全文获取类型
收费全文 | 280篇 |
免费 | 17篇 |
出版年
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 10篇 |
2017年 | 3篇 |
2016年 | 14篇 |
2015年 | 7篇 |
2014年 | 16篇 |
2013年 | 16篇 |
2012年 | 29篇 |
2011年 | 13篇 |
2010年 | 9篇 |
2009年 | 15篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 10篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有297条查询结果,搜索用时 15 毫秒
291.
R. Rein S. Srinivasan J. McDonald G. Raghunathan M. Shibata 《Origins of life and evolution of the biosphere》1987,17(3-4):431-438
The molecular mechanisms underlying the primitive translational apparatus have been studied in light of present day protein
biosynthesis. Using the structural information available from the contemporary system as a key to its function, both the structural
necessities for an early adaptor and the multipoint recognition properties of such adaptors have been investigated. This was
done by first critically examining the potential feasibility of right- and left-handed hairpin adaptor models. Second, a molecular
model of the contemporary transpeptidation complex has been constructed in order to ascertain the structural requirements
of the adaptor molecule needed for peptidyl transfer. Third, a model of the tRNATyr-tyrosyl tRNA synthetase complex including the positioning of the disordered region is proposed. This model is used to illustrate
those required recognition properties of aminoacyl synthetase which lead to a perspective on the structure of the ancestor
synthetase. 相似文献
292.
The effect on the structure of profilin of phosphatidylinositol 4,5-bisphosphate (PIP2) binding was probed by fluorescence and circular dichroism (CD) spectroscopy. Fluorescence of Trp3 and Trp31 of profilin at 292 nm showed a linear decrease in solution emission at 340 nm as PIP2/profilin was increased from 0 to 80:1, apparently due to a static quenching mechanism involving formation of a nonfluorescent PIP2/profilin complex. CD spectra revealed an increase of up to 3.3-fold in the molar ellpticity at 222 nm for profilin as it binds PIP2, as well as changes in the Cotton effect between 250 and 310 nm. These results are consistent with a possible increase in the alpha-helix content of profilin triggered by the binding of PIP2. 相似文献
293.
Zinnia grandiflora afforded a new elemanolide with a δ-lactone ring. 相似文献
294.
Philippe Richard Franoise Moos Govindan Dayanithi Laurent Gouznes Nancy Sabatier 《Biology of the cell / under the auspices of the European Cell Biology Organization》1997,89(9):555-560
Electrophysiological recordings in lactating rats show that oxytocin (OT) and vasopressin (AVP) neurons exhibit specific patterns of activities in relation to peripheral stimuli: periodic bursting firing for OT neurons during suckling, phasic firing for AVP neurons during hyperosmolarity (systemic injection of hypertonic saline). These activities are autocontrolled by OT and AVP released somato-dentritically within the hypothalamic magnocellular nuclei. In vivo, OT enhances the amplitude and frequency of bursts, an effect accompanied with an increase in basal firing rate. However, the characteristics of firing change as facilitation proceeds: the spike patterns become very irregular with clusters of spikes spaced by long silences; the firing rate is highly variable and clearly oscillates before facilitated bursts. This unstable behaviour dramatically decreases during intense tonic activation which temporarily interrupts bursting, and could therefore be a prerequisite for bursting. In vivo, the effects of AVP depend on the initial firing pattern of AVP neurons: AVP excites weakly active neurons (increasing duration of active periods and decreasing silences), inhibits highly active neurons, and does not affect neurons with intermediate phasic activity. AVP brings the entire population of AVP neurons to discharge with a medium phasic activity characterised by periods of firing and silence lasting 20–40 s, a pattern shown to optimise the release of AVP from the neurohypophysis. Each of the peptides (OT or AVP) induces an increase in intracellular Ca2+ concentration, specifically in the neurons containing either OT or AVP respectively. OT evokes the release of Ca2+ from IP3-sensitive intracellular stores. AVP induces an influx of Ca2+ through voltage-dependent Ca2+ channels of T-, L- and N-types. We postulate that the facilitatory autocontrol of OT and AVP neurons could be mediated by Ca2+ known to play a key role in the control of the patterns of phasic neurons. 相似文献
295.
M. V. Govindan 《Experimental cell research》1980,127(2):293-297
Antibodies to the two dexamethasone-binding proteins from rat liver cytosol have been elicited in rabbits. These antibodies precipitate the dexamethasone binding activities from rat liver cytosol as weil as cytosol from Hepatoma Tissue Culture (HTC) cells. Antibodies to the 45 000 D protein have been used for demonstration of the intracellular dynamics of the glucocorticoid receptor complex by immunofluorescence microscopy, comparing HTC cells treated with dexamethasone at 4 and 37 °C. 相似文献
296.
297.
Ashok Kumar Singhal Ram Prakash Sharma Jogendra Nath Baruah Serengolam V. Govindan Werner Herz 《Phytochemistry》1982,21(4):949-951
Roots of Millettia pachycarpa furnished retenone, cis-12a-hydroxyrotenone, rot-2′-enonic acid and cis-12a-hydroxyrot-2′-enonic acid. 相似文献