全文获取类型
收费全文 | 12072篇 |
免费 | 776篇 |
国内免费 | 7篇 |
出版年
2024年 | 15篇 |
2023年 | 38篇 |
2022年 | 111篇 |
2021年 | 232篇 |
2020年 | 131篇 |
2019年 | 205篇 |
2018年 | 295篇 |
2017年 | 244篇 |
2016年 | 424篇 |
2015年 | 615篇 |
2014年 | 748篇 |
2013年 | 799篇 |
2012年 | 1066篇 |
2011年 | 1042篇 |
2010年 | 649篇 |
2009年 | 498篇 |
2008年 | 789篇 |
2007年 | 677篇 |
2006年 | 612篇 |
2005年 | 559篇 |
2004年 | 570篇 |
2003年 | 452篇 |
2002年 | 361篇 |
2001年 | 355篇 |
2000年 | 327篇 |
1999年 | 227篇 |
1998年 | 89篇 |
1997年 | 77篇 |
1996年 | 49篇 |
1995年 | 48篇 |
1994年 | 38篇 |
1993年 | 29篇 |
1992年 | 83篇 |
1991年 | 54篇 |
1990年 | 44篇 |
1989年 | 48篇 |
1988年 | 27篇 |
1987年 | 28篇 |
1986年 | 21篇 |
1985年 | 23篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 9篇 |
1978年 | 15篇 |
1975年 | 13篇 |
1974年 | 11篇 |
1970年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
982.
983.
984.
985.
986.
Koyi Choi Sabrina Batke Barnabas Szakal Jonathan Lowther Fanfan Hao Prabha Sarangi Dana Branzei Helle D. Ulrich Xiaolan Zhao 《Nucleic acids research》2015,43(5):2666-2677
Many genome maintenance factors have multiple enzymatic activities. In most cases, how their distinct activities functionally relate with each other is unclear. Here we examined the conserved budding yeast Rad5 protein that has both ubiquitin ligase and DNA helicase activities. The Rad5 ubiquitin ligase activity mediates PCNA poly-ubiquitination and subsequently recombination-based DNA lesion tolerance. Interestingly, the ligase domain is embedded in a larger helicase domain comprising seven consensus motifs. How features of the helicase domain influence ligase function is controversial. To clarify this issue, we use genetic, 2D gel and biochemical analyses and show that a Rad5 helicase motif important for ATP binding is also required for PCNA poly-ubiquitination and recombination-based lesion tolerance. We determine that this requirement is due to a previously unrecognized contribution of the motif to the PCNA and ubiquitination enzyme interaction, and not due to its canonical role in supporting helicase activity. We further show that Rad5′s helicase-mediated contribution to replication stress survival is separable from recombination. These findings delineate how two Rad5 enzymatic domains concertedly influence PCNA modification, and unveil their discrete contributions to stress tolerance. 相似文献
987.
988.
Kyung?Min?Lee Okkyoung?Choi Ki-Yeon?Kim Han?Min?Woo Yunje?Kim Sung?Ok?Han Byoung-In?Sang Youngsoon?UmEmail author 《Biotechnology letters》2015,37(9):1837-1844
Objective
To produce butyric acid from red algae such as Gelidium amansii in which galactose is a main carbohydrate, microorganisms utilizing galactose and tolerating inhibitors in hydrolysis including levulinic acid and 5-hydroxymethylfurfural (HMF) are required.Results
A newly isolated bacterium, Clostridium sp. S1 produced butyric acid not only from galactose as the sole carbon source but also from a mixture of galactose and glucose through simultaneous utilization. Notably, Clostridium sp. S1 produced butyric acid and a small amount of acetic acid with the butyrate:acetate ratio of 45.4:1 and it even converted acetate to butyric acid. Clostridium sp. S1 tolerated 0.5–2 g levulinic acid/l and recovered from HMF inhibition at 0.6–2.5 g/l, resulting in 85–92 % butyric acid concentration of the control culture. When acid-pretreated G. amansii hydrolysate was used, Clostridium sp. S1 produced 4.83 g butyric acid/l from 10 g galactose/l and 1 g glucose/l.Conclusion
Clostridium sp. S1 produces butyric acid from red algae due to its characteristics in sugar utilization and tolerance to inhibitors, demonstrating its advantage as a red algae-utilizing microorganism.989.
990.