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   18035篇
  免费   1419篇
  国内免费   55篇
耳鼻咽喉   192篇
儿科学   418篇
妇产科学   395篇
基础医学   2335篇
口腔科学   838篇
临床医学   1723篇
内科学   4518篇
皮肤病学   338篇
神经病学   1706篇
特种医学   591篇
外科学   2300篇
综合类   98篇
一般理论   5篇
预防医学   1536篇
眼科学   275篇
药学   1073篇
中国医学   45篇
肿瘤学   1123篇
  2023年   88篇
  2022年   254篇
  2021年   503篇
  2020年   316篇
  2019年   519篇
  2018年   653篇
  2017年   452篇
  2016年   479篇
  2015年   522篇
  2014年   713篇
  2013年   850篇
  2012年   1257篇
  2011年   1248篇
  2010年   810篇
  2009年   653篇
  2008年   980篇
  2007年   1041篇
  2006年   943篇
  2005年   892篇
  2004年   774篇
  2003年   696篇
  2002年   615篇
  2001年   368篇
  2000年   332篇
  1999年   367篇
  1998年   158篇
  1997年   154篇
  1996年   119篇
  1995年   119篇
  1994年   109篇
  1993年   95篇
  1992年   232篇
  1991年   214篇
  1990年   182篇
  1989年   202篇
  1988年   172篇
  1987年   149篇
  1986年   157篇
  1985年   155篇
  1984年   109篇
  1983年   90篇
  1982年   51篇
  1981年   60篇
  1979年   73篇
  1978年   59篇
  1976年   45篇
  1975年   50篇
  1974年   40篇
  1973年   54篇
  1972年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
In every Radiation Oncology Department there is a group of patients referred for curative radiotherapy and within this group of patients there is a subset of patients who present the most difficult of treatment scenarios, maximum tumor dose and minimum spinal cord dose. The case to be presented involved the use of a head and neck five field technique of which three fields were treated isocentrically with the remaining two fields being electron boosts. It is from these patients that we extend to the maximum our planning capabilities.  相似文献   
32.
The present study provides an analysis of the effects of particular patterns of teacher respose to students' entries in dialogue journals. It extended on previous research related to teacher-student instructional discourse by concentrating on written, teacher-student interactions. Second grade children who were participating in a daily dialogue journal activity were randomly subjected to two types of response patterns by their teacher. The results show that a teacher's elaborative responses to student journal entries directly lead to increase written output by students coupled with a distinct process #ophigher order#cp orientation of student entries.  相似文献   
33.
Ciclesonide is an onsite-activated inhaled corticosteroid (ICS) for the treatment of asthma. This study compared the efficacy, safety and effect on quality of life (QOL) of ciclesonide 160 microg (ex-actuator; nominal dose 200 microg) vs. budesonide 400 microg (nominal dose) in children with asthma. Six hundred and twenty-one children (aged 6-11 yr) with asthma were randomized to receive ciclesonide 160 microg (ex-actuator) once daily (via hydrofluoroalkane metered-dose inhaler and AeroChamber Plus spacer) or budesonide 400 microg once daily (via Turbohaler) both given in the evening for 12 wk. The primary efficacy end-point was change in forced expiratory volume in 1 s (FEV1). Additional measurements included change in daily peak expiratory flow (PEF), change in asthma symptom score sum, change in use of rescue medication, paediatric and caregiver asthma QOL questionnaire [PAQLQ(S) and PACQLQ, respectively] scores, change in body height assessed by stadiometry, change in 24-h urinary cortisol adjusted for creatinine and adverse events. Both ciclesonide and budesonide increased FEV1, morning PEF and PAQLQ(S) and PACQLQ scores, and improved asthma symptom score sums and the need for rescue medication after 12 wk vs. baseline. The non-inferiority of ciclesonide vs. budesonide was demonstrated for the change in FEV1 (95% confidence interval: -75, 10 ml, p = 0.0009, one-sided non-inferiority, per-protocol). In addition, ciclesonide and budesonide showed similar efficacy in improving asthma symptoms, morning PEF, use of rescue medication and QOL. Ciclesonide was superior to budesonide with regard to increases in body height (p = 0.003, two-sided). The effect on the hypothalamic-pituitary-adrenal axis was significantly different in favor of ciclesonide treatment (p < 0.001, one-sided). Both ciclesonide and budesonide were well tolerated. Ciclesonide 160 microg once daily and budesonide 400 microg once daily were effective in children with asthma. In addition, in children treated with ciclesonide there was significantly less reduction in body height and suppression of 24-h urinary cortisol excretion compared with children treated with budesonide after 12 wk.  相似文献   
34.
35.
36.
37.
5H-Mebendazole and some related heterocyclic methyl carbamates were synthesized and their anthelmintic activity against Caenorhabditis elegans was determined. In order to study the influence of the heteroaromatic region with regard to the carbamate moiety on biological activity, the molecular electrostatic potentials (MEP) of all structures were calculated and a structure-activity relationship (SAR) was established. The electrostatic pattern of activity includes two minima of the carbamate moiety, a third heterocyclic minimum, and a pi-electronic region.  相似文献   
38.
39.
Apical ballooning is a novel clinical entity reported in different contexts of physical and psychological stress, which is more common in middle-aged women. Of unknown etiology, the syndrome is characterized by a sudden and transient dilatation of the left ventricular apex in the absence of obstructive atherosclerotic coronary disease or evidence of myocardial necrosis, with total late recovery of ventricular function. The authors report the case of a 53-year-old woman who was admitted to the emergency room with left arm ischemia and low cardiac output, requiring ventilatory support. Left catheterization showed typical medial and apical myocardial dysfunction, with normal coronary arteries. Transesophageal echocardiography revealed a thrombus attached to the lower face of the aortic arch, which probably explained the thromboembolism of the arm but was unlikely to be the cause of the left ventricular dysfunction since there were no enzymatic or electrocardiographic signs of myocardial necrosis and normal wall motion was fully recovered.  相似文献   
40.
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