全文获取类型
收费全文 | 2373篇 |
免费 | 251篇 |
专业分类
2624篇 |
出版年
2023年 | 12篇 |
2022年 | 28篇 |
2021年 | 46篇 |
2020年 | 40篇 |
2019年 | 46篇 |
2018年 | 47篇 |
2017年 | 51篇 |
2016年 | 66篇 |
2015年 | 106篇 |
2014年 | 110篇 |
2013年 | 133篇 |
2012年 | 198篇 |
2011年 | 153篇 |
2010年 | 94篇 |
2009年 | 87篇 |
2008年 | 142篇 |
2007年 | 132篇 |
2006年 | 108篇 |
2005年 | 123篇 |
2004年 | 123篇 |
2003年 | 120篇 |
2002年 | 113篇 |
2001年 | 35篇 |
2000年 | 11篇 |
1999年 | 27篇 |
1998年 | 31篇 |
1997年 | 30篇 |
1996年 | 14篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 29篇 |
1992年 | 21篇 |
1991年 | 16篇 |
1990年 | 20篇 |
1989年 | 23篇 |
1988年 | 12篇 |
1987年 | 12篇 |
1986年 | 11篇 |
1985年 | 15篇 |
1984年 | 18篇 |
1983年 | 15篇 |
1982年 | 9篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1977年 | 10篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1971年 | 12篇 |
1967年 | 6篇 |
排序方式: 共有2624条查询结果,搜索用时 0 毫秒
1.
2.
Sally P Wheatley 《Cell cycle (Georgetown, Tex.)》2015,14(2):261-268
Survivin is a multitasking protein that can inhibit cell death and that is essential for mitosis. Due to these prosurvival activities and the correlation of its expression with tumor resistance to conventional cancer treatments, survivin has received much attention as a potential oncotherapeutic target. Nevertheless, many questions regarding its exact role at the molecular level remain to be elucidated. In this study we ask whether the extreme C- and NH2 termini of survivin are required for it to carry out its cytoprotective and mitotic duties. When assayed for their ability to act as a cytoprotectant, both survivin1–120 and survivin11–142 were able to protect cells against TRAIL-mediated apoptosis, but when challenged with irradiation cells expressing survivin11–142 had no survival advantage. During mitosis, however, removing the NH2 terminal 10 amino acids (survivin11–142) had no apparent effect but truncating 22 amino acids from the C-terminus (survivin1–120) prevented survivin from transferring to the midzone microtubules during anaphase. Collectively the data herein presented suggest that the C-terminus is required for cell division, and that the NH2 terminus is dispensable for apoptosis and mitosis but required for protection from irradiation. 相似文献
3.
Elrashdy M. Redwan Vladimir N. Uversky Esmail M. El-Fakharany Hussein Al-Mehdar 《Comptes rendus biologies》2014,337(10):581-595
Lactoferrin (LF) is an 80-kDa globular glycoprotein with high affinity for metal ions, particularly for iron. This protein possesses many biological functions, including the binding and release of iron and serves as one of the important components of the innate immune system, where it acts as a potent inhibitor of several pathogens. LF has efficacious antibacterial and antiviral activities against a wide range of Gram-positive and Gram-negative bacteria and against both naked and enveloped DNA and RNA viruses. In its antiviral pursuit, LF acts predominantly at the acute phase of the viral infection or even at the intracellular stage, as in hepatitis C virus infection. LF inhibits the entry of viral particles into host cells, either by direct attachment to the viral particles or by blocking their cellular receptors. This wide range of activities may be attributed to the capacity of LF to bind iron and its ability to interfere with the cellular receptors of both hosts and pathogenic microbes. 相似文献
4.
5.
6.
Lela Jovanovich Sally Levin M. A. Q. Khan 《Journal of biochemical and molecular toxicology》1987,2(3):203-213
Treatment of rats with mirex (40 ppm in diet) caused hypoglycemia, liver enlargement, and inhibition of adrenal corticosteroid-synthesizing enzyme activity. At toxic dosages (20,000 ppm mirex in diet, which has a lethal toxicity-50 [LT-50] of ten days) poisoned female rats showed severe hypoglycemia, fatty liver, adrenal hyperplasia, hypophagia, lipid mobilization, and body weight (bw) loss. A 50 μg/kg intraperitoneal (IP) dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in male rats caused similar effects two days posttreatment. Hypoglycemia could be overcome by prednisone (which also inhibited adrenocorticoid-synthesizing enzyme activities) but not by streptozotocin treatment, indicating that hypoglycemia may be related to glucocorticoid deficiency resulting from inhibition of their synthesis and not by direct effects on pancreatic β-cells. Glucocorticoid deficiency could also cause increased release of adrenocorticoid hormone (ACTH), which may enhance fat mobilization caused by hypophagia. 相似文献
7.
8.
9.
Sally Engle Merry 《American anthropologist》2001,103(1):16-29
The new urban social order depends on a complex combination of systems of punishment, discipline, and security. Scholars drawing on Foucault's analysis of the art and rationality of governance, or govemmentality, have explored how urban social orders are increasingly based on the governance of space rather than on the discipline of offenders or the punishment of offenses. The new urban social order is characterized by privatized security systems and consumer-policed spaces such as malls. Gender violence interventions represent another deployment of spatial forms of govemmentality. Over the last two decades, punishment of batterers has been augmented by disciplinary systems that teach batterers new forms of masculinity and by security systems for women based on spatial separation. In the postmodern city, spatial govemmentality is integrally connected with punishment and discipline. These new forms of governance circulate globally along with neoliberal ideas of the diminished state, [gender violence, govemmentality, urban society, globalization, law] 相似文献
10.
Summary To assay the functional significance of the multiple but closely related - and -tubulin polypeptides (termed isotypes) that are expressed in mammalian cells, we have generated a number of sera that uniquely discriminate among these isotypes. These sera have been used to demonstrate that there is no subcellular sorting of either - or -tubulin isotypes among microtubules of diverse function, either in cells growing in culture or in tissues consisting of cell types that contain specialized kinds of microtubule. In spite of this failure to segregate between functionally distinct kinds of microtubule, the fact that isotype-specific amino acid sequences have been strictly conserved over extensive periods of evolutionary time argues persuasively for a functional role for the different tubulin gene products. One possibility is that they are required for specific interactions with microtubule associated proteins (MAPs), and that tubulin isotypes have coevolved with different cell type-specific MAPs with which they must interact. We have tested this hypothesis by examining the distribution of -tubulin isotypes in mammalian cerebellum in relationship to the known patterns of expression of a number of MAPs, and find that these patterns correlate in the case of M 2 and MAP 3, and M 6 and MAP 1 a. These data, plus emerging data based on a structural analysis of tau, MAP 1 b and MAP 2 obtained via sequence determination of cloned cDNAs, are discussed in terms of the possible functional significance of tubulin isotype/MAP interactionsin vivo. 相似文献