全文获取类型
收费全文 | 9746篇 |
免费 | 764篇 |
国内免费 | 761篇 |
出版年
2024年 | 3篇 |
2023年 | 119篇 |
2022年 | 186篇 |
2021年 | 573篇 |
2020年 | 355篇 |
2019年 | 470篇 |
2018年 | 466篇 |
2017年 | 318篇 |
2016年 | 453篇 |
2015年 | 697篇 |
2014年 | 807篇 |
2013年 | 802篇 |
2012年 | 934篇 |
2011年 | 864篇 |
2010年 | 519篇 |
2009年 | 472篇 |
2008年 | 509篇 |
2007年 | 426篇 |
2006年 | 336篇 |
2005年 | 278篇 |
2004年 | 243篇 |
2003年 | 244篇 |
2002年 | 201篇 |
2001年 | 153篇 |
2000年 | 117篇 |
1999年 | 129篇 |
1998年 | 80篇 |
1997年 | 77篇 |
1996年 | 66篇 |
1995年 | 56篇 |
1994年 | 39篇 |
1993年 | 32篇 |
1992年 | 39篇 |
1991年 | 25篇 |
1990年 | 21篇 |
1989年 | 39篇 |
1988年 | 21篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1985年 | 25篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 18篇 |
1981年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1971年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Yu Bofan Liu Yang Liu Jia Guo Xiaorui Tang Zhonghua 《Journal of Plant Growth Regulation》2022,41(6):2093-2107
Journal of Plant Growth Regulation - In plants, apical hook opening is critical for the post-germination stage and subsequent photomorphogenesis, and this process is activated by a luminous... 相似文献
22.
23.
Erju Tang Xiaolin Shen Jia Wang Xinxiao Sun Qipeng Yuan 《Biotechnology and bioengineering》2020,117(4):1247-1252
myo-Inositol (MI) as a dietary supplement can provide various health benefits. One major challenge to its efficient biosynthesis is to achieve proper distribution of carbon flux between growth and production. Herein, this challenge was overcome by synergetic utilization of glucose and glycerol. Specifically, glycerol was catabolized to support cell growth while glucose was conserved as the building block for MI production. Growth and production were coupled via the phosphotransferase system, and both modules were optimized to achieve efficient production. First, the optimal enzyme combination was established for the production module. It was observed that enhancing the production module resulted in both increased MI production and better cell growth. In addition, glucose was shown to inhibit glycerol utilization via carbon catabolite repression and the inhibition was released by over-expressing glycerol kinase. Furthermore, the inducible promoter was replaced by strong constitutive promoters to avoid inducer use. With these efforts, the final strain produced MI with both high titer and yield. In fed-batch cultivation, 76 g/L of MI was produced, showing scale-up potential. This study provides a promising strategy to achieve rational distribution of carbon flux. 相似文献
24.
25.
Luqing Zhang Humphrey A. Mabwi Norberto J. Palange Ruirui Jia Jun Ma Fatoumata Binta Bah Rajiv Kumar Sah Dan Li Daji Wang Fatoumata Binta Maci Bah Jacques Togo Honghong Jin Luying Ban Xuechao Feng Yaowu Zheng 《PloS one》2015,10(11)
Disconnected (disco)-interacting protein 2 homolog A is a member of the DIP2 protein family encoded by Dip2a gene. Dip2a expression pattern has never been systematically studied. Functions of Dip2a in embryonic development and adult are not known. To investigate Dip2a gene expression and function in embryo and adult, a Dip2a-LacZ mouse model was generated by insertion of β-Gal cDNA after Dip2a promoter using CRISPR/Cas9 technology. Dip2a-LacZ mouse was designed to be a lacZ reporter mouse as well as a Dip2a knockout mouse. Heterozygous mice were used to study endogenous Dip2a expression and homozygotes to study DIP2A-associated structure and function. LacZ staining indicated that Dip2a is broadly expressed in neuronal, reproductive and vascular tissues, as well as in heart, kidney, liver and lung. Results demonstrate that Dip2a is expressed in ectoderm-derived tissues in developing embryos. Adult tissues showed rich staining in neurons, mesenchymal, endothelial, smooth muscle cells and cardiomyocytes by cell types. The expression pattern highly overlaps with FSTL1 and supports previous report that DIP2A to be potential receptor of FSTL1 and its protective roles of cardiomyocytes. Broad and intense embryonic and adult expression of Dip2a has implied their multiple structural and physiological roles. 相似文献
26.
27.
Cyclin E is a regulator of cyclin-dependent protein kinases (Cdks) and is involved in mediating the cell cycle transition from G1 to S phase. Here, we describe a novel function for cyclin E in the long term maintenance of checkpoint arrest in response to replication barriers. Exposure of cells to mitomycin C or UV irradiation, but not ionizing radiation, induces stabilization of cyclin E. Stabilization of cyclin E reduces the activity of Cdk2-cyclin A, resulting in a slowing of S phase progression and arrest. In addition, cyclin E is shown to be required for stabilization of Cdc6, which is required for activation of Chk1 and the replication checkpoint pathway. Furthermore, the stabilization of cyclin E in response to replication fork barriers depends on ATR, but not Nbs1 or Chk1. These results indicate that in addition to its well studied role in promoting cell cycle progression, cyclin E also has a role in regulating cell cycle arrest in response to DNA damage. 相似文献
28.
29.
30.