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   110569篇
  免费   8663篇
  国内免费   391篇
耳鼻咽喉   1182篇
儿科学   2810篇
妇产科学   1833篇
基础医学   15608篇
口腔科学   2326篇
临床医学   11379篇
内科学   23470篇
皮肤病学   1859篇
神经病学   11631篇
特种医学   4500篇
外国民族医学   11篇
外科学   15755篇
综合类   1507篇
现状与发展   1篇
一般理论   88篇
预防医学   8915篇
眼科学   1939篇
药学   7698篇
中国医学   113篇
肿瘤学   6998篇
  2023年   560篇
  2022年   972篇
  2021年   2273篇
  2020年   1401篇
  2019年   2124篇
  2018年   2580篇
  2017年   1911篇
  2016年   2274篇
  2015年   2627篇
  2014年   3482篇
  2013年   4583篇
  2012年   7085篇
  2011年   7164篇
  2010年   4182篇
  2009年   3818篇
  2008年   6354篇
  2007年   6883篇
  2006年   6368篇
  2005年   6336篇
  2004年   5932篇
  2003年   5265篇
  2002年   5229篇
  2001年   2136篇
  2000年   2056篇
  1999年   1871篇
  1998年   1314篇
  1997年   1109篇
  1996年   899篇
  1995年   874篇
  1994年   766篇
  1993年   704篇
  1992年   1323篇
  1991年   1230篇
  1990年   1161篇
  1989年   1101篇
  1988年   980篇
  1987年   940篇
  1986年   935篇
  1985年   939篇
  1984年   754篇
  1983年   669篇
  1982年   627篇
  1981年   512篇
  1980年   458篇
  1979年   629篇
  1978年   476篇
  1977年   435篇
  1975年   374篇
  1974年   419篇
  1973年   405篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
International Journal of Clinical Oncology - Immune-checkpoint inhibitors (ICIs) are standard treatments for metastatic non-small cell lung cancer (NSCLC). Patients with poor performance status...  相似文献   
4.
5.
The current study explored the influence of three methods of parental emotion discourse (structured story-telling, reminiscing, and picture book) and their relation to preschoolers’ emotion understanding. Thirty-seven families participated in the study. Analyses showed that the structured story-telling method produced more emotion words, was high in unique emotion words, and was high for both emotion labelling and explanations. All three methods showed some potential to predict preschooler’s emotion understanding. Structured story-telling was best at predicting role-taking, while reminiscing and the picture book both were better at predicting situation knowledge. Additional studies are needed to further explore the influence of different methods of assessing emotion discourse to enhance validity and reliability of research in this field.  相似文献   
6.
7.
8.
Coxiella burnetii is an obligate intracellular Gram-negative bacterium that causes the zoonotic disease Q fever. Although Q fever is mainly transmitted by aerosol infection, study of the immune responses in the lung following pulmonary C. burnetii infection is lacking. Neutrophils are considered the first immune cell to migrate into the lung and play an important role in host defense against aerosol infection with microbial pathogens. However, the role of neutrophils in the host defense against C. burnetii infection remains unclear. To determine the role of neutrophils in protective immunity against C. burnetii infection, the RB6-8C5 antibody was used to deplete neutrophils in mice before intranasal infection with C. burnetii. The results indicated that neutrophil-depleted mice developed more severe disease than their wild-type counterparts, suggesting that neutrophils play an important role in host defense against C. burnetii pulmonary infection. We also found that neither CXC chemokine receptor 2 (CXCR2) nor interleukin-17 (IL-17) receptor (IL-17R) deficiency changed the severity of disease following intranasal C. burnetii challenge, suggesting that keratinocyte-derived chemokine and IL-17 may not play essential roles in the response to C. burnetii infection. However, significantly higher C. burnetii genome copy numbers were detected in the lungs of IL-1R−/− mice at 14 days postinfection. This indicates that IL-1 may be important for the clearance of C. burnetii from the lungs following intranasal infection. Our results also suggest that neutrophils are involved in protecting vaccinated mice from C. burnetii challenge-induced disease. This is the first study to demonstrate an important role for neutrophils in protective immunity against C. burnetii infection.  相似文献   
9.
10.
Nidogen 1 (NID1) is a glycoprotein found in basement membranes involved in cross-linking collagen IV and laminin. The role of NID in breast cancer has only been evaluated in a small number of studies and the findings of these studies have been inconsistent. Our previous work revealed that highly tumorigenic murine mammary tumor cells express high levels of Nid1 while weakly tumorigenic mammary tumor cells express low levels of Nid1. To investigate Nid1, two stable knockdown lines were created, and Nid1 knockdown was confirmed at both the mRNA and protein level. Nid1 knockdown significantly reduced cell proliferation and migration/invasion and these reductions in proliferation and migration/invasion could be rescued by conditioned media containing NID1 protein. The reduced migration/invasion observed in the Nid1 knockdown cells was not associated with significant alterations in the epithelial gene Cdh1 or the mesenchymal genes Snai1, Snai2, Twist1, Twist2, Zeb1 and Zeb2. Therefore, suppression of Nid1 expression reduces proliferation and migration/invasion in claudin-low murine mammary tumor cells.  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