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:      
  示例: 沙坡头地区,人工植被区,变化  检索词用空格隔开表示必须包含全部检索词,用“,”隔开表示只需满足任一检索词即可!
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   1384074篇
  免费   80578篇
  国内免费   2783篇
耳鼻咽喉   17069篇
儿科学   44440篇
妇产科学   36936篇
基础医学   201483篇
口腔科学   36191篇
临床医学   133285篇
内科学   263058篇
皮肤病学   26672篇
神经病学   114594篇
特种医学   48705篇
外国民族医学   366篇
外科学   186145篇
综合类   29223篇
现状与发展   1篇
一般理论   523篇
预防医学   117521篇
眼科学   29533篇
药学   100321篇
  39篇
中国医学   3227篇
肿瘤学   78103篇
  2021年   11541篇
  2019年   12513篇
  2018年   16806篇
  2017年   12715篇
  2016年   13926篇
  2015年   15823篇
  2014年   21700篇
  2013年   33194篇
  2012年   45697篇
  2011年   48390篇
  2010年   27979篇
  2009年   25706篇
  2008年   44115篇
  2007年   46559篇
  2006年   46681篇
  2005年   45066篇
  2004年   42977篇
  2003年   40833篇
  2002年   39542篇
  2001年   61014篇
  2000年   62648篇
  1999年   52476篇
  1998年   14857篇
  1997年   13493篇
  1996年   13321篇
  1995年   12631篇
  1994年   11786篇
  1993年   11089篇
  1992年   41674篇
  1991年   40850篇
  1990年   39520篇
  1989年   37429篇
  1988年   34655篇
  1987年   33765篇
  1986年   32220篇
  1985年   30716篇
  1984年   23127篇
  1983年   19689篇
  1982年   11865篇
  1979年   20857篇
  1978年   14870篇
  1977年   12113篇
  1976年   11927篇
  1975年   12157篇
  1974年   14839篇
  1973年   14490篇
  1972年   13383篇
  1971年   12426篇
  1970年   11491篇
  1969年   10413篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
103.
104.
Ambient light affects pulse oximeters   总被引:1,自引:0,他引:1  
  相似文献   
105.
Clinical experience of phototherapy for non-haemolytic hyperbilirubinaemia in 3999 infants in Kandang Kerbau Hospital, Singapore, is documented. Phototherapy was most effective in extremely preterm infants with very low birth weight (gestation less than or equal to 32 weeks, birth weight less than or equal to 1500 g) and least effective in full term infants with very low birth weight (gestation greater than or equal to 37 weeks, birth weight less than or equal to 1500 g) and large preterm infants (gestation less than 37 weeks, birth weight greater than 2270 g). Overall, phototherapy was effective in almost all the infants, with a failure rate of only 2.00/1000 infants. No characteristic features common to all the failures could be detected. The bilirubin rebound was usually mild; repeat phototherapy was required in only 30 infants (7.50/1000), with the response to the second exposure comparable to that to the first. No infant required a third exposure. All the infants tolerated phototherapy well, none developing any illness that could be attributed to the treatment. This clinical experience shows that phototherapy for the treatment of nonhaemolytic hyperbilirubinaemia is effective and safe.  相似文献   
106.
107.
Pyomyositis occurs infrequently in temperate climates. The fulminating peracute form caused by group A Streptococcus is exceedingly rare. We present two children with streptococcal pyomyositis. One child was admitted in septic shock and required intensive supportive care during the acute stage of his illness. Persistent swelling and tenderness of his left thigh presented a diagnostic problem, which was eventually resolved with the aid of computerized tomography. Despite appropriate antibiotic therapy from the onset of illness, surgical debridement of the affected muscle was necessary. The second child presented with pyomyositis of the left paravertebral muscles and signs of incipient shock but did well on antibiotic therapy alone.  相似文献   
108.
In vitro studies established that neither cloth nor disposable diapers demonstrably contributed to the growth of Escherichia coli, Proteus vulgaris, Staphylococcus aureus, or Candida albicans when urine was present as a growth medium. In a clinical study of 166 children, the microbial skin flora of children with atopic dermatitis was compared with the flora of children with normal skin to determine the influence of diaper type. No biologically significant differences were detected between groups wearing disposable or cloth diapers in terms of frequency of isolation or log mean recovery of selected skin flora. Repeated isolation of S. aureus correlated with atopic dermatitis. The log mean recovery of S. aureus was higher in the atopic groups. The effects of each diaper type on skin microflora were equivalent in the normal and atopic populations.  相似文献   
109.
A crossover double-blind controlled trial was performed on 36 patients with rheumatoid arthritis to assess the necessity for serum salicylate monitoring in determining optimal dosage. There was no clinically or statistically significant increase in the clinical improvement of patients associated with serum monitoring but potentially toxic serum levels occurred without tinnitus when serum monitoring was not used.  相似文献   
110.
Extracellular 5-HT in the anterior hypothalamus/preoptic area (AH/POA) and caudate nucleus of the freely moving cat was measured using in vivo brain microdialysis. Administration of 8-OH-DPAT, a 5-HT1A receptor agonist that decreases 5-HT neuronal activity, decreased extracellular 5-HT in both brain areas. Extracellular 5-HT levels were also examined in relationship to the sleep-wake cycle, because previous data from our laboratory have indicated that behavioral state is the primary determinant of 5-HT neuronal discharge. As with 5-HT neuronal discharge, extracellular 5-HT was increased during active behavioral states and decreased during somnolent periods. These first two sets of findings confirm the ability of the microdialysis technique to measure physiological fluctuations in extracellular 5-HT levels and support the hypothesis that neuronal discharge is a major determinant of extracellular 5-HT levels. Levels of the 5-HT metabolite 5-hydroxyindole acetic acid (5-HIAA) in the AH/POA were also responsive to changes in behavioral state and administration of 8-OH-DPAT, though fluctuations in extracellular 5-HIAA were less robust and temporally delayed. Finally, extracellular 5-HT and 5-HIAA were examined in the AH/POA during fever induced by systemic injection of the synthetic pyrogen muramyl dipeptide. Previous data from our laboratory have indicated that 5-HT neuronal activity is unaffected by this manipulation, though 5-HT has been implicated specifically in thermoregulation. Pyrogen-induced hypothermia produced no specific change in 5-HT efflux, because any changes noted could be accounted for by behavioral state changes. These data are consistent with the hypothesis that the brain serotonergic system is closely linked to the sleep-wake-arousal cycle. However, extracellular 5-HT may be involved in thermoregulatory processes as part of a global role in modulating neuronal activity in coordination with the behavioral state of the animal.  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