全文获取类型
收费全文 | 637篇 |
免费 | 62篇 |
国内免费 | 59篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 23篇 |
2021年 | 35篇 |
2020年 | 37篇 |
2019年 | 27篇 |
2018年 | 27篇 |
2017年 | 32篇 |
2016年 | 17篇 |
2015年 | 19篇 |
2014年 | 44篇 |
2013年 | 51篇 |
2012年 | 27篇 |
2011年 | 21篇 |
2010年 | 18篇 |
2009年 | 25篇 |
2008年 | 35篇 |
2007年 | 15篇 |
2006年 | 19篇 |
2005年 | 25篇 |
2004年 | 17篇 |
2003年 | 12篇 |
2002年 | 17篇 |
2001年 | 14篇 |
2000年 | 11篇 |
1999年 | 4篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 11篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有758条查询结果,搜索用时 163 毫秒
661.
三重RT-PCR同步检测马铃薯多种病毒影响因素 总被引:1,自引:0,他引:1
根据病毒外壳蛋白区序列设计PVX、PVS特异性引物对,根据P1基因区序列设计PVA特异性引物对,应用三重RT-PCR同步检测马铃薯X病毒,马铃薯A病毒及马铃薯S病毒,分别得到562bp、255bp、182bp大小的扩增片段。试验从反转录反应、PCR反应及循环条件3方面讨论了试剂和循环条件对三重RT-PCR同步检测3种病毒的影响。结果表明反转录反应中dNTPs浓度、3种病毒下游引物浓度比例对整个反应影响较大;其次是PCR反应中MgC12浓度和退火温度;反转录时间,循环条件对RT-PCR影响较小。 相似文献
662.
Yuval Mazor Ilanit Greenberg Hila Toporik Oded Beja Nathan Nelson 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2012,367(1608):3400-3405
Recent structural determinations and metagenomic studies shed light on the evolution of photosystem I (PSI) from the homodimeric reaction centre of primitive bacteria to plant PSI at the top of the evolutionary development. The evolutionary scenario of over 3.5 billion years reveals an increase in the complexity of PSI. This phenomenon of ever-increasing complexity is common to all evolutionary processes that in their advanced stages are highly dependent on fine-tuning of regulatory processes. On the other hand, the recently discovered virus-encoded PSI complexes contain a minimal number of subunits. This may reflect the unique selection scenarios associated with viral replication. It may be beneficial for future engineering of productive processes to utilize ‘primitive’ complexes that disregard the cellular regulatory processes and to avoid those regulatory constraints when our goal is to divert the process from its original route. In this article, we discuss the evolutionary forces that act on viral reaction centres and the role of the virus-carried photosynthetic genes in the evolution of photosynthesis. 相似文献
663.
《European journal of cell biology》2023,102(1):151284
Hepatocellular carcinoma (HCC) is the most common type of primary hepatic cancer and is among the major causes of mortality due to cancer. Due to the lack of efficient conventional therapeutic options for this cancer, particularly in advanced cases, novel treatments including immunotherapy have been considered. However, despite the encouraging clinical outcomes after implementing these innovative approaches, such as oncolytic viruses (OVs), adoptive cell therapies (ACT), immune checkpoint blockades (ICBs), and cancer vaccines, several factors have restricted their therapeutic effect. The main concern is the existence of an immunosuppressive tumor microenvironment (TME). Combination of different ICBs or ICBs plus tyrosine kinase inhibitors have shown promising results in overcoming these limiting factors to some extent. Combination of programmed cell death ligand-1 (PD-L1) antibody Atezolizumab and vascular endothelial growth factor (VEGF) antibody Bevacizumab has become the standard of care in the first-line therapy for untestable HCC, approved by regulatory agencies. This paper highlighted a wide overview of the direct and indirect immunotherapeutic strategies proposed for the treatment of HCC patients and the common challenges that have hindered their further clinical applications. 相似文献
664.
665.
《Cell host & microbe》2022,30(8):1124-1138.e8
- Download : Download high-res image (220KB)
- Download : Download full-size image
666.
667.
Sondra Schlesinger 《Molecular biotechnology》1995,3(2):155-165
RNA viruses comprise a wide variety of infectious agents, some of which are the cause of disease in humans, animals, and plants.
Recombinant DNA technology is now making it feasible to modify these genomes and engineer them to express heterologous proteins.
Several different schemes are being employed that depend on the genome organization of the virus and on the strategy of replication
of the particular virus. Several different examples are illustrated and potential uses as well as possible problems are discussed.
In the future reverse genetics may convert some of these viruses from agents of disease to agents of cure. 相似文献
668.
669.
Dr. Caterina De Vinci Paul H. Levine Giancarlo Pizza Hugh H. Fudenberg Perry Orens Gary Pearson Dimitri Viza 《Biotherapy》1996,9(1-3):87-90
Transfer Factor (TF) was used in a placebo controlled pilot study of 20 patients with chronic fatigue syndrome (CFS). Efficacy
of the treatment was evaluated by clinical monitoring and testing for antibodies to Epstein-Barr virus (EBV) and human herpes
virus-6 (HHV-6). Of the 20 patients in the placebo-controlled trial, improvement was observed in 12 patients, generally within
3-6 weeks of beginning treatment. Herpes virus serology seldom correlated with clinical response. This study provided experience
with oral TF, useful in designing a larger placebo-controlled clinical trial. 相似文献
670.
A review of the existing basis for maize stem borer IPM is given and the role of pathogens in the system is evaluated. Survey work outlining the major groups of insect pathogens is described; fungi (Beauveria bassiana and Metarhizium anisopliae), bacteria (Bacillus thuringiensis and Serratia marcesens), and viruses (granuloviruses and cytoplasmic polyhedroviruses) were identified. The presence of other unidentified protozoans, nematodes, fungi and viruses was noted. The virulence of some of the more promising known insect pathogens was explored in preliminary bioassays. Considering the cryptic habits of the insects, and the low input agriculture practiced by the majority of maize farmers in sub-Saharan Africa, Beauveria bassiana isolates possessing the capacity to grow systemically in the maize plant are considered one of the more interesting candidates for development as microbial control agents despite limited control in preliminary trials. Further work should also investigate the potential of pathogens of moderate virulence, such as the protozoans and CPVs. 相似文献