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   1870篇
  免费   123篇
  国内免费   23篇
耳鼻咽喉   1篇
儿科学   75篇
妇产科学   3篇
基础医学   135篇
口腔科学   60篇
临床医学   282篇
内科学   826篇
皮肤病学   6篇
神经病学   43篇
特种医学   20篇
外科学   231篇
综合类   142篇
预防医学   98篇
眼科学   6篇
药学   60篇
中国医学   6篇
肿瘤学   22篇
  2023年   37篇
  2022年   43篇
  2021年   108篇
  2020年   126篇
  2019年   93篇
  2018年   105篇
  2017年   62篇
  2016年   37篇
  2015年   60篇
  2014年   120篇
  2013年   132篇
  2012年   74篇
  2011年   76篇
  2010年   56篇
  2009年   75篇
  2008年   67篇
  2007年   62篇
  2006年   61篇
  2005年   69篇
  2004年   55篇
  2003年   48篇
  2002年   44篇
  2001年   38篇
  2000年   33篇
  1999年   34篇
  1998年   23篇
  1997年   26篇
  1996年   23篇
  1995年   35篇
  1994年   17篇
  1993年   17篇
  1992年   18篇
  1991年   10篇
  1990年   15篇
  1989年   8篇
  1988年   10篇
  1987年   10篇
  1986年   15篇
  1985年   15篇
  1984年   12篇
  1983年   6篇
  1982年   8篇
  1981年   12篇
  1980年   4篇
  1979年   7篇
  1978年   3篇
  1977年   2篇
  1976年   2篇
  1975年   1篇
  1974年   2篇
排序方式: 共有2016条查询结果,搜索用时 328 毫秒
71.
BackgroundNonbacterial thrombotic endocarditis, or marantic endocarditis, is rare. Contemporary data on the etiology, echocardiographic evaluation, and management of nonbacterial thrombotic endocarditis are limited.MethodsA single-center retrospective cohort study was performed. Electronic medical records and echocardiographic records were searched for patients ages ≥18 years with a confirmed diagnosis of nonbacterial thrombotic endocarditis between January 1999 and November 2019. Demographic, echocardiographic, and management data were collected.ResultsOf 600,577 transthoracic echocardiograms (TTEs) and 89,264 transesophageal echocardiograms (TEEs), 42 patients had nonbacterial thrombotic endocarditis (mean age: 54 ± 14.5 years; 66.7% were female). The median duration of follow-up was 8.2 (interquartile range 3.3-24.4) months. Seventeen patients (40.5%) had malignancy, 33.3% had systemic lupus erythematosus, and 35.7% had antiphospholipid antibody syndrome. Stroke was the most common presentation (59.5%).TTE enabled the diagnosis in 19 cases (45.2%), compared with TEE, which identified the condition in 33 of 34 (97.1%) cases in which it was utilized. Three-dimensional echocardiography was performed in 17 TEEs. The most common valves involved were mitral (61.9%), and aortic (23.8%) valves. Thirty-two patients were managed with anticoagulation. Ten patients underwent surgery. Sixteen (38.1%) patients died, most of whom had a diagnosis of advanced malignancy.ConclusionIn a contemporary 20-year cohort, TTE and TEE played important roles in diagnosis, with superior diagnostic performance of TEE for nonbacterial thrombotic endocarditis. Mortality was high, and advanced malignancy portended a worse prognosis. Management in most cases was therapeutic anticoagulation. In select cases, surgery provided favorable outcomes.  相似文献   
72.
There have been few reports regarding infective endocarditis (IE) in patients with leukemia. In the first case, a 15‐year‐old girl with Down syndrome was diagnosed with acute lymphoblastic leukemia. On admission, methicillin‐sensitive Staphylococcus aureus (MSSA) was detected on blood culture. Echocardiography was performed because MSSA was detected repeatedly even after treatment. Vegetation in all of the atria and ventricles met the Duke criteria defining IE. She died of multiple organ failure 21 days after diagnosis. In the second case, an 11‐year‐old boy with acute myeloid leukemia underwent peripheral blood stem cell transplantation (PBSCT). He had fever 68 days after PBSCT, and methicillin‐resistant S. aureus (MRSA) was detected on blood culture. Echocardiography showed vegetation in the right atrium and ventricle. Daptomycin was administered for 7 weeks, and recurrence was not observed. IE should be considered when S. aureus bacteremia is documented even in patients with leukemia.  相似文献   
73.
Anatomic continuity between the anterior mitral leaflet and the aortic root may predispose those patients with aortic root pathology to functional changes of the mitral valve without any involvement of this valve. A 34-year-old man presented with aortic valve endocarditis. Transthoracic echocardiograpy showed severe aortic regurgitation with a large aortic root abscess. The anterior leaflet of the mitral valve was displaced towards the apex of the heart causing moderate mitral regurgitation. The patient underwent aortic valve replacement with reconstruction of the aortic annulus and ventriculoaortic continuity. This procedure alone restored the mitral valve structure and function without any need for intervention on the mitral valve. Aortic abscess is a serious complication of aortic valve endocarditis and may alter the function of other structures of the heart, especially the mitral valve. Restoration of aortic wall integrity and left ventricular – aortic continuity usually restores the mitral valve structure and function if the valve is unaffected by the infection. A decision on the mitral valve should be made following correction of the aortic pathology.  相似文献   
74.
PURPOSE: Staphylococcus aureus is a common cause of bacteremia and of native valve infective endocarditis. However, the risk of endocarditis in patients with a prosthetic valve who develop S. aureus bacteremia is unclear. The aim of this study was to define the risk of prosthetic valve endocarditis in patients with S. aureus bacteremia. SUBJECTS AND METHODS: All patients with a prosthetic valve or ring who developed S. aureus bacteremia during the 94-month study period were prospectively evaluated. The modified Duke criteria were used for the diagnosis of endocarditis. Patients were followed up for 12 weeks after the initial diagnosis of S. aureus bacteremia. RESULTS: The overall rate of definite prosthetic valve endocarditis among the study patients was 26/51 (51%). The risk of endocarditis was similar in patients with late (>or=12 months after valve implantation) vs. early S. aureus bacteremia (<12 months after prosthetic valve implantation) (50% vs. 52%, P=1.0), mitral vs. aortic prostheses (62% vs. 48%, P=0.24), and mechanical vs. bioprosthetic valves (62% vs. 44%, P=0.29). The 12-week mortality was higher among patients with definite vs. possible endocarditis (62% vs. 28%, P=0.019). CONCLUSION: In this investigation, approximately half of all patients with prosthetic valves who developed S. aureus bacteremia had definite endocarditis. The risk of endocarditis was independent of the type, location, or age of the prosthetic valve. The mortality of prosthetic valve endocarditis is high. All patients with a prosthetic valve who develop S. aureus bacteremia should be aggressively screened and followed for endocarditis.  相似文献   
75.
One hundred and six patients were analysed in order to assessthe effect of a more aggressive surgical policy in relationto the delays in diagnosis of infective endocarditis. The averageduration of symptoms before diagnosis was 9.7 weeks, even thoughthe patients had sought medical advice at a relatively earlystage of their illness (2.2 weeks). Three of the 29 (10.3%)patients who were treated surgically died and all three wereoperated upon five weeks or later after diagnosis. Seventy-sevenpatients did not have surgery and 15 died (19.5%). The outcome of surgical treatment for prosthetic valve endocarditiswas no worse than for native valve endocarditis. The mortalityof prosthetic valve endocarditis including early infectionswas 32% with medical but only 10% with surgical management comparedwith 14.5% and 10.5% in native valve endocarditis.Endocarditiscannot always be prevented but earlier diagnosis would reducemortality and prevent complications. When medical treatmentis failing then surgery should be considered early and urgentlyparticularly in staphylococcal infection or when large mobilevegetations are recognized; surgery is mandatory in fungal endocarditis.Earlier diagnosis would greatly reduce the current high incidenceof surgery, but that depends on a much heightened index of suspicionamongst both general practitioners and hospital physicians.  相似文献   
76.
Infective endocarditis (IE) is a rare condition which is associated with considerable morbidity and mortality. Almost 100 years ago, the links between endocarditis and procedures, particularly dental procedures, were postulated. Over 50 years ago the first guidelines recommending antibiotic prophylaxis (AP), with the aim of preventing IE developing after procedures, were proposed. However, there has only ever been circumstantial evidence in humans that AP prevents IE. The rarity of IE has made a randomised controlled clinical trial impractical to date. This article outlines the history of AP and reviews the evidence base for the use of AP to prevent IE.  相似文献   
77.
Objective To evaluate the efficacy of daptomycin in the treatment of left-sided infective endocarditis after failing to respond to vancomycin. Methods A retrospective analysis was conducted for 6 cases of infective endocarditis. Results Five of the six infective endocarditis patients were complicated with paravalvular abscess (artificial valve in 3 cases, native valve in 2 cases). Their disease deteriorated even under vancomycin treatment. Four of these patients received emergency valve replacement surgery but still febrile after operation. The antimicrobial therapy was switched to daptomycin at dose of 6 mg/kg daily for 2 to 4 weeks. The patients responded satisfactorily to daptomycin. The infection was controlled to some extent in the fifth patient after switching to daptomycin, but recurred later, and died suddenly on day 21 after reoperation. The sixth patient had infective endocarditis of native valve, and had treated with piperacillin-tazobactam for 2 weeks and vancomycin for 3 weeks, but responded poorly. The patient still had fever and enlarged vegetation. Switching to daptomycin reduced the body temperature and vegetation. Serum creatine kinase elevated moderately in one patient, and normal in the other 5 patients. No other apparent adverse reaction was reported. One patient died and the other five patient survived well for 18 months to 5 years. Conclusions Preliminary observation demonstrates the efficacy of daptomycin salvage treatment in a few cases of left-sided infective endocarditis after failing to respond to vancomycin therapy. © 2018, Editorial Department of Chinese Journal of Infection. All rights reserved.  相似文献   
78.

Summary

The coagulation system does not only offer protection against bleeding, but also aids in our defense against invading microorganisms. The hemostatic system and innate immunity are strongly entangled, which explains why so many infections are complicated by either bleeding or thrombosis. Staphylococcus aureus (S. aureus), currently the most deadly infectious agent in the developed world, causes devastating intravascular infections such as sepsis and infective endocarditis. During these infections S. aureus comes in close contact with the host hemostatic system and proves to be a master in manipulating coagulation. The coagulases of S. aureus directly induce coagulation by activating prothrombin. S. aureus also manipulates fibrinolysis by triggering plasminogen activation via staphylokinase. Furthermore, S. aureus binds and activates platelets and interacts with key coagulation proteins such as fibrin(ogen), fibronectin and von Willebrand factor. By manipulating the coagulation system S. aureus gains a significant advantage over the host defense mechanisms. Studying the interplay between S. aureus and the hemostatic system can therefore lead to new innovative therapies for battling S. aureus infections.
  相似文献   
79.

Purpose

The aim was to investigate the stability of cefazolin in elastomeric infusion devices.

Methods

Elastomeric devices (Infusor LV) that contain cefazolin (3 g/240 mL and 6 g/240 mL) were prepared and stored at 4°C for 72 hours and then at 35°C for 12 hours, followed by 25°C for 12 hours. An aliquot was withdrawn at predefined time points and analyzed for the concentration of cefazolin. Samples were also assessed for changes in pH, solution color, and particle content.

Findings

Cefazolin retained acceptable chemical and physical stability over the studied storage period and conditions.

Implications

These findings will allow the administration of cefazolin by the Infusor LV elastomeric device in the outpatient and remote settings.  相似文献   
80.
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