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   2907828篇
  免费   244328篇
  国内免费   12946篇
耳鼻咽喉   40149篇
儿科学   91794篇
妇产科学   73082篇
基础医学   478895篇
口腔科学   78842篇
临床医学   260374篇
内科学   495836篇
皮肤病学   82668篇
神经病学   249600篇
特种医学   113476篇
外国民族医学   88篇
外科学   457117篇
综合类   88484篇
现状与发展   23篇
一般理论   2100篇
预防医学   249670篇
眼科学   66310篇
药学   196430篇
  22篇
中国医学   8686篇
肿瘤学   131456篇
  2022年   23028篇
  2021年   54782篇
  2020年   34931篇
  2019年   57943篇
  2018年   70084篇
  2017年   53246篇
  2016年   58511篇
  2015年   73262篇
  2014年   107332篇
  2013年   172382篇
  2012年   75912篇
  2011年   74291篇
  2010年   112591篇
  2009年   117932篇
  2008年   61569篇
  2007年   62409篇
  2006年   73916篇
  2005年   69594篇
  2004年   71825篇
  2003年   63070篇
  2002年   53295篇
  2001年   74214篇
  2000年   66299篇
  1999年   71772篇
  1998年   61934篇
  1997年   60417篇
  1996年   58215篇
  1995年   53686篇
  1994年   47852篇
  1993年   44810篇
  1992年   47967篇
  1991年   46324篇
  1990年   43919篇
  1989年   43928篇
  1988年   40803篇
  1987年   39960篇
  1986年   38012篇
  1985年   38888篇
  1984年   38561篇
  1983年   36099篇
  1982年   38113篇
  1981年   36352篇
  1980年   34363篇
  1979年   30952篇
  1978年   29761篇
  1977年   27762篇
  1976年   25504篇
  1975年   24165篇
  1974年   23884篇
  1973年   22663篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
In the brain of quaking and shiverer mutants, vitamin E content was normal when related to both wet weight and dry weight. When related to lipid extract, phosphorus, and polyunsaturated fatty acids, vitamin E was slightly increased only in the quaking mutant. In the sciatic nerve from trembler mutants, vitamin E was 134% of control values in the dry material, but normal in relation to wet weight. It was 260% in the lipid extract and 716% based on phosphorus. In relation to total fatty acids, there was a threefold increase in trembler mutants. Interestingly, it was increased approximately three times when related to 18∶2 n?6, 20∶4 n?6, and 20∶5 n?3, and seven times when related to 22∶6 n?3. The fact that the amount of vitamin E in fresh weight was normal, suggests that vitamin E plays a role in some nonmembrane material, such as the extracellular matrix or the basal lamina.  相似文献   
993.
994.
995.
996.
Normal seminal vesicles were studied histologically in 80, and by Feulgen’s cytophotometric method in 10 autopsied cases (males, 44–82 years of age). In every case large, hyperchromatic nuclei were found. By cytophotometry euploid polyploid atypia was also shown in every case, which is characteristic of benign hormonal dysplasia.  相似文献   
997.
The hepatotropic effect of nonsteroidal anti-inflammatory drugs (NSAID) such as indomethacin, voltaren, piroxicam, phenylbutazon, mefenamic acid was studied. It was found that according to their level of the pharmacological protection of the liver against tetrachlormethan these agents may be arranged in the following sequence: mefenamic acid, phenylbutazon, voltaren, piroxicam. The hepatoprotective effect of NSAID correlates with the antioxidant properties and fails to correlate with the antioxidant ones. The hepatotoxic effect of NSAID was determined by their ability to suppress synthesis of prostaglandins.  相似文献   
998.
999.
The trigone sensitivity test, a complementary test to cystometry, has been proposed as a method for distinguishing certain clinical disorders. Pressure is applied to the trigone region of the bladder by pulling upon a Foley catheter with the balloon inflated and the amount of force needed to induce an urge to void is recorded. Although the trigone sensitivity test has been proposed as a test of exteroceptive function, it is possible that deeper receptors, perhaps proprioceptors, are actually responsible for the awareness of the urge to void during the study. The present investigation compared the trigone sensitivity test with provoked detrusor contraction in 107 patients. The findings indicate that variations in the two responses occur independently of each other. It is concluded that different neural pathways are responsible for the two functions. The hypothesis that exteroceptive and not proprioceptive nerves are being measured during trigone sensitivity testing is supported by these findings.  相似文献   
1000.
Sebum excretion rate was measured by a photometric technique. We demonstrated a high correlation between sebum excretion rates on the left and right sides of the upper back and between back and forehead skin. Sebum excretion rate measurements overlying an open comedone (blackhead) were significantly lower than those obtained from normal skin. This observation demonstrates a functional obstruction to the outflow of sebum and would suggest that the lack of involvement of open comedones in inflammatory acne is not because of the maintenance of a free flow of sebum.  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