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   3163594篇
  免费   248854篇
  国内免费   5658篇
耳鼻咽喉   45845篇
儿科学   101716篇
妇产科学   85333篇
基础医学   447049篇
口腔科学   90144篇
临床医学   287875篇
内科学   615546篇
皮肤病学   65854篇
神经病学   261194篇
特种医学   125908篇
外国民族医学   1304篇
外科学   477690篇
综合类   74327篇
现状与发展   2篇
一般理论   1250篇
预防医学   254070篇
眼科学   73922篇
药学   236655篇
  6篇
中国医学   6020篇
肿瘤学   166396篇
  2018年   32668篇
  2017年   24994篇
  2016年   27566篇
  2015年   31162篇
  2014年   44545篇
  2013年   67904篇
  2012年   92268篇
  2011年   97624篇
  2010年   57688篇
  2009年   55069篇
  2008年   92743篇
  2007年   98865篇
  2006年   99543篇
  2005年   96858篇
  2004年   93684篇
  2003年   90649篇
  2002年   89137篇
  2001年   146250篇
  2000年   151437篇
  1999年   128386篇
  1998年   37226篇
  1997年   33730篇
  1996年   33607篇
  1995年   32399篇
  1994年   30358篇
  1993年   28362篇
  1992年   103276篇
  1991年   100344篇
  1990年   96947篇
  1989年   93354篇
  1988年   86443篇
  1987年   85180篇
  1986年   80401篇
  1985年   76919篇
  1984年   58361篇
  1983年   49646篇
  1982年   29906篇
  1981年   26832篇
  1979年   54368篇
  1978年   38077篇
  1977年   32210篇
  1976年   30277篇
  1975年   32171篇
  1974年   39213篇
  1973年   37376篇
  1972年   34843篇
  1971年   32073篇
  1970年   30367篇
  1969年   28094篇
  1968年   25583篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
72.
73.
OBJECTIVE: To explore the presence and grade of denervation in three mimic muscles in facial nerve palsy. METHODS: The frontalis, orbicularis oculi (OO), and mentalis muscles were explored in 54 patients with Bell's palsy, after 30 days from the beginning of symptoms. Concentric needle electromyography, including fibrillation detection, was performed in the three muscles on the affected side. Compound muscle action potentials (CMAP) were recorded on both sides and a CMAP ratio was calculated from each muscle. The House-Brackman scale was used to assess the initial clinical evaluation and the follow-up until recovery. RESULTS: Fibrillation was recorded in 32 patients on the 30th day after the onset and was present in 100% of mentalis and in 90% of frontalis, but in only 34% of OO, a statistically significant difference. The grade of fibrillation in OO was also statistically lower from those in the other two muscles. The 32 patients were grouped according to the presence (A) or not (B) of fibrillation in OO. In group A, CMAP ratios (affected/normal side) did not differ significantly among the three muscles. However, in group B they were significantly greater in OO and frontalis than in mentalis. In between-group comparison, group B muscles had significantly higher CMAP ratios, lower degree of fibrillation, and better functional recovery. CONCLUSION: In facial palsy, the presence and grade of fibrillation in OO are lower than in frontalis and mentalis muscles and prognosis is more favorable for the non-fibrillating OO group of patients.  相似文献   
74.
Although studies have documented underuse of controller medications and overuse of short-acting inhaled ss(2)-agonist among children with persistent asthma in disadvantaged communities, the persistence of oral ss(2)-agonist use in pediatric practice has not been studied since inhaled short-acting ss(2)-agonists became widespread. We describe medications used to treat asthma among children 3 to 5 years of age at 10 Head Start and other subsidized preschool centers in East and Central Harlem, New York City. We interviewed 149 parents/guardians of children who were identified as having probable asthma based on physician's diagnosis, persistent symptoms, hospitalization, and medication use. We classified 86 of the 149 children (58%) as having current persistent asthma. Only 15 of them (17%) were reported to have used controller medications at least 5 days/week in the last 4 weeks-only 2 of whom used inhaled corticosteroids. By contrast, 53 children (62%) used oral ss(2)-agonist in the last 4 weeks, often (72%) in conjunction with nebulized or inhaled short-acting ss(2)-agonist. Use of oral ss(2)-agonist was associated with more severe symptoms. This study documents the continued widespread use of oral ss(2)-agonist for treatment of children in a low-income community with high prevalence of asthma.  相似文献   
75.
OBJECTIVES: To evaluate a novel method for localization of subdural electrodes in presurgical assessment of patients with drug-resistant focal epilepsy. METHODS: We studied eight consecutive patients with posterior epilepsy in whom subdural electrodes were implanted for presurgical evaluation. Electrodes were detected on post-implantation brain CT scans through a semiautomated procedure based on a MATLAB routine. Then, post-implantation CT scans were fused with pre-implantation MRI to localize the electrodes in relation to the underlying cortical structures. The reliability of this procedure was tested by comparing 3D-rendered MR images of the electrodes with electrode position as determined by intraoperative digital photography. RESULTS: In each patient, all electrodes could be correctly localized and visualized in a stereotactic space, thus allowing optimal surgery planning. The agreement between the procedure-generated images and the digital photographs was good according to two independent raters. The mean mismatch between the 3D images and the photographs was 2 mm. CONCLUSIONS: While our findings need confirmation on larger samples including patients with anterior epilepsy, this procedure allowed to localize subdural electrodes and to establish the spatial relationship of each electrode to the underlying brain structure, either normal or damaged, on brain convessity, basal and medial cortex. SIGNIFICANCE: Being simple, rapid, unexpensive, and reliable, this procedure holds promise to be useful to optimize epilepsy surgery planning.  相似文献   
76.
77.
78.
79.
80.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease.  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