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   254333篇
  免费   23390篇
  国内免费   15824篇
耳鼻咽喉   2514篇
儿科学   2796篇
妇产科学   3148篇
基础医学   30646篇
口腔科学   4529篇
临床医学   31779篇
内科学   36755篇
皮肤病学   3523篇
神经病学   13068篇
特种医学   10080篇
外国民族医学   115篇
外科学   25856篇
综合类   40782篇
现状与发展   62篇
一般理论   28篇
预防医学   17200篇
眼科学   6917篇
药学   27568篇
  255篇
中国医学   14603篇
肿瘤学   21323篇
  2024年   893篇
  2023年   3806篇
  2022年   9920篇
  2021年   12740篇
  2020年   9494篇
  2019年   8265篇
  2018年   8755篇
  2017年   8108篇
  2016年   7867篇
  2015年   11994篇
  2014年   14681篇
  2013年   13852篇
  2012年   20236篇
  2011年   21783篇
  2010年   14101篇
  2009年   11277篇
  2008年   14649篇
  2007年   13847篇
  2006年   13259篇
  2005年   12472篇
  2004年   8434篇
  2003年   7937篇
  2002年   6576篇
  2001年   5217篇
  2000年   5102篇
  1999年   5010篇
  1998年   3025篇
  1997年   2998篇
  1996年   2328篇
  1995年   2241篇
  1994年   1999篇
  1993年   1223篇
  1992年   1621篇
  1991年   1429篇
  1990年   1155篇
  1989年   1086篇
  1988年   922篇
  1987年   795篇
  1986年   596篇
  1985年   485篇
  1984年   243篇
  1983年   198篇
  1982年   129篇
  1981年   146篇
  1980年   105篇
  1979年   124篇
  1978年   58篇
  1977年   53篇
  1976年   46篇
  1974年   48篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
目的探讨用游离自体腹白线片修补急性十二指肠溃疡穿孔的应用价值。方法从2006年1月至2006年7月对13例用自体腹白线片修补急性十二指肠溃疡穿孔的病人的临床资料和随访情况进行回顾性分析,其中2例穿孔大于2cm2,平均手术时间60分钟,平均失血量20ml,平均住院天数9±1天。结果游离自体腹白线片修补急性十二指肠溃疡穿孔13例均痊愈出院。随访15天至6个月,无手术并发症。结论本方法操作较简单、安全、效果好,其适应症广,是一种可行的新方法。  相似文献   
72.
OBJECTIVE: To investigate the serial CT findings of Paragonimus westermani infected dogs and the microscopic structures of the worm cysts using Micro-CT. MATERIALS AND METHODS: This study was approved by the committee on animal research at our institution. Fifteen dogs infected with P. westermani underwent serial contrast-enhanced CT scans at pre-infection, after 10 days of infection, and monthly thereafter until six months for determining the radiologic-pathologic correlation. Three dogs (one dog each time) were sacrificed at 1, 3 and 6 months, respectively. After fixation of the lungs, both multi-detector CT and Micro-CT were performed for examining the worm cysts. RESULTS: The initial findings were pleural effusion and/or subpleural ground-glass opacities or linear opacities at day 10. At day 30, subpleural and peribronchial nodules appeared with hydropneumothorax and abdominal or chest wall air bubbles. Cavitary change and bronchial dilatation began to be seen on CT scan at day 30 and this was mostly seen together with mediastinal lymphadenopathy at day 60. Thereafter, subpleural ground-glass opacities and nodules with or without cavitary changes were persistently observed until day 180. After cavitary change of the nodules, the migratory features of the subpleural or peribronchial nodules were seen on all the serial CT scans. Micro-CT showed that the cyst wall contained dilated interconnected tubular structures, which had communications with the cavity and the adjacent distal bronchus. CONCLUSION: The CT findings of paragonimiasis depend on the migratory stage of the worms. The worm cyst can have numerous interconnected tubular channels within its own wall and these channels have connections with the cavity and the adjacent distal bronchus.  相似文献   
73.
74.
目的 :探讨单纯疱疹性角膜炎是中西医联合用药的治疗方法。方法 :本组 10 0例 ( 10 6只眼 )单纯疱疹性角膜炎患者应用抗病毒药物联合清热解毒中药的疗效观察。结果 :本组病例治疗后总有效率 82 .0 8%。结论 :中西医联合治疗措施是我们对单纯疱疹性角膜炎治疗的一项新的探讨。  相似文献   
75.
76.
77.
In order to investigate the antagonistic effect of Glycyrrhiza Uralensis Fish (GUF) and Chelidonium maJus L (CML) on gastrccarcinogenesis induced by MNNG in Wastar rats, we treated the rats with MNNG alone (group 1) and with MNNG plus GUF and CML (group 2 and 3) respectively. The incidence of infiltrating adenocarcinoma of the glandular stomach and duodenum in group 2 was significantly lower than that in group 1 (26.7% vs. 67.8%). The differentiation and aggressivenees of carcinomas occured in group 2 were much better and mild than those in group 1. Present study also demonstrated that the inhibitory effect of CML on proliferation of human stomach carcinoma cell line MGC-803 was very remarkable; in addition, GUF and CML were able to antagonise the mutagenic activation of MNNG. These results suggest that GUF and CML may be empoyed in prevention of gastric carcinoma.  相似文献   
78.
 To monitor the lead hazards in industries and to investigate the prevalence of elevated blood lead levels (BLLs) in lead-exposed workers, a lead surveillance system (PRESS-BLLs) has been established and operated in Taiwan, Republic of China, since July 1993. A cohort of lead-exposed workers who received a periodic annual health examination at 55 accredited hospital laboratories was constructed. A total of 9807 separate BLL measurements were reported to the system in 1994. The mean BLL was 15.8 μg/dl in male workers and 11.6 μg/dl in female workers. The mean BLL of lead-exposed workers was significantly (P<0.05, z-test) higher than that of the general Taiwanese population (8.6 μg/dl for males and 6.7 μg/dl for females). In addition, the BLLs of 983 (10.0%) workers exceeded the regulatory action level (40 μg/dl for males; 30 μg/dl for females). The workplaces and homes of 57% of the workers with elevated BLLs were thoroughly investigated to determine the sources of lead contamination. These actions identified the causes of elevated BLLs and set up strategies to reduce workers’ lead exposure. The establishment of this occupational lead surveillance system represents a method for monitoring of lead hazards from occupational and environmental settings to prevent lead poisoning. The information acquired from the system can help in the setting up of a priority of prevention and the development of control measures. It is also useful for further monitoring of changes in the BLLs of the lead-exposed-worker cohort. The Health Department of Taiwan can use this information to evaluate the effectiveness of current industrial hygiene practice. Subjects with elevated BLLs have been medically treated and placed on long-term follow-up for sequelae. Received: 2 September 1996/Accepted: 29 November 1996  相似文献   
79.
80.
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