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   5942篇
  免费   504篇
  国内免费   16篇
耳鼻咽喉   55篇
儿科学   182篇
妇产科学   145篇
基础医学   843篇
口腔科学   100篇
临床医学   598篇
内科学   1072篇
皮肤病学   102篇
神经病学   561篇
特种医学   249篇
外科学   1036篇
综合类   105篇
一般理论   4篇
预防医学   527篇
眼科学   58篇
药学   321篇
中国医学   5篇
肿瘤学   499篇
  2023年   32篇
  2022年   30篇
  2021年   132篇
  2020年   86篇
  2019年   148篇
  2018年   166篇
  2017年   109篇
  2016年   138篇
  2015年   147篇
  2014年   191篇
  2013年   284篇
  2012年   410篇
  2011年   401篇
  2010年   207篇
  2009年   204篇
  2008年   322篇
  2007年   355篇
  2006年   274篇
  2005年   256篇
  2004年   256篇
  2003年   218篇
  2002年   220篇
  2001年   143篇
  2000年   140篇
  1999年   131篇
  1998年   53篇
  1997年   60篇
  1996年   44篇
  1995年   53篇
  1994年   38篇
  1993年   31篇
  1992年   101篇
  1991年   88篇
  1990年   111篇
  1989年   93篇
  1988年   74篇
  1987年   76篇
  1986年   81篇
  1985年   63篇
  1984年   53篇
  1983年   41篇
  1982年   31篇
  1981年   28篇
  1979年   40篇
  1978年   29篇
  1977年   21篇
  1976年   22篇
  1975年   22篇
  1974年   30篇
  1972年   21篇
排序方式: 共有6462条查询结果,搜索用时 46 毫秒
1.
2.
Globally, the COVID‐19 pandemic has already led to major increases in unemployment and is expected to lead to unprecedented increases in poverty and food and nutrition insecurity, as well as poor health outcomes. Families where young children, youth, pregnant and lactating women live need to be protected against the ongoing protracted pandemic and the aftershocks that are very likely to follow for years to come. The future wellbeing of the vast majority of the world now depends on reconfiguring the current ineffective food, nutrition, health, and social protection systems to ensure food and nutrition security for all. Because food, nutrition, health, and socio‐economic outcomes are intimately inter‐linked, it is essential that we find out how to effectively address the need to reconfigure and to provide better intersecoral coordination among global and local food, health care, and social protection systems taking equity and sutainability principles into account. Implementation science research informed by complex adaptive sytems frameworks will be needed to fill in the major knowledge gaps. Not doing so will not only put the development of individuals at further risk, but also negatively impact on the development potential of entire nations and ultimately our planet.  相似文献   
3.
4.
PURPOSE: To delineate gene expression patterns and profile changes in metastatic tumor biopsies at baseline and 1 month after treatment with the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib in patients with metastatic breast cancer. EXPERIMENTAL DESIGN: Patients were treated with 150 mg of oral erlotinib daily. Gene expression profiles were measured with Affymetrix U133A GeneChip and immunohistochemistry was used to validate microarray findings. RESULTS: Estrogen receptor (ER) status by immunohistochemistry is nearly coincided with the two major expression clusters determined by expression of genes using unsupervised hierarchical clustering analysis. One of 10 patients had an EGFR-positive tumor detected by both microarray and immunohistochemistry. In this tumor, tissue inhibitor of metalloproteinases-3 and collagen type 1 alpha 2, which are the EGF-down-regulated growth repressors, were significantly increased by erlotinib. Gene changes in EGFR-negative tumors are those of G-protein-linked and cell surface receptor-linked signaling. Gene ontology comparison analysis pretreatment and posttreatment in EGFR-negative tumors revealed biological process categories that have more genes differentially expressed than expected by chance. Among 495 gene ontology categories, the significant differed gene ontology groups include G-protein-coupled receptor protein signaling (34 genes, P = 0.002) and cell surface receptor-linked signal transduction (74 genes, P = 0.007). CONCLUSIONS: ER status reflects the major difference in gene expression pattern in metastatic breast cancer. Erlotinib had effects on genes of EGFR signaling pathway in the EGFR-positive tumor and on gene ontology biological process categories or genes that have function in signal transduction in EGFR-negative tumors.  相似文献   
5.
6.
7.
The aim of the study was to describe the experience, current trends and management of incontinence surgery for urodynamic stress incontinence (USI) in the United Kingdom. The study was a postal questionnaire survey that was sent to a cohort of surgeons known to be performing continence surgery. The subjects addressed included the considered role of the surgeon, the total number and type of operations performed in the last year, urodynamics and physiotherapy prior to incontinence surgery, operative complications, postoperative advice and follow-up (lengths and methods). The response rate was 54%. Large variations were found in all areas. The survey provides evidence of the number of incontinence operations performed, potentially important trends and differences in the practice and management of incontinence in the United Kingdom. This survey may be helpful in making guidelines and standards for audit at regional, local and individual levels as well as recommendations for strategies to enhance professional expertise in urogynaecology in the United Kingdom.  相似文献   
8.
9.

Background  

Colorectal cancer, if detected early, has greater than 90% 5-year survival. However, survival has been shown to vary across racial/ethnic groups in the United States, despite the availability of early detection methods.  相似文献   
10.
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