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   199029篇
  免费   2657篇
  国内免费   244篇
耳鼻咽喉   1597篇
儿科学   6981篇
妇产科学   3463篇
基础医学   19880篇
口腔科学   2109篇
临床医学   14445篇
内科学   35778篇
皮肤病学   1413篇
神经病学   17955篇
特种医学   10154篇
外科学   31861篇
综合类   3096篇
现状与发展   2篇
一般理论   14篇
预防医学   19177篇
眼科学   3619篇
药学   11292篇
中国医学   876篇
肿瘤学   18218篇
  2023年   190篇
  2022年   541篇
  2021年   958篇
  2020年   519篇
  2019年   685篇
  2018年   22665篇
  2017年   17864篇
  2016年   20195篇
  2015年   1905篇
  2014年   2004篇
  2013年   2070篇
  2012年   9041篇
  2011年   22912篇
  2010年   19905篇
  2009年   12444篇
  2008年   20830篇
  2007年   22951篇
  2006年   1801篇
  2005年   3333篇
  2004年   4309篇
  2003年   5093篇
  2002年   3113篇
  2001年   871篇
  2000年   964篇
  1999年   598篇
  1998年   340篇
  1997年   319篇
  1996年   169篇
  1995年   189篇
  1994年   190篇
  1993年   125篇
  1992年   199篇
  1991年   265篇
  1990年   269篇
  1989年   208篇
  1988年   174篇
  1987年   175篇
  1986年   132篇
  1985年   126篇
  1984年   92篇
  1983年   90篇
  1982年   61篇
  1980年   71篇
  1979年   64篇
  1974年   58篇
  1970年   53篇
  1969年   63篇
  1938年   60篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Social Psychiatry and Psychiatric Epidemiology - The negative effect of catastrophic financial loss on suicide risk is widely perceived but hardly studied in-depth because of various difficulties...  相似文献   
2.
3.
Rhabdomyolysis is a syndrome of skeletal muscle injury with release of cellular constituents such as potassium,phosphate,urate and intracellular proteins such as myoglobin into the circulation,which may cause complications including acute kidney injury,electrolyte disturbance and cardiac instability.Abnormal liver function tests are frequently observed in cases of severe rhabdomyolysis.Typically,there is an increase in serum aminotransferases,namely aspartate aminotransferase and alanine aminotransferase.This raises the question of liver injury and often triggers a pathway of investigation which may lead to a liver biopsy.However,muscle can also be a source of the increased aminotransferase activity.This review discusses the dilemma of finding abnormal liver function tests in the setting of muscle injury and the potential implications of such an association.It delves into some of the clinical and experimental evidence for correlating muscle injury to raised aminotransferases,and discusses pathophysiological mechanisms such as oxidative stress which may cause actual liver injury.Serum aminotransferases lack tissue specificity to allow clinicians to distinguish primary liver injury from muscle injury.This review also explores potential approaches to improve the accuracy of our diagnostic tools,so that excessive or unnecessary liver investigations can be avoided.  相似文献   
4.
Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm3. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation.  相似文献   
5.
6.
7.
Abstract

Objective

Ras wild-type metastatic colorectal cancers (mCRC) may be treated with anti-vascular endothelial growth factor (VEGF) or anti-epidermal growth factor receptor (EGFR) agents. We aim to estimate patients’ preferences for mCRC treatment and relative importance of cost, efficacy improvement, avoidance of side effects and therapy convenience, and relative uptake between profiles that resemble Bevacizumab (anti-VEGF) and Cetuximab (anti-EGFR), two commonly prescribed mCRC targeted therapies.  相似文献   
8.
9.
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