全文获取类型
收费全文 | 925篇 |
免费 | 69篇 |
专业分类
994篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 14篇 |
2019年 | 14篇 |
2018年 | 25篇 |
2017年 | 16篇 |
2016年 | 23篇 |
2015年 | 42篇 |
2014年 | 39篇 |
2013年 | 62篇 |
2012年 | 87篇 |
2011年 | 61篇 |
2010年 | 41篇 |
2009年 | 43篇 |
2008年 | 50篇 |
2007年 | 45篇 |
2006年 | 35篇 |
2005年 | 33篇 |
2004年 | 31篇 |
2003年 | 38篇 |
2002年 | 40篇 |
2001年 | 15篇 |
2000年 | 22篇 |
1999年 | 21篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 4篇 |
1992年 | 17篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 15篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1969年 | 3篇 |
1966年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有994条查询结果,搜索用时 0 毫秒
991.
Variations in the spontaneous contractile activity during 6 hours following isolation of uterine horns from proestrus, metestrus and spayed rats, were explored. In estrus and metestrus preparations the contractions declined during 60 min and between 180--200 min a progressive spontaneous recovery (abolished by indomethacin) was observed up to 360 min. Uteri from proestrus and spayed animals exhibited a continuous depression without recovery during the whole experimental period. At 60 min, uterine horns from estrus animals (which showed a marked contractile decrement) released to the suspending medium significantly less prostaglandin E-like material than at 360 min, i.e. when contractions had almost completely recovered. No modification in the amount of prostaglandin F-like material was detected accompanying these spontaneous contractile variations. In the spayed group at 60 min of functioning (i.e. when the contractile impairment was significantly smaller than at a later time) the release of PGE was greater than at 360 min. These findings suggest a possible control of rat uterine contractions by PGE, rather than by PGF. 相似文献
992.
Sixty male Wistar rats were used for this experiment and assigned at random to the control group or to the stimulation method. Control rats show cerebral asymmetry with right bias at the frontal and occipital lobes. In the case of stimulated rats the differences from the occipital zone increase while those from the frontal lobe disappear. 相似文献
993.
M Chaud A M Franchi E T Gonzalez A L Gimeno M A Gimeno 《Prostaglandins, leukotrienes, and essential fatty acids》1990,41(3):207-213
The uptake of 14C-arachidonic acid (14C-AA) and 14C-dihomogamma-linolenic acid (14C-DGLA) into phospholipids (PLs) and neutral lipids (NLs) in uterine tissue obtained from ovariectomized controls (C) and from ovariectomized-diabetic rats (D) was studied. Uterine strips from D rats incorporate significantly less (P less than 0.05) 14C-AA into PLs than C rats. On the other hand the uptake of 14C-AA into NLs is significantly smaller (P less than 0.05) in uterine tissue from C than from D animals. The estrogenization of the C animals did not modify the incorporation of 14C-AA into PLs or NLs. On the contrary, uterine tissue obtained from D rats treated with 17-beta-estradiol incorporated significantly more labelled AA (P less than 0.05) into PLs and significantly less 14C-AA (P less than 0.05) into NLs than untreated D animals. The incorporation of 14C-DGLA into PLs shows similar pattern in uterine tissue obtained from C and D animals. Estrogenization increased significantly (P less than 0.01) in both cases, the incorporation into PLs. Regarding the incorporation of 14C-DGLA, it was clearly shown that DGLA is taken up significantly more (P less than 0.01) by NLs than by PLs, both in C and D rats. The estrogenization of C and D rats induces a significant decrease in the incorporation of 14C-DGLA into NLs in both experimental groups. The distribution of 14C-AA into the different subfractions of PLs is not uniform.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
994.
Julio Palomar Joan Francesc Guasch Miquel Regué Miquel Viñas 《FEMS microbiology letters》1990,69(3):255-258
No differences in the efficiency of transformation were observed from both plasmid and chromosomal DNA in Serratia marcescens 2170 and an extracellular nuclease defective isogenic strain. The efficiency of transformation was the same for Escherichia coli 5K and E. coli containing a recombinant plasmid conferring the ability to synthesize a S. marcescens nuclease. From these results we conclude that the extracellular nuclease of S. marcescens 2170 is not the main cause of the low efficiency of transformation observed in this bacterium. 相似文献