全文获取类型
收费全文 | 3838篇 |
免费 | 249篇 |
国内免费 | 266篇 |
出版年
2023年 | 69篇 |
2022年 | 102篇 |
2021年 | 80篇 |
2020年 | 83篇 |
2019年 | 101篇 |
2018年 | 128篇 |
2017年 | 93篇 |
2016年 | 82篇 |
2015年 | 75篇 |
2014年 | 262篇 |
2013年 | 309篇 |
2012年 | 180篇 |
2011年 | 215篇 |
2010年 | 169篇 |
2009年 | 192篇 |
2008年 | 222篇 |
2007年 | 248篇 |
2006年 | 180篇 |
2005年 | 160篇 |
2004年 | 121篇 |
2003年 | 115篇 |
2002年 | 89篇 |
2001年 | 50篇 |
2000年 | 68篇 |
1999年 | 81篇 |
1998年 | 61篇 |
1997年 | 55篇 |
1996年 | 61篇 |
1995年 | 53篇 |
1994年 | 55篇 |
1993年 | 50篇 |
1992年 | 32篇 |
1991年 | 31篇 |
1990年 | 20篇 |
1989年 | 24篇 |
1988年 | 17篇 |
1987年 | 17篇 |
1986年 | 16篇 |
1985年 | 27篇 |
1984年 | 50篇 |
1983年 | 33篇 |
1982年 | 36篇 |
1981年 | 30篇 |
1980年 | 39篇 |
1979年 | 35篇 |
1978年 | 21篇 |
1977年 | 25篇 |
1976年 | 16篇 |
1974年 | 22篇 |
1973年 | 19篇 |
排序方式: 共有4353条查询结果,搜索用时 15 毫秒
211.
212.
Ownership can evolve in potentially any species. Drawing on insights from across disciplines, we distinguish between possession and ownership and present species‐neutral criteria for ownership, defined as respect for possession. We use a variant of the tug‐of‐war evolutionary game to demonstrate how ownership can evolve in the form of a new, biologically realistic strategy, Restraint With Retaliation (RWR). In our game, resource holding potential (RHP) is assumed to be equal between interactants, and resource holding asymmetry determines whether ownership is adaptive. RWR will be evolutionarily stable when the ratio of resource holdings between interactants is relatively low, but not when this ratio is sufficiently high. We offer RWR as one evolutionary route to ownership among many, and discuss how ownership unites previously described behavioural phenomena across taxa. We propose that some but not all mechanisms of territory formation and maintenance can be considered ownership, and show that territories are not the only resources that can be owned. We argue that ownership can be a powerful cooperative solution to tragedies of the commons and problems of collective action throughout the biological world. We advance recent scholarship that has begun to investigate the biological importance of ownership, and we call for a comprehensive account of its evolutionary logic and taxonomic distribution. We propose that ownership should be considered a fundamental, unifying biological phenomenon. 相似文献
213.
目的:探讨多囊性肾病基因1(polystic kidney disease,PKD1)多态位点rs8049367与抑癌基因P53(anti-oncogene P53)多态位点rs4791774单核苷酸多态性与中国北方人群非综合征性唇腭裂(NSCL/P)的相关性。方法:运用聚合酶链式反应-连接酶检测反应(PCR-LDR)的检测方法,对602例NSCL/P患者和510例对照人群的PKD1基因的rs8049367位点和抑癌基因P53的rs4791774位点进行基因分型。利用SPSS12.0软件分析PKD1基因,抑癌基因P53多态性与NSCL/P的相关性。结果:rs8049367位点和rs4791774位点基因型及基因频率在两组的分布中差异无统计学意义(P0.05)。结论:PKD1基因的rs8049367位点和抑癌基因P53的rs4791774位点单核苷酸多态性可能与中国北方人群非综合征性唇腭裂的发生无相关性。 相似文献
214.
随着质谱技术及各种定量方法的不断完善和发展,定量蛋白质组学的方法不断地被应用到各类生物学研究中。蛋白质组学定性定量数据的处理主要通过一些多功能的商业化或者开源软件来进行,如常用的数据分析软件Proteome Discoverer和Maxquant。但是在通过化学标记对蛋白质N末端乙酰化程度进行定量这一方面,Proteome Discoverer和Maxquant在一定程度上存在准确性不高和完整度不够的问题。于是本研究针对自己的实验特点,通过Java算法编写了相应的定量程序Acequant来完成N末端乙酰化程度的相对定量。本研究将该程序在已有相关报道的He La cell上进行了验证,Acequant共定量到1 587个蛋白质N末端,而Proteome Discoverer和Maxquant分别只定量到42个和306个N末端。同时,手动验证原始图谱也证实了Acequant定量的准确性更好。于是,本研究将此方法进一步应用到秀丽隐杆线虫N末端乙酰化的研究中,并初步发现了线虫整体的N末端乙酰化状态,为进一步的N末端研究提供了支持。 相似文献
215.
Phosphoinositide 3‐kinase gamma (PI3Kγ) draws an increasing attention due to its link with deadly cancer, chronic inflammation and allergy. But the development of PI3Kγ selective inhibitors is still a challenging endeavor because of the high sequence homology with the other PI3K isoforms. In order to acquire valuable information about the interaction mechanism between potent inhibitors and PI3Kγ, a series of PI3Kγ isoform‐selective inhibitors were analyzed by a systematic computational method, combining 3D‐QSAR, molecular docking, molecular dynamic (MD) simulations, free energy calculations and decomposition. The general structure–activity relationships were revealed and some key residues relating to selectivity and high activity were highlighted. It provides precious guidance for rational virtual screening, modification and design of selective PI3Kγ inhibitors. Finally, ten novel inhibitors were optimized and P10 showed satisfactory predicted bioactivity, demonstrating the feasibility to develop potent PI3Kγ inhibitors through this computational modeling and optimization. 相似文献
216.
Sihua Liu Hongyun Liu Keke Zhang Xueping Li Yuqin Duan Zhiyun Wang Tao Wang 《中国病毒学》2019,34(5):572-582
Severe fever with thrombocytopenia syndrome(SFTS) is an emerging hemorrhagic fever disease caused by SFTSV, a newly discovered phlebovirus that is named after the disease. Currently, no effective vaccines or drugs are available for use against SFTSV infection, as our understanding of the viral pathogenesis is limited. Bortezomib(PS-341), a dipeptideboronic acid analog, is the first clinically approved proteasome inhibitor for use in humans. In this study, the antiviral efficacy of PS-341 against SFTSV infection was tested in human embryonic kidney HEK293 T(293 T) cells. We employed four different assays to analyze the antiviral ability of PS-341 and determined that PS-341 inhibited the proliferation of SFTSV in 293 T cells under various treatment conditions. Although PS-341 did not affect the virus absorption, PS-341 treatment within a non-toxic concentration range resulted in a significant reduction of progeny viral titers in infected cells.Dual-luciferase reporter assays and Western blot analysis revealed that PS-341 could reverse the SFTSV-encoded nonstructural protein(NS) mediated degradation of retinoic acid-inducible gene-1(RIG-I), thereby antagonizing the inhibitory effect of NSs on interferons and blocking virus replication. In addition, we observed that inhibition of apoptosis promotes virus replication. These results indicate that targeting of cellular interferon pathways and apoptosis during acute infection might serve as the bases of future therapeutics for the treatment of SFTSV infections. 相似文献
217.
《Molecular & cellular proteomics : MCP》2019,18(3):477-489
Highlights
- •Developed a data processing pipeline to format phosphopeptide identifications.
- •Identified the preferred substrate motif for FLT3 and mutant kinases.
- •Designed and validated a panel of pan-FTL3 artificial substrates.
- •Monitored FLT3 and mutant kinase activity through FAStide phosphorylation.
218.
The experimental and clinical data about antibodies against environmental chemical carcinogens and endogenous steroids are represented. The conception of immunomodulation of carcinogens- and steroids-dependent human diseases is proposed. It is postulated that antibodies to polycyclic aromatic hydrocarbons and heterocyclic amines in cooperation with antibodies to cholesterol, sex hormones, mineralo- and glucocorticoids stimulate or inhibit cancer, malformation, cardiovascular and autoimmune diseases depending on their personal combination. It is recommended to use immunoassay of these antibodies for the human diseases prediction. The alternative approaches for prevention using the probiotics transformed by anti-carcinogen antibodies are substantiated. 相似文献
219.
220.
《Bioorganic & medicinal chemistry》2019,27(16):3546-3550
Previously we have reported on a series of pyridine-3-carboxamide inhibitors of DNA gyrase and DNA topoisomerase IV that were designed using a computational de novo design approach and which showed promising antibacterial properties. Herein we describe the synthesis of additional examples from this series aimed specifically at DNA gyrase, along with crystal structures confirming the predicted mode of binding and in vitro ADME data which describe the drug-likeness of these compounds. 相似文献