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   2018767篇
  免费   125870篇
  国内免费   3531篇
耳鼻咽喉   27310篇
儿科学   65952篇
妇产科学   54582篇
基础医学   278200篇
口腔科学   52974篇
临床医学   171341篇
内科学   389806篇
皮肤病学   41736篇
神经病学   158871篇
特种医学   82398篇
外国民族医学   535篇
外科学   312584篇
综合类   40718篇
现状与发展   1篇
一般理论   497篇
预防医学   148676篇
眼科学   45053篇
药学   150065篇
  7篇
中国医学   4977篇
肿瘤学   121885篇
  2018年   39099篇
  2017年   30881篇
  2016年   34509篇
  2015年   19488篇
  2014年   26660篇
  2013年   39791篇
  2012年   59135篇
  2011年   75187篇
  2010年   50563篇
  2009年   42047篇
  2008年   70502篇
  2007年   75967篇
  2006年   57428篇
  2005年   56932篇
  2004年   55830篇
  2003年   54872篇
  2002年   51772篇
  2001年   94014篇
  2000年   96728篇
  1999年   81296篇
  1998年   21316篇
  1997年   19107篇
  1996年   19006篇
  1995年   17717篇
  1994年   16517篇
  1993年   15550篇
  1992年   61688篇
  1991年   59248篇
  1990年   58186篇
  1989年   55954篇
  1988年   51163篇
  1987年   49961篇
  1986年   47396篇
  1985年   44937篇
  1984年   32931篇
  1983年   27834篇
  1982年   15982篇
  1981年   13929篇
  1979年   29911篇
  1978年   20391篇
  1977年   17910篇
  1976年   16100篇
  1975年   18064篇
  1974年   21307篇
  1973年   20461篇
  1972年   19512篇
  1971年   18153篇
  1970年   17086篇
  1969年   16324篇
  1968年   14984篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease.  相似文献   
32.
33.
Setting goals to maintain hope.   总被引:3,自引:0,他引:3  
  相似文献   
34.
35.
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   
36.
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   
37.
38.
39.
40.
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