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   102023篇
  免费   9764篇
  国内免费   6728篇
耳鼻咽喉   1066篇
儿科学   1144篇
妇产科学   928篇
基础医学   10121篇
口腔科学   1590篇
临床医学   12317篇
内科学   13768篇
皮肤病学   942篇
神经病学   4997篇
特种医学   4194篇
外国民族医学   34篇
外科学   11854篇
综合类   20322篇
现状与发展   25篇
一般理论   10篇
预防医学   8302篇
眼科学   2306篇
药学   10679篇
  115篇
中国医学   6791篇
肿瘤学   7010篇
  2024年   450篇
  2023年   1602篇
  2022年   4051篇
  2021年   5303篇
  2020年   4228篇
  2019年   3203篇
  2018年   3439篇
  2017年   3266篇
  2016年   3135篇
  2015年   4914篇
  2014年   6000篇
  2013年   6288篇
  2012年   9276篇
  2011年   9590篇
  2010年   7001篇
  2009年   5658篇
  2008年   6378篇
  2007年   5950篇
  2006年   5461篇
  2005年   4718篇
  2004年   3311篇
  2003年   2998篇
  2002年   2347篇
  2001年   1639篇
  2000年   1383篇
  1999年   1197篇
  1998年   677篇
  1997年   659篇
  1996年   566篇
  1995年   496篇
  1994年   414篇
  1993年   266篇
  1992年   291篇
  1991年   279篇
  1990年   257篇
  1989年   212篇
  1988年   188篇
  1987年   175篇
  1986年   150篇
  1985年   132篇
  1984年   125篇
  1983年   85篇
  1982年   68篇
  1981年   64篇
  1980年   62篇
  1979年   60篇
  1978年   63篇
  1975年   47篇
  1974年   48篇
  1973年   44篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
928株革兰阴性杆菌耐药性监测   总被引:27,自引:4,他引:23  
目的:了解青岛地区临床分离的重要革兰阴性杆菌的耐药情况以指导合理用药。方法:2001年青岛3家医院临床分离的5种革兰阴性杆菌用Kirby-Bauer法进行药敏试验。结果:5种病原菌均占3家医院革兰阴性杆菌分离率的前5位,大肠埃希菌对氟喹诺酮类药物的耐药率达60%-87%,细菌对亚胺培南均呈高度敏感,但铜绿假单胞菌耐亚胺培南株占25.8%,头孢他啶的抗菌活性是三代头孢菌素中最高的;复方酶抑制剂表现出良好的抗菌活性。结论:细菌耐药问题仍是目前临床的严重问题,地域性的耐药性监测是必要的。  相似文献   
44.
The fit and fill of the femoral canal are critical to the success of cementless femoral stems in total hip arthroplasty. It is difficult for conventional stems to provide a good fit and fill for the femora of patients with secondary osteoarthritis. Based on measurements of 100 femora of these patients, we designed two types of Fukui Medical School (FMS) stems with a proximal lateral flare that differed in the medial radius. We compared the fit and fill of the FMS stems with those of four conventional stems, using computer simulation. The mean proximal fit and total fit of the FMS stems were 46% and 53% respectively, a significant improvement compared with the other stems examined. The mean fill of FMS stems was 82% at the lower end of the lesser trochanter and 84% at the upper end of the isthmus, values that were significantly higher than those of the other stems. Since September 1995, we have implanted FMS stems in 15 hips with secondary osteoarthritis. Radiographic evaluations showed that the canal fill of the FMS stems was significantly greater in the proximal femur compared with other stems previously inserted at our department. A summary of this paper was presented at the 9th Symposium on Computer-Assisted Radiology; June 1995, Berlin, and at the 8th International Symposium on Technology in Arthroplasty; September 1995, Puerto Rico.  相似文献   
45.
本实验制作不同程度心肌缺血的动物模型,以声处理5%人血白蛋白为超声造影剂进行心肌灌注造影,探讨MCE时间-强度曲线各指标与心肌缺血程度间的关系。结果表明:心肌显影的峰值强度和曲线下面积均与缺血程度呈显著负相关(相关系数分别为r=-0.98,P值<0.005;r=-0.94,P值<0.05),且能区分轻度、中度和重度三种程度的心肌缺血;而三项时间指标与心肌缺血程度间未发现显著性差异。本实验的初步结果表明,MCE是一项活体评估局部心肌血流灌注的有效方法。  相似文献   
46.
放射性肝纤维化过程的定量研究   总被引:6,自引:0,他引:6  
经^60Coγ线照射大鼠肝区,通过光镜、电镜和图像分析仪、宣研究了照后1年肝脏的病理改变。结果表明,30Gy组在照射后1年内逐渐发生了放射性肝纤维化病变。在肝纤维化发生过程中,肝细胞内糖原颗凿含量进行性减少,间质中胶原纤维含量进行性增加,网状纤维于照射1-3个月呈进行性增加。  相似文献   
47.
This study presents the result of 12–21 years' follow-up in a group of children with neonatal urinary tract infection (onset within 1 month after birth) in whom early renal growth retardation was noted without concomitant classical renal scarring. In all cases the neonatal infection was diagnosed and treated within a few days of onset and the patients were closely supervised thereafter. Renal length, parenchymal thickness and area were measured at urography. At first follow-up (22 children, mean age 4.1 years) a significant reduction of renal parenchymal thickness was noted. Long-term follow-up (18 patients, mean age 17 years) demonstrated a normalization of renal size in the entire group, although less complete in the subgroup with reflux. There were two major findings in the present study. Firstly, renal growth retardation was seen after neonatal infection, both with and without reflux. Secondly, normalization of renal size in previously small kidneys was demonstrated, suggesting that growth retardation can be a reversible phenomenon. The tendency for such normalization was slightly more marked in children without reflux. Reduction of parenchymal thickness without calyceal deformity, therefore, does not necessarily mean irreversible damage, and differentiation between permanent scarring and temporary growth retardation can thus only be made at later follow-up, possibly not until after puberty. The demonstration of renal growth retardation in spite of early diagnosis and treatment emphasizes the great vulnerability of the kidney in the newborn.  相似文献   
48.
Galanin-like immunoreactivity has been visualized in nerve fibers in the islets of Langerhans, suggesting an involvement of galanin in the neural regulation of islet function. In this study, we investigated the effects of galanin on basal and stimulated insulin and glucagon secretion by infusing the peptide at three different dose rates in rats. We also studied the direct effect of galanin on insulin secretion from freshly isolated rat islets. At 320 pmol/kg/min, but not at 20 or 80 pmol/kg/min, galanin lowered basal plasma insulin levels. In contrast, basal plasma glucagon levels were lowered by galanin already at 20 and 80 pmol/kg/min. Furthermore, galanin inhibited both glucose- and arginine-induced insulin release at all three dose levels, whereas arginine-induced glucagon release was not affected by galanin. Glucose-stimulated insulin secretion from isolated rat islets was dose-dependently suppressed by galanin (10-6-10-8M). Therefore, it is concluded that galanin in rats inhibits insulin secretion, both in vivo and in vitro, and that at lower dose levels, the peptide also inhibits basal glucagon release.  相似文献   
49.
目的 构建大鼠MMP1 3重组腺病毒载体。方法 将MMP1 3cDNA目的片段插入腺病毒柯氏质粒中 ,再将此质粒与腺病毒DNA末端蛋白复合物共转染 2 93细胞 ,通过同源重组构建MMP1 3 重组腺病毒载体。结果 MMP1 3 重组腺病毒载体经PCR鉴定正确 ,包装纯化后 ,检测病毒滴度为 4× 1 0 9PFU/ml。结论 成功地构建了RatMMP1 3 重组腺病毒载体 ,为下一步行MMP 1 3转基因治疗低顺应性膀胱的研究提供了条件  相似文献   
50.
报告12例疸性腔皮病患者的性别与年龄构成、并发症、实验室检查、治疗经过和结果,对该病的病因、治疗和预后进行了讨论。  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