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   593篇
  免费   15篇
  国内免费   16篇
耳鼻咽喉   3篇
儿科学   37篇
妇产科学   3篇
基础医学   28篇
口腔科学   6篇
临床医学   54篇
内科学   105篇
皮肤病学   4篇
神经病学   41篇
特种医学   162篇
外科学   97篇
综合类   45篇
预防医学   8篇
眼科学   1篇
药学   11篇
肿瘤学   19篇
  2021年   2篇
  2019年   2篇
  2018年   5篇
  2017年   2篇
  2015年   3篇
  2014年   5篇
  2013年   10篇
  2012年   5篇
  2011年   7篇
  2010年   8篇
  2009年   13篇
  2008年   5篇
  2007年   10篇
  2006年   9篇
  2005年   14篇
  2004年   11篇
  2003年   11篇
  2002年   13篇
  2001年   15篇
  2000年   14篇
  1999年   12篇
  1998年   24篇
  1997年   41篇
  1996年   49篇
  1995年   25篇
  1994年   27篇
  1993年   26篇
  1992年   14篇
  1991年   14篇
  1990年   7篇
  1989年   19篇
  1988年   23篇
  1987年   18篇
  1986年   32篇
  1985年   10篇
  1984年   9篇
  1983年   7篇
  1982年   12篇
  1981年   6篇
  1980年   10篇
  1979年   8篇
  1978年   15篇
  1977年   8篇
  1976年   12篇
  1975年   9篇
  1974年   4篇
  1973年   4篇
  1972年   4篇
  1971年   4篇
  1969年   3篇
排序方式: 共有624条查询结果,搜索用时 15 毫秒
31.
32.
33.
This study evaluated the accuracy of the interpretation of the chest film in delineating localised abnormalities of ventilation and perfusion, as well as the overall severity of airways obstruction, exercise tolerance, and clinical condition in children with cystic fibrosis. Radiographic findings in various regions of the chest film were compared with the functional values obtained with regional lung function tests which evaluated the arrival and disappearance of boluses of radioactive nitrogen given by inhalation and infusion. While the more severely affected areas on the chest radiograph were found to correlate with similar regions on the lung function tests, as did overall scores, errors occurred in some cases if the x-ray film alone was used as a judge of regional physiological derangement. In addition the degree of airways obstruction, the exercise tolerance on a cycle ergometer, and clinical grading, each correlated significantly with the radiographic score. We conclude that the chest radiograph is a good indicator of the overall severity of the lung disease and that it correlates well with exercise tolerance and clinical condition in cystic fibrosis.  相似文献   
34.
Computed tomographic (CT) scans used in the diagnosis and management of subdural hematomas were analyzed with respect to their contribution to angiography and surgery. There has been a progressive increase in the use of CT in evaluating post-traumatic and postoperative subdural hematomas at the Mayo Clinic. At present, 40% of all patients undergo operation on the basis of the CT findings alone. False-positive diagnoses revealed at surgery have decreased to less than 4%. Erroneous negative interpretations have involved 10% of all patients whose diagnosis was subdural hematoma. Criteria for the interpretation of scans have been established.  相似文献   
35.
急性有机磷农药中毒120例的救治   总被引:1,自引:0,他引:1  
0 引言 近年来 ,我科在救治急性有机磷农药 (organophos-phorus,OP)中毒方面 ,积累了一些经验 ,现报告如下 .1 对象和方法1 .1 对象 本组 1 2 0例符合《急诊急救学》中的诊断标准 [1 ](男 2 9例 ,女 91例 ) ,年龄 1 .5~ 70岁 ,平均 2 8.6岁 .经口中毒 99例 ,经皮肤中毒 2 1例 .轻度中毒 1 5例 ,中度中毒 42例 ,重度 (含极重度 )中毒 6 3例 . 1 996年 39例 ,1 997年 43例 ,1 998年 38例 . DDV 79例 ,乐果 2 0例 ,混合性中毒 1 0例 ,水胺磷 3例 ,氧化乐果、 391 1、 1 0 5 9、对硫磷各 2例 ,敌百虫 1例 ,药名不详 1 0例 .服毒量 >2 5 …  相似文献   
36.
37.
The relative risk of shunting versus not shunting during carotid endarterectomy was analyzed retrospectively in 1935 cases undergoing carotid endarterectomy for carotid ulcerative stenosis. The need for shunting was based on a correlation between electroencephalographic changes and a fall in cerebral blood flow below the critical level required for adequate perfusion during the period of carotid occlusion. Patients were divided into four risk categories for surgery, based on medical and neurological risks and angiographic findings. Shunts were required in 30% of the low risk group and 56% of the high risk group. Based on the severity of reductions of cerebral blood flow during the period of carotid occlusion it is concluded that 12% of all patients would have sustained a major deficit, 15% a minor or transient deficit, and 20% a transient deficit without shunting. The risk of shunting 792 cases in this series was 0.5%. Overall minor morbidity, major morbidity, and mortality each approximated 1% in this series.  相似文献   
38.
A review was done of 120 cases of malignant peripheral nerve sheath tumor (MPNST) seen during a 71-year period. Of the 120 patients, 52 were males and 68 were females with a mean age at diagnosis of 35.3 years; 12 patients were younger than 20 years. The series included 62 (52%) patients with neurofibromatosis, 13 (11%) with postradiation sarcomas, and 19 (16%) with metaplastic foci. The incidence of MPNST arising in neurofibromatosis was 4.6% in the current series and 0.001% in the general clinic population. Tumors greater than 5 cm and the presence of neurofibromatosis adversely affected the prognosis (P less than 0.05). When both features were present, survival was greatly decreased. Patients with tumor in the extremities did better than those with head or neck lesions. Metaplastic foci or previous radiation at the tumor site did not alter the prognosis. Each tumor was graded 1 to 4 on the basis of cellularity, pleomorphism, mitotic index, and necrosis. No significant correlation was noted between survival and either grade or mitotic rate. Survival was improved when total rather than subtotal resection was done. This was most marked in patients with a small lesion, which may reflect the difficulty in adequately excising large tumors. Adjuvant radiation or chemotherapy did not appear to affect survival. The MPNST is an aggressive uncommon neoplasm, and large tumor size, the presence of neurofibromatosis, and total resection are the most important prognostic indicators.  相似文献   
39.
The authors present the radiographic features of a previously incompletely delineated bone dysplasia, which they call spondylometaphyseal dysplasia, corner fracture type. This is a dominant heritable condition associated with short stature and developmental coxa vara. The progressive hip deformity usually causes significant disability requiring surgical correction. Developmental coxa vara, simulated corner fractures of long tubular bones, and vertebral body abnormalities result in a diagnostic constellation. Knowledge of these distinctive radiologic features allows accurate diagnosis, which in turn should lead to appropriate genetic counseling and possibly to earlier, more efficacious surgical treatment of the coxa vara.  相似文献   
40.
Spontaneous dissection of the cervical internal carotid artery   总被引:12,自引:0,他引:12  
We studied 36 patients (21 women and 15 men) with spontaneous dissection of the internal carotid arteries. The ages of these patients ranged from 21 to 63 years. Focal unilateral headache was the most common symptom. Other common clinical manifestations (in decreasing order of frequency) included focal cerebral ischemic symptoms, oculosympathetic paresis, bruits, light-headedness, and neck pain. Less common symptoms were syncope, amaurosis fugax, scalp tenderness, swelling in the neck, and dysgeusia. Common angiographic manifestations (in decreasing order of frequency) were elongated, irregular, and frequently tapered narrowing of the lumen; abrupt luminal reconstitution (often at the carotid canal); aneurysms; intimal flaps; slow internal carotid artery--middle cerebral artery flow; tapered occlusion; and distal branch occlusions. The incidence of hypertension in these patients was considerably higher than that in the general population. Angiographic evidence of fibromuscular dysplasia was found in 14% of the patients, but atherosclerotic changes were uncommon. Follow-up ranged from 14 to 140 months (mean, 58.5 months). Twenty-three patients with 29 dissected internal carotid arteries were also restudied angiographically. The stenosis of the internal carotid artery either completely resolved or substantially improved in more than 85% of the dissected vessels. About two-thirds of the dissecting aneurysms either resolved or decreased in size. Clinically more than 85% of the patients had an excellent or complete recovery. Recurrence of the dissection or rupture of a dissecting aneurysm was not noted. Despite their disconcerting appearance on angiography, spontaneous dissections of the internal carotid arteries are often associated with a good prognosis.  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