全文获取类型
收费全文 | 7650篇 |
免费 | 874篇 |
国内免费 | 3篇 |
出版年
2021年 | 103篇 |
2019年 | 58篇 |
2018年 | 87篇 |
2017年 | 94篇 |
2016年 | 121篇 |
2015年 | 178篇 |
2014年 | 236篇 |
2013年 | 336篇 |
2012年 | 352篇 |
2011年 | 352篇 |
2010年 | 241篇 |
2009年 | 193篇 |
2008年 | 276篇 |
2007年 | 318篇 |
2006年 | 292篇 |
2005年 | 274篇 |
2004年 | 253篇 |
2003年 | 252篇 |
2002年 | 236篇 |
2001年 | 193篇 |
2000年 | 217篇 |
1999年 | 178篇 |
1998年 | 117篇 |
1997年 | 90篇 |
1996年 | 89篇 |
1995年 | 77篇 |
1994年 | 69篇 |
1993年 | 81篇 |
1992年 | 150篇 |
1991年 | 132篇 |
1990年 | 125篇 |
1989年 | 127篇 |
1988年 | 128篇 |
1987年 | 154篇 |
1986年 | 136篇 |
1985年 | 133篇 |
1984年 | 151篇 |
1983年 | 150篇 |
1982年 | 103篇 |
1981年 | 120篇 |
1980年 | 113篇 |
1979年 | 115篇 |
1978年 | 79篇 |
1977年 | 71篇 |
1976年 | 78篇 |
1975年 | 62篇 |
1974年 | 81篇 |
1973年 | 70篇 |
1970年 | 49篇 |
1969年 | 53篇 |
排序方式: 共有8527条查询结果,搜索用时 15 毫秒
981.
982.
983.
Detection of Enterobacter sakazakii in Dried Infant Milk Formula by Cationic-Magnetic-Bead Capture 总被引:1,自引:0,他引:1
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)
N. R. Mullane J. Murray D. Drudy N. Prentice P. Whyte P. G. Wall A. Parton S. Fanning 《Applied microbiology》2006,72(9):6325-6330
Enterobacter sakazakii has been associated with life-threatening infections in premature low-birth-weight infants. Contaminated infant milk formula (IMF) has been implicated in cases of E. sakazakii meningitis. Quick and sensitive methods to detect low-level contamination sporadically present in IMF preparations would positively contribute towards risk reduction across the infant formula food chain. Here we report on the development of a simple method, combining charged separation and growth on selective agar, to detect E. sakazakii in IMF. This protocol can reliably detect 1 to 5 CFU of E. sakazakii in 500 g of IMF in less than 24 h. 相似文献
984.
Diversity and Distribution of Planctomycetes and Related Bacteria in the Suboxic Zone of the Black Sea 总被引:2,自引:1,他引:1
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)
John Kirkpatrick Brian Oakley Clara Fuchsman Sujatha Srinivasan James T. Staley James W. Murray 《Applied microbiology》2006,72(4):3079-3083
Samples from six depths of the Black Sea's suboxic zone were analyzed for 16S rRNA gene sequence information. A gradient in phylotype diversity was found. The distributions of known anaerobic ammonium oxidation (anammox) bacteria, many unknown Planctomycetes, and other phylotypes were examined in relation to the local nutrient and redox conditions. 相似文献
985.
986.
987.
Apoptosis of vascular smooth muscle cells induces features of plaque vulnerability in atherosclerosis 总被引:8,自引:0,他引:8
Clarke MC Figg N Maguire JJ Davenport AP Goddard M Littlewood TD Bennett MR 《Nature medicine》2006,12(9):1075-1080
Vascular smooth muscle cell (VSMC) apoptosis occurs in many arterial diseases, including aneurysm formation, angioplasty restenosis and atherosclerosis. Although VSMC apoptosis promotes vessel remodeling, coagulation and inflammation, its precise contribution to these diseases is unknown, given that apoptosis frequently accompanies vessel injury or alterations to flow. To study the direct consequences of VSMC apoptosis, we generated transgenic mice expressing the human diphtheria toxin receptor (hDTR, encoded by HBEGF) from a minimal Tagln (also known as SM22alpha) promoter. Despite apoptosis inducing loss of 50-70% of VSMCs, normal arteries showed no inflammation, reactive proliferation, thrombosis, remodeling or aneurysm formation. In contrast, VSMC apoptosis in atherosclerotic plaques of SM22alpha-hDTR Apoe-/- mice induced marked thinning of fibrous cap, loss of collagen and matrix, accumulation of cell debris and intense intimal inflammation. We conclude that VSMC apoptosis is 'silent' in normal arteries, which have a large capacity to withstand cell loss. In contrast, VSMC apoptosis alone is sufficient to induce features of plaque vulnerability in atherosclerosis. SM22alpha-hDTR Apoe-/- mice may represent an important new model to test agents proposed to stabilize atherosclerotic plaques. 相似文献
988.
Thomson M Herbert JF Thompson MB 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2006,144(3):382-386
Plastic changes occur in the morphology of the uterus at various stages of the reproductive cycle in both oviparous and viviparous lizards and these may be influenced by estrogen. Estrogen driven phosphorylation of effector proteins on tyrosine residues plays a major role in the plastic modulation of uterine anatomy and physiology in vertebrates. We used electrophoresis and Western blotting to characterize the phosphotyrosine protein profiles at various stages of the reproductive pathway in an oviparous lizard Lampropholis guichenoti and a viviparous lizard Eulamprus tympanum. L. guichenoti displayed major bands in the 200-35 kDa range and a triplet of bands of molecular masses 61 kDa, 52 kDa and 48 kDa in 50% of specimens and a 38 kDa band in all specimens. In contrast, E. tympanum samples all displayed a single major band at 40 kDa, which was significantly elevated at the early pregnancy stage. Somewhat paradoxically, the viviparous species, which has the more complex uterine epithelial changes during pregnancy, has the fewest phosphotyrosine bands, so how tyrosine phosphorylation is affected during the evolution of viviparity is not clear. 相似文献
989.
990.
The plant embryo is a relatively simple structure consisting of a primordial shoot and root, whose development is frozen in the form of a seed. Most development of the mature plant takes place post-embryonically, and is the consequence of cell division and organogenesis in small regions known as meristems, which originate in the embryonic shoot and root apices. Significant recent progress has been made in understanding the mechanisms that control the plant cell cycle at a molecular level, and the first attempts have been made to control plant growth through modulation of cell-cycle genes. These results suggest that there is significant potential to control plant growth and architecture through manipulation of cell division rates. However, a full realisation of the promise of such strategies will probably require a much greater understanding of cell division control and how its upstream regulation is co-ordinated by spatial relationships between cells and by environmental signals. 相似文献