was to evaluate the role of PEAR1 in endothelial function by examining flow-mediated dilation of the brachial artery in 641 participants from the Heredity and Phenotype Intervention Heart Study. Our second objective was to further define the impact of PEAR1 on cardiovascular disease computationally through meta-analysis of 75,000 microarrays, yielding insights regarding PEAR1 function, and predictions of phenotypes and diseases affected by PEAR1 dysregulation. Based on the results of this meta-analysis we examined whether genetic variation in PEAR1 influences endothelial function using an ex vivo assay of endothelial cell migration. We observed a significant association between rs12041331 and flow-mediated dilation in participants of the Heredity and Phenotype Intervention Heart Study (P = 0.02). Meta-analysis results revealed that PEAR1 expression is highly correlated with several genes (e.g. ANG2, ACVRL1, ENG) and phenotypes (e.g. endothelial cell migration, angiogenesis) that are integral to endothelial function. Functional validation of these results revealed that PEAR1 rs12041331 is significantly associated with endothelial migration (P = 0.04). Our results suggest for the first time that genetic variation of PEAR1 is a significant determinant of endothelial function through pathways implicated in cardiovascular disease. 相似文献
727.
Danilo O. Carvalho Andrew R. McKemey Luiza Garziera Renaud Lacroix Christl A. Donnelly Luke Alphey Aldo Malavasi Margareth L. Capurro 《PLoS neglected tropical diseases》2015,9(7)
The increasing burden of dengue, and the relative failure of traditional vector control programs highlight the need to develop new control methods. SIT using self-limiting genetic technology is one such promising method. A self-limiting strain of Aedes aegypti, OX513A, has already reached the stage of field evaluation. Sustained releases of OX513A Ae. aegypti males led to 80% suppression of a target wild Ae. aegypti population in the Cayman Islands in 2010. Here we describe sustained series of field releases of OX513A Ae. aegypti males in a suburb of Juazeiro, Bahia, Brazil. This study spanned over a year and reduced the local Ae. aegypti population by 95% (95% CI: 92.2%-97.5%) based on adult trap data and 81% (95% CI: 74.9-85.2%) based on ovitrap indices compared to the adjacent no-release control area. The mating competitiveness of the released males (0.031; 95% CI: 0.025-0.036) was similar to that estimated in the Cayman trials (0.059; 95% CI: 0.011 – 0.210), indicating that environmental and target-strain differences had little impact on the mating success of the OX513A males. We conclude that sustained release of OX513A males may be an effective and widely useful method for suppression of the key dengue vector Ae. aegypti. The observed level of suppression would likely be sufficient to prevent dengue epidemics in the locality tested and other areas with similar or lower transmission. 相似文献
728.
729.
Kelly A. Fimlaid Owen Jensen M. Lauren Donnelly Michael B. Francis Joseph A. Sorg Aimee Shen 《PLoS pathogens》2015,11(10)
Clostridium difficile is a Gram-positive spore-forming pathogen and a leading cause of nosocomial diarrhea. C. difficile infections are transmitted when ingested spores germinate in the gastrointestinal tract and transform into vegetative cells. Germination begins when the germinant receptor CspC detects bile salts in the gut. CspC is a subtilisin-like serine pseudoprotease that activates the related CspB serine protease through an unknown mechanism. Activated CspB cleaves the pro-SleC zymogen, which allows the activated SleC cortex hydrolase to degrade the protective cortex layer. While these regulators are essential for C. difficile spores to outgrow and form toxin-secreting vegetative cells, the mechanisms controlling their function have only been partially characterized. In this study, we identify the lipoprotein GerS as a novel regulator of C. difficile spore germination using targeted mutagenesis. A gerS mutant has a severe germination defect and fails to degrade cortex even though it processes SleC at wildtype levels. Using complementation analyses, we demonstrate that GerS secretion, but not lipidation, is necessary for GerS to activate SleC. Importantly, loss of GerS attenuates the virulence of C. difficile in a hamster model of infection. Since GerS appears to be conserved exclusively in related Peptostreptococcaeace family members, our results contribute to a growing body of work indicating that C. difficile has evolved distinct mechanisms for controlling the exit from dormancy relative to B. subtilis and other spore-forming organisms. 相似文献
730.
Asha Tukappa NK Ramesh L Londonkar Hanumantappa B Nayaka Sanjeev Kumar CB 《Biological research》2015,48(1)