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   60164篇
  免费   3109篇
  国内免费   503篇
耳鼻咽喉   587篇
儿科学   1141篇
妇产科学   1852篇
基础医学   7079篇
口腔科学   2127篇
临床医学   4687篇
内科学   16326篇
皮肤病学   1204篇
神经病学   5594篇
特种医学   1850篇
外科学   9143篇
综合类   216篇
一般理论   10篇
预防医学   2957篇
眼科学   1006篇
药学   3344篇
中国医学   138篇
肿瘤学   4515篇
  2024年   42篇
  2023年   453篇
  2022年   895篇
  2021年   1989篇
  2020年   1136篇
  2019年   1557篇
  2018年   2095篇
  2017年   1383篇
  2016年   1563篇
  2015年   1815篇
  2014年   2484篇
  2013年   3176篇
  2012年   4864篇
  2011年   4794篇
  2010年   2697篇
  2009年   2384篇
  2008年   4021篇
  2007年   4129篇
  2006年   3890篇
  2005年   3777篇
  2004年   3437篇
  2003年   3059篇
  2002年   2669篇
  2001年   417篇
  2000年   343篇
  1999年   445篇
  1998年   506篇
  1997年   429篇
  1996年   387篇
  1995年   373篇
  1994年   285篇
  1993年   218篇
  1992年   227篇
  1991年   184篇
  1990年   151篇
  1989年   134篇
  1988年   104篇
  1987年   98篇
  1986年   111篇
  1985年   100篇
  1984年   107篇
  1983年   95篇
  1982年   120篇
  1981年   83篇
  1980年   79篇
  1979年   45篇
  1978年   53篇
  1977年   41篇
  1976年   42篇
  1974年   34篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
With easy chemical synthesis from its precursor, methamphetamine (MA) is now widespread in many countries. The abuse of methamphetamine is associated with several negative effects on health, because MA is a neurotoxin and a dangerous central nervous system stimulant. It changes levels of neurotransmitters in the brain, releasing dopamine and inhibiting nor epinephrine uptake which increases sympathetic nervous system activity and can lead to cardiac arrhythmia, hypertension and tachypnea. The consequences of MA abuse are clearly manifested in oral diseases (like “meth mouth”) which is characterised by extensive caries, teeth grinding with ensuing dental wear and trismus. The present review was designed to fill the gap in knowledge about methamphetamine abuse in the European Union (EU) and to illustrate the main clinical effects of prolonged use. After describing the pharmacology and systemic effects of methamphetamine and concentrating on its effects on the mouth, the present review compares the epidemiology and incidence of abuse in the world, particularly the USA and the EU. Key words:Methamphetamine, “Meth mouth”, drug abuse, oral health.  相似文献   
4.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
5.
6.
7.
8.
9.
10.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.  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