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   3820篇
  免费   244篇
  国内免费   14篇
耳鼻咽喉   83篇
儿科学   220篇
妇产科学   43篇
基础医学   471篇
口腔科学   86篇
临床医学   239篇
内科学   773篇
皮肤病学   46篇
神经病学   300篇
特种医学   167篇
外科学   621篇
综合类   56篇
一般理论   1篇
预防医学   162篇
眼科学   100篇
药学   389篇
中国医学   17篇
肿瘤学   304篇
  2023年   24篇
  2022年   71篇
  2021年   139篇
  2020年   67篇
  2019年   129篇
  2018年   139篇
  2017年   92篇
  2016年   95篇
  2015年   119篇
  2014年   150篇
  2013年   228篇
  2012年   289篇
  2011年   274篇
  2010年   166篇
  2009年   126篇
  2008年   159篇
  2007年   182篇
  2006年   193篇
  2005年   149篇
  2004年   147篇
  2003年   143篇
  2002年   118篇
  2001年   84篇
  2000年   80篇
  1999年   52篇
  1998年   37篇
  1997年   17篇
  1996年   24篇
  1995年   18篇
  1993年   12篇
  1992年   40篇
  1991年   52篇
  1990年   47篇
  1989年   34篇
  1988年   30篇
  1987年   25篇
  1986年   26篇
  1985年   26篇
  1984年   19篇
  1983年   19篇
  1982年   11篇
  1981年   15篇
  1980年   14篇
  1979年   22篇
  1978年   12篇
  1977年   13篇
  1976年   14篇
  1974年   16篇
  1973年   14篇
  1971年   17篇
排序方式: 共有4078条查询结果,搜索用时 250 毫秒
91.
Seventy-eight patients undergoing mitral valve surgery with or without replacement of the aortic valve also underwent procedures on the tricuspid valve over a period of 10 years. All patients were in functional class III or IV preoperatively. The procedures were performed in all patients with organic disease of the tricuspid valve (N = 44) and in those with moderate or severe functional tricuspid valvar regurgitation (N = 34). Seventy-one patients underwent DeVega's annuloplasty with or without commissurotomy. The overall mortality was 11.5%. 65 long-term survivors were followed up for a period of 6 months to 10 years (mean 5.3 years). Sixty-three patients were in functional class I or II at the last follow-up. Six patients had clinical evidence of mild to moderate tricuspid regurgitation. Regression of cardiomegaly (as judged by the chest radiograph and right ventricular hypertrophy seen in the electrocardiogram) was evident in most cases. Fifty-one of 54 patients evaluated by cross-sectional echocardiography were reported to have a functionally normal tricuspid valve. Doppler echocardiography in 28 patients showed no significant tricuspid regurgitation or stenosis in 26 patients. Eleven consecutive patients undergoing DeVega's annuloplasty were studied prospectively with pre- and postoperative Doppler echocardiography. Good correlation existed between right ventricular systolic pressures predicted by Doppler with those obtained preoperatively at cardiac catheterization. Postoperative Doppler echocardiography in these 11 patients showed complete restoration of competence of the tricuspid valve as well as normalisation of the right ventricular systolic pressure in 10 patients.  相似文献   
92.
93.
94.
95.
96.

Background

Shoulder balance for adolescent idiopathic scoliosis (AIS) patients is associated with patient satisfaction and self-image. However, few validated systems exist for selecting the upper instrumented vertebra (UIV) post-surgical shoulder balance.

Questions/Purposes

The purpose is to examine the existing UIV selection criteria and correlate with post-surgical shoulder balance in AIS patients.

Methods

Patients who underwent spinal fusion at age 10–18 years for AIS over a 6-year period were reviewed. All patients with a minimum of 1-year radiographic follow-up were included. Imbalance was determined to be radiographic shoulder height |RSH| ≥ 15 mm at latest follow-up. Three UIV selection methods were considered: Lenke, Ilharreborde, and Trobisch. A recommended UIV was determined using each method from pre-surgical radiographs. The recommended UIV for each method was compared to the actual UIV instrumented for all three methods; concordance between these levels was defined as “Correct” UIV selection, and discordance was defined as “Incorrect” selection.

Results

One hundred seventy-one patients were included with 2.3 ± 1.1 year follow-up. For all methods, “Correct” UIV selection resulted in more shoulder imbalance than “Incorrect” UIV selection. Overall shoulder imbalance incidence was improved from 31.0% (53/171) to 15.2% (26/171). New shoulder imbalance incidence for patients with previously level shoulders was 8.8%.

Conclusions

We could not identify a set of UIV selection criteria that accurately predicted post-surgical shoulder balance. Further validated measures are needed in this area. The complexity of proximal thoracic curve correction is underscored in a case example, where shoulder imbalance occurred despite “Correct” UIV selection by all methods.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-015-9451-y) contains supplementary material, which is available to authorized users.  相似文献   
97.

Background  

Studies from developed countries have reported on host-related risk factors for extra-pulmonary tuberculosis (EPTB). However, similar studies from high-burden countries like Nepal are lacking. Therefore, we carried out this study to compare demographic, life-style and clinical characteristics between EPTB and PTB patients.  相似文献   
98.
This article is a continuation of our previously published annual reviews of transcatheter aortic valve replacement (TAVR). In 2017, TAVR further established a foothold in the management of intermediate risk patients with the publication of SURTAVI trial. Randomized trials also addressed the use of cerebral protection during TAVR and single versus dual antiplatelet therapy after TAVR. Newer generation valve systems continued to be studied for their efficacy and safety. This paper summarizes the major studies published in 2017.
  相似文献   
99.
Lithium still retains its critical position in the treatment of bipolar disorder by virtue of its ability to prevent suicidal tendencies. However, chronic use of lithium is often limited by the development of nephrogenic diabetes insipidus (NDI), a debilitating condition. Lithium‐induced NDI is due to resistance of the kidney to arginine vasopressin (AVP), leading to polyuria, natriuresis and kaliuresis. Purinergic signalling mediated by extracellular nucleotides (ATP/UTP), acting via P2Y receptors, opposes the action of AVP on renal collecting duct (CD) by decreasing the cellular cAMP and thus AQP2 protein levels. Taking a cue from this phenomenon, we discovered the potential involvement of ATP/UTP‐activated P2Y2 receptor in lithium‐induced NDI in rats and showed that P2Y2 receptor knockout mice are significantly resistant to Li‐induced polyuria, natriuresis and kaliuresis. Extension of these studies revealed that ADP‐activated P2Y12 receptor is expressed in the kidney, and its irreversible blockade by the administration of clopidogrel bisulphate (Plavix®) ameliorates Li‐induced NDI in rodents. Parallel in vitro studies showed that P2Y12 receptor blockade by the reversible antagonist PSB‐0739 sensitizes CD to the action of AVP. Thus, our studies unravelled the potential beneficial effects of targeting P2Y2 or P2Y12 receptors to counter AVP resistance in lithium‐induced NDI. If established in further studies, our findings may pave the way for the development of better and safer methods for the treatment of NDI by bringing a paradigm shift in the approach from the current therapies that predominantly counter the anti‐AVP effects to those that enhance the sensitivity of the kidney to AVP action.  相似文献   
100.
Ossifying fibroma is a benign neoplasm of the bone, usually involving the posterior tooth bearing area of the mandible, predominantly seen in females in 2nd–4th decade of life with 5:1 prediliction. Fibro-osseous lesions other than FD seem to arise from the periodontal membrane. These lesions are usually asymptomatic, well defined clinically and radiologically amenable for enucleation. Fibro-osseous lesions of the jaws, including Juvenile Ossifying Fibroma (JOF), pose diagnostic and therapeutic difficulties due to their clinical, radiological and histological variability. Ossifying fibromas which appear as fast growing mass between 5 and 15 years of age, radiologically well bordered, and consistent with ossifying fibroma histologically, are referred as juvenile (aggressive) ossifying fibroma. We report a case of JOF of left side of the maxilla in an 11 year old girl which is an uncommon site of occurrence.  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