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   6235篇
  免费   741篇
  国内免费   3篇
耳鼻咽喉   89篇
儿科学   191篇
妇产科学   171篇
基础医学   763篇
口腔科学   169篇
临床医学   589篇
内科学   1367篇
皮肤病学   186篇
神经病学   373篇
特种医学   235篇
外科学   1028篇
综合类   222篇
一般理论   4篇
预防医学   587篇
眼科学   153篇
药学   327篇
中国医学   3篇
肿瘤学   522篇
  2021年   76篇
  2019年   85篇
  2018年   64篇
  2017年   60篇
  2016年   70篇
  2015年   93篇
  2014年   134篇
  2013年   200篇
  2012年   275篇
  2011年   247篇
  2010年   162篇
  2009年   150篇
  2008年   247篇
  2007年   257篇
  2006年   246篇
  2005年   283篇
  2004年   261篇
  2003年   264篇
  2002年   210篇
  2001年   169篇
  2000年   181篇
  1999年   170篇
  1998年   96篇
  1997年   86篇
  1996年   85篇
  1995年   77篇
  1994年   63篇
  1993年   64篇
  1992年   150篇
  1991年   122篇
  1990年   115篇
  1989年   107篇
  1988年   130篇
  1987年   93篇
  1986年   92篇
  1985年   83篇
  1984年   85篇
  1983年   108篇
  1982年   86篇
  1981年   66篇
  1980年   75篇
  1979年   85篇
  1978年   73篇
  1977年   67篇
  1976年   88篇
  1975年   71篇
  1974年   64篇
  1973年   66篇
  1971年   70篇
  1970年   57篇
排序方式: 共有6979条查询结果,搜索用时 15 毫秒
11.
12.
Risk Factors for a First Febrile Seizure: A Matched Case-Control Study   总被引:10,自引:6,他引:4  
Summary We conducted a matched casecontrol study to identify risk factors for first febrile seizures, with special emphasis on characteristics of the acute illness episode. Cases were identified through hospital emergency departments; controls were identified through outpatient clinics and emergency departments. Sixtynine children with first febrile seizures and no history of previous unprovoked seizures were matched for age (±6 months), site of routine pediatric care, and date of visit (±weeks) with 1 or 2 febrile controls who had no history of previous febrile or unprovoked seizures. Medical records for the index visit were reviewed, and parents were interviewed by telephone. Illness characteristics examined included height of temperature, type of underlying illness, contact with a physician during the illness but before the index visit, and use of acetaminophen or decongestants. Family history of febrile and of unprovoked seizures, sociodemographic characteristics, daycare use, and selected preand perinatal variables were also studied. On multivariable analysis, significant independent risk factors were height of temperature, history of febrile seizures in a firstor in a higher degree relative. Gastroenteritis as the underlying illness had a significant inverse (i.e., protective) association with febrile seizures. Maternal smoking during pregnancy was a marginally significant predictor of febrile seizures.  相似文献   
13.
14.
This report presents for the first time the results of carrying out epikeratophakia with tissue lathed at room temperature. Using an experimental model of epikeratophakia in the rabbit, we evaluated tissue handling techniques for the preparation of donor lenticules. Details of the technique are described and the in-vivo and histopathological findings reported.  相似文献   
15.
The striated urethral sphincter is the predominant muscular structure divided posteriorly during the apical dissection in radical prostatectomy. The authors have long realized the value of this maneuver in obtaining excellent apical surgical margins and in identifying the correct plane on the anterior surface of the rectum. Recently, they also have recognized the importance of incorporating this musculature into the vesicourethral anastomosis to fix the bladder neck and thus re-establish anatomic continuity. Identification of the striated urethral sphincter ranks in importance with elucidation of the anatomy of the dorsal vein complex and the anatomic identification of the neurovascular bundle in improving the patient's quality of life postoperatively.  相似文献   
16.
17.
To determine the prognosis of patients with lymph node metastases from an unknown primary melanoma, we retrospectively reviewed the clinicopathologic features of 188 such patients treated from 1971 through 1986 and compared their records with those of patients with clinical stage II melanoma with known primary lesions. Patients with lymph node metastases from an unknown primary melanoma represented 4.6% of all patients with melanoma treated during that period. The five- and ten-year survival rates were 42% and 40%, respectively (median, 37 months). When stratified by number of tumor-containing lymph nodes, there was no significant difference in survival between patients with an unknown primary melanoma and lymph node metastases and those with clinical stage II melanoma and known primary sites. The prognosis of the former patients is no worse than that of patients with lymph node metastases from a known primary site and should be treated in a comparable manner.  相似文献   
18.
19.
We used immunohistochemistry to evaluate four cytologically malignant cutaneous neoplasms on the face or neck of elderly individuals. All four lesions were composed of a dermal proliferation of spindle and pleomorphic giant cells. Differential diagnosis included spindle cell carcinoma, atypical fibroxanthoma, malignant melanoma, leiomyosarcoma, and angiosarcoma. All four neoplasms were strongly immunoreactive for vimentin and negative for cytokeratin, S100 protein, desmin, and factor-VIII-related antigen. Focal immunoreactivity for lysozyme and/or a1-antichymotrypsin was seen in the giant cells of each lesion. These results supported the diagnosis of atypical fibroxanthoma in each instance. Immunohistochemical staining can provide useful information for distinguishing among malignant cutaneous spindle cell tumors.  相似文献   
20.
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