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   21498篇
  免费   2223篇
  国内免费   26篇
耳鼻咽喉   202篇
儿科学   655篇
妇产科学   686篇
基础医学   3002篇
口腔科学   467篇
临床医学   2446篇
内科学   4451篇
皮肤病学   212篇
神经病学   1571篇
特种医学   680篇
外科学   3059篇
综合类   610篇
一般理论   51篇
预防医学   2546篇
眼科学   319篇
药学   1721篇
中国医学   18篇
肿瘤学   1051篇
  2022年   146篇
  2021年   367篇
  2020年   234篇
  2019年   349篇
  2018年   400篇
  2017年   323篇
  2016年   303篇
  2015年   359篇
  2014年   499篇
  2013年   757篇
  2012年   1064篇
  2011年   1217篇
  2010年   635篇
  2009年   604篇
  2008年   953篇
  2007年   1045篇
  2006年   960篇
  2005年   1007篇
  2004年   890篇
  2003年   884篇
  2002年   807篇
  2001年   637篇
  2000年   651篇
  1999年   565篇
  1998年   282篇
  1997年   227篇
  1996年   241篇
  1995年   220篇
  1994年   179篇
  1993年   174篇
  1992年   449篇
  1991年   492篇
  1990年   451篇
  1989年   417篇
  1988年   360篇
  1987年   388篇
  1986年   357篇
  1985年   349篇
  1984年   295篇
  1983年   248篇
  1982年   157篇
  1981年   150篇
  1979年   195篇
  1978年   146篇
  1977年   157篇
  1976年   126篇
  1974年   185篇
  1973年   166篇
  1972年   134篇
  1970年   133篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
103.
104.
This study investigates the effects of phorbol dibutyrate (PDB) on protein kinase C (PKC) activation, as assessed by the translocation of PKC activity from the cytosolic to the particulate fraction, in aortas and mesenteric arteries from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). The basal distribution of PKC activity between the cytosolic and particulate fractions of SHR and WKY aortas, and mesenteric arteries, was not significantly different. PDB induced a concentration-dependent decrease in cytosolic PKC activity in SHR and WKY aortas. PDB (0.01 microM) decreased cytosolic PKC activity to a greater magnitude in SHR aorta as compared to WKY aorta, while 1.0 microM PDB decreased cytosolic PKC activities to similar magnitudes in SHR and WKY aortas, and mesenteric arteries. These results suggest that the increased sensitivity of SHR vessels to contraction by phorbol esters may be due, at least in part, to the greater sensitivity of PKC in these vessels to phorbol ester activation.  相似文献   
105.
106.
OBJECTIVE: The aim was to measure erythropoietin levels in amniotic fluid and extraembryonic coelomic fluid from 7-12 weeks' gestation. SUBJECTS: Twenty healthy women with ultrasonographically normal first trimester pregnancies prior to surgical termination. METHODS: Paired samples of amniotic fluid and extraembryonic coelomic fluid were collected by transvaginal ultrasound guided needling. Erythropoietin was measured in both pregnancy fluids using a radioimmunoassay. RESULTS: There was a highly significant difference between erythropoietin levels in extraembryonic coelomic fluid (median level 15.45 mU/ml; range 6.8-32.1 mU/ml) and those in amniotic fluid (median 5.0 mU/ml; range < 5.0-5.8 mU/ml) (P < 0.0001; Mann-Whitney U-test). The levels of erythropoietin in maternal serum (median 15.4 mU/ml; range 5.6-29.4 mU/ml) were similar to those in the extra-embryonic coelom (P = 0.81; Mann-Whitney U-test). No relation was demonstrated between erythropoietin levels in amniotic fluid or coelomic fluid and stage of gestation. CONCLUSION: High levels of erythropoietin in coelomic fluid suggests that the hormone is involved in the process of human extraembryonic erythropoiesis. The exact regulatory role remains unknown.  相似文献   
107.
A case of right psoas abscess that was caused by duodenal perforation following the ingestion of a wooden skewer from a filet mignon is presented. Surgical repair of the perforation, drainage of the abscess and 5 days of intravenous antibiotics resulted in prompt recovery.  相似文献   
108.
109.
We quantified the financial implications of surgical complications following pancreas transplantation. We reviewed medical and financial records of 49 pancreas transplant recipients at the University of Michigan Health System (UMHS) between 1/6/2002 and 11/22/2004. The association of donor, transplant recipient and financial variables was assessed. The median costs to UMHS of procedures and follow-up were $92,917 for recipients without surgical complications versus $108,431 when a surgical complication occurred, a difference of $15,514 (p = 0.03). Median reimbursement by the payer was $17,363 higher in patients with a surgical complication (p = 0.001). Similar trends (higher insurer costs) were noted when stratifying by payer (public and private) and specific procedure (SPK and PAK). All parties (patient, physician, payer and medical center) should benefit from quality improvement, with payers having a financial interest in pancreas transplant surgical quality initiatives.  相似文献   
110.
Conventional follicle harvesting techniques for hair transplantation are limited by the available scalp donor hair. The development of an innovative technique of microsurgical single follicular unit extraction has made it possible to exploit body hair grafts for scalp transplantation. This case study reports on 18 months of follow-up on a patient with extensive scalp scarring who underwent a transplantation procedure using donor chest hair. The photographically documented results show a change in the length of the chest hair measuring an average of 4 cm at transplant to 15 cm by 18 months post-transplant. The transplanted chest grafts provided an excellent cosmetic result for hair replacement.  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