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   4626篇
  免费   274篇
  国内免费   25篇
耳鼻咽喉   48篇
儿科学   135篇
妇产科学   67篇
基础医学   710篇
口腔科学   435篇
临床医学   311篇
内科学   1076篇
皮肤病学   129篇
神经病学   396篇
特种医学   68篇
外科学   459篇
综合类   16篇
预防医学   428篇
眼科学   65篇
药学   345篇
中国医学   23篇
肿瘤学   214篇
  2024年   5篇
  2023年   47篇
  2022年   69篇
  2021年   161篇
  2020年   118篇
  2019年   161篇
  2018年   166篇
  2017年   141篇
  2016年   119篇
  2015年   172篇
  2014年   210篇
  2013年   254篇
  2012年   390篇
  2011年   469篇
  2010年   269篇
  2009年   218篇
  2008年   351篇
  2007年   314篇
  2006年   245篇
  2005年   235篇
  2004年   211篇
  2003年   174篇
  2002年   136篇
  2001年   29篇
  2000年   24篇
  1999年   31篇
  1998年   26篇
  1997年   17篇
  1996年   14篇
  1995年   12篇
  1994年   12篇
  1993年   11篇
  1992年   14篇
  1991年   18篇
  1990年   14篇
  1989年   12篇
  1988年   10篇
  1987年   4篇
  1986年   3篇
  1985年   3篇
  1984年   5篇
  1983年   3篇
  1982年   4篇
  1980年   3篇
  1979年   7篇
  1977年   3篇
  1970年   2篇
  1967年   1篇
  1966年   1篇
  1930年   1篇
排序方式: 共有4925条查询结果,搜索用时 546 毫秒
1.
2.
3.
4.
5.

Background  

Due to marginalization, trafficking violence, conflicts with the police and organic and social psychological problems associated with the drug, crack is one of the most devastating drugs currently in use. However, there is evidence that some users manage to stay alive and active while using crack cocaine for many years, despite the numerous adversities and risks involved with this behavior. In this context, the aim of the present study was to identify the strategies and tactics developed by crack users to deal with the risks associated with the culture of use by examining the survival strategies employed by long-term users.  相似文献   
6.
PURPOSE: Current treatment for febrile neutropenia (FN) includes hospitalization for evaluation, empiric broad-spectrum antibiotics, and other supportive care. Clinical trials have reported conflicting results when studying whether the colony-stimulating factors (CSFs) improve outcomes in patients with FN. This Cochrane Collaboration review was undertaken to further evaluate the safety and efficacy of the CSFs in patients with FN. METHODS: An exhaustive literature search was undertaken including major electronic databases (CANCERLIT, EMBASE, LILACS, MEDLINE, SCI, and the Cochrane Controlled Trials Register). All randomized controlled trials that compare CSFs plus antibiotics versus antibiotics alone for the treatment of established FN in adults and children were sought. A meta-analysis of the selected studies was performed. RESULTS: More than 8,000 references were screened, with 13 studies meeting eligibility criteria for inclusion. The overall mortality was not influenced significantly by the use of CSF (odds ratio [OR] = 0.68; 95% CI, 0.43 to 1.08; P = .1). A marginally significant result was obtained for the use of CSF in reducing infection-related mortality (OR = 0.51; 95% CI, 0.26 to 1.00; P = .05). Patients treated with CSFs had a shorter length of hospitalization (hazard ratio [HR] = 0.63; 95% CI, 0.49 to 0.82; P = .0006) and a shorter time to neutrophil recovery (HR = 0.32; 95% CI, 0.23 to 0.46; P < .00001). CONCLUSION: The use of the CSFs in patients with established FN caused by cancer chemotherapy reduces the amount of time spent in hospital and the neutrophil recovery period. The possible influence of the CSFs on infection-related mortality requires further investigation.  相似文献   
7.
8.
Insomnia in psychiatric patients is frequently underestimated in clinical practice. Usually drugs are prescribed for the treatment of this disorder but non-pharmacological intervention can be successfully used. The present study aimed at evaluating the efficacy of a two-session psychoeducational intervention in improving persistent non-organic insomnia and reducing the administration of PRN therapy in severely mentally ill patients. A pre-post study was performed on 36 psychiatric patients admitted to a residential psychiatric unit. The Nocturnal Sleep Onset Scale (NSOS) and Daytime Sleepiness Scale (DSS), the sleep onset latency, the time awake after sleep onset and the numbers of awakenings were gathered 2 weeks before the intervention (T0), immediately prior the intervention (T1), 2 weeks after the last session of the intervention (T2) and a 3-month follow-up (T3). The total number of administrations of PRN therapy from T0 to T1 and from T1 to T2 were also examined. A significant reduction was shown on the NSOS, the sleep onset latency and in the time awake after sleep onset from T1 to T2 and from T1 to T3, while no significant difference was found between T0 and T1. A significant decrease on the mean number of administrations of PRN therapy was also found between 15 days before the intervention (T0-T1) and 15 days after intervention (T1-T2). The initial results of this study seems to suggest the possible efficacy of a short-term psychoeducational intervention on improving persistent non-organic insomnia in severely mentally ill patients. Further control studies are necessary to confirm these findings.  相似文献   
9.
10.
Quantitative receptor autoradiography was used to study possible alterations of the densities of multiple serotonin (5-HT) receptor subtypes and of serotonin transporter in the brain of 5-HT(2C) receptor knockout mice. The radioligands employed were [(3)H]citalopram, [(3)H]WAY100,635, [(3)H]8-OH-DPAT, [(3)H]GR125743, [(3)H]sumatriptan, [(3)H]MDL100,907, [(125)I](+/-)DOI, [(3)H]mesulergine, [(3)H]5-HT, [(3)H]GR113808, and [(3)H]5-CT. As expected, radioligands that label 5-HT(2C) receptors showed a complete absence of labeling in mutant mice choroid plexus and significantly reduced densities in other brain regions expressing 5-HT(2C) receptors. With the rest of the radioligands, no significant alterations in the densities of labeled sites were found in any brain region. In situ hybridization showed no changes in 5-HT(2A) receptor and serotonin transporter mRNA levels, whereas 5-HT(2C) receptor mRNA levels were reduced in certain brain regions. The present results indicate that the mouse serotonergic system does not exhibit compensatory up- or down-regulation of the majority of its components (serotonin transporter and most 5-HT receptor subtypes) in response to the absence of 5-HT(2C) receptors.  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