全文获取类型
收费全文 | 6477篇 |
免费 | 453篇 |
国内免费 | 2篇 |
出版年
2021年 | 50篇 |
2019年 | 61篇 |
2018年 | 78篇 |
2017年 | 75篇 |
2016年 | 107篇 |
2015年 | 125篇 |
2014年 | 156篇 |
2013年 | 344篇 |
2012年 | 335篇 |
2011年 | 255篇 |
2010年 | 184篇 |
2009年 | 159篇 |
2008年 | 300篇 |
2007年 | 316篇 |
2006年 | 310篇 |
2005年 | 257篇 |
2004年 | 315篇 |
2003年 | 312篇 |
2002年 | 321篇 |
2001年 | 245篇 |
2000年 | 222篇 |
1999年 | 189篇 |
1998年 | 82篇 |
1997年 | 68篇 |
1996年 | 52篇 |
1995年 | 47篇 |
1994年 | 60篇 |
1993年 | 60篇 |
1992年 | 145篇 |
1991年 | 115篇 |
1990年 | 139篇 |
1989年 | 140篇 |
1988年 | 115篇 |
1987年 | 110篇 |
1986年 | 103篇 |
1985年 | 87篇 |
1984年 | 80篇 |
1983年 | 63篇 |
1982年 | 52篇 |
1981年 | 46篇 |
1980年 | 38篇 |
1979年 | 72篇 |
1978年 | 54篇 |
1977年 | 47篇 |
1976年 | 37篇 |
1975年 | 41篇 |
1974年 | 42篇 |
1973年 | 39篇 |
1972年 | 47篇 |
1970年 | 33篇 |
排序方式: 共有6932条查询结果,搜索用时 46 毫秒
1.
2.
3.
M Mizuno K Yashiro Y Kameyama S Hayashi Y Sakashita Y Yokota 《Comparative biochemistry and physiology. B, Comparative biochemistry》1990,96(1):171-176
1. Chronic administration of isoproterenol caused similar alterations of membrane lipid profile in at least two rat parotid subcellular fractions, secretory granular and microsomal. 2. Typical changes in phospholipid classes and fatty-acyl chain groups were an increase of phosphatidylcholine and a decrease of sphingomyelin, and an increase of octadecadienoyl chain and a decrease of eicosatetraenoyl chain, respectively. 3. Electron spin resonance study showed that the isoproterenol-treatment also affected a membrane physical property, which may be through these compositional changes in membrane constituents. 相似文献
4.
The presence of a human hepatocyte growth factor (hHGF)-like DNA-synthesis promoter in platelet-poor serum of mice with liver injury was examined. Activity of the serum for stimulating DNA synthesis in cultured rat hepatocytes was low in untreated or vehicle-treated mice, but markedly increased 24 h after carbon tetrachloride administration and then dropped to normal levels prior to the peak of liver DNA synthesis. The effect of the serum was additive with the maximal effects of mouse and human epidermal growth factors, but not with that of hHGF. The growth-stimulating factor in the mouse serum, like hHGF, had affinity for heparin and was heat-labile. These results indicate that the level of a serum hHGF-like hepatocyte growth factor increased in mice treated with carbon tetrachloride prior to liver regeneration. 相似文献
5.
6.
7.
Ruofan Wang Camille R. Simoneau Jessie Kulsuptrakul Mehdi Bouhaddou Katherine A. Travisano Jennifer M. Hayashi Jared Carlson-Stevermer James R. Zengel Christopher M. Richards Parinaz Fozouni Jennifer Oki Lauren Rodriguez Bastian Joehnk Keith Walcott Kevin Holden Anita Sil Jan E. Carette Nevan J. Krogan Andreas S. Puschnik 《Cell》2021,184(1):106-119.e14
8.
Changes in Targeting Efficiencies of Proteins to Plant Microbodies Caused by Amino Acid Substitutions in the Carboxy-terminal Tripeptide 总被引:7,自引:0,他引:7
Hayashi Makoto; Aoki Masahiro; Kondo Maki; Nishimura Mikio 《Plant & cell physiology》1997,38(6):759-768
It has been demonstrated that the carboxyl terminus of microbodyenzymes functions as a targeting signal to microbodies in higherplants. We have examined an ability of 24 carboxy-terminal aminoacid sequences to facilitate the transport of a cytosolic passengerprotein, ß-glucuroni-dase, into microbodies in greencotyledonary cells of trans-genic Arabidopsis. Immunoelectronmicroscopic analysis revealed that carboxy-terminal tripeptidesequences of the form [C/A/S/P]-[K/R]-[I/L/M] function as amicrobody-targeting signal, although tripeptides with prolineat the first amino acid position and isoleucine at the carboxylterminus show weak targeting efficiencies. All known micro-bodyenzymes that are synthesized in a form similar in size to themature molecule, except catalase, contain one of these tripeptidesequences at their carboxyl terminus. (Received April 14, 1997; Accepted April 8, 1997) 相似文献
9.
Hidenori Suzuki Naomasa Yamamoto Kenjiro Tanoue Hiroh Yamazaki 《The Histochemical journal》1987,19(3):125-136
Summary Using a monoclonal antibody (TM60) against glycoprotein (GP) Ib, we determined immunocytochemically how GPIb is distributed on the platelet surface. When glutaraldehyde-fixed platelets were incubated with TM60, a uniform distribution of ferritin particles which represent the localization of GPIb was observed on the surface membrane of platelets. The particles were distributed at intervals of about 100 nm. The number of ferritin particles on the surface of one side were 2070–4150 (2940 ± 790; mean ±s.d.,n = 10) under the scanning electron microscope. The distribution of ferritin particles was somewhat disarranged on the surface of unfixed platelets incubated with TM60 compared to that in the fixed platelets. Cluster-like structures of ferritin particles were observed in several places. When platelets were activated with ristocetin or thrombin, the distribution of ferritin particles was disturbed and cluster formation was observed in several places on the surface. These findings suggest that GPIb is uniformly distributed on the surface of platelets in the resting state, and that cluster formation occurs during activation of platelets. 相似文献
10.