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   581篇
  免费   25篇
  国内免费   6篇
耳鼻咽喉   9篇
儿科学   65篇
妇产科学   70篇
基础医学   74篇
口腔科学   34篇
临床医学   43篇
内科学   81篇
皮肤病学   34篇
神经病学   32篇
特种医学   23篇
外科学   69篇
综合类   3篇
一般理论   1篇
预防医学   9篇
眼科学   29篇
药学   18篇
中国医学   3篇
肿瘤学   15篇
  2024年   1篇
  2023年   6篇
  2022年   3篇
  2021年   14篇
  2020年   6篇
  2019年   19篇
  2018年   12篇
  2017年   18篇
  2016年   19篇
  2015年   19篇
  2014年   24篇
  2013年   34篇
  2012年   48篇
  2011年   56篇
  2010年   28篇
  2009年   22篇
  2008年   41篇
  2007年   54篇
  2006年   34篇
  2005年   47篇
  2004年   33篇
  2003年   23篇
  2002年   16篇
  2001年   3篇
  2000年   9篇
  1999年   6篇
  1998年   2篇
  1997年   5篇
  1996年   4篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1989年   1篇
排序方式: 共有612条查询结果,搜索用时 15 毫秒
21.
22.
23.
BACKGROUND: The purpose of the paper was to evaluate the indications of hospital admissions and complications of varicella infection in immunologically healthy children. METHODS: Between 1997 and 2001, patient records of children hospitalized due to varicella infection were reviewed. Incidence and clinical spectrum of complications and their distribution related to age and seasonal variations were analyzed. RESULTS: A total of 178 immunocompetent children were hospitalized for varicella complications during the study period. This resulted in a crude incidence of 6.3/100 000 population at risk. All hospital admissions were due to accompanying complications. The majority of complications occurred in preschool-age children with a median age of 3 years. No gender predominance was found. The most frequent complications were infectious complications, which were observed in 79 children (44%). Superinfections of the skin were present in 24 patients. Pneumonia was observed in 59 children: 49 had bacterial, 10 had viral pneumonia. Pyogenic arthritis was seen in two children and one had concomitant osteomyelitis. Group A beta-hemolytic streptococci were recovered from two patients with invasive bacterial infections. A total of 68 (38%) neurologic complications were observed. Cerebellar ataxia was present in 24, encephalitis was present in 17. Infectious complications occurred more frequently in younger children (median age: 2 years), whereas neurologic complications occurred at an older age (median age: 6 years). Hematologic complications were seen in nine children. There was a seasonal distribution of complications with a peak in January. CONCLUSION: Complications of varicella requiring hospitalization in immunocompetent children are more frequent than previously thought.  相似文献   
24.
Acquired protein S deficiency and lupus anticoagulant have been described in children with varicella who had purpura fulminans, disseminated intravascular coagulation or thrombosis. The aim of this study was to investigate the natural anticoagulants, hypercoagulability markers, other parameters of coagulation and fibrinolytic systems, and the presence of the lupus anticoagulant in otherwise healthy children with acute varicella infection. Blood samples were obtained from 17 children with varicella without thrombosis during acute varicella infection and 1 mo after onset. Coagulation tests included determinations of the prothrombin time, the activated partial thromboplastin time, the thrombin time, the thrombin antithrombin complex, the prothrombin fragment F 1 + 2, the tissue plasminogen activator, the plasminogen activator inhibitor-1, protein C activity and free protein S antigen. Antiphospholipid antibodies were determined in enzyme-linked immunosorbent assays. The mean free protein S concentration in the acute phase (0.63 ± 0.16 U/ml) was significantly lower than that of the concentration determined 1 mo later (0.82 ± 0.17 U/ml). The children with acquired free protein S deficiency also had a lupus anticoagulant. Elevated concentrations of the prothrombin fragment F 1 + 2, the thrombin antithrombin complex, D-Dimer, tissue plasminogen activator and plasminogen activator inhibitor-1 were detected in most of the children. Conclusion: There is a significantly increased prevalence of lupus anticoagulant, a significantly reduced plasma concentration of free protein S and elevations in coagulation and fibrinolytic parameters in otherwise healthy children with acute varicella infection.  相似文献   
25.
The prevalence of metallo-beta-lactamases (MBLs) produced by isolates of Pseudomonas aeruginosa and Acinetobacter baumannii and the activities of various antmicrobial combinations against MBL producer strains were investigated. During the period from June 2003 till July 2004, 120 P. aeruginosa and 9 A. baumannii nonduplicate isolates were obtained from burn wounds. Forty strains (37 P. aeruginosa, 3 A. baumannii) were selected because of resistance to carbapenems. Screening for MBL production was performed in the latter isolates by the combined disk method which depends on comparing the zones given by disks containing imipenem with and without ethylenediaminetetraacetic acid (EDTA). Of imipenem resistant P. aeruginosa strains, 21 and 1 of A. baumannii were found metallo-beta-lactamase producers. Disk approximation studies were then performed to test for in vitro activities of various antimicrobial combinations. For a total of 21 P. aeruginosa strains, synergy was demonstrated predominantly by ciprofloxacin in combination with ceftazidime and imipenem, by ofloxacin in combination with astreonam. Against MBL producer A. baumannii strain, synergy was detected only with imipenem-ofloxacin combination. None of the combinations were antagonistic. These results suggest that MBL producing P. aeruginosa and A. baumanni strains have been introduced into burn centers, and to prevent the further spread of MBL producers, it is essential for carbapenem resistant isolates to be screened for MBLs.  相似文献   
26.
27.
Background: Tissue-plasminogen activator is a key protein of fibrinolytic system. In recent years the relation between t-PA, its genetic polymorphisms and arterial or venous thrombosis were investigated in different populations. The aim of this study is to investigate the role of t-PA gene polymorphism in Turkish venous thromboembolism (VTE) patients.Methods: A case-control study was performed. We investigated the t-PA insertion/deletion (I/D) polymorphism in 93 VTE patients and 146 controls without VTE. Recurrent cases and documented risk factors for PTE were recorded.Results: Cases and controls did not differ with respect to the different t-PA genotypes. The prevalence of I allele was 44.1%, 44.5% in cases and controls respectively (OR = 0.95, 95% CI: 0.78–1.24, p > 0.05). Different t-PA genotypes had no effect on recurrent disease. No gender difference was observed with respect to the different t-PA genotypes. There was no significant difference for genotype frequency between PTE patients with documented risk factors and unprovoked cases.Conclusions: In conclusion there was no association between t-PA genotype and VTE in this group of Turkish population. It was also found that genotype frequencies for t-PA in both VTE and control subjects seems different from those reported from western part of the world.Abbreviated Abstract. The aim of this study is to investigate the role of t-PA gene polymorphism in Turkish VTE patients. We investigated 93 VTE patients and 146 controls without VTE. Cases and controls did not differ with respect to the different t-PA genotypes. The prevalence of I allele was 44.1%, 44.5% in cases and controls respectively (OR = 0.95, 95% CI: 0.78–1.24, p > 0.05). Different t-PA genotypes had no effect on recurrent disease. No gender difference was observed with respect to the different t-PA genotypes. There was no significant difference for genotype frequency between PTE patients with documented risk factors and unprovoked cases. In conclusion there was no association between t-PA genotype and VTE in this group of Turkish population. It was also found that genotype frequencies for t-PA in both VTE and control subjects seems different from those reported from western part of the world.  相似文献   
28.
Renal replacement lipomatosis (RRL) is the result of rare, usually unilateral, and severe atrophy and destruction of the renal parenchyma often caused by renal calculi. It may be associated with, sometimes, aging, atrophy, long-standing chronic inflammation and urinary infection, such as renal tuberculosis. We report magnetic resonance (MR) and computed tomography (CT) findings of our case, which has xanthogranulomatous pyelonephritis (XGP) and RRL additionally associated with nephrocutanous fistula.  相似文献   
29.
We carried out molecular deletion analysis on 142 patients with Duchenne/Becker muscular dystrophy which covered 25 exons of the dystrophin gene. We also evaluated the results by comparing with the clinical findings and examples in the literature. A deletion ratio of 63.7% was achieved. Exon 46 was the most frequently affected region. Interestingly we also observed four cases with muscle promoter (Mp) region deletions which have been rarely reported in the literature.  相似文献   
30.
Neural response telemetry (NRT) data from 63 subjects equipped with the Nucleus CI24M Cochlear Implant System generally exhibited little change over up to 4 years. Larger changes, when they occurred, were seen only within the first 15 months postoperatively, and these changes diminished over time. Intraoperative NRT data were generally stable enough to be used for assisting in the initial speech processor fitting sessions. It was not possible to predict changes in the subjective map threshold and comfortable loudness levels (T and C levels, respectively) based on observed changes in the NRT data. The long-term stability of the neural response amplitude and the neural response threshold, however, implies that NRT may be useful as a routine diagnostic tool to detect changes to the neural periphery over time.  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