全文获取类型
收费全文 | 4003篇 |
免费 | 310篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 127篇 |
妇产科学 | 205篇 |
基础医学 | 574篇 |
口腔科学 | 112篇 |
临床医学 | 467篇 |
内科学 | 644篇 |
皮肤病学 | 27篇 |
神经病学 | 325篇 |
特种医学 | 105篇 |
外科学 | 546篇 |
综合类 | 73篇 |
一般理论 | 1篇 |
预防医学 | 411篇 |
眼科学 | 112篇 |
药学 | 253篇 |
中国医学 | 9篇 |
肿瘤学 | 311篇 |
出版年
2021年 | 55篇 |
2020年 | 36篇 |
2019年 | 52篇 |
2018年 | 59篇 |
2017年 | 31篇 |
2016年 | 50篇 |
2015年 | 42篇 |
2014年 | 64篇 |
2013年 | 133篇 |
2012年 | 172篇 |
2011年 | 161篇 |
2010年 | 103篇 |
2009年 | 91篇 |
2008年 | 155篇 |
2007年 | 170篇 |
2006年 | 152篇 |
2005年 | 132篇 |
2004年 | 151篇 |
2003年 | 137篇 |
2002年 | 118篇 |
2001年 | 117篇 |
2000年 | 117篇 |
1999年 | 95篇 |
1998年 | 41篇 |
1996年 | 36篇 |
1995年 | 40篇 |
1994年 | 40篇 |
1992年 | 121篇 |
1991年 | 109篇 |
1990年 | 116篇 |
1989年 | 94篇 |
1988年 | 94篇 |
1987年 | 109篇 |
1986年 | 64篇 |
1985年 | 104篇 |
1984年 | 76篇 |
1983年 | 71篇 |
1982年 | 42篇 |
1981年 | 42篇 |
1980年 | 50篇 |
1979年 | 85篇 |
1978年 | 54篇 |
1977年 | 34篇 |
1975年 | 31篇 |
1974年 | 31篇 |
1972年 | 38篇 |
1971年 | 30篇 |
1970年 | 45篇 |
1968年 | 31篇 |
1967年 | 36篇 |
排序方式: 共有4319条查询结果,搜索用时 11 毫秒
1.
Marie Warrer Petersen Tine Sylvest Meyhoff Marie Helleberg Maj-Brit Nørregaard Kjær Anders Granholm Carl Johan Steensen Hjortsø Thomas Steen Jensen Morten Hylander Møller Peter Buhl Hjortrup Mik Wetterslev Gitte Kingo Vesterlund Lene Russell Vibeke Lind Jørgensen Klaus Tjelle Thomas Benfield Charlotte Suppli Ulrik Anne Sofie Andreasen Thomas Mohr Morten H. Bestle Lone Musaeus Poulsen Mette Friberg Hitz Thomas Hildebrandt Lene Surland Knudsen Anders Møller Christoffer Grant Sølling Anne Craveiro Brøchner Bodil Steen Rasmussen Henrik Nielsen Steffen Christensen Thomas Strøm Maria Cronhjort Rebecka Rubenson Wahlin Stephan Jakob Luca Cioccari Balasubramanian Venkatesh Naomi Hammond Vivekanand Jha Sheila Nainan Myatra Christian Gluud Theis Lange Anders Perner 《Acta anaesthesiologica Scandinavica》2020,64(9):1365-1375
Introduction
Severe acute respiratory syndrome coronavirus-2 has caused a pandemic of coronavirus disease (COVID-19) with many patients developing hypoxic respiratory failure. Corticosteroids reduce the time on mechanical ventilation, length of stay in the intensive care unit and potentially also mortality in similar patient populations. However, corticosteroids have undesirable effects, including longer time to viral clearance. Clinical equipoise on the use of corticosteroids for COVID-19 exists.Methods
The COVID STEROID trial is an international, randomised, stratified, blinded clinical trial. We will allocate 1000 adult patients with COVID-19 receiving ≥10 L/min of oxygen or on mechanical ventilation to intravenous hydrocortisone 200 mg daily vs placebo (0.9% saline) for 7 days. The primary outcome is days alive without life support (ie mechanical ventilation, circulatory support, and renal replacement therapy) at day 28. Secondary outcomes are serious adverse reactions at day 14; days alive without life support at day 90; days alive and out of hospital at day 90; all-cause mortality at day 28, day 90, and 1 year; and health-related quality of life at 1 year. We will conduct the statistical analyses according to this protocol, including interim analyses for every 250 patients followed for 28 days. The primary outcome will be compared using the Kryger Jensen and Lange test in the intention to treat population and reported as differences in means and medians with 95% confidence intervals.Discussion
The COVID STEROID trial will provide important evidence to guide the use of corticosteroids in COVID-19 and severe hypoxia.2.
3.
J. E. Hammond R. G. Berger T. S. Carey R. Rutledge T. J. Cleveland J. P. Kichak C. F. Ayscue 《Journal of medical systems》1991,15(3):257-267
Many hospitals today have implemented widely disparate information systems on mainframe and mini-computer hardware. The advent of network technology in hospitals has made it possible to access information in these systems. Unfortunately, the user interfaces to applications on these systems are unique and difficult to learn, which makes them unsuitable for use by clinical services. In this paper we describe the development of a Physician's Workstation which integrates information from multiple existing information systems and discuss how the workstation makes it possible to move from the departmental systems of the present to the computer-based medical record system of the future. 相似文献
4.
James M Stringham Billy R Hammond Billy R Wooten D Max Snodderly 《Optometry and vision science》2006,83(12):887-894
PURPOSE: Macular pigment (MP) filters short-wavelength light before it reaches the visual pigments. At peak absorbance (460 nm), transmission of light through MP can range from almost 100% transmission to as little as 3%. As a result of the uneven topographic distribution of MP, spatial nonuniformities in visual perception would result if the visual system did not compensate for filtering differences across the central retina. This study characterizes compensation for different densities of MP. METHODS: Sixteen young subjects (aged 24-40 years) with a wide range of MP density were studied. Increment thresholds were measured at 440 and 500 nm in the center of the fovea and at 6 degrees to 7 degrees eccentricity using conditions chosen to isolate the pi-1 mechanism. For six of the subjects, increment thresholds were also obtained for eccentricities of 1 degrees , 1.75 degrees , and 3 degrees . MP density was measured using heterochromatic flicker photometry at the same locations as the increment thresholds. RESULTS: Peak sensitivity of the short-wavelength pathway across the central retina was constant despite MP density differences as large as 1.0 log unit. CONCLUSIONS: These results suggest that the visual system increases gain of the S-cone pathway to offset light absorption by MP. 相似文献
5.
We examined several possible causes for the high incidence of poor sensory acuity in the limbs of 176 patients with moderate to severe peripheral vascular insufficiency. We investigated the relationships of diabetes, alcoholism, and smoking, as well as the severity of peripheral vascular disease, to the integrity of basic sensory modalities such as two-point discrimination and perception of light touch. The presence or absence of diabetes exerted the strongest effect on peripheral sensation. In patients who did not have diabetes, sensation in the limbs was most strongly affected by whether the patient was an alcoholic. Smoking did not have a significant effect on limb sensation. Among nondiabetic, nonalcoholic patients, there was a weak residual effect related to the severity of the peripheral vascular insufficiency. Even among these patients, however, systemic factors predominated in determining the loss of sensation. We also examined the extent to which loss of sensation might be related to the development of ulcers. Among patients who were not diabetic, there was a highly significant relationship between loss of sensation and the presence of limb ulceration. Surprisingly, however, there was no discernable relationship between the presence of ulcers in diabetic patients and the degree of loss of peripheral sensation. This result suggests that a large percentage of ulcers seen in diabetic patients are not of neurogenic origin. 相似文献
6.
John D Bisognano Joann Lindenfeld Elizabeth Hammond Lawrence S Zisman 《The Journal of heart and lung transplantation》2005,24(3):355-358
The etiology of cardiac allograft vasculopathy is not known, but may be preceded by both endothelial cell and smooth muscle dysfunction of the epicardial coronary arteries. We here report a case of acute, reversible coronary artery vasospasm which caused a myocardial infarction in a cardiac transplant recipient. The patient had a complex post-transplant course, including an episode of severe vascular rejection several months before this presentation. Interestingly, the event was captured in its early stages because the patient presented with chest pain: a rare event because of the denervation of the transplanted heart. Our ability to document the etiology of this patient's myocardial infarction supports the concept that cardiac allograft vasculopathy is a progressive disease that, in its early stages, may include a reversible component of abnormal vasoreactivity. 相似文献
7.
8.
Cognitive evoked potentials and disorders of recent memory 总被引:1,自引:0,他引:1
P3 potentials evoked by spoken words were recorded from seven patients with disorders of recent memory and seven age-matched controls. Inclusion criteria included a clearly identifiable P3 to pure tone stimuli. Absence or marked decrement of P3 to word stimuli was seen in the patients even though they could perform the word task. The results are consistent with an encoding disorder and failure in elaboration of information processing. 相似文献
9.
Kevin O'Brien Jean Wright Frances Conboy YeWeng Sanjie Nicky Mandall Stephen Chadwick Ivan Connolly Paul Cook David Birnie Mark Hammond Nigel Harradine David Lewis Cathy McDade Laura Mitchell Alison Murray Julian O'Neill Mike Read Stephen Robinson Dai Roberts-Harry Jonathan Sandler Ian Shaw 《American journal of orthodontics and dentofacial orthopedics》2003,124(3):234-43; quiz 339
This study evaluated the effectiveness of early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion. This multicenter trial was carried out in the United Kingdom. A total of 174 children, aged 8 to 10 years old, with Class II Division 1 malocclusion were randomly allocated to receive treatment with a Twin-block appliance or to an untreated, control group. Data were collected at the start of the study and 15 months later. Results showed that early treatment with Twin-block appliances resulted in reduction of overjet, correction of molar relationships, and reduction in severity of malocclusion. Most of this correction was due to dentoalveolar change, but some was due to favorable skeletal change. Early treatment with the Twin-block appliance is effective in reducing overjet and severity of malocclusion. The small change in the skeletal relationship might not be considered clinically significant. 相似文献
10.