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   10192篇
  免费   600篇
  国内免费   29篇
耳鼻咽喉   128篇
儿科学   396篇
妇产科学   260篇
基础医学   1342篇
口腔科学   150篇
临床医学   933篇
内科学   1979篇
皮肤病学   169篇
神经病学   1237篇
特种医学   212篇
外国民族医学   55篇
外科学   723篇
综合类   81篇
一般理论   13篇
预防医学   1238篇
眼科学   221篇
药学   1011篇
中国医学   23篇
肿瘤学   650篇
  2024年   12篇
  2023年   102篇
  2022年   268篇
  2021年   509篇
  2020年   250篇
  2019年   333篇
  2018年   346篇
  2017年   305篇
  2016年   319篇
  2015年   300篇
  2014年   420篇
  2013年   582篇
  2012年   882篇
  2011年   883篇
  2010年   456篇
  2009年   394篇
  2008年   643篇
  2007年   703篇
  2006年   645篇
  2005年   556篇
  2004年   540篇
  2003年   464篇
  2002年   409篇
  2001年   49篇
  2000年   25篇
  1999年   47篇
  1998年   64篇
  1997年   35篇
  1996年   31篇
  1995年   33篇
  1994年   29篇
  1993年   24篇
  1992年   13篇
  1991年   10篇
  1990年   12篇
  1989年   9篇
  1988年   9篇
  1987年   7篇
  1986年   8篇
  1985年   5篇
  1983年   7篇
  1982年   9篇
  1981年   14篇
  1980年   7篇
  1979年   5篇
  1978年   5篇
  1977年   4篇
  1976年   5篇
  1974年   5篇
  1971年   4篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Summary Using data collected in a large scale community survey, some aspects of illness behaviour were compared in Asian-born and British-born residents of West London. Asian-born men were found to be far more likely to consult a general practitioner than British men, although the former group reported less long-standing illness and emotional distress than the latter. Self-assessed health among Asian men was significantly worse than among native men, and it was this health measure which was found to have the greatest effect on general practice consultations when a linear model was constructed. Differences in illness behaviour between Asian-born an indigenous women were not significant.  相似文献   
22.
Health Services and Outcomes Research Methodology - An interrupted time series with a parallel control group (ITS-CG) design is a powerful quasi-experimental design commonly used to evaluate the...  相似文献   
23.
24.
25.
26.
27.
28.
The central action of the potential antidepressant drug pizotifen (Sandomigran) was studied in mice, rats and rabbits. Pizotifen in doses up to 10 mg/kg i.p. was ineffective in classic tests for antidepressant activity. It neither antagonized the effects of reserpine in rats (hypothermia, ptosis) nor potentiated the effects of amphetamine (in mice and rats), nialamide or L-dopa (in mice) on locomotor activity. However, its antidepressant activity was found in the despair test in rats.On the other hand, pizotifen inhibited the head twitch reaction induced by L-5-hydroxytryptophan in mice (ED50=0.009 mg/kg, i.p.) and by 5-methoxytryptamine (+tranylcypromine) in rats (ED50=0.45 mg/kg, i.p.). It also antagonized tryptamine-induced clonic convulsions of fore-paws in rats (ED50=0.35 mg/kg, i.p.), and in doses of 5–10 mg/kg s.c. inhibited hyperthermia produced by LSD in rabbits. Finally, pizotifen (0.1–0.3 mg/kg, i.v.) inhibited or abolished LSD- or quipazine-induced stimulation of the hind limb flexor reflex of spinal rats; the above effect was not due to noradrenolytic action of the drug. These results suggest that pizotifen strongly blocks the central postsynaptic serotonin receptors.  相似文献   
29.
PURPOSE: ZD6126 is a novel vascular targeting agent currently undergoing clinical evaluation. It acts by destabilizing the microtubulin of fragile and proliferating neoendothelial cells in tumors. The drug leads to blood vessel congestion, the selective destruction of the vasculature, and extensive necrosis in experimental tumors. The aim of the study reported here was to assess the ability of dynamic contrast enhanced magnetic resonance imaging (MRI) to measure the antivascular effects of ZD6126 in tumors. EXPERIMENTAL DESIGN: The work was carried out in mice bearing C38 colon adenocarcinoma and in patients with advanced cancers. MRI was performed before and 6 h (human tumors) or 24 h (C38 tumors) after i.v. drug administration. Contrast agent (gadolinium diethylenetriaminepentaacetate) enhancement was characterized by the initial area under the gadolinium diethylenetriaminepentaacetate uptake versus time curve (IAUC). IAUC reflects blood flow, vascular permeability, and the fraction of interstitial space. RESULTS: The median IAUC was reduced in all C38 tumors after ZD6126 administration [by 6-48% at 50 mg/kg (n = 3)], 58-91% at 100 mg/kg (n = 4), and 11-93% at 200 mg/kg (n = 6). In contrast, the administration of vehicle only led to no consistent change in median IAUC (n = 4). The ZD6126-induced changes in median IAUC appeared to be dose dependent (P = 0.045). No ZD6126-induced changes were apparent in murine muscle. Similar effects were seen in preliminary data from human tumors (11 tumors studied, 9 patients). At doses of 80 mg/m(2) and higher, the median IAUC post-ZD6126 treatment was reduced in all of the tumors studied (8 tumors, 6 patients) to 36-72% from the baseline value. There was a significant trend of increasing reductions with increasing exposure (P < 0.01). No drug-induced changes in human muscle or spleen IAUC were apparent. The reproducibility of the median IAUC parameter was investigated in patients. In 19 human tumors (measured in 19 patients) inter- and intratumor coefficients of variation were 64 and 18%. CONCLUSIONS: The contrast enhanced-MRI measured median IAUC is a useful end point for quantifying ZD6126 antivascular effects in human tumors.  相似文献   
30.
Glomerulocystic disease (GCD) is a very rare condition. Only two previous reports have linked this condition with hepatoblastoma. We report a neonate with US evidence of grossly enlarged echogenic kidneys and features typical of hepatic fibrosis, complicated by the presence of a hepatoblastoma. The report discusses the differential diagnosis and highlights GCD as one cause of large, bright kidneys on US. It also adds further evidence to the suggested association between GCD and hepatoblastoma. Received: 15 May 1997 Accepted: 24 February 1998  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