全文获取类型
收费全文 | 11029篇 |
免费 | 1134篇 |
国内免费 | 1篇 |
出版年
2022年 | 96篇 |
2021年 | 216篇 |
2020年 | 95篇 |
2019年 | 141篇 |
2018年 | 176篇 |
2017年 | 148篇 |
2016年 | 279篇 |
2015年 | 434篇 |
2014年 | 515篇 |
2013年 | 631篇 |
2012年 | 808篇 |
2011年 | 799篇 |
2010年 | 545篇 |
2009年 | 522篇 |
2008年 | 665篇 |
2007年 | 674篇 |
2006年 | 708篇 |
2005年 | 587篇 |
2004年 | 547篇 |
2003年 | 524篇 |
2002年 | 473篇 |
2001年 | 192篇 |
2000年 | 144篇 |
1999年 | 128篇 |
1998年 | 122篇 |
1997年 | 86篇 |
1996年 | 92篇 |
1995年 | 76篇 |
1994年 | 76篇 |
1993年 | 79篇 |
1992年 | 100篇 |
1991年 | 102篇 |
1990年 | 95篇 |
1989年 | 113篇 |
1988年 | 93篇 |
1987年 | 83篇 |
1986年 | 61篇 |
1985年 | 69篇 |
1984年 | 57篇 |
1983年 | 58篇 |
1981年 | 45篇 |
1979年 | 52篇 |
1978年 | 54篇 |
1977年 | 46篇 |
1976年 | 40篇 |
1975年 | 47篇 |
1974年 | 45篇 |
1973年 | 44篇 |
1972年 | 40篇 |
1970年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
105.
106.
107.
108.
109.
Cultured renal collecting duct cells from neonatal rabbit kidney were used to examine the influence of aldosterone on enzymatic activity of citrate synthase during increase in Na+ transport. Control epithelia showed citrate synthase activity of 71 +/- 3 mU/mg protein (n = 28), while after aldosterone treatment citrate synthase activity was significantly increased to 79 +/- 6 mU/mg at 1 h (n = 5), to 88 +/- 6 mU/mg at 2 h (n = 6) and to 93 +/- 8 mU/mg protein at 3 h (n = 5). Citrate synthase activity subsequently decreased to basal values. Spironolactone fully blocked the aldosterone-induced increase in citrate synthase activity. The time course of enzyme stimulation after aldosterone administration indicates that the hormone activates citrate synthase during the physiological early response phase. 相似文献
110.
We report a novel technique that combines high-resolution scanning electron microscopy (SEM) of intracellular structures with backscattered electron imaging (BEI) of colloidal gold-labeled intracellular ligands. Murine dorsal root ganglia were immersion-fixed, freeze-cleaved, labeled with gold complexes, and critical point-dried. Specimens were carbon-coated and viewed by BEI. They were then minimally sputter-coated with gold and previously identified cells relocated by secondary electron imaging (SEI). This permitted increased resolution of intracellular detail while gold particles remained detectable by BEI. Incubation with RNAse-gold and DNAse-gold complexes resulted in specific labeling of cytoplasm and nucleus, respectively. Immunolabeling of neurofilament (NF) and small nuclear ribonucleoproteins (snRNP) resulted in selective labeling of intracellular antigens. Nonspecific binding was abolished by use of 1% skin milk. Specifically, incubation with monoclonal anti-NF68 resulted in labeling of cytoplasm in 66% of neurons, notably of the large cells known to contain large amounts of NF. Satellite cells, which lack NF, showed low levels of background label. Human autoimmune anti-Sm serum recognizes snRNP particles, with the exception of the nucleolar U3 snRNP. Labeling with this serum resulted in specific labeling of 92% of nuclei, with only background labeling over nucleoli and cytoplasm. The results show that it is feasible to employ high-resolution SEM in conjunction with colloidal gold labeling to localize intracellular ligands in situ. 相似文献