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   21643篇
  免费   1554篇
  国内免费   203篇
耳鼻咽喉   358篇
儿科学   426篇
妇产科学   438篇
基础医学   2845篇
口腔科学   545篇
临床医学   2027篇
内科学   4476篇
皮肤病学   616篇
神经病学   1388篇
特种医学   1281篇
外科学   2823篇
综合类   787篇
现状与发展   1篇
一般理论   14篇
预防医学   1084篇
眼科学   728篇
药学   1662篇
  1篇
中国医学   178篇
肿瘤学   1722篇
  2023年   175篇
  2022年   115篇
  2021年   774篇
  2020年   450篇
  2019年   553篇
  2018年   726篇
  2017年   532篇
  2016年   645篇
  2015年   845篇
  2014年   1041篇
  2013年   1117篇
  2012年   1725篇
  2011年   1685篇
  2010年   970篇
  2009年   902篇
  2008年   1201篇
  2007年   1196篇
  2006年   1141篇
  2005年   1088篇
  2004年   851篇
  2003年   705篇
  2002年   576篇
  2001年   547篇
  2000年   525篇
  1999年   428篇
  1998年   204篇
  1997年   192篇
  1996年   133篇
  1995年   137篇
  1994年   119篇
  1993年   107篇
  1992年   169篇
  1991年   176篇
  1990年   149篇
  1989年   155篇
  1988年   138篇
  1987年   160篇
  1986年   120篇
  1985年   111篇
  1984年   83篇
  1983年   81篇
  1982年   46篇
  1980年   41篇
  1979年   61篇
  1977年   50篇
  1975年   40篇
  1974年   39篇
  1973年   37篇
  1972年   38篇
  1969年   41篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
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   
3.
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   
4.
5.
6.
The midwifery art has emphasised the uniqueness of human beings throughout its Nordic history. The educated Nordic midwife has in the last decade celebrated several hundred years of memories. This article studies how the key ideas of the midwifery art and patterns of ideas become evident in the zeitgeist from the beginning of the 19th century to the millennium in the Nordic countries. The legacy and pattern of ideas of the art of midwifery are interpreted in relation to the texts of the selected historical sources and based on Ricoeur's phenomenological-hermeneutic approach to the text and further to the dedication of understanding and interpretation. The historical sources refer to unprinted primary sources from historical archives and printed secondary and tertiary sources. The patterns of ideas include a tripartite whole: the true cultivation of the head, the philosophy and aesthetics of the hand, the strength of the heart and the drive of calling. These ideas open for unique visions and attest to the evident in modern midwives. Today's midwives have academic training with examinations, and the education is based on scientific evidence. The midwife profession is authorised by the state and supervised by the authorities.  相似文献   
7.
The use of multifunctional materials for water remediation is a modern approach where adsorption phenomena and heterogeneous photocatalysis can be applied for the removal of pollutants. Since the ideal remediation system should be able to remove both organic and inorganic pollutants, a crucial aspect to consider is the knowledge of operational parameters affecting the removal process, especially when heavy metal ions are present in concoction as in real systems. Given the proven efficiency of multifunctional TiO2/Alg/FeNPs magnetic beads for the removal of model organic pollutants, this study investigated the possibility to exploit such system also for the removal of mixed heavy metals (MHM), specifically Cr(III), Cu(II), and Pb(II) ions, under ultraviolet irradiation at a wavelength of 254 nm. After a preliminary screening on the optimal catalyst loading, operating parameters such as the initial concentration of metal ions, contact and irradiation time, and pH were investigated to optimize the removal of metal ions using response surface methodology (RSM) via Box–Behnken design. Starting from a MHM solution containing 44 ppm of each metal ion, the removal of Pb(II), Cr(III), and Cu(II) ions in the aqueous solution was nearly completed (>98.4%) for all three ions within 72 min of irradiation at almost neutral pH (pH = 6.8). The stability of TiO2/Alg/FeNPs was confirmed by retrieving and reusing the beads in three consecutive cycles of heavy metals removal without observing significant changes in catalyst efficiency.  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