全文获取类型
收费全文 | 413篇 |
免费 | 59篇 |
出版年
2015年 | 7篇 |
2014年 | 5篇 |
2013年 | 6篇 |
2012年 | 15篇 |
2011年 | 13篇 |
2010年 | 9篇 |
2009年 | 8篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 7篇 |
2005年 | 8篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 15篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 13篇 |
1991年 | 21篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 11篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 12篇 |
1983年 | 13篇 |
1979年 | 10篇 |
1978年 | 9篇 |
1977年 | 8篇 |
1975年 | 11篇 |
1974年 | 9篇 |
1973年 | 10篇 |
1972年 | 15篇 |
1971年 | 7篇 |
1970年 | 8篇 |
1969年 | 14篇 |
1967年 | 9篇 |
1966年 | 6篇 |
1965年 | 5篇 |
1962年 | 3篇 |
1930年 | 3篇 |
1929年 | 3篇 |
1928年 | 4篇 |
排序方式: 共有472条查询结果,搜索用时 15 毫秒
111.
There is a higher incidence of restless legs syndrome (Ekbom''s syndrome) in patients after gastric surgery (11·3%) and with diabetes mellitus (17·0%) and uraemia (17·3%) than in patients who have been diagnosed as having a psychonoeurosis (4·0%) and in controls (2·0%). Three patients with malabsorption syndrome complained of restless legs, but these patients had abnormal neurological signs. The incidence after gastric surgery and in diabetes mellitus and uraemia remained high even when patients with any abnormal neurological signs were excluded. 相似文献
112.
113.
114.
115.
Washing bacteria by centrifugation through a water-immiscible layer of silicones 总被引:4,自引:3,他引:1
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hurwitz, Charles (Veterans Administration Hospital, Albany, N.Y.), Catherine B. Braun, and Richard A. Peabody. Washing bacteria by centrifugation through a water-immiscible layer of silicones. J. Bacteriol. 90:1692-1695. 1965.-A method is described which enables the separation of cells from aqueous suspension without altering the internal aqueous environment of the cells. The method consists of centrifuging the cells from the aqueous environment through a more dense, immiscible solvent consisting of a mixture of two silicones. A thin film of the aqueous environment equal to 7 x 10(-13) ml per cell remains with the bacteria during the separation procedure. The method by which this volume was determined is described. The procedure itself has no measurable effect on viability or permeability of the cells and permits recovery of about 90% of the cells from the aqueous environment. With this method, it has been found that the intracellular water volume of Escherichia coli ML 35 accessible to sucrose or inositol is 1.96 x 10(-12) ml +/- 6%, or 85% of the total volume of the cell determined by visual measurement. 相似文献
116.
117.
Chemnitz Galal W Pan M Giulian G Yuan W Li S Edwards JL Marino JP Kelman Z Hurwitz J 《The Journal of biological chemistry》2012,287(20):16220-16229
In the presence of dATP, glycerol, and Tris buffer, the DNA primase isolated from Thermococcus kodakaraensis catalyzed the formation of dAMP and two products that were identified as dAMP-glycerol and dAMP-Tris. These products were formed by the T. kodakaraensis p41 catalytic subunit alone and the T. kodakaraensis p41-p46 complex in the absence of a DNA template. They were not formed with preparations containing the catalytically inactive p41 subunit. Similar glycerol and Tris derivatives as well as dNMPs were also formed with dGTP, dCTP, or dTTP. The mechanism contributing to the formation of these products and its implications in the initiation reaction catalyzed by the T. kodakaraensis primase are discussed. 相似文献
118.
Chemnitz Galal W Pan M Kelman Z Hurwitz J 《The Journal of biological chemistry》2012,287(20):16209-16219
In most organisms, DNA replication is initiated by DNA primases, which synthesize primers that are elongated by DNA polymerases. In this study, we describe the isolation and biochemical characterization of the DNA primase complex and its subunits from the archaeon Thermococcus kodakaraensis. The T. kodakaraensis DNA primase complex is a heterodimer containing stoichiometric levels of the p41 and p46 subunits. The catalytic activity of the complex resides within the p41 subunit. We show that the complex supports both DNA and RNA synthesis, whereas the p41 subunit alone marginally produces RNA and synthesizes DNA chains that are longer than those formed by the complex. We report that the T. kodakaraensis primase complex preferentially interacts with dNTP rather than ribonucleoside triphosphates and initiates RNA as well as DNA chains de novo. The latter findings indicate that the archaeal primase complex, in contrast to the eukaryote homolog, can initiate DNA chain synthesis in the absence of ribonucleoside triphosphates. DNA primers formed by the archaeal complex can be elongated extensively by the T. kodakaraensis DNA polymerase (Pol) B, whereas DNA primers formed by the p41 catalytic subunit alone were not. Supplementation of reactions containing the p41 subunit with the p46 subunit leads to PolB-catalyzed DNA synthesis. We also established a rolling circle reaction using a primed 200-nucleotide circle as the substrate. In the presence of the T. kodakaraensis minichromosome maintenance (MCM) 3' → 5' DNA helicase, PolB, replication factor C, and proliferating cell nuclear antigen, long leading strands (>10 kb) are produced. Supplementation of such reactions with the DNA primase complex supported lagging strand formation as well. 相似文献
119.
120.
THE EXPRESSION OF APELIN AND ITS RECEPTOR APJ DURING DIFFERENT PHYSIOLOGICAL STAGES IN THE BOVINE OVARY 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《International journal of biological sciences》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Stefanie Schilffarth Bernadette Antoni Dieter Schams Heinrich HD Meyer Bajram Berisha 《International journal of biological sciences》2009,5(4):344-350
Recent studies implicate that apelin and its receptor APJ may have important role for the modulation of angiogenesis. The aim of this study was to further characterise the regulation of apelin/APJ system in bovine ovary. Experiment 1: corpora lutea (CL) were assigned to the following stages: days 1-2, 3-4, 5-7, 8-12, 13-16, >18 (after regression) of oestrous cycle and of gravidity (month <3, 3-5, 6-7 and >8). Experiment 2: Follicles during maturation were divided into granulosa cells (GC) and theca interna (TI) and were examined separately. Classification of follicles occurred by follicle size and oestradiol-17β (E2) concentration in the follicular fluid (FF) (<0.5 ng/ml, 0.5-5 ng/ml; 5-40 ng/ml; 40-180 ng/ml; >180 ng/ml). Real-time RT-PCR (qPCR) was applied to investigate mRNA expression of examined factors. In general, the expression level of apelin during the oestrous cycle was significantly higher compared to the one during pregnancy. Apelin mRNA levels were always high during the cycle with a tendency of decrease after CL regression. The APJ mRNA in the CL was significantly up regulated on days 5-7 and 8-12 followed by a decrease on days 13-16, and further on days >18. The expression of APJ does not show any significant regulation in the CL throughout pregnancy. The expression of apelin and APJ was not statistically regulated in GC, but was significantly up regulated in follicles with an E2 concentration of more than 5 ng/ml and showed an increase according to growth and maturation of follicles. In conclusion, our data suggest that apelin/APJ system is involved in the mechanism regulating angiogenesis during follicle maturation as well as during CL formation and function in the bovine ovary. 相似文献