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   2998260篇
  免费   232645篇
  国内免费   5163篇
耳鼻咽喉   43508篇
儿科学   89154篇
妇产科学   78637篇
基础医学   422774篇
口腔科学   88158篇
临床医学   270538篇
内科学   584493篇
皮肤病学   61408篇
神经病学   247308篇
特种医学   119167篇
外国民族医学   941篇
外科学   461674篇
综合类   68289篇
现状与发展   2篇
一般理论   1156篇
预防医学   232786篇
眼科学   70601篇
药学   227375篇
  7篇
中国医学   5869篇
肿瘤学   162223篇
  2018年   29801篇
  2016年   25517篇
  2015年   28893篇
  2014年   41197篇
  2013年   62336篇
  2012年   84233篇
  2011年   88812篇
  2010年   52372篇
  2009年   50164篇
  2008年   84977篇
  2007年   90078篇
  2006年   91433篇
  2005年   88995篇
  2004年   85801篇
  2003年   82697篇
  2002年   81615篇
  2001年   145845篇
  2000年   151089篇
  1999年   127563篇
  1998年   34950篇
  1997年   31552篇
  1996年   31371篇
  1995年   30174篇
  1994年   28329篇
  1993年   26310篇
  1992年   101947篇
  1991年   98363篇
  1990年   95013篇
  1989年   91944篇
  1988年   84998篇
  1987年   83383篇
  1986年   78824篇
  1985年   75372篇
  1984年   56241篇
  1983年   47960篇
  1982年   28004篇
  1981年   24827篇
  1980年   23207篇
  1979年   52142篇
  1978年   36248篇
  1977年   30770篇
  1976年   28307篇
  1975年   30242篇
  1974年   37199篇
  1973年   35287篇
  1972年   33187篇
  1971年   30867篇
  1970年   29083篇
  1969年   27222篇
  1968年   24713篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Chronic obstructive pulmonary disease (COPD) is characterised by a local pulmonary inflammatory response to respiratory pollutants and by systemic inflammation. Tumour necrosis factor (TNF)-alpha has been implicated in systemic effects of COPD and operates by binding the p55 (R1) and p75 (R2) TNF-alpha receptors. To investigate the contribution of each TNF-alpha receptor in the pathogenesis of COPD, the present study examined the effects of chronic air or cigarette smoke (CS) exposure in TNF-alpha R1 knockout (KO) mice, TNF-alpha R2 KO mice and wild type (WT) mice. CS was found to significantly increase the protein levels of soluble TNF-alpha R1 (by four-fold) and TNF-alpha R2 (by 10-fold) in the bronchoalveolar lavage of WT mice. After 3 months, CS induced a prominent pulmonary inflammatory cell influx in WT and TNF-alpha R1 KO mice. In TNF-alpha R2 KO mice, CS-induced pulmonary inflammation was clearly attenuated. After 6 months, no emphysema was observed in CS-exposed TNF-alpha R2 KO mice in contrast to WT and TNF-alpha R1 KO mice. CS-exposed WT and TNF-alpha R1 KO mice failed to gain weight, whereas the body mass of TNF-alpha R2 KO mice was not affected. These current findings suggest that both tumour necrosis factor-alpha receptors contribute to the pathogenesis of chronic obstructive pulmonary disease, but tumour necrosis factor-alpha receptor-2 is the most active receptor in the development of inflammation, emphysema and systemic weight loss in this murine model of chronic obstructive pulmonary disease.  相似文献   
72.
73.
74.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
75.
76.
OBJECTIVE: To explore the presence and grade of denervation in three mimic muscles in facial nerve palsy. METHODS: The frontalis, orbicularis oculi (OO), and mentalis muscles were explored in 54 patients with Bell's palsy, after 30 days from the beginning of symptoms. Concentric needle electromyography, including fibrillation detection, was performed in the three muscles on the affected side. Compound muscle action potentials (CMAP) were recorded on both sides and a CMAP ratio was calculated from each muscle. The House-Brackman scale was used to assess the initial clinical evaluation and the follow-up until recovery. RESULTS: Fibrillation was recorded in 32 patients on the 30th day after the onset and was present in 100% of mentalis and in 90% of frontalis, but in only 34% of OO, a statistically significant difference. The grade of fibrillation in OO was also statistically lower from those in the other two muscles. The 32 patients were grouped according to the presence (A) or not (B) of fibrillation in OO. In group A, CMAP ratios (affected/normal side) did not differ significantly among the three muscles. However, in group B they were significantly greater in OO and frontalis than in mentalis. In between-group comparison, group B muscles had significantly higher CMAP ratios, lower degree of fibrillation, and better functional recovery. CONCLUSION: In facial palsy, the presence and grade of fibrillation in OO are lower than in frontalis and mentalis muscles and prognosis is more favorable for the non-fibrillating OO group of patients.  相似文献   
77.
A 27-year-old man was admitted with high fever and shivers eleven days after returning from vacation in Indonesia. Physical examination, laboratory values, abdominal ultrasound, and chest x-ray were not conclusive. All blood cultures yielded growth of Salmonella enterica serovar Typhi, and typhoid fever was diagnosed. Subsequently, the patient developed septic shock and pulmonary edema.In this case report epidemiological, clinical, and therapeutic aspects of typhoid fever are discussed with special emphasis on criteria for severe typhoid fever, which is treated with additional glucocorticoids.  相似文献   
78.
79.
80.
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