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   79589篇
  免费   7444篇
  国内免费   3096篇
耳鼻咽喉   747篇
儿科学   3032篇
妇产科学   1594篇
基础医学   7415篇
口腔科学   1382篇
临床医学   8411篇
内科学   8064篇
皮肤病学   885篇
神经病学   2889篇
特种医学   4071篇
外国民族医学   65篇
外科学   10280篇
综合类   12913篇
现状与发展   20篇
一般理论   1篇
预防医学   3375篇
眼科学   1124篇
药学   5644篇
  64篇
中国医学   2399篇
肿瘤学   15754篇
  2024年   219篇
  2023年   1334篇
  2022年   2635篇
  2021年   3438篇
  2020年   2933篇
  2019年   2730篇
  2018年   2581篇
  2017年   2839篇
  2016年   3073篇
  2015年   3246篇
  2014年   4993篇
  2013年   5222篇
  2012年   4452篇
  2011年   4904篇
  2010年   3961篇
  2009年   3896篇
  2008年   3863篇
  2007年   4153篇
  2006年   3732篇
  2005年   3338篇
  2004年   2844篇
  2003年   2458篇
  2002年   2231篇
  2001年   2010篇
  2000年   1642篇
  1999年   1474篇
  1998年   1281篇
  1997年   1205篇
  1996年   1049篇
  1995年   912篇
  1994年   798篇
  1993年   632篇
  1992年   522篇
  1991年   440篇
  1990年   343篇
  1989年   346篇
  1988年   323篇
  1987年   276篇
  1986年   208篇
  1985年   294篇
  1984年   255篇
  1983年   171篇
  1982年   218篇
  1981年   182篇
  1980年   126篇
  1979年   99篇
  1978年   79篇
  1977年   58篇
  1976年   52篇
  1975年   24篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
目的探讨自发性高血压大鼠颈动脉中抑癌基因P53和原癌基因c-jun、c-fos、c-myc mRNA的表达.方法用逆转录聚合酶链式反应检测两种基因的表达水平.正常雄性大鼠作为对照组.结果 SHR颈动脉中,抑癌基因P53和原癌基因c-jun、c-fos、c-myc均有高表达,较WKY差异有显著性(P<0.05).结论自发性高血压大鼠颈动脉组织中抑癌基因P53和原癌基因c-jun、c-fos、c-myc均有高表达,癌基因的活化可能与自发性高血压大鼠颈动脉血管重构有关.  相似文献   
52.
Orthotopic placement of in vitro propagated Dunning R3327 AT-3 tumor cells resulted in a greater percentage of tumor takes and a two-fold shift in the exponential growth curve compared to flank implantation. The orthotopic tumor appeared to disseminate preferentially to regional lymph nodes, rather than to the lungs which is characteristic of flank tumors. The results suggest an important role of stromal-epithelial interactions in the growth of this tumor. © 1995 Wiley-Liss, Inc.  相似文献   
53.
The case of a 75-year-old man with three synchronous carcinomas of the lung (large cell carcinoma, adenocarcinoma, and small cell carcinoma) is reported. This is the eighth well-documented case report in the literature; however, our case is the first to be reported with the newly described histological combination.  相似文献   
54.
We present herein the rare case of a young man who was found to have a solitary tumor in the right upper lobe of his lung by a routine chest X-ray. The tumor was removed by thoracoscopic surgery, and pathological examinations confirmed the diagnosis of a primary lymphangioma of the lung. A brief review of the available literature on this extremely rare type of benign tumor follows the case report.  相似文献   
55.
Short-chain alkyl esters of L-dopa were administered to rats and mice via oral and rectal routes. Plasma L-dopa esters and L-dopa were determined in the systemic and portal circulation by HPLC. A comparison of isopropyl, butyl, and 4-hydroxybutyl esters of L-dopa demonstrated significantly higher levels of the esters in both systemic and portal blood samples following rectal administration than following oral administration. In most cases, oral administration resulted in nondetectable (<0.01 µg/ml) levels of the esters in plasma. Correspondingly, the plasma levels of L-dopa itself were consistently higher following rectal administration. At very high oral doses (500 mg L-dopa equivalents/kg body weight), systemic plasma levels of the butyl ester could be detected (1.25 µg/ml at 10 min), which might indicate saturation of the esterase activity of the small intestine. These studies indicate that the systemic availability of L-dopa from short-chain alkyl esters of L-dopa may be best optimized by rectal administration, which avoids the relatively high esterase activity characteristic of the small intestine.  相似文献   
56.
A number of cross-over studies on sedation in outpatient oral surgery investigated the quality of sedation produced by intravenous or rectal administration of diazepam. The sedation methods were equally efficient with a mean dose of 0.24 mg/kg (range 0.1–0.4) for i.v. administration and 0.53 mg/kg (range 0.5–0.6) for rectal administration. Eighty-five percent of the patients preferred surgery under sedation and local anaesthesia to local anaesthesia alone. The patients preferred the session in which they experienced stronger sedation, regardless of the route of administration.  相似文献   
57.
胰腺肿瘤的B型超声诊断   总被引:4,自引:0,他引:4  
本文将资料完整的并经手术及病理证实的27例胰腺肿瘤初步小结。详细描述各例肿瘤的临床们诊与诊断、B型超声和手术情况,并重点讨论:临床们诊和B型超声未能检出的肿瘤,检出肿瘤大小较手术所见尺寸的要,10mm~40mm以及未见肿瘤浸润的原因。  相似文献   
58.
绝经后阴道出血852例临床分析   总被引:1,自引:0,他引:1  
探讨经经后阴道出血的原因,相关因素来指导临床实践。方法;对我院收治的852例绝经后阴道出血的临床资料进行回顾性分析。结果;以阴道炎最多269例、慢性宫颈炎188例,功能失调性子宫出血102例,宫内节育器98例,恶性肿瘤59例,以内膜癌 33例,卵巢恶性肿瘤次之16例。  相似文献   
59.
气管与主支气管肿瘤的影像诊断(附32例报告)   总被引:5,自引:1,他引:4  
作者对32例经病理证实的气管与主支气管良、恶性肿瘤的影像学表现进行分析,归纳为3型:腔内型、壁增厚型和腔内外型。后2种类型提示恶性,而无蒂的腔内型表现者不能鉴别良,恶性。作者还评价了常规体层、CT及MRI诊断气管与主支气管肿瘤的优、缺点,讨论了影像诊断的作用。  相似文献   
60.
Patients'attitudes to rectal drug administration   总被引:2,自引:0,他引:2  
H.A.L. Vyvyan  MB  BS  FRCA  Z. Hanafiah  MB  BS  FFARCSI 《Anaesthesia》1995,50(11):983-984
One hundred adult patients attending for day case surgery were surveyed by anonymous questionnaire in order to determine their attitudes to rectal drug administration. Fifty four patients did not want an analgesic drug (diclofenac sodium) administered rectally whilst under anaesthesia, all preferring to take it orally if available. Ninety eight patients thought that drugs administered per rectum should always be discussed with them beforehand and a few had very strong feelings about this route of administration. We suggest that prescribers of rectal diclofenac should always discuss it with patients pre-operatively. Whilst many are happy to have suppositories, some young patients are sensitive about this and prefer to take such medication by mouth.  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