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   1975227篇
  免费   149314篇
  国内免费   4297篇
耳鼻咽喉   26066篇
儿科学   64987篇
妇产科学   54672篇
基础医学   289873篇
口腔科学   54255篇
临床医学   178245篇
内科学   387402篇
皮肤病学   45903篇
神经病学   154892篇
特种医学   74272篇
外国民族医学   531篇
外科学   294157篇
综合类   44733篇
现状与发展   5篇
一般理论   618篇
预防医学   151930篇
眼科学   45181篇
药学   142875篇
  3篇
中国医学   5270篇
肿瘤学   112968篇
  2019年   15719篇
  2018年   22407篇
  2017年   17094篇
  2016年   19369篇
  2015年   21566篇
  2014年   30253篇
  2013年   45042篇
  2012年   60722篇
  2011年   64387篇
  2010年   37966篇
  2009年   36144篇
  2008年   59572篇
  2007年   63340篇
  2006年   64319篇
  2005年   61667篇
  2004年   59431篇
  2003年   56476篇
  2002年   54670篇
  2001年   99834篇
  2000年   101950篇
  1999年   84377篇
  1998年   23175篇
  1997年   20585篇
  1996年   20825篇
  1995年   19795篇
  1994年   18014篇
  1993年   16853篇
  1992年   63963篇
  1991年   61771篇
  1990年   59638篇
  1989年   57502篇
  1988年   52530篇
  1987年   51245篇
  1986年   48182篇
  1985年   45692篇
  1984年   34366篇
  1983年   28963篇
  1982年   17130篇
  1981年   15171篇
  1979年   30516篇
  1978年   21468篇
  1977年   17965篇
  1976年   17098篇
  1975年   18069篇
  1974年   21453篇
  1973年   20670篇
  1972年   19384篇
  1971年   17745篇
  1970年   16947篇
  1969年   15602篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
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   
92.
93.
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   
94.
95.
96.
Rare kidney allograft recipients enjoy unaltered graft function years after interruption of their immunosuppressive treatment. To assess the extent to which this state of 'operational tolerance' (TOL) is specific to the graft and not the result of a global immunodeficiency, we analyzed the response of such patients following influenza vaccination. Hemagglutination inhibition titers and frequency of IFNgamma-secreting T cells were measured before 1 and 3 months after vaccination. The proportion of healthy volunteers (HV) responding to vaccine was significantly higher than that of immunosuppressed (IS) patients. Three 'TOL' patients presented a humoral response similar to that of HV, whereas the two others had a poor response, like the IS recipients. Although the small number of patients does not allow for definitive conclusions to be made, these data suggest that the status of tolerance may be heterogeneous, with some patients with a global immunodeficiency and others with an adapted response to vaccination.  相似文献   
97.
98.
目的:评价东部身体-智力-精神(EBMS)群体干预对进行体外受精(IVF)的中国妇女焦虑缓解的作用。设计:随机对照研究。机构:三级辅助生殖机构。受试者:227例接受第1个IVF周期治疗的妇女。干预:干预组(n=69)接受4次EBMS群体咨询,而对照组(n=115)无任何干预。主要观察指标:状态-特质焦虑问卷。结果:与对照组相比,干预组在干预后状态焦虑平均分显著下降。每组移植同样数目的卵子,但干预组没有明显更高妊娠率的倾向。  相似文献   
99.
100.
The pharmacokinetics (PK) of moxifloxacin in healthy white New Zealand rabbits was studied following intravenous (IV) and subcutaneous (SC) administration routes as well as a SC long‐acting poloxamer 407 gel formulation (SC‐P407). Moxifloxacin concentrations were determined by high‐performance liquid chromatography assay with fluorescence detection. Mean half‐life for IV, SC and SC‐P407 routes was 2.15, 5.41 and 11.09 h. Clearance value after IV dosing was 0.78 l/kg/h. After SC administration, the mean absolute bioavailability was 117% and the Cmax was 1.61 ± 0.49 mg/l. After SC‐P407 administration, the bioavailability was 44% and the Cmax 1.83 was ±0.62 mg/l. No adverse effects were observed in any of the rabbits following IV, SC and SC‐P407 administration of moxifloxacin. Minimal inhibitory concentrations of moxifloxacin against different strains of Staphylococcus aureus from different european countries were used to compute the main pharmacodynamic (PD) surrogate markers of efficacy. The high tolerability of this SC‐P407 formulation and the favourable PK behaviour such as the long half‐life, acceptable bioavailability and excellent PK–PD ratios achieved indicate that it is likely to be effective in rabbits.  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