全文获取类型
收费全文 | 4113篇 |
免费 | 435篇 |
国内免费 | 499篇 |
出版年
2024年 | 6篇 |
2023年 | 62篇 |
2022年 | 96篇 |
2021年 | 276篇 |
2020年 | 226篇 |
2019年 | 268篇 |
2018年 | 182篇 |
2017年 | 158篇 |
2016年 | 216篇 |
2015年 | 321篇 |
2014年 | 320篇 |
2013年 | 347篇 |
2012年 | 391篇 |
2011年 | 364篇 |
2010年 | 213篇 |
2009年 | 197篇 |
2008年 | 223篇 |
2007年 | 156篇 |
2006年 | 162篇 |
2005年 | 128篇 |
2004年 | 116篇 |
2003年 | 103篇 |
2002年 | 102篇 |
2001年 | 83篇 |
2000年 | 58篇 |
1999年 | 45篇 |
1998年 | 32篇 |
1997年 | 25篇 |
1996年 | 25篇 |
1995年 | 19篇 |
1994年 | 16篇 |
1993年 | 15篇 |
1992年 | 21篇 |
1991年 | 11篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有5047条查询结果,搜索用时 15 毫秒
991.
992.
993.
Wei Li Chuan Wei Lei Xu Beibei Yu Ying Chen Di Lu Lina Zhang Xian Song Liyang Dong Sha Zhou Zhipeng Xu Jifeng Zhu Xiaojun Chen Chuan Su 《PLoS pathogens》2021,17(3)
Infection with schistosome results in immunological changes that might influence the skeletal system by inducing immunological states affecting bone metabolism. We investigated the relationships between chronic schistosome infection and bone metabolism by using a mouse model of chronic schistosomiasis, affecting millions of humans worldwide. Results showed that schistosome infection resulted in aberrant osteoclast-mediated bone loss, which was accompanied with an increased level of receptor activator of nuclear factor-κB (NF-κB) Ligand (RANKL) and decreased level of osteoprotegerin (OPG). The blockade of RANKL by the anti-RANKL antibody could prevent bone loss in the context of schistosome infection. Meanwhile, both B cells and CD4+ T cells, particularly follicular helper T (Tfh) cell subset, were the important cellular sources of RANKL during schistosome infection. These results highlight the risk of bone loss in schistosome-infected patients and the potential benefit of coupling bone therapy with anti-schistosome treatment. 相似文献
994.
995.
ManH, a novel substrate-binding protein of an ABC transporter, was identified from the mannan utilization gene cluster of Bacillus sp. N16-5. We cloned, overexpressed, and purified ManH and measured its binding affinity to different substrates by isothermal titration calorimetry. ManH binds to mannotriose, mannotetraose, mannopentose, and galactosyl-mannotriose with dissociation constants in the micromolar range. Deletion of manH led to decreased growth ability of the strain when cultivated in medium with manno-oligosaccharides or mannan as the carbon source. ManH belongs to a manno-oligosaccharide transporter and plays an important role in mannan utilization by Bacillus sp. N16-5. 相似文献
996.
997.
Min He Ying Han Changjing Cai Ping Liu Yihong Chen Hong Shen Xingyuan Xu Shan Zeng 《Journal of cellular and molecular medicine》2021,25(7):3391-3399
CLEC10A, (C-type lectin domain family 10, member A), as the member of C-type lectin receptors (CLRs), plays a vital role in modulating innate immunity and adaptive immunity and has shown great potential as an immunotherapy target for cancers. However, there is no functional research of CLEC10A in prognostic risk, immunotherapy or any other treatment of lung adenocarcinoma (LUAD). We performed bioinformatics analysis on LUAD data downloaded from TCGA (The Cancer Genome Atlas) and GEO (Gene Expression Omnibus), and jointly analysed with online databases such as HPA, LinkedOmics, TIMER, ESTIMATE and TISIDB. We found that lower expression of CLEC10A was accompanied with worse outcomes of LUAD patients. Moreover, CLEC10A expression was significantly correlated with a variety of the tumour-infiltrating immune cells (TIICs). As a promising prognosis predictor and potential immunotherapy target, the potential influence and mechanisms of CLEC10A in LUAD deserve further exploring. 相似文献
998.
999.
1000.
Biological characterization of a simian immunodeficiency virus-like retrovirus (HTLV-IV): evidence for CD4-associated molecules required for infection 总被引:24,自引:19,他引:5 下载免费PDF全文
J A Hoxie B S Haggarty S E Bonser J L Rackowski H Shan P J Kanki 《Journal of virology》1988,62(8):2557-2568
We have analyzed a number of biological features of HTLV-IV, a retrovirus indistinguishable from a macaque isolate of simian immunodeficiency virus (SIV), and compared this virus with several strains of human immunodeficiency virus type 1 (HIV-1). Although HTLV-IV was found to be similar to HIV-1 in its tropism for CD4+ lymphocytes, its effects on CD4 expression and the ability of its externalized envelope molecule to form a complex directly with the CD4 molecule, a number of striking differences were noted. Unlike with HIV-1, the range of cells susceptible to HTLV-IV infection and syncytia formation was restricted to a subset of CD4+ cell lines, particularly those that coexpressed CD4 with human leukocyte antigen (HLA) class II antigens. An analysis of the patterns of HTLV-IV infection with B x T somatic cell hybrids indicated that for this virus, molecules in addition to CD4 were probably required to facilitate infection and cell fusion. Additional studies of HTLV-IV infection of Sup-T1 cells, which are exquisitely sensitive to cytopathic effects induced by HIV-1, demonstrated that HTLV-IV infection could occur in the absence of cytopathic effects and, remarkably, with minimal or no downmodulation of the CD4 molecule from the cell surface. The failure of HTLV-IV infection to reduce the expression of several CD4 epitopes suggested that the HTLV-IV envelope produced by Sup-T1 cells was altered in its ability to interact with or bind to CD4. Additional differences were also noted in the size of the transmembrane envelope molecule of HTLV-IV produced by Sup-T1 cells, indicating that cell-specific alterations in processing of the HTLV-IV envelope occurred during the production of virus in this cell line. Understanding the basis for these biological differences between HTLV-IV and the HIV-1 viruses may help to elucidate more general mechanisms for pathogenesis of other members of the SIV and HIV families of retroviruses. 相似文献