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   6864篇
  免费   755篇
  国内免费   15篇
耳鼻咽喉   53篇
儿科学   196篇
妇产科学   122篇
基础医学   1208篇
口腔科学   182篇
临床医学   689篇
内科学   1220篇
皮肤病学   110篇
神经病学   696篇
特种医学   445篇
外国民族医学   1篇
外科学   681篇
综合类   177篇
一般理论   5篇
预防医学   621篇
眼科学   201篇
药学   623篇
中国医学   2篇
肿瘤学   402篇
  2021年   83篇
  2019年   78篇
  2018年   87篇
  2017年   84篇
  2016年   81篇
  2015年   106篇
  2014年   116篇
  2013年   241篇
  2012年   269篇
  2011年   257篇
  2010年   180篇
  2009年   188篇
  2008年   257篇
  2007年   262篇
  2006年   269篇
  2005年   331篇
  2004年   315篇
  2003年   282篇
  2002年   248篇
  2001年   215篇
  2000年   237篇
  1999年   223篇
  1998年   133篇
  1997年   130篇
  1996年   141篇
  1995年   110篇
  1994年   102篇
  1993年   102篇
  1992年   172篇
  1991年   149篇
  1990年   145篇
  1989年   136篇
  1988年   139篇
  1987年   144篇
  1986年   124篇
  1985年   129篇
  1984年   100篇
  1983年   100篇
  1982年   62篇
  1980年   67篇
  1979年   95篇
  1978年   55篇
  1977年   58篇
  1976年   52篇
  1974年   56篇
  1973年   66篇
  1971年   55篇
  1970年   52篇
  1969年   53篇
  1968年   57篇
排序方式: 共有7634条查询结果,搜索用时 531 毫秒
1.
2.
Effects of acute liver injury on blood coagulation   总被引:1,自引:0,他引:1  
Summary.  The mechanisms leading to the hemostatic changes of acute liver injury are poorly understood. To study these further we have assessed coagulation and immune changes in patients with acute paracetamol overdose and compared the results to patients with chronic cirrhosis and normal healthy controls. The results demonstrate that in paracetamol overdose coagulation factors (F)II, V, VII and X were reduced to a similar degree and were significantly lower than FIX and FXI (mean levels 0.28, 0.16, 0.13, 0.19, 0.51 and 0.72 IU mL−1, respectively). In cirrhosis, by contrast, FII, FV, FVII, FIX and FX were equally reduced whilst FXI was lower than the other factors (mean levels 0.64, 0.69, 0.62, 0.60, 0.66 and 0.40 IU mL−1, respectively). FVIII was raised in paracetamol overdose patients but normal in those with cirrhosis (mean levels 1.95 and 1.01 IU mL−1, respectively). Interleukin-6 and tumor necrosis factor-α levels were raised in both patient groups, but higher levels were found in paracetamol overdose, compared to cirrhosis. Thrombin-antithrombin and soluble tissue factor levels were higher in those with acute liver injury but normal in cirrhosis. Antithrombin levels were reduced in both acute liver injury and cirrhosis. From these data we put forward a novel mechanism for the coagulation changes in acute paracetamol induced liver injury. We propose that immune activation leads to tissue factor-initiated consumption of FII, FV, FVII and FX, but that levels of FIX and FXI are better preserved because antithrombin inhibits the thrombin induced positive feedback loop that activates these latter factors.  相似文献   
3.
4.
5.
A convenience sample of hospital workers, those receiving influenza vaccine and those not receiving vaccine, were asked to complete questionnaires delineating the occurrence of symptoms (e.g., fever, headache, extreme tiredness, dry cough, sore throat, runny nose, stuffy nose, muscle aches) and absenteeism in the 7-day period post-vaccination if vaccinated. Those unvaccinated completed the questionnaire in a self-selected 7 consecutive day period during the study conducted from November 2004 to February 2005. Those receiving either Fluzone or FluMist reported significantly fewer symptoms and related absenteeism than the unvaccinated group (p < .05). Administration of influenza vaccine did not result in higher rates of post-vaccination symptoms as compared to an unvaccinated group. Further, vaccinated employees did not experience higher absenteeism rates as a result of receiving either influenza vaccine. However, for those reporting absenteeism as a result of symptoms, mean absenteeism days were highest in the FluMist group (4.5 days) compared to the unvaccinated group (2.1 days) and the Fluzone group (1.9 days).  相似文献   
6.
7.
8.
Direct vascular injury after primary total knee arthroplasty is rare. This case report illustrates a 65-year-old female who was diagnosed with a pseudoaneurysm of the popliteal artery when she was investigated for increased leg swelling and pain 1 week after total knee arthroplasty. She had a percutaneous endovascular repair with a stent after thrombectomy.  相似文献   
9.
10.
Sixty children aged 5-13 years with moderately severe asthma took part in a double-blind, placebo-controlled trial of ketotifen. The design incorporated a 22 week study period, the addition of ketotifen or placebo to the current medication, and a controlled withdrawal of the regular therapy. Children receiving ketotifen showed significantly lower mean numbers of asthma attacks and less absence from school. The addition of ketotifen to existing treatment was associated with marginally significant changes in rates of day and night wheezing. In the second phase of study, additional therapy was withdrawn from both the ketotifen and placebo groups which resulted in a high (percentage) withdrawal. Children receiving ketotifen did not have a significantly lower failure rate than those given placebo.  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