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   2489707篇
  免费   175283篇
  国内免费   10785篇
耳鼻咽喉   34202篇
儿科学   76576篇
妇产科学   69274篇
基础医学   341655篇
口腔科学   71071篇
临床医学   219030篇
内科学   493361篇
皮肤病学   57398篇
神经病学   200220篇
特种医学   99945篇
外国民族医学   651篇
外科学   384405篇
综合类   63174篇
现状与发展   20篇
一般理论   814篇
预防医学   185109篇
眼科学   56032篇
药学   181570篇
  71篇
中国医学   6671篇
肿瘤学   134526篇
  2018年   24206篇
  2016年   22374篇
  2015年   25488篇
  2014年   35261篇
  2013年   52048篇
  2012年   66168篇
  2011年   70634篇
  2010年   43270篇
  2009年   41808篇
  2008年   66160篇
  2007年   71328篇
  2006年   72561篇
  2005年   70335篇
  2004年   67224篇
  2003年   65423篇
  2002年   62951篇
  2001年   115999篇
  2000年   119754篇
  1999年   100946篇
  1998年   29240篇
  1997年   26481篇
  1996年   26660篇
  1995年   26164篇
  1994年   24378篇
  1993年   22713篇
  1992年   80906篇
  1991年   78563篇
  1990年   76226篇
  1989年   73597篇
  1988年   68368篇
  1987年   67348篇
  1986年   63923篇
  1985年   61143篇
  1984年   46378篇
  1983年   39120篇
  1982年   23994篇
  1981年   21787篇
  1980年   20423篇
  1979年   43002篇
  1978年   31013篇
  1977年   26580篇
  1976年   24197篇
  1975年   26331篇
  1974年   31214篇
  1973年   30101篇
  1972年   28372篇
  1971年   26467篇
  1970年   24640篇
  1969年   23443篇
  1968年   21940篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Sniff nasal inspiratory pressure (SNIP) measurement is a volitional noninvasive assessment of inspiratory muscle strength. A maximum of 10 sniffs is generally used. The purpose of the present study was to investigate whether the maximum SNIP improved after the tenth sniff. In total, 20 healthy volunteers and 305 patients with various neuromuscular and lung diseases were encouraged to perform 40 and 20 sniffs, respectively. The best SNIP among the first 10 sniffs was lower than the best SNIP among the next 10 sniffs in the healthy volunteers and patients. The SNIP improvement after the twentieth sniff was marginal. In conclusion, a learning effect persists after the tenth sniff. The current authors suggest using 10 additional sniffs when the best result of the first 10 sniffs is slightly below normal, or when sniff nasal inspiratory pressure is used to monitor a progressive decline in inspiratory muscle strength.  相似文献   
42.
Levels of the soluble form of the triggering receptor expressed on myeloid cells (sTREM)-1 are elevated in severe sepsis. However, it is not known whether sTREM-1 measurements can distinguish milder bacterial infections from noninfectious inflammation. The present authors studied whether serum sTREM-1 levels differ in community-acquired pneumonia, exacerbations of chronic obstructive pulmonary disease (COPD), asthma and controls, and whether sTREM-1 may be used as a surrogate marker for the need for antibiotics. Serum sTREM-1 levels in 150 patients with pneumonia, COPD and asthma exacerbations and 62 healthy controls were measured. Serum sTREM-1 levels were significantly elevated in pneumonia (median 295.2 ng x mL(-1)), COPD (280.3 ng x mL(-1)) and asthma exacerbations (184.0 ng x mL(-1)) compared with controls (83.1 ng x mL(-1)). Levels were higher in pneumonia and Anthonisen type 1 COPD exacerbations than in type 2 and 3 COPD and asthma exacerbations. The area under the receiver operating characteristics curve for sTREM-1 as a surrogate marker for the need for antibiotics was 0.77. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 were elevated predominantly in pneumonia and Anthonisen type 1 COPD exacerbations versus type 2 and 3 chronic obstructive pulmonary disease exacerbations, asthma and controls. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 has moderate but insufficient accuracy as a surrogate marker for the need for antibiotics in lower respiratory tract infections.  相似文献   
43.
44.
45.
Imaging     
  相似文献   
46.
47.
48.
Infections due to Penicillium species other than P.marneffei are rare. We identified a boy with X-linked chronic granulomatous disease (X-CGD) with a pulmonary nodule and adjacent rib osteomyelitis caused by Penicillium piceum. The only sign of infection was an elevated sedimentation rate. P. piceum was isolated by fine needle aspirate and from excised infected tissues. Surgical removal and one year of voriconazole treatment were very well tolerated and led to complete recovery. Microbiological, microscopic and molecular studies support the fungal diagnosis. P. piceum should be considered as a relevant pathogen in immunocompromised patients.  相似文献   
49.
50.
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