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   78539篇
  免费   8069篇
  国内免费   424篇
耳鼻咽喉   1229篇
儿科学   2203篇
妇产科学   1686篇
基础医学   9222篇
口腔科学   1449篇
临床医学   9335篇
内科学   15626篇
皮肤病学   1671篇
神经病学   7209篇
特种医学   2952篇
外科学   13402篇
综合类   909篇
现状与发展   2篇
一般理论   67篇
预防医学   7892篇
眼科学   1840篇
药学   4878篇
  2篇
中国医学   80篇
肿瘤学   5378篇
  2023年   964篇
  2022年   880篇
  2021年   2000篇
  2020年   1677篇
  2019年   1764篇
  2018年   2448篇
  2017年   1921篇
  2016年   2102篇
  2015年   2261篇
  2014年   3214篇
  2013年   4226篇
  2012年   5135篇
  2011年   5160篇
  2010年   3256篇
  2009年   3170篇
  2008年   4450篇
  2007年   4632篇
  2006年   4537篇
  2005年   4259篇
  2004年   3895篇
  2003年   3682篇
  2002年   3362篇
  2001年   1118篇
  2000年   991篇
  1999年   1064篇
  1998年   956篇
  1997年   838篇
  1996年   847篇
  1995年   845篇
  1994年   637篇
  1993年   562篇
  1992年   685篇
  1991年   630篇
  1990年   601篇
  1989年   611篇
  1988年   548篇
  1987年   472篇
  1986年   481篇
  1985年   533篇
  1984年   468篇
  1983年   391篇
  1982年   356篇
  1981年   298篇
  1980年   283篇
  1979年   281篇
  1978年   299篇
  1977年   243篇
  1975年   226篇
  1974年   235篇
  1973年   229篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Rising malpractice rates and damages to finances and reputations caused by litigation are leading risk managers to seek new solutions to reduce the frequency and severity of malpractice. Any effort to meet the challenges of malpractice must consider three areas: the informed consent process, expectation management and physician communication. Technology is emerging as an important tool that can help risk managers better address these critical areas. This article explores the realities of malpractice today — specifically the factors behind the majority of cases and discusses how new tools can help risk managers.  相似文献   
23.
24.
25.
The purpose of this study was to determine if changes in hindlimb motoneuron membrane electrical properties occur 4–6 months after spinal transection in the adult animal. Eight acute and nine chronic animals were spinalized at T12. Intracellular recordings from motoneurons innervating the triceps surae were performed. Membrane electrical properties, including resting potential, action potential peak amplitude, afterhyperpolarization duration, rheobasic current, input resistance and axonal conduction velocity were measured. There were no statistical differences found between group means or frequency distributions in the membrane properties of motoneurons assessed from acute and chronic spinal animals. Thus, alteration of motoneuron membrane properties does not appear to be a major contributing factor to the hyperexcitable hindlimb reflex activity demonstrated by chronic spinal animals.  相似文献   
26.
27.
Cerebrospinal fluid (CSF) from 7 patients with infantile spasms (mean age: 6.7 months) was collected before and after treatment with adrenocorticotropic hormone (ACTH). The concentration of neurotransmitter metabolites was analyzed using high-performance liquid chromatography and compared to the metabolite concentration in the CSF from 7 age-matched controls (mean age: 6.1 months). Pretreatment levels of CSF 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid, 3-methoxy-4-hydroxyphenyl glycol (MHPG), and kynurenine were significantly lower in infantile spasm patients compared to controls. Following treatment, marked increases in 5-HIAA and decreases in kynurenine levels were observed in the CSF of the 5 infants whose seizures were eliminated or reduced by ACTH. In the 2 nonresponders 5-HIAA levels decreased. The level of MHPG was reduced slightly in 5 infants, including the 2 nonresponders, and was increased in 2 responders. CSF homovanillic acid levels increased in 4 infantile spasm infants and decreased in 3 following ACTH. These data demonstrate that the presence of seizures in infantile spasms is associated with a significant decrease in serotonergic activity and that elimination of seizures by ACTH is accompanied by increased serotonin turnover. The simultaneous increase of 5-HIAA and decrease of kynurenine, an alternate metabolite of tryptophan, suggests an underlying disturbance of tryptophan metabolism in infantile spasms. The possibility that elimination of seizures by ACTH may be related to decreased production of certain kynurenine metabolites, particularly quinolinic acid, is discussed.  相似文献   
28.
29.
Memory performance of elderly patients in the early stages of Alzheimer's disease (DAT) was compared with that of elderly control subjects. In explicit tests of recognition memory, which involve conscious recollection, the DAT patients were grossly impaired. In implicit tests of anagram solution and wordstem completion, which do not require conscious recollection, the DAT patients were not impaired. These findings further support the idea that a separate memory system, episodic memory, underlies conscious recollection, that it is this system which is most commonly damaged in amnesia, and that memory systems not involving conscious recollection may be spared in the early stages of Alzheimer's disease.  相似文献   
30.
This study examined the use and effectiveness of the Alert assessment form. The form is part of the Alert system, used by one large acute care hospital to identify patients with a propensity for violence. All reported incidents of patient violence from August 1, 2003, through December 31, 2004, were included in patient charts. One hundred seventeen violent patient charts were reviewed and compared with 161 non-violent patient charts, randomly chosen from the same time period. Overall use of the Alert assessment form for violent and non-violent patients was 75.7% and 35.4%, respectively. The assessment form was found to have moderate sensitivity (71%) and high specificity (94%). It is reasonably effective in identifying potentially violent or aggressive patients when it is used according to protocol. Efforts to improve the tool are warranted, as is evaluation of its benefit in settings with low prevalence of violence. Also, greater effort must be taken to prevent violence once an aggressive patient has been identified.  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