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   411565篇
  免费   21273篇
  国内免费   14394篇
耳鼻咽喉   3288篇
儿科学   9530篇
妇产科学   7811篇
基础医学   44080篇
口腔科学   5725篇
临床医学   42863篇
内科学   69590篇
皮肤病学   3456篇
神经病学   29496篇
特种医学   17283篇
外国民族医学   96篇
外科学   54666篇
综合类   35999篇
现状与发展   48篇
一般理论   45篇
预防医学   32777篇
眼科学   9356篇
药学   33268篇
  164篇
中国医学   11460篇
肿瘤学   36231篇
  2024年   710篇
  2023年   3491篇
  2022年   8681篇
  2021年   11424篇
  2020年   8395篇
  2019年   7601篇
  2018年   29127篇
  2017年   23751篇
  2016年   25563篇
  2015年   10933篇
  2014年   13437篇
  2013年   12582篇
  2012年   24193篇
  2011年   39525篇
  2010年   29938篇
  2009年   20536篇
  2008年   31731篇
  2007年   33981篇
  2006年   12809篇
  2005年   14496篇
  2004年   11804篇
  2003年   11818篇
  2002年   8988篇
  2001年   6237篇
  2000年   6497篇
  1999年   6556篇
  1998年   3839篇
  1997年   3864篇
  1996年   2873篇
  1995年   2676篇
  1994年   2322篇
  1993年   1551篇
  1992年   2322篇
  1991年   2075篇
  1990年   1784篇
  1989年   1527篇
  1988年   1314篇
  1987年   1213篇
  1986年   962篇
  1985年   776篇
  1984年   509篇
  1983年   401篇
  1982年   249篇
  1981年   201篇
  1980年   230篇
  1979年   245篇
  1978年   149篇
  1977年   115篇
  1976年   105篇
  1974年   135篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
31.
Bradyarrhythmia requiring permanent pacing after heart transplantation remains a common problem. Sinus node dysfunction is the most common indication, and late onset of atrioventricular (AV) block has rarely been reported. We report the case of a patient who developed advanced AV block at 41 months after transplantation. Right bundle branch block with progressive increase of QRS complex duration was noted in serial electrocardiograms. At the time of late AV block development, the patient did not have acute rejection and coronary angiogram was normal. The mechanism of late onset of AV block is unclear, but it may be caused by progressive conduction.  相似文献   
32.
33.
34.

Background  

Health service policy in the United Kingdom emphasises the importance of self-care by patients with chronic conditions. Written information for patients about their condition is seen as an important aid to help patients look after themselves. From a discourse analysis perspective written texts such as patient information leaflets do not simply describe the reality of a medical condition and its management but by drawing on some sorts of knowledge and evidence rather than others help construct the reality of that condition. This study explored patient information leaflets on osteoarthritis (OA) to see how OA was constructed and to consider the implications for self-care.  相似文献   
35.
In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR < T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished.  相似文献   
36.

Background  

Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure.  相似文献   
37.

Background  

Skin and soft tissue infections are increasingly prevalent clinical problems, and it is important for health care practitioners to be well trained in how to treat skin abscesses. A realistic model of abscess incision and drainage will allow trainees to learn and practice this basic physician procedure.  相似文献   
38.
Abstract Background: Primary shoulder hemiarthroplasty is an established treatment modality for complex fractures of the proximal humerus. Long-term functional outcome is often disappointing. However, little is known about social implications particularly in the elderly. Methods: A single-institution case series of consecutive geriatric patients (age > 70 years) treated with shoulder hemiarthroplasty for complex fractures of the proximal humerus between 1994 and 1997 was analysed. Postoperative morbidity, long-term function, radiological outcome and social implications were evaluated. Results: Seventy-seven patients fulfilled the study criteria. Median age at the time of operation was 80 years (range 70–93 years). Systemic and local postoperative complications were observed in 8% including 2 patients (3%) with revision surgery. Postoperative mortality was 1%. Forty-eight patients (62%) were available for follow-up (median 49 months, range 25–80 months), 22 (29%) died from causes unrelated to hemiarthroplasty before follow-up and 7 patients (9%) did not attend follow-up examination. Median Constant-Murley score was 41 points (range 17–77 points). Long-term results concerning pain were satisfying. The Oxford shoulder score ranged from 14 to 40 (median 30). Forty-one patients (85%) still lived in their original environment and managed their daily life independently despite poor shoulder function. Four patients (8%) lived in a retirement home and 3 (6%) in a nursery home. Eighty percent of our patients were still able to use public transportation, do the daily shopping and wash their whole body by themselves. Conclusion: Most patients managed their daily life independently despite poor shoulder function.  相似文献   
39.
Purpose Post operative monitoring is crucial for the success of microsurgical free tissue transfer. Sophisticated and expensive methods are available for monitoring. We propose a novel technique using digital photography and the internet as a reliable and cost effective method to monitor free tissue transfers. Methods 163 micro‐vascular procedures were monitored using this technique over 8 months. Serial photographs taken to show flap color. Capillary refill time, pin prick‐ bleed time and color and hand held Doppler signal was recorded in the movie mode of a standard 5 mega pixel camera with duration of 15 seconds. Data was sent to the surgeon at regular intervals and or as deemed necessary. Results Analysis of the 67 cases is presented. 5 re‐explorations were done. The early diagnosis of venous congestion was possible using this technique. Timely intervention contributed to the success of the re‐explorations and these flaps could be salvaged. The file size of images was in the range of 1 MB–6 MB. The file size of an entire set of images ranged about 7 MB–9 MB. These were sent across the ADSL internet lines. Conclusion The use of the digital images and the internet allow reconstructive surgeons to have a reliable picture of the state of their free tissue transfers. This permits decrease in observer error and saves valuable time which otherwise needs to be spent to verify situations of doubt and offers an ideal solution to the logistic problem of having to visit the patient in case of doubt.  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