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   2196篇
  免费   134篇
  国内免费   3篇
  2333篇
  2024年   2篇
  2023年   15篇
  2022年   39篇
  2021年   101篇
  2020年   32篇
  2019年   42篇
  2018年   79篇
  2017年   53篇
  2016年   84篇
  2015年   99篇
  2014年   148篇
  2013年   174篇
  2012年   206篇
  2011年   234篇
  2010年   131篇
  2009年   127篇
  2008年   140篇
  2007年   118篇
  2006年   106篇
  2005年   75篇
  2004年   84篇
  2003年   58篇
  2002年   58篇
  2001年   12篇
  2000年   14篇
  1999年   7篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1995年   8篇
  1994年   3篇
  1993年   7篇
  1992年   4篇
  1991年   3篇
  1990年   5篇
  1989年   3篇
  1988年   5篇
  1987年   6篇
  1986年   4篇
  1985年   9篇
  1983年   6篇
  1979年   4篇
  1978年   4篇
  1975年   1篇
  1974年   2篇
  1973年   2篇
  1970年   5篇
  1969年   2篇
  1967年   1篇
  1966年   1篇
排序方式: 共有2333条查询结果,搜索用时 15 毫秒
21.
In Vitro Cellular & Developmental Biology - Plant - An efficient in vitro propagation and synthetic seed production protocol was established for the conservation of Decalepis salicifolia (Bedd....  相似文献   
22.
Plant Cell, Tissue and Organ Culture (PCTOC) - A method for in vitro screening and selection of drought (moisture stress) tolerant mango calli was developed. Poly ethylene glycol (PEG) (Molecular...  相似文献   
23.
24.
25.
Singh  Gagandeep  Ahuja  Amit  Rao  Uma  Somvanshi  Vishal Singh 《BioControl》2021,66(5):701-712

Entomopathogenic nematodes (EPNs) of the genera Heterorhabditis and Steinernema kill insects with the help of their symbiotic bacteria. They are widely used as biocontrol agents to manage insect pests of crops. The infective juveniles (IJ) of EPNs are isolated from soil by insect baiting technique, which is labour-intensive, time-consuming, wasteful, and inefficient. Here, we present loop-mediated isothermal amplification (LAMP) assays for rapid detection of Heterorhabditis spp. (Het-LAMP) and Steinernema spp. (Ste-LAMP) from total soil DNA. The primers for Het-LAMP and Ste-LAMP were designed using ITS and 18S rDNA regions of genomic DNA. The LAMP reactions could be completed in 60 min, at 66 °C and 68 °C, respectively, followed by termination at 85 °C for 5 min. The assays were highly sensitive and could detect up to 0.02 picograms of Heterorhabditis DNA and 96 picograms of Steinernema DNA in a 25 μl reaction. Both the assays were specific for the target nematode species and detected the presence of a single IJ in the total DNA extracted from 250 mg of soil. The assays developed in this study would be of immense utility for the efficient detection and identification of native EPNs in large-scale surveys. These assays are amenable to automation and could be used to develop convenient detection kits for point-of-service diagnosis of EPNs in the field without the need for a trained and experienced personnel.

  相似文献   
26.
International Journal of Peptide Research and Therapeutics - Whipple’s disease is one of the rare maladies in terms of spread but very fatal one as it is linked with many disorders (like...  相似文献   
27.
28.
29.
Despite the important diagnostic value of evaluating antibody responses to individual human pathogens, antibody profiles against multiple infectious agents have not been used to explore health and disease mainly for technical reasons.  We hypothesized that the interplay between infection and chronic disease might be revealed by profiling antibodies against multiple agents. Here, the levels of antibodies against a panel of 13 common infectious agents were evaluated with the quantitative Luciferase Immunoprecipitation Systems (LIPS) in patients from three disease cohorts including those with pathogenic anti-interferon-γ autoantibodies (IFN-γ AAB), HIV and Sjögren’s syndrome (SjS) to determine if their antibody profiles differed from control subjects.  The IFN-γ AAB patients compared to controls demonstrated statistically higher levels of antibodies against VZV (p=0.0003), EBV (p=0.002), CMV (p=0.003), and C. albicans (p=0.03), but lower antibody levels against poliovirus (p=0.04). Comparison of HIV patients with blood donor controls revealed that the patients had higher levels of antibodies against CMV (p=0.0008), HSV-2 (p=0.0008), EBV (p=0.001), and C. albicans (p=0.01), but showed decreased levels of antibodies against coxsackievirus B4 (p=0.0008), poliovirus (p=0.0005),   and HHV-6B (p=0.002). Lastly, SjS patients had higher levels of anti-EBV antibodies (p=0.03), but lower antibody levels against several enteroviruses including a newly identified picornavirus, HCoSV-A (p=0.004), coxsackievirus B4 (p=0.04), and poliovirus (p=0.02). For the IFN-γ AAB and HIV cohorts, principal component analysis revealed unique antibody clusters that showed the potential to discriminate patients from controls.  The results suggest that antibody profiles against these and likely other common infectious agents may yield insight into the interplay between exposure to infectious agents, dysbiosis, adaptive immunity and disease activity.  相似文献   
30.
Earlier, we reported that CTLA4 expression is inversely correlated with CD38 expression in chronic lymphocytic leukemia (CLL) cells. However, the specific role of CTLA4 in CLL pathogenesis remains unknown. Therefore, to elucidate the possible role of CTLA4 in CLL pathogenesis, CTLA4 was down-regulated in primary CLL cells. We then evaluated proliferation/survival in these cells using MTT, 3H-thymidine uptake and Annexin-V apoptosis assays. We also measured expression levels of downstream molecules involved in B-cell proliferation/survival signaling including STAT1, NFATC2, c-Fos, c-Myc, and Bcl-2 using microarray, PCR, western blotting analyses, and a stromal cell culture system. CLL cells with CTLA4 down-regulation demonstrated a significant increase in proliferation and survival along with an increased expression of STAT1, STAT1 phosphorylation, NFATC2, c-Fos phosphorylation, c-Myc, Ki-67 and Bcl-2 molecules. In addition, compared to controls, the CTLA4-downregulated CLL cells showed a decreased frequency of apoptosis, which also correlated with increased expression of Bcl-2. Interestingly, CLL cells from lymph node and CLL cells co-cultured on stroma expressed lower levels of CTLA4 and higher levels of c-Fos, c-Myc, and Bcl-2 compared to CLL control cells. These results indicate that microenvironment-controlled-CTLA4 expression mediates proliferation/survival of CLL cells by regulating the expression/activation of STAT1, NFATC2, c-Fos, c-Myc, and/or Bcl-2.  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