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   3096篇
  免费   301篇
  国内免费   27篇
耳鼻咽喉   48篇
儿科学   84篇
妇产科学   39篇
基础医学   302篇
口腔科学   241篇
临床医学   323篇
内科学   658篇
皮肤病学   139篇
神经病学   171篇
特种医学   182篇
外科学   492篇
综合类   95篇
现状与发展   30篇
预防医学   235篇
眼科学   24篇
药学   242篇
中国医学   14篇
肿瘤学   105篇
  2024年   14篇
  2023年   190篇
  2022年   38篇
  2021年   76篇
  2020年   116篇
  2019年   78篇
  2018年   109篇
  2017年   96篇
  2016年   102篇
  2015年   100篇
  2014年   149篇
  2013年   164篇
  2012年   174篇
  2011年   186篇
  2010年   156篇
  2009年   147篇
  2008年   147篇
  2007年   172篇
  2006年   117篇
  2005年   99篇
  2004年   85篇
  2003年   77篇
  2002年   58篇
  2001年   61篇
  2000年   62篇
  1999年   73篇
  1998年   44篇
  1997年   57篇
  1996年   48篇
  1995年   39篇
  1994年   39篇
  1993年   38篇
  1992年   23篇
  1991年   24篇
  1990年   22篇
  1989年   35篇
  1988年   26篇
  1987年   26篇
  1985年   18篇
  1984年   8篇
  1983年   9篇
  1982年   11篇
  1981年   12篇
  1980年   17篇
  1979年   9篇
  1978年   10篇
  1977年   8篇
  1976年   13篇
  1975年   12篇
  1974年   8篇
排序方式: 共有3424条查询结果,搜索用时 468 毫秒
51.
There are no clear recommendations regarding cirrhotic cardiomyopathy (CC) evaluation in patients with pre-transplant liver cirrhosis. The roles of new methods, tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE) in the diagnosis and prognosis of cirrhotic cardiomyopathy remain controversial. We investigated the utility of TDI/STE parameters in cirrhotic cardiomyopathy diagnosis and also in predicting mortality in patients with liver cirrhosis. Left/right ventricular function was studied using conventional TDI (velocities) and STE (strain/strain rate). We assessed left ventricular diastolic dysfunction, graded into four new classes (I/Ia/II/III). Serum NTproBNP (N-terminal prohormone of brain natriuretic peptide), troponin I, β-crosslaps, QTc interval, arterial compliance and endothelial function were measured. Liver-specific scores (Child–Pugh, MELD, MELDNa) were computed. There was a 1-y follow-up visit to determine mortality. We observed resting biventricular diastolic myocardial dysfunction, not presently included in the definition of cirrhotic cardiomyopathy. We provided an improved characterization of cardiac dysfunction in patients with liver cirrhosis. This might change the current definition. However, the utility of STE/TDI parameters in predicting long-term mortality in patients with liver cirrhosis remains controversial.  相似文献   
52.
Odontology - This study aimed at evaluating the influence of glass-fiber post (GFP) relining with composites of different opacities on resin cement layer thickness (CLT), bond strength (BS) to root...  相似文献   
53.
54.
55.
Multidrug-resistant Acinetobacter baumannii poses a tremendous challenge to traditional antibiotic therapy. Due to the crucial role of iron in bacterial physiology and pathogenicity, we investigated iron metabolism as a possible target for anti-A. baumannii chemotherapy using gallium as an iron mimetic. Due to chemical similarity, gallium competes with iron for binding to several redox enzymes, thereby interfering with a number of essential biological reactions. We found that Ga(NO3)3, the active component of an FDA-approved drug (Ganite), inhibits the growth of a collection of 58 A. baumannii strains in both chemically defined medium and human serum, at concentrations ranging from 2 to 80 μM and from 4 to 64 μM, respectively. Ga(NO3)3 delayed the entry of A. baumannii into the exponential phase and drastically reduced bacterial growth rates. Ga(NO3)3 activity was strongly dependent on iron availability in the culture medium, though the mechanism of growth inhibition was independent of dysregulation of gene expression controlled by the ferric uptake regulator Fur. Ga(NO3)3 also protected Galleria mellonella larvae from lethal A. baumannii infection, with survival rates of ≥75%. At therapeutic concentrations for humans (28 μM plasma levels), Ga(NO3)3 inhibited the growth in human serum of 76% of the multidrug-resistant A. baumannii isolates tested by ≥90%, raising expectations on the therapeutic potential of gallium for the treatment of A. baumannii bloodstream infections. Ga(NO3)3 also showed strong synergism with colistin, suggesting that a colistin-gallium combination holds promise as a last-resort therapy for infections caused by pan-resistant A. baumannii.  相似文献   
56.
57.
58.
59.
This study described the prevalence of adults with shortened dental arches (SDA) in Brazil, specifically assessing the differences of oral health‐related quality of life [the prevalence and severity of oral impacts on daily performance (OIDP)] by dentition status. We analysed data from the 2010 National Survey of Oral Health in Brazil, including home interviews and oral examinations. The assessment of SDA used two alternative definitions: having 3–5 natural occlusal units (OUs) in posterior teeth or having 4 OUs in posterior teeth. Both definitions included having intact anterior region and no dental prosthesis. The analysis was weighted, and a complex sampling design was used. Negative binomial regression models assessed associations as adjusted for socio‐demographic conditions and dental outcomes. A total of 9779 adults (35–44 years old) participated in the study. A non‐negligible proportion had SDA: 9·9% and 3·8% for the first and second definition, respectively. Individuals with SDA (first definition) ranked higher in OIDP prevalence [count ratio (CR) 1·22; 1·09–1·36, 95% confidence interval (CI)] and severity (CR = 1·43; 1·19–1·72, 95% CI) than those with more natural teeth. This difference was not statistically significant when adjusted for socio‐demographic and dental covariates: OIDP prevalence (CR = 1·04; 0·92–1·17, 95% CI) and severity (CR = 1·09; 0·91–1·30, 95% CI). Analogous results were obtained when the second definition of SDA was adopted. These findings suggest that a considerable contingent of adults may function well without dental prostheses, despite having several missing teeth. This conclusion challenges the traditional approach of replacing any missing tooth and instructs the allocation of more dental resources to preventive, diagnostic and restorative services.  相似文献   
60.
The evaluation of gastrointestinal function in diabetic patients   总被引:2,自引:0,他引:2  
Nowadays,anumberofoptionsareavailablefortheasesmentofgastricmotorfunction.Thus,aglobalevaluationofgastricmotorfunctionmaybeob...  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