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   380826篇
  免费   24284篇
  国内免费   2833篇
耳鼻咽喉   5203篇
儿科学   8218篇
妇产科学   10112篇
基础医学   53287篇
口腔科学   11826篇
临床医学   30243篇
内科学   78906篇
皮肤病学   8558篇
神经病学   27292篇
特种医学   13964篇
外国民族医学   82篇
外科学   60949篇
综合类   9958篇
现状与发展   1篇
一般理论   64篇
预防医学   17486篇
眼科学   9453篇
药学   31076篇
  1篇
中国医学   2194篇
肿瘤学   29070篇
  2021年   2710篇
  2019年   2792篇
  2018年   4585篇
  2017年   3471篇
  2016年   3582篇
  2015年   4084篇
  2014年   5777篇
  2013年   7449篇
  2012年   10154篇
  2011年   10316篇
  2010年   6265篇
  2009年   5893篇
  2008年   9560篇
  2007年   10419篇
  2006年   10309篇
  2005年   9373篇
  2004年   8879篇
  2003年   8580篇
  2002年   8267篇
  2001年   28255篇
  2000年   28782篇
  1999年   23667篇
  1998年   5172篇
  1997年   4262篇
  1996年   3840篇
  1995年   3486篇
  1994年   3110篇
  1993年   2848篇
  1992年   16052篇
  1991年   14819篇
  1990年   14158篇
  1989年   13963篇
  1988年   12585篇
  1987年   12062篇
  1986年   11104篇
  1985年   10325篇
  1984年   6912篇
  1983年   5601篇
  1982年   2721篇
  1979年   5478篇
  1978年   3347篇
  1977年   2971篇
  1975年   2642篇
  1974年   3064篇
  1973年   2865篇
  1972年   2830篇
  1971年   2775篇
  1970年   2510篇
  1969年   2547篇
  1968年   2251篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Praziquantel (PQT) is a racemic mixture. Intragastric gavage of (-)-, (+)- and (+/-)-PQT 100 mg/kg were used to study the liver first pass effects in rabbits. HPLC was used to determine the concentration of each compound in the portal and systemic circulation, and in the bile within 4h. The results showed that all drugs were absorbed rapidly from the gut into the portal vein. The serum concentration in the portal vein were similar. However, over 90% of PQT and its enantiomers were extracted in the first passage through the liver. Intrinsic metabolic clearances of the liver of (-)-, (+)- and (+/-)-PQT were 50.3, 174.4 and 52.6 L/h, respectively. The serum concentrations of the three drugs markedly decreased in the systemic circulation, especially that of (+)-PQT. The AUC of (+)-PQT was apparently lower than that of (-)- or (+/-)-PQT. From these results, it is assumed that the first pass effects of PQT and its enantiomers in the liver are pronounced and most likely stereoselective. Also, unchanged PQT and its enantiomers were found in the bile of the rabbits.  相似文献   
992.
993.
A perusal of the medical literature re- vealod only one case of giant nonmetallic in traocular foreign body, 15x11x7 mm, removed in China However, no mention was made of the operative result of the wounded eye in the report. Usually after removal of intraocular foriegn bodies, especially the giant ones, the eyeball becomes inevitably atrophied, thus it has to be enucleated soon after operation. We removed a giant intraocular metallic foreign body, measuring 18.1x9x1.5 mm and weighing 0.24 g, from the left eye of a patient at our clinic. Follow-up l year after operation found that the eyeball of the affected eye was good in appearance with preservation of partial vision.  相似文献   
994.
995.
996.
The effect of a carbon dioxide (CO2) pneumoperitoneum and its duration on rabbit follicular oocytes was assessed by evaluating fertilization and subsequent embryonic development rates. CO2 may cross the plasma membrane and form carbonic acid, which liberates H+, thus lowering the intracellular pH. There were no significant differences in arterial pH and [HCO3-] between CO2 and air treatment groups, whereas arterial pCO2 and pO2 were significantly increased in the CO2 treatment group. We found that the duration of pneumoperitoneum, irrespective of type of gas used, was negatively correlated with success of embryonic development. These findings necessitate that more attention be given to the gas used for creation of a pneumoperitoneum during egg retrieval for in vitro fertilization and an attempt be made to minimize duration of the pneumoperitoneum.  相似文献   
997.
A 16 year old girl with post-streptococcal glomerulonephritis developed acute rheumatic fever 19 days afterwards. Previous publications on concurrent post-streptococcal glomerulonephritis and acute rheumatic fever are reviewed.  相似文献   
998.
999.
1000.
Summary In a study of 11 adult patients with acute nonlymphocytic leukemia (ANLL), infusion therapy with high-dose VP-16 and intermediate-dose cytosine arabinoside was administered. Response was assessed with reference to bone marrow aspirations performed on days 1; 12, 13, or 14; and 21 of treatment. All 7 of the patients with ANLL in relapse achieved marrow hypoplasia, and 3 of them achieved complete response. LFTs were elevated in most patients but no evidence of hepatocellular necrosis was observed. It is concluded that the value of VP-16 in ANLL may have been underestimated in the past because of inadequate dosing.Abbreviations ANLL acute nonlymphocytic leukemia - CGL chronic granulocytic leukemia - DNR daunorubicin - VNC vincristine - ID Ara-C, intermediate-dose Ara-C (500 mg/m2 for 12 doses) - HD Ara-C, high-dose Ara-C (3 g/m2 for 12 doses) - SGGT serum glutamic transaminase - LDH lactic dehydrogenase - SGOT serum glutamic oxaloacetic transaminase  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