全文获取类型
收费全文 | 119283篇 |
免费 | 8167篇 |
国内免费 | 214篇 |
专业分类
127664篇 |
出版年
2021年 | 1252篇 |
2020年 | 1115篇 |
2019年 | 1082篇 |
2018年 | 2649篇 |
2017年 | 2375篇 |
2016年 | 3187篇 |
2015年 | 4087篇 |
2014年 | 4356篇 |
2013年 | 5650篇 |
2012年 | 6571篇 |
2011年 | 5929篇 |
2010年 | 3909篇 |
2009年 | 3107篇 |
2008年 | 4890篇 |
2007年 | 4670篇 |
2006年 | 4650篇 |
2005年 | 3903篇 |
2004年 | 3874篇 |
2003年 | 3498篇 |
2002年 | 3258篇 |
2001年 | 4641篇 |
2000年 | 4215篇 |
1999年 | 3148篇 |
1998年 | 1194篇 |
1997年 | 947篇 |
1996年 | 951篇 |
1995年 | 830篇 |
1992年 | 2130篇 |
1991年 | 1941篇 |
1990年 | 1848篇 |
1989年 | 1865篇 |
1988年 | 1609篇 |
1987年 | 1625篇 |
1986年 | 1431篇 |
1985年 | 1473篇 |
1984年 | 1132篇 |
1983年 | 1011篇 |
1979年 | 1232篇 |
1978年 | 885篇 |
1977年 | 854篇 |
1975年 | 1016篇 |
1974年 | 1139篇 |
1973年 | 1101篇 |
1972年 | 1067篇 |
1971年 | 994篇 |
1970年 | 1012篇 |
1969年 | 1080篇 |
1968年 | 944篇 |
1967年 | 811篇 |
1966年 | 827篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
H. Štorchová 《Biologia Plantarum》1994,36(3):358-358
72.
73.
74.
Effect of pharmacological agents on the activity of the circular and longitudinal smooth muscle layers of human fallopian tube ampullar segments 总被引:1,自引:0,他引:1
The in vitro determination of the effects of some pharmacological agents on the outer diameter and axial tension of human Fallopian tube ampullar segments showed that some drugs may act on the circular and longitudinal smooth muscle layers relatively separately. PGF2 alpha elicited an excitatory response in both muscle layers while norepinephrine and isoproterenol decreased the activity. Oxytocin and indomethacin had relatively limited effects on the spontaneous motility of the ampullar segments. The calcium antagonist verapamil inhibited the spontaneous periodic activity. 相似文献
75.
L V Gankovskaia A Z Tskhovrebova N A Gvozdeva L V Koval'chuk A N Cheredeev 《Biulleten' eksperimental'no? biologii i meditsiny》1986,102(8):210-213
Fractions containing macrophage migration inhibition factor (MIF) and leucocyte migration inhibition factor (LIF) were obtained using Sephadex G-200 filtration from supernatant fluids of human lymphocyte cultures stimulated by PHA. The fractions were tested for the ability to affect migration and phagocytic activity of target cells. Peripheral blood leucocyte migration capacity was inhibited by the fraction with the molecular mass of 60,000-70,000 D (LIF), while migration activity of mouse peritoneal exudate cells was suppressed by the fraction with the molecular mass of 20,000-30,000 D (MIF). MIF- and LIF-containing fractions increased almost three-fold Fc-receptor-mediated phagocytic activity of neutrophils. 相似文献
76.
V T Kondakov A B Okulov M A Filippkin R Z Tandilava I U Artamonov O A Voronenko A N Sazonov 《Vestnik rentgenologii i radiologii》1991,(4):31-35
The paper is concerned with analysis of the results of intraoperative phlebotesticulography, performed in 50 patients with varicocele of degree I-II during Ivanissevich's operation. The effect of surgical intervention was shown to depend upon the quality of ligation of the testicular vein, some parts of which are anastomosed between themselves. The localization of this anastomosis is revealed by means of intraoperative phlebotesticulography, which permits increasing the results of surgical treatment and predicting a course of a postoperative period. 相似文献
77.
78.
A strain of 1,507 typised donors enables 15.97 average donors to be selected for a thrombocyte transfusion in one of 75 patients selected at random with HLA antibodies being previously determined (1 to 66 donors per patient). HLA compatible donors were found for 72 patients (97.33 per cent). More than 5 HLA compatible donors could be found for 58 patients. The high number of compatible donors is based on the fact that among 1,507 donors there were 156 HLA homozygotes and 556 donors with 3 HLA-A or B-antigens respectively. Compatibility in the ABO-system was not taken into account. 相似文献
79.
Luís M. S. Loura Fábio Fernandes Manuel Prieto 《European biophysics journal : EBJ》2010,39(4):589-607
Lateral membrane heterogeneity, in the form of lipid rafts and microdomains, is currently implicated in cell processes including signal transduction, endocytosis, and cholesterol trafficking. Various biophysical techniques have been used to detect and characterize lateral membrane domains. Among these, Förster resonance energy transfer (FRET) has the crucial advantage of being sensitive to domain sizes smaller than 50-100 nm, below the resolution of optical microscopy but, apparently, similar to those of rafts in cell membranes. In the last decade, several formalisms for the analysis of FRET in heterogeneous membrane systems have been derived and applied to the study of microdomains. They are critically described and illustrated here. 相似文献
80.
W J Theuvenet T Nolthenius-Puylaert Z L Giedrojc Juraha J M Borghouts R van Twisk 《Plastic and reconstructive surgery》1984,74(4):539-543
Idiopathic calcinosis of the scrotum is a rare disease that may cause massive deformation of the scrotal wall. The first patient we present was also known to have neurofibromatosis. In the second patient we describe, nodules of idiopathic calcinosis of the scrotum were seen with walls that evidenced no epithelial lining, as well as calcification in epithelial cysts. At present, the only possible treatment is excision, and we excised the afflicted skin without problems in primary wound closure. 相似文献