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   113948篇
  免费   10041篇
  国内免费   5101篇
耳鼻咽喉   1481篇
儿科学   1962篇
妇产科学   1567篇
基础医学   13117篇
口腔科学   2033篇
临床医学   13232篇
内科学   18315篇
皮肤病学   2539篇
神经病学   5579篇
特种医学   4921篇
外国民族医学   24篇
外科学   11595篇
综合类   15557篇
现状与发展   19篇
一般理论   18篇
预防医学   8768篇
眼科学   2658篇
药学   12109篇
  82篇
中国医学   5580篇
肿瘤学   7934篇
  2024年   287篇
  2023年   1349篇
  2022年   3387篇
  2021年   4844篇
  2020年   3473篇
  2019年   3322篇
  2018年   3507篇
  2017年   3286篇
  2016年   3396篇
  2015年   5130篇
  2014年   6441篇
  2013年   6924篇
  2012年   9951篇
  2011年   10208篇
  2010年   7195篇
  2009年   6079篇
  2008年   7298篇
  2007年   6816篇
  2006年   6401篇
  2005年   5578篇
  2004年   4210篇
  2003年   3864篇
  2002年   3300篇
  2001年   2213篇
  2000年   1836篇
  1999年   1552篇
  1998年   721篇
  1997年   728篇
  1996年   528篇
  1995年   467篇
  1994年   406篇
  1993年   270篇
  1992年   510篇
  1991年   425篇
  1990年   391篇
  1989年   359篇
  1988年   319篇
  1987年   257篇
  1986年   224篇
  1985年   207篇
  1984年   171篇
  1983年   128篇
  1982年   91篇
  1981年   92篇
  1980年   78篇
  1979年   141篇
  1978年   91篇
  1977年   79篇
  1975年   65篇
  1974年   65篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
To determine the genetic origin of the complete hydatidiform mole, 20 abnormal pregnancies were studied with restriction fragment length polymorphism with five genomic probes: EJ 6.6, beta-globin gene, 3'alpha-hypervariable region, J-Bir, and St14. In the 12 cases of molar pregnancy, pure paternal origin was proved in 11 cases, but both maternal and paternal inheritance were shown in only one case. In the cases with pure paternal origin, all of the restriction fragment length polymorphisms were homozygous, although those of the fathers were heterozygous at 15 loci. In the four cases that mimicked hydatidiform mole but were diagnosed as hydropic change of villi, both paternal and maternal inheritance were noted. In the four pregnancies with blighted ovum, both paternal and maternal inheritance were shown in three cases; and in one case with a balanced translocation between chromosomes 13 and 14, only paternal inheritance was noted. This study showed that most of the complete hydatidiform moles were caused by fertilization of an empty egg by a duplicated haploid sperm, but rare exceptions may exist.  相似文献   
34.
Measurement of patient satisfaction is an essential part of health outcome assessment. The purpose of this study is (a) to compare the stability of an aggregate summary measure and two separate summary measures of patient satisfaction; and, (b) to examine causal effects between two separate summary measures at two points in time. Data were collected from 1,451 Medicare HMO beneficiaries. In conclusion, (a) separate summary measures are recommended for constructing the measure of patient satisfaction and (b) moderate causal relationships and cross-lagged effects between the patient satisfaction measures of qualify of care and access to care were found.  相似文献   
35.
36.
37.
38.
39.
OBJECTIVE: To quantify the clinical impact of methicillin-resistance in Staphylococcus aureus causing infection complicated by bacteremia in adult patients, while controlling for the severity of patients' underlying illnesses. DESIGN: Retrospective cohort study from October 1, 1995, through December 31, 2003. PATIENTS AND SETTING: A total of 438 patients with S. aureus infection complicated by bacteremia from a single Veterans Affairs healthcare system. RESULTS: We found that 193 (44%) of the 438 patients had methicillin-resistant S. aureus (MRSA) infection and 114 (26%) died of causes attributable to S. aureus infection within 90 days after the infection was identified. Patients with MRSA infection had a higher mortality risk, compared with patients with methicillin-susceptible S. aureus (MSSA) infections (relative risk, 1.7 [95% confidence interval, 1.3-2.4]; P<.01), except for patients with pneumonia (relative risk, 0.7 [95% confidence interval, 0.4-1.3]). Patients with MRSA infections were significantly older (P<.01), had more underlying diseases (P=.02), and were more likely to have severe sepsis in response to their infection (P<.01) compared with patients with MSSA bacteremia. Patients who died within 90 days after S. aureus infection was identified were significantly older (P<.01) and more likely to have severe sepsis (P<.01) and pneumonia (P=.01), compared with patients who survived. After adjusting for age as a confounder, comorbidities, and pneumonia as an effect modifier, S. aureus infection-related mortality remained significantly higher in patients with MRSA infection than in those with MSSA infection, among those without pneumonia (hazard ratio, 1.8 [95% confidence interval, 1.2-3.0]); P<.01. CONCLUSIONS: The results of this study suggest that patients with MRSA infections other than pneumonia have a higher mortality risk than patients with MSSA infections other than pneumonia, independent of the severity of patients' underlying illnesses.  相似文献   
40.
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