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   1367篇
  免费   68篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   75篇
妇产科学   14篇
基础医学   119篇
口腔科学   26篇
临床医学   188篇
内科学   254篇
皮肤病学   23篇
神经病学   83篇
特种医学   260篇
外科学   134篇
综合类   18篇
预防医学   45篇
眼科学   4篇
药学   123篇
中国医学   1篇
肿瘤学   68篇
  2023年   3篇
  2022年   3篇
  2021年   6篇
  2020年   3篇
  2019年   5篇
  2018年   18篇
  2017年   14篇
  2016年   15篇
  2015年   19篇
  2014年   27篇
  2013年   33篇
  2012年   47篇
  2011年   30篇
  2010年   60篇
  2009年   52篇
  2008年   43篇
  2007年   43篇
  2006年   37篇
  2005年   44篇
  2004年   34篇
  2003年   29篇
  2002年   25篇
  2001年   29篇
  2000年   26篇
  1999年   25篇
  1998年   53篇
  1997年   67篇
  1996年   56篇
  1995年   42篇
  1994年   55篇
  1993年   56篇
  1992年   19篇
  1991年   27篇
  1990年   16篇
  1989年   44篇
  1988年   51篇
  1987年   33篇
  1986年   35篇
  1985年   32篇
  1984年   15篇
  1983年   27篇
  1982年   18篇
  1981年   22篇
  1980年   25篇
  1979年   10篇
  1978年   11篇
  1977年   16篇
  1976年   10篇
  1975年   18篇
  1882年   2篇
排序方式: 共有1438条查询结果,搜索用时 46 毫秒
1.
2.
Conventional risk factors have very low predictive power in identifying haemodialysis patients at high risk of vascular accidents. A role for apolipoprotein E isotypes was looked for in a small, but rigorously defined, cohort of longterm haemodialysis patients. In individuals with high vascular risk, as identified by higher common carotid intima/media thickness, we found an excess of apolipoprotein E4 alleles. This preliminary result requires confirmation in large patient cohorts.   相似文献   
3.
4.
5.
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   
6.
Solitary bronchioloalveolar carcinoma: CT criteria   总被引:14,自引:0,他引:14  
The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis.  相似文献   
7.
Blood indicators of eight vitamins (B1, B2, B6, C, E, A, B12, folate) and six minerals (Cu, Mg, Zn, Ca, P, Al) were measured in 86 athletes before and after a 7- to 8-month period of training. During this period half consumed a multivitamin/mineral supplement and a matched group took a placebo. Following the supplementation period, blood biochemical indicators of B1, B6, B12, and folate status all increased but there were no significant effects of supplementation on B2, C, E, and A, or on the blood levels of any of the minerals. The supplementation had no effect on red or white cell counts or on hemoglobin levels. Irrespective of the supplementation, some blood measures varied according to sex, females evidencing significantly higher values than males for vitamins C, E, copper, magnesium, and aluminium, with B2 being higher in males. It is concluded that 7 to 8 months of multivitamin/mineral supplementation increased the blood nutritional status of some vitamins but did not affect any blood mineral levels, and that some blood nutritional indicators may vary according to sex.  相似文献   
8.
9.
OBJECTIVE: The aim was to establish the potential efficacy, tolerabilityand side-effect profile of electromagnetic therapy as an adjunctto conventional dressings in the treatment of venous leg ulcers. METHOD: A prospective, randomized, double blind controlled clinicaltrial was carried out in a dedicated leg ulcer clinic basedin one urban general practice. Nineteen patients with leg ulcersof confirmed venous aetiology were assessed. The main outcomemeasures were rate and scale of venous leg ulcer healing, changesin patient-reported pain levels, quality of life, degree ofmobility, side effect profile and acceptability to patientsand staff. RESULTS: Sixty-eight per cent of patients attending this dedicated clinicachieved improvements in the size of their ulcer (4, 21%, healedfully) and in reduced pain levels (P < 0.05) during the trial,despite the chronicity of ulcer histories. Patients treatedwith electromagnetic therapy at 800 Hz were found at day 50to have significantly greater healing (P < 0.05) and paincontrol (P < 0.05) than placebo therapy or treatment with600 Hz. All patients reported improved mobility at the end ofthe study. The electromagnetic therapy was well tolerated bypatients, with no differences between groups in reporting adverseevents, and proved acceptable to staff. CONCLUSION: Despite the small numbers in this pilot study, electromagnetictherapy provided significant gains in the healing of venousleg ulcers and reduction in pain. Keywords. Electromagnetic therapy, RCT, leg ulcers, primary care.  相似文献   
10.
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