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   1378089篇
  免费   99764篇
  国内免费   1858篇
耳鼻咽喉   18096篇
儿科学   44443篇
妇产科学   37513篇
基础医学   204502篇
口腔科学   38827篇
临床医学   125061篇
内科学   276091篇
皮肤病学   30995篇
神经病学   110969篇
特种医学   49308篇
外国民族医学   266篇
外科学   192451篇
综合类   26356篇
现状与发展   3篇
一般理论   601篇
预防医学   115939篇
眼科学   30476篇
药学   100433篇
  7篇
中国医学   2632篇
肿瘤学   74742篇
  2021年   12031篇
  2019年   12880篇
  2018年   18088篇
  2017年   13097篇
  2016年   13800篇
  2015年   15833篇
  2014年   21282篇
  2013年   32346篇
  2012年   46037篇
  2011年   48981篇
  2010年   27610篇
  2009年   25555篇
  2008年   44910篇
  2007年   47944篇
  2006年   46902篇
  2005年   45967篇
  2004年   43654篇
  2003年   41622篇
  2002年   40146篇
  2001年   58867篇
  2000年   60400篇
  1999年   50605篇
  1998年   13848篇
  1997年   12562篇
  1996年   12917篇
  1995年   12148篇
  1994年   11283篇
  1992年   39150篇
  1991年   38460篇
  1990年   37167篇
  1989年   35868篇
  1988年   33186篇
  1987年   32522篇
  1986年   31028篇
  1985年   29181篇
  1984年   22256篇
  1983年   19417篇
  1982年   11483篇
  1979年   21218篇
  1978年   15564篇
  1977年   12957篇
  1976年   12027篇
  1975年   13041篇
  1974年   15828篇
  1973年   15645篇
  1972年   14765篇
  1971年   13815篇
  1970年   13038篇
  1969年   12311篇
  1968年   11465篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  相似文献   
32.
We report on 3 patients with pseudoathetosis, which are involuntary, slow, writhing movements due to loss of proprioception.  相似文献   
33.
Cell physiology and molecular biology typically follow a reductionistic approach in science. In the last decade, molecular principles and pathogenetic factors involved in the development of many diseases have been successfully discovered. Therefore, early biological concepts based on systemic and cybernetic thoughts have been largely overshadowed by these more recent molecular and pathogenetic factors. This review highlights discoveries on bone development and hypothalamic controlled feeding and eating behavior with a cybernetic and systemic perspective. Interestingly, ancient ideas on bone development and hypothalamic function are still reasonable considerations to embed new molecular discoveries into a systemic concept of principles organizing nature.  相似文献   
34.
35.
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   
36.
37.
38.
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   
39.
An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders.  相似文献   
40.
The aim of the current study was to investigate whether alterations in N-terminal pro brain natriuretic peptide (NT-proBNP) reflect changes in right ventricular structure and function in pulmonary hypertension patients during treatment. The study consisted of 30 pulmonary hypertension patients; 15 newly diagnosed and 15 on long-term treatment. NT-proBNP, right heart catheterisation and cardiac magnetic resonance imaging measurements were performed, at baseline and follow-up. There were no significant differences between newly diagnosed patients and those on treatment at baseline or follow-up with respect to NT-proBNP, haemodynamics and right ventricular parameters. Relative changes in NT-proBNP during treatment were correlated to the relative changes in right ventricular end-diastolic volume index (r = 0.59), right ventricular mass index (r = 0.62) and right ventricular ejection fraction (r = -0.81). N-terminal pro brain natriuretic peptide measurements reflect changes in magnetic resonance imaging-measured right ventricular structure and function in pulmonary hypertension patients. An increase in N-terminal pro brain natriuretic peptide over time reflects right ventricular dilatation concomitant to hypertrophy and deterioration of systolic function.  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