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   9885篇
  免费   759篇
  国内免费   604篇
  11248篇
  2024年   26篇
  2023年   93篇
  2022年   262篇
  2021年   428篇
  2020年   312篇
  2019年   325篇
  2018年   354篇
  2017年   280篇
  2016年   412篇
  2015年   597篇
  2014年   666篇
  2013年   761篇
  2012年   852篇
  2011年   785篇
  2010年   488篇
  2009年   366篇
  2008年   505篇
  2007年   418篇
  2006年   396篇
  2005年   335篇
  2004年   280篇
  2003年   246篇
  2002年   239篇
  2001年   177篇
  2000年   190篇
  1999年   155篇
  1998年   94篇
  1997年   89篇
  1996年   86篇
  1995年   66篇
  1994年   68篇
  1993年   53篇
  1992年   93篇
  1991年   80篇
  1990年   78篇
  1989年   63篇
  1988年   47篇
  1987年   68篇
  1986年   46篇
  1985年   39篇
  1984年   36篇
  1983年   20篇
  1982年   25篇
  1980年   22篇
  1979年   26篇
  1978年   19篇
  1977年   21篇
  1975年   18篇
  1973年   21篇
  1972年   17篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
W C Wong  S H Tan  T Y Yick  E A Ling 《Acta anatomica》1990,138(4):318-326
The ultrastructure of the interstitial cells of Cajal (ICC) in the oesophagus of the monkey resembled that described in the oesophagus of other mammalian species but differed in their paucity and almost lack of smooth endoplasmic reticulum, caveolae and filaments. The plasmalemma of the ICC was in close contact (20- to 30-nm gaps) with that of smooth muscle cells. This may occasionally take the form of a desmosome, but gap junctions have not been observed. Vesiculated axon profiles, containing large granular or agranular vesicles were in close contact (20- to 30-nm gaps) with the plasmalemma of ICC. In a few vesiculated profiles a presynaptic density could be recognized. The intercalation of the ICC between the vesiculated axon profiles and the smooth muscle cells suggest a role in oesophageal motility. Between 3 and 21 days following bilateral vagotomy some ICC showed regressive changes such as increased electron density and shrinkage of the cytoplasm, crowding of the organelles and dissolution of the nuclear chromatin material. Axon profiles in the vicinity of the affected ICC contained glycogen granules suggesting injury. In late stages, the number of ICC and smooth muscle contacts was reduced. The results suggest that the vagus nerves exert a trophic influence on the ICC and that the intercellular relationships between ICC and smooth muscle cells possess a degree of plasticity. It is tentatively suggested that these vagal effects may be mediated via the oesophageal myenteric ganglia.  相似文献   
3.
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   
4.
5.
6.
7.
8.
9.
Isolation of a cDNA encoding human 40S ribosomal protein s3.   总被引:3,自引:1,他引:2       下载免费PDF全文
  相似文献   
10.
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