全文获取类型
收费全文 | 1721篇 |
免费 | 190篇 |
专业分类
1911篇 |
出版年
2023年 | 8篇 |
2022年 | 29篇 |
2021年 | 47篇 |
2020年 | 13篇 |
2019年 | 26篇 |
2018年 | 36篇 |
2017年 | 20篇 |
2016年 | 51篇 |
2015年 | 80篇 |
2014年 | 70篇 |
2013年 | 89篇 |
2012年 | 117篇 |
2011年 | 103篇 |
2010年 | 76篇 |
2009年 | 68篇 |
2008年 | 100篇 |
2007年 | 95篇 |
2006年 | 93篇 |
2005年 | 74篇 |
2004年 | 82篇 |
2003年 | 78篇 |
2002年 | 76篇 |
2001年 | 20篇 |
2000年 | 18篇 |
1999年 | 26篇 |
1998年 | 23篇 |
1997年 | 18篇 |
1996年 | 17篇 |
1995年 | 14篇 |
1994年 | 9篇 |
1993年 | 17篇 |
1992年 | 11篇 |
1991年 | 14篇 |
1990年 | 10篇 |
1989年 | 15篇 |
1988年 | 12篇 |
1987年 | 16篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 20篇 |
1981年 | 11篇 |
1979年 | 13篇 |
1978年 | 12篇 |
1976年 | 13篇 |
1975年 | 10篇 |
1973年 | 8篇 |
1972年 | 10篇 |
1970年 | 10篇 |
排序方式: 共有1911条查询结果,搜索用时 8 毫秒
41.
Blood counts were performed on 100 male and 100 female staff to establish normal ranges for our hospital. Neutrophil counts were found to be on average 0.66 times 10-9/1 (660/mm-3) higher in women than in men. Statistically this difference was highly significant and was not due to the fact that many of the women were taking oral contraceptives. The neutrophil counts of the men and women were also on average 0.50 times 10-9/1 (500/mm-3) greater in the afternoon than in the morning. A correlation was observed between the neutrpphil and the monocyte counts. 相似文献
42.
43.
44.
Christine A. Bricault Karina Yusim Michael S. Seaman Hyejin Yoon James Theiler Elena E. Giorgi Kshitij Wagh Maxwell Theiler Peter Hraber Jennifer P. Macke Edward F. Kreider Gerald H. Learn Beatrice H. Hahn Johannes F. Scheid James M. Kovacs Jennifer L. Shields Christy L. Lavine Fadi Ghantous Bette Korber 《Cell host & microbe》2019,25(1):59-72.e8
45.
46.
In Saccharomyces cerevisiae the nicotinic acid moiety of NAD+ can be synthesized from tryptophan using the kynurenine pathway or incorporated directly using nicotinate phosphoribosyl transferase (NPT1). We have identified the genes that encode the enzymes of the kynurenine pathway and for BNA5 (YLR231c) and BNA6 (YFR047c) confirmed that they encode kynureninase and quinolinate phosphoribosyl transferase respectively. We show that deletion of genes encoding kynurenine pathway enzymes are co-lethal with the Deltanpt1, demonstrating that no other pathway for the synthesis of nicotinic acid exists in S. cerevisiae. Also, we show that under anaerobic conditions S. cerevisiae is a nicotinic acid auxotroph. 相似文献
47.
A biowaste kill system was implemented to treat biological waste generated from a clinical manufacturing and R&D antibody facility. To confirm that design parameters of this continuous decontamination system are sufficient to inactivate mammalian cell culture waste, bench-scale experiments were conducted. The biowaste kill system heat inactivates mammalian cell cultures before they are piped to a neutralization tank and subsequently released to the sewage system. Heat inactivation of cells is accomplished by exposing cells to 80 degrees C for 1 min. Small-scale heat inactivation studies were performed on CHO, 293-HEK, and hybridoma cells. Cells at 1 x 10(6) cells/mL or 1 x 10(7) cells/mL were exposed to 37, 60, 70, or 80 degrees C for 0, 30, 60, and 120 s. Viability based on trypan blue exclusion method and ability to proliferate was assessed after exposure to heat. Data suggest that exposure of cells to 80 degrees C for 60 s is sufficient to inactivate these cultures before they are released to the sewage system. 相似文献
48.
49.
50.
The trabecular meshwork (TM), a specialized eye tissue, is a major site for regulation of the aqueous humor outflow. Malfunctioning of this tissue is believed to be responsible for development of glaucoma, a blinding disease. Myocilin is a gene linked to the most common form of glaucoma. The protein product has been localized to both intra and extracellular sites, but its function still remains unclear. This study was to determine whether extracellular myocilin presented in the matrix affects adhesion, morphology, and migratory and phagocytic activities of human TM cells in culture. Cell adhesion assays indicated that TM cells, while adhering readily on fibronectin, failed to attach on recombinant myocilin purified from bacterial cultures. Adhesion on fibronectin was also compromised by myocilin in a dose dependent manner. Myocilin in addition triggered TM cells to assume a stellate appearance with broad cell bodies and microspikes. Loss of actin stress fibers and focal adhesions was observed. TM cell migration on fibronectin/myocilin to scratched wounds was reduced compared to fibronectin controls. Myocilin, however, had little impact on phagocytic activities of TM cells. Cell attachment on fibronectin and migration of corneal fibroblasts, a control cell type, were not altered by myocilin. These results demonstrate that extracellular myocilin elicits anti-adhesive and counter-migratory effects on TM cells. Myocilin in the matrix of tissues could be exerting a similar influence on TM cells in vivo, impacting the flexibility and resilience required for maintenance of the normal aqueous outflow. 相似文献