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   151333篇
  免费   10999篇
  国内免费   298篇
耳鼻咽喉   1411篇
儿科学   4285篇
妇产科学   3275篇
基础医学   23338篇
口腔科学   3981篇
临床医学   13875篇
内科学   29952篇
皮肤病学   2556篇
神经病学   14913篇
特种医学   5987篇
外国民族医学   21篇
外科学   18829篇
综合类   672篇
现状与发展   1篇
一般理论   138篇
预防医学   17010篇
眼科学   2446篇
药学   9006篇
  1篇
中国医学   263篇
肿瘤学   10670篇
  2023年   584篇
  2022年   908篇
  2021年   2368篇
  2020年   1692篇
  2019年   2534篇
  2018年   3051篇
  2017年   2581篇
  2016年   2892篇
  2015年   3218篇
  2014年   4439篇
  2013年   5838篇
  2012年   8993篇
  2011年   9040篇
  2010年   4749篇
  2009年   4840篇
  2008年   8090篇
  2007年   8334篇
  2006年   8012篇
  2005年   7586篇
  2004年   6656篇
  2003年   6285篇
  2002年   5779篇
  2001年   4969篇
  2000年   4871篇
  1999年   4439篇
  1998年   1933篇
  1997年   1625篇
  1996年   1662篇
  1995年   1351篇
  1994年   1243篇
  1993年   1170篇
  1992年   3013篇
  1991年   2761篇
  1990年   2641篇
  1989年   2486篇
  1988年   2263篇
  1987年   1977篇
  1986年   1906篇
  1985年   1809篇
  1984年   1307篇
  1983年   1131篇
  1982年   636篇
  1981年   556篇
  1980年   487篇
  1979年   981篇
  1978年   614篇
  1977年   529篇
  1974年   514篇
  1973年   507篇
  1972年   496篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
11.
12.
13.
14.
15.
16.
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients.  相似文献   
17.
18.

Background

Early dumping is a poorly defined and incompletely understood complication after Roux-en-Y gastric (RYGB).

Objective

We performed a mixed-meal tolerance test in patients after RYGB to address the prevalence of early dumping and to gain further insight into its pathophysiology.

Setting

The study was conducted in a regional hospital in the northern part of the Netherlands.

Methods

From a random sample of patients who underwent primary RYGB between 2008 and 2011, 46 patients completed the mixed-meal tolerance test. The dumping severity score for early dumping was assessed every 30 minutes. A sum score at 30 or 60 minutes of ≥5 and an incremental score of ≥3 points were defined as indicating a high suspicion of early dumping. Blood samples were collected at baseline, every 10 minutes during the first half hour, and at 60 minutes after the start.

Results

The prevalence of a high suspicion of early dumping was 26%. No differences were seen for absolute hematocrit value, inactive glucagon-like peptide-1, and vasoactive intestinal peptide between patients with or without early dumping. Patients at high suspicion of early dumping had higher levels of active glucagon-like peptide-1 and peptide YY.

Conclusion

The prevalence of complaints at high suspicion of early dumping in a random population of patients after RYGB is 26% in response to a mixed-meal tolerance test. Postprandial increases in both glucagon-like peptide-1 and peptide YY are associated with symptoms of early dumping, suggesting gut L-cell overactivity in this syndrome.  相似文献   
19.
Dynamic contrast-enhanced ultrasound (DCE-US) has been proposed as a powerful tool for cancer diagnosis by estimation of perfusion and dispersion parameters reflecting angiogenic vascular changes. This work was aimed at identifying which vascular features are reflected by the estimated perfusion and dispersion parameters through comparison with acoustic angiography (AA). AA is a high-resolution technique that allows quantification of vascular morphology. Three-dimensional AA and 2-D DCE-US bolus acquisitions were used to monitor the growth of fibrosarcoma tumors in nine rats. AA-derived vascular properties were analyzed along with DCE-US perfusion and dispersion to investigate the differences between tumor and control and their evolution in time. AA-derived microvascular density and DCE-US perfusion exhibited good agreement, confirmed by their spatial distributions. No vascular feature was correlated with dispersion. Yet, dispersion provided better cancer classification than perfusion. We therefore hypothesize that dispersion characterizes vessels that are smaller than those visible with AA.  相似文献   
20.
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