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   1631篇
  免费   89篇
  国内免费   99篇
耳鼻咽喉   13篇
儿科学   55篇
妇产科学   7篇
基础医学   251篇
口腔科学   26篇
临床医学   186篇
内科学   312篇
皮肤病学   62篇
神经病学   149篇
特种医学   116篇
外科学   113篇
综合类   37篇
预防医学   79篇
眼科学   183篇
药学   183篇
肿瘤学   47篇
  2022年   11篇
  2021年   17篇
  2020年   15篇
  2019年   19篇
  2018年   24篇
  2017年   19篇
  2016年   20篇
  2015年   18篇
  2014年   27篇
  2013年   44篇
  2012年   45篇
  2011年   62篇
  2010年   47篇
  2009年   49篇
  2008年   65篇
  2007年   101篇
  2006年   62篇
  2005年   62篇
  2004年   43篇
  2003年   59篇
  2002年   55篇
  2001年   62篇
  2000年   52篇
  1999年   46篇
  1998年   60篇
  1997年   54篇
  1996年   41篇
  1995年   35篇
  1994年   35篇
  1993年   42篇
  1992年   26篇
  1991年   31篇
  1990年   25篇
  1989年   46篇
  1988年   42篇
  1987年   36篇
  1986年   30篇
  1985年   22篇
  1984年   21篇
  1983年   12篇
  1980年   16篇
  1979年   15篇
  1978年   11篇
  1977年   13篇
  1975年   13篇
  1973年   11篇
  1971年   11篇
  1970年   11篇
  1968年   13篇
  1966年   16篇
排序方式: 共有1819条查询结果,搜索用时 15 毫秒
41.
Electrophysiological Response to Ethanol in P and NP Rats   总被引:1,自引:0,他引:1  
Event-related potentials (ERPs) have been successfully used in human subjects to evaluate alcoholics as well as those at risk for the future development of alcoholism. In the present study, two lines of rats, those with a preference for ethanol consumption (P) and those not preferring (NP) to drink ethanol were studied using ERP-producing stimuli. Rats were implanted with electrodes in the frontal cortex and dorsal hippocampus (DHPC). A passive auditory "oddball" paradigm was used to record ERP responses following saline and two doses (0.5, 1.0 g/kg) of ethanol. P and NP rats differed under the saline condition in that P rats had smaller N1-like ERP components and larger P2 waves in both cortex and hippocampus. P and NP rats were also found to differ in response to ethanol administration. NP rats evidenced dose-dependent reductions in ERP component amplitudes such as the N1 recorded from cortical sites. P rats did not have such reductions in N1 amplitudes and in fact, displayed increased N1 amplitudes in hippocampal sites. These studies provide further electrophysiological evidence that rats with a genetically influenced preference for ethanol consumption differ from nonpreferring rats at baseline and have a less intense depressant or more stimulating response to ethanol challenge.  相似文献   
42.
43.
A 54-year-old man was treated with weekly 24-h infusion of high-dose 5-fluorouracil (2600 mg/m2) and leucovorin (100 mg/m2) for metastatic colon cancer. At first, he tolerated the treatment well and no significant toxicity was identified. After a total of eight courses of treatment, a stable disease was observed, but mild shortness of breath was found on occasion. The patient had no previous history of cardiac disease and the heart performance assessed by left ventricular ejection fraction before treatment was normal. Unfortunately, acute pulmonary edema with lethal cardiogenic shock occurred during the ninth course of treatment, in spite of intensive medical treatment. The chest X-ray showed extreme cardiomegaly. Repeated assessment of his heart function by echocardiogram and ventricular ejection fraction revealed a very poor cardiac performance. Toxic cardiogenic shock during weekly 24-h infusion of high-dose 5-fluorouracil and leucovorin is extremely rare. To the best of our knowledge, no case has been reported in the English literature. We report a case and the relevant literature about the incidence, clinical picture and possible pathophysiology on 5-fluorouracil-related cardioxicity is reviewed.   相似文献   
44.
Hendrix  SL  Cochrane  BB  Nygaard  IE  沈平虎 《英国医学杂志》2006,9(1):48-49
问题:在绝经后健康妇女中,激素治疗(hormone therapy,HT)对尿失禁(urinary incontinence,UI)的效果如何?  相似文献   
45.
46.
47.
48.
49.
BACKGROUND: Cytosolic aldehyde dehydrogenase, or ALDH1A1, functions in ethanol detoxification, metabolism of neurotransmitters, and synthesis of retinoic acid. Because the promoter region of a gene can influence gene expression, the ALDH1A1 promoter regions were studied to identify polymorphism, to assess their functional significance, and to determine whether they were associated with a risk for developing alcoholism. METHODS: Sequence analysis was performed in the promoter region by using Asian, Caucasian, and African American subjects. The resulting polymorphisms were assessed for frequency in Asian, Caucasian, Jewish, and African American populations and tested for associations with alcohol dependence in Asian and African American populations of alcoholics and controls. The functional significance of each polymorphism was determined through in vitro expression analysis by using HeLa and HepG2 cells. RESULTS: Two polymorphisms, a 17 base pair (bp) deletion (-416/-432) and a 3 bp insertion (-524), were discovered in the ALDH1A1 promoter region: ALDH1A1*2 and ALDH1A1*3, respectively. ALDH1A1*2 was observed at frequencies of 0.035, 0.023, 0.023, and 0.012 in the Asian, Caucasian, Jewish, and African American populations, respectively. ALDH1A1*3 was observed only in the African American population, at a frequency of 0.029. By using HeLa and HepG2 cells for in vitro expression, the activity of the luciferase reporter gene was significantly decreased after transient transfection of ALDH1A1*3-luciferase compared with the wild-type construct ALDH1A1*1-luciferase. In an African American population, a trend for higher frequencies of the ALDH1A1*2 and ALDH1A1*3 alleles was observed in a population of alcoholics (p = 0.03 and f = 0.12, respectively) compared with the control population. CONCLUSIONS: ALDH1A1*2 and ALDH1A1*3 may influence ALDH1A1 gene expression. Both ALDH1A1*2 and ALDH1A1*3 produce a trend in an African American population that may be indicative of an association with alcoholism; however, more samples are required to validate this observation. The underlying mechanisms contributing to these trends are still unknown.  相似文献   
50.
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