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   102084篇
  免费   9050篇
  国内免费   3439篇
耳鼻咽喉   1635篇
儿科学   1627篇
妇产科学   1560篇
基础医学   14892篇
口腔科学   1821篇
临床医学   11093篇
内科学   18343篇
皮肤病学   2369篇
神经病学   7480篇
特种医学   5223篇
外国民族医学   21篇
外科学   11691篇
综合类   6716篇
现状与发展   14篇
一般理论   21篇
预防医学   6274篇
眼科学   2586篇
药学   9684篇
  38篇
中国医学   2832篇
肿瘤学   8653篇
  2023年   952篇
  2022年   2339篇
  2021年   4228篇
  2020年   2828篇
  2019年   3057篇
  2018年   3239篇
  2017年   2757篇
  2016年   3194篇
  2015年   4387篇
  2014年   5138篇
  2013年   5482篇
  2012年   7812篇
  2011年   7941篇
  2010年   4893篇
  2009年   4023篇
  2008年   5462篇
  2007年   5372篇
  2006年   4958篇
  2005年   4690篇
  2004年   3735篇
  2003年   3368篇
  2002年   2926篇
  2001年   2098篇
  2000年   2054篇
  1999年   1946篇
  1998年   993篇
  1997年   941篇
  1996年   762篇
  1995年   705篇
  1994年   615篇
  1993年   472篇
  1992年   962篇
  1991年   896篇
  1990年   800篇
  1989年   825篇
  1988年   799篇
  1987年   760篇
  1986年   649篇
  1985年   615篇
  1984年   469篇
  1983年   391篇
  1982年   267篇
  1981年   254篇
  1980年   220篇
  1979年   332篇
  1978年   276篇
  1977年   203篇
  1974年   226篇
  1973年   237篇
  1972年   192篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case–control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan–Meier analysis with log-rank test (P = 0.008). The AF group''s adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16–1.57; P = 0.009) according to Cox''s proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF.  相似文献   
35.
The cingulum, connecting the orbitofrontal cortex to the medial temporal lobe, involves in diverse cognition functions including attention, memory, and motivation. To investigate the relationship between the cingulum injury and cognitive impairment in patients with chronic mild traumatic brain injury, we evaluated the integrity between the anterior cingulum and the basal forebrain using diffusion tensor tractography in 73 patients with chronic mild traumatic brain injury(39 males, 34 females, age 43.29 ± 11.42 years) and40 healthy controls(22 males, 18 females, age 40.11 ± 16.81 years). The patients were divided into three subgroups based on the integrity between the anterior cingulum and the basal forebrain on diffusion tensor tractography: subgroup A(n = 19 patients)-both sides of the anterior cingulum were intact; subgroup B(n= 36 patients)-either side of the anterior cingulum was intact; and subgroup C(18 patients)-both sides of the anterior cingulum were discontinued. There were significant differences in total Memory Assessment Scale score between subgroups A and B and between subgroups A and C. There were no significant differences in diffusion tensor tractography parameters(fractional anisotropy, apparent diffusion coefficient, and fiber volume) between patients and controls. These findings suggest that the integrity between the anterior cingulum and the basal forebrain, but not diffusion tensor tractography parameter, can be used to predict the cognitive function of patients with chronic mild traumatic brain injury. This study was approved by Yeungnam University Hospital Institutional Review Board(approval No. YUMC-2014-01-425-010) on August 16, 2017.  相似文献   
36.
37.
While decreasing trend in gender differences in alcohol use disorders was reported in Western countries, the change in Asian countries is unknown. This study aims to explore the shifts in gender difference in alcohol abuse (AA) and dependence (AD) in Korea. We compared the data from two nation-wide community surveys to evaluate gender differences in lifetime AA and AD by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Face-to-face interviews using the Composite International Diagnostic Interview (CIDI) were applied to all subjects in 2001 (n=6,220) and 2011 (n=6,022). Male-to-female ratio of odds was decreased from 6.41 (95% CI, 4.81-8.54) to 4.37 (95% CI, 3.35-5.71) for AA and from 3.75 (95% CI, 2.96-4.75) to 2.40 (95% CI, 1.80-3.19) for AD. Among those aged 18-29, gender gap even became statistically insignificant for AA (OR, 1.59; 95% CI, 0.97-2.63) and AD (OR, 1.18; 95% CI, 0.80-2.41) in 2011. Men generally showed decreased odds for AD (0.55; 95% CI, 0.45-0.67) and women aged 30-39 showed increased odds for AA (2.13; 95% CI 1.18-3.84) in 2011 compared to 2001. Decreased AD in men and increased AA in women seem to contribute to the decrease of gender gap. Increased risk for AA in young women suggests needs for interventions.  相似文献   
38.
39.
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