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   1400164篇
  免费   110862篇
  国内免费   8542篇
耳鼻咽喉   19589篇
儿科学   46224篇
妇产科学   37783篇
基础医学   194843篇
口腔科学   36140篇
临床医学   126776篇
内科学   277280篇
皮肤病学   29547篇
神经病学   106419篇
特种医学   55189篇
外国民族医学   700篇
外科学   209011篇
综合类   46195篇
现状与发展   21篇
一般理论   394篇
预防医学   104871篇
眼科学   31249篇
药学   107849篇
  116篇
中国医学   8912篇
肿瘤学   80460篇
  2021年   13302篇
  2019年   12666篇
  2018年   16961篇
  2017年   13586篇
  2016年   14126篇
  2015年   17488篇
  2014年   23739篇
  2013年   32971篇
  2012年   45856篇
  2011年   48649篇
  2010年   30130篇
  2009年   27811篇
  2008年   44197篇
  2007年   46742篇
  2006年   46597篇
  2005年   44946篇
  2004年   42245篇
  2003年   40691篇
  2002年   39317篇
  2001年   66659篇
  2000年   68942篇
  1999年   58746篇
  1998年   16363篇
  1997年   14926篇
  1996年   15139篇
  1995年   14355篇
  1994年   13617篇
  1993年   12270篇
  1992年   45307篇
  1991年   44148篇
  1990年   42788篇
  1989年   40596篇
  1988年   37339篇
  1987年   36628篇
  1986年   33909篇
  1985年   32527篇
  1984年   24290篇
  1983年   20403篇
  1982年   11802篇
  1981年   10776篇
  1979年   21447篇
  1978年   14918篇
  1977年   12595篇
  1976年   11743篇
  1975年   12663篇
  1974年   14732篇
  1973年   14178篇
  1972年   13017篇
  1971年   11766篇
  1970年   11085篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Although lesions of the pterygopalatine space are uncommon, there are instances in which this relatively inaccessible region must be entered for biopsy or excision of masses. Traditional open approaches to the pterygopalatine space, involving external or intraoral incisions, provide limited visualization and carry associated morbidities. The evolution and advancement of endoscopic sinus surgical technique in recent years has led to its application to anatomic areas outside the strict limits of the sinonasal cavities. Such minimally invasive approaches are safe, effective, and spare unnecessary discomfort to the patient. This article describes the authors' method for performing an endoscopic approach to the pterygopalatine space.  相似文献   
992.
Occupational diseases Nos. 2108 and 2110 correspond to intervertebral disc-related diseases of the lumbar spine from many years of carrying or lifting heavy loads, occupations in extreme postures of full flexion or oscillation of the whole body when seated, and which compel the cessation of all activities which are or could be the cause for the origin, exacerbation or recurrence of the disease. These occupational diseases came into force at the start of 1993, but there have been considerable problems in their implementation. The present Part I of the contribution is the result of the work of an interdisciplinary study group and contains medical criteria for the assessment of possibly strain-related clinical characteristics and the evaluation of other possible causes. Part II is to be published in Volume 4/2005 and will deal with questions related to forced cessation and to the assessment of the loss of earning ability. Agreement was reached in many areas related to the assessment of occupational claims. This should allow for evidence-based decision making in the future for the occupational diseases Nos. 2108 and 2110.  相似文献   
993.
Esophageus or gaster resection in patients with malignant disease is still a treatment of choice. It is obvious that each surgical procedure in these patients carries some possibility of complications. Esophageo-gastric or esophageo-jejuno anastomosis has a 4-27% frequency of fistula occurrence. All these result in 65% mortality in cases of poorer prognosis. The aim of this paper is not to present all types of complications but to objectively analyse the usefulness of the covered stent placement in the treatment of anastomotic fistulas. We present six patients who were treated for postoperative fistula of esophageo-gastric anastomosis (1 case) or esophageo-jejuno anastomosis (5 cases). All patients were treated with stapler suture for digestive tract reconstruction after malignancy removal during the primary surgical procedure. Signs and symptoms of suture leak between 5-8 days post-surgery were observed. Conservative therapy was not effective. Thus a new method of treatment was employed - covered stent placement. The procedure was performed under X-ray control. In all treated patients there was change for the better and quick reduction of secretion from the fistulas was observed. All patients were discharged from the department after several days and all had survived at 30 days follow-up. Covered esophageal stent placement seems to be a safe and promising method of treatment for patients with anastomotic fistula which significantly reduces mortality and improves quality of live. Our experiences confirms that of other investigators.  相似文献   
994.
Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on the established clinical applications of CT, and novel CT and MRI techniques, which may prove valuable in evaluating the structural and functional damage in COPD.  相似文献   
995.
996.
997.
Catecholaminergic polymorphic ventricular tachycardia is important to be diagnosed as an underlying disease in children with syncope and normal heart, because of its poor prognosis. CASE REPORT: A 3-year-old boy was referred for stress and emotion induced syncope. Primary ventricular arrhythmia, consisting of salvos of bidirectional ventricular tachycardia, was reproducibly induced by physical exertion. The syncopal events and severe arrhythmia disappeared with beta-blocking therapy. CONCLUSION: Despite its rare occurrence, catecholaminergic polymorphic ventricular tachycardia is an important cause of stress and emotion induced syncope and sudden death in children.  相似文献   
998.
999.
1000.
AIMS: Screening for diabetic retinopathy (DR) is highly inadequate in France because of insufficient infrastructure and increasing disease prevalence. We describe the results of the first systematic DR screening programme established in a university diabetes department. METHODS: In this cross-sectional study conducted over 1 year, consecutive adult patients underwent three-field retinal photography with the Topcon TRC NW6S digital fundus camera following pupillary dilatation with Tropicamide 1%. A questionnaire provided information on patients' systemic and ocular history. Glycated haemoglobin (HbA1c) was measured at the screening visit.Two ophthalmologists graded the retinal photographs in a masked fashion. RESULTS: Of 1157 patients attending the diabetes department, 1153 (99.7%)underwent photographic screening. Images were gradable in 96% patients.Diabetic retinopathy was detected in 522 (45%) patients and sight-threatening DR in 167 (14%). Of 704 (61%) patients previously believed to have no DR,254 (34%) screened positive. The presence of DR was associated with age,insulin use and non-Caucasian ethnicity in Type 2 patients, and with duration of diabetes and HbA1c in Type 1 and Type 2 patients. Associated ocular pathologies were diagnosed in 612 (53%) patients. CONCLUSIONS: Our photographic screening programme using pharmacological mydriasis provided a high screening coverage feasible in a hospital setting. We obtained information regarding prevalence and associated risk factors of DR inpatients attending a tertiary care centre. Screening was well accepted by patients and met with no protest from city ophthalmologists. It generated considerable interest among endocrinologists and feedback of results is expected to improve optimization of glycaemic control.  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