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   275003篇
  免费   12958篇
  国内免费   754篇
耳鼻咽喉   3490篇
儿科学   8045篇
妇产科学   5910篇
基础医学   38502篇
口腔科学   7086篇
临床医学   21537篇
内科学   63065篇
皮肤病学   7057篇
神经病学   24557篇
特种医学   8146篇
外国民族医学   101篇
外科学   35084篇
综合类   1122篇
一般理论   70篇
预防医学   23465篇
眼科学   5255篇
药学   18764篇
中国医学   807篇
肿瘤学   16652篇
  2023年   1544篇
  2022年   1672篇
  2021年   4854篇
  2020年   2811篇
  2019年   4910篇
  2018年   8762篇
  2017年   5739篇
  2016年   5872篇
  2015年   6642篇
  2014年   7379篇
  2013年   11429篇
  2012年   19236篇
  2011年   19143篇
  2010年   9768篇
  2009年   7620篇
  2008年   16411篇
  2007年   17479篇
  2006年   16112篇
  2005年   15969篇
  2004年   14864篇
  2003年   13518篇
  2002年   12713篇
  2001年   6408篇
  2000年   6406篇
  1999年   5824篇
  1998年   1256篇
  1997年   1065篇
  1996年   991篇
  1995年   920篇
  1992年   3341篇
  1991年   2974篇
  1990年   2842篇
  1989年   2581篇
  1988年   2429篇
  1987年   2256篇
  1986年   2163篇
  1985年   1956篇
  1984年   1468篇
  1983年   1254篇
  1979年   1244篇
  1978年   892篇
  1977年   833篇
  1975年   831篇
  1974年   1014篇
  1973年   1019篇
  1972年   943篇
  1971年   931篇
  1970年   867篇
  1969年   916篇
  1968年   801篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
Gastrogastric fistula: a possible complication of Roux-en-Y gastric bypass.   总被引:4,自引:0,他引:4  
BACKGROUND: Gastrogastric fistula is a communication between the proximal gastric pouch and the distal gastric remnant, rarely described in the realm of bariatric procedures. The aim of this study was to review the existing literature about this topic and to demonstrate its laparoscopic treatment. METHODS: An extensive literature review found several articles reporting this complication. However, no citation was found describing the steps of the laparoscopic management of this situation. RESULTS: Gastrogastric fistula occurs in up to 6% of Roux-en-Y gastric bypasses. Two theories exist for fistula formation: (1) it is a technical complication derived from the incomplete division of the stomach during the creation of the pouch, and (2) it occurs after a staple-line failure, developing a leak with an abscess, which then drains into the distal stomach forming the fistula. Early symptoms include fever, tachycardia, and abdominal pain. Failure in weight loss is a late clinical sign observed in these patients. Diagnosis is based on radiologic study, upper endoscopy and computed tomography. When identified in the acute postoperative course, laparoscopic treatment is easy. Chronic fistulas are difficult to manage, and the laparoscopic approach is an alternative to open surgery. CONCLUSIONS: Gastrogastric fistula is a possible complication of Roux-en-Y gastric bypass and its laparoscopic treatment is feasible.  相似文献   
113.
In brain regions containing noradrenergic (NA) cell bodies or terminals, DSP-4 induces changes in the activity of catecholamine-synthesizing enzymes which suggest that central NA neurons are lesioned by this neurotoxin. In contrast, the lack of change in the same enzymatic activities in an area containing mostly adrenergic (A) neurons (C2 region), favors the hypothesis of a resistance of the A neurons to DSP-4. Furthermore, the enzymatic changes observed in peripheral organs suggest a peripheral activation of the NA cell bodies in response to lesioning of the sympathetic terminals by DSP-4.  相似文献   
114.

Introduction  

Planning human resources for health (HRH) is a complex process for policy-makers and, as a result, many countries worldwide swing from surplus to shortage. In-depth case studies can help appraising the challenges encountered and the solutions implemented. This paper has two objectives: to identify the key challenges in HRH planning in Belgium and to formulate recommendations for an effective HRH planning, on the basis of the Belgian case study and lessons drawn from an international benchmarking.  相似文献   
115.

Objective  

The aim of the project was to assess the effectiveness and safety of weekly epoetin-beta (EB) in patients with gastrointestinal cancer (GIC) subjected to concomitant chemoradiotherapy (CCTRT).  相似文献   
116.
Hypoxia is related to poor prognosis because it is associated to chemo-and radioresistance. During recent years the evolution of imaging methods like PET/CT and MRI has meant the appearance of new perspectives with direct implications in radiation therapy. We discuss previous experiences in staging, planning and in the follow-up process with these techniques for measuring tumour hypoxia.  相似文献   
117.
118.
119.
Introduction and objectiveWhen sleep apnea-hypopnea syndrome (SAHS) and cardiovascular disease occur concurrently, prognosis is affected. Echocardiography can detect structural cardiac abnormalities but using this technique in all patients would place a heavy burden on resources. The objective of this study was to investigate whether the N-terminal fraction of brain natriuretic peptide (NT-proBNP) can be used as a marker for silent heart disease.Patients and methodsNT-proBNP concentration was measured in the 114 consecutive patients with SAHS who underwent echocardiography before starting treatment. Left and right ventricular systolic and diastolic function, as well as structural abnormalities, were studied. Correlations between NT-proBNP concentration and the abnormalities detected were investigated. A receiver operating characteristics (ROC) curve was plotted for NT-proBNP concentration and cardiac abnormalities.ResultsData for 98 patients were finally analyzed. NT-proBNP concentration was significantly correlated with ventricular septal thickness (r=0.63), posterior wall thickness (r=0.45), and left ventricular enddiastolic diameter (r=0.51) (P<.0001 for all correlations). The area under the ROC curve was significant (0.870; 95% confidence interval, 0.801-0.939; P<.0001). Assuming that specificity would be more useful for clinical practice, we calculated that NT-proBNP concentrations below 100 and 200 pg/mL could rule out structural abnormalities with a reliability of 90% and 100%, respectively.ConclusionsNT-proBNP concentration was strongly correlated with echocardiographic abnormalities and so could be a useful tool for identifying patients who should be referred to the cardiologist.  相似文献   
120.
Surgical procedures for the mammary region currently are assuming an important role in body-contouring surgery. Enhancement of results is a constant challenge to the plastic surgeon. A simple and efficient maneuver for resection of the breast’s lateral pole based on the mammoplasty technique of Professor Ivo Pitanguy is described. This study realized at the Private Clinic Sérgio Carreir?o, Rio de Janeiro, RJ, Brazil.  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