全文获取类型
收费全文 | 515篇 |
免费 | 45篇 |
专业分类
560篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 16篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 17篇 |
2017年 | 12篇 |
2016年 | 7篇 |
2015年 | 22篇 |
2014年 | 25篇 |
2013年 | 36篇 |
2012年 | 39篇 |
2011年 | 37篇 |
2010年 | 27篇 |
2009年 | 20篇 |
2008年 | 27篇 |
2007年 | 28篇 |
2006年 | 29篇 |
2005年 | 21篇 |
2004年 | 25篇 |
2003年 | 14篇 |
2002年 | 18篇 |
2001年 | 14篇 |
2000年 | 13篇 |
1999年 | 10篇 |
1998年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1984年 | 3篇 |
1982年 | 3篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有560条查询结果,搜索用时 0 毫秒
91.
92.
93.
In six rice cultivars the relative amounts of 55, 26–28 and 15 kDa polypeptides were mostly lower in plants grown for 15 d
under low irradiance than in plants grown under saturating irradiance. This decline in the polypeptides, especially in those
related to light-harvesting chlorophyll proteins, was accompanied with a decrease in the whole chain electron transport and
the photosystem 2 activity. 相似文献
94.
95.
96.
97.
Rajbir Singh Amir Mortazavi Kelly H. Telu Prabakaran Nagarajan David M. Lucas Jennifer M. Thomas-Ahner Steven K. Clinton John C. Byrd Michael A. Freitas Mark R. Parthun 《Nucleic acids research》2013,41(20):9284-9295
Replication-dependent histones are encoded by multigene families found in several large clusters in the human genome and are thought to be functionally redundant. However, the abundance of specific replication-dependent isoforms of histone H2A is altered in patients with chronic lymphocytic leukemia. Similar changes in the abundance of H2A isoforms are also associated with the proliferation and tumorigenicity of bladder cancer cells. To determine whether these H2A isoforms can perform distinct functions, expression of several H2A isoforms was reduced by siRNA knockdown. Reduced expression of the HIST1H2AC locus leads to increased rates of cell proliferation and tumorigenicity. We also observe that regulation of replication-dependent histone H2A expression can occur on a gene-specific level. Specific replication-dependent histone H2A genes are either up- or downregulated in chronic lymphocytic leukemia tumor tissue samples. In addition, discreet elements are identified in the 5′ untranslated region of the HIST1H2AC locus that confer translational repression. Taken together, these results indicate that replication-dependent histone isoforms can possess distinct cellular functions and that regulation of these isoforms may play a role in carcinogenesis. 相似文献
98.
Isolation and characterization of levansucrase-encoding gene from Bacillus amyloliquefaciens 总被引:9,自引:0,他引:9
The gene encoding levansucrase (LVS) from Bacillus amyloliquefaciens (sacB[BamP]) was isolated, sequenced and expressed in Bacillus subtilis. Analysis of the nucleotide sequence of sacB[BamP] reveals extensive homology with that of the B. subtilis LVS-encoding gene in the promoter and coding region. The sacB[BamP] gene cloned in a multicopy plasmid is induced by sucrose in B. subtilis. 相似文献
99.
100.
Viraj Bhat Manish Parashar Hua Liu Nagarajan Kandasamy Mohit Khandekar Scott Klasky Sherif Abdelwahed 《Cluster computing》2007,10(4):365-383
Efficient and robust data streaming services are a critical requirement of emerging Grid applications, which are based on
seamless interactions and coupling between geographically distributed application components. Furthermore the dynamism of
Grid environments and applications requires that these services be able to continually manage and optimize their operation
based on system state and application requirements. This paper presents a design and implementation of such a self-managing
data-streaming service based on online control strategies. A Grid-based fusion workflow scenario is used to evaluate the service
and demonstrate its feasibility and performance.
相似文献
Sherif AbdelwahedEmail: |