全文获取类型
收费全文 | 3096103篇 |
免费 | 256523篇 |
国内免费 | 74664篇 |
出版年
2021年 | 41528篇 |
2020年 | 33252篇 |
2019年 | 41035篇 |
2018年 | 48110篇 |
2017年 | 42927篇 |
2016年 | 60518篇 |
2015年 | 82386篇 |
2014年 | 100239篇 |
2013年 | 135735篇 |
2012年 | 151262篇 |
2011年 | 151442篇 |
2010年 | 104128篇 |
2009年 | 97532篇 |
2008年 | 129806篇 |
2007年 | 130326篇 |
2006年 | 121907篇 |
2005年 | 114103篇 |
2004年 | 107946篇 |
2003年 | 101509篇 |
2002年 | 96344篇 |
2001年 | 93286篇 |
2000年 | 93792篇 |
1999年 | 77210篇 |
1998年 | 37322篇 |
1997年 | 34221篇 |
1996年 | 32382篇 |
1995年 | 31497篇 |
1994年 | 30341篇 |
1993年 | 28964篇 |
1992年 | 61708篇 |
1991年 | 59406篇 |
1990年 | 57509篇 |
1989年 | 56096篇 |
1988年 | 52498篇 |
1987年 | 49780篇 |
1986年 | 46784篇 |
1985年 | 48125篇 |
1984年 | 41490篇 |
1983年 | 36078篇 |
1982年 | 29795篇 |
1981年 | 27124篇 |
1980年 | 25044篇 |
1979年 | 38346篇 |
1978年 | 30738篇 |
1977年 | 28181篇 |
1976年 | 26328篇 |
1975年 | 28567篇 |
1974年 | 30895篇 |
1973年 | 30095篇 |
1972年 | 26039篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
11.
12.
13.
14.
Julia Nonnenmann Renate Stirner Julia Roider Maria C. Jung Kathrin Schr?dl Johannes R. Bogner Rika Draenert 《Journal of virology》2014,88(13):7678-7682
Myeloid-derived suppressor cells (MDSC) are immature myeloid cells with immunosuppressive function. Compared to the level in healthy controls (HC), no elevation of MDSC in chronic hepatitis C (cHEP-C) patients was found, and there was no difference in MDSC based on genotype or viral load (P > 0.25). Moreover, MDSC of cHEP-C patients inhibited CD8 T cell function as efficiently as MDSC of HC did. Since we detected neither quantitative nor qualitative differences in MDSC of cHEP-C patients relative to those of HC, we postulate that MDSC in peripheral blood are most likely not significant regarding immune dysfunction in cHEP-C. 相似文献
15.
16.
17.
18.
Bong Jin Kim Kyung Seob Song Hyun-Hee Kong Hee-Jae Cha Meesun Ock 《The Korean journal of parasitology》2014,52(1):85-87
We encountered a patient with heavy Hymenolepis nana infection. The patient was a 44-year-old Korean man who had suffered from chronic hepatitis (type B) for 15 years. A large number of H. nana adult worms were found during colonoscopy that was performed as a part of routine health screening. The parasites were scattered throughout the colon, as well as in the terminal ileum, although the patient was immunocompetent. Based on this study, colonoscopy may be helpful for diagnosis of asymptomatic H. nana infections. 相似文献
19.
An insufficiently known bivalve and gastropod assemblage from the Early-Middle Miocene (Tarkhanian-Chokrakian) of northern Sinop Province (Turkey), is analyzed. Environments of the assemblage are reconstructed for the Chokrakian as subtidal, with prevailing lime and sandy bottom and good aeration, and partially well vegetated. Impoverishment of the mollusk biocoenose in this part of the marine basin (only 18 bivalve and 22 gastropod species recorded) compared to other areas, including the closest regions, Bulgaria on the west and Georgia on the east, is emphasized. The relatively low diversity of the fauna is probably connected not only with insufficient collecting, but with special hydrological conditions. A special aspect of the fauna is highlighted by the presence of the bivalve Circomphalus foliaceolamellosus subplicatus (Orb.), which is rare in the Chokrakian. 相似文献
20.