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   1428885篇
  免费   124700篇
  国内免费   3849篇
耳鼻咽喉   21225篇
儿科学   46740篇
妇产科学   37737篇
基础医学   195797篇
口腔科学   36681篇
临床医学   144956篇
内科学   296313篇
皮肤病学   34669篇
神经病学   118483篇
特种医学   53431篇
外国民族医学   266篇
外科学   219653篇
综合类   26432篇
现状与发展   74篇
一般理论   596篇
预防医学   113257篇
眼科学   31704篇
药学   95559篇
  8篇
中国医学   2070篇
肿瘤学   81783篇
  2021年   12619篇
  2019年   12443篇
  2018年   20824篇
  2017年   17466篇
  2016年   19367篇
  2015年   21202篇
  2014年   32993篇
  2013年   42873篇
  2012年   44349篇
  2011年   47057篇
  2010年   33623篇
  2009年   36219篇
  2008年   44868篇
  2007年   46111篇
  2006年   47806篇
  2005年   44577篇
  2004年   42096篇
  2003年   39537篇
  2002年   38357篇
  2001年   59754篇
  2000年   59953篇
  1999年   51267篇
  1998年   16998篇
  1997年   15561篇
  1996年   15903篇
  1995年   14986篇
  1994年   12996篇
  1993年   12016篇
  1992年   39575篇
  1991年   39092篇
  1990年   37524篇
  1989年   36408篇
  1988年   33700篇
  1987年   32923篇
  1986年   31396篇
  1985年   29562篇
  1984年   22635篇
  1983年   19801篇
  1982年   12015篇
  1979年   21296篇
  1978年   15796篇
  1977年   13243篇
  1976年   12151篇
  1975年   13101篇
  1974年   15870篇
  1973年   15633篇
  1972年   14828篇
  1971年   13773篇
  1970年   13031篇
  1969年   12152篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Contour defects resulting in deformity caused by lack of tissue can be improved by conventional surgery using autologous tissue, but there is always a donor site morbidity. Integra has been available since the early 1980's for use in acute burns and more recently in reconstruction. It has been shown histologically to act as a tissue regeneration template. The regenerated dermis is buried under an autologous thin split-skin graft. In this study, the principle of burying Integra (without the silicone layer) has been applied to deep tissue defects in 12 reconstructive cases. Such regenerated tissues survive at least 3 years after burying. Modification to the technique to avoid visible edges are being developed.  相似文献   
72.
Summary The third-stage larvae of Daniconema anguillae Moravec et K?ie, 1987 are found in the eels fins caught from Dringis Lake (Lithuanian National park). The morphology of these larvae is briefly described.  相似文献   
73.
74.
75.
OBJECTIVE: To evaluate the effect of statins on aneurysm growth in a group of consecutive patients under surveillance for infrarenal aortic aneurysms (AAA). MATERIALS AND METHODS: All patients (59 statin users, 91 non-users) under surveillance between January 2002 and August 2005 with a follow-up for aneurysm growth of at least 12 months and a minimum of three diameter evaluations were retrospectively included in the analysis. Multiple regression analysis, weighted with the number of observations, was performed to test the influence of statins on AAA growth rate. RESULTS: During a median period of 3.1 (1.1-13.1) years the overall mean aneurysm growth rate was 2.95+/-2.8 mm/year. Statin users had a 1.16 mm/year lower AAA growth rate compared to non-users (95% CI 0.33-1.99 mm/year). Increased age was associated with a slower growth (-0.09 mm/year per year, p = 0.003). Female gender (+1.82 mm/year, p = 0.008) and aneurysm diameter (+0.06 mm/year per mm, p = 0.049) were associated with increased AAA growth. The use of non-steroidal anti-inflammatory drugs, chronic lung disease, or other cardiovascular risk factors were not independently associated with AAA growth. CONCLUSIONS: Statins appear to be associated with attenuation of AAA growth, irrespective of other known factors influencing aneurysm growth.  相似文献   
76.
77.
Lymphocyte-predominant Hodgkin’s lymphoma (LPHL) differs in histologic and clinical presentation from classical Hodgkin’s lymphoma (cHL). Treatment of LPHL patients using standard Hodgkin’s lymphoma protocols leads to complete remission in more than 95% of patients. Survival and freedom from treatment failure are substantially worse in advanced-stage patients than for early-stage patients. Thus, patients in advanced stages and those in early stages with unfavorable risk factors should be treated similar to those with cHL. In contrast, patients with early-stage LPHL without risk factors might be sufficiently treated with reduced-intensity programs having less severe adverse effects. As a result, treatment of early LPHL is rather heterogeneous, including radiotherapy using extended-fleld technique, involved-fleld radiotherapy (IF-RT), combined-modality treatment, and, more recently, monoclonal antibodies. Watch-and-wait strategy plays an important role in pediatric oncology, to avoid adverse effects associated with therapy. IF-RT seems to be emerging as a treatment of choice for patients with stage IA LPHL; most larger study groups, such as the German Hodgkin Study Group and the European Organisation for Research and Treatment of Cancer, have adopted IF-RT as the treatment of choice for these patients.  相似文献   
78.
目的:通过16例经内窥镜及病理证实为Barrett食管的钡餐检查表现,初步探讨Barrett食管及其并发症放射学检查的意义。方法:回顾性分析16例Barrett食管的内窥镜和气钡检查的记录及表现,着重探讨气钡检查的X线表现。结果:食管内窥镜和组织学检查全部病例均有炎症改变,其他可见胃食管反流、食管溃疡和食管腺癌。放射学钡餐检查结果:Barrett食管炎4例,Barrett食管溃疡7例,Barrett食管癌5例。结论:Barrett食管及其并发症至今无明确放射学征象,改进对“Z”线的检查技术和方法,有可能提高其发现率。钡餐发现胃食管反流、食管裂孔疝同时并发食管炎、食管溃疡及食管癌者均应考虑到本症的可能。  相似文献   
79.
80.
There is increasing evidence that the assessment of eosinophilic airway inflammation using induced sputum and measurement of airway hyperresponsiveness provides additional, clinically important information concerning asthma control. The aim of this study was to directly compare the effects of different treatments on these markers in patients with asthma and persistent symptoms, despite the use of low-dose inhaled corticosteroids. A double-blind four-way crossover study was performed, which compared a 1-month treatment with budesonide 400 mug b.i.d., additional formoterol, additional montelukast and placebo in 49 patients with uncontrolled asthma despite budesonide 100 mug b.i.d., with each treatment separated by a 4-week washout period. The change in sputum eosinophil count with formoterol (2.4 to 3.8% change, 0.6-fold reduction, 95% confidence interval (CI) 0.5-0.9) differed significantly from placebo (2.8 to 2.5% change, 1.1-fold reduction, 95% CI 0.7-1.6) and high-dose budesonide (2.7 to 1.6% change, 1.6-fold reduction, 95% CI 1.2-2.2). The effects of montelukast did not differ from placebo. The changes in methacholine airway responsiveness were small and did not differ between treatments. High-dose budesonide had the broadest range of beneficial effects on other outcomes, including symptom scores, morning peak expiratory flow and forced expiratory volume in one second. In conclusion, treatment given in addition to low-dose inhaled corticosteroids results in modest benefits. Formoterol and high-dose budesonide have contrasting effects on eosinophilic airway inflammation.  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