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   2432篇
  免费   260篇
  国内免费   21篇
耳鼻咽喉   45篇
儿科学   104篇
妇产科学   69篇
基础医学   376篇
口腔科学   28篇
临床医学   317篇
内科学   481篇
皮肤病学   70篇
神经病学   121篇
特种医学   224篇
外科学   289篇
综合类   58篇
一般理论   3篇
预防医学   245篇
眼科学   18篇
药学   185篇
  1篇
中国医学   1篇
肿瘤学   78篇
  2021年   24篇
  2020年   29篇
  2019年   44篇
  2018年   40篇
  2017年   36篇
  2016年   35篇
  2015年   31篇
  2014年   53篇
  2013年   86篇
  2012年   112篇
  2011年   98篇
  2010年   57篇
  2009年   47篇
  2008年   84篇
  2007年   107篇
  2006年   97篇
  2005年   87篇
  2004年   72篇
  2003年   72篇
  2002年   65篇
  2001年   58篇
  2000年   70篇
  1999年   76篇
  1998年   42篇
  1997年   35篇
  1996年   35篇
  1995年   30篇
  1994年   38篇
  1993年   35篇
  1992年   54篇
  1991年   43篇
  1990年   61篇
  1989年   65篇
  1988年   60篇
  1987年   68篇
  1986年   53篇
  1985年   61篇
  1984年   39篇
  1983年   44篇
  1982年   36篇
  1981年   35篇
  1980年   27篇
  1979年   48篇
  1978年   23篇
  1977年   22篇
  1976年   31篇
  1975年   25篇
  1974年   28篇
  1973年   31篇
  1970年   20篇
排序方式: 共有2713条查询结果,搜索用时 62 毫秒
11.
12.
13.
14.
Dolichospondylic dysplasia (DD) is a rare skeletal dysplasia primarily characterized by tall vertebral bodies and disproportionate short stature. Radiographic manifestations include tall vertebral bodies and gracile bones of the hands. Patients usually have eye and ear findings in addition to borderline mental retardation; however, tall vertebral bodies and slender tubular bones are also seen in the 3-M syndrome. Patients with the 3-M syndrome have a characteristic face with a triangular shape, frontal bossing, a flattened malar region, full eyebrows, a short nose with a bulbous tip, upturned nares, and full lips. We present two unrelated patients who share a distinct phenotype and have tall vertebral bodies, overtubulation of long bones, and short tubular bones of the hands and feet. We discuss the overlapping and distinguishing features between DD and the 3-M syndrome. Patient 1 was a 13-year-old female, and patient 2 was an unrelated adult female. These patients had normocephaly and short stature. They shared a common phenotype consisting of mild malar hypoplasia, a narrowed nasal body with a fleshy tip, full lips, and normal intelligence. In addition, they showed mild hand and foot abnormalities. These two patients lack many of the typical clinical features of both DD and the 3-M syndrome. They share a common phenotype and likely represent a distinct disorder. The spectrum of disorders with tall vertebral bodies as a key feature may include different entities that may be further defined with the characterization of the molecular defect(s).  相似文献   
15.
The Kabuki syndrome is a well-established pattern of human malformation with readily recognizable features, however the diagnosis is rarely made in the newborn period. The purpose of this study was to determine if there exists a neonatal phenotype for this disorder. We ascertained 16 infants evaluated in the first 28 days of life by a dysmorphologist who subsequently received the diagnosis of Kabuki syndrome. The average age of initial evaluation was 8 days and the average age of diagnosis was 2 years 6 months. Based on these findings, it is suggested that the distinctive clinical phenotype seen in older patients is also evident in the newborn period.  相似文献   
16.
Value of electron microscopy in diagnosis of renal disease.   总被引:2,自引:1,他引:2       下载免费PDF全文
AIMS--To assess the role and value of electron microscopy in the diagnosis of renal disease. METHODS--Retrospective evaluation of 88 renal biopsy specimens received for primary diagnosis by assessment of the contribution of electron microscopy to the final diagnosis in the knowledge of the light microscopy and immunofluorescence findings. RESULTS--Electron microscopy had an important diagnostic role in 75% of cases and was essential or necessary for diagnosis in 25%. In 25% of cases electron microscopy was considered unhelpful in diagnosis. CONCLUSION--Electron microscopy has an integral role in the diagnosis of renal disease, and tissue should be taken for electron microscopy in all cases if possible. In some selected cases once the light microscopy and immunofluorescence findings are known it may be possible to forego electron microscopic examination. Electron microscopy is particularly useful in the differential diagnosis of minimal change disease and the nephrotic syndrome.  相似文献   
17.
Rothmund-Thomson syndrome associated with trisomy 8 mosaicism.   总被引:2,自引:2,他引:2       下载免费PDF全文
This report describes a boy with Rothmund-Thomson syndrome associated with trisomy 8 mosaicism. The patient presented with typical features of Rothmund-Thomson syndrome but some of the features often seen in trisomy 8 mosaics were also observed in him. The possibility that the two disorders might share a common pathogenesis is postulated.  相似文献   
18.
The (+) and (?) enantiomers of 2-amino-5-phosphono-valeric acid have been separated and tested as antagonists of aminoacid excitation of neurones in rat cerebral cortex. The compounds were applied by microiontophoresis. The (?)-isomer was about 8–10 times more active than the racemate in blocking responses to N-methyl-d-aspartate, and was better able to distinguish between N-methyl-d-aspartate and glutamate.The results support the concept of a distinct population of receptors for N-methyl-d-aspartate.  相似文献   
19.
20.
Osteosarcomatosis   总被引:10,自引:0,他引:10  
A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.  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