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   18363篇
  免费   1228篇
  国内免费   159篇
耳鼻咽喉   266篇
儿科学   448篇
妇产科学   232篇
基础医学   2290篇
口腔科学   321篇
临床医学   1519篇
内科学   4499篇
皮肤病学   383篇
神经病学   1305篇
特种医学   687篇
外科学   2621篇
综合类   261篇
一般理论   23篇
预防医学   1499篇
眼科学   414篇
药学   1185篇
中国医学   65篇
肿瘤学   1732篇
  2023年   110篇
  2022年   186篇
  2021年   424篇
  2020年   287篇
  2019年   395篇
  2018年   438篇
  2017年   399篇
  2016年   448篇
  2015年   513篇
  2014年   631篇
  2013年   804篇
  2012年   1330篇
  2011年   1278篇
  2010年   810篇
  2009年   626篇
  2008年   1165篇
  2007年   1280篇
  2006年   1130篇
  2005年   1169篇
  2004年   1021篇
  2003年   1084篇
  2002年   1021篇
  2001年   234篇
  2000年   216篇
  1999年   217篇
  1998年   206篇
  1997年   202篇
  1996年   166篇
  1995年   156篇
  1994年   110篇
  1993年   103篇
  1992年   130篇
  1991年   113篇
  1990年   99篇
  1989年   96篇
  1988年   87篇
  1987年   87篇
  1986年   77篇
  1985年   75篇
  1984年   63篇
  1983年   67篇
  1982年   46篇
  1981年   44篇
  1980年   45篇
  1979年   38篇
  1978年   41篇
  1977年   46篇
  1976年   36篇
  1974年   35篇
  1970年   29篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
81.
82.
Background: Opioids are commonly used in conjunction with sedative drugs to provide anesthesia. Previous studies have shown that opioids reduce the clinical requirements of sedatives needed to provide adequate anesthesia. Processed electroencephalographic parameters, such as the Bispectral Index (BIS; Aspect Medical Systems, Newton, MA) and Auditory Evoked Potential Index (AAI; Alaris Medical Systems, San Diego, CA), can be used intraoperatively to assess the depth of sedation. The aim of this study was to characterize how the addition of opioids sufficient to change the clinical level of sedation influenced the BIS and AAI.

Methods: Twenty-four adult volunteers received a target-controlled infusion of remifentanil (0-15 ng/ml) and inhaled sevoflurane (0-6 vol%) at various target concentration pairs. After reaching pseudo-steady state drug levels, the modified Observer's Assessment of Alertness/Sedation score, BIS, and AAI were measured at each target concentration pair. Response surface pharmacodynamic interaction models were built using the pooled data for each pharmacodynamic endpoint.

Results: Response surface models adequately characterized all pharmacodynamic endpoints. Despite the fact that sevoflurane-remifentanil interactions were strongly synergistic for clinical sedation, BIS and AAI were minimally affected by the addition of remifentanil to sevoflurane anesthetics.  相似文献   

83.
84.
85.
During a survey of the parasite fauna of the euryhaline notothenioid fish Eleginops maclovinus (Cuvier) caught in brackish water creeks in the Falkland Islands, small white cysts were observed in the mesenteries and on the surfaces of the visceral organs and heart. On dissection these proved to be plasmodia of a species of the myxosporean genus Henneguya. This is the first record of a member of this genus from a marine or euryhaline fish in the south-west Atlantic. A comparison of the spore of our species with other species in the genus convinced us that our species is new. This paper describes it as Henneguya shackletoni sp. nov. after the Shackleton Fund which funded the study.  相似文献   
86.
87.
88.
An important treatment goal for pediatric nephrology caregivers is the optimization of a child's capacity for normal growth and development. However, the physiologic and metabolic derangements associated with chronic kidney disease (CKD) significantly alter these processes, creating important challenges in the care of affected children. Evidence-based clinical practice guidelines support early recognition and treatment of CKD-related complications to improve growth and development and, ultimately, quality of life for children with this chronic condition.  相似文献   
89.
Mycosis fungoides (M.F.) is a rare cutaneous malignancy of childhood and adolescence. The disease commonly presents with the classic sequence of erythematous patches and plaques. Hypopigmentation as the presenting symptom is distinctly rare. This is the 9th case report of M.F. presenting with hypopigmentation in a patient under 20 years of age. The disease was only partially controlled with PUVA therapy, necessitating nitrogen mustard treatment.  相似文献   
90.
The effects were studied of a toxin (Bainh) isolated from the secretion of the Caribbean sea anemone Bunodosoma granulifera on electrical and mechanical activities of rat ventricular muscle. The effects on the ionic currents of single rat and dog ventricular cardiomyocytes were studied using the whole-cell recording patch-clamp technique. In the concentration range from 1 to 10 mg/ml, Bainh increased the force of contraction and induced an increase in action potential duration of ventricular multicellular preparations. In single cardiomyocytes, at concentrations up to 10 mg/ml Bainh showed no significant effects on the sodium current. However, at 0.5–1 mg/ml it increased the L-type Ca current (ICaL) by 25–50%. This increase in ICaL was not voltage dependent and was reversible after washout. The transient outward current was not significantly affected by Bainh (1–10 mg/ml). In this concentration range, Bainh markedly (≈75%) increased the inward-going rectifier current, IK1. This effect that was not voltage dependent and was fully reversible upon returning to control solution. It is suggested that these effects on ionic currents could explain the positive inotropic action of Bainh on cardiac multicellular preparations.  相似文献   
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