全文获取类型
收费全文 | 5972篇 |
免费 | 840篇 |
国内免费 | 3篇 |
出版年
2021年 | 78篇 |
2019年 | 55篇 |
2016年 | 84篇 |
2015年 | 128篇 |
2014年 | 165篇 |
2013年 | 217篇 |
2012年 | 274篇 |
2011年 | 271篇 |
2010年 | 153篇 |
2009年 | 155篇 |
2008年 | 226篇 |
2007年 | 203篇 |
2006年 | 216篇 |
2005年 | 197篇 |
2004年 | 215篇 |
2003年 | 163篇 |
2002年 | 195篇 |
2001年 | 176篇 |
2000年 | 190篇 |
1999年 | 174篇 |
1998年 | 104篇 |
1997年 | 57篇 |
1996年 | 73篇 |
1995年 | 87篇 |
1994年 | 77篇 |
1993年 | 75篇 |
1992年 | 144篇 |
1991年 | 148篇 |
1990年 | 126篇 |
1989年 | 142篇 |
1988年 | 135篇 |
1987年 | 121篇 |
1986年 | 107篇 |
1985年 | 95篇 |
1984年 | 88篇 |
1983年 | 89篇 |
1982年 | 60篇 |
1981年 | 69篇 |
1980年 | 56篇 |
1979年 | 99篇 |
1978年 | 69篇 |
1977年 | 78篇 |
1976年 | 68篇 |
1975年 | 77篇 |
1974年 | 95篇 |
1973年 | 74篇 |
1972年 | 78篇 |
1971年 | 67篇 |
1970年 | 66篇 |
1968年 | 54篇 |
排序方式: 共有6815条查询结果,搜索用时 15 毫秒
141.
Warren O. Kessler Ruben F. Gittes Sheldon R. Hurwitz Joseph P. Green 《The Western journal of medicine》1974,121(2):91-93
Gallium-67 (67Ga) citrate was administered intravenously (50 microcuries per kg of body weight) to patients in whom acute and chronic urinary tract infections were suspected. Scanning was done, using both the Anger-type scintillation camera and the rectilinear scanner, 24 to 78 hours after injection of the isotope.The preliminary results imply that 67Ga renal uptake is present in patients with pyelonephritis whether overt or silent, as well as in patients with uretero-sigmoidostomies. However, 67Ga renal uptake is not present in patients with radiographic evidence of chronic pyelonephritis without active infection and in patients without renal disease. 相似文献
142.
143.
144.
Conformational basis of energy transduction in mitochondria 总被引:1,自引:0,他引:1
145.
The isolation of cod muscle tropomyosin by heat treatment 总被引:1,自引:0,他引:1
146.
147.
Origin of the Thymidine Kinase Induced by Polyoma Virus in Productively Infected Cells 总被引:13,自引:4,他引:9 下载免费PDF全文
Cells of the 3T3 mouse line efficiently supported the multiplication of polyoma virus, and the infectious process was accompanied by a marked increase in thymidine kinase (TK) activity. Two lines of 5-bromodeoxyuridine-resistant 3T3 cells have been isolated. As expected, these cells incorporated practically no exogenous thymidine into their deoxyribonucleic acid (DNA) and contained negligible TK activity. Like the parental 3T3 cells, TK(-) lines were susceptible to productive infection by polyoma virus, but infection did not lead to an increase in TK activity. Since kinase activity did appear after infection with another virus (vaccinia) known to contain the gene(s) for that enzyme, it is concluded that TK is not one of the gene products of polyoma virus. As induction of cellular DNA synthesis by polyoma virus occurs normally when the TK(-) cells are infected in the stationary phase, TK cannot play a role in the determination of this phenomenon. 相似文献
148.
149.
150.