全文获取类型
收费全文 | 4720篇 |
免费 | 403篇 |
国内免费 | 328篇 |
出版年
2024年 | 12篇 |
2023年 | 35篇 |
2022年 | 144篇 |
2021年 | 257篇 |
2020年 | 182篇 |
2019年 | 214篇 |
2018年 | 219篇 |
2017年 | 151篇 |
2016年 | 201篇 |
2015年 | 312篇 |
2014年 | 381篇 |
2013年 | 360篇 |
2012年 | 450篇 |
2011年 | 373篇 |
2010年 | 227篇 |
2009年 | 236篇 |
2008年 | 273篇 |
2007年 | 209篇 |
2006年 | 170篇 |
2005年 | 141篇 |
2004年 | 117篇 |
2003年 | 129篇 |
2002年 | 115篇 |
2001年 | 80篇 |
2000年 | 72篇 |
1999年 | 53篇 |
1998年 | 30篇 |
1997年 | 35篇 |
1996年 | 37篇 |
1995年 | 44篇 |
1994年 | 35篇 |
1993年 | 26篇 |
1992年 | 28篇 |
1991年 | 23篇 |
1990年 | 17篇 |
1989年 | 14篇 |
1988年 | 8篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有5451条查询结果,搜索用时 15 毫秒
971.
972.
Yu Shang Li Li Tengfei Zhang Qingping Luo Qingzhong Yu Zhe Zeng Lintao Li Miaomiao Jia Guoyi Tang Sanlin Fan Qin Lu Wenting Zhang Yuhan Xue Hongling Wang Wei Liu Hongcai Wang Rongrong Zhang Chan Ding Huabin Shao Guoyuan Wen 《PLoS pathogens》2022,18(6)
The development of thermostable vaccines can relieve the bottleneck of existing vaccines caused by thermal instability and subsequent poor efficacy, which is one of the predominant reasons for the millions of deaths caused by vaccine-preventable diseases. Research into the mechanism of viral thermostability may provide strategies for developing thermostable vaccines. Using Newcastle disease virus (NDV) as model, we identified the negative surface charge of attachment glycoprotein as a novel determinant of viral thermostability. It prevented the temperature-induced aggregation of glycoprotein and subsequent detachment from virion surface. Then structural stability of virion surface was improved and virus could bind to and infect cells efficiently after heat-treatment. Employing the approach of surface charge engineering, thermal stability of NDV and influenza A virus (IAV) vaccines was successfully improved. The increase in the level of vaccine thermal stability was determined by the value-added in the negative surface charge of the attachment glycoprotein. The engineered live and inactivated vaccines could be used efficiently after storage at 37°C for at least 10 and 60 days, respectively. Thus, our results revealed a novel surface-charge-mediated link between HN protein and NDV thermostability, which could be used to design thermal stable NDV and IAV vaccines rationally. 相似文献
973.
974.
Zhenzhen Chen Lan Huang Kaili Wang Lulu Zhang Xiang Zhong Zhongyi Yan Benyu Liu Pingping Zhu 《中国科学:生命科学英文版》2022,65(9):1840-1854
Liver cancer is highly heterogeneous,and the tumor tissue harbors a variety of cell types.Liver tumor initiating cells(TICs) well contribute to tumor heterogeneity and account for tumor initiation and metastasis,but the molecular mechanisms of liver TIC self-renewal are elusive.Here,we identified a functional read-through rt-circRNA,termed rtcisE2 F,that is highly expressed in liver cancer and liver TICs.rtcisE2 F plays essential roles in the self-renewal and activities of liver TICs.rtcisE2 F t... 相似文献
975.
The paper reports 13 species from Yaoluoping National Nature Reserve,Anhui,China,including a new species and a new subspecies,Tipula (Emodotipula) alexanderi Men,sp.nov.and Nephrotoma impigra anqingensis Men,subsp.nov.The female of Libnotes (Libnotes) pseudonohirai Men,2015 is described and illustrated for the first time.The males of Holorusia henana Yang,1999 and Tipula (Vestiplex)jiangi Yang & Yang,1991 are redescribed and illustrated with new morphological characters.A key to all species is provided. 相似文献
976.
977.
用于生产重组蛋白药物的抗凋亡CHO宿主细胞株的建立 总被引:5,自引:0,他引:5
哺乳动物工程细胞在大规模培养生产重组蛋白时很容易发生细胞凋亡,从而导致生产过程提前终止,造成生产成本高昂。细胞代谢产物氨已被证明可以促进细胞凋亡,而线粒体膜整合蛋白Bcl-2可以通过促进线粒体膜完整性而抑制细胞凋亡。本实验应用谷氨酰胺合成酶加压系统在CHO工程细胞中高效表达中国仓鼠Bcl-2蛋白,使细胞具有抗凋亡能力的同时,利用谷氨酸和氨合成谷氨酰胺而有效降低培养基中氨的含量,从而达到抑制细胞凋亡的目的。 相似文献
978.
979.
麦套春棉主要害虫和天敌的生态位研究 总被引:5,自引:2,他引:5
调查了麦套着棉不同时期内,棉株上、中、下部棉蚜AphisgossypiiGover、棉叶螨TetranychustruncatusEhara、棉铃虫Helicoverpaarmigera(Hubner)和其主要天敌的数量。求得各期害虫与害虫、害虫与天敌、天敌与天敌之间的生态位宽度和重叠指数,并分析了它们彼此在空间上的竞争关系。 相似文献
980.
Detection of the synergetic effects between variants, such as single-nucleotide polymorphisms (SNPs), is crucial for understanding the genetic characters of complex diseases. Here, we proposed a two-step approach to detect differentially inherited SNP modules (synergetic SNP units) from a SNP network. First, SNP-SNP interactions are identified based on prior biological knowledge, such as their adjacency on the chromosome or degree of relatedness between the functional relationships of their genes. These interactions form SNP networks. Second, disease-risk SNP modules (or sub-networks) are prioritised by their differentially inherited properties in IBD (Identity by Descent) profiles of affected and unaffected sibpairs. The search process is driven by the disease information and follows the structure of a SNP network. Simulation studies have indicated that this approach achieves high accuracy and a low false-positive rate in the identification of known disease-susceptible SNPs. Applying this method to an alcoholism dataset, we found that flexible patterns of susceptible SNP combinations do play a role in complex diseases, and some known genes were detected through these risk SNP modules. One example is GRM7, a known alcoholism gene successfully detected by a SNP module comprised of two SNPs, but neither of the two SNPs was significantly associated with the disease in single-locus analysis. These identified genes are also enriched in some pathways associated with alcoholism, including the calcium signalling pathway, axon guidance and neuroactive ligand-receptor interaction. The integration of network biology and genetic analysis provides putative functional bridges between genetic variants and candidate genes or pathways, thereby providing new insight into the aetiology of complex diseases. 相似文献