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   24705篇
  免费   1262篇
  国内免费   149篇
耳鼻咽喉   356篇
儿科学   396篇
妇产科学   493篇
基础医学   3158篇
口腔科学   622篇
临床医学   1834篇
内科学   6825篇
皮肤病学   274篇
神经病学   1844篇
特种医学   710篇
外科学   4224篇
综合类   99篇
一般理论   1篇
预防医学   729篇
眼科学   370篇
药学   1673篇
中国医学   42篇
肿瘤学   2466篇
  2023年   140篇
  2022年   147篇
  2021年   549篇
  2020年   299篇
  2019年   342篇
  2018年   495篇
  2017年   352篇
  2016年   437篇
  2015年   422篇
  2014年   589篇
  2013年   741篇
  2012年   1103篇
  2011年   1171篇
  2010年   642篇
  2009年   559篇
  2008年   1115篇
  2007年   1166篇
  2006年   1083篇
  2005年   1026篇
  2004年   1006篇
  2003年   998篇
  2002年   1013篇
  2001年   892篇
  2000年   930篇
  1999年   804篇
  1998年   293篇
  1997年   216篇
  1996年   200篇
  1995年   185篇
  1994年   161篇
  1993年   144篇
  1992年   599篇
  1991年   626篇
  1990年   533篇
  1989年   540篇
  1988年   522篇
  1987年   497篇
  1986年   427篇
  1985年   429篇
  1984年   313篇
  1983年   238篇
  1979年   231篇
  1978年   133篇
  1977年   139篇
  1974年   128篇
  1973年   120篇
  1972年   137篇
  1971年   127篇
  1969年   138篇
  1967年   128篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
International Journal of Clinical Oncology - The practice of cancer diagnosis disclosure to children has been changed with the times. The regulations of clinical trials in the 2000s might change...  相似文献   
2.
3.

Background

There were few studies assessed the postoperative sarcopenia in patients with cancers. The objective of present study was to assess whether postoperative development of sarcopenia could predict a poor prognosis in patients with adenocarcinoma of esophagogastric junction, (AEG) and upper gastric cancer (UGC).

Methods

Patients with AEG and UGC who were judged as non-sarcopenic before surgery were reassessed the presence of postoperative development of sarcopenia 6 months after surgery. Patients were divided into the development group or non-development group, and clinicopathological factors and prognosis between these two groups were analyzed.

Results

The 5-year overall survival rates were significantly poorer in the development group than non-development group (68.0% vs. 92.6%, P?=?0.0118). Multivariate analyses showed that postoperative development of sarcopenia was an independent prognostic factor for poor overall survival (P?=?0.0237).

Conclusions

Postoperative development of sarcopenia was associated with a poor prognosis in patients with AEG and UGC.  相似文献   
4.
5.
6.
7.
8.
9.
Previously, we demonstrated that wrapping dextran fluorescein anionic/cationic lipid complexes with neutral lipids produced a stable formulation that markedly increased the duration of the compound in plasma after intravenous administration to rats. The improved drug-delivery properties of the wrapped liposomes (WL) relative to other formulations suggested that this technology could offer important advantages for the administration of other polyanionic drugs, including antisense oligodeoxynucleotides (ODN). In the present study, we investigated the value of WL for formulating fluorescence-labeled phosphorothioated ODN (F-ODN). WL encapsulating F-ODN/cationic lipid complexes were prepared efficiently using similar methodology to that used in our earlier study. Studies confirmed that these WL were stable in vitro. Following intravenous administration to mice, free F-ODN and naked F-ODN/cationic lipid complexes were rapidly eliminated whereas administration of the WL resulted in high blood concentrations of drug that were maintained for several hours. Additional studies were conducted in mice that were inoculated with tumor cells (Caki-1 xenograft model, human kidney); in these experiments, intravenous administration of WL delivered 13 times more F-ODN to the tumor site than achieved after injection of free F-ODN.  相似文献   
10.
OBJECTIVE: The Karolinska sleepiness scale (KSS) is frequently used for evaluating subjective sleepiness. The main aim of the present study was to investigate the validity and reliability of the KSS with electroencephalographic, behavioral and other subjective indicators of sleepiness. METHODS: Participants were 16 healthy females aged 33-43 (38.1+/-2.68) years. The experiment involved 8 measurement sessions per day for 3 consecutive days. Each session contained the psychomotor vigilance task (PVT), the Karolinska drowsiness test (KDT-EEG alpha & theta power), the alpha attenuation test (AAT-alpha power ratio open/closed eyes) and the KSS. RESULTS: Median reaction time, number of lapses, alpha and theta power density and the alpha attenuation coefficients (AAC) showed highly significant increase with increasing KSS. The same variables were also significantly correlated with KSS, with a mean value for lapses (r=0.56). CONCLUSIONS: The KSS was closely related to EEG and behavioral variables, indicating a high validity in measuring sleepiness. SIGNIFICANCE: KSS ratings may be a useful proxy for EEG or behavioral indicators of sleepiness.  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