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   1434篇
  免费   189篇
  国内免费   10篇
耳鼻咽喉   11篇
儿科学   74篇
妇产科学   10篇
基础医学   191篇
口腔科学   30篇
临床医学   130篇
内科学   338篇
皮肤病学   15篇
神经病学   133篇
特种医学   111篇
外科学   179篇
综合类   51篇
预防医学   185篇
眼科学   12篇
药学   88篇
肿瘤学   75篇
  2022年   14篇
  2021年   24篇
  2019年   24篇
  2018年   28篇
  2017年   11篇
  2016年   23篇
  2015年   21篇
  2014年   36篇
  2013年   47篇
  2012年   53篇
  2011年   71篇
  2010年   35篇
  2009年   31篇
  2008年   43篇
  2007年   62篇
  2006年   45篇
  2005年   74篇
  2004年   61篇
  2003年   74篇
  2002年   69篇
  2001年   54篇
  2000年   46篇
  1999年   35篇
  1998年   43篇
  1997年   35篇
  1996年   32篇
  1995年   28篇
  1994年   25篇
  1993年   23篇
  1992年   40篇
  1991年   30篇
  1990年   39篇
  1989年   31篇
  1988年   34篇
  1987年   25篇
  1986年   22篇
  1985年   25篇
  1984年   19篇
  1983年   11篇
  1982年   20篇
  1981年   12篇
  1980年   11篇
  1979年   10篇
  1978年   10篇
  1977年   15篇
  1975年   9篇
  1969年   9篇
  1968年   9篇
  1967年   8篇
  1966年   11篇
排序方式: 共有1633条查询结果,搜索用时 171 毫秒
901.
OBJECTIVE: The appropriate management of unruptured intracranial aneurysms depends on a complete understanding of their natural history and on the risks and efficacy of treatment options. There is little current data on the risks of endovascular therapy for these aneurysms. The aim of this study was to assess outcome of endovascular treatment of unruptured intracranial aneurysms. METHOD: A retrospective analysis was performed on all unruptured aneurysms treated by Guglielmi detachable (GD) coils at this institution from 1994 to 2000. RESULTS: Seventy three unruptured aneurysms were treated in 62 patients. There were 52 female and 10 male patients, with a median age of 55.7 years. Clinical background was: subarachnoid haemorrhage due to rupture of an additional aneurysm (40), headache (4), third nerve palsy (four), familial (four), and incidental (10). There were 14 technical failures with no clinical sequelae. Four procedural complications occurred (5.5%, 95% confidence interval (95% CI) 0.3% to 10.9%). One patient had temporary clinical sequelae (1.4%, 95% CI 0% to 2.7%); 79% of treated aneurysms had stable occlusions at follow up, 10.5% showed improved occlusion grade, 10.5% showed some recurrence, and three patients have required retreatment. Follow up modified Glasgow outcome scores were grade 1, 71%; grade 2, 18%; grade 3, 3%; grade 4, 3%. There were no deaths or haemorrhages during the follow up period. Two patients died as a result of complications from subarachnoid haemorrhage. CONCLUSION: The endovascular treatment of patients with unruptured aneurysms is safe with few clinical or procedural complications. Poor outcomes were only seen in those patients who presented with subarachnoid haemorrhage due to rupture of an aneurysm at another site.  相似文献   
902.
There is significant interest amongst neuroscientists in sharing neuroscience data and analytical tools. The exchange of neuroscience data and tools between groups affords the opportunity to differently re-analyze previously collected data, encourage new neuroscience interpretations and foster otherwise uninitiated collaborations, and provide a framework for the further development of theoretically based models of brain function. Data sharing will ultimately reduce experimental and analytical error. Many small Internet accessible database initiatives have been developed and specialized analytical software and modeling tools are distributed within different fields of neuroscience. However, in addition large-scale international collaborations are required which involve new mechanisms of coordination and funding. Provided sufficient government support is given to such international initiatives, sharing of neuroscience data and tools can play a pivotal role in human brain research and lead to innovations in neuroscience, informatics and treatment of brain disorders. These innovations will enable application of theoretical modeling techniques to enhance our understanding of the integrative aspects of neuroscience. This article, authored by a multinational working group on neuroinformatics established by the Organization for Economic Co-operation and Development (OECD), articulates some of the challenges and lessons learned to date in efforts to achieve international collaborative neuroscience.  相似文献   
903.
This article reviews the rapidly changing concepts related to the pathophysiology of major psychiatric disorders. The current era is an exciting one for psychiatric research and the rapidity with which advances are being made is a source of hope to patients with these disorders and for society.  相似文献   
904.
There are nearly 43,000 hip replacements and 33,000 knee replacements performed each year in the United Kingdom. Many of these require a blood transfusion. However, there has been increased public concern about the safety of blood transfusion and various techniques are used to decrease the need for allogenic transfusion. Postoperative blood salvage and reinfusion is one of them. We studied 186 consecutive patients who underwent unilateral uncemented hip or knee arthroplasty. Ninety-four had re-infusion drains and 92 had suction drains. We have compared the allogenic transfusion requirements for the two groups. We have analyzed patient and operative factors to determine whether they are predictive for risk of allogenic blood transfusion. Cost analysis was performed to determine whether the use of a re-infusion drain is a cost effective technique. Re-infusion drains significantly decreased the requirements for allogenic blood transfusion (p = 0.001). Twenty-one percent of the re-infusion drain group and 45.7 % of the suction drain group required allogenic blood transfusion. The only preoperative factor that determined whether the patient required allogenic blood transfusion was pre-operative haemoglobin. We found that age, gender, type of surgery (hip replacement or knee replacement) and whether the patient had tourniquet or not (in knee replacement) did not alter the requirements for allogenic blood transfusion. The mean transfusion costs were slightly less for re-infusion drain group (? 182.70 per patient for re-infusion drain group and ? 196.75 per patient for suction drain group, p = 0.009). The hospital stay was also significantly reduced (11.0 days for re-infusion drain group as opposed to 12.6 days for suction drain group (p = 0.0248). Based on these findings, re-infusion drains appear as a cost effective means of reducing the requirement for allogenic blood transfusion following primary hip and knee arthroplasty.  相似文献   
905.
The apparent sensitivities of several bacterial pathogens to tetracyclines varied by up to 128-fold with the medium content of Fe, but not of other metals. The effect of Fe was independent of superoxide dismutase activity and of intracellular Fe, but accumulation of tetracyclines was blocked in high-Fe medium. Thus, synergistic suppression of bacterial growth in the presence of a low Fe concentration and tetracyclines arises because of elevated antibiotic accumulation.  相似文献   
906.
A total of 40 patients with limb amputations were included in the present study aimed at evaluating the psychological status of amputees. All patients filled a specially designed proforma and the following psychological questionnaires: General Health Questionnaire, Carroll Rating Scale for Depression, State-Trait Anxiety Inventory, Michigan Alcoholism Screening Test and Disability Assessment Questionnaire. Analysis of the results showed that 29 (72.5%) of the amputees had psychiatric disorders and this number had reduced to 20 (50%) after therapy. The difference was statistically significant. Psychiatric treatment also resulted in a statistically significant reduction in level of depression as measured by Carroll Rating scale for Depression. The amputees had the highest score on vocational subscale of Dysfunction Analysis Questionnaire. Short term psychiatric treatment was found to be very useful in treating psychiatric morbidity and depression in amputees.Key Words: Amputees, Depression, Psychiatric morbidity  相似文献   
907.
An outbreak of influenza occurred at the end of the 2001-2 winter season in a highly-vaccinated, semi-enclosed, religious community. On the basis of retrospective self reporting, 43% met the case definition (151/350) and 81% (25/31) of throat swabs from cases were polymerase chain reaction (PCR) -positive for influenza A (H3N2). The risk of developing influenza in people aged 65 or more was lower than that of children aged 2 years and under (odds ratio 0.1, 95% confidence interval 0.02 to 0.38). The risk of developing symptoms of influenza was not significantly different between people who had been vaccinated in the United Kingdom and those who had not been vaccinated (OR 1.14, CI 0.41 to 3.14). Chronic disease was an independent risk factor for developing symptoms of influenza (OR 1.9, CI 1 to 3.63). Timing of the outbreak, the age structure and mode of communal living may have influenced the efficacy of the influenza vaccine, which was well matched to circulating strains at the time of the outbreak. It is important to consider the diagnosis of influenza even in a highly-vaccinated community.  相似文献   
908.
Jacobs R  Goddard M 《Lancet》2004,364(9443):1400-1400
  相似文献   
909.
Animal studies suggest that endothelin A (ETA) receptor antagonism and angiotensin-converting enzyme (ACE) inhibition may be synergistic. This interaction and the role of ETB receptors and endothelial mediators were investigated in terms of systemic and renal effects in humans in two studies. In one study, six subjects received placebo, the ETA receptor antagonist BQ-123 alone, and BQ-123 in combination with the ETB receptor antagonist BQ-788 after pretreatment with the ACE inhibitor enalapril (E) or placebo. In the other, six subjects who were pretreated with E received placebo, BQ-123, and BQ-123 with concomitant inhibition of nitric oxide (NO) synthase or cyclo-oxygenase (COX). Both were randomized, double-blind, crossover studies. Mean arterial pressure was reduced by BQ-123, an effect that was doubled during ACE inhibition (mean area under curve +/- SEM; BQ-123, -2.3 +/- 1.8%; BQ-123+E, -5.1 +/- 1.1%; P < 0.05 versus placebo). BQ-123 increased effective renal blood flow (BQ-123, -0.1 +/- 2.4%; BQ-123+E, 10.9 +/- 4.2%; P < 0.01 versus BQ-123), reduced effective renal vascular resistance (BQ-123, -1.2 +/- 3.1%; BQ-123+E, -12.8 +/- 3.0%; P < 0.01 versus placebo and versus BQ-123), and increased urinary sodium excretion markedly (BQ-123, 2.6 +/- 12.8%; BQ-123+E, 25.2 +/- 12.6%; P < 0.05 versus BQ-123, P < 0.01 versus placebo and versus E) only during ACE inhibition. These effects were abolished by both ETB receptor blockade and NO synthase inhibition, whereas COX inhibition had no effect. In conclusion, the combination of ETA receptor antagonism and ACE inhibition is synergistic via an ETB receptor-mediated, NO-dependent, COX-independent mechanism. The reduction of BP and renal vascular resistance and associated substantial natriuresis make this a potentially attractive therapeutic combination in renal disease.  相似文献   
910.
The purpose of this study was to assess the prevalence of TMD in a consecutive sample of 102 subjects from the Native American population living in an urban setting and 90 subjects living in a rural setting. The study utilized a clinical examination and standardized questionnaires. The sample age ranged from five to 84 years of age. The subjects were asked to estimate pain frequency, severity and daily pattern of jaw pain, difficulty in opening, joint clicking, and sleeping problems. Examination was performed on joint, masticatory, and cervical muscles, as well as occlusion. Data was collected and statistically analyzed. Statistically significant differences were found; however, the only statistically significant difference that might have clinical significance was more facial pain in the urban population.  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