全文获取类型
收费全文 | 403篇 |
免费 | 35篇 |
专业分类
438篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 14篇 |
2020年 | 3篇 |
2019年 | 9篇 |
2018年 | 15篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 25篇 |
2014年 | 20篇 |
2013年 | 27篇 |
2012年 | 51篇 |
2011年 | 48篇 |
2010年 | 25篇 |
2009年 | 22篇 |
2008年 | 24篇 |
2007年 | 22篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 18篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1984年 | 4篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有438条查询结果,搜索用时 0 毫秒
431.
432.
433.
Binding of p53-derived ligands to MDM2 induces a variety of long range conformational changes 总被引:3,自引:0,他引:3
We have used NMR to study the effects of peptide binding on the N-terminal p53-binding domain of human MDM2 (residues 25-109). There were changes in HSQC-chemical shifts throughout the domain on binding four different p53-derived peptide ligands that were significantly large to be indicative of global conformational changes. Large changes in chemical shift were observed in two main regions: the peptide-binding cleft that directly binds the p53 ligands; and the hinge regions connecting the beta-sheet and alpha-helical structures that form the binding cleft. These conformational changes reflect the adaptation of the cleft on binding peptide ligands that differ in length and amino acid composition. Different ligands may induce different conformational transitions in MDM2 that could be responsible for its function. The dynamic nature of MDM2 might be important in the design of anti-cancer drugs that are targeted to its p53-binding site. 相似文献
434.
A virtual server is a server whose location in an internet is virtual; it may move from one physical site to another, and it may span a dynamically changing number of physical sites. In particular, during periods of high load, it may grow to new machines, while in other times it may shrink into a single host, and may even allow other virtual servers to run on the same host. This paper describes the design and architecture of Symphony, a management infrastructure for executing virtual servers in internet settings. This design is based on combining CORBA technology with group communication capabilities, for added reliability and fault tolerance. 相似文献
435.
436.
Changes in physiological and photosynthetic parameters were followed in the freshwater chorophyte Haematococcus pluvialis Flotow (Volvocales) during the transformation of green vegetative cells to red aplanospores.Formation of aplanospores was induced by exposure to a nitrogen-deficient medium. In spite of an increase in cellular volume (from 6.6 to 41 pL) and amassive accumulation of astaxanthin, chlorophyll content of the mature aplanospore decreased only slightly (from 16 to 14.8 pg'cell?1)as compared to the vegetative cell. Aplanospore formation was characterized by a gradual reduction in the maximal photosynthetic rate and increases in the photosynthetic quantum requirement and minimal turnover time for photosynthetic O2 evolution.Respiration rate increased (4.2 times)and excretion rate decreased (up to 8.8 times) during aplanospore formation. Measurements of photosynthetic unit “size” and estimation of the cellular content of photosystem II reaction centers suggest that the photosynthetic complex remains relatively centers stable during the formation process and in the mature aplanospore.A functional relationship between the describe changes in the physiology of the cells and their photosynthetic parameters is proposed. 相似文献
437.
Studies on enhanced post-illumination respiration in microalgae 总被引:5,自引:0,他引:5
Beardall John; Burger-Wiersma Tineke; Rijkeboer Machteld; Sukenik Assaf; Lemoalle Jacques; Dubinsky Zvy; Fontvielle Daniel 《Journal of plankton research》1994,16(10):1401-1410
The extent of enhanced post-illumination respiration (EPIR)has been investigated in a number of microalgae. Respirationrates, as determined by O2 consumption, were enhanced (in allbut one case) by 50140% following pre-exposure to highphoton flux compared to rates obtained for steady-state darkrespiration. The extent of EPIR was dependent more on photonflux than on duration of exposure, although the latter did havesome effect. In Isochrysis galbana and Chaetoceros calcitrens,EPIR effects were also demonstrated using [14C]CO2 evolution.In I.galbana, release of CO2 from cells pre-exposed to a periodof high photon flux was most rapid from carbohydrate and low-molecular-weightmetabolites. Data obtained from Thalassiosira weisflogii indicatethat cells grown at low photon flux are more susceptible toEPIR than those grown under high photon flux. These resultsare discussed in the context of various hypotheses that havebeen proposed regarding the mechanism of EPIR effects.
8Present address: RIVM-LWD, PO Box 1, 3720 BA Bilthoven, TheNetherlands 相似文献
438.
Hedda Ribolow Kate Bárány Assaf Steinschneider Michael Bárány 《Archives of biochemistry and biophysics》1977,179(1):81-85
The phosphorylation of TN-I was investigated in muscles of live frogs injected with [32P]orthophosphate. Isolation of TN-I was carried out by the rapid and specific technique of affinity chromatography developed by Syska, Perry, and Trayer [FEBS Lett.40, 253–257 (1974)] followed by gel electrophoresis in the presence of sodium dodecyl sulfate. No significant labeling of TN-I was found even in frogs which were exposed to the 32P-treatment for several days. A comparison of the specific radioactivity of TN-I from resting and contracting frog muscle showed no change in the 32P content of TN-I during muscle contraction. 相似文献