全文获取类型
收费全文 | 245篇 |
免费 | 24篇 |
出版年
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 12篇 |
2011年 | 16篇 |
2010年 | 10篇 |
2009年 | 6篇 |
2008年 | 12篇 |
2007年 | 13篇 |
2006年 | 12篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 4篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 10篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1947年 | 1篇 |
1942年 | 1篇 |
1940年 | 1篇 |
1919年 | 3篇 |
1889年 | 1篇 |
排序方式: 共有269条查询结果,搜索用时 15 毫秒
1.
Expression in Escherichia coli and characterization of the heat-stable inhibitor of the cAMP-dependent protein kinase 总被引:2,自引:0,他引:2
J Thomas S M Van Patten P Howard K H Day R D Mitchell T Sosnick J Trewhella D A Walsh R A Maurer 《The Journal of biological chemistry》1991,266(17):10906-10911
Pure heat-stable inhibitor of the cAMP-dependent protein kinase (PKI) has been isolated in high yield by using a bacterial expression vector constructed to synthesize the complete sequence of the rabbit muscle protein kinase inhibitor, plus an amino-terminal initiator methionine and glycine. Bacterially expressed PKI has an inhibitory activity identical to that of the protein isolated from rabbit skeletal muscle and, by gel filtration and gel electrophoresis, has the same physicochemical characteristics as the native physiological form of PKI. Fourier transformed infrared spectroscopy and CD establish that PKI has unusually large amounts of random coil and turn structures, with significantly smaller amounts of alpha-helix and beta structures. 相似文献
2.
3.
The reciprocal regulation of lipoprotein lipase activity and hormone-sensitive lipase activity in rat adipocytes 总被引:9,自引:0,他引:9
R L Patten 《The Journal of biological chemistry》1970,245(21):5577-5584
4.
Duncan T. Patten 《American journal of botany》1978,65(8):891-895
During years with good winter rainfall, ephemeral plants can contribute considerably to primary production in the upper Sonoran Desert. This study was designed to compare ephemeral community productivity and production efficiency within the different microhabitats created by trees, shrubs and open spaces in a Sonoran Desert ecosystem. Ephemerals were periodically harvested in the different habitats and dried for biomass and caloric determinations. The caloric data were compared to total solar input into the different microhabitats in order to determine production efficiencies of each stand. Productivity rates were also determined for the total community for the sample period, winters of 1972-74. Both productivity and production efficiency were highest under the shade of Cercidium. The highest production efficiency occurring in the shaded sites was 5.03% which approaches the theoretical maximum photosynthetic efficiency level. The production efficiency of the entire ephemeral community for the whole growing season was only 0.17% during an optimal year, demonstrating the influence of the environment in the interspaces on productivity and solar conversion in the desert. 相似文献
5.
6.
M G Clark G S Patten O H Filsell D Reppucci S W Leopardi 《Biochemical and biophysical research communications》1982,108(1):124-131
Epinephrine treatment of the perfused rat heart led to an increase in the rate of glucose uptake and lactate release as well as increases in the rate of beating and the activity ratio of phosphofructokinase. The dose of epinephrine required for half maximal increases in the rate of beating, and glucose uptake and the activity ratio of phosphofructokinase was approx.10?7M. Glucose uptake, lactate release and the activity ratio of phosphofructokinase were increased by the α-agonists methoxamine and phenylephrine, and the β agonist, isoproterenol. Propranolol and phenoxybenzamine each partially blocked the stimulatory effects of epinephrine on glucose uptake and lactate production. Phenoxybenzamine blocked the stimulatory effects of methoxamine but had no effect on those produced by isoproterenol which were blocked by propranolol. It is concluded that dual α and β adrenergic control of glycolysis occurs in cardiac muscle. It is proposed that the previously reported α-adrenergic control of phosphofructokinase plays a key role in the control of heart muscle glycolysis. 相似文献
7.
Visually guided action and interaction depends on the brain’s ability to (a) extract and (b) discriminate meaningful targets from complex retinal inputs. Binocular disparity is known to facilitate this process, and it is an open question how activity in different parts of the visual cortex relates to these fundamental visual abilities. Here we examined fMRI responses related to performance on two different tasks (signal-in-noise “coarse” and feature difference “fine” tasks) that have been widely used in previous work, and are believed to differentially target the visual processes of signal extraction and feature discrimination. We used multi-voxel pattern analysis to decode depth positions (near vs. far) from the fMRI activity evoked while participants were engaged in these tasks. To look for similarities between perceptual judgments and brain activity, we constructed ‘fMR-metric’ functions that described decoding performance as a function of signal magnitude. Thereafter we compared fMR-metric and psychometric functions, and report an association between judged depth and fMRI responses in the posterior parietal cortex during performance on both tasks. This highlights common stages of processing during perceptual performance on these tasks. 相似文献
8.
A clinically diagnosed case of progressive external ophthalmoplegia was biopsied and ultrastructurally evaluated. The disease was found to be characterized by numerous giant mitochondria. The intramitochondrial changes consisted of either swirls of cristae or of paracrystalline structures which were in apposition with the membranes of the cristae. The internal structure of the paracrystalline units consisted of parallel bands of material which were aligned in the same plane as the membranes of the related cristae. 相似文献
9.
van Patten N 《California and Western Medicine》1942,56(4):277-278
10.
Francisco úbeda David Haig Manus M. Patten 《Proceedings. Biological sciences / The Royal Society》2011,278(1707):855-862
Linkage disequilibrium (LD) is an association between genetic loci that is typically transient. Here, we identify a previously overlooked cause of stable LD that may be pervasive: sexual antagonism. This form of selection produces unequal allele frequencies in males and females each generation, which upon admixture at fertilization give rise to an excess of haplotypes that couple male-beneficial with male-beneficial and female-beneficial with female-beneficial alleles. Under sexual antagonism, LD is obtained for all recombination frequencies in the absence of epistasis. The extent of LD is highest at low recombination and for stronger selection. We provide a partition of the total LD into distinct components and compare our result for sexual antagonism with Li and Nei''s model of LD owing to population subdivision. Given the frequent observation of sexually antagonistic selection in natural populations and the number of traits that are often involved, these results suggest a major contribution of sexual antagonism to genomic structure. 相似文献