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   1331篇
  免费   109篇
  国内免费   1篇
耳鼻咽喉   114篇
儿科学   45篇
妇产科学   8篇
基础医学   222篇
口腔科学   19篇
临床医学   87篇
内科学   295篇
皮肤病学   14篇
神经病学   112篇
特种医学   46篇
外科学   130篇
综合类   4篇
预防医学   153篇
眼科学   6篇
药学   99篇
肿瘤学   87篇
  2023年   6篇
  2022年   8篇
  2021年   19篇
  2020年   12篇
  2019年   15篇
  2018年   19篇
  2017年   24篇
  2016年   29篇
  2015年   25篇
  2014年   55篇
  2013年   55篇
  2012年   73篇
  2011年   82篇
  2010年   37篇
  2009年   47篇
  2008年   73篇
  2007年   64篇
  2006年   69篇
  2005年   82篇
  2004年   69篇
  2003年   71篇
  2002年   74篇
  2001年   58篇
  2000年   55篇
  1999年   51篇
  1998年   26篇
  1997年   20篇
  1996年   14篇
  1995年   17篇
  1994年   10篇
  1993年   11篇
  1992年   23篇
  1991年   15篇
  1990年   11篇
  1989年   18篇
  1988年   12篇
  1987年   12篇
  1986年   13篇
  1985年   13篇
  1984年   6篇
  1983年   4篇
  1982年   5篇
  1981年   3篇
  1980年   7篇
  1979年   3篇
  1973年   3篇
  1972年   2篇
  1971年   4篇
  1970年   3篇
  1968年   4篇
排序方式: 共有1441条查询结果,搜索用时 15 毫秒
101.

Background  

Early sexual maturation has been associated with overweight that may persist after the completion of biological growth and development. We have prospectively examined the influence of early sexual maturation on subsequent overweight in late adolescence and assessed if this association was modified by central adiposity in early adolescence.  相似文献   
102.
A 70-year-old woman was referred because of vision deterioration of her right eye since several months. With optimal spheric correction of +2.50 in her right eye she had a vision of 0.7. The intraocular pressure was 10 mmHg. There were no abnormalities in the anterior chamber of the eye. The right eye did show a palette of coloured needle-shaped opacities in the cortex and anterior nucleus of the lens, consistent with unilateral Christmas tree cataract.  相似文献   
103.
The effect of positive expiratory pressure breathing, alone and in combination with coughing, was investigated in eight patients with cystic fibrosis. Functional residual capacity and total lung capacity was measured with a body plethysmograph before, during, and immediately after breathing with expiratory pressure of 5 and 15 cm H2O, and after a coughing period. The positive expiratory pressure breathing was carried out five times for two minutes with a two minute interval between each period. Mucus transport was measured in a peripheral lung region and over the whole lung by a radioactive aerosol tracer technique. Clearance measurements were carried out continuously during positive expiratory pressure breathing and during a control period. Two minutes' breathing with an expiratory pressure of 5 and 15 cm H2O caused an increase in mean (SEM) functional residual capacity from 2.6 (0.1) to 3.6 (0.3) and 4.4 (0.5) 1 and an increase in total lung capacity from 5.1 (0.2) to 5.9 (0.3) and 6.9 (0.4) 1. Lung volumes were higher during breathing with an expiratory pressure of 15 cm H2O than with 5 cm H2O; both returned to baseline values immediately after positive expiratory pressure breathing. Spontaneous mucus clearance and mucus clearance by coughing were not influenced by positive expiratory pressure breathing at either expiratory pressure. Thus in patients with cystic fibrosis positive expiratory pressure breathing increases lung volumes in relation to the expiratory pressure imposed; these changes in lung volume did not, however, lead to an improvement of mucus transport.  相似文献   
104.
The study addressed the question whether the novel inhaled prodrug corticosteroid ciclesonide is equally effective when inhaled in the morning compared to the evening. For this purpose a double-blind, randomized, parallel group study was initiated in which 209 asthmatic patients (forced expiratory volume in one second = 50-90% predicted) inhaled either 200 microg ciclesonide in the morning or in the evening, for 8 weeks. Efficacy was assessed by means of spirometry as well as daily recordings of morning and evening peak expiratory flow (PEF), symptoms and use of rescue medication. The 24-h urinary cortisol excretion was measured to evaluate any effect on hypothalamic-pituitary-adrenol axis. Ciclesonide significantly improved asthma control. Morning and evening administration was shown to be equally effective for the different spirometry variables, evening PEF, symptoms, use of rescue medication and number of asthma exacerbations. Regarding morning PEF, the improvements after evening dosing were more prominent and equivalence of morning and evening administration could not be demonstrated. No relevant influence on cortisol excretion was found. Overall, the study indicates that ciclesonide can be given either in the morning or in the evening to meet the patients' preference and individual medical needs, although evening administration may lead to a more pronounced improvement in morning peak expiratory flow.  相似文献   
105.
106.
107.
108.
In a longitudinal investigation 103 kidney recipients were studied with respect to the development of cytomegalovirus (CMV) specific antibodies of the IgG and IgM class, in relation to the detection of CMV antigenaemia (immediate early antigen, IEA), in weekly obtained blood samples during the first 3 months after transplantation. In 15 out of 49 (31%) seronegative patients a primary infection occurred, which was characterized by a quick rise in IgM antibody followed by a slower production of IgG antibody, high maximum numbers of IEA+ cells, and a CMV syndrome in 11 patients. In 35 out of 54 (65%) seropositive patients a secondary infection occurred. After a post-operative fall in the IgG antibody, which was also found in patients without an active infection and which was accompanied by a similar drop in serum albumin and IgG, a second dip in IgG antibody was found 6 days before the first IEA+ leucocyte appeared in the blood. This was followed by a significant increase, indicative of an active immune response in consequence of the infection, 18 days later. In 31 of these 35 patients an IgM response was found. This could be ascribed to the presence of rheumatoid factor activity in 20 of them. Eight patients who showed a transient rise in IgG antibody between the two dips could be distinguished from the remaining ones by a lower maximum number of IEA+ cells and less severe disease symptoms. The described results suggest that (i) an adequate humoral immune system may prevent symptomatic CMV disease in secondary infections; and (ii) CMV-specific antibodies may be removed from the circulation by antigens present in infected tissues before CMV antigenaemia becomes detectable.  相似文献   
109.

Background

The newly registered adjuvanted herpes zoster subunit vaccine (HZ/su) has a higher efficacy than the available live-attenuated vaccine (ZVL). National decision-makers soon need to decide whether to introduce HZ/su or to prefer HZ/su above ZVL.

Methods

Using a Markov model with a decision tree, we conducted a cost-effectiveness analysis of vaccination with HZ/su (two doses within 2?months) or zoster vaccine live (ZVL) (single dose, or single dose with a booster after 10?years) for cohorts of 50-, 60-, 70- or 80-year-olds in the Netherlands. The model was parameterized using vaccine efficacy data from randomized clinical trials and up-to-date incidence, costs and health-related quality of life data from national datasets. We used a time horizon of 15?years, and the analysis was conducted from the societal perspective.

Results

At a coverage of 50%, vaccination with two doses of HZ/su was estimated to prevent 4335 to 10,896 HZ cases, depending on the cohort age. In comparison, this reduction was estimated at 400–4877 for ZVL and 427–6466 for ZVL with a booster. The maximum vaccine cost per series of HZ/su to remain cost-effective to a willingness-to-pay threshold of €20,000 per quality-adjusted life year (QALY) gained ranged from €109.09 for 70-year-olds to €63.68 for 50-year-olds. The cost-effectiveness of ZVL changed considerably by age, with corresponding maximum vaccine cost per dose ranging from €51.37 for 60-year-olds to €0.73 for 80-year-olds. Adding a ZVL booster after 10?years would require a substantial reduction of the maximum cost per dose to remain cost-effective as compared to ZVL single dose. Sensitivity analyses on the vaccine cost demonstrated that there were scenarios in which vaccination with either HZ/su (two doses), ZVL single dose or ZVL + booster could be the most cost-effective strategy.

Conclusions

A strategy with two doses of HZ/su was superior in reducing the burden of HZ as compared to a single dose or single dose + booster of ZVL. Both vaccines could potentially be cost-effective to a conventional Dutch willingness-to-pay threshold for preventive interventions. However, whether HZ/su or ZVL would be the most cost-effective alternative depends largely on the vaccine cost.
  相似文献   
110.
Introduction: Loneliness is the subjective negative evaluation of social participation and isolation. Emotional loneliness reflects the absence of close relationships, and social loneliness the absence of a social network. Although loneliness is a growing problem in modern society, studies about loneliness in patients with Korsakoff’s syndrome (KS) in need of chronic care are currently missing.

Methods: Sixty-three KS patients in long-term care and their primary caregivers reported loneliness of the patients on the De Jong Gierveld Loneliness Scale.

Results: A majority of KS patients reliably reported to feel lonely on both a social and emotional level of loneliness. The caregiving professionals rated loneliness of the patients even higher. Patients that had stayed in the clinic for a longer time tended to report less social loneliness, while caregivers reported less emotional loneliness in those patients. The KS-specific neuropsychiatric symptom of confabulations and a lack of social visits had a negative impact on social loneliness as perceived by the caregivers.

Conclusion: Loneliness is a large problem in patients with KS that live in a long term care facility. Social loneliness can be positively influenced by creating possibilities to interact with other people, although the severity of the neuropsychiatric aspects of KS could compromise the presence of those interactions.  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