全文获取类型
收费全文 | 2902篇 |
免费 | 186篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 77篇 |
妇产科学 | 93篇 |
基础医学 | 284篇 |
口腔科学 | 86篇 |
临床医学 | 381篇 |
内科学 | 516篇 |
皮肤病学 | 27篇 |
神经病学 | 168篇 |
特种医学 | 185篇 |
外科学 | 356篇 |
综合类 | 66篇 |
一般理论 | 4篇 |
预防医学 | 369篇 |
眼科学 | 126篇 |
药学 | 188篇 |
1篇 | |
肿瘤学 | 182篇 |
出版年
2022年 | 24篇 |
2021年 | 56篇 |
2020年 | 18篇 |
2019年 | 48篇 |
2018年 | 56篇 |
2017年 | 38篇 |
2016年 | 40篇 |
2015年 | 54篇 |
2014年 | 76篇 |
2013年 | 103篇 |
2012年 | 93篇 |
2011年 | 118篇 |
2010年 | 96篇 |
2009年 | 87篇 |
2008年 | 103篇 |
2007年 | 128篇 |
2006年 | 116篇 |
2005年 | 93篇 |
2004年 | 77篇 |
2003年 | 79篇 |
2002年 | 99篇 |
2001年 | 59篇 |
2000年 | 83篇 |
1999年 | 79篇 |
1998年 | 63篇 |
1997年 | 68篇 |
1996年 | 72篇 |
1995年 | 66篇 |
1994年 | 39篇 |
1993年 | 46篇 |
1992年 | 41篇 |
1991年 | 56篇 |
1990年 | 48篇 |
1989年 | 47篇 |
1988年 | 51篇 |
1987年 | 46篇 |
1986年 | 41篇 |
1985年 | 37篇 |
1984年 | 41篇 |
1983年 | 62篇 |
1982年 | 57篇 |
1981年 | 50篇 |
1980年 | 66篇 |
1979年 | 35篇 |
1978年 | 34篇 |
1977年 | 35篇 |
1976年 | 21篇 |
1974年 | 22篇 |
1973年 | 19篇 |
1966年 | 22篇 |
排序方式: 共有3137条查询结果,搜索用时 15 毫秒
1.
2.
Regan E. Giesinger Adrianne R. Bischoff Patrick J. McNamara 《Congenital heart disease》2019,14(2):311-316
Ligation of a hemodynamically significant ductus arteriosus results in significant changes in loading conditions which have predictable consequences. Postligation cardiac syndrome, defined as hypotension requiring inotropic support and failure of oxygenation and ventilation, may occur 6‐12 hours following ligation due to left ventricular systolic and diastolic failure, respectively. Afterload is the primary driver of this decompensation. In this review, we describe the pathophysiological changes in loading conditions associated with postligation cardiac syndrome and other contributors to cardiovascular dysfunction following ductal ligation. We present strategies for perioperative optimization and a physiology‐based algorithm for postoperative management guided by targeted neonatal echocardiography. The use of these strategies to reduce the frequency of postligation deterioration may be an avenue to improve outcomes for neonates in this vulnerable patient population. 相似文献
3.
Aoife De Brún Liran Shan Áine Regan Áine McConnon Patrick Wall 《Health communication》2016,31(10):1235-1241
The 2008 dioxin crisis occurred as a result of contamination of Irish pork. The event had significant implications for Ireland’s economy and the reputation of its agricultural industry, as well as raising concerns for human health. This study describes the results of a content analysis of Irish and UK newspaper coverage of the 2008 Irish dioxin crisis, as this is likely to provide insight into how public perceptions of this issue were shaped. Articles from 16 print publications were systematically sampled for the period December 2008 to February 2009. The resulting data set of 141 articles was examined using a coding protocol developed based on previous research and refined during piloting. Results indicated that the dioxin crisis was primarily portrayed by the media as an industry/economic crisis, dominant in 26.9% of articles in the sample. Within this dominant portrayal, the agricultural industry was frequently cited as being in crisis (42.6%); however, the implications of the crisis on the wider economic environment also received attention (17.7%). Differences between Irish and UK-based media were also examined, revealing that while the Irish media most frequently described the crisis in terms of its impact on the industry and economy, the UK media were more likely to portray the crisis as a risk to health. These dominant media messages and message framings have implications for the public understanding of the issue in each country and potential consequences regarding perception of the adequacy of existing food policy and regulatory oversight. 相似文献
4.
5.
Carel Bron Michel Wensing Jo LM Franssen Rob AB Oostendorp 《BMC musculoskeletal disorders》2007,8(1):107
Background
Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders. 相似文献6.
7.
Keith J Murphy Andrew G Foley Alan W O'connell Ciaran M Regan 《Neuropsychopharmacology》2006,31(1):90-100
Recent data suggest that Alzheimer's patients who discontinue treatment with cholinesterase inhibitors have a significantly delayed cognitive decline as compared to patients receiving placebo. Such observations suggest cholinesterase inhibitors to provide a disease-modifying effect as well as symptomatic relief and, moreover, that this benefit remains after drug withdrawal. Consistent with this suggestion, we now demonstrate that chronic administration of tacrine, nefiracetam, and deprenyl, drugs that augment cholinergic function, increases the basal frequency of dentate polysialylated neurons in a manner similar to the enhanced neuroplasticity achieved through complex environment rearing. While both drug-treated and complex environment reared animals continue to exhibit memory-associated activation of hippocampal polysialylated neurons, the magnitude is significantly reduced suggesting that such interventions induce a more robust memory pathway that can acquire and consolidate new information more efficiently. This hypothesis is supported by our findings of improved learning behavior and enhanced resistance to cholinergic deficits seen following either intervention. Furthermore, the level of enhancement of basal neuroplastic status achieved by either drug or environmental intervention correlates directly with improved spatial learning ability. As a combination of both interventions failed to further increase basal polysialylated cell frequency, complex environment rearing and chronic drug regimens most likely enhanced cognitive performance by the same mechanism(s). These findings suggest that improved memory-associated synaptic plasticity may be the fundamental mechanism underlying the disease modifying action of drugs such as cholinesterase inhibitors. Moreover, the molecular and cellular events underpinning neuroplastic responses are identified as novel targets in the search for interventive drug strategies for the treatment of neurodegenerative and neuropsychiatric disorders. 相似文献
8.
9.
Dr. Andrew G. Bostom M.D. Dr. Anne L. Hume Pharm.D. Dr. Charles B. Eaton M.D. Dr. Joseph P. Laurino Ph.D. Ms. Lisa R. Yanek B.A. Ms. Mary S. Regan B.S. Mr. William H. McQuade M.P.H. Dr. Wendy Y. Craig Ph.D. Ms. Gayle Perrone M.B.A. Dr. Paul F. Jacques Sc.D. 《Pharmacotherapy》1995,15(4):458-464
Study Objective . To determine the efficacy of high-dose ascorbate supplementation in lowering lipoprotein(a) [Lp(a)] levels in patients with premature coronary heart disease (CHD). Design . Randomized, double-blind, placebo-controlled trial. Setting . Outpatient clinic. Patients . Forty-four patients with documented premature CHD. defined as confirmed myocardial infarction and/or angiographically determined stenosis of 50% or greater in at least one major coronary artery before age 60 years. Interventions . Patients were block randomized on the basis of age, gender, and screening Lp(a) concentrations to receive ascorbate 4.5 g/day or placebo for 12 weeks. Measurements and Main Results . High-dose ascorbate was well tolerated and produced a marked elevation in mean plasma ascorbate levels (+1.2 mg/dl; p<0.001). Multiple linear regression analysis revealed no significant effect of supplementation on postintervention Lp(a) levels (p=0.39) in a model that included treatment group assignment, and baseline Lp(a) levels. Conclusions . Our findings do not support a clinically important lowering effect of high-dose ascorbate on plasma Lp(a) in patients with premature CHD. 相似文献
10.