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   16621篇
  免费   1463篇
  国内免费   19篇
耳鼻咽喉   120篇
儿科学   633篇
妇产科学   457篇
基础医学   2153篇
口腔科学   179篇
临床医学   2445篇
内科学   2764篇
皮肤病学   271篇
神经病学   1560篇
特种医学   475篇
外科学   1913篇
综合类   274篇
一般理论   16篇
预防医学   2303篇
眼科学   226篇
药学   1003篇
中国医学   18篇
肿瘤学   1293篇
  2023年   116篇
  2022年   84篇
  2021年   281篇
  2020年   180篇
  2019年   348篇
  2018年   346篇
  2017年   274篇
  2016年   274篇
  2015年   335篇
  2014年   493篇
  2013年   727篇
  2012年   1034篇
  2011年   1120篇
  2010年   611篇
  2009年   517篇
  2008年   971篇
  2007年   1018篇
  2006年   968篇
  2005年   946篇
  2004年   889篇
  2003年   842篇
  2002年   846篇
  2001年   362篇
  2000年   342篇
  1999年   301篇
  1998年   219篇
  1997年   150篇
  1996年   150篇
  1995年   144篇
  1994年   123篇
  1993年   130篇
  1992年   218篇
  1991年   224篇
  1990年   205篇
  1989年   197篇
  1988年   170篇
  1987年   184篇
  1986年   175篇
  1985年   182篇
  1984年   140篇
  1983年   101篇
  1982年   68篇
  1981年   65篇
  1980年   68篇
  1979年   80篇
  1978年   65篇
  1977年   68篇
  1975年   66篇
  1974年   65篇
  1973年   69篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Patient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty-four reviews were quantitative or mixed-methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost-effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost-effectiveness of navigation in screening programs.  相似文献   
3.
4.
5.
6.
7.
8.
9.
Group A Streptococcus (GAS) predominantly exists as a colonizer of the human oropharynx that occasionally breaches epithelial barriers to cause invasive diseases. Despite the frequency of GAS carriage, few investigations into the contributory molecular mechanisms exist. To this end, we identified a naturally occurring polymorphism in the gene encoding the streptococcal collagen-like protein A (SclA) in GAS carrier strains. All previously sequenced invasive serotype M3 GAS possess a premature stop codon in the sclA gene truncating the protein. The carrier polymorphism is predicted to restore SclA function and was infrequently identified by targeted DNA sequencing in invasive strains of the same serotype. We demonstrate that a strain with the carrier sclA allele expressed a full-length SclA protein, while the strain with the invasive sclA allele expressed a truncated variant. An isoallelic mutant invasive strain with the carrier sclA allele exhibited decreased virulence in a mouse model of invasive disease and decreased multiplication in human blood. Further, the isoallelic invasive strain with the carrier sclA allele persisted in the mouse nasopharynx and had increased adherence to cultured epithelial cells. Repair of the premature stop codon in the invasive sclA allele restored the ability to bind the extracellular matrix proteins laminin and cellular fibronectin. These data demonstrate that a mutation in GAS carrier strains increases adherence and decreases virulence and suggest selection against increased adherence in GAS invasive isolates.  相似文献   
10.
2‐deoxy D‐glucose (2DG) was tested for efficacy in treating alopecia areata using the C3H/HeJ skin graft model. 2DG has proven to be efficacious in treatment of various mouse models of autoimmunity with minimal serious side effects noted. This agent has been shown to normalize abnormally activated T‐cell populations while also preventing cell surface expression of NKG2D; key factors defining alopecia areata disease progression. Daily oral ingestion of 2DG via drinking water to mice with patchy or diffuse alopecia areata for 16 weeks failed to prevent expansion of alopecia or cause regrowth of hair in treated mice. Histologically, there were no differences between treated and control groups. These results indicate that, while 2DG is effective for some autoimmune diseases, it was not efficacious for the cell‐mediated autoimmune mouse disease, alopecia areata.  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