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   25649篇
  免费   1798篇
  国内免费   169篇
耳鼻咽喉   206篇
儿科学   581篇
妇产科学   468篇
基础医学   3671篇
口腔科学   259篇
临床医学   2303篇
内科学   6022篇
皮肤病学   332篇
神经病学   2523篇
特种医学   867篇
外国民族医学   1篇
外科学   4768篇
综合类   160篇
一般理论   9篇
预防医学   1571篇
眼科学   292篇
药学   1551篇
中国医学   77篇
肿瘤学   1955篇
  2023年   112篇
  2022年   186篇
  2021年   490篇
  2020年   360篇
  2019年   595篇
  2018年   648篇
  2017年   492篇
  2016年   537篇
  2015年   630篇
  2014年   886篇
  2013年   1207篇
  2012年   1814篇
  2011年   1961篇
  2010年   1191篇
  2009年   1123篇
  2008年   1718篇
  2007年   1767篇
  2006年   1653篇
  2005年   1729篇
  2004年   1529篇
  2003年   1551篇
  2002年   1578篇
  2001年   227篇
  2000年   189篇
  1999年   258篇
  1998年   336篇
  1997年   320篇
  1996年   225篇
  1995年   217篇
  1994年   174篇
  1993年   171篇
  1992年   138篇
  1991年   119篇
  1990年   115篇
  1989年   88篇
  1988年   90篇
  1987年   70篇
  1986年   104篇
  1985年   88篇
  1984年   90篇
  1983年   94篇
  1982年   102篇
  1981年   90篇
  1980年   88篇
  1979年   59篇
  1978年   46篇
  1977年   38篇
  1976年   37篇
  1975年   36篇
  1974年   36篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Congenital dislocation of the hip (CDH) in an adult can accompany or cause mechanical low-back pain. This in turn, can create confusion in making the proper diagnosis. The mechanical alterations caused by CDH create an added strain to the lumbosacral spine. Manipulative treatment for back pain in these patients must not subject the dislocated hips to undue torque.  相似文献   
73.
Summary During an epidemiological survey on arc welders, serum copper and ceruloplasmin were determined in two groups of workers. One group consisted of aluminum welders who were divided into two groups: 13 welders working inside aluminum tanks (confined atmosphere) and 8 welders engaged in the production of vans for dump trucks (nonconfined atmosphere). The reference group consisted of 26 workers of the same plant who were not exposed to welding fumes. Ozone, the major pollutant in aluminum arc welding, was thought to be the principal factor in the significant decrease (P < 0.01) of mean ceruloplasmin in confined welders. This decrease in the level of ceruloplasmin was still within the reference values and was not linked to age or to tobacco consumption. We found a linear relationship between ceruloplasmin concentration and the cumulated worktime along the week. This effect could be a sign in the serum of a lung reaction against oxidant activity in this type occupational exposure.  相似文献   
74.
OBJECTIVE: Non-steroidal anti-inflammatory drugs (NSAIDs) are routinely used after coronary artery bypass surgery (CABG), yet their effects have seldom been evaluated in randomized controlled settings. The aim of this study was to examine the efficacy and safety of a commonly used NSAID, naproxen. We hypothesized that naproxen would reduce postoperative pain following CABG without increasing complications. METHODS: Patients (N=98) undergoing primary CABG were randomized to receive naproxen (500 mg q12hX5 doses via suppository started 1h after operation, followed by oral 250 mg q8hX6 doses) or placebo. Standard analgesic and anti-emetic regimens were available to both patient groups. Interventions were double-blinded. Primary end-points were postoperative pain measured before and after chest physiotherapy by visual analog scale and pulmonary slow vital capacity (SVC). RESULTS: Baseline characteristics were equivalent between the two groups. Over the first 4 postoperative days, naproxen decreased pain by 47+/-17% on average before chest physiotherapy (P=0.034), and 44+/-13% after chest physiotherapy (P=0.0092). Patients who received naproxen also had better preservation of SVC over the first 4 postoperative days (mean loss of SVC from baseline: 2.1+/-0.1 vs. 2.5+/-0.1l, naproxen vs. placebo, P=0.0032). This was concomitant with a lower white blood cell count observed in naproxen patients (9.2+/-0.3 vs. 12.7+/-1.5x10(9)/l, naproxen vs. placebo, P=0.03). Patients who received naproxen had more chest tube drainage after 4h postoperatively, but there was no difference in the incidence or amount of transfusions. There was no difference in medication use, length of stay, or in the incidence of atrial fibrillation, azotemia, and other complications. CONCLUSIONS: Naproxen is an effective and low-cost adjunct for optimization of pain control and lung recovery after CABG. Its use may result in increased chest tube drainage, but no apparent increase in other complications.  相似文献   
75.
76.
Did Ramesses II really have ankylosing spondylitis? A reappraisal.   总被引:1,自引:0,他引:1  
OBJECTIVE: To challenge the diagnosis of ankylosing spondylitis in the mummy of Ramesses II that was suggested about 30 years ago and to propose a differential diagnosis for the changes that were detected in the mummy's spine and pelvis. METHODS: We read and interpreted both the published and unpublished radiographs of the mummy. RESULTS: Changes in the mummy's spine and pelvis included ossification of the anterior longitudinal ligament at the cervical spine level, ossified enthesopathy of both the right and left rectus femoris tendons as well as the right ischial tuberosity, a large osteophyte at both acetabula margins, no ankylosis of the cervical apophyseal joints and no ankylosis of the right sacroiliac joint. CONCLUSION: The radiologic evidence does not support the claim that Ramesses II had ankylosing spondylitis. Our radiologic reappraisal suggests instead the diagnosis of diffuse idiopathic skeletal hyperostosis. This new diagnosis needs to be validated by a computed tomographic scan of the mummy.  相似文献   
77.
78.
Dopamine agonists have been recommended as early treatment for Parkinson's disease (PD), alone or combined with levodopa. Piribedil is a non-ergot selective D(2)/D(3) agonist with alpha(2) antagonist properties shown to be effective in the treatment of PD. This 12-month international, randomized, double-blind trial aimed to assess the efficacy of piribedil 150 mg versus bromocriptine 25 mg, in early combination with levodopa in Stage I to III PD patients. Motor efficacy was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS III, Items 18-31) as improvement from baseline. Response rate was defined as a 30% improvement. Among the 425 randomly assigned patients, 178 were also included in a substudy on cognitive follow-up evaluated by a dysexecutive syndrome oriented battery. A relevant improvement in UPDRS III over the 12-month study duration was observed both in the piribedil and bromocriptine groups (-7.9 +/- 9.7 points from baseline versus -8.0 +/- 9.5; not significant [n.s.]) with a response rate of 58.4% and 55.3% (n.s.), respectively. Piribedil and bromocriptine resulted in similar improvement on all UPDRS III subscores. Piribedil patients required less levodopa dose increase than those on bromocriptine. Cognitive performance remained generally unchanged in both groups, with a significant effect of piribedil limited to the Wisconsin Card Sorting Test. An overall good tolerability of piribedil was observed. Early combination of piribedil 150 mg with levodopa resulted in significant long-term improvement of all motor symptoms in PD patients insufficiently controlled by levodopa alone. Taking into account both efficacy and acceptability in the long-term, piribedil proved in this bromocriptine controlled study to be an effective and safe treatment for PD.  相似文献   
79.
The contribution of each monocular pathway to the timing of the binocular pattern visual evoked potential was assessed in situations where a significant interocular timing discrepancy was observed. Monocular and binocular pattern visual evoked potentials to 0.5° checks were recorded from normal subjects, normal subjects in whom one eye was blurred, patients with monocular amblyopia, and patients with resolved unilateral optic neuritis. Normal subjects showed facilitation, while suppression was evidenced in subjects with monocular blurring. In patients with amblyopia, the affected pathway had no effect on binocular pattern visual evoked potential latency, suggesting that the amblyopic eye was suppressed. In contrast, all patients with optic neuritis showed binocular averaging. Our results show that different forms of binocular interaction are evidenced in normal subjects, in amblyopia and in optic neuritis, and suggest that a comparative analysis of monocular and binocular pattern visual evoked potential peak times brings valuable information to the clinical evaluation that could be used to distinguish disease processes further.Abbreviation BPVEP binocular pattern visual evoked potential  相似文献   
80.
We conducted a case-control study of mental retardation (MR) in which case children (aged 10 years) were identified from existing records at multiple sources, primarily the public school systems. Control children were drawn from a roster of public school students not receiving special education services. We found that maternal educational level at the time of delivery was strongly and inversely related to a form of MR not accompanied by other serious neurologic conditions. For this isolated form of MR, maternal educational level was by far the most important predictor from among seven sociodemographic variables examined. There was a significant race-education interaction that indicated a steeper gradient in risk among white mothers than among black mothers. Relative to children of white mothers with 12 years of education, all children of black mothers, except those whose mothers had 16 or more years of education, were at increased risk. The results may be useful as a guide for selecting high-risk groups as candidates for early childhood intervention programs.  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