全文获取类型
收费全文 | 5586篇 |
免费 | 585篇 |
国内免费 | 9篇 |
出版年
2022年 | 56篇 |
2021年 | 86篇 |
2020年 | 43篇 |
2019年 | 53篇 |
2018年 | 60篇 |
2017年 | 62篇 |
2016年 | 99篇 |
2015年 | 198篇 |
2014年 | 248篇 |
2013年 | 242篇 |
2012年 | 335篇 |
2011年 | 343篇 |
2010年 | 203篇 |
2009年 | 163篇 |
2008年 | 253篇 |
2007年 | 235篇 |
2006年 | 248篇 |
2005年 | 212篇 |
2004年 | 232篇 |
2003年 | 215篇 |
2002年 | 210篇 |
2001年 | 154篇 |
2000年 | 168篇 |
1999年 | 132篇 |
1998年 | 75篇 |
1997年 | 49篇 |
1996年 | 55篇 |
1995年 | 49篇 |
1994年 | 56篇 |
1992年 | 99篇 |
1991年 | 101篇 |
1990年 | 81篇 |
1989年 | 81篇 |
1988年 | 74篇 |
1987年 | 103篇 |
1986年 | 72篇 |
1985年 | 93篇 |
1984年 | 77篇 |
1983年 | 58篇 |
1982年 | 51篇 |
1981年 | 40篇 |
1980年 | 41篇 |
1979年 | 71篇 |
1978年 | 41篇 |
1977年 | 57篇 |
1976年 | 36篇 |
1975年 | 41篇 |
1974年 | 50篇 |
1973年 | 43篇 |
1967年 | 33篇 |
排序方式: 共有6180条查询结果,搜索用时 31 毫秒
1.
Four myeloid cell lines (M1, WEHI-3B D+, FDC-P1, and 32D) were screened for the presence of J11d antigen. One of these cell lines, the myeloid leukemia M1, was found to express a high level of J11d antigen on the cell surface. Recombinant mouse leukemic inhibitory factor (rm-LIF), recombinant human LIF (rh-LIF), and steroids (hydrocortisone and dexamethasone) could induce M1 cells to undergo monocytic differentiation. The level of J11d antigen was greatly reduced after treatment of the cells with LIF or steroids. Western blotting revealed that the apparent molecular weight of the J11d antigen on M1 cells was 45-48 kDa. Furthermore, the level of J11d mRNA was also reduced during LIF-induced differentiation of M1 cells. 相似文献
2.
3.
4.
F Stephen Perry 《BMJ (Clinical research ed.)》1998,317(7156):481
5.
Amy Chapman Gonzalo Gonzales Wayne R. Burrowes Paul Assanah Bernadette Iannone Michael K. Leung George B. Stefano 《Cellular and molecular neurobiology》1984,4(2):143-155
In Mytilus and Leucophaea the high-affinity binding site density is significantly lower in old animals than in young animals, whereas the low-affinity site density remains unchanged. In Mytilus the estimated met-enkephalin and met-enkephalin-Arg6-Phe7 levels are significantly higher in old than in young animals. In Leucophaea only the met-enkephalin level can be determined, and it is also higher in old animals. The decrease in the high-affinity binding site density and the corresponding increase in endogenous enkephalin levels suggest the existence of an opioid compensatory mechanism associated with the aging process. In Mytilus there is a demonstrated decrease with age in intraganglionic dopamine levels in response to applied opiates. In addition, the inhibition of dopamine-stimulated adenylate cyclase activity by opiates also decreases in older animals. In Leucophaea the sex difference in opioid binding densities diminishes with age. 相似文献
6.
7.
G A Dunaway G L Leung J R Thrasher M D Cooper 《The Journal of biological chemistry》1978,253(20):7460-7463
Earlier work demonstrated that the activity of liver phosphofructokinase (PFK-L2) and immunoreactive PFK-L2 were decreased in diabetic rats and increased to normal or super-normal amounts following insulin treatment (Dunaway, G.A., and Weber, G., (1974) Arch. Biochem. Biophys. 162, 629-637). This report indicates that the decrease in levels of PFK-L2 in diabetic rats is a result of an accelerated degradation rate while the synthetic rate remains nearly normal. Following insulin treatment, the rate of PFK-L2 synthesis is enhanced 2-fold, whereas the rate of degradation appears to be greatly diminished. An inverse relationship is shown to exist between the PFK-L2 levels and the rates of PFK-L2 degradation, suggesting that the levels of PFK-L2 are primarily regulated by degradation rate. In addition, the levels of the PFK-L2 peptide stabilizing factor are inversely proportional to rates of PFK-L2 degradation. These results indicate that insulin mediates the rate of degradation of PFK-L2 by controlling the level of the peptide stabilizing factor. 相似文献
8.
Nataly Mancette Rijensky Netta R. Blondheim Shraga Eilon Barnea Nir Peled Eli Rosenbaum Aron Popovtzer Solomon M. Stemmer Alejandro Livoff Mark Shlapobersky Neta Moskovits Dafna Perry Eitan Rubin Itzhak Haviv Arie Admon 《Molecular & cellular proteomics : MCP》2020,19(8):1360-1374
- Download : Download high-res image (147KB)
- Download : Download full-size image
- •Sufficient tumor tissues are often unavailable large HLA peptidome discovery.
- •Using patient derived xenograft (PDX) tumors can overcome this limitation.
- •The large PDX HLA peptidomes expand significantly those of the original biopsies.
- •The HLA peptidomes of the PDX tumors included many tumor antigens.
9.
10.
Q Yuan W M Jiang D Hollander E Leung J D Watson G W Krissansen 《Biochemical and biophysical research communications》1991,176(3):1443-1449
A cDNA clone encoding the N-terminal sequence of the murine integrin beta 7 subunit, a novel member of the leukocyte cell adhesion molecule subset (Leu-CAM), has been isolated. An N-terminal region of 13 contiguous amino acids deduced from the cDNA shows complete identity with the N-terminus of the 120 kDa subunit of the M290 antigen, a surface molecule found highly expressed on mouse intestinal intraepithelial lymphocytes (IEL). This unexpected result focuses two previously unconnected areas of research and suggests that integrins may have a special role to play in the defence of the gut mucosa. 相似文献