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   3363篇
  免费   338篇
  国内免费   4篇
耳鼻咽喉   20篇
儿科学   127篇
妇产科学   80篇
基础医学   413篇
口腔科学   104篇
临床医学   317篇
内科学   587篇
皮肤病学   24篇
神经病学   399篇
特种医学   113篇
外科学   468篇
综合类   70篇
一般理论   5篇
预防医学   501篇
眼科学   95篇
药学   167篇
中国医学   2篇
肿瘤学   213篇
  2021年   35篇
  2019年   48篇
  2018年   43篇
  2017年   57篇
  2016年   41篇
  2015年   51篇
  2014年   73篇
  2013年   103篇
  2012年   174篇
  2011年   175篇
  2010年   92篇
  2009年   113篇
  2008年   161篇
  2007年   211篇
  2006年   190篇
  2005年   191篇
  2004年   191篇
  2003年   162篇
  2002年   139篇
  2001年   88篇
  2000年   70篇
  1999年   81篇
  1998年   46篇
  1997年   45篇
  1996年   35篇
  1995年   38篇
  1994年   25篇
  1993年   23篇
  1992年   43篇
  1991年   43篇
  1990年   49篇
  1989年   48篇
  1988年   44篇
  1987年   48篇
  1986年   44篇
  1985年   40篇
  1984年   54篇
  1983年   35篇
  1982年   40篇
  1981年   33篇
  1980年   29篇
  1979年   26篇
  1978年   29篇
  1977年   26篇
  1976年   28篇
  1974年   40篇
  1973年   32篇
  1972年   34篇
  1971年   32篇
  1968年   22篇
排序方式: 共有3705条查询结果,搜索用时 0 毫秒
1.
2.
3.
Alemtuzumab is a powerful lymphocyte depleting antibody currently being evaluated in solid organ transplantation. This paper describes 5-year results of a single center study of alemtuzumab as induction in renal transplantation. Thirty-three renal transplant recipients received 20 mg alemtuzumab on day 0 and 1, followed by half-dose cyclosporin monotherapy (trough concentration 75-125 ng/mL) from day 3. They were compared in a retrospective contemporaneous-controlled manner with 66 kidney transplant recipients transplanted in the same period and center who received conventional immunosuppression with cyclosporin, azathioprine and prednisolone. In the alemtuzumab group 12% of recipients died compared to 17% in the control group (p = 0.48); likewise graft loss was similar in both groups (21% vs. 26%, respectively, p = 0.58). Incidence of acute rejection was also comparable at 5 years (31.5% vs. 33.6%), although the pattern of rejection was different with 14% patients in the alemtuzumab group experiencing rejection over 1 year post-transplant compared to none in the control group. There was no significant difference between groups in terms of infection or serious adverse events. While acknowledging the limitations of a relatively small single-center study, results suggest that alemtuzumab induction allowed satisfactory long-term patient and graft survival equivalent to that seen with standard triple immunosuppression, while avoiding steroid therapy.  相似文献   
4.
5.
6.
Exercise is associated with a reduced risk of coronary heart disease, has beneficial effects on cardiovascular risk factors, and has other health benefits. No more than 10 per cent to 20 per cent of adults in Australia and other developed countries participate in regular vigorous physical activity, while over 65 per cent of Australian adults are almost totally sedentary. Survey data from the U.S.A. suggest that levels of participation in jogging and walking have increased in the past 10 years but that the proportion of people who take no deliberate exercise has also increased. Large-scale community interventions to promote exercising have not been subject to rigorous evaluation and it is difficult to reach any firm conclusions about the effects of exercise promotion. However, it is possible to identify some of the factors which may influence exercise participation, and there is information from trials of large-scale, multifactorial interventions to reduce cardiovascular risk which provides some helpful guidelines about how it may be useful to proceed. Approaches to increasing levels of exercise participation should emphasise community-based efforts which provide appropriate settings and social support for exercising, making exercise a more appealing and accessible option for large numbers of people; the use of mass media for community education about exercising should be co-ordinated carefully with specific community activities. Personalized fitness instruction, groups and classes should place more emphasis on exercise as a pattern of behaviour to be integrated into a person's way of life and maintained over time; and there is the potential for more widespread and systematic use of self-instructional exercise materials to assist people who wish to exercise independently. Because there exist only limited local research findings and work in other countries does not yet provide conclusive information, research and development priorities for these areas are suggested.  相似文献   
7.
Analytic, within-subject, and between-subject biologic variations were estimated for leukocytes, erythrocytes, hemoglobin, hematocrit, mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin content (MCHC), platelets, and a three-component differential count (lymphocytes, monocytes, and granulocytes in terms of both concentration and percentage of leukocytes) in cohorts of 12 male and 12 female healthy elderly subjects. The assays were performed with an Ortho ELT-800 automated analyzer. The estimates of within-subject biologic variation were similar to published data on young subjects, indicating that this aspect of homeostasis is not compromised in the elderly. The data were used to derive objective analytic goals; goals were surpassed except for assays of erythrocytes, hematocrit, and the derived MCV, MCH, and MCHC. The changes required for serial results to be significantly different were determined and found to be generally valid because most quantities have no heterogeneity of within-subject variation. All quantities had significant individuality; in consequence, conventional population-based reference values are of limited utility, and screening using reference limits will not detect latent or early disease in many subjects.  相似文献   
8.
9.
A rare case of thymic carcinoma with multiple brain metastasis is reported. In our extensive review of the literature only six of 30 reports of intracranial thymoma metastasis describe multiple metastases. A 38-year-old man presented with signs of raised intracranial pressure that had began 15 days previously. Cranial MRI revealed over 70 cystic lesions in the supra and infratentorial regions. Stereotactic biopsy was planned. On the second day of his admission he deteriorated and died the following day. The autopsy revealed a mass in the mediastinum. In the brain parenchyma were multiple cystic lesions between 0.5 and 3 cm in diameter. Histopathologically they were diagnosed as metastases from the thymic carcinoma. The mean survival with a single brain metastasis is approximately 256 days, whereas with multiple brain metastases it is only 64 days, thus treatment of this tumor demands prompt surgery whenever possible and optimal adjuvant therapy.  相似文献   
10.
Gas-producing diabetic foot infections are limb-threatening emergencies commonly encountered by foot and ankle surgeons. Appropriate treatment includes aggressive surgical debridement, parenteral antibiotics, and postoperative wound care. The authors present a unique case of a patient who refused treatment for a deep-space gas-producing infection, resulting in autoamputation of the foot. The authors also discuss the confusion surrounding the definition of gas gangrene.  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