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   382443篇
  免费   24337篇
  国内免费   2830篇
耳鼻咽喉   5199篇
儿科学   8234篇
妇产科学   10147篇
基础医学   53624篇
口腔科学   11883篇
临床医学   30307篇
内科学   79267篇
皮肤病学   8595篇
神经病学   27497篇
特种医学   13996篇
外国民族医学   82篇
外科学   61150篇
综合类   9968篇
现状与发展   1篇
一般理论   65篇
预防医学   17553篇
眼科学   9472篇
药学   31193篇
  1篇
中国医学   2199篇
肿瘤学   29177篇
  2021年   2677篇
  2019年   2769篇
  2018年   4599篇
  2017年   3498篇
  2016年   3579篇
  2015年   4087篇
  2014年   5769篇
  2013年   7467篇
  2012年   10148篇
  2011年   10389篇
  2010年   6278篇
  2009年   5937篇
  2008年   9607篇
  2007年   10437篇
  2006年   10406篇
  2005年   9433篇
  2004年   8953篇
  2003年   8651篇
  2002年   8360篇
  2001年   28335篇
  2000年   28865篇
  1999年   23737篇
  1998年   5193篇
  1997年   4278篇
  1996年   3867篇
  1995年   3515篇
  1994年   3126篇
  1993年   2863篇
  1992年   16127篇
  1991年   14878篇
  1990年   14212篇
  1989年   14028篇
  1988年   12633篇
  1987年   12107篇
  1986年   11157篇
  1985年   10369篇
  1984年   6942篇
  1983年   5627篇
  1982年   2737篇
  1979年   5522篇
  1978年   3370篇
  1977年   2991篇
  1975年   2659篇
  1974年   3079篇
  1973年   2885篇
  1972年   2842篇
  1971年   2780篇
  1970年   2524篇
  1969年   2552篇
  1968年   2267篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
J T Mail  G J Becker  R W Holden  H Y Yune 《Angiology》1987,38(12):903-911
The postoperative patient may present with one or more of a variety of problems amenable to management by interventional radiologic techniques, which may be curative by themselves or may, in addition, require or allow successful surgical intervention. To optimize patient care, a good working relationship between the vascular surgeon and the interventional radiologist is essential. Consideration should be given to the patient's presenting signs and symptoms, the surgical history with its alteration of anatomy, the results of available noninvasive studies, and knowledge of various therapeutic alternatives. Vascular radiologic interventions include angioplasty, thrombolytic therapy, a combination of both angioplasty and thrombolysis, and newer techniques such as percutaneous valvectomy. In this report, examples of some of the experience at Indiana University are presented. Emphasis is placed on the appropriate approach to the patient.  相似文献   
992.
Ganciclovir is a new antiviral compound (also called BW B759U, DHPG, BIOLF-62, and 2'NDG) that has been used for the treatment of cytomegalovirus (CMV) retinopathy in immunocompromised patients (bone marrow recipients or acquired immune deficiency syndrome [AIDS] victims). The authors studied the eyes of three AIDS patients with CMV retinopathy who died while receiving ganciclovir chemotherapy. Gross, microscopic, and ultrastructural studies of these cases showed varying degrees of retinal scarring and active CMV lesions at the margins of the scars. CMV antigens were localized in cells at all layers of retina at the border of the lesions and in isolated cells in a perivascular location within histologically normal appearing retina. These areas probably represent sites of recrudescence when the drug is discontinued. In situ hybridization using a cloned complementary DNA (cDNA) probe of human CMV corroborated the immunocytologic localization of the virus. Ultrastructural studies showed megalic syncytial cells containing mostly capsids exclusively in the cell nucleus. The cytoplasmic electron-dense membrane-bound bodies that have characterized untreated cases of CMV retinopathy were absent in the treated cases. An attempt to isolate CMV in tissue culture from the vitreous and retina of one of the cases yielded a negative result. Our results indicate that ganciclovir does not effectively eliminate CMV from the retina nor does it suppress expression of all viral genes. Ganciclovir appears to function by limiting viral DNA synthesis and subsequent packaging of viral DNA into infectious units, thereby acting as a virostatic chemotherapeutic agent.  相似文献   
993.
Using a new instrument designed by the Authors having two cannulas to allow filling of a contrast medium exclusively in the cervical canal and uterine cavity, selective hysterography was performed for 22 cases of endometrial carcinoma. This method was useful not only for evaluation of the size, location and growth patterns but also for estimation of the cervical involvement of endometrial carcinoma.  相似文献   
994.
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   
995.
996.
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   
997.
998.
999.
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   
1000.
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   
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