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   24488篇
  免费   1910篇
  国内免费   110篇
耳鼻咽喉   154篇
儿科学   694篇
妇产科学   493篇
基础医学   3234篇
口腔科学   577篇
临床医学   2504篇
内科学   4983篇
皮肤病学   216篇
神经病学   2040篇
特种医学   884篇
外科学   3668篇
综合类   349篇
一般理论   42篇
预防医学   2231篇
眼科学   617篇
药学   1591篇
中国医学   58篇
肿瘤学   2173篇
  2024年   21篇
  2023年   213篇
  2022年   317篇
  2021年   740篇
  2020年   465篇
  2019年   643篇
  2018年   731篇
  2017年   523篇
  2016年   605篇
  2015年   741篇
  2014年   950篇
  2013年   1181篇
  2012年   1839篇
  2011年   1896篇
  2010年   1162篇
  2009年   1011篇
  2008年   1653篇
  2007年   1638篇
  2006年   1576篇
  2005年   1502篇
  2004年   1373篇
  2003年   1240篇
  2002年   1016篇
  2001年   488篇
  2000年   369篇
  1999年   329篇
  1998年   203篇
  1997年   174篇
  1996年   139篇
  1995年   108篇
  1994年   112篇
  1993年   93篇
  1992年   168篇
  1991年   139篇
  1990年   141篇
  1989年   134篇
  1988年   95篇
  1987年   98篇
  1986年   88篇
  1985年   76篇
  1984年   71篇
  1983年   59篇
  1982年   52篇
  1981年   52篇
  1980年   39篇
  1979年   40篇
  1978年   33篇
  1977年   36篇
  1976年   30篇
  1975年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
We carried out a nonrandomized, unblinded study to compare the efficacy of rifampin alone with that of rifampin in combination with trimethoprim in the eradication of the Haemophilus influenzae type b (HIB) carrier state among contacts of patients with invasive HIB infection. The study population comprised 17 index patients admitted to hospital with severe HIB infections and 233 contacts, 43 of whom had nasopharyngeal colonization with HIB of the same biotype as that of the index patient. Rifampin in a daily dose of 20 mg/kg (maximum 600 mg) for 4 days eradicated the carrier state in 86% of cases, as did the combination of rifampin at the same dosage and trimethoprim in a daily dose of 5 mg/kg (maximum 160 mg) for 4 days.  相似文献   
9.
Objective: The study goal was to compare the laser spot size created using reflective and refractive micromanipulators with a CO2 laser and to determine the sensitivity of spot size to laser power. Study Design and Setting: A CO2 laser and operating microscope (400-mm focal length) was coupled to either a reflective (Cassegrain-like) or refractive micromanipulator. Laser spot size was determined by measuring the region of ablation created by laser irradiation of wood (dry tongue depressors), exposed photographic film, and agar gel using optical micrometry. Laser power varied from 0.5 to 20 W with pulse durations of 0.1 and 0.5 second. Results: The reflective micromanipulator demonstrated overall smaller spot sizes for a given laser power and lower incremental change in spot size with increasing power. The reflective design demonstrated less sensitivity to increases in laser power. Conclusions: Micromanipulator optical design can result in significant differences in laser spot size. The reflective device used in this study demonstrated less sensitivity to increasing laser power. (Otolaryngol Head Neck Surg 2002;126:593-597.)  相似文献   
10.
Background and objective  The purpose of this study is to assess whether Chinese children with high apnea–hypopnea index (AHI) are sleepier by a modified Epworth Sleepiness Scale (ESS). Materials and methods  Records were retrospectively reviewed. We included children who were between 3 and 12 years old, admitted for overnight polysomnogram because of suspected obstructive sleep apnea syndrome (OSAS). A modified ESS was used to assess excessive daytime sleepiness (EDS) of the children. Results  One hundred ninety-two Chinese children were included. Children with high AHI, defined as AHI > 5.0, were sleepier than children with AHI less than or equal to 5. After adjustment by age, gender, and obesity, children with high AHI remained significantly sleepier. Modified ESS was significantly correlated with AHI (rho = 0.124, 95% CI = 0.004–0.281). Modified ESS score of >8 was the best cutoff point with the sensitivity and specificity of 0.29 and 0.91, respectively. The odds ratio of children with modified ESS > 10 having high AHI was 4.231 (95%CI = 1.248 to 14.338) and children with modified ESS > 8 had the highest odds ratio, 4.295(95%CI = 1.66 to 11.1), of having high AHI. Conclusion   Chinese children with high AHI appear to be sleepier than children with low AHI. Children with suspected OSAS and high modified ESS, i.e., ESS > 8, had significantly higher odds ratio of having high AHI. Increased sleepiness is a specific but not a sensitive symptom in snoring children with high AHI. Screening for EDS in snoring children may help us identify those with high AHI and prioritize the management of those children. All authors worked and the study was carried out in Kwong Wah Hospital in Hong Kong. There was no conflict of interest and no specific source of funding for the study.  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