首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7808篇
  免费   671篇
  国内免费   909篇
  9388篇
  2024年   41篇
  2023年   166篇
  2022年   358篇
  2021年   552篇
  2020年   395篇
  2019年   467篇
  2018年   413篇
  2017年   332篇
  2016年   381篇
  2015年   563篇
  2014年   666篇
  2013年   626篇
  2012年   788篇
  2011年   642篇
  2010年   422篇
  2009年   338篇
  2008年   334篇
  2007年   312篇
  2006年   241篇
  2005年   217篇
  2004年   148篇
  2003年   112篇
  2002年   136篇
  2001年   104篇
  2000年   75篇
  1999年   79篇
  1998年   72篇
  1997年   52篇
  1996年   45篇
  1995年   36篇
  1994年   47篇
  1993年   25篇
  1992年   22篇
  1991年   25篇
  1990年   25篇
  1989年   26篇
  1988年   17篇
  1987年   20篇
  1986年   17篇
  1985年   11篇
  1984年   7篇
  1983年   6篇
  1982年   4篇
  1981年   3篇
  1980年   3篇
  1979年   3篇
  1973年   2篇
  1970年   2篇
  1968年   2篇
  1953年   1篇
排序方式: 共有9388条查询结果,搜索用时 18 毫秒
71.
72.
Salt stress is one important factor influencing the growth and development of plants, and salt tolerance of plants is a result of combined action of multiple genes and mechanisms. Rosa rugosa is not only an important ornamental plant, but also the natural aromatic plant of high value. Wild R. rugosa which is naturally distributed on the coast and islands of China has a good salt tolerance due to the special living environment. Here, the vacuolar Na+/H+ reverse transporter gene (NHX1) and the vacuolar H+-ATPase subunit C gene (VHA-c) closely related to plant salt tolerance were isolated from wild R. rugosa, and the expression patterns in R. rugosa leaves of the two genes under NaCl stress were determined by real-time quantitative fluorescence PCR. The results showed that the RrNHX1 protein is a constitutive Na+/H+ reverse transporter, the expression of the RrNHX1 gene first increased and then decreased with the increasing salt concentration, and had a time-controlled effect. The RrVHA-c gene is suggestive of the housekeeping feature, its expression pattern showed a similar variation trend with the RrNHX1 gene under the stress of different concentrations of NaCl, and its temporal expression level under 200 mM NaCl stress presented bimodal change. These findings indicated that RrNHX1 and RrVHA-c genes are closely associated with the salt tolerance trait of wild R. rugosa.  相似文献   
73.
Ribosomal protein L34 (RPL34), belonging to the L34E family of ribosomal proteins, was reported to be dysregulated in several types of cancers and plays important roles in tumor progression. However, the expression and roles of RPL34 in human glioma remain largely unknown. Thus, the objective of this study was to investigate the expression and role of RPL34 in glioma. We report here that RPL34 is highly expressed in human glioma tissues and cell lines. Knockdown of RPL34 markedly inhibited the proliferation, migration, and invasion, as well as prevented the epithelial-mesenchymal transition phenotype in glioma cells. Further, mechanistic analysis showed that knockdown of RPL34 significantly downregulated the levels of p-JAK and p-STAT3 in glioma cells. Taken together, our findings indicated that knockdown of RPL34 inhibits the proliferation and migration of glioma cells through the inactivation of JAK/STAT3 signaling pathway. Thus, RPL34 may serve as a potential therapeutic target for the treatment of glioma.  相似文献   
74.
Chronic prostatitis is a common urological disease. The etiology of this disease and effective therapy for its treatment are yet to be elucidated. We investigated the functions of XLQ® in chronic nonbacterial prostatitis using a complete Freund's adjuvant-induced rat model. Prostates and blood samples were collected for further evaluation after oral gavage with XLQ ® or a vehicle for 4 weeks. The results showed that XLQ ® significantly decreased the prostate index, ameliorated the histopathologic changes, and reduced CD3+ and CD45+ cell infiltration in the prostate stroma. Further study showed that XLQ ® suppressed the expression of proinflammatory cytokines, such as interleukin (IL)-1β, IL-2, IL-6, IL-17A, monocyte chemoattractant protein-1, and tumor necrosis factor-α. XLQ ® showed a strong antioxidant capacity by enhancing the activities of antioxidative enzymes (e.g., total superoxide dismutase, catalase, and glutathione peroxidase) and decreasing the level of lipid peroxidation products (malondialdehyde). Moreover, XLQ ® can suppress the activation of nuclear factor-κB and P38-mitogen-activated protein kinase signaling pathways. In summary, XLQ ® has affirmative effects on chronic prostatitis, which could be attributed to its anti-inflammatory and antioxidative capacities. On the basis of these results, XLQ ® can be developed as an effective and safe therapy for chronic prostatitis.  相似文献   
75.
76.
77.
The Epic® system, a high-throughput label-free optical biosensor system, is applied for the biochemical interrogation of phosphor-specific interactions of the 14-3-3 protein and its substrates. It has shown the capability not only for high-throughput characterization of binding rank and affinity but also for the exploration of potential interacting kinases for the substrates. A perspective of biochemical applications for diagnostics and biomarker discovery, as well as cell-based applications for endogenous receptors and viral infection characterization, are also provided.  相似文献   
78.
The introduction of next generation sequencing methods in genome studies has made it possible to shift research from a gene-centric approach to a genome wide view. Although methods and tools to detect single nucleotide polymorphisms are becoming more mature, methods to identify and visualize structural variation (SV) are still in their infancy. Most genome browsers can only compare a given sequence to a reference genome; therefore, direct comparison of multiple individuals still remains a challenge. Therefore, the implementation of efficient approaches to explore and visualize SVs and directly compare two or more individuals is desirable. In this article, we present a visualization approach that uses space-filling Hilbert curves to explore SVs based on both read-depth and pair-end information. An interactive open-source Java application, called Meander, implements the proposed methodology, and its functionality is demonstrated using two cases. With Meander, users can explore variations at different levels of resolution and simultaneously compare up to four different individuals against a common reference. The application was developed using Java version 1.6 and Processing.org and can be run on any platform. It can be found at http://homes.esat.kuleuven.be/~bioiuser/meander.  相似文献   
79.
Ren F  Li BC  Zhang NN  Cao M  Dan WB  Zhang SQ 《Biotechnology letters》2008,30(6):1075-1080
B-Cell activating factor (BAFF) is critical for B cell survival and maturation; excessive expression of it corrupts B-cell tolerance and may lead to autoimmunity. The gene, scFv-Fc, coding for the antibody of BAFF was inserted into the eukaryotic expression vector, pPICZαA, and transformed into Pichia pastoris. A high-level expression strain was obtained using a ‘yeastern blotting’ method. The scFv-Fc antibody was purified and 56 mg was obtained from 1 l of culture supernatant. It retained high binding activity to both soluble BAFF and membrane-bound BAFF.  相似文献   
80.
Shen  He  Wu  Shuyu  Chen  Xi  Xu  Bai  Ma  Dezun  Zhao  Yannan  Zhuang  Yan  Chen  Bing  Hou  Xianglin  Li  Jiayin  Cao  Yudong  Fu  Xianyong  Tan  Jun  Yin  Wen  Li  Juan  Meng  Li  Shi  Ya  Xiao  Zhifeng  Jiang  Xingjun  Dai  Jianwu 《中国科学:生命科学英文版》2020,63(12):1879-1886
Science China Life Sciences - Spinal cord injury (SCI), especially complete transected SCI, leads to loss of cells and extracellular matrix and functional impairments. In a previous study, we...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号