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   60283篇
  免费   5898篇
  国内免费   3866篇
耳鼻咽喉   440篇
儿科学   1219篇
妇产科学   617篇
基础医学   5677篇
口腔科学   1023篇
临床医学   8091篇
内科学   7623篇
皮肤病学   674篇
神经病学   2443篇
特种医学   2283篇
外国民族医学   8篇
外科学   5841篇
综合类   12984篇
现状与发展   19篇
一般理论   3篇
预防医学   5388篇
眼科学   1268篇
药学   6422篇
  67篇
中国医学   3975篇
肿瘤学   3982篇
  2024年   212篇
  2023年   783篇
  2022年   1988篇
  2021年   2712篇
  2020年   2149篇
  2019年   1664篇
  2018年   1818篇
  2017年   1829篇
  2016年   1635篇
  2015年   2472篇
  2014年   3120篇
  2013年   3226篇
  2012年   4711篇
  2011年   5073篇
  2010年   3958篇
  2009年   3276篇
  2008年   3655篇
  2007年   3626篇
  2006年   3441篇
  2005年   2910篇
  2004年   2505篇
  2003年   2422篇
  2002年   2172篇
  2001年   1702篇
  2000年   1201篇
  1999年   873篇
  1998年   501篇
  1997年   534篇
  1996年   387篇
  1995年   315篇
  1994年   288篇
  1993年   185篇
  1992年   278篇
  1991年   242篇
  1990年   187篇
  1989年   187篇
  1988年   186篇
  1987年   133篇
  1986年   141篇
  1985年   125篇
  1984年   106篇
  1983年   67篇
  1982年   57篇
  1981年   67篇
  1979年   97篇
  1978年   56篇
  1974年   57篇
  1973年   73篇
  1972年   58篇
  1971年   62篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
彩色多普勒在心脏起搏器综合征诊断中的应用价值   总被引:1,自引:1,他引:0  
目的 :探讨运用彩色多普勒血流显像 (CDFI)并结合心电图 (ECG)诊断起搏器综合征 (PMS)的临床价值。方法 :对具有详实临床及ECG资料的心室按需 (VVI)起搏器安置患者 6 0例及对照组 4 8例进行CDEI检查 ,观察起搏组与对照组的三尖瓣返流 (TR)的发生率、返流程度 ,并分析二者之间的相关性。结果 :起搏组出现逆传P波 (即PMS阳性 )者 15例 ,CDFI检测出现TR者 2 0例 ,明显高于对照组 ,且PMS阳性者TR发生率明显高于PMS阴性者 ,表明安置VVI起搏器后出现逆传P波与TR的发生相关性良好。结论 :CDFI对PMS的诊断具有重要意义 ,尤其将ECG与CDFI结合应用有助于诊断率的提高。  相似文献   
32.
The utilization of medical services by patients is an important determinant of doctor productivity, but this factor does not appear to have been given much attention in previous studies. In order to answer the question of why is there a wide variation in doctor output at low level medical facilities in China, an analytical framework of doctor productivity and utilization is developed. The simulation model is used to produce data that can be analyzed by such a framework. Great uncertainty about patient flows is one reason for the average lower and varying doctor productivity in lower level health facilities. Until uncertainty can be reduced, more flexibility is needed at the lower level to cope with changing utilization patterns and patient characteristics. The management by doctors of non-patient care activities (preventive programmes, medical research, teaching, and administration) is crucial to any approach to using doctor resources more effectively and efficiently.  相似文献   
33.
A S McIntyre  R G Long 《Gut》1993,34(8):1102-1107
Recent evidence has suggested that colonic neoplasm may be missed in patients presenting with iron deficiency anaemia unless colonic investigations are performed on all patients even when an alternative cause has been found. This study prospectively surveyed 114 consecutive patients referred from family practitioners to an outpatient clinic for the investigation of iron deficiency anaemia to determine the diagnoses contributing to the anaemia, the usefulness of certain clinical features, and the role of colonic and other investigations in obtaining the diagnosis. Upper gastrointestinal lesions contributing to anaemia were identified in 45 patients while colonic lesions were found in 18. Twenty three patients had a non-gastrointestinal cause for anaemia and in 12 patients no cause was found. Only two patients were identified as having colonic neoplasia (a small adenomatous polyp in each case) coexisting with upper gastrointestinal lesions. Symptoms and signs had a sensitivity and specificity of upper gastrointestinal disease of 50% and 83% respectively, and 44% and 80% for colonic disease. Endoscopy had a high yield (42%) and duodenal biopsy identified coeliac disease in three patients (two were aged > 70 years) each of whom had normal folate values. Barium enema had a yield of 13%. All colonic carcinomas occurred in patients > 65 years. The coexistence of colonic cancer or large polyps with an upper gastrointestinal lesion identified at endoscopy was rare in outpatients referred from family practitioners. Clinical symptoms and signs were poor indicators of the investigations that will detect a cause for the anaemia.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
34.
35.
OBJECTIVE: To study the value of serum progesterone in selecting the candidate patients with ectopic pregnancy (EP) for methotrexate (MTX) treatment and in monitoring the effect of the treatment. METHODS: Thirty-seven EP patients who were given single-dose intramuscular injection with 50 mg/m2 MTX were divided into success and failure groups according to the effect of the treatment. The serum progesterone concentrations in these patients were measured and compared between the 2 groups, and the receiver-operator curves (ROC) were used to determine the critical serum progesterone levels for assessing the effect of MTX treatment. The time consumed respectively by serum progesterone and beta-human chorionic gonadotrophin (beta-hCG) decreasing to below normal level was also compared. RESULTS: The serum progesterone concentrations of the success group (7.93+/-2.02 ng/ml) were significantly lower than those of the failure group (14.53+/-1.72 ng/ml, P<0.05). The recommended critical level for assessing the effect of MTX treatment for EP patients was 11 ng/ml according to the ROC, and the time for serum progesterone decreasing to below normal level was significantly less than that for beta-hCG. CONCLUSION: Serum progesterone can be used as an index for selecting candidate EP patients for MTX treatment, and also as a good indicator for assessing the therapeutic effect after treatment.  相似文献   
36.
闫小宁  田庆  张建荣 《陕西中医》2006,27(11):1409-1410
目的:观察体针联合康体多治疗神经性皮炎的的疗效。方法:86例患者随机分为两组,治疗组采用体针针刺(双合谷、曲池、三阴交等)联合静滴康体多注射液,对照组单纯采用静滴康体多注射液。结果:治疗组总有效率100%,对照组88.9%,有显著性差异(P<0.05)。提示:本方法具有活血通经功效,可使肥厚苔藓化的皮损逐步变得光滑有弹性。  相似文献   
37.
目的评价经皮椎体成形术治疗脊柱疾病的临床应用价值.方法 56例多发骨髓瘤、溶骨性脊柱转移瘤、骨质疏松性椎体压缩性骨折患者应用经皮椎体成形术后,分24 h、3个月两阶段评估患者疼痛、术后X线片检查结果、椎体高度等指标.结果术后止痛效果良好,尤以骨质疏松性椎体压缩性骨折患者的止痛效果最好.无严重并发症. 结论经皮椎体成形术对骨质疏松性椎体压缩性骨折等脊柱疾病的止痛、稳固椎体等效果明显,可以谨慎开展.  相似文献   
38.
小脑延髓池的显微外科解剖研究   总被引:1,自引:1,他引:0  
目的研究小脑延髓池的显微外科解剖特征,探讨其临床意义.方法选择经10%福尔马林固定成人头颈标本15例,显微镜下(5~25倍)模拟枕下极外侧入路、颈-乳突入路和耳前颞下窝入路的手术操作,分别自后、侧和前方显露小脑延髓池内结构,详细观测其神经血管结构的形态特征.结果小脑延髓池位于延髓外侧,上至桥延沟,下达枕骨大孔,侧方沿枕骨形成蛛网膜袖套进入颈静脉孔和舌下神经管.舌咽神经、迷走神经和副神经的根丝自上而下起自橄榄体背侧、延髓和脊髓的后外侧沟,根丝逐级汇合后分别进入舌咽神经道和迷走神经道.椎动脉于小脑延髓池的下端入颅后经该池行向前上内进入延髓前池.小脑下后动脉(PICA)可分为延髓前段、延髓侧段、扁桃体延髓段、脉络膜扁桃体段和皮质段.主要的静脉有小脑延髓裂内静脉、延髓静脉、小脑岩面下组静脉和岩下桥静脉.结论小脑绒球和Luschka孔脉络丛复合体及颈静脉孔硬膜返折可作为辨认舌咽神经脑池段的解剖标志,深刻认识小脑延髓池的蛛网膜界限对手术处理累及小脑延髓池的不同性质病变,保护重要神经功能意义重大.  相似文献   
39.
40.
Visual Basic作为一门可视化的高级编程语言,已经在各高等院校作为计算机基础教育的一门主干课程,随着多媒体技术、校园网建设和互联网技术的发展,原来滞后的教学方法势必影响高校计算机基础教学的效果。本文针对医学院校的计算机基础教育,着重探讨在新的历史时期Visual Basic的教学方法。  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