全文获取类型
收费全文 | 6497篇 |
免费 | 724篇 |
国内免费 | 1462篇 |
专业分类
8683篇 |
出版年
2024年 | 34篇 |
2023年 | 133篇 |
2022年 | 306篇 |
2021年 | 372篇 |
2020年 | 301篇 |
2019年 | 327篇 |
2018年 | 273篇 |
2017年 | 236篇 |
2016年 | 291篇 |
2015年 | 429篇 |
2014年 | 513篇 |
2013年 | 543篇 |
2012年 | 665篇 |
2011年 | 562篇 |
2010年 | 418篇 |
2009年 | 414篇 |
2008年 | 443篇 |
2007年 | 399篇 |
2006年 | 341篇 |
2005年 | 322篇 |
2004年 | 268篇 |
2003年 | 258篇 |
2002年 | 196篇 |
2001年 | 121篇 |
2000年 | 98篇 |
1999年 | 84篇 |
1998年 | 93篇 |
1997年 | 56篇 |
1996年 | 35篇 |
1995年 | 27篇 |
1994年 | 26篇 |
1993年 | 15篇 |
1992年 | 20篇 |
1991年 | 14篇 |
1990年 | 8篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1973年 | 1篇 |
1967年 | 1篇 |
1955年 | 2篇 |
1950年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有8683条查询结果,搜索用时 0 毫秒
11.
Three-dimensional quantitative structure–activity relationship (3D-QSAR) studies were performed on a series of substituted 1,4-dihydroindeno[1,2-c]pyrazoles inhibitors, using molecular docking and comparative molecular field analysis (CoMFA). The docking results from GOLD 3.0.1 provide a reliable conformational alignment scheme for the 3D-QSAR model. Based on the docking conformations and alignments, highly predictive CoMFA model was built with cross-validated q 2 value of 0.534 and non-cross-validated partial least-squares analysis with the optimum components of six showed a conventional r 2 value of 0.911. The predictive ability of this model was validated by the testing set with a conventional r 2 value of 0.812. Based on the docking and CoMFA, we have identified some key features of the 1,4-dihydroindeno[1,2-c]pyrazoles derivatives that are responsible for checkpoint kinase 1 inhibitory activity. The analyses may be used to design more potent 1,4-dihydroindeno[1,2-c]pyrazoles derivatives and predict their activity prior to synthesis. 相似文献
12.
13.
Rong‐rong Zhu Qian Chen Zhi‐bo Liu Han‐guang Ruan Qi‐cai Wu Xue‐liang Zhou 《Journal of cellular and molecular medicine》2020,24(14):7907-7914
Increased expression and activity of cardiac and circulating cathepsin D and soluble fms‐like tyrosine kinase‐1 (sFlt‐1) have been demonstrated to induce and promote peripartum cardiomyopathy (PPCM) via promoting cleavage of 23‐kD prolactin (PRL) to 16‐kD PRL and neutralizing vascular endothelial growth factor (VEGF), respectively. We hypothesized that activation of Hes1 is proposed to suppress cathepsin D via activating Stat3, leading to alleviated development of PPCM. In the present study, we aimed to investigate the role of Notch1/Hes1 pathway in PPCM. Pregnant mice between prenatal 3 days and postpartum 3 weeks were fed with LY‐411575 (a notch inhibitor, 10 mg/kg/d). Ventricular function and pathology were evaluated by echocardiography and histological analysis. Western blotting analysis was used to examine the expression at the protein level. The results found that inhibition of Notch1 significantly promoted postpartum ventricular dilatation, myocardial hypertrophy and myocardial interstitial fibrosis and suppressed myocardial angiogenesis. Western blotting analysis showed that inhibition of Notch1 markedly increased cathepsin D and sFlt‐1, reduced Hes1, phosphorylated Stat3 (p‐Stat3), VEGFA and PDGFB, and promoted cleavage of 23k‐D PRL to 16‐kD PRL. Collectively, inhibition of Notch1/Hes1 pathway induced and promoted PPCM via increasing the expressions of cathepsin D and sFlt‐1. Notch1/Hes1 was a promising target for prevention and therapeutic regimen of PPCM. 相似文献
14.
Rui Zhou Huiying Sun Siting Zheng Jingwen Zhang Dongqiang Zeng Jianhua Wu Zhenhua Huang Xiaoxiang Rong Jianping Bin Yulin Liao Min Shi Wangjun Liao 《Journal of cellular and molecular medicine》2020,24(5):3229-3241
The heterogeneity in prognoses and chemotherapeutic responses of colon cancer patients with similar clinical features emphasized the necessity for new biomarkers that help to improve the survival prediction and tailor therapies more rationally and precisely. In the present study, we established a s troma-related l ncRNA s ignature (SLS) based on 52 lncRNAs to comprehensively predict clinical outcome. The SLS model could not only distinguish patients with different recurrence and mortality risks through univariate analysis, but also served as an independent factor for relapse-free and overall survival. Compared with the conventionally used TNM stage system, the SLS model clearly possessed higher predictive accuracy. Moreover, the SLS model also effectively screened chemotherapy-responsive patients, as only patients in the low-SLS group could benefit from adjuvant chemotherapy. The following cell infiltration and competing endogenous RNA (ceRNA) network functional analyses further confirmed the association between the SLS model and stromal activation-related biological processes. Additionally, this study also identified three phenotypically distinct colon cancer subtypes that varied in clinical outcome and chemotherapy benefits. In conclusion, our SLS model may be a significant determinant of survival and chemotherapeutic decision-making in colon cancer and may have a strong clinical transformation value. 相似文献
15.
16.
Rong Yu Shiyu Wen Qiaona Wang Congying Wang Liping Zhang Xingxin Wu Jianmei Li Lingdong Kong 《Journal of neurochemistry》2021,157(6):1979-1991
17.
Hydrobiologia - UV-B radiation is an increasing threat to aquatic organisms and also a potential driving force for zooplankton population dynamics. To explore the ecological effects of UVR on... 相似文献
18.
β-Carboline-Based pH Fluorescent Probe and Its Application for Monitoring Enzymatic Ester Hydrolysis
A novel pH-activatable fluorescent probe, 1-(propan-2-yl)-9H-pyrido[3,4-b]indole-3-carboxylic acid ( L-1 ), based on β-carboline derivatives, has been developed, which displays significant fluorescent response toward pH variation with high selectivity, good photo-stability and favorable pKa value. Moreover, L-1 can dynamically monitor the release of protons during ester hydrolysis reaction in consistent with enzymatic kinetics manner. 相似文献
19.
Yang Liu Gaofeng Liu Zhiwen Li Wei Rong Jianping Yu Ying Zhou 《Nucleosides, nucleotides & nucleic acids》2013,32(10):645-655
T-Hg-T base pair formation has been demonstrated to be compatible with duplex DNA context, with considerable thermal stability contribution. Here, the T-Hg-T stem in two small DNAzymes 8–17 and 10–23 was studied for its structural and functional roles. The recognition arm 5′ to the cleavage site of 10–23 DNAzyme complex and the stem in the catalytic loop of 8–17 DNAzyme could be replaced by consecutive T-Hg-T stem of different length. The linear relationship between the activity of the complex 10–23DZ-6T+D19–6T and the concentration of Hg2+ demonstrated that the T-Hg-T stem contributes thermal stability of the recognition arm binding. The effect of T-Hg-T stem in the catalytic core of 8–17 DNAzyme and the position-dependent effect in 10–23 DNAzyme demonstrated that T-Hg-T base pair is not compatible with canonical base pairs in playing the functions of nucleic acids. 相似文献
20.
Guang-qiao Zeng Rong Liu Hai-xing Liao Xin-feng Zhang Yuan-xin Qian Bao-hua Liu Qing-hong Wu Jin Zhao Wei-wang Gu Hong-tao Li 《PloS one》2013,8(11)