全文获取类型
收费全文 | 3285篇 |
免费 | 301篇 |
国内免费 | 267篇 |
出版年
2024年 | 21篇 |
2023年 | 214篇 |
2022年 | 188篇 |
2021年 | 298篇 |
2020年 | 218篇 |
2019年 | 209篇 |
2018年 | 164篇 |
2017年 | 123篇 |
2016年 | 124篇 |
2015年 | 179篇 |
2014年 | 211篇 |
2013年 | 234篇 |
2012年 | 140篇 |
2011年 | 154篇 |
2010年 | 107篇 |
2009年 | 122篇 |
2008年 | 134篇 |
2007年 | 131篇 |
2006年 | 117篇 |
2005年 | 94篇 |
2004年 | 72篇 |
2003年 | 75篇 |
2002年 | 67篇 |
2001年 | 64篇 |
2000年 | 32篇 |
1999年 | 38篇 |
1998年 | 23篇 |
1997年 | 27篇 |
1996年 | 28篇 |
1995年 | 23篇 |
1994年 | 28篇 |
1993年 | 32篇 |
1992年 | 18篇 |
1991年 | 23篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 11篇 |
1983年 | 11篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1975年 | 5篇 |
1973年 | 2篇 |
排序方式: 共有3853条查询结果,搜索用时 937 毫秒
991.
Saswati Panda Jing Zhang Nguan Soon Tan Bow Ho Jeak Ling Ding 《The EMBO journal》2013,32(22):2905-2919
For nearly five decades since its discovery, the role of natural IgG, which pre-exists in neonates and uninfected individuals, has remained unclear due to the general perception that natural antibodies lack affinity for pathogens. Here, we show for the first time that natural IgG recognizes a spectrum of bacteria through lectins like ficolin and mannose binding lectin (MBL). Infection-inflammation condition markedly increased the affinity of natural IgG for bacteria associated with ficolins. After opsonization with IgG:ficolin complex, the bacteria were phagocytosed by monocytes via FcγRI. Infection of C3−/− mice indicated that the natural IgG-mediated immune complex was formed independently of C3. AID−/− mice lacking IgG were susceptible to infection, unless reconstituted with natural IgG. Thus, we have proven that natural IgG is not quiescent; rather, it plays a vital and immediate role in immune defense. Our findings provide a fresh perspective on natural antibodies, opening new avenues to explore host–microbe interaction. 相似文献
992.
993.
Fu Jie ZHANG Jennifer PAN Lan YU Yi WEN Yan ZHAO 《Cell research》2005,15(11):877-882
China's Free ART Program was initiated in 2002 as an emergency response to save and improve the lives of AIDS patients living mainly in impoverished rural regions of central China. With little experience in HIV/AIDS treatment and care and resource limitations, China's efforts to provide widespread access to free antiretroviral therapy has been a process fraught with difficulty. However, the Free ART Program is progressing from an emergency response to a standardized treatment and care system. The development of national guidelines, training programs, a laboratory support network, a national patient database, programs for special populations such as children and patients living with coinfections, and operational research has improved the scope and quality of the free treatment program. As of June 30, 2005, a total of 19,456 patients in 28 provinces, autonomous regions, and special municipalities had received free ART. Challenges stemming from the nature of China's health system and patient population persist, but with strong government support and a diverse set of resources, China has the capacity to overcome these challenges and to provide nationwide access to high quality treatment and care. 相似文献
994.
995.
996.
Barbara Tschirren Martin Andersson Kristin Scherman Helena Westerdahl Peer R. E. Mittl Lars R?berg 《Proceedings. Biological sciences / The Royal Society》2013,280(1759)
The discovery of the key role of Toll-like receptors (TLRs) in initiating innate immune responses and modulating adaptive immunity has revolutionized our understanding of vertebrate defence against pathogens. Yet, despite their central role in pathogen recognition and defence initiation, there is little information on how variation in TLRs influences disease susceptibility in natural populations. Here, we assessed the extent of naturally occurring polymorphisms at TLR2 in wild bank voles (Myodes glareolus) and tested for associations between TLR2 variants and infection with Borrelia afzelii, a common tick-transmitted pathogen in rodents and one of the causative agents of human Lyme disease. Bank voles in our population had 15 different TLR2 haplotypes (10 different haplotypes at the amino acid level), which grouped in three well-separated clusters. In a large-scale capture–mark–recapture study, we show that voles carrying TLR2 haplotypes of one particular cluster (TLR2c2) were almost three times less likely to be Borrelia infected than animals carrying other haplotypes. Moreover, neutrality tests suggested that TLR2 has been under positive selection. This is, to our knowledge, the first demonstration of an association between TLR polymorphism and parasitism in wildlife, and a striking example that genetic variation at innate immune receptors can have a large impact on host resistance. 相似文献
997.
998.
Lauren B. Rodda Jason Netland Laila Shehata Kurt B. Pruner Peter A. Morawski Christopher D. Thouvenel Kennidy K. Takehara Julie Eggenberger Emily A. Hemann Hayley R. Waterman Mitchell L. Fahning Yu Chen Malika Hale Jennifer Rathe Caleb Stokes Samuel Wrenn Brooke Fiala Lauren Carter Marion Pepper 《Cell》2021,184(1):169-183.e17
999.
Monica Neagu Daniela Calina Anca Oana Docea Carolina Constantin Tommaso Filippini Marco Vinceti Nikolaos Drakoulis Konstantinos Poulas Taxiarchis Konstantinos Nikolouzakis Demetrios A. Spandidos Aristidis Tsatsakis 《Journal of cellular and molecular medicine》2021,25(10):4523-4533
The outbreak of the coronavirus disease 2019 (COVID-19) has gathered 1 year of scientific/clinical information. This informational asset should be thoroughly and wisely used in the coming year colliding in a global task force to control this infection. Epidemiology of this infection shows that the available estimates of SARS-CoV-2 infection prevalence largely depended on the availability of molecular testing and the extent of tested population. Within molecular diagnosis, the viability and infectiousness of the virus in the tested samples should be further investigated. Moreover, SARS-CoV-2 has a genetic normal evolution that is a dynamic process. The immune system participates to the counterattack of the viral infection by pathogen elimination, cellular homoeostasis, tissue repair and generation of memory cells that would be reactivated upon a second encounter with the same virus. In all these stages, we still have knowledge to be gathered regarding antibody persistence, protective effects and immunological memory. Moreover, information regarding the intense pro-inflammatory action in severe cases still lacks and this is important in stratifying patients for difficult to treat cases. Without being exhaustive, the review will cover these important issues to be acknowledged to further advance in the battle against the current pandemia. 相似文献
1000.
Timothy N. Hoang Maria Pino Arun K. Boddapati Elise G. Viox Carly E. Starke Amit A. Upadhyay Sanjeev Gumber Michael Nekorchuk Kathleen Busman-Sahay Zachary Strongin Justin L. Harper Gregory K. Tharp Kathryn L. Pellegrini Shannon Kirejczyk Keivan Zandi Sijia Tao Tristan R. Horton Elizabeth N. Beagle Mirko Paiardini 《Cell》2021,184(2):460-475.e21