全文获取类型
收费全文 | 8548篇 |
免费 | 538篇 |
国内免费 | 310篇 |
出版年
2024年 | 15篇 |
2023年 | 101篇 |
2022年 | 129篇 |
2021年 | 217篇 |
2020年 | 242篇 |
2019年 | 375篇 |
2018年 | 308篇 |
2017年 | 212篇 |
2016年 | 181篇 |
2015年 | 233篇 |
2014年 | 484篇 |
2013年 | 553篇 |
2012年 | 362篇 |
2011年 | 473篇 |
2010年 | 325篇 |
2009年 | 292篇 |
2008年 | 323篇 |
2007年 | 387篇 |
2006年 | 309篇 |
2005年 | 272篇 |
2004年 | 241篇 |
2003年 | 220篇 |
2002年 | 206篇 |
2001年 | 167篇 |
2000年 | 145篇 |
1999年 | 180篇 |
1998年 | 146篇 |
1997年 | 161篇 |
1996年 | 158篇 |
1995年 | 141篇 |
1994年 | 116篇 |
1993年 | 84篇 |
1992年 | 129篇 |
1991年 | 111篇 |
1990年 | 102篇 |
1989年 | 113篇 |
1988年 | 114篇 |
1987年 | 97篇 |
1986年 | 98篇 |
1985年 | 96篇 |
1984年 | 140篇 |
1983年 | 103篇 |
1982年 | 138篇 |
1981年 | 101篇 |
1980年 | 84篇 |
1979年 | 69篇 |
1978年 | 34篇 |
1977年 | 34篇 |
1976年 | 22篇 |
1974年 | 13篇 |
排序方式: 共有9396条查询结果,搜索用时 31 毫秒
1.
Sebastián Moran Miguel Vizoso Anna Martinez-Cardús Antonio Gomez Xavier Matías-Guiu Sebastián M Chiavenna Andrés G Fernandez Manel Esteller 《Epigenetics》2014,9(6):829-833
A formalin-fixed paraffin-embedded (FFPE) sample usually yields highly degraded DNA, which limits the use of techniques requiring high-quality DNA, such as Infinium Methylation microarrays. To overcome this restriction, we have applied an FFPE restoration procedure consisting of DNA repair and ligation processes in a set of paired fresh-frozen (FF) and FFPE samples. We validated the FFPE results in comparison with matched FF samples, enabling us to use FFPE samples on the Infinium HumanMethylation450 Methylation array. 相似文献
2.
3.
4.
Copper is an essential yet toxic metal ion. To satisfy cellular requirements, while, at the same time, minimizing toxicity,
complex systems of copper trafficking have evolved in all cell types. The best conserved and most widely distributed of these
involve Atx1-like chaperones and P1B-type ATPase transporters. Here, we discuss current understanding of how these chaperones bind Cu(I) and transfer it to the
Atx1-like N-terminal domains of their cognate transporter. 相似文献
5.
Charles E. Wenner John C. Cheney L. David Tomei 《Journal of cellular biochemistry》1981,15(2):161-168
The introduction of either PGF2α (10?7 M) or TPA (10?7 M) stimulated, ouabain-sensitive 86Rb+ influx at 30 min in postconfluent 3T3-4 mouse fibroblast cultures by 117% and 124%, respectively. Both TPA and PGF2α at these concentrations stimulated the incorporation of 3H-TdR into DNA. TPA had the greatest stimulatory effect, which was similar to that obtained with 10% fetal calf serum. In accord with the idea that modulation of membrane processes such as Na+/K+ pump activity in fibroblasts may reflect important events related to the initiation of DNA synthesis, it was observed that in both 3T3-4 and C3H-1 0T½ cells there were parallel increases in 3H-TdR incorporation and ouabain-sensitive 86Rb+ influxes with 10?7 M TPA, whereas PGF2α stimulated a significant increase in 3H-TdR incorporation in 3T3-4 but not C3H-10T½ cells and only marginal increases in ouabain-sensitive 86Rb+ influx in both. Therefore, although there appears to be a close correlation between Na+/K+ pump activation and subsequent S-phase entry following TPA stimulation, a similar correlation for PGF2α cannot be confirmed. 相似文献
6.
The CD genome species in the genus Oryza are endemic to Latin America, including O. alta, O. grandiglumis and O. latifolia. Origins and phylogenetic relationship of these species have long been in dispute and are still ambiguous due to their homogeneous genome type, similar morphological characteristics and overlapping distribution. In the present study, we sequenced two chloroplast fragments (matK and trnL-trnF) and portions of three nuclear genes (Adh1, Adh2 and GPA1) from sixteen accessions representing seven species with the C, CD, and E genomes, as well as one G genome species as the outgroup. Phylogenetic analyses using parsimony and distance methods strongly supported that the CD genome originated from a single hybridization event, and that the C genome species (O. officinalis or O. rhizomatis instead of O. eichingeri) served as the maternal parent while the E genome species (O. australiensis) was the paternal donor during the formation of CD genome. In addition, the consistent phylogenetic relationships among the CCDD species indicated that significant divergence existed between O. latifolia and the other two (O. alta and O. grandiglumis), which corroborated the suggestion of treating the latter two as a single species or as taxa within species.We thank Tao Sang of Michigan State University (East Lansing, USA) and Bao-rong Lu of Fudan University (Shanghai, China) for their encouragement and assistance. We are also grateful to the International Rice Research Institute (Manila, Philippines) for providing plant material for this study. This research was supported by the Chinese Academy of Sciences (kscxz-sw-101A), the National Natural Science Foundation of China (30025005) and the Program for Key International S & T Cooperation Project of P. R. China (2001CB711103). 相似文献
7.
Rita Padányi Yuning Xiong Géza Antalffy Krisztina Lór Katalin Pászty Emanuel E. Strehler ágnes Enyedi 《The Journal of biological chemistry》2010,285(41):31704-31712
The membrane localization of the plasma membrane Ca2+-ATPase isoform 2 (PMCA2) in polarized cells is determined by alternative splicing; the PMCA2w/b splice variant shows apical localization, whereas the PMCA2z/b and PMCA2x/b variants are mostly basolateral. We previously reported that PMCA2b interacts with the PDZ protein Na+/H+ exchanger regulatory factor 2 (NHERF2), but the role of this interaction for the specific membrane localization of PMCA2 is not known. Here we show that co-expression of NHERF2 greatly enhanced the apical localization of GFP-tagged PMCA2w/b in polarized Madin-Darby canine kidney cells. GFP-PMCA2z/b was also redirected to the apical membrane by NHERF2, whereas GFP-PMCA2x/b remained exclusively basolateral. In the presence of NHERF2, GFP-PMCA2w/b co-localized with the actin-binding protein ezrin even after disruption of the actin cytoskeleton by cytochalasin D or latrunculin B. Surface biotinylation and fluorescence recovery after photobleaching experiments demonstrated that NHERF2-mediated anchorage to the actin cytoskeleton reduced internalization and lateral mobility of the pump. Our results show that the specific interaction with NHERF2 enhances the apical concentration of PMCA2w/b by anchoring the pump to the apical membrane cytoskeleton. The data also suggest that the x/b splice form of PMCA2 contains a dominant lateral targeting signal, whereas the targeting and localization of the z/b form are more flexible and not fully determined by intrinsic sequence features. 相似文献
8.
9.
《Developmental cell》2022,57(14):1694-1711.e7
- Download : Download high-res image (191KB)
- Download : Download full-size image
10.