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   197161篇
  免费   2682篇
  国内免费   77篇
耳鼻咽喉   1515篇
儿科学   7371篇
妇产科学   3352篇
基础医学   18721篇
口腔科学   2042篇
临床医学   14348篇
内科学   35523篇
皮肤病学   1200篇
神经病学   17572篇
特种医学   9951篇
外国民族医学   1篇
外科学   33070篇
综合类   2629篇
一般理论   15篇
预防医学   19113篇
眼科学   3532篇
药学   11352篇
中国医学   661篇
肿瘤学   17952篇
  2023年   223篇
  2022年   401篇
  2021年   986篇
  2020年   475篇
  2019年   824篇
  2018年   22727篇
  2017年   17886篇
  2016年   20030篇
  2015年   1540篇
  2014年   1765篇
  2013年   1888篇
  2012年   8585篇
  2011年   22547篇
  2010年   19560篇
  2009年   12237篇
  2008年   20627篇
  2007年   22754篇
  2006年   1570篇
  2005年   3047篇
  2004年   4160篇
  2003年   5004篇
  2002年   3050篇
  2001年   836篇
  2000年   944篇
  1999年   637篇
  1998年   350篇
  1997年   331篇
  1996年   220篇
  1995年   237篇
  1994年   205篇
  1993年   152篇
  1992年   301篇
  1991年   365篇
  1990年   368篇
  1989年   285篇
  1988年   258篇
  1987年   256篇
  1986年   213篇
  1985年   205篇
  1984年   129篇
  1983年   146篇
  1982年   109篇
  1981年   70篇
  1980年   97篇
  1979年   131篇
  1978年   85篇
  1977年   72篇
  1974年   84篇
  1973年   89篇
  1970年   77篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing.  相似文献   
22.
PURPOSE: Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, increases survival when combined with irinotecan-based chemotherapy in first-line treatment of metastatic colorectal cancer (CRC). This randomized, phase II trial compared bevacizumab plus fluorouracil and leucovorin (FU/LV) versus placebo plus FU/LV as first-line therapy in patients considered nonoptimal candidates for first-line irinotecan. PATIENTS AND METHODS: Patients had metastatic CRC and one of the following characteristics: age > or = 65 years, Eastern Cooperative Oncology Group performance status 1 or 2, serum albumin < or = 3.5 g/dL, or prior abdominal/pelvic radiotherapy. Patients were randomly assigned to FU/LV/placebo (n = 105) or FU/LV/bevacizumab (n = 104). The primary end point was overall survival. Secondary end points were progression-free survival, response rate, response duration, and quality of life. Safety was also assessed. RESULTS: Median survival was 16.6 months for the FU/LV/bevacizumab group and 12.9 months for the FU/LV/placebo group (hazard ratio, 0.79; P = .16). Median progression-free survival was 9.2 months (FU/LV/bevacizumab) and 5.5 months (FU/LV/placebo); hazard ratio was 0.50; P = .0002. Response rates were 26.0% (FU/LV/bevacizumab) and 15.2% (FU/LV/placebo) (P = .055); duration of response was 9.2 months (FU/LV/bevacizumab) and 6.8 months (FU/LV/placebo); hazard ratio was 0.42; P = .088. Grade 3 hypertension was more common with bevacizumab treatment (16% v 3%) but was controlled with oral medication and did not cause study drug discontinuation. CONCLUSION: Addition of bevacizumab to FU/LV as first-line therapy in CRC patients who were not considered optimal candidates for first-line irinotecan treatment provided clinically significant patient benefit, including statistically significant improvement in progression-free survival.  相似文献   
23.
24.

Introduction  

This paper presents the results of a study on the psychometric properties of an authorized Spanish version of the McMaster Family Assessment Device, a self-report measure of family functioning.  相似文献   
25.
26.
27.

Introduction  

Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies.  相似文献   
28.
29.
A benign esophageal leiomyoma with abnormally increased fluorine-18-fluorodeoxyglucose uptake on positron emission tomography (PET) was resected thoracoscopically. The tumor, of which the maximum standardized uptake value of the lesion was 4.7, was well defined and 38 mm in diameter. Neither mitotic activity nor degeneration was found histologically; and immunoreactivity for CD34, CD117, MIB-1, and glucose transporter-1 was negative immunohistochemically. A diagnosis of gastrointestinal stromal tumor was ruled out by an oncogenic kinase gene mutation study. This case cautions against PET-dependent evaluation for malignant potential of esophageal submucosal tumors.  相似文献   
30.
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