全文获取类型
收费全文 | 2065篇 |
免费 | 242篇 |
国内免费 | 64篇 |
出版年
2024年 | 2篇 |
2023年 | 30篇 |
2022年 | 23篇 |
2021年 | 71篇 |
2020年 | 105篇 |
2019年 | 133篇 |
2018年 | 99篇 |
2017年 | 79篇 |
2016年 | 71篇 |
2015年 | 74篇 |
2014年 | 120篇 |
2013年 | 159篇 |
2012年 | 101篇 |
2011年 | 126篇 |
2010年 | 81篇 |
2009年 | 64篇 |
2008年 | 78篇 |
2007年 | 102篇 |
2006年 | 92篇 |
2005年 | 85篇 |
2004年 | 65篇 |
2003年 | 62篇 |
2002年 | 65篇 |
2001年 | 45篇 |
2000年 | 37篇 |
1999年 | 31篇 |
1998年 | 47篇 |
1997年 | 45篇 |
1996年 | 31篇 |
1995年 | 39篇 |
1994年 | 27篇 |
1993年 | 33篇 |
1992年 | 26篇 |
1991年 | 20篇 |
1990年 | 24篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 10篇 |
1986年 | 12篇 |
1985年 | 16篇 |
1984年 | 9篇 |
1983年 | 1篇 |
1981年 | 6篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有2371条查询结果,搜索用时 14 毫秒
1.
2.
3.
4.
5.
6.
E. É. Kolesnikova 《Neurophysiology》2004,36(4):293-309
In this review, modern concepts on molecular mechanisms underlying reception of the oxygen level in natural O2-sensory structures and cellular in vitro models are considered and discussed.Neirofiziologiya/Neurophysiology, Vol.36, No.4, pp.330–347, July–August, 2004. 相似文献
7.
The absorption of lead from loops of small intestinein situ was investigated in rats in which iron absorption was increased by stimuli varying in type, intensity, or duration. Lead
absorption was increased by a short period of severe iron restriction before any change in hematological indices became apparent.
A period of hypoxia, which markedly increased iron absorption, did not influence absorption of lead. An extended period of
moderate iron restriction resulted in a marked reduction in liver iron stores and increased iron absorption throughout the
17-wk experiment. Under these conditions lead absorption was initially also increased, but after 12 wk, when iron intake had
become adequate to meet essential requirements, lead absorption was similar to that in iron-supplemented rats. These results
are discussed in the light of evidence for a receptor-mediated absorption process for iron. 相似文献
8.
9.
Mattia Criscuoli Cristina Ulivieri Irene Filippi Sara Monaci Giuditta Guerrini Bianca Crifò Domiziana De Tommaso Giuliana Pelicci Cosima T. Baldari Cormac T. Taylor Fabio Carraro Antonella Naldini 《Journal of cellular physiology》2020,235(11):8058-8070
Hypoxia occurs in physiological and pathological conditions. T cells experience hypoxia in pathological and physiological conditions as well as in lymphoid organs. Indeed, hypoxia-inducible factor 1α (HIF-1α) affects T cell survival and functions. Rai, an Shc family protein member, exerts pro-survival effects in hypoxic neuroblastoma cells. Since Rai is also expressed in T cells, we here investigated its role in hypoxic T cells. In this work, hypoxia differently affected cell survival, proapoptotic, and metabolic programs in T cells, depending upon Rai expression. By using Jurkat cells stably expressing Rai and splenocytes from Rai−/−mice, we demonstrated that Rai promotes T cell survival and affects cell metabolism under hypoxia. Upon exposure to hypoxia, Jurkat T cells expressing Rai show (a) higher HIF-1α protein levels; (b) a decreased cell death and increased Akt/extracellular-signal-regulated kinase phosphorylation; (c) a decreased expression of proapoptotic markers, including caspase activities and poly(ADP-ribose) polymerase cleavage; (d) an increased glucose and lactate metabolism; (e) an increased activation of nuclear factor-kB pathway. The opposite effects were observed in hypoxic splenocytes from Rai−/−mice. Thus, Rai plays an important role in hypoxic signaling and may be relevant in the protection of T cells against hypoxia. 相似文献
10.
Qiangnu Zhang Lijun Qiao Juan Liao Quan Liu Pengyu Liu Liping Liu 《Journal of cellular and molecular medicine》2021,25(8):3772-3784
Due to the lack of a suitable gene signature, it is difficult to assess the hypoxic exposure of HCC tissues. The clinical value of assessing hypoxia in HCC is short of tissue-level evidence. We tried to establish a robust and HCC-suitable hypoxia signature using microarray analysis and a robust rank aggregation algorithm. Based on the hypoxia signature, we obtained a hypoxia-associated HCC subtypes system using unsupervised hierarchical clustering and a hypoxia score system was provided using gene set variation analysis. A novel signature containing 21 stable hypoxia-related genes was constructed to effectively indicate the exposure of hypoxia in HCC tissues. The signature was validated by qRT-PCR and compared with other published hypoxia signatures in multiple large-size HCC cohorts. The subtype of HCC derived from this signature had different prognosis and other clinical characteristics. The hypoxia score obtained from the signature could be used to indicate clinical characteristics and predict prognoses of HCC patients. Moreover, we reveal a landscape of immune microenvironments in patients with different hypoxia score. In conclusion, we identified a novel HCC-suitable 21-gene hypoxia signature that could be used to estimate the hypoxia exposure in HCC tissues and indicated prognosis and a series of important clinical features in HCCs. It may enable the development of personalized counselling or treatment strategies for HCC patients with different levels of hypoxia exposure. 相似文献