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   726篇
  免费   82篇
  国内免费   19篇
儿科学   24篇
妇产科学   23篇
基础医学   91篇
口腔科学   12篇
临床医学   40篇
内科学   223篇
皮肤病学   18篇
神经病学   14篇
特种医学   85篇
外科学   127篇
综合类   12篇
一般理论   1篇
预防医学   48篇
眼科学   17篇
药学   23篇
中国医学   2篇
肿瘤学   67篇
  2021年   5篇
  2020年   7篇
  2019年   6篇
  2018年   12篇
  2017年   8篇
  2016年   8篇
  2015年   8篇
  2014年   13篇
  2013年   24篇
  2012年   17篇
  2011年   20篇
  2010年   32篇
  2009年   26篇
  2008年   34篇
  2007年   41篇
  2006年   35篇
  2005年   23篇
  2004年   16篇
  2003年   20篇
  2002年   17篇
  2001年   26篇
  2000年   18篇
  1999年   19篇
  1998年   22篇
  1997年   19篇
  1996年   18篇
  1995年   16篇
  1994年   17篇
  1993年   22篇
  1992年   12篇
  1991年   12篇
  1990年   24篇
  1989年   27篇
  1988年   27篇
  1987年   28篇
  1986年   22篇
  1985年   16篇
  1984年   13篇
  1983年   13篇
  1982年   8篇
  1981年   6篇
  1980年   8篇
  1979年   9篇
  1978年   6篇
  1977年   13篇
  1976年   7篇
  1975年   3篇
  1974年   3篇
  1973年   3篇
  1931年   2篇
排序方式: 共有827条查询结果,搜索用时 15 毫秒
1.
2.

Background  

Cerebrospinal fluid (CSF) pleocytosis may be seen in asymptomatic HIV-infected individuals. This finding complicates interpretation of CSF abnormalities when such individuals are evaluated for other central nervous system infections. The goal of this study was to determine the relationship between CSF pleocytosis, central nervous system (CNS) antiretroviral penetration, adherence to antiretroviral medication regimens, neurological symptoms and performance on neuropsychological tests.  相似文献   
3.
BACKGROUND: To evaluate the results of the tension-free vaginal tape procedure (TVT) from a patient's perspective. METHODS: Between May 1999 and January 2002, 90 patients underwent a TVT for genuine stress incontinence (GSI) and mixed incontinence. Prior to the procedure, GSI was confirmed by clinical examination and urodynamic studies. Results were then audited from patient notes and the same patients were sent questionnaires to examine results from a patient perspective. RESULTS: Overall response rate to the questionnaire was 70 (77%). The mean age of the patients was 50.4 years (range 31-83 years). Sixty-one patients had spinal anesthesia, seven had general anesthesia and two had local anesthesia. Mean hospital stay was 3.36 days (range 2-14 days) and mean period from the operation to the time of the survey and audit was 16.34 months (range 3-28; SD 6.92). Thirty-nine (56%) of the 70 patients who answered said that the operation had cured their incontinence, 16 (23%) had an improvement in their symptoms, 7 (10%) had worsening of their symptoms and 8 (11%) felt that the operation did not make any difference. The overall success rate according to the patients' perspective was 79%, whereas our audit showed an overall success rate of 86% (77% and 82%, respectively, when we compared only the 66 patients who had both notes and replies available for analysis). CONCLUSION: Although a patient's perception regarding the success of TVT tends to differ from that of a clinician, it was not found to be statistically significant (P = 0.22, McNemar test). The TVT is a very successful operation, but realistic cure rates should be offered to patients.  相似文献   
4.
Hodgkin disease: CT of the thymus   总被引:2,自引:0,他引:2  
Heron  CW; Husband  JE; Williams  MP 《Radiology》1988,167(3):647-651
The computed tomography (CT) scans in two groups of patients with Hodgkin disease were reviewed to determine the frequency of thymic enlargement. In 50 CT scans from 50 patients with evidence of thoracic disease on CT scans who were examined for primary staging, the thymus was enlarged in 15 of 50 (30%). Fifty CT scans were obtained from 44 patients at the time of 50 separate episodes of known or suspected relapse. Relapse occurred in the mediastinum in 12 episodes, lung parenchyma in five, and both sites in one. Thymic enlargement thought to be due to involvement by disease was present in seven of 18 (38%). Mediastinal disease was associated with thymic enlargement in all but one patient in whom a thymic cyst developed after radiation therapy. Differentiation of thymic enlargement from enlarged superior mediastinal lymph nodes was easily made in all but two patients. Thymic enlargement in the absence of lymph node enlargement may indicate a different disease, since isolated Hodgkin disease of the thymus is uncommon. Primary thymic tumor should be considered initially, whereas after treatment, rebound hyperplasia of the thymus may be the cause of enlargement.  相似文献   
5.
Solid and papillary epithelial neoplasms of the pancreas: CT findings   总被引:1,自引:0,他引:1  
Choi  BI; Kim  KW; Han  MC; Kim  YI; Kim  CW 《Radiology》1988,166(2):413-416
Five female patients and one male patient with solid and papillary epithelial neoplasms of the pancreas were examined with computed tomography (CT). The mean age of the patients was 27 years (range, 13-46 years). All cases showed well-encapsulated, round or lobulated masses consisting of both cystic and solid areas. Cystic portions showed CT numbers that suggested hemorrhagic necrosis. There were no internal septations within the masses. In three tumors located in the head of the pancreas, dilatation of the biliary tree was absent or minimal, although the masses were large. Two tumors contained calcifications. One tumor demonstrated metastatic deposits in liver and lymph nodes. Metastatic masses appeared similar to the primary pancreatic mass. Solid and papillary neoplasm of the pancreas should be the primary diagnostic consideration when characteristic CT findings are detected in a young female patient.  相似文献   
6.
A patient who received one of the first homograft valves in Canada in 1965 is presented. Recent assessment including cardiac catheterization has shown that the valve is functioning well after 21 years. The patient is presented for historic interest, since this may be one of the longest functioning homograft valves.  相似文献   
7.
8.
9.
The development of the tracheal submucosal glands has been determined quantitatively in 22 infants with cystic fibrosis and in 25 control infants, all under 4 months of age. In cross-sections of normal trachea significant relationships were found between postconceptional age (PCA) and gland area (P less than 0.001), submucosal area (P less than 0.02), tracheal airway diameter (P less than 0.05), and acinar diameter (P less than 0.001). In infants with cystic fibrosis the pattern of development was similar to that of the control infants. No statistically significant differences were found between three subgroups of infants with cystic fibrosis, which included those with meconium ileus with no lung infection, those with meconium ileus with lung infection, and those with lung infection and no history of meconium ileus. The normal pattern of development of tracheal submucosal glands in infants with cystic fibrosis was in contrast to the deficiency of normal maturation seen in the exocrine pancreas of these infants. The lumen fraction, an index of dilatation of acinar lumina, showed no significant relationship with PCA in either the control group or the group with cystic fibrosis. However, statistically significant dilatation of acini was observed in the tracheal submucosal glands of infants with cystic fibrosis (0.14, P less than 0.005).  相似文献   
10.

Background  

Missing data is a challenging problem in many prognostic studies. Multiple imputation (MI) accounts for imputation uncertainty that allows for adequate statistical testing. We developed and tested a methodology combining MI with bootstrapping techniques for studying prognostic variable selection.  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